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Dive into the research topics where Hiroatsu Yokoi is active.

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Featured researches published by Hiroatsu Yokoi.


The New England Journal of Medicine | 1996

Three-year follow-up after implantation of metallic coronary-artery stents

Takeshi Kimura; Hiroyoshi Yokoi; Yoshihisa Nakagawa; Takashi Tamura; Satoshi Kaburagi; Yoshihiro Sawada; Yasukazu Sato; Hiroatsu Yokoi; Naoya Hamasaki; Hideyuki Nosaka; Masakiyo Nobuyoshi

BACKGROUND Coronary-artery stents are known to reduce rates of restenosis after coronary angioplasty, but it is uncertain how long this benefit is maintained. METHODS We evaluated clinical and angiographic follow-up information for up to three years after the implantation of Palmaz-Schatz metallic coronary-artery stents in 143 patients with 147 lesions of native coronary arteries. RESULTS The rate of survival free of myocardial infarction, bypass surgery, and repeated coronary angioplasty for stented lesions was 74.6 percent at three years. After 14 months, revascularization of the stented lesion was necessary in only three patients (2.1 percent). In contrast, coronary angioplasty for a new lesion was required in 11 patients (7.7 percent). Follow-up coronary angiography of 137 lesions at six months, 114 lesions at one year, and 72 lesions at three years revealed a decrease in minimal luminal diameter from 2.54 +/- 0.44 mm immediately after stent implantation to 1.87 +/- 0.56 mm at six months, but no further decrease in diameter at one year (in patients with paired angiograms, 1.95 +/- 0.49 mm at both six months and one year). Significant late improvement in luminal diameter was observed at three years (in patients with paired angiograms, 1.94 +/- 0.48 mm at six months and 2.09 +/- 0.48 mm at three years; P < 0.001). CONCLUSIONS Clinical and angiographic outcomes up to three years after coronary-artery stenting were favorable, with a low rate of revascularization of the stented lesions. Late improvement in luminal diameter appears to occur between six months and three years.


Journal of the American College of Cardiology | 1991

Restenosis after percutaneous transluminal coronary angioplasty: pathologic observations in 20 patients.

Masakiyo Nobuyoshi; Takeshi Kimura; Hiroto Ohishi; Hisanori Horiuchi; Hideyuki Nosaka; Naoya Hamasaki; Hiroatsu Yokoi; Koutaku Kim

Histopathologic examination was performed in 20 patients undergoing antemortem coronary angioplasty. Thirty-four lesions were dilated and the interval between coronary angioplasty and death ranged from several hours to 4 years. Intimal proliferation of smooth muscle cells, as a major cause of restenosis, was observed in 83% to 100% of 28 lesions examined 11 days to 2 years after coronary angioplasty. In 20 lesions examined within 6 months, proliferating smooth muscle cells were predominantly of the synthetic type and there was abundant extracellular matrix substance chiefly composed of proteoglycans. In eight lesions examined between 6 months and 2 years, contractile type smooth muscle cells were dominant and extracellular matrix was composed chiefly of collagen. In three lesions examined after 2 years, evidence of antemortem coronary angioplasty was hardly identifiable and these lesions were almost indistinguishable from conventional atherosclerotic plaque. These temporal changes in histologic pattern provide a pathologic background for clinical reports that restenosis is predominantly found within 6 months after coronary angioplasty. Morphometric analysis revealed that the extent of intimal proliferation was significantly greater in lesions with evidence of medial or adventitial tears than in lesions with no or only intimal tears.


International Heart Journal | 2015

Clinical Characteristics and Long-Term Outcomes of Hypertrophic Cardiomyopathy

Masataka Yoshinaga; Daiji Yoshikawa; Hideki Ishii; Akihiro Hirashiki; Takahiro Okumura; Aki Kubota; Shinichi Sakai; Ken Harada; Fuji Somura; Tomofumi Mizuno; Wakaya Fujiwara; Hiroatsu Yokoi; Mutsuharu Hayashi; Junichi Ishii; Yukio Ozaki; Toyoaki Murohara; Yukihiko Yoshida; Tetsuya Amano; