Researcher Database

Iwano Hiroyuki
Hokkaido University Hospital Internal Medicine
Assistant Professor

Researcher Profile and Settings

Affiliation

  • Hokkaido University Hospital Internal Medicine

Job Title

  • Assistant Professor

Research funding number

  • 50622354

J-Global ID

Research Interests

  • 循環器   

Research Areas

  • Life sciences / Radiology

Academic & Professional Experience

  • 2018/10 - Today 北海道大学病院循環器内科 助教
  • 2016/04 - 2018/10 北海道大学大学院医学研究院循環病態内科学 助教
  • 2015/04 - 2016/03 北海道大学病院循環器内科 特任助教
  • 2014/10 - 2015/03 北海道大学病院循環器内科 医員
  • 2013/08 - 2014/09 University of Mississippi Medical Center
  • 2012/10 - 2013/07 Wake Forest University
  • 2012 Hokkaido University

Research Activities

Published Papers

  • Yasuyuki Chiba, Hiroyuki Iwano, Michito Murayama, Sanae Kaga, Ko Motoi, Suguru Ishizaka, Shingo Tsujinaga, Asuka Tanemura, Shinobu Yokoyama, Masahiro Nakabachi, Hisao Nishino, Kazunori Okada, Kiwamu Kamiya, Toshiyuki Nagai, Toshihisa Anzai
    Journal of the American Society of Echocardiography : official publication of the American Society of Echocardiography 2020/12/28
  • Hirokazu Komoriyama, Kazunori Omote, Toshiyuki Nagai, Yoshiya Kato, Nobutaka Nagano, Kazuhiro Koyanagawa, Kiwamu Kamiya, Takao Konishi, Takuma Sato, Yuta Kobayashi, Shingo Tsujinaga, Hiroyuki Iwano, Kengo Kusano, Satoshi Yasuda, Hisao Ogawa, Hatsue Ishibashi-Ueda, Toshihisa Anzai
    International journal of cardiology 321 113 - 117 2020/12/15 [Refereed][Not invited]
     
    BACKGROUND: The histopathological diagnosis of cardiac sarcoidosis (CS) is challenging because of sampling error in endomyocardial biopsy (EMB) and the determinants of positive EMB are unclear. Reduced left ventricular ejection fraction (LVEF) is a simple parameter of the extent of myocardial damage, and higher serum angiotensin-converting enzyme (ACE) activity would indicate the spread of disease activity in CS patients. Thus, we sought to examine whether these parameters are related to the histopathological diagnosis of CS by EMB. METHODS: A total of 94 consecutive clinically diagnosed CS patients between August 1986 and March 2019 who were admitted to two academic hospitals were examined. We determined EMB as positive if non-caseating epithelioid granulomas were confirmed in the myocardial tissue. Patients were divided into two groups according to positive (n = 37) and negative (n = 57) EMB. We assessed the relationship between LVEF, serum ACE activity and positive EMB. RESULTS: Multivariable analysis revealed that both LVEF and serum ACE were independently associated with positive EMB (OR 0.83, 95% CI 0.70-0.99; OR 1.39, 95% CI 1.02-1.90, respectively). Moreover, patients with both lower LVEF (<37%, median) and higher ACE activity (≥13.5 IU/L, median) had the highest frequency of positive EMB (p = .003). The combination of lower LVEF and higher serum ACE showed better specificity (91.2%) and positive predictive value (73.7%) than either LVEF or serum ACE alone for positive EMB. CONCLUSIONS: Lower LVEF and higher serum ACE activity were associated with positive EMB, suggesting that these parameters might be useful for predicting positive EMB in CS patients.
  • Takeshi Umazume, Takahiro Yamada, Itsuko Furuta, Hiroyuki Iwano, Mamoru Morikawa, Hidemichi Watari, Hisanori Minakami
    BMC pregnancy and childbirth 20 (1) 750 - 750 2020/12/02 
    BACKGROUND: This study aimed to compare the echocardiographic changes and cardiac biomarkers between women with singleton and twin pregnancies. METHODS: From April 2014 to March 2016, this longitudinal cohort study invited pregnant women who were scheduled to give birth at Hokkaido University Hospital. We analyzed prospectively collected data on simultaneously determined echocardiographic parameters and blood cardiac markers of 44 women with singleton and 22 women with twin pregnancies. Furthermore, we tested the mixed-effect models for echocardiographic parameters and cardiac biomarkers. RESULTS: During the third trimester and immediately postpartum (within 1 week after childbirth), the mean left atrial volume index and brain natriuretic peptide (BNP) level were significantly higher in women with twin pregnancies than in those with singleton pregnancies. Women with twin pregnancies also had significantly smaller second-trimester inferior vena cava diameters and significantly higher third-trimester creatinine levels than those with singleton pregnancies. BNP positively correlated with the left atrial volume index (β = 0.49, p < 0.01) and the ratio of early diastolic transmitral to mitral annular velocity (E/e') (β = 0.41, p < 0.01). At 1 month after childbirth in women with singleton pregnancies, BNP and N-terminal precursor protein BNP (NT-proBNP) fragments immediately postpartum negatively correlated with the later E/e' (r = - 0.33, p = 0.02 and r = - 0.36, p < 0.01, respectively). CONCLUSIONS: The intravascular cardiac load reached maximum within 1 week after childbirth and was greater in women with twin pregnancies than in those with singleton pregnancies. BNP/NT-proBNP significantly positively correlated with LA volume index and E/e'. In women with singleton pregnancies, BNP secreted immediately after childbirth might improve the diastolic functions 1 month after childbirth.
  • Hiroyuki Iwano, Kentaro Shibayama, Takeshi Kitai, Kenya Kusunose, Tetsuari Onishi, Hidekazu Tanaka, Toshihisa Anzai
    Journal of echocardiography 18 (4) 235 - 239 2020/12 [Refereed][Not invited]
     
    BACKGROUND: Early worsening heart failure (WHF), defined as worsening of symptoms and signs of heart failure requiring intensification of medical or mechanical therapy during an admission for acute decompensated heart failure (ADHF), has recently been recognized as a risk of morbidity or mortality after the discharge. Although echocardiographic parameters of left ventricular (LV) output has been shown to be associated with long-term outcome in heart failure patients, its predictive value for early WHF has not been elucidated. METHODS: Prospect trial to Elucidate the utility of EchocarDiography-based Cardiac output in acute heart failure (PREDICT) is a multicenter, nonrandomized, prospective observational study to test the predictive value of echocardiographic LV output parameters for early WHF in ADHF patients. We will enroll patients admitted to 16 participating hospitals due to ADHF who did not receive positive inotropic agents as an initial therapy. Primary outcome will be set at early WHF defined as need for initiation of positive inotropic agents within 7 days after the admission. Predictive accuracy will be compared between Doppler echocardiographic LV output (stroke distance, stroke volume index, and cardiac index) and low perfusion findings assessed by physical examination. RESULTS: N/A. CONCLUSIONS: The PREDICT is expected to provide large data set to test the predictive value of echocardiographic LV output for early WHF in ADHF patients.
  • Tomonari Harada, Masaru Obokata, Kazunori Omote, Hiroyuki Iwano, Takahiro Ikoma, Kenya Okada, Kuniko Yoshida, Toshimitsu Kato, Koji Kurosawa, Toshiyuki Nagai, Kazuaki Negishi, Toshihisa Anzai, Masahiko Kurabayashi
    European heart journal cardiovascular Imaging 2020/11/07 
    AIMS: This study sought to determine the independent and incremental prognostic value of semiquantitative measures of tricuspid regurgitation (TR) severity over right heart remodelling and pulmonary hypertension (PH) in heart failure with preserved ejection fraction (HFpEF). METHODS AND RESULTS: Echocardiography was performed on 311 HFpEF patients. TR severity was defined by the semiquantitative measures [i.e. vena contracta width (VCW) and jet area] and by the guideline-based integrated qualitative approach (absent, mild, moderate, or severe). All-cause mortality or heart failure hospitalization occurred in 101 patients over a 2.1-year median follow-up. There was a continuous association between TR severity and the composite outcome with a hazard ratio (HR) of 1.17 per 1 mm increase of VCW [95% confidence interval (CI) 1.08-1.26, P < 0.0001]. Compared with patients with the lowest VCW category (≤1 mm), RV-adjusted HRs for the outcome were 1.99 (95% CI 1.05-3.77), 2.63 (95% CI 1.16-5.95), and 5.00 (95% CI 1.60-15.7) for 1-3, 3-7, and ≥7 mm VCW categories, respectively. TR severity as defined by the guideline-based approach showed a similarly graded association, but it was no longer significant in models including PH. In contrast, VCW remained independently and incrementally associated with the outcome after adjusting for established prognostic factors, as well as RV diameter and PH (fully adjusted HR 1.14 per 1 mm, 95% CI 1.02-1.27, P = 0.02; χ2 58.8 vs. 51.5, P = 0.03). CONCLUSION: The current data highlight the potential value of the semiquantitative measures of TR severity for the risk stratification in patients with HFpEF.
  • Miwa Sarashina-Motoi, Hiroyuki Iwano, Ko Motoi, Suguru Ishizaka, Yasuyuki Chiba, Shingo Tsujinaga, Michito Murayama, Masahiro Nakabachi, Shinobu Yokoyama, Hisao Nishino, Kazunori Okada, Sanae Kaga, Toshihisa Anzai
    Journal of clinical ultrasound : JCU 2020/10/24 
    PURPOSE: To investigate the influence of changes in vortices within the left ventricle (LV) on energy efficiency (EE) in normal and diseased hearts. METHODS: We performed vector flow mapping echocardiography in 36 normal participants (N), 36 patients with dilated cardiomyopathy (D), and 36 patients with LV hypertrophy (H). The circulation of the main anterior vortex was measured as a parameter of vortex strength. Energy loss (EL) was measured for one cardiac cycle, and EE was calculated as EL divided by stroke work (SW), which represents the loss of kinetic energy per unit of LV external work. RESULTS: Circulation increased in the order of N, H, and D (N: 15 ± 4, D: 19 ± 8, H: 17 ± 6 × 10-3 m2 /s; analysis of variance [ANOVA] P < .01). Conversely, EE increased in the order of N, D, and H (N: 0.22 ± 0.07, D: 0.26 ± 0.16, H: 0.30 ± 0.16 10-5 J/mm Hg mL m s; ANOVA P = .04), suggesting worst EE in group H. We found a positive correlation between circulation and SW only in group N, and positive correlation between circulation and EE only in diseased groups (D: R = 0.55, P < .01; H: R = 0.44, P < .01). Multivariable analyses revealed that circulation was the independent determinant of EE in groups D and H. CONCLUSIONS: Enhanced vortices could be associated with effective increase in LV external work in normal hearts. Conversely, they were associated with loss of EE without an optimal increase in external work in failing hearts, regardless of the LV morphology.
  • Michito Murayama, Hiroyuki Iwano, Miwa Sarashina, Toshihisa Anzai
    Circulation journal : official journal of the Japanese Circulation Society 84 (11) 2036 - 2036 2020/10/23
  • Yasuyuki Chiba, Kiwamu Kamiya, Tadao Aikawa, Hiroyuki Iwano, Toshiyuki Nagai, Takahiro Ishigaki, Yasushige Shingu, Ai Shimizu, Yoshiro Matsui, Toshihisa Anzai
    Journal of nuclear cardiology : official publication of the American Society of Nuclear Cardiology 27 (5) 1841 - 1843 2020/10 [Refereed][Not invited]
  • Takahide Kadosaka, Shingo Tsujinaga, Hiroyuki Iwano, Kiwamu Kamiya, Azusa Nagai, Yoshifumi Mizuguchi, Ko Motoi, Kazunori Omote, Toshiyuki Nagai, Ichiro Yabe, Toshihisa Anzai
    ESC heart failure 2020/09/11 
    Anti-mitochondrial antibody (AMA)-positive myositis is an atypical inflammatory myopathy characterized by chronic progressive respiratory muscle weakness, muscular atrophy, and cardiac involvement. Arrhythmias, cardiomyopathy, and myocarditis have been reported as cardiac manifestations. Herein, we present the first report of a patient diagnosed with having AMA-positive myositis with cardiac involvement mimicking cardiac sarcoidosis.
  • Kazuhiro Koyanagawa, Yuta Kobayashi, Tadao Aikawa, Atsuhito Takeda, Hideaki Shiraishi, Satonori Tsuneta, Noriko Oyama-Manabe, Hiroyuki Iwano, Toshiyuki Nagai, Toshihisa Anzai
    Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine 2020/09/07 
    To assess myocardial fibrosis associated with muscular dystrophy, T1-mapping and extracellular volume fraction (ECV) quantification was prospectively performed using cardiovascular MR (CMR) imaging in 6 male patients with muscular dystrophy and 5 female putative carriers of Duchenne or Becker muscular dystrophy. Five patients and all putative carriers had an elevated ECV (>29.5% for men and >35.2% for women), suggesting that ECV has a potential to detect diffuse fibrotic changes in patients and putative carriers of muscular dystrophy.
  • Yoshiya Kato, Toshiyuki Nagai, Noriko Oyama-Manabe, Satonori Tsuneta, Michikazu Nakai, Yuta Kobayashi, Hirokazu Komoriyama, Kazunori Omote, Shingo Tsujinaga, Takuma Sato, Takao Konishi, Kiwamu Kamiya, Hiroyuki Iwano, Toshihisa Anzai
    JACC. Cardiovascular imaging 13 (9) 2050 - 2052 2020/09 [Refereed][Not invited]
  • Shingo Tsujinaga, Hiroyuki Iwano, Tomohiro Oshino, Takahide Kadosaka, Yoshifumi Mizuguchi, Ko Motoi, Yasuyuki Chiba, Taro Koya, Taro Temma, Kiwamu Kamiya, Arata Fukushima, Takuya Koizumi, Tomoya Sato, Sakae Takenaka, Atsushi Tada, Suguru Ishizaka, Miwa Sarashina, Kazunori Omote, Rui Kamada, Takao Konishi, Takuma Sato, Toshiyuki Nagai, Hiroko Yamashita, Toshihisa Anzai
    Internal medicine (Tokyo, Japan) 59 (17) 2155 - 2160 2020/09/01 [Refereed][Not invited]
     
    Epirubicin-based chemotherapy carries a risk of inducing heart failure, although the frequency is rare. Bevacizumab, an anti-vascular endothelial growth factor monoclonal antibody, has recently been widely used in patients with recurrent breast cancer as a first-line chemotherapeutic agent. Heart failure or arterial thromboembolism has been reported as a rare cardiovascular complication of bevacizumab. We herein report a breast cancer patient with reversible cancer therapeutics-related cardiac dysfunction associated with bevacizumab and epirubicin complicating intracardiac thrombi in the left atrium and left ventricle. This case underscores the importance of tailored medical planning according to the individual status in patients receiving anti-cancer therapies.
  • Hiroyuki Iwano, Shinobu Yokoyama, Kiwamu Kamiya, Toshiyuki Nagai, Shingo Tsujinaga, Miwa Sarashina, Suguru Ishizaka, Yasuyuki Chiba, Masahiro Nakabachi, Hisao Nishino, Michito Murayama, Kazunori Okada, Sanae Kaga, Toshihisa Anzai
    Heart and vessels 35 (8) 1079 - 1086 2020/08 [Refereed][Not invited]
     
    BACKGROUND: A v wave on pulmonary artery wedge (PAW) pressure sometimes augments and appears on pulmonary artery (PA) pressure wave in patients with heart failure (HF). However, the significance of PA v wave in HF remains to be elucidated. METHODS: We retrospectively analyzed pressure waveforms in 61 HF patients (left ventricular ejection fraction 35 ± 15%). On the PAW and PA pressure waveforms, mean pressure as well as peak and amplitude of v waves (ampPAWv and ampPAv, respectively) were measured. Occurrence of worsening HF and cardiac death was recorded for 2 years after the catheterization. RESULTS: The ampPAWv did not correlate with ampPAv. When the patients were divided into 4 groups: I (high-ampPAWv/high-ampPAv), II (high-ampPAWv/low-ampPAv), III (low-ampPAWv/high-ampPAv), and IV (low-ampPAWv/low-ampPAv), the prevalence of group III was low (I: 13, II: 17, III: 4, IV: 27). Mean pressures of PAW and PA were similarly elevated in groups I and II. Cardiac index was lowest (I: 2.0 ± 0.4, II: 2.8 ± 0.6, III: 2.2 ± 0.2, IV: 2.4 ± 0.6 L/min/m2, ANOVA P < 0.01, P < 0.01 for I vs II) and tricuspid annular plane systolic excursion / systolic PA pressure was impaired (I: 0.27 ± 0.07, II: 0.48 ± 0.22, III: 0.59 ± 0.35, IV: 0.68 ± 0.35 mm/mmHg, ANOVA P < 0.01) in group I. During the follow-up, 13 events were observed. Kaplan-Meier analysis showed that patients in group I were at highest risk of cardiac events. CONCLUSIONS: PA v was observed mainly in patients with augmented PAW v wave and decreased cardiac index, suggesting an advanced stage of HF. Moreover, augmented PAv was associated with worse outcome in HF patients.
  • Takahide Kadosaka, Shingo Tsujinaga, Hiroyuki Iwano, Noriko Oyama-Manabe, Toshihisa Anzai
    JACC: Case Reports 2666-0849 2020/07 [Refereed][Not invited]
  • Shingo Tsujinaga, Hiroyuki Iwano, Yasuyuki Chiba, Suguru Ishizaka, Miwa Sarashina, Michito Murayama, Masahiro Nakabachi, Hisao Nishino, Shinobu Yokoyama, Kazunori Okada, Sanae Kaga, Toshihisa Anzai
    Circulation Reports 2 (5) 271 - 279 2020/05/08 [Refereed][Not invited]
  • Mechanisms of ventilatory inefficiency during exercise in heart failure: comparison between heart failure with preserved ejection fraction and reduced ejection fraction
    Tsujinaga S, Iwano H, Chiba Y, Ishizaka S, Sarashina M, Murayama M, Nakabachi M, Nishino H, Yokoyama S, Okada K, Kaga S, Anzai T
    Circulation Reports. 2020/03 [Refereed][Not invited]
  • Yuta Kobayashi, Kazunori Omote, Toshiyuki Nagai, Kiwamu Kamiya, Takao Konishi, Takuma Sato, Yoshiya Kato, Hirokazu Komoriyama, Shingo Tsujinaga, Hiroyuki Iwano, Kazuhiro Yamamoto, Tsutomu Yoshikawa, Yoshihiko Saito, Toshihisa Anzai
    The American journal of cardiology 125 (5) 772 - 776 2020/03/01 [Refereed][Not invited]
     
    Elevated serum uric acid (UA) is associated with an increased risk of cardiovascular disease and worse clinical outcome in patients with cardiovascular disease. Nevertheless, the prognostic value of serum UA level in hospitalized heart failure patients with preserved ejection fraction (HFpEF) has not been fully elucidated. The aim of this study was to investigate whether serum UA level on admission could be associated with subsequent mortality in hospitalized patients with HFpEF. We examined 516 consecutive hospitalized HFpEF (left ventricular ejection fraction ≥50%) patients with decompensated heart failure from our HFpEF-specific multicenter registry who had serum UA data on admission. The primary outcome of interest was all-cause death. During a median follow-up period of 749 (interquartile range 540 to 831) days, 90 (17%) patients died. Higher serum UA level was significantly related to increased incidence of all-cause death (p = 0.016). In addition, patients with higher serum UA (≥6.6 mg/dl, median) and plasma B-type natriuretic peptide (≥401.2 pg/ml, median) levels had the highest incidence of all-cause death in the groups (p = 0.002). In multivariable Cox regression analysis, serum UA was an independent determinant of mortality (hazards ratio 1.23, 95% confidence interval 1.10 to 1.39) even after adjustment for prespecified confounders, renal function and the use of diuretics before admission. In conclusions, higher admission serum UA was an independent determinant of mortality in hospitalized HFpEF patients. Our findings indicate the importance of assessing admission serum UA level for further risk stratification in hospitalized patients with HFpEF.
  • Taro Temma, Toshiyuki Nagai, Masaya Watanabe, Rui Kamada, Yumi Takahashi, Hikaru Hagiwara, Taro Koya, Motoki Nakao, Kazunori Omote, Kiwamu Kamiya, Hiroyuki Iwano, Kazuhiro Yamamoto, Tsutomu Yoshikawa, Yoshihiko Saito, Toshihisa Anzai
    Circulation journal : official journal of the Japanese Circulation Society 84 (3) 397 - 403 2020/02/25 [Refereed][Not invited]
     
    BACKGROUND: Atrial fibrillation (AF) is an important prognostic determinant in heart failure (HF) with preserved ejection fraction (HFpEF). However, it is unclear which HFpEF phenotypes are affected by AF in terms of long-term clinical outcomes because HFpEF is a heterogeneous syndrome with comorbidities such as coronary artery disease (CAD). In this study we determined the differential prognostic significance of AF in HFpEF patients according to CAD status.Methods and Results:Data for 408 hospitalized HFpEF patients enrolled in the Japanese Heart Failure Syndrome with Preserved Ejection Fraction Nationwide Multicenter Registry were analyzed. Patients were divided into 4 groups according to the presence of AF and CAD. The primary outcome was the composite of all-cause death and HF rehospitalization. The incidence of adverse events was higher in the AF-non-CAD than non-AF-non-CAD group (P=0.004). On multivariable Cox regression analysis with prespecified confounders, AF-non-CAD was significantly associated with an increased risk of adverse events than non-AF-non-CAD (adjusted HR, 1.91; 95% CI: 1.02-3.92) regardless of the type of AF. In contrast, risk was comparable between the AF-CAD and non-AF-CAD groups (adjusted HR, 1.24; 95% CI: 0.64-2.47). CONCLUSIONS: In HFpEF patients without CAD, AF was independently related to adverse events, indicating that intensive management of AF would have more beneficial effects particularly in HFpEF patients without CAD.
  • Kazunori Omote, Toshiyuki Nagai, Hiroyuki Iwano, Shingo Tsujinaga, Kiwamu Kamiya, Tadao Aikawa, Takao Konishi, Takuma Sato, Yoshiya Kato, Hirokazu Komoriyama, Yuta Kobayashi, Kazuhiro Yamamoto, Tsutomu Yoshikawa, Yoshihiko Saito, Toshihisa Anzai
    ESC heart failure 7 (1) 167 - 175 2020/02 [Refereed][Not invited]
     
    AIMS: The prognostic implication of left ventricular outflow tract velocity time integral (LVOT-VTI) on admission in hospitalized heart failure with preserved ejection fraction (HFpEF) patients has not been determined. We sought to investigate whether LVOT-VTI on admission is associated with worse clinical outcomes in hospitalized patients with HFpEF. METHODS AND RESULTS: We studied consecutive 214 hospitalized HFpEF patients who had accessible LVOT-VTI data on admission, from a prospective HFpEF-specific multicentre registry. The primary outcome of interest was the composite of all-cause death and readmission due to heart failure. During a median follow-up period of 688 (interquartile range 162-810) days, the primary outcome occurred in 83 patients (39%). The optimal cut-off value of LVOT-VTI for the primary outcome estimated by receiver operating characteristic analysis was 15.8 cm. Lower LVOT-VTI was significantly associated with the primary outcome compared with higher LVOT-VTI (P = 0.005). Multivariable Cox regression analyses revealed that lower LVOT-VTI was an independent determinant of the primary outcome (hazard ratio 0.94, 95% confidence interval 0.91-0.98). In multivariable linear regression, haemoglobin level was the strongest independent determinant of LVOT-VTI among clinical parameters (β coefficient = -0.61, P = 0.007). Furthermore, patients with lower LVOT-VTI and anaemia had the worst clinical outcomes among the groups (P < 0.001). CONCLUSIONS: Lower admission LVOT-VTI was an independent determinant of worse clinical outcomes in hospitalized HFpEF patients, indicating that LVOT-VTI on admission might be useful for categorizing a low-flow HFpEF phenotype and risk stratification in hospitalized HFpEF patients.
  • Atsushi Tada, Takao Konishi, Takuma Sato, Tomoya Sato, Takuya Koizumi, Sakae Takenaka, Yoshifumi Mizuguchi, Takahide Kadosaka, Ko Motoi, Yuta Kobayashi, Hirokazu Komoriyama, Yoshiya Kato, Kazunori Omote, Shingo Tsujinaga, Rui Kamada, Kiwamu Kamiya, Hiroyuki Iwano, Toshiyuki Nagai, Nanase Okazaki, Yoshihiro Matsuno, Toshihisa Anzai
    Cardiology journal 27 (4) 443 - 444 2020
  • 心エコー法とMRIによる肺動脈弁逆流重症度に乖離を認めた総動脈幹症の術後症例
    岩野 弘幸, 村山 迪史, 山澤 弘州, 武田 充人, 真鍋 徳子, 石森 直樹, 千葉 泰之, 石坂 傑, 更科 美羽, 辻永 真吾, 中鉢 雅大, 加賀 早苗, 安斉 俊久
    日本成人先天性心疾患学会雑誌 日本成人先天性心疾患学会 9 (1) 288 - 288 2020/01 [Refereed][Not invited]
  • 心エコー法とMRIによる肺動脈弁逆流重症度に乖離を認めた総動脈幹症の術後症例
    岩野 弘幸, 村山 迪史, 山澤 弘州, 武田 充人, 真鍋 徳子, 石森 直樹, 千葉 泰之, 石坂 傑, 更科 美羽, 辻永 真吾, 中鉢 雅大, 加賀 早苗, 安斉 俊久
    日本成人先天性心疾患学会雑誌 日本成人先天性心疾患学会 9 (1) 288 - 288 2020/01 [Refereed][Not invited]
  • Kazunori Omote, Toshiyuki Nagai, Kiwamu Kamiya, Tadao Aikawa, Shingo Tsujinaga, Yoshiya Kato, Hirokazu Komoriyama, Hiroyuki Iwano, Kazuhiro Yamamoto, Tsutomu Yoshikawa, Yoshihiko Saito, Toshihisa Anzai
    Journal of cardiac failure 25 (12) 978 - 985 2019/12 [Refereed][Not invited]
     
    BACKGROUND: Doppler-estimated peak systolic tricuspid regurgitation pressure gradient (TRPG) is a representative noninvasive parameter for evaluating pulmonary artery systolic pressure, which can be a determinant of adverse outcomes in chronic heart failure with preserved ejection fraction (HFpEF). However, the prognostic implications of TRPG at admission for hospitalized patients with HFpEF are undetermined. METHODS AND RESULTS: We examined 469 consecutive hospitalized patients with decompensated HFpEF (left ventricular ejection fraction ≥ 50%) who underwent TRPG measurement at admission in our HFpEF multicenter registry. The primary outcome of interest was all-cause death. Admission TRPG was significantly correlated with estimated pulmonary capillary wedge pressure and left atrial dimension (r = 0.24, P < 0.001 and r = 0.21, P < 0.001, respectively). During a median follow-up period of 748 (IQR 540-820) days, 83 patients died. Higher TRPG was significantly associated with higher mortality compared to lower TRPG (log-rank; P = 0.007). Multivariable analysis revealed that elevated TRPG was an independent determinant of mortality (HR 1.02, 95% CI 1.01-1.04, P = 0.008) after adjustment for prespecified confounders and renal function. CONCLUSIONS: Elevated TRPG at admission was an independent determinant of mortality in hospitalized patients with HFpEF, indicating that TRPG at admission could be a useful marker for risk stratification in these patients.
  • Shingo Tsujinaga, Hiroyuki Iwano, Suguru Ishizaka, Yasuyuki Chiba, Miwa Sarashina, Michito Murayama, Masahiro Nakabachi, Shinobu Yokoyama, Hisao Nishino, Kazunori Okada, Sanae Kaga, Takuma Sato, Toshihisa Anzai
    CIRCULATION 140 0009-7322 2019/11 [Refereed][Not invited]
     
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  • Yasushige Shingu, Hiroyuki Iwano, Tatsuya Murakami, Nobuyasu Katoh, Tomonori Ooka, Hiroki Katoh, Suguru Kubota, Yoshiro Matsui
    General thoracic and cardiovascular surgery 67 (10) 849 - 854 2019/10 [Refereed][Not invited]
     
    OBJECTIVES: While it was reported that patients with residual moderate mitral regurgitation (MR) after surgical aortic valve replacement (SAVR) had a poorer prognosis than those without it, the risk factors for residual MR have not been fully elucidated. The aim of the study was to evaluate risk factors for residual MR after SAVR. METHODS: Of the 222 patients who underwent isolated SAVR from 2001 to 2018, 33 (11 men; age: 74 ± 7 years) had functional moderate MR before surgery. The risk factors for residual MR were evaluated by comparing patients with residual moderate MR (n = 11, 33%) with those who exhibited improved post-surgery MR (n = 22, 67%). RESULTS: The left atrial diameter was significantly larger in the residual MR group (51 ± 7 mm) than in the improved MR group (46 ± 5 mm; P = 0.049). The mean pressure gradient at the aortic valve was significantly smaller in the residual MR group (52 ± 18 mmHg) than in the improved MR group (69 ± 22 mmHg; P = 0.043). A ratio of left atrial diameter (mm) and mean aortic valve pressure gradient (mmHg) greater than 0.9 predicted residual MR with a sensitivity of 70% and a specificity of 74% (area under the ROC curve: 0.779; P = 0.015). CONCLUSIONS: In patients with severe aortic valve stenosis and moderate MR, a high ratio of preoperative left atrial diameter and mean aortic valve pressure gradient would be a parameter predicting residual moderate MR post-SAVR.
  • Michito Murayama, Kazunori Okada, Sanae Kaga, Hiroyuki Iwano, Shingo Tsujinaga, Miwa Sarashina, Masahiro Nakabachi, Shinobu Yokoyama, Hisao Nishino, Mutsumi Nishida, Hitoshi Shibuya, Nobuo Masauzi, Toshihisa Anzai, Taisei Mikami
    The international journal of cardiovascular imaging 35 (10) 1871 - 1880 2019/10 [Refereed][Not invited]
     
    It was recently shown that invasively determined right ventricular (RV) stiffness was more closely related to the prognosis of patients with pulmonary hypertension than RV systolic function. So far, a completely noninvasive method to access RV stiffness has not been reported. We aimed to clarify the clinical usefulness of our new echocardiographic index of RV operating stiffness using atrial-systolic descent of the pulmonary artery-RV pressure gradient derived from pulmonary regurgitant velocity (PRPGDAC) and tricuspid annular plane movement during atrial contraction (TAPMAC). We studied 81 consecutive patients with various cardiac diseases who underwent echocardiography and cardiac catheterization. We measured PRPGDAC and TAPMAC using continuous-wave Doppler and M-mode echocardiography, respectively, and calculated PRPGDAC/TAPMAC. RV end-diastolic pressure (RVEDP) and RV pressure increase during atrial contraction (ΔRVPAC) were invasively measured, and RV volume change during atrial contraction (ΔVAC) was calculated from echocardiographic late-diastolic transtricuspid flow time-velocity integral and tricuspid annular area; thus ΔRVPAC/ΔVAC was used as the standard index for RV operating stiffness. PRPGDAC/TAPMAC well correlated with ΔRVPAC/ΔVAC (r = 0.84, p < 0.001) and RVEDP (r = 0.80, p < 0.001), and the area under the receiver operating characteristic curve to discriminate RVEDP > 12 mmHg was 0.94. Multivariate regression analysis revealed that PRPGDAC/TAPMAC was the single independent determinant of ΔRVPAC/ΔVAC (β = 0.86, p < 0.001). PRPGDAC/TAPMAC is useful to estimate RV operating stiffness and a good practical indicator of RVEDP.
  • Yumi Takahashi, Hiroyuki Iwano, Ippei Nakano, Arata Fukushima, Masanao Naya, Ai Shimizu, Yoshihiro Matsuno, Noriko Oyama-Manabe, Toshihisa Anzai
    Internal medicine (Tokyo, Japan) 58 (17) 2539 - 2543 2019/09/01 [Refereed][Not invited]
     
    Although cardiac involvement is rare in polyneuropathy, organomegaly, endocrinopathy, M protein, and skin changes (POEMS) syndrome, the clinical course becomes considerably worse on complication with cardiac lesions. The increased release of various cytokines has been observed in the pathogenesis of POEMS syndrome, and serum vascular endothelial growth factor (VEGF) levels are known to be associated with the disease activity. We herein report a patient with POEMS syndrome who showed left ventricular systolic dysfunction and was treated with lenalidmide therapy. Of note, the reduction in extracellular edema in the left ventricular wall was clearly visualized by changes in the native T1 values and extracellular volumes on cardiac magnetic resonance imaging.
  • Michito Murayama, Hiroyuki Iwano, Shingo Tsujinaga, Miwa Sarashina, Suguru Ishizaka, Yasuyuki Chiba, Masahiro Nakabachi, Shinobu Yokoyama, Hisao Nishino, Kazunori Okada, Sanae Kaga, Hitoshi Shibuya, Mutsumi Nishida, Toshihisa Anzai
    Echocardiography (Mount Kisco, N.Y.) 36 (9) 1771 - 1775 2019/09 [Refereed][Not invited]
     
    Although the presence and physiological significance of late-diastolic tricuspid regurgitation (TR) have been reported, those in TR occurring in early diastole have not been well known. We herein first presented a case of heart failure due to dilated cardiomyopathy showing functional TR occurring in the early-diastolic phase in whom the mechanism for its genesis could be precisely assessed from echocardiographic findings and intra-cardiac pressure recordings.
  • Hisao Nishino, Hiroyuki Iwano, Sanae Kaga, Mutsumi Nishida, Koji Akizawa, Takanori Teshima, Toshihisa Anzai
    Journal of echocardiography 2019/08/03 [Refereed][Not invited]
  • Kazunori Omote, Toshiyuki Nagai, Naoya Asakawa, Kiwamu Kamiya, Yusuke Tokuda, Tadao Aikawa, Arata Fukushima, Keiji Noguchi, Yoshiya Kato, Hirokazu Komoriyama, Mutsumi Nishida, Yusuke Kudo, Hiroyuki Iwano, Takashi Yokota, Toshihisa Anzai
    Heart and vessels 34 (6) 984 - 991 2019/06 [Refereed][Not invited]
     
    Liver stiffness (LS) has been reported to be a marker of liver congestion caused by elevated central venous pressure in heart failure (HF) patients. Recent studies demonstrated that LS could be non-invasively measured by virtual touch quantification (VTQ). However, its prognostic implication in patients with acute decompensated heart failure (ADHF) is unclear. This study sought to determine whether LS measured by VTQ could be a determinant of subsequent adverse events in ADHF patients. We prospectively recruited 70 ADHF patients who underwent LS measurement by VTQ on admission in our university hospital between June 2016 and April 2018. The primary outcome of interest was the composite of all-cause mortality and worsening HF. During a median follow-up period of 272 (interquartile range 122-578) days, there were 26 (37%) events, including 5 (7%) deaths and 21 (30%) cases of worsening HF. The c-index of LS for predicting the composite of adverse events was 0.77 (95% CI 0.66-0.88), and the optimal cut-off value of LS was 1.50 m/s. Adverse events were more frequently observed in patients with high LS (≥ 1.50 m/s) compared to those with low LS (< 1.50 m/s). Multivariable Cox regression analyzes revealed that higher LS was independently associated with increased subsequent risk of adverse events after adjustment for confounders. In conclusion, high admission LS was an independent determinant of worse clinical outcomes in patients with ADHF. This finding suggests that LS on admission is useful for risk stratification of patients with ADHF.
  • Shingo Tsujinaga, Hiroyuki Iwano, Miwa Sarashina, Taichi Hayashi, Michito Murayama, Ayako Ichikawa, Masahiro Nakabachi, Hisao Nishino, Shinobu Yokoyama, Arata Fukushima, Takashi Yokota, Kazunori Okada, Sanae Kaga, Pavlos P Vlachos, Toshihisa Anzai
    Journal of cardiac failure 25 (4) 268 - 277 2019/04 [Refereed][Not invited]
     
    BACKGROUND: Although the enhancement of early-diastolic intra-left ventricular pressure difference (IVPD) during exercise is considered to maintain exercise capacity, little is known about their relationship in heart failure (HF). METHODS AND RESULTS: Cardiopulmonary exercise testing and exercise-stress echocardiography were performed in 50 HF patients (left ventricular [LV] ejection fraction 39 ± 15%). Echocardiographic images were obtained at rest and submaximal and peak exercise. Color M-mode Doppler images of LV inflow were used to determine IVPD. Thirty-five patients had preserved exercise capacity (peak oxygen consumption [VO2] ≥14 mL·kg-1·min-1; group 1) and 15 patients had reduced exercise capacity (group 2). During exercise, IVPD increased only in group 1 (group 1: 1.9 ± 0.9 mm Hg at rest, 4.1 ± 2.0 mm Hg at submaximum, 4.7 ± 2.1 mm Hg at peak; group 2: 1.9 ± 0.8 mm Hg at rest, 2.1 ± 0.9 mm Hg at submaximum, 2.1 ± 0.9 mm Hg at peak). Submaximal IVPD (r = 0.54) and peak IVPD (r = 0.69) were significantly correlated with peak VO2. Peak IVPD determined peak VO2 independently of LV ejection fraction. Moreover, submaximal IVPD could well predict the reduced exercise capacity. CONCLUSION: Early-diastolic IVPD during exercise was closely associated with exercise capacity in HF. In addition, submaximal IVPD could be a useful predictor of exercise capacity without peak exercise in HF patients.
  • Michito Murayama, Hiroyuki Iwano, Yusuke Kudo, Mutsumi Nishida, Koji Akizawa, Hitoshi Shibuya, Toshihisa Anzai
    CASE (Philadelphia, Pa.) 2 (6) 248 - 253 2018/12 [Refereed][Not invited]
  • Hikaru Hagiwara, Arata Fukushima, Hiroyuki Iwano, Toshihisa Anzai
    European heart journal. Case reports 2 (4) yty100  2018/12 [Refereed][Not invited]
     
    Background: Drug rash with eosinophilia and systemic symptoms (DRESS) syndrome is a severe adverse drug reaction accompanied by multiple organ dysfunction. Myocarditis is a manifestation, and once acute necrotizing eosinophilic myocarditis (ANEM) develops, the mortality rate is high. Case summary: We report the case of a 37-year-old man who developed myocarditis associated with DRESS syndrome after starting treatment with lithium and quetiapine for bipolar disorder. At that time, he presented with fever, morbilliform eruption, lymphadenopathy, eosinophilia with atypical lymphocytes, and liver dysfunction; bipolar drugs were discontinued and oral prednisolone begun. Four months later, he was admitted to our institution with worsening skin rash and dyspnoea. Transthoracic echocardiography revealed reduced systolic function in both ventricles, and endocardial biopsy indicated hypersensitivity myocarditis. Cardiac function was temporarily normalized by high-dose prednisolone. However, the inflammation was persistent as shown by a re-elevation of troponin T and fall of left ventricular ejection fraction several months later; in addition, 18F-fluoro-deoxyglucose positron emission tomography with chest computed tomography (FDG-PET/CT) showed focal FDG uptake in the left ventricle. Despite additional treatment with mycophenolate mofetil, the cardiac function deteriorated further, and the patient eventually manifested refractory heart failure classified as New York Heart Association (NYHA) Class III. Myocardial biopsy showed myocyte necrosis associated with ANEM. Discussion: This is the first case report of DRESS-associated myocarditis due to treatment for bipolar disorder. Although the pathophysiology remains incompletely understood, lithium and/or quetiapine can induce refractory myocarditis in DRESS syndrome. Regular measurements of troponin T and FDG-PET/CT are useful for assessing disease progression in DRESS-associated myocarditis.
  • Yoshiya Kato, Arata Fukushima, Hiroyuki Iwano, Kiwamu Kamiya, Toshiyuki Nagai, Toshihisa Anzai
    Journal of cardiology cases 18 (5) 175 - 179 2018/11 [Refereed][Not invited]
     
    Severe tricuspid regurgitation (TR) is reported to represent a hemodynamic pattern similar to that of constrictive pericarditis (CP), which should be clearly differentiated for appropriate management. We report the case of a patient with severe TR due to atrial fibrillation (AF) in whom hemodynamic monitoring played a role in the selection of the management strategy. An 81-year-old Japanese man with chronic AF was admitted due to worsening heart failure. Echocardiography showed the dilation of bilateral atria and a right ventricle with severe TR. The right heart catheterization demonstrated the elevation and equalization of diastolic pressures of four cardiac chambers with impaired diastolic filling pattern, which are hallmarks of pericardial constriction due to CP. Of note, the CP-like hemodynamics were completely normalized by 10 days of medical therapies including diuretics and carperitide. After his discharge and over a 1-year follow-up, he has never experienced worsening heart failure and remained NYHA class II with moderate TR. Medical management targeted at volume reduction and vasodilation can be a therapeutic option for CP-like hemodynamics in isolated severe TR related to AF. Repeated hemodynamic assessment is an appropriate tool to help our understanding of the CP-like physiology caused by severe TR based on chronic AF. .
  • Kazunori Okada, Sanae Kaga, Rika Abiko, Michito Murayama, Takuma Hioka, Masahiro Nakabachi, Shinobu Yokoyama, Hisao Nishino, Ayako Ichikawa, Ayumu Abe, Mutsumi Nishida, Naoya Asakawa, Shingo Tsujinaga, Taichi Hayashi, Hiroyuki Iwano, Satoshi Yamada, Nobuo Masauzi, Taisei Mikami
    European heart journal cardiovascular Imaging 19 (11) 1260 - 1267 2047-2404 2018/11/01 [Refereed][Not invited]
     
    Aims: The detection of increased left ventricular (LV) chamber stiffness may play an important role in assessing cardiac patients with potential but not overt heart failure. A non-invasive method to estimate it is not established. We investigated whether the echocardiographic backward/forward flow volume ratio from the left atrium (LA) during atrial contraction reflects the LV chamber stiffness. Methods and results: We studied 62 patients who underwent cardiac catheterization and measured their left ventricular end-diastolic pressure (LVEDP) and pressure increase during atrial contraction (ΔPa) from the LV pressure waveform. Using the echocardiographic biplane method of disks, we measured the LV volume change during atrial contraction indexed to the body surface area (ΔVa), and ΔPa/ΔVa was calculated as a standard for the LV operating chamber stiffness. Using pulsed Doppler echocardiography, we measured the time-velocity integral (TVI) of the backward pulmonary venous (PV) flow during atrial contraction (IPVA) and the ratio of IPVA to the PV flow TVI throughout a cardiac cycle (FPVA). We also measured the TVI of the atrial systolic forward transmitral flow (IA) and the ratio of the IA to the transmitral TVI during a cardiac cycle (FA) and calculated IPVA/IA and FPVA/FA. IPVA/IA and FPVA/FA were well correlated with ΔPa/ΔVa (r = 0.79 and r = 0.81) and LVEDP (r = 0.73 and r = 0.77). The areas under the ROC curve to discriminate LVEDP >18 mmHg were 0.90 for IPVA/IA and 0.93 for FPVA/FA. Conclusion: The FPVA/FA, the backward/forward flow volume ratio from the LA during atrial contraction, is useful for non-invasive assessments of LV chamber stiffness and elevated LVEDP.
  • Kenya Kusunose, Kentaro Shibayama, Hiroyuki Iwano, Masaki Izumo, Nobuyuki Kagiyama, Koji Kurosawa, Hirotsugu Mihara, Hiroki Oe, Tetsuari Onishi, Toshinari Onishi, Mitsuhiko Ota, Shunsuke Sasaki, Yumi Shiina, Hikaru Tsuruta, Hidekazu Tanaka, on behalf of the JAYEF Investigators
    Journal of Cardiology 72 (1) 74 - 80 1876-4738 2018/07/01 [Refereed][Not invited]
     
    Background: Visual estimation of left ventricular ejection fraction (LVEF) is widely applied to confirm quantitative EF. However, visual assessment is subjective, and variability may be influenced by observer experience. We hypothesized that a learning session might reduce the misclassification rate. Methods: Protocol 1: Visual LVEFs for 30 cases were measured by 79 readers from 13 cardiovascular tertiary care centers. Readers were divided into 3 groups by their experience: limited (1–5 years, n = 28), intermediate (6–11 years, n = 26), and highly experienced (12-years, n = 25). Protocol 2: All readers were randomized to assess the effect of a learning session with reference images only or feedback plus reference images. After the session, 20 new cases were shown to all readers following the same methodology. To assess the concordance and accuracy pre- and post-intervention, each visual LVEF measurement was compared to overall average values as a reference. Results: Experience affected the concordance in visual EF values among the readers. Groups with intermediate and high experience showed significantly better mean difference (MD), standard deviation (SD), and coefficient of variation (CV) than those with limited experience at baseline. The learning session with reference image reduced the MD, SD, and CV in readers with limited experience. The learning session with reference images plus feedback also reduced proportional bias. Importantly, the misclassification rate for mid-range EF cases was reduced regardless of experience. Conclusion: This large multicenter study suggested that a simple learning session with reference images can successfully reduce the misclassification rate for LVEF assessment.
  • Hiroyuki Iwano, Shingo Tsujinaga, Daiki Iwami, Naoya Asakawa, Satoshi Yamada, Toshihisa Anzai
    CASE (Philadelphia, Pa.) 2 (3) 103 - 108 2018/06 [Refereed][Not invited]
  • Masahiro Nakabachi, Satoshi Yamada, Hiroyuki Iwano, Taichi Hayashi, Kazunori Okada, Kenya Kusunose, Kiyotaka Watanabe, Tomoko Ishizu, Kazuaki Wakami, Hirotsugu Yamada, Kaoru Dohi, Yoshihiro Seo, Nobuyuki Ohte, Chikara Shimizu, Taisei Mikami
    Circulation Journal 82 (3) 732 - 738 1347-4820 2018 [Refereed][Not invited]
     
    Background: Early-diastolic mitral annular velocity (e′) and the ratio of early-diastolic left ventricular (LV) inflow velocity (E) to e′ (E/e′) have been widely used as indexes of LV relaxation and filling pressure, respectively. However, many recent studies have demonstrated that they are not reliable in various clinical settings. We thus investigated the factors influencing these echocardiographic parameters in a multicenter study. Methods and Results: The study group comprised 69 patients, referred for cardiac catheterization, and enrolled in 5 university hospitals. Time constant (τ) and LV mean diastolic pressure (LVMDP) were measured using a micromanometer-tipped catheter. Although e′ only weakly correlated with τ (r=−0.35, P< 0.01), E/e′ modestly correlated with LVMDP (r=0.48, P< 0.001). Multivariable analysis revealed that hypertension (β=−0.33, P< 0.01) and LV ejection fraction (LVEF) (β=0.44, P< 0.001) were the independent determinants of e′, and LV mass index (LVMI) (β=0.37, P< 0.001) and LVMDP (β=0.47, P< 0.001) were those of E/e′. Additionally, E/e′ significantly correlated with LVMDP in patients with normal LVMI (r=0.74, P< 0.001) but not in those with increased LVMI. Conclusions: The coincidence of hypertension and LVEF affected the relationship between LV relaxation and e′, whereas LVMI altered the relationship between LV filling pressure and E/e′. Thus, clinical conditions associated with an increase in LVMI, such as LV hypertrophy and LV dilatation, should be considered when estimating the filling pressure from E/e′.
  • Takeshi Umazume, Takahiro Yamada, Satoshi Yamada, Satoshi Ishikawa, Itsuko Furuta, Hiroyuki Iwano, Daisuke Murai, Taichi Hayashi, Kazunori Okada, Mamoru Morikawa, Takashi Yamada, Kota Ono, Hiroyuki Tsutsui, Hisanori Minakami
    Open heart 5 (2) e000850  2018 [Refereed][Not invited]
     
    Objective: This longitudinal study was performed to determine changes in echocardiography parameters in association with various biomarker levels in pregnancy/postpartum. Methods: Fifty-one healthy pregnant women underwent echocardiography with simultaneous determination of blood levels of five biomarkers at each of the first, second and third trimesters of pregnancy, immediately postpartum within 1 week after childbirth and approximately 1 month postpartum. Data on 255 echocardiography scans (five times per woman) and biomarkers were analysed. Results: Left ventricular end-diastolic dimension, left atrial (LA) volume index and left ventricular (LV) mass index increased with advancing gestation and reached the maximum immediately postpartum concomitant with the highest brain natriuretic peptide (BNP), N-terminal pro B-type natriuretic peptide (NT-proBNP), high-sensitivity troponin I (hs-TnI) and creatine kinase MB levels. The inferior vena cava diameter was significantly reduced in the third trimester compared with that in the first trimester and the peak occurred immediately after childbirth. In 255 paired measurements, hs-TnI level was significantly positively correlated with LA volume index and LV mass index; BNP and NT-proBNP were significantly positively correlated with LA volume index and estimated glomerular filtration rate (eGFR) was significantly positively correlated with the average of early diastolic septal and lateral mitral annular velocity (e'). Conclusions: Maximal cardiac changes in morphology occurred postpartum within 1 week after childbirth, not during pregnancy. BNP/NT-proBNP, hs-TnI and eGFR reflected cardiac changes in pregnancy.
  • Takeshi Umazume, Satoshi Yamada, Takahiro Yamada, Satoshi Ishikawa, Itsuko Furuta, Hiroyuki Iwano, Daisuke Murai, Taichi Hayashi, Kazunori Okada, Mamoru Morikawa, Hiroyuki Tsutsui, Hisanori Minakami
    Open heart 5 (2) e000829  2018 [Refereed][Not invited]
     
    Objective: Women with hypertensive disorders of pregnancy (HDP) show elevated risk of heart failure despite decreased circulating plasma volume compared with those with normotensive control pregnancies (NCP). This study was performed to better characterise the heart in women with HDP and determine whether high-sensitivity troponin I (hs-TnI) around childbirth predicts reduced left ventricular (LV) relaxation at 1 month postpartum. Methods: Echocardiography was performed longitudinally during the first, second and third trimesters and immediately postpartum within 1 week and 1 month postpartum in 24 women with HDP, with simultaneous determination of blood variables in comparison with 51 women with NCP. Results: Compared with NCP, HDP showed greater antepartum left atrial (LA) volume, LV mass and inferior vena cava (IVC) diameter, higher peripartum brain natriuretic peptide/N-terminal pro-B-type natriuretic peptide and hs-TnI with the highest value immediately postpartum, and lower early diastolic mitral annular velocity (e') during pregnancy/postpartum. In analyses of data on HDP and NCP, hs-TnI at the third trimester as well as that immediately postpartum was negatively correlated with later e' at 1 month postpartum. The areas under the receiver operating characteristic curves were 0.82 and 0.81 for hs-TnI at the third trimester and immediately postpartum, respectively, in the prediction of reduced LV relaxation at 1 month postpartum. Conclusion: Reduced LV diastolic function and decreased splanchnic blood reservoir may contribute to the increased third trimester IVC diameter and LA volume in women with HDP. The rise in hs-TnI around childbirth was associated with poor LV relaxation ability at 1 month postpartum.
  • Masahiro Nakabachi, Satoshi Yamada, Hiroyuki Iwano, Taichi Hayashi, Kazunori Okada, Kenya Kusunose, Kiyotaka Watanabe, Tomoko Ishizu, Kazuaki Wakami, Hirotsugu Yamada, Kaoru Dohi, Yoshihiro Seo, Nobuyuki Ohte, Chikara Shimizu, Taisei Mikami
    Circulation Journal 82 (3) 732 - 738 1347-4820 2018 [Refereed][Not invited]
     
    Background: Early-diastolic mitral annular velocity (e′) and the ratio of early-diastolic left ventricular (LV) inflow velocity (E) to e′ (E/e′) have been widely used as indexes of LV relaxation and filling pressure, respectively. However, many recent studies have demonstrated that they are not reliable in various clinical settings. We thus investigated the factors influencing these echocardiographic parameters in a multicenter study. Methods and Results: The study group comprised 69 patients, referred for cardiac catheterization, and enrolled in 5 university hospitals. Time constant (τ) and LV mean diastolic pressure (LVMDP) were measured using a micromanometer-tipped catheter. Although e′ only weakly correlated with τ (r=−0.35, P< 0.01), E/e′ modestly correlated with LVMDP (r=0.48, P< 0.001). Multivariable analysis revealed that hypertension (β=−0.33, P< 0.01) and LV ejection fraction (LVEF) (β=0.44, P< 0.001) were the independent determinants of e′, and LV mass index (LVMI) (β=0.37, P< 0.001) and LVMDP (β=0.47, P< 0.001) were those of E/e′. Additionally, E/e′ significantly correlated with LVMDP in patients with normal LVMI (r=0.74, P< 0.001) but not in those with increased LVMI. Conclusions: The coincidence of hypertension and LVEF affected the relationship between LV relaxation and e′, whereas LVMI altered the relationship between LV filling pressure and E/e′. Thus, clinical conditions associated with an increase in LVMI, such as LV hypertrophy and LV dilatation, should be considered when estimating the filling pressure from E/e′.
  • 心房細動に伴う心房拡大と高度三尖弁逆流によって収縮性心膜炎様の血行動態を呈した収縮能の保たれた心不全の一例
    加藤 喜哉, 福島 新, 表 和徳, 木村 銀河, 浅川 直也, 徳田 裕輔, 神谷 究, 岩野 弘幸
    日本心臓病学会学術集会抄録 (一社)日本心臓病学会 65回 P - 219 2017/09 [Refereed][Not invited]
  • Takuma Hioka, Sanae Kaga, Taisei Mikami, Kazunori Okada, Michito Murayama, Nobuo Masauzi, Masahiro Nakabachi, Hisao Nishino, Shinobu Yokoyama, Mutsumi Nishida, Hiroyuki Iwano, Mamoru Sakakibara, Satoshi Yamada, Hiroyuki Tsutsui
    HEART AND VESSELS 32 (7) 833 - 842 0910-8327 2017/07 [Refereed][Not invited]
     
    We investigated the influence of tricuspid regurgitation (TR) severity on the echocardiographic peak systolic transtricuspid pressure gradient (TRPG) and evaluated the usefulness of the peak early diastolic transpulmonary valve pressure gradient (PRPG) for estimating pulmonary artery (PA) pressure. In 55 consecutive right heart-catheterized patients, we measured the peak systolic right ventricular (RV)-right atrial (RA) pressure gradient (RV-RA(CATH)), peak early diastolic PA-RV pressure gradient (PA-RVCATH), and mean PA pressure (MPAP(CATH)). Using echocardiography, we obtained the TRPG, PRPG, and an estimate of the mean PA pressure (EMPAP) as the sum of PRPG and the estimated RA pressure, and measured the vena contracta width of TR (VCTR). The difference between the TRPG and RV-RA(CATH) was significantly greater in the very severe TR group (VCTR > 11 mm) than in the mild, moderate, and severe TR groups, and significantly greater in the severe TR group (7 < VCTR ae<currency> 11 mm) than in the mild TR group. The overestimation of the pressure gradient > 10 mmHg by TRPG was not seen in the mild or moderate TR groups, but was observed in the severe and very severe TR groups (22 and 83%, respectively). In the ROC analysis, EMPAP could distinguish patients with MPAP(CATH) ae<yen> 25 mmHg with the area under the curve of 0.93, 100% sensitivity, and 87% specificity. In conclusion, TRPG frequently overestimated RV-RA(CATH) when VCTR was > 11 mm and sometimes did when VCTR was > 7 mm, where EMPAP using PRPG was useful for estimating PA pressure.
  • Daisuke Murai, Satoshi Yamada, Taichi Hayashi, Kazunori Okada, Hisao Nishino, Masahiro Nakabachi, Shinobu Yokoyama, Ayumu Abe, Ayako Ichikawa, Kota Ono, Sanae Kaga, Hiroyuki Iwano, Taisei Mikami, Hiroyuki Tsutsui
    HEART AND VESSELS 32 (5) 574 - 583 0910-8327 2017/05 [Refereed][Not invited]
     
    Whether and how left ventricular (LV) strain and strain rate correlate with wall stress is not known. Furthermore, it is not determined whether strain or strain rate is less dependent on the afterload. In 41 healthy young adults, LV global peak strain and systolic peak strain rate in the longitudinal direction (LS and LSR, respectively) and circumferential direction (CS and CSR, respectively) were measured layer-specifically using speckle tracking echocardiography (STE) before and during a handgrip exercise. Among all the points before and during the exercise, all the STE parameters significantly correlated linearly with wall stress (LS: r = -0.53, p < 0.01, LSR: r = -0.28, p < 0.05, CS in the inner layer: r = -0.72, p < 0.01, CSR in the inner layer: r = -0.47, p < 0.01). Strain more strongly correlated with wall stress than strain rate (r = -0.53 for LS vs. r = -0.28 for LSR, p < 0.05; r = -0.72 for CS vs. r = -0.47 for CSR in the inner layer, p < 0.05), whereas the interobserver variability was similar between strain and strain rate (longitudinal 6.2 vs. 5.2 %, inner circumferential 4.8 vs. 4.7 %, mid-circumferential 7.9 vs. 6.9 %, outer circumferential 10.4 vs. 9.7 %), indicating that the differences in correlation coefficients reflect those in afterload dependency. It was thus concluded that LV strain and strain rate linearly and inversely correlated with wall stress in the longitudinal and circumferential directions, and strain more strongly depended on afterload than did strain rate. Myocardial shortening should be evaluated based on the relationships between these parameters and wall stress.
  • Kazunori Okada, Sanae Kaga, Taisei Mikami, Nobuo Masauzi, Ayumu Abe, Masahiro Nakabachi, Shinobu Yokoyama, Hisao Nishino, Ayako Ichikawa, Mutsumi Nishida, Daisuke Murai, Taichi Hayashi, Chikara Shimizu, Hiroyuki Iwano, Satoshi Yamada, Hiroyuki Tsutsui
    HEART AND VESSELS 32 (5) 591 - 599 0910-8327 2017/05 [Refereed][Not invited]
     
    We analyzed the waveform of systolic strain and strain-rate curves to find a characteristic left ventricular (LV) myocardial contraction pattern in patients with hypertrophic cardiomyopathy (HCM), and evaluated the utility of these parameters for the differentiation of HCM and LV hypertrophy secondary to hypertension (HT). From global strain and strain-rate curves in the longitudinal and circumferential directions, the time from mitral valve closure to the peak strains (T-LS and T-CS, respectively) and the peak systolic strain rates (T-LSSR and T-CSSR, respectively) were measured in 34 patients with HCM, 30 patients with HT, and 25 control subjects. The systolic strain-rate waveform was classified into 3 patterns ("V", "W", and "root" pattern). In the HCM group, T-LS was prolonged, but T-LSSR was shortened; consequently, T-LSSR/TLS ratio was distinctly lower than in the HT and control groups. The "root" pattern of longitudinal strain-rate waveform was more frequently seen in the HCM group (74 %) than in the control (4 %) and HT (20 %) groups. Similar but less distinct results were obtained in the circumferential direction. To differentiate HCM from HT, the sensitivity and specificity of the T-LSSR/TLS ratio <0.34 and the "root"-shaped longitudinal strain-rate waveform were 85 and 63 %, and 74 and 80 %, respectively. In conclusion, in patients with HCM, a reduced T-LSSR/T-LS ratio and a characteristic "root"- shaped waveform of LV systolic strain rate was seen, especially in the longitudinal direction. The timing and waveform analyses of systolic strain rate may be useful to distinguish between HCM and HT.
  • Michito Murayama, Taisei Mikami, Sanae Kaga, Kazunori Okada, Takuma Hioka, Nobuo Masauzi, Masahiro Nakabachi, Hisao Nishino, Shinobu Yokoyama, Mutsumi Nishida, Hiroyuki Iwano, Mamoru Sakakibara, Satoshi Yamada, Hiroyuki Tsutsui
    ULTRASOUND IN MEDICINE AND BIOLOGY 43 (5) 958 - 966 0301-5629 2017/05 [Refereed][Not invited]
     
    In our new echocardiographic method, pulmonary regurgitant velocity immediately before right atrial (RA) contraction is used to estimate pulmonary artery diastolic pressure (PADP) and mean PA wedge pressure (MPAWP). Our aim here was to compare the usefulness of this new method with that of the conventional method, which uses pulmonary regurgitant velocity at end diastole. We studied 55 consecutive patients who underwent echocardiography and right-sided heart catheterization. The pulmonary regurgitant velocities just before RA contraction and at end diastole were measured to obtain echocardiographic estimates of PADP (EPADP(preA) and EPADP(ED), respectively) by adding the pressure gradients to the echocardiographically estimated RA pressure. Compared with EPADP(ED), EPADP(preA) correlated better with PADP (r = 0.87) and MPAWP (r = 0.80), and direct fixed biases were detected for EPADP(ED) but not for EPADP(preA). The area under the receiver operating characteristic curve distinguishing patients with MPAWP > 18 mm Hg was greater for EPADP(preA) (0.97) than for E/e' (0.94) and E/A (0.83). EPADP(preA) is thus useful in estimating PADP and MPAWP in patients with heart disease. (C) 2017 World Federation for Ultrasound in Medicine & Biology.
  • Sanae Kaga, Taisei Mikami, Michito Murayama, Kazunori Okada, Nobuo Masauzi, Masahiro Nakabachi, Hisao Nishino, Shinobu Yokoyama, Mutsumi Nishida, Taichi Hayashi, Daisuke Murai, Hiroyuki Iwano, Mamoru Sakakibara, Satoshi Yamada, Hiroyuki Tsutsui
    INTERNATIONAL JOURNAL OF CARDIOVASCULAR IMAGING 33 (1) 31 - 38 1569-5794 2017/01 [Refereed][Not invited]
     
    Pulmonary vascular resistance (PVR) is an important hemodynamic parameter in patients with heart failure, especially when the pulmonary arterial pressure is lower due to reduced stroke volume. Several echocardiographic methods to estimate PVR have been proposed, but their applications in patients with organic left-sided heart diseases have been limited. The aim of the present study was to examine the usefulness of our new method to estimate PVR (PVRPR) based on the continuous-wave Doppler velocity measurements of pulmonary regurgitation in these patients. In 43 patients who underwent right heart catheterization, PVRPR was calculated as the difference between the Doppler-derived early- and end-diastolic pulmonary artery (PA)-right ventricular (RV) pressure gradients divided by the cardiac output measured in the left ventricular outflow tract by echocardiography. The PVRPR correlated well with invasive PVR (PVRCATH) (r = 0.81, p < 0.001) without any fixed bias in Bland-Altman analysis. The conventional echocardiographic PVRs showed inadequate correlations with PVRCATH, or a obvious overestimation of PVRCATH. In the receiver operating characteristic analyses to determine the patients with abnormal elevation of PVRCATH (> 3 Wood units, WU), the area under the curve was the greatest for PVRPR (0.964) compared to the conventional PVRs (0.649-0.839). PVRPR had 83 % sensitivity and 100 % specificity at the optimal cut-off value of 3.10 WU in identifying patients with PVRCATH > 3 WU. Our simple and theoretical PVRPR is useful for the noninvasive estimation of PVR.
  • Hiroyuki Iwano, Daisuke Kammura, Ervin R. Fox, Michael E. Hall, Pavlos Vlachos, William C. Little
    JOURNAL OF CARDIAC FAILURE 22 (12) 945 - 953 1071-9164 2016/12 [Refereed][Not invited]
     
    Background: Early-diastolic left ventricular (LV) longitudinal expansion is delayed with diastolic dysfunction. We hypothesized that, in patients with heart failure (HF), regardless of LV ejection fraction (EF), there is diastolic temporal nonuniformity with a delay of longitudinal relative to circumferential expansion. Methods and Results: Echocardiography was performed in 143 HF patients-50 with preserved EF (HFpEF) and 93 with reduced EF (HFrEF)-as well as 31 normal control subjects. The delay of early-diastolic mitral annular velocity from the mitral Doppler E (TE-e ') was measured as a parameter of the longitudinal expansion delay. The delay of the longitudinal early-diastolic global strain rate (SRE) relative to circumferential SRE (Delay(C-L)) was calculated as a parameter of temporal nonuniformity. Intra-LV pressure difference (IVPD) was estimated with the use of color M-mode Doppler data as a parameter of LV diastolic suction. Although normal control subjects had symmetric LV expansion in early diastole, TE-e ' and Delay(C-L) were significantly prolonged in HF regardless of EF (P <.01 vs control for all). Multivariate analysis revealed that Delay(C-L) was the independent determinant of IVPD among the parameters of LV geometry and contraction (beta = -0.21; P < .05). Conclusion: An abnormal temporal nonuniformity of early-diastolic expansion is present in HF regardless of EF, which was associated with reduced LV suction.
  • Atsuro Masuda, Keiichiro Yoshinaga, Masanao Naya, Osamu Manabe, Satoshi Yamada, Hiroyuki Iwano, Tatsuya Okada, Chietsugu Katoh, Yasuchika Takeishi, Hiroyuki Tsutsui, Nagara Tamaki
    EJNMMI research 6 (1) 41 - 41 2016/12 [Refereed][Not invited]
     
