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Dive into the research topics where Koichiro Asawa is active.

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Featured researches published by Koichiro Asawa.


Circulation-cardiovascular Imaging | 2009

Age- and Gender-Specific Changes in the Left Ventricular Relaxation A Doppler Echocardiographic Study in Healthy Individuals

Hiroyuki Okura; Yuko Takada; Azusa Yamabe; Tomoichiro Kubo; Koichiro Asawa; Takeshi Ozaki; Hiroyuki Yamagishi; Iku Toda; Minoru Yoshiyama; Junichi Yoshikawa; Kiyoshi Yoshida

Background—Although left ventricular diastolic function has been shown to deteriorate with advancing age, its gender-specific change is unknown. The aim of this study was to investigate age- and gender-specific changes in tissue Doppler–derived left ventricular diastolic index, E′. Methods and Results—A total of 1333 healthy individual without known heart disease or hypertension (mean age, 55 years; range, 10 to 89) were enrolled and studied. Peak early mitral annular velocity (E′) and peak late mitral annular velocity (A′) were recorded and measured. As an index of the left ventricular relaxation, E′ was used. As an index of the left ventricular filling pressure, E/E′ was calculated. Although systolic indices poorly correlated with age, diastolic indices correlated well with age. Among those aged 30 to 39 and 40 to 49 years, E′ was significantly lower in males than in females. In subjects aged 50 to 59 and 60 to 69 years, E′ was similar in both genders. Among those aged 70 to 79 and 80 to 89 years, E′ was significantly lower in females than in males. Predictors of the lowest quartile of E′ among subjects aged >50 years were age (P<0.0001; &khgr;2=66.11; odds ratio, 1.08; 95% CI, 1.058 to 1.097) and female gender (P=0.002; &khgr;2=9.23; odds ratio, 1.68; 95% CI, 1.202 to 2.343). Conclusion—Age-related changes in diastolic indices were gender specific. In the elderly population, diastolic function deteriorated more significantly in the female gender than in the male gender. These results may explain the relatively higher incidence in elderly females among patients with diastolic heart failure and higher cardiovascular mortality in the female gender.Background— Although left ventricular diastolic function has been shown to deteriorate with advancing age, its gender-specific change is unknown. The aim of this study was to investigate age- and gender-specific changes in tissue Doppler–derived left ventricular diastolic index, E′. Methods and Results— A total of 1333 healthy individual without known heart disease or hypertension (mean age, 55 years; range, 10 to 89) were enrolled and studied. Peak early mitral annular velocity (E′) and peak late mitral annular velocity (A′) were recorded and measured. As an index of the left ventricular relaxation, E′ was used. As an index of the left ventricular filling pressure, E/E′ was calculated. Although systolic indices poorly correlated with age, diastolic indices correlated well with age. Among those aged 30 to 39 and 40 to 49 years, E′ was significantly lower in males than in females. In subjects aged 50 to 59 and 60 to 69 years, E′ was similar in both genders. Among those aged 70 to 79 and 80 to 89 years, E′ was significantly lower in females than in males. Predictors of the lowest quartile of E′ among subjects aged >50 years were age ( P <0.0001; χ2=66.11; odds ratio, 1.08; 95% CI, 1.058 to 1.097) and female gender ( P =0.002; χ2=9.23; odds ratio, 1.68; 95% CI, 1.202 to 2.343). Conclusion— Age-related changes in diastolic indices were gender specific. In the elderly population, diastolic function deteriorated more significantly in the female gender than in the male gender. These results may explain the relatively higher incidence in elderly females among patients with diastolic heart failure and higher cardiovascular mortality in the female gender. Received July 22, 2008; accepted October 30, 2008. # CLINICAL PERSPECTIVE {#article-title-2}


Circulation-cardiovascular Interventions | 2010

Incidence and Predictors of Plaque Rupture in the Peripheral Arteries

Hiroyuki Okura; Koichiro Asawa; Tomoichiro Kubo; Haruyuki Taguchi; Iku Toda; Minoru Yoshiyama; Junichi Yoshikawa; Kiyoshi Yoshida

