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Dive into the research topics where Takayuki Ohtsuka is active.

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Featured researches published by Takayuki Ohtsuka.


Journal of Cardiology | 2010

Clinical outcome after acute coronary syndrome in Japanese patients: An observational cohort study

Michinari Nakamura; Takeshi Yamashita; Junji Yajima; Yuji Oikawa; Ken Ogasawara; Koichi Sagara; Hajime Kirigaya; Akira Koike; Kazuyuki Nagashima; Takayuki Ohtsuka; Tokuhisa Uejima; Shinya Suzuki; Hitoshi Sawada; Tadanori Aizawa

BACKGROUND Mortality and morbidity after acute coronary syndrome (ACS) in Japan appear to be different from those in Western countries due to different social healthcare systems, races, geographical locations, and interventional procedures, although data are limited in Japan. METHODS With a hospital-based cohort study comprising all the new patients who had visited our hospital between 2004 and 2007 (n=6562), we identified all-cause mortality, the composite endpoint of cardiac death, non-fatal myocardial infarction (MI), or target vessel revascularization and the predictors. RESULTS Of the total, 293 patients were included with a discharge diagnosis of ACS (median follow-up of 24.5 months). Non-ST elevation-ACS (NSTE-ACS) (unstable angina and non-ST elevation MI) and ST elevation MI (STEMI) were observed in 165 (56.3%) and 128 (43.7%) patients, respectively. Percutaneous coronary intervention or coronary artery bypass graft surgery was performed in 72.7% and 14.5% of NSTE-ACS patients, respectively and in 82.8% and 10.2% of STEMI patients. The use of aspirin, ticlopidine, and beta-blockers for NSTE-ACS patients were 93.3%, 66.9%, and 38.0%, respectively, with corresponding rates of 96.0%, 75.4%, and 57.1% for STEMI patients. All-cause mortality rates in NSTE-ACS and STEMI were 1.8% and 5.5% at 30 days, respectively, and 6.3% and 12.9% at 2 years, with corresponding rates of 3.7% and 8.7% at 30 days, respectively, and 23.4% and 35.6% at 2 years for the composite endpoint. Multivariate analysis showed that predictors for mortality were older age (hazard ratio [HR] 1.13, 95% confidence interval [CI] 1.018-1.244) and estimated glomerular filtration rate value (HR 0.96, 95% CI 0.929-0.988) in NSTE-ACS, and older age (HR 1.10, 95% CI 1.011-1.119) and congestive heart failure on admission (HR 20.0, 95% CI 2.439-164.4) in STEMI. CONCLUSIONS The present study identified long-term mortality, morbidity, and predictors of adverse events for Japanese patients with ACS.


Journal of Cardiology | 2010

Heart failure with preserved versus reduced left ventricular systolic function: A prospective cohort of Shinken Database 2004—2005

Ayumi Goda; Takeshi Yamashita; Shinya Suzuki; Takayuki Ohtsuka; Tokuhisa Uejima; Yuji Oikawa; Junji Yajima; Akira Koike; Kazuyuki Nagashima; Hajime Kirigaya; Koichi Sagara; Ken Ogasawara; Mitsuaki Isobe; Hitoshi Sawada; Tadanori Aizawa

BACKGROUND Several hospital-based investigations have reported that a high proportion of patients with heart failure (HF) have preserved left ventricular ejection fraction (LVEF). The purpose of this study was to determine the prevalence, prognosis, and predictors for mortality of Japanese HF patients with preserved versus reduced LVEF in a prospective cohort fashion. METHODS AND RESULTS Our hospital-based database including inpatients and also outpatients was used for analysis. Out of 4255 new patients, 597 patients (male/female 414/183, age 65.1+/-12.9 years) were diagnosed as having symptomatic HF at the initial visit. Among 589 HF patients undergoing echocardiography, 398 (67.6%) showed a preserved LVEF (>50%) and 191 (32.4%) had a reduced LVEF (< or =50%). Patients with preserved LVEF were older (p=0.004) and more likely to be female (p=0.002). During follow-up of an average 539 days, 34 cardiovascular deaths occurred, and patients with preserved LVEF showed a better prognosis than those with reduced LVEF (3.2% vs. 7.4% per year, p=0.0097). Multivariate Cox hazards analysis identified LVEF as an independent predictor in all HF patients. Also, separated group analysis showed that presence of chronic kidney disease was independently associated with poor prognosis irrespective of HF types. CONCLUSIONS This prospective cohort study identified prevalence and prognosis of HF in Japanese in- and outpatients, where patients with preserved LVEF showed a better prognosis than those with reduced LVEF.


Journal of Arrhythmia | 2015

Enlargement of the left atrium is associated with increased infiltration of immune cells in patients with atrial fibrillation who had undergone surgery

Takeshi Yamashita; Akiko Sekiguchi; Shinya Suzuki; Takayuki Ohtsuka; Koichi Sagara; Hiroaki Tanabe; Takashi Kunihara; Hitoshi Sawada; Tadanori Aizawa

Enlargement of the left atrium (LA) is a risk factor of atrial fibrillation (AF) recurrence after pharmacological and nonpharmacological interventions for AF. However, structural changes associated with LA enlargement have not been fully elucidated.


