Masafumi Watanabe

The University of Tokyo, 白山, Tōkyō, Japan

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Publications (55)

  • Eisuke Amiya · Masafumi Watanabe · Shogo Watanabe · [...] · Issei Komuro
    [Show abstract] [Hide abstract] ABSTRACT: Purpose The aim of this study is to investigate the relationship between arterial pulse amplitude change under increased shear stress and the presence of ischemic heart disease (IHD). Methods This study comprised 31 subjects, including 14 subjects with IHD. We investigated the change in brachial artery pulse amplitude during flow-mediated dilation (FMD) using ultrasonography. Results The arterial pulse amplitude increased during FMD in 19 subjects, whereas it decreased in 12 subjects. There was a marked difference in the change in arterial pulse amplitude (the maximum amplitude of the arterial pulse amplitude during FMD/the arterial pulse amplitude at baseline) between subjects with and without IHD (0.98 ± 0.53 and 1.37 ± 0.53, p = 0.028). Furthermore, decreased arterial pulse amplitude during FMD was a significant predictor of IHD after adjustment of age, blood pressure, the presence of each type of coronary risks, the value of FMD and sex (p = 0.0001). Conclusions The decrease of arterial pulsation amplitude during FMD was a useful predictive parameter for IHD.
    Article · Dec 2016 · SpringerPlus
  • Munenori Takata · Eisuke Amiya · Masafumi Watanabe · [...] · Issei Komuro
    Article · Aug 2016 · International journal of cardiology
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    [Show abstract] [Hide abstract] ABSTRACT: Background: Obesity has been found to be associated with future development of diastolic heart failure. Other evidence has indicated that the effect of obesity on left ventricular (LV) mass varies among ethnicities. However, there are few data on the relationship between body mass index (BMI) and LV diastolic dysfunction in the Japanese population.Methods and Results:We performed echocardiography in 788 subjects without valvular disease or LV systolic dysfunction. They were divided into 3 groups by BMI: normal weight, overweight, and obese. We used multivariable linear regression analysis to assess the clinical variables associated with diastolic parameters, including BMI. We also assessed the risk of diastolic dysfunction associated with BMI using multivariable logistic models. Overweight and obese subjects had significantly worse LV diastolic function and greater LV mass than normal weight subjects. In the multivariable analysis, BMI was independently associated with diastolic parameters. Furthermore, after adjusting for clinical factors, the increased risks of diastolic dysfunction in overweight subjects (adjusted odds ratio: 2.02, 95% confidence interval 1.21-3.36) and obese subjects (4.85, 3.36-16.27) were greater than those previously observed in Western populations. Conclusions: The Japanese population might be more susceptible than Western subjects to the effect of BMI on LV diastolic function. Differences between ethnicities should be taken into consideration in strategies for the prevention of diastolic heart failure.
    Full-text Article · Jul 2016 · Circulation Journal
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    [Show abstract] [Hide abstract] ABSTRACT: Background: Increased left atrial volume (LAV) predicts a higher incidence of cardiovascular events and is widely recognized as a major surrogate marker of left ventricular (LV) diastolic dysfunction (DD). Although the pathophysiology of LA enlargement is probably multifactorial, few studies have examined comprehensively the clinical factors that lead to LA enlargement in the absence of valvular disease or LV systolic dysfunction. Therefore, we investigated associations between LAV and several clinical and echocardiographic parameters including DD. Methods: We enrolled 557 subjects without significant valve disease or LV systolic dysfunction from the health check-up clinic retrospectively. We performed univariable and multivariable linear regression using lnLAV index as the dependent variable and the following independent variables: gender, age, smoking status, drinking habit, hypertension, diabetes, body mass index (BMI), LV ejection fraction, DD, LV mass index, hemoglobin, serum creatinine, serum total cholesterol, serum uric acid, serum sodium, and serum iron. Results: In multivariable analysis, LAV index was independently associated with BMI, lower hemoglobin, and moderate and severe DD compared with normal diastolic function (p<0.001), but not with mild DD (p=0.70). Conclusions: LA enlargement was independently associated with moderate and severe DD, but not with mild DD. Furthermore, obesity and lower hemoglobin were associated with LAV independently of DD.
    Full-text Article · Mar 2016 · Journal of Cardiology
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    [Show abstract] [Hide abstract] ABSTRACT: We present the first case of multiple coronary artery-left ventricular micro fistulae complicated with hepatic arteriovenous fistulae (AVF) in an adult patient. Multiple coronary artery fistulae originated from the left anterior descending coronary artery with aneurysmal change. Multiple coronary artery-left ventricular micro fistulae presented on the left ventricular wall and showed significant localized hypertrophic change. Stress and enhanced cardiac magnetic resonance imaging (CMR) revealed myocardial ischemia that could not be detected by stress Tl-201 cardiac scintigraphy, and late patchy gadolinium enhancement (LGE) in the mid-ventricular wall apex. This LGE pattern did not match the typical pattern observed in patients with apical hypertrophic cardiomyopathy. These observations may help distinguish multiple coronary artery-associated myocardial ischemia and hypertrophy from apical cardiomyopathy.
    Full-text Article · Jan 2016 · International Heart Journal
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    [Show abstract] [Hide abstract] ABSTRACT: Background: The prevalence of left ventricular diastolic dysfunction (LVDD) sharply increases in women after their 50s and may contribute to the high prevalence of diastolic heart failure in elderly women. A decrease in estrogen levels after menopause is postulated to be one of the mechanisms responsible for this phenomenon. However, there is a paucity of data on the relationship between the timing of menopause and the progression of LVDD in the clinical setting; thus, we investigated this relationship in healthy postmenopausal women. Methods: We enrolled 115 women and divided them into two groups according to median menopause age: 61 who experienced menopause at ≤50 years (early menopause group), and 54 who experienced menopause at >50 years (late menopause group). We compared the echocardiographic and clinical characteristics between the two groups. Results: There were no significant differences in LV diastolic parameters (mitral E/A, p=0.561; e', p=0.052; E/e', p=0.081; DCT, p=0.082; prevalence of LVDD class, p=0.801), as well as other echocardiographic parameters and clinical characteristics between the two groups. Multivariate linear regression analysis showed that the independent determinants of LVDD were age and body mass index, but not the timing of menopause. Conclusions: Early menopause did not influence the progression of LVDD in postmenopausal women. The sharp progression of LVDD in elderly women is complex and probably influenced by multiple factors.
    Full-text Article · Jan 2016 · Journal of Cardiology
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    Toshihiro Yamaguchi · Eisuke Amiya · Masafumi Watanabe · Issei Komuro
    [Show abstract] [Hide abstract] ABSTRACT: Afterload is considered to be an important factor regulating heart failure. Aortic structure or pathology may affect afterload to various extents. However, the contribution of aortic diseases, such as aortic aneurysm or aortic dissection, to heart failure status has not been completely elucidated.Here we describe a 78-year-old patient with severe heart failure who made a dramatic recovery from cardiac decompensation following endovascular thoracic aortic aneurysm surgery. He previously underwent graft replacement for impending rupture of the descending aorta and replacement of both the mitral valve and aortic valve to address valve regurgitation. Subsequently, his left ventricular (LV) function became severely depressed (13%) and serum brain natriuretic peptide (BNP) level remained high (approximately 880-3520 pg/mL). Conversely, his aortic arch was dilated to 70 mm and required surgical intervention. Despite his extremely high vascular surgery risk due to severely depressed cardiac function, stent grafting for thoracic aortic aneurysm was successfully performed. Furthermore, the severity of his depressed cardiac function and heart failure dramatically improved following stent grafting. The left ventricular ejection fraction improved from 13% presurgery to 55% postsurgery and the serum BNP level had significantly decreased to 70- 240 pg/mL. These improvements helped to alleviate the patient's heart failure symptoms, including shortness of breath.This case suggests a possible beneficial effect of aortic aneurysm repair for improving cardiac function and heart failure; our study presents a new concept of another extrinsic factor that can affect cardiac function through modulation of afterload.