Background—Plaque rupture may be present in the peripheral arteries of the patients at high risk for cardiovascular events and is possibly associated with vascular vulnerability. Methods and Results—One hundred one iliofemoral arteries from 101 patients undergoing angioplasty were studied. Intravascular ultrasound imaging was performed before intervention. Plaque rupture was defined as presence of a cavity that communicated with the lumen with an overlying residual fibrous cap fragment. Incidence, numbers, and location of the plaque rupture were investigated. Plaque rupture was found in 42 of 101 arteries (42%). Patients with plaque rupture had significantly higher prevalence of acute coronary syndrome than did patients without plaque rupture (42% vs 16%, P=0.01). By multivariable logistic regression analysis, acute coronary syndrome (P=0.004) and male sex (P=0.01) were independent clinical correlates of plaque rupture. During follow-up (median, 14.7 months), the incidence of major adverse cardiac or cerebrovascular events (death, myocardial infarction, and ischemic stroke) was similar between the 2 groups. The incidence of major adverse cardiac or cerebrovascular events plus peripheral vascular events (unplanned vascular intervention and amputation) was significantly higher in patients with plaque rupture than in patients without plaque rupture (46% vs 21%, P=0.008). By multivariable Cox regression analysis, plaque rupture (hazard ratio=2.80, 95% CI: 1.23 to 6.37, P=0.01) and Fontaine stage IV (hazard ratio=3.50, 95% CI: 1.58 to 7.71, P=0.002) were independent predictors of major adverse cardiac or cerebrovascular events plus peripheral vascular events. Conclusions—Ruptured plaque of the iliofemoral arteries is a common finding. Patients with plaque rupture had a higher prevalence of history of acute coronary syndrome and lower major adverse cardiac or cerebrovascular events plus peripheral vascular event-free survival.


American Heart Journal | 2016

Addition of cilostazol to aspirin therapy for secondary prevention of cardiovascular and cerebrovascular disease in patients undergoing percutaneous coronary intervention: A randomized, open-label trial.

Hiroshi Ueda; Atsumichi Kido; Seiji Matsuhisa; Koichiro Asawa; Naohiro Yoshida; Mitsuru Tsujimoto; Yasushi Sasaki; Yukiko Kuga; Masaki Yamasaki; Kazuya Ueda; Shoichi Shinohara; Yasunori Nishida

BACKGROUND Patients with established coronary artery disease are at increased risk for future ischemic events and require secondary prevention for systemic vascular disease. We performed a randomized clinical trial to evaluate the impact of cilostazol on cardiovascular and cerebrovascular disease in patients undergoing percutaneous coronary intervention. METHODS A total of 514 patients who had undergone coronary stent implantation >6 months previously and were thought to no longer need dual antiplatelet therapy with aspirin and a thienopyridine were randomly assigned to receive aspirin plus cilostazol therapy or aspirin therapy alone after discontinuation of thienopyridine therapy. The primary efficacy end point was a composite of all-cause death, myocardial infarction, stroke, or cardiovascular or cerebrovascular revascularization at 2 years after randomization. The main safety end point was major or minor bleeding, according to the Thrombolysis in Myocardial Infarction bleeding definition. RESULTS At 2 years, follow-up clinical data were available for 98.1% of patients. The primary efficacy end point occurred in 13.9% of the aspirin plus cilostazol group versus 22.1% of the aspirin-only group (hazard ratio 0.61, 95% CI 0.40-0.93, P = .021). The rate of major or minor bleeding was not significantly different between the aspirin plus cilostazol and aspirin-only groups (1.6% and 4.0%, respectively, hazard ratio 0.40, 95% CI 0.13-1.28, P = .12). CONCLUSIONS In patients who underwent coronary stent implantation, the addition of cilostazol to aspirin therapy was associated with lower rates of cardiovascular and cerebrovascular events at 2 years compared with aspirin monotherapy.


The American Journal of the Medical Sciences | 2004

Quadricuspid Aortic Valve: Report of Three Cases

Masakazu Teragaki; Yosuke Sakai; Koichiro Asawa; Ryo Matsumoto; Noriaki Kasayuki; Koji Nakayama; Shinichi Tanizawa; Nobuyuki Tanaka; Shigefumi Suehiro; Junichi Yoshikawa

Quadricuspid aortic valve (QAV) is a very rare congenital malformation. We have encountered three patients with QAV, of whom one patient may be the eldest reported patient with this particular anatomical abnormality. In another of our patients, there was aortic regurgitation, aortic stenosis, and healed infective endocarditis, with adhesion of the tips of the cusps. In all three patients, the cusps were all of equal size. Until now, there has been very little documented evidence about the anatomical variations in QAV or its relationship with infective endocarditis. From the available literature, we conclude that the anatomical variations in patients with QAV are similar to those in patients with quadricuspid pulmonary valve, and infective endocarditis may not be an uncommon complication.


Circulation-cardiovascular Imaging | 2009

Age- and Gender-Specific Changes in the Left Ventricular RelaxationCLINICAL PERSPECTIVE

Hiroyuki Okura; Yuko Takada; Azusa Yamabe; Tomoichiro Kubo; Koichiro Asawa; Takeshi Ozaki; Hiroyuki Yamagishi; Iku Toda; Minoru Yoshiyama; Junichi Yoshikawa; Kiyoshi Yoshida

Background—Although left ventricular diastolic function has been shown to deteriorate with advancing age, its gender-specific change is unknown. The aim of this study was to investigate age- and gender-specific changes in tissue Doppler–derived left ventricular diastolic index, E′. Methods and Results—A total of 1333 healthy individual without known heart disease or hypertension (mean age, 55 years; range, 10 to 89) were enrolled and studied. Peak early mitral annular velocity (E′) and peak late mitral annular velocity (A′) were recorded and measured. As an index of the left ventricular relaxation, E′ was used. As an index of the left ventricular filling pressure, E/E′ was calculated. Although systolic indices poorly correlated with age, diastolic indices correlated well with age. Among those aged 30 to 39 and 40 to 49 years, E′ was significantly lower in males than in females. In subjects aged 50 to 59 and 60 to 69 years, E′ was similar in both genders. Among those aged 70 to 79 and 80 to 89 years, E′ was significantly lower in females than in males. Predictors of the lowest quartile of E′ among subjects aged >50 years were age (P<0.0001; &khgr;2=66.11; odds ratio, 1.08; 95% CI, 1.058 to 1.097) and female gender (P=0.002; &khgr;2=9.23; odds ratio, 1.68; 95% CI, 1.202 to 2.343). Conclusion—Age-related changes in diastolic indices were gender specific. In the elderly population, diastolic function deteriorated more significantly in the female gender than in the male gender. These results may explain the relatively higher incidence in elderly females among patients with diastolic heart failure and higher cardiovascular mortality in the female gender.Background— Although left ventricular diastolic function has been shown to deteriorate with advancing age, its gender-specific change is unknown. The aim of this study was to investigate age- and gender-specific changes in tissue Doppler–derived left ventricular diastolic index, E′. Methods and Results— A total of 1333 healthy individual without known heart disease or hypertension (mean age, 55 years; range, 10 to 89) were enrolled and studied. Peak early mitral annular velocity (E′) and peak late mitral annular velocity (A′) were recorded and measured. As an index of the left ventricular relaxation, E′ was used. As an index of the left ventricular filling pressure, E/E′ was calculated. Although systolic indices poorly correlated with age, diastolic indices correlated well with age. Among those aged 30 to 39 and 40 to 49 years, E′ was significantly lower in males than in females. In subjects aged 50 to 59 and 60 to 69 years, E′ was similar in both genders. Among those aged 70 to 79 and 80 to 89 years, E′ was significantly lower in females than in males. Predictors of the lowest quartile of E′ among subjects aged >50 years were age ( P <0.0001; χ2=66.11; odds ratio, 1.08; 95% CI, 1.058 to 1.097) and female gender ( P =0.002; χ2=9.23; odds ratio, 1.68; 95% CI, 1.202 to 2.343). Conclusion— Age-related changes in diastolic indices were gender specific. In the elderly population, diastolic function deteriorated more significantly in the female gender than in the male gender. These results may explain the relatively higher incidence in elderly females among patients with diastolic heart failure and higher cardiovascular mortality in the female gender. Received July 22, 2008; accepted October 30, 2008. # CLINICAL PERSPECTIVE {#article-title-2}


Circulation-cardiovascular Imaging | 2009

Age- and Gender-Specific Changes in the Left Ventricular RelaxationCLINICAL PERSPECTIVE: A Doppler Echocardiographic Study in Healthy Individuals

Hiroyuki Okura; Yuko Takada; Azusa Yamabe; Tomoichiro Kubo; Koichiro Asawa; Takeshi Ozaki; Hiroyuki Yamagishi; Iku Toda; Minoru Yoshiyama; Junichi Yoshikawa; Kiyoshi Yoshida

Background—Although left ventricular diastolic function has been shown to deteriorate with advancing age, its gender-specific change is unknown. The aim of this study was to investigate age- and gender-specific changes in tissue Doppler–derived left ventricular diastolic index, E′. Methods and Results—A total of 1333 healthy individual without known heart disease or hypertension (mean age, 55 years; range, 10 to 89) were enrolled and studied. Peak early mitral annular velocity (E′) and peak late mitral annular velocity (A′) were recorded and measured. As an index of the left ventricular relaxation, E′ was used. As an index of the left ventricular filling pressure, E/E′ was calculated. Although systolic indices poorly correlated with age, diastolic indices correlated well with age. Among those aged 30 to 39 and 40 to 49 years, E′ was significantly lower in males than in females. In subjects aged 50 to 59 and 60 to 69 years, E′ was similar in both genders. Among those aged 70 to 79 and 80 to 89 years, E′ was significantly lower in females than in males. Predictors of the lowest quartile of E′ among subjects aged >50 years were age (P<0.0001; &khgr;2=66.11; odds ratio, 1.08; 95% CI, 1.058 to 1.097) and female gender (P=0.002; &khgr;2=9.23; odds ratio, 1.68; 95% CI, 1.202 to 2.343). Conclusion—Age-related changes in diastolic indices were gender specific. In the elderly population, diastolic function deteriorated more significantly in the female gender than in the male gender. These results may explain the relatively higher incidence in elderly females among patients with diastolic heart failure and higher cardiovascular mortality in the female gender.Background— Although left ventricular diastolic function has been shown to deteriorate with advancing age, its gender-specific change is unknown. The aim of this study was to investigate age- and gender-specific changes in tissue Doppler–derived left ventricular diastolic index, E′. Methods and Results— A total of 1333 healthy individual without known heart disease or hypertension (mean age, 55 years; range, 10 to 89) were enrolled and studied. Peak early mitral annular velocity (E′) and peak late mitral annular velocity (A′) were recorded and measured. As an index of the left ventricular relaxation, E′ was used. As an index of the left ventricular filling pressure, E/E′ was calculated. Although systolic indices poorly correlated with age, diastolic indices correlated well with age. Among those aged 30 to 39 and 40 to 49 years, E′ was significantly lower in males than in females. In subjects aged 50 to 59 and 60 to 69 years, E′ was similar in both genders. Among those aged 70 to 79 and 80 to 89 years, E′ was significantly lower in females than in males. Predictors of the lowest quartile of E′ among subjects aged >50 years were age ( P <0.0001; χ2=66.11; odds ratio, 1.08; 95% CI, 1.058 to 1.097) and female gender ( P =0.002; χ2=9.23; odds ratio, 1.68; 95% CI, 1.202 to 2.343). Conclusion— Age-related changes in diastolic indices were gender specific. In the elderly population, diastolic function deteriorated more significantly in the female gender than in the male gender. These results may explain the relatively higher incidence in elderly females among patients with diastolic heart failure and higher cardiovascular mortality in the female gender. Received July 22, 2008; accepted October 30, 2008. # CLINICAL PERSPECTIVE {#article-title-2}


Circulation | 2009

Elevated E/E' Predicts Prognosis in Congestive Heart Failure Patients With Preserved Systolic Function

Hiroyuki Okura; Tomoichiro Kubo; Koichiro Asawa; Iku Toda; Minoru Yoshiyama; Junichi Yoshikawa; Kiyoshi Yoshida


Journal of The American Society of Echocardiography | 2008

Functional Mitral Regurgitation Predicts Prognosis Independent of Left Ventricular Systolic and Diastolic Indices in Patients with Ischemic Heart Disease

Hiroyuki Okura; Yuko Takada; Tomoichiro Kubo; Koichiro Asawa; Haruyuki Taguchi; Iku Toda; Minoru Yoshiyama; Junichi Yoshikawa; Kiyoshi Yoshida


American Heart Journal | 2006

Acute myocardial infarction: Clinical characteristics and plaque morphology between expansive remodeling and constrictive remodeling by intravascular ultrasound

Takao Hasegawa; Shoichi Ehara; Yoshiki Kobayashi; Toru Kataoka; Hajime Yamashita; Hiroki Nishioka; Koichiro Asawa; Hiroyuki Yamagishi; Minoru Yoshiyama; Kazuhide Takeuchi; Junichi Yoshikawa; Makiko Ueda


Internal Medicine | 2007

Impact of Statin Therapy on Systemic Inflammation, Left Ventricular Systolic and Diastolic Function and Prognosis in Low Risk Ischemic Heart Disease Patients without History of Congestive Heart Failure

Hiroyuki Okura; Koichiro Asawa; Tomoichiro Kubo; Haruyuki Taguchi; Iku Toda; Minoru Yoshiyama; Junichi Yoshikawa; Kiyoshi Yoshida

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Iku Toda

Osaka City University

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Tomoichiro Kubo

Wakayama Medical University

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Haruyuki Taguchi

Memorial Hospital of South Bend

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