    BACKGROUND: Accelerated clearance of (99m)technetium-sestamibi (MIBI) has been observed after reperfusion therapy in patients with acute coronary syndrome (ACS), but the mechanisms have not been fully investigated. MIBI retention may depend on mitochondrial function. The clearance rate of (11)carbon-acetate reflects such mitochondrial functions as oxidative metabolism. The purpose of this study was to examine the mechanisms of accelerated MIBI clearance in ACS. We therefore compared it to oxidative metabolism estimated using (11)C-acetate positron emission tomography (PET). METHODS: Eighteen patients [mean age 69.2 ± 8.7 years, 10 males (56 %)] with reperfused ACS underwent MIBI single-photon emission computed tomography (SPECT), echocardiography, and (11)C-acetate PET within 3 weeks of the onset of ACS. MIBI images were obtained 30 min and 3 h after MIBI administration. Regional left ventricular (LV) function was evaluated by echocardiography. The measurement of oxidative metabolism was obtained through the mono-exponential fitting of the (11)C-acetate time-activity curve (k mono). RESULTS: Among 95 segments of reperfused myocardium, MIBI SPECT showed 64 normal segments (group N), 14 segments with accelerated MIBI clearance (group AC), and 17 segments with fixed defect (group F). Group AC showed lower k mono than group N (0.041 ± 0.009 vs 0.049 ± 0.010, p = 0.02). Group F showed lower k mono than group N (0.039 ± 0.012 vs 0.049 ± 0.010, p = 0.01). However, k mono was similar in group AC and group F (p = 0.99). CONCLUSIONS: Segments with accelerated MIBI clearance showed reduced oxidative metabolism in ACS. Loss of MIBI retention may be associated with mitochondrial dysfunction.
  • Hiroyuki Iwano, Satoshi Yamada, Kazunori Okada, Taichi Hayashi, Shingo Tsujinaga, Shinobu Yokoyama, Masahiro Nakabachi, Hisao Nishino, Ayako Ichikawa, Ayumu Abe, Sanae Kaga, Taisei Mikami, Hiroyuki Tsutsui
    CIRCULATION 134 0009-7322 2016/11 [Refereed][Not invited]
  • Shinobu Yokoyama, Hiroyuki Iwano, Satoshi Yamada, Mahito Takeda, Sanae Kaga, Masahiro Nakabachi, Hisao Nishino, Ayako Ichikawa, Ayumu Abe, Kazunori Okada, Daisuke Murai, Taichi Hayashi, Mutsumi Nishida, Hitoshi Shibuya, Kaoru Kahata, Chikara Shimizu, Taisei Mikami, Hiroyuki Tsutsui
    Journal of Cardiology Cases 14 (3) 82 - 86 1878-5409 2016/09/01 [Refereed][Not invited]
     
    Nonbacterial thrombotic endocarditis (NBTE) is characterized by the deposition of thrombi on previously undamaged heart valves in the absence of bacteremia and predominantly affects patients with hypercoagulable state. Although the diagnosis is usually based on transthoracic echocardiography, little is known about the serial changes of the vegetation in response to treatment. We experienced a 42-year-old woman with advanced uterine cancer and asymptomatic cerebral embolization. Plasma D-dimer level was markedly elevated and echocardiography showed highly mobile masses attached to the anterior and posterior mitral leaflets with moderate regurgitation. Based on these findings, she was diagnosed as having NBTE associated with uterine cancer and intravenous administration of heparin and chemotherapy were performed. Follow-up echocardiography revealed the disappearance of the vegetation and reduction of mitral regurgitation. Uterine cancer was successfully treated by surgery and recurrence of the valvular lesion did not occur. < Learning objective: Echocardiographic follow-up of valvular lesions could be a useful guide of the response to the treatment in patients with nonbacterial thrombotic endocarditis. Accordingly, anticoagulation therapy with careful follow-up echocardiography before the removal of the original cancer could be a reasonable approach in these patients.>
  • Taichi Hayashi, Satoshi Yamada, Hiroyuki Iwano, Masahiro Nakabachi, Mamoru Sakakibara, Kazunori Okada, Daisuke Murai, Hisao Nishino, Kenya Kusunose, Kiyotaka Watanabe, Tomoko Ishizu, Kazuaki Wakami, Hirotsugu Yamada, Kaoru Dohi, Yoshihiro Seo, Nobuyuki Ohte, Taisei Mikami, Hiroyuki Tsutsui
    CIRCULATION JOURNAL 80 (5) 1163 - 1170 1346-9843 2016/05 [Refereed][Not invited]
     
    Background: Speckle-tracking echocardiography (STE)-derived parameters may have better correlation with left ventricular (LV) relaxation and filling pressure than tissue Doppler-derived parameters. However, it has not been elucidated which parameter - strain or strain rate - and which direction of myocardial deformation - longitudinal or circumferential - is the most useful marker of LV relaxation and filling pressure. Methods and Results: We conducted a prospective multicenter study and compared the correlation of tissue Doppler-and STE-derived parameters with the time constant of LV pressure decay (tau) and LV mean diastolic pressure (MDP) in 77 patients. The correlation of early-diastolic mitral annular velocity (e') with t was weak (r=-0.32, P<0.01), and that of peak longitudinal strain (LS) was the strongest (r=-0.45, P<0.001) among the STE-derived parameters. There was a modest correlation between LVMDP and the ratio of early-diastolic inflow velocity (E) to e' (E/e') (r=0.50, P<0.001). In contrast, the ratio of E to LS (E/LS) correlated strongly with LVMDP (r=0.70, P<0.001). The correlation of E/LS with LVMDP was significantly better than that for E/e' (P<0.01). Receiver-operating characteristic analysis showed that E/LS had the largest area under the curve for distinguishing elevated LVMDP (E/LS 0.86, E/e' 0.74, E/A 0.67). Conclusions: STE-derived longitudinal parameters correlated well with LV relaxation and filling pressure. In particular, E/LS could be more accurate than E/e' for estimating LV filling pressure.
  • Takashi Yoshitani, Naoya Asakawa, Mamoru Sakakibara, Keiji Noguchi, Yusuke Tokuda, Kiwamu Kamiya, Hiroyuki Iwano, Satoshi Yamada, Yusuke Kudou, Mutsumi Nishida, Chikara Shimizu, Toraji Amano, Hiroyuki Tsutsui
    CIRCULATION JOURNAL 80 (5) 1187 - + 1346-9843 2016/05 [Refereed][Not invited]
     
    Background: Heart failure (HF) causes organ congestion, which is thought to increase organ stiffness. The virtual touch quantification (VTQ) method can be used to assess liver stiffness in patients with chronic liver diseases. This study aimed to measure liver and kidney stiffness using VTQ and to determine its value for assessing organ congestion in patients with HF. Methods and Results: This study included 10 normal subjects and 38 HF patients (age 52.3 +/- 16.7 years, left ventricular ejection fraction 27.0 +/- 9.4%, plasma B-type natriuretic peptide [BNP] 1,297.3 +/- 1,155.1 pg/ml). We investigated the relationships between clinical characteristics and hemodynamics and liver and kidney stiffness, and assessed the effects of medical treatment on these measurements. Liver stiffness was significantly higher in HF patients (1.17 +/- 0.13 m/s vs. 2.03 +/- 0.91 m/s, P=0.004) compared with normal subjects, but kidney stiffness was similar in both groups. Central venous pressure (CVP) (P=0.021) and BNP (P=0.025) were independent predictive factors for increased liver stiffness in HF patients. Liver stiffness decreased significantly from 2.37 +/- 1.09 to 1.27 +/- 0.33 m/s (P<0.001) after treatment. Changes in liver stiffness in HF patients significantly correlated with changes in CVP (R=0.636, P=0.014) and cardiac index (R=-0.557, P=0.039) according to univariate analysis, and with changes in CVP in multivariate analysis. Conclusions: Liver stiffness measured by noninvasive VTQ methods can be used to assess liver congestion and therapeutic effects in patients with HF.
  • Kazunori Okada, Satoshi Yamada, Hiroyuki Iwano, Hisao Nishino, Masahiro Nakabachi, Shinobu Yokoyama, Ayumu Abe, Ayako Ichikawa, Sanae Kaga, Mutsumi Nishida, Taichi Hayashi, Daisuke Murai, Taisei Mikami, Hiroyuki Tsutsui
    CIRCULATION JOURNAL 79 (11) 2471 - 2479 1346-9843 2015/11 [Refereed][Not invited]
     
    Background: Although longitudinal strain (LS) is known to be reduced in patients with hypertrophic cardiomyopathy (HCM), it has not been elucidated whether or not circumferential strain (CS) is reduced. We aimed to determine whether multidirectional and layer-specific myocardial strain is reduced in patients with nonobstructive HCM. Methods and Results: Speckle-tracking echocardiography was performed in 41 HCM patients and 27 control subjects. Segmental and global LS and CS were measured in the inner, mid, and outer layers. Global LS was significantly lower in the HCM group than in controls in the inner (-10.3 +/- 2.9 vs. -14.8 +/- 2.0%, P<0.001), mid (-8.7 +/- 2.6 vs. -13.8 +/- 1.9%, P<0.001), and outer (-7.2 +/- 2.6 vs. -11.9 +/- 1.9%, P<0.001) layers. Global CS was preserved in the inner layer (-23.8 +/- 4.7 vs. -24.3 +/- 3.3%, P=0.69) but reduced in the mid (-10.3 +/- 3.1 vs. -13.3 +/- 2.5%, P<0.001) and outer layers (-6.7 +/- 2.3 vs. -8.6 +/- 2.3%, P=0.002). Differences in CS between the inner and outer layers correlated with segmental relative wall thickness (r=-0.20, P=0.002). Furthermore, only the absolute value of global CS in the inner layer positively correlated with left ventricular ejection fraction (r=0.32, P<0.01) among these multidirectional and layer-specific strains. Conclusions: In patients with HCM, not only the LS in all layers but also CS in the mid and outer layers was reduced, presumably reflecting impaired myocardial function. In contrast, CS in the inner layer was preserved, being associated with maintenance of chamber function.
  • Takahiro Ohara, Hiroyuki Iwano, Vinay Thohan, Dalane W. Kitzman, Bharathi Upadhya, Min Pu, William C. Little
    JOURNAL OF THE AMERICAN SOCIETY OF ECHOCARDIOGRAPHY 28 (10) 1184 - 1193 0894-7317 2015/10 [Refereed][Not invited]
     
    Background: Some patients with markedly reduced ejection fractions (EFs) (<35%) have preserved exercise performance greater than predicted for age and gender. Because diastolic function may be a determinant of exercise performance, this study was conducted to test the hypothesis that patients with preserved exercise tolerance despite EFs <35% may have relatively normal diastolic function. Methods: Sixty-five subjects with EFs <35% who underwent exercise Doppler echocardiography and had no inducible ischemia were retrospectively examined. Forty-five subjects with normal EFs (>60%) and preserved exercise capacity were analyzed as a control group. Results: Sixteen of 65 patients with EFs <35% had greater than predicted normal exercise capacity for their age and gender, and the remaining 49 patients had reduced exercise capacity. Patients with reduced EFs and preserved exercise capacity had E/e' ratios (mean, 10 6 4) similar to those of control subjects (mean, 10 6 3) and lower than those with reduced exercise tolerance (mean, 16 6 8) (P < .01). In addition, they had better diastolic filling patterns and smaller left atrial sizes than patients with EFs <35% and reduced exercise capacity. Multivariate logistic regression analyses indicated that E/e' ratio was an independent predictor of preserved exercise capacity in patients with reduced EFs. Conclusions: Relatively intact diastolic function contributes to preserved exercise capacity in patients with reduced EFs (<35%).
  • Hiroyuki Iwano, Daisuke Kamimura, Ervin Fox, Michael Hall, Pavlos Vlachos, William C. Little
    JOURNAL OF THE AMERICAN SOCIETY OF ECHOCARDIOGRAPHY 28 (5) 597 - U185 0894-7317 2015/05 [Refereed][Not invited]
     
    Background: The left ventricle fills in early diastole because of a progressive intraventricular pressure difference (IVPD) that extends from the left atrium to the left ventricular (LV). The aim of this study was to test the hypothesis that in patients with symptomatic heart failure (HF) regardless of LV ejection fraction (EF), an increase in left atrial (LA) pressure maintains early diastolic filling because of a preserved IVPD from the left atrium to the mid left ventricle, while the IVPD from the mid left ventricle to the apex is diminished because of reduced LV suction. Methods: One hundred fifty-one patients with HF (50 with HF with preserved EF [HFpEF; EF >= 50%] and 101 with HF with reduced EF [HFrEF; EF < 50%]) and 28 normal controls were prospectively enrolled. The IVPDs from the left atrium to the LV apex (total IVPD), the left atrium to the mid left ventricle (basilar IVPD), and the mid left ventricle to the apex (apical IVPD) were determined using color M-mode Doppler echocardiographic data to integrate the Euler equation. The propagation of early diastolic filling was also assessed by color M-mode Doppler. Results: The mean LV EF was 0.63 +/- 0.07 in patients with HFpEF, 0.32 +/- 0.09 in those with HFrEF, and 0.64 +/- 0.06 in controls. Peak early diastolic transmitral flow velocities (E) were similar among the groups, and basilar IVPDs were maintained in the HFpEF and HFrEF groups (HFpEF, 1.59 +/- 0.62 mm Hg; HFrEF, 1.49 +/- 0.75 mm Hg; controls, 1.80 +/- 0.61 mm Hg; P = NS, analysis of variance). However, apical IVPDs were decreased in both HF groups (HFpEF, 1.18 +/- 0.56 mm Hg [P < .01 vs controls]; HFrEF, 0.87 +/- 0.48 mm Hg [P < .01 vs controls]; controls, 1.65 +/- 0.62 mm Hg), resulting in decreased total IVPDs in patients with HF (HFpEF, 2.55 +/- 0.80 mm Hg [P < .01 vs controls]; HFrEF, 2.16 +/- 0.80 mm Hg [P < .01 vs controls]; controls, 3.17 +/- 0.91 mm Hg). E/e' ratios were increased in patients with HF, consistent with elevated LA pressure. In patients with HF, E was correlated with basilar IVPD but not with apical IVPD, whereas propagation of the filling was correlated with the apical IVPD but not with the basilar IVPD. Conclusions: In patients with HFpEF and those with HFrEF, apical IVPDs were reduced while basilar IVPDs were maintained by elevated LA pressure, resulting in preserved E.
  • Sanae Kaga, Taisei Mikami, Yuka Takamatsu, Ayumu Abe, Kazunori Okada, Masahiro Nakabachi, Hisao Nishino, Shinobu Yokoyama, Mutsumi Nishida, Chikara Shimizu, Hiroyuki Iwano, Satoshi Yamada, Hiroyuki Tsutsui
    JOURNAL OF THE AMERICAN SOCIETY OF ECHOCARDIOGRAPHY 27 (11) 1223 - 1229 0894-7317 2014/11 [Refereed][Not invited]
     