Journal of Arrhythmia | 2015

Relation between frequency of activated partial prothrombin time measurements and clinical outcomes in patients after initiation of dabigatran: A two-center cooperative study

Takeshi Yamashita; Shigeo Horinaka; Noritaka Matsuhashi; Naoko Suzuki; Shinya Suzuki; Takayuki Ohtsuka; Kouichi Sagara

Although activated partial prothrombin time (aPTT) has often been used as a biomarker for evaluating the safety of dabigatran use in patients with non‐valvular atrial fibrillation (NVAF), the optimal frequency of aPTT measurements is unclear. This study aimed to identify the frequency distribution of aPTT measurements in clinical practice and its clinical significance.


Circulation | 2008

Prevalence and Prognosis of Patients With Atrial Fibrillation in Japan : A Prospective Cohort of Shinken Database 2004

Shinya Suzuki; Takeshi Yamashita; Takayuki Ohtsuka; Koichi Sagara; Tokuhisa Uejima; Yuji Oikawa; Junji Yajima; Akira Koike; Kazuyuki Nagashima; Hajime Kirigaya; Ken Ogasawara; Hitoshi Sawada; Tadanori Aizawa


Circulation | 2010

Body Size and Atrial Fibrillation in Japanese Outpatients

Shinya Suzuki; Takeshi Yamashita; Takayuki Ohtsuka; Koichi Sagara; Tokuhisa Uejima; Yuji Oikawa; Junji Yajima; Akira Koike; Kazuyuki Nagashima; Hajime Kirigaya; Ken Ogasawara; Hitoshi Sawada; Tsutomu Yamazaki; Tadanori Aizawa


International Heart Journal | 2009

Prevalence and prognosis of patients with heart failure in Tokyo: a prospective cohort of Shinken Database 2004-5.

Ayumi Goda; Takeshi Yamashita; Shinya Suzuki; Takayuki Ohtsuka; Tokuhisa Uejima; Yuji Oikawa; Junji Yajima; Akira Koike; Kazuyuki Nagashima; Hajime Kirigaya; Koichi Sagara; Ken Ogasawara; Mitsuaki Isobe; Hitoshi Sawada; Tadanori Aizawa


Japanese Circulation Journal-english Edition | 2008

1 Lessons from a Prospective Cohort Study of Shinken Database 2004-5 : Mortality and Morbidity of Japanese AF Patients under Standard Management(Symposium 6 (SY-06) (A) Recent Strategies for Total Management of Atrial Fibrillation,Special Program,The 72nd Annual Scientific Meeting of the Japanese Circulation Society)

Takeshi Yamashita; Shinya Suzuki; Takayuki Ohtsuka; Koichi Sagara; Tokuhisa Uejima; Yuji Oikawa; Junji Yajima; Akira Koike; Kazuyuki Nagashima; Hajime Kirigaya; Ken Ogasawara; Hitoshi Sawada; Tadanori Aizawa


Journal of Arrhythmia | 2011

Heart Rate Turbulence in Patients with Systolic Heart Failure

Yumiko Tsutsumi; Etsuko Hayama; Shinya Suzuki; Kouichi Sagara; Takayuki Ohtsuka; Yuji Oikawa; Junji Yajima; Akira Koike; Kazuyuki Nagashima; Hajime Kirigaya; Takeshi Yamashita


Japanese Circulation Journal-english Edition | 2009

PJ-147 The Role of Atrial Fibrillation in Prognosis in Japanese Patients with Acute Coronary Syndrome(PJ025,Arrhythmia, Others (Clinical/Diagnosis/Treatment) 2 (A),Poster Session (Japanese),The 73rd Annual Scientific Meeting of The Japanese Circulation Society)

Masaaki Shoji; Takeshi Yamashita; Shinya Suzuki; Takayuki Ohtsuka; Koichi Sagara; Tokuhisa Uejima; Yuji Oikawa; Junji Yajima; Akira Koike; Kazuyuki Nagashima; Hajime Kirigaya; Ken Ogasawara; Hitoshi Sawada; Tadanori Aizawa

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Takeshi Yamashita

Cardiovascular Institute of the South

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Tadanori Aizawa

Cardiovascular Institute of the South

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Hitoshi Sawada

Marine Biological Laboratory

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Koichi Sagara

Cardiovascular Institute of the South

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Shinya Suzuki

Cardiovascular Institute of the South

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Akira Koike

Cardiovascular Institute of the South

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Tokuhisa Uejima

Cardiovascular Institute of the South

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Hajime Kirigaya

Cardiovascular Institute of the South

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Junji Yajima

Cardiovascular Institute of the South

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Kazuyuki Nagashima

Cardiovascular Institute of the South

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