    Full-text Article · Nov 2015 · International Heart Journal
  • Eisuke Amiya · Masanobu Taya · Masafumi Watanabe
    Article · Nov 2015 · International Heart Journal
  • Eisuke Amiya · Masanobu Taya · Masafumi Watanabe
    Article · Nov 2015 · International Heart Journal
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    Full-text Article · Oct 2015 · Circulation Journal
  • Munenori Takata · Eisuke Amiya · Masafumi Watanabe · [...] · Issei Komuro
    [Show abstract] [Hide abstract] ABSTRACT: The clinical meaning of changes in PP with posture remains unclear. We performed treadmill exercise testing on 144 subjects to diagnose ischemic heart disease, and measured the PPs in the supine and standing positions. The differences in the two PPs ranged between -35 and 45 mmHg. Eleven subjects were diagnosed with significant coronary ischemia. The differences in the PPs were significantly increased, and PP in the standing position was significantly elevated in these subjects. A large difference in the PPs in the standing and supine positions was associated with significant coronary ischemia, independent of significant covariables.
    Article · Aug 2015 · Clinical and Experimental Hypertension
  • Article · Jul 2015 · International journal of cardiology
  • [Show abstract] [Hide abstract] ABSTRACT: Congenital contractural arachnodactyly (CCA) is a rare connective tissue disorder characterized by marfanoid habitus with camptodactyly. However, cardiac features have rarely been documented in adults. We herein report a sporadic case of CCA in a 20-year-old woman who developed decompensated dilated cardiomyopathy. The patient did not have any mutations in the FBN1 or FBN2 genes, which are most commonly associated with Marfan syndrome and CCA, respectively. Although whether these two diseases are caused by a mutation(s) in the same gene or two different genes remains unknown, this case provides new clinical insight into the cardiovascular management of CCA.
    Article · May 2015 · Internal Medicine
  • [Show abstract] [Hide abstract] ABSTRACT: Acute kidney injury (AKI) is relatively common after cardiothoracic surgery for type A acute aortic dissection (TA-AAD) and increases mortality. We investigated the incidence and risk factors for AKI in patients with TA-AAD and its impact on their outcomes. The records of 375 consecutive patients who underwent surgical treatment for TA-AAD from October 2007 to March 2013 were analyzed retrospectively. We defined AKI using the Kidney Disease Improving Global Outcomes criteria, which are based on serum creatinine concentration or glomerular filtration rate. We used Kaplan-Meier methods and multivariate Cox proportional hazards regression to assess the impact of AKI on both mortality and major adverse cardiovascular and cerebrovascular events. We also examined the association between risk factors and AKI using logistic regression modeling. Postoperative AKI was observed in 165 patients (44.0%). The overall 30-day and mid- to long-term mortality was 1.6% and 8.8%, respectively. Mortality and major adverse cardiovascular and cerebrovascular events correlated significantly with the severity of AKI, and multivariate analysis showed that AKI stage 3 (the most sever stage) was an independent risk factor for mortality (hazard ratio 6.83, 95% confidence interval 2.52 to 18.52) after adjustment for important confounding factors. Extracorporeal circulation time, body mass index, perioperative peak serum C-reactive protein concentration, renal malperfusion, and perioperative sepsis were found to be risk factors for AKI. In conclusion, AKI was common in patients who underwent surgery for type A acute aortic dissection. The severity of AKI strongly influences patient outcomes, so it should be recognized promptly and treated aggressively when possible. Copyright © 2015 Elsevier Inc. All rights reserved.
    Article · May 2015 · The American Journal of Cardiology
  • Conference Paper · Mar 2015
  • Article · Nov 2014 · Amyloid
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    Shogo Watanabe · Eisuke Amiya · Masafumi Watanabe · [...] · Issei Komuro
    [Show abstract] [Hide abstract] ABSTRACT: Purpose The physiological role of vasomotion, rhythmic oscillations in vascular tone or diameter, and its underlying mechanisms are unknown. We investigated the characteristics of brachial artery vasomotion in patients with ischemic heart disease (IHD). Methods We performed a retrospective study of 37 patients with IHD. Endothelial function was assessed using flow-mediated dilation (FMD), and power spectral analysis of brachial artery diameter oscillations during FMD was performed. Frequency-domain components were calculated by integrating the power spectrums in three frequency bands (in ms2) using the MemCalc (GMS, Tokyo, Japan): very-low frequency (VLF), 0.003–0.04 Hz; low frequency (LF), 0.04–0.15 Hz; and high frequency (HF), 0.15–0.4 Hz. Total spectral power (TP) was calculated as the sum of all frequency bands, and each spectral component was normalized against TP. Results Data revealed that HF/TP closely correlated with FMD (r = −0.33, p = 0.04), whereas VLF/TP and LF/TP did not. We also explored the relationship between elevated C-reactive protein (CRP) levels and vasomotion. HF/TP was significantly increased in subjects with high CRP levels (CRP;>0.08 mg/dL) compared with subjects with low CRP levels (0.052±0.026 versus 0.035±0.022, p<0.05). The HF/TP value closely correlated with CRP (r = 0.24, p = 0.04), whereas the value of FMD did not (r = 0.023, p = 0.84). In addition, elevated CRP levels significantly increased the value of HF/TP after adjustment for FMD and blood pressure (β = 0.33, p<0.05). Conclusion The HF component of brachial artery diameter oscillation during FMD measurement correlated well with FMD and increased in the presence of elevated CRP levels in subjects with IHD.
    Full-text Article · Oct 2014 · PLoS ONE
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    [Show abstract] [Hide abstract] ABSTRACT: Background: In-stent restenosis (ISR) is still a recognized clinical problem in the era of drug-eluting stent (DES). Some previous studies have suggested that circulating eosinophils play an important role in both restenosis and thrombosis after DES implantation. However, the contribution of eosinophils to the pathogenesis of ISR has not yet been concisely clarified. Case report: We present the case of an 83-year-old male Japanese patient with ISR exacerbated by drug-induced severe eosinophilia. He had previous histories of coronary stent implantations by DES and was referred to our hospital because of erythema with severe eosinophilia (maximum was 6500/μl [48% of total white blood cell count]). Around the same time, the patient developed ISR, for which a stent was deployed 2 years earlier. Arterial wall injury due to the increase in circulating eosinophils was verified in several findings, such as the increase of D-dimer and brain natriuretic peptide. In addition, the histology of the resected tissue from erythema demonstrated that the nuclei of endothelial cells were swollen where eosinophils and lymphocytes heavily infiltrated into the extravascular space, suggesting the presence of vascular injury. This injury due to the increase in circulating eosinophils may have a marked impact on the pathologic process of ISR in DES implantation. Conclusions: Just a few anecdotal reports are available of ISR occurring in the setting of hypereosinophilia. The clarification of the mechanism in this patient provides a new effective therapeutic strategy against ISR in the setting of DES implantation.
    Full-text Article · Sep 2014 · American Journal of Case Reports
  • Eisuke Amiya · Masafumi Watanabe · Issei Komuro
    [Show abstract] [Hide abstract] ABSTRACT: Endothelial dysfunction and autonomic nervous system dysfunction are both risk factors for atherosclerosis. There is evidence demonstrating that there is a close interrelationship between these two systems. In hypertension, endothelial dysfunction affects the pathologic process through autonomic nervous pathways, and the pathophysiological process of autonomic neuropathy in diabetes mellitus is closely related with vascular function. However, detailed mechanisms of this interrelationship have not been clearly explained. In this review, we summarize findings concerning the interrelationship between vascular function and the autonomic nervous system from both experimental and clinical studies. The clarification of this interrelationship may provide more comprehensive risk stratification and a new effective therapeutic strategy against atherosclerosis.
    Article · Jul 2014 · Annals of Vascular Diseases
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    Atsuko Ozeki · Eisuke Amiya · Masafumi Watanabe · [...] · Ryozo Nagai
    [Show abstract] [Hide abstract] ABSTRACT: The aim of this study was to evaluate the add-on effect of aliskiren to valsartan on endothelial-dependent vasodilation in hypertensive patients with ischemic heart disease (IHD). After 4 weeks of treatment with 80 mg of valsartan, 28 patients were allocated to either continued treatment with valsartan or an add-on treatment with valsartan plus 150 mg of aliskiren. Aliskiren significantly decreased plasma renin activity, whereas endothelium-dependent vasodilation measured by flow-mediated dilation (FMD) did not change. In contrast, heart rate significantly decreased (73.1 ± 9.8 to 66.3 ± 7.0 beats per minute at baseline and 24 weeks, respectively [P = .009]) and the standard deviation of the R-R intervals (SDNN) significantly increased in the aliskiren group. The add-on aliskiren to valsartan therapy may not improve endothelial functions, although it significantly reduced resting heart rate via regulation of the autonomic nervous system in hypertensive patients with IHD.
    Full-text Article · Jul 2014 · Journal of Clinical Hypertension