    Background: Many echocardiographic features of constrictive pericarditis (CP) have been reported, but each alone has a limitation either in sensitivity or in specificity. Continuous-wave Doppler-derived flow velocity of pulmonary regurgitation can reflect the diastolic right ventricular pressure pattern characteristic of CP and be useful for its detection. Methods: Fifteen patients with CP, 18 patients with restrictive cardiomyopathy, and 20 normal subjects were studied retrospectively. Using continuous-wave Doppler echocardiography, pulmonary regurgitation velocities were measured at the early diastolic peak (V-MAx), mid-diastolic inflection point (V-IFL), and late diastolic minimal point (V-MIN). Results: V-IFL, V-IFL/V-MAx, V-MIN, and V-MIN/V-MAx were significantly lower in the CP group compared with the restrictive cardiomyopathy and normal groups. Prevalence rates of patients with early mid-diastolic inflection, V-IFL/V-MAx < 0.5, V-MIN < 50 cm/sec, and V-MIN/V-MAx < 0.33 were significantly greater in the CP group compared with the other groups. Sensitivity and specificity for the diagnosis of CP were 93% and 74%, respectively, for the presence of early mid-diastolic inflection, 73% and 100% for V-IFL/V-MAx < 0.5, 73% and 97% for V-MIN < 50 cm/sec, and 93% and 92% for V-MIN/V-MAx < 0.33. Conclusions: The quantitative and pattern analyses of continuous-wave Doppler-derived pulmonary regurgitation velocity could enhance the accuracy of echocardiographic detection of CP.
  • Kazunori Okada, Taisei Mikami, Sanae Kaga, Masahiro Nakabachi, Ayumu Abe, Shinobu Yokoyama, Hisao Nishino, Mutsumi Nishida, Chikara Shimizu, Hiroyuki Iwano, Satoshi Yamada, Hiroyuki Tsutsui
    JOURNAL OF CLINICAL ULTRASOUND 42 (6) 341 - 347 0091-2751 2014/07 [Refereed][Not invited]
     
    Background. Left ventricular (LV) diastolic dysfunction is often observed in healthy older subjects without structural heart disease, although its exact mechanisms have not been established. A decrease in the aorto-septal angle (ASA), an alteration of LV shape due to aortic elongation, is also frequently seen in elderly subjects. The objective of this study was to evaluate whether it can contribute to LV diastolic dysfunction in healthy subjects. Methods. Echocardiography was performed in 77 healthy subjects (42 men, mean age 43.2 +/- 13.8 years) to measure the ASA, early diastolic transmitral flow velocity (E), isovolumic relaxation time (IRT), and early diastolic mitral annular velocity (e'). The LV peak early diastolic longitudinal strain rate (GSR(E)) was measured using a two-dimensional speckle tracking imaging technique. Results. ASA was significantly correlated with E (r=0.54, p<0.001), IRT (r=-0.41, p<0.001), e' (r=0.57, p<0.001), and GSRE (r=0.63, p<0.001) and shown by stepwise multivariate analysis to be the strongest independent determinant of E, IRT, and GSRE, and one of the independent determinants of e'. Conclusions. The alteration of LV shape associated with reduced ASA may be one of the causes of LV diastolic dysfunction independently of age in otherwise healthy subjects. (C) 2014 Wiley Periodicals, Inc.
  • Iwano H, Pu M, Upadhya B, Meyers B, Vlachos P, Little WC
    Physiological reports 2 (7) 2014/07 [Refereed][Not invited]
  • Kiwamu Kamiya, Mamoru Sakakibara, Naoya Asakawa, Shiro Yamada, Takashi Yoshitani, Hiroyuki Iwano, Hiroshi Komatsu, Masanao Naya, Satoru Chiba, Satoshi Yamada, Osamu Manabe, Yasuka Kikuchi, Noriko Oyama-Manabe, Koji Oba, Hiroyuki Tsutsui
    Circulation journal : official journal of the Japanese Circulation Society 78 (10) 2468 - 76 1346-9843 2014 [Refereed][Not invited]
     
    BACKGROUND: Fractional flow reserve (FFR) measured on catheterization is now widely used for the diagnosis of functional myocardial ischemia in patients with coronary artery disease (CAD). FFR, however, is invasive and carries potential procedural complications. Therefore, the aim of this study was to compare the diagnostic capability in functionally significant stenosis identified on FFR, between cardiac magnetic resonance myocardial perfusion imaging (CMR-MPI), single-photon emission computed tomography MPI (SPECT-MPI), and dobutamine stress echocardiography (DSE) in patients with CAD. METHODS AND RESULTS: A total of 25 patients who had at least 1 angiographic stenosis ≥50% on coronary angiography was studied. CMR-MPI, SPECT-MPI and DSE were done before FFR measurement. FFR was measured in all 3 major epicardial coronary arteries. Out of 71 vascular territories excluding 4 territories due to inadequate imaging, 29 (41%) had FFR <0.80. The sensitivity of CMR-MPI was significantly higher than that of SPECT-MPI and DSE (P=0.02 and P=0.001, respectively). The area under the receiver operating characteristic curve (AUC) for CMR-MPI (AUC, 0.92) was significantly greater than for SPECT-MPI (AUC, 0.73; P=0.006) and DSE (AUC, 0.69; P<0.001). CONCLUSIONS: CMR-MPI performed well in the detection of functionally significant stenosis defined according to FFR, and had the highest diagnostic sensitivity among the 3 modalities tested in patients with CAD.
  • Iwano H, Little WC
    Journal of cardiology 62 (1) 1 - 3 0914-5087 2013/07 [Refereed][Not invited]
  • Ayumu Abe, Taisei Mikami, Sanae Kaga, Kanako Tsuji, Kazunori Okada, Shinobu Yokoyama, Hisao Nishino, Masahiro Nakabachi, Mutsumi Nishida, Chikara Shimizu, Hiroyuki Iwano, Satoshi Yamada, Hiroyuki Tsutsui
    Journal of Echocardiography 11 (2) 41 - 49 1349-0222 2013/06 [Refereed][Not invited]
     
    Background: Assessing left ventricular (LV) hypertrophy (LVH) is an important step in the echocardiographic diagnosis of aortic stenosis (AS). We aimed to investigate the causes of discrepancies between the degrees of AS and LVH. Methods: The study subjects consisted of 149 consecutive patients with AS having aortic valve area < 2.0 cm2 (mean age 72.5 ± 11.9 years, 67 men and 82 women). Coexisting cardiac diseases were determined based on echocardiographic findings and comprehensive clinical judgment. Echocardiographic measurements included LV mass index (LVMI), aortic valve area index (AVAI), transaortic mean pressure gradient (MPG), valvulo-arterial impedance (Zva), energy loss coefficient (ELCo), and energy loss index (ELI). Results: LVMI was not significantly correlated with AVAI and Zva, and had a weak correlation with MPG (r = 0.305, p = 0.0001). There were 55 patients in group A (non-severe AS without significant LVH), 58 in group B (non-severe AS with significant LVH), 7 in group C (severe AS without significant LVH), and 29 in group D (severe AS with significant LVH). Coexisting cardiac diseases were more frequently observed (p = 0.0003) in group B (50 %) than in group A (18 %). In group C, ELCo and (ELI - AVAI)/ELI were significantly greater than in group D (p = 0.043 and 0.007, respectively). Conclusion: Significant LVH seen in less than moderate AS is often due to coexisting cardiac diseases, and there may be an overestimation of AS severity due to pressure recovery among patients with apparently severe AS who do not have significant LVH. © 2013 Japanese Society of Echocardiography.
  • Satoru Chiba, Masanao Naya, Hiroyuki Iwano, Keiichiro Yoshinaga, Chietsugu Katoh, Osamu Manabe, Satoshi Yamada, Satoru Wakasa, Suguru Kubota, Yoshiro Matsui, Nagara Tamaki, Hiroyuki Tsutsui
    European journal of nuclear medicine and molecular imaging 40 (3) 349 - 55 1619-7070 2013/02 [Refereed][Not invited]
     
    PURPOSE: Diastolic function is impaired in patients with end-stage heart failure. Favorable structural changes by surgical ventricular reconstruction (SVR) are thought to improve diastolic function, however, previous studies reported the contradictory results. We hypothesized that cardiac oxidative metabolism and diastolic dysfunction might improve in parallel to the reduction of left ventricular chamber size after SVR. METHODS: We studied 11 patients underwent SVR associated with mitral valve repair for end-stage heart failure due to dilated cardiomyopathy. Diastolic function was assessed by echocardiography and myocardial oxidative metabolism was measured by the monoexponential clearance (k-mono) of (11)C-acetate positron emission tomography at baseline and 1 month after SVR. RESULTS: All patients had preoperative severe diastolic dysfunction [E/A 4.11 ± 1.18, deceleration time (DT) 134 ± 26 ms]. The study patients were divided into 2 groups according to the changes in diastolic function after SVR; unchanged or worsened diastolic function in 6 patients (55 %, Non-responder) and improved diastolic function in 5 (45 %, Responder). K-mono and wall stress decreased only in responder. The changes in k-mono before and after SVR correlated with those in deceleration time (r =  -0.63; p < 0.05) and wall stress (r = 0.75; p < 0.01). CONCLUSIONS: Improvement of diastolic dysfunction in patients with end-stage heart failure by SVR was in parallel to that in oxidative metabolism. It suggests that SVR reduced excessive metabolism during the diastolic phase, in part, via the improvement in diastolic function and the reduction in LV wall stress.
  • Shiro Yamada, Mamoru Sakakibara, Takashi Yokota, Kiwamu Kamiya, Naoya Asakawa, Hiroyuki Iwano, Satoshi Yamada, Koji Oba, Hiroyuki Tsutsui
    Circulation journal : official journal of the Japanese Circulation Society 77 (5) 1214 - 20 1346-9843 2013 [Refereed][Not invited]
     
    BACKGROUND: Adaptive servo-ventilation (ASV) improves cardiac function in patients with heart failure (HF). We compared the hemodynamics of control and HF patients, and identified the predictors for acute effects of ASV in HF. METHODS AND RESULTS: We performed baseline echocardiographic measurements and hemodynamic measurements at baseline and after 15 min of ASV during cardiac catheterization in 11 control and 34 HF patients. Heart rate and blood pressure did not change after ASV in either the control or HF group. Stroke volume index (SVI) decreased from 49.3±7.6 to 41.3±7.6 ml/m2 in controls (P<0.0001) but did not change in the HF patients (from 34.8±11.5 to 32.8±8.9 ml/m2, P=0.148). In the univariate analysis, pulmonary capillary wedge pressure (PCWP), mitral regurgitation (MR)/left atrial (LA) area, E/A, E/e', and the sphericity index defined by the ratio between the short-axis and long-axis dimensions of the left ventricle significantly correlated with % change of SVI from baseline during ASV. PCWP and MR/LA area were independent predictors by multivariate analysis. Moreover, responders (15 of 34 HF patients; 44%) categorized by an increase in SVI showed significantly higher PCWP, MR, and sphericity index. CONCLUSIONS: Left ventricular structure and MR, as well as PCWP, could predict acute favorable effects on hemodynamics by ASV therapy in HF patients.
  • Hiroyuki Iwano, Satoshi Yamada, Masaya Watanabe, Hirofumi Mitsuyama, Kazuya Mizukami, Hisao Nishino, Shinobu Yokoyama, Sanae Kaga, Kazunori Okada, Mutsumi Nishida, Hisashi Yokoshiki, Taisei Mikami, Hiroyuki Tsutsui
    Circulation Journal 77 (11) 2757 - 2765 1346-9843 2013 [Refereed][Not invited]
     
    Background: We previously reported that the strain rate dispersion index (SRDI), an index of left ventricular (LV) contractility loss because of mechanical dyssynchrony, better predicted the acute response to cardiac resynchronization therapy (CRT) than time-delay indices. However, it remains unclear whether the SRDI can predict the chronic response. Additionally, the SRDI needs to be simplified for use in clinical practice. Methods and Results: Echocardiography was performed in 40 heart failure patients who underwent CRT. The SRDI, the average of segmental peak systolic strain rates minus global peak systolic strain rate, was calculated, together with strain-derived time-delay indices (St-SD) in the longitudinal, circumferential and radial directions using a speckle-tracking method. As simplified indices, the longitudinal parameters were calculated from the apical 4-chamber view in addition to 3 apical views. LV end-systolic volume (ESV) significantly decreased 6 months after CRT. Although circumferential St-SD and all SRDIs correlated with the changes in ESV (ΔESV), multivariate analysis revealed that the circumferential SRDI was the single independent determinant of ΔESV. During the 20±14 months after CRT, cardiac events occurred in 14 patients. Kaplan-Meier analyses revealed that all SRDIs were significant predictors of cardiac events whereas none of St-SDs was. Conclusions: The SRDI predicted the reduction in both LV volume and cardiac events after CRT better than timedelay indices. Additionally, a simplified SRDI could be as good a predictor of CRT response as the original.
  • Masahiro Nakabachi, Taisei Mikami, Kazunori Okada, Hisao Onozuka, Sanae Kaga, Mamiko Inoue, Shinobu Yokoyama, Mutsumi Nishida, Chikara Shimizu, Kazuhiko Matsuno, Hiroyuki Iwano, Satoshi Yamada, Hiroyuki Tsutsui
    Journal of Echocardiography 10 (3) 83 - 89 1349-0222 2012/09 [Refereed][Not invited]
     
    Background: Left ventricular (LV) diastolic dysfunction is often observed in healthy subjects and can be a cause of heart failure with preserved ejection fraction (EF). We aimed to investigate the role of LV diastolic asynchrony as a cause of diastolic dysfunction in healthy subjects. Methods: In 40 healthy subjects, two-dimensional speckle tracking imaging (2DSTI) was performed to measure the peak early diastolic longitudinal strain rates (Esr) of the apical, mid-ventricular, and basal segments of the septum and posterior wall. A mean value of the Esr of the 6 segments (mEsr) was calculated. The time from aortic valve closure to the Esr was measured for each segment, and the standard deviation (SDTEsr) was calculated. The peak global early diastolic strain rate (gEsr) was measured with a region of interest (ROI) on the whole LV myocardium. LV flow propagation velocity (FPV) was measured using conventional Doppler techniques. Results: SDTEsr was not correlated with age, but was significantly correlated with body mass index (BMI) (r = 0.41, p < 0.01). Although no significant correlation was observed between mEsr and FPV, gEsr and SDTEsr significantly correlated with FPV (r = 0.41, p < 0.01 r = -0.54, p < 0.001). As a result of the multiple regression analysis, SDTEsr was the single determinant of FPV. Conclusions: Diastolic asynchrony, associated with overweight but not with aging, may contribute to diastolic dysfunction in healthy subjects. © 2012 Japanese Society of Echocardiography.
  • Kazunori Okada, Taisei Mikami, Sanae Kaga, Hisao Onozuka, Mamiko Inoue, Shinobu Yokoyama, Hisao Nishino, Mutsumi Nishida, Kazuhiko Matsuno, Hiroyuki Iwano, Satoshi Yamada, Hiroyuki Tsutsui
    EUROPEAN JOURNAL OF ECHOCARDIOGRAPHY 12 (12) 917 - 923 1525-2167 2011/12 [Refereed][Not invited]
     
    Aims Early diastolic mitral annular velocity (e') obtained by tissue Doppler imaging (TDI) is widely used to evaluate left ventricular (LV) diastolic function based on the assumption that it reflects myocardial relaxation in the long-axis direction. In this study, we aimed to determine whether or not e' truly reflects early diastolic longitudinal myocardial relaxation, and which is the most useful for evaluating LV diastolic function among e' measured at the interventricular-septal annulus (IS-e'), that measured at the lateral annulus (LW-e') or their mean value (M-e'). Methods and results IS-e', LW-e', and M-e' were measured using colour TDI in 15 patients with hypertrophic cardiomyopathy, 13 patients with hypertension, and 19 control subjects. Using two-dimensional speckle-tracking imaging, early diastolic myocardial strain rates (SR(E)) were measured for the IS (IS-SR(E)), LW(LW-SR(E)), and entire LV myocardium (G-SR(E)). IS-e' was excellently correlated with IS-SR(E) (r = 0.90, P < 0.001); the correlation was better than that between LW-e' and LW-SR(E) (r = 0.75, P < 0.001). IS-e' and M-e' were well correlated with G-SR(E) (r = 0.88, P < 0.001 and r = 0.86, P < 0.001, respectively) and with LV early diastolic flow propagation velocity (FPV) (r = 0.77, P < 0.001 and r = 0.78, P < 0.001, respectively). The correlations of LW-e' to G-SRE (r = 0.80, P < 0.001) and FPV (r = 0.75, P < 0.001) did not reach this level. Conclusion IS-e' well reflected LV longitudinal myocardial relaxation and LV diastolic function, and was found to be more useful in evaluating LV diastolic function than LW-e'.
  • Hiroyuki Iwano, Satoshi Yamada, Masaya Watanabe, Hirofumi Mitsuyama, Hisao Nishino, Shinobu Yokoyama, Sanae Kaga, Mutsumi Nishida, Hisashi Yokoshiki, Hisao Onozuka, Taisei Mikami, Hiroyuki Tsutsui
    CIRCULATION JOURNAL 75 (9) 2167 - 2175 1346-9843 2011/09 [Refereed][Not invited]
     
    Background: Time-delay indexes are limited in predicting the response to cardiac resynchronization therapy (CRT), partly because they do not reflect the residual left ventricular (LV) contractility. We computed a novel index of LV contractility loss due to dyssynchrony (the strain rate (SR) dispersion index: SRDI) by using the speckle-tracking SR and compared the efficacy of the SRDI, time-delay indexes, and strain delay index (SDI), the previously reported index of wasted energy due to dyssynchrony, for predicting the acute response to CRT. Methods and Results: Echocardiography was performed in 19 heart failure patients (LV ejection fraction (EF) 25 +/- 6%) before and 2 weeks after CRT. The standard deviation of time to peak velocity, or strain, was calculated as time-delay indexes. The SRDI was calculated as the average of segmental peak systolic SR minus global peak systolic SR. Longitudinal SDI (L-SDI), longitudinal SRDI (L-SRDI), and circumferential SRDI (C-SRDI) significantly correlated with the change in global longitudinal strain (Delta global LSt), whereas the time-delay indexes did not. Although the time-delay indexes were comparable between responders (Delta global LSt >= 0.3%) and nonresponders, the L-SDI, L-SRDI, and C-SRDI were greater in responders. The area under the receiver operating characteristic curve of the L-SRDI, L-SDI, and C-SRDI for predicting responders was 0.89, 0.81, and 0.78, respectively. Conclusions: The SRDI correlated fairly well with an improvement in global LV systolic function after CRT. (Circ J 2011; 75: 2167-2175)
  • Takashi Sugiki, Masanao Naya, Osamu Manabe, Satoru Wakasa, Suguru Kubota, Satoru Chiba, Hiroyuki Iwano, Satoshi Yamada, Keiichiro Yoshinaga, Nagara Tamaki, Hiroyuki Tsutsui, Yoshiro Matsui
    JACC. Cardiovascular imaging 4 (7) 762 - 70 1936-878X 2011/07 [Refereed][Not invited]
     
    OBJECTIVES: The aim of this study was to investigate the effects of surgical ventricular reconstruction (SVR) on cardiac efficiency as a surrogate marker for cardiac function and oxidative metabolism in patients with severe heart failure. BACKGROUND: Our new integrated overlapping left ventriculoplasty, modified SVR, combined with mitral complex reconstruction, reduce left ventricular (LV) volume associated with improvement of symptoms of heart failure. METHODS: Twelve consecutive patients with end-stage heart failure due to nonischemic dilated cardiomyopathy (DCM) (n = 6) and ischemic dilated cardiomyopathy (ICM) (n = 6) who underwent SVR were studied. Myocardial oxidative metabolism per gram of tissue was estimated by monoexponential clearance of (11)C-acetate positron emission tomography (K(mono)). Forward stroke volume at the LV outflow tract was measured by echocardiography. Cardiac efficiency was estimated by the ratio of external work (stroke volume at the LV outflow tract index × systolic blood pressure × heart rate) to K(mono) before and 1 month after SVR. RESULTS: After SVR, medians of New York Heart Association functional class significantly improved from 3 to 1.5 (p < 0.01) in both DCM and ICM patients. End-systolic and end-diastolic volume and LV mass significantly decreased in both groups. Stroke volume at the LV outflow tract increased from 43 ± 8 ml to 52 ± 11 ml (p = 0.028) in DCM patients, but not in ICM patients (49 ± 21 ml to 59 ± 26 ml, p = 0.12). K(mono) × LV mass, as an index of global LV oxidative metabolism, decreased in DCM patients (13.6 ± 1.9 g/min vs. 8.6 ± 1.5 g/min, p = 0.03) and ICM patients (12.0 ± 3.4 g/min vs. 9.2 ± 1.0 g/min, p = 0.06). As a result, cardiac efficiency increased in all patients with DCM (3.34 ± 0.46 × 10E6 vs. 4.74 ± 0.88 × 10E6 mm Hg·ml·min/m(2), p = 0.03) and in 5 of 6 patients with ICM (4.54 ± 1.66 × 10E6 vs. 5.99 ± 2.11 × 10E6 mm Hg·ml·min/m(2), p = 0.12). CONCLUSIONS: Combined surgery with SVR and mitral complex reconstruction reduced LV volume in association with improvement of cardiac efficiency in patients with severe heart failure.
  • Masanao Naya, Satoru Chiba, Hiroyuki Iwano, Satoshi Yamada, Chietsugu Katoh, Osamu Manabe, Keiichiro Yoshinaga, Yoshiro Matsui, Nagara Tamaki, Hiroyuki Tsutsui
    European journal of nuclear medicine and molecular imaging 37 (12) 2242 - 8 1619-7070 2010/12 [Refereed][Not invited]
     
    PURPOSE: The relationship between myocardial oxidative metabolism and pressure overload in aortic valve stenosis (AS) is not fully elucidated. We identified the determinants of myocardial oxidative metabolism by measuring its changes after aortic valve replacement (AVR) in patients with AS. METHODS: Myocardial 11C-acetate clearance rate constant (Kmono), an index of oxidative metabolism, was measured non-invasively by using positron emission tomography in 16 patients with moderate to severe AS and 7 healthy controls. The severity of AS was assessed by echocardiography. Of 16 patients, 5 were reexamined at 1 month after AVR. RESULTS: Kmono was significantly higher in patients with AS than healthy controls by 42% (0.068±0.014 vs 0.048±0.007/min, p<0.01). Kmono was significantly correlated with age (r=0.58, p<0.01), left ventricular (LV) mass index (r=0.61, p<0.01) and estimated systolic LV pressure (r=0.81, p<0.001) measured by echocardiography. By multivariate analysis, estimated LV systolic pressure was an independent predictor of Kmono (β=0.93, p<0.01). After AVR, Kmono (from 0.075±0.012 to 0.061±0.014/min, p=0.043) and LV mass index (from 183±49 to 124±41 g/ml2, p=0.043) were significantly decreased despite no significant changes in rate-pressure product. CONCLUSION: Myocardial oxygen metabolism was increased in patients with AS, which was decreased after AVR. The increased myocardial oxidative metabolism in AS was largely attributable to the pressure overload of the LV.
  • Komatsu H, Yamada S, Iwano H, Okada M, Onozuka H, Mikami T, Yokoyama S, Inoue M, Kaga S, Nishida M, Shimizu C, Matsuno K, Tsutsui H
    Circulation journal : official journal of the Japanese Circulation Society 73 (11) 2098 - 2103 1346-9843 2009/11 [Refereed][Not invited]

Books etc

MISC

Research Grants & Projects

  • Impact of myocardial fibrosis on exercise capacity in heart failure with preserved ejection fraction
    Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)
    Date (from‐to) : 2018/04 -2021/03 
    Author : 岩野 弘幸, 横田 卓, 納谷 昌直, 安斉 俊久
     
    左室駆出率の保たれた慢性心不全患者(HFpEF)で呼気ガス分析を用いた心肺運動負荷試験と運動負荷心エコー検査を行い、今回新規購入した非侵襲的心拍出量モニターであるエスクロンミニRを用いて運動負荷心エコー検査時に心拍出量の計測を行った。その結果、過去に左室駆出率の低下した心不全(HFrEF)症例で認められていたのと同様に、運動耐容能の指標である最大酸素摂取量と、カラーMモード像から推定した運動時の拡張早期左室内圧較差(IVPD)との間には比較的強い正相関が認められ、さらに運動によるIVPDの変化量が運動時の心拍出量を規定することが認められた。これらの結果は、運動時の左室サクションはHFrEFと同様にHFpEFにおいても、運動時の心拍出量増大を介して運動耐容能と関連することを示唆するものと考えられた。このIVPDの低下には、左室長軸方向の機能を反映する収縮期僧帽弁輪運動速度や拡張早期僧帽弁輪運動速度の低下が関与していた。このことからは、これまでに報告されているHFpEFにおける左室の内斜走筋障害が左室長軸方向の壁伸縮を障害して左室サクションの減弱を来しているものと想定された。 しかし、未だに左室心筋線維化とサクションとの関連について検討はできておらず、今後、心臓MRIと心筋線維化バイオマーカーも併せて検討することで、研究の主目的である、HFpEFにおける心筋線維化と運動耐容能との関連性について明らかにすることを念頭に、研究を進めていく予定である。
  • Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)
    Date (from‐to) : 2012/04 -2016/03 
    Author : Naya Masanao, KINUGAWA SHINTARO, IWANO HIROYUKI, MANABE NORIKO
     
    The present study focused on the assessment of diastolic dysfunction in terms of cardiac PET in patients with heart failure. Understanding the mechanism of diastolic dysfunction can help develop new effective treatment and tailor-made therapy. Forty-one patients with heart failure and preserved ejection fraction were studied. Cardiac sympathetic function was evaluated by C11-HED PET. Cardiac sympathetic function in patients with moderate to severe diastolic dysfunction was significantly decreased than that in normal to mild function.

Educational Activities

Teaching Experience

  • 医学総論
    開講年度 : 2019
    課程区分 : 博士後期課程
    開講学部 : 医学研究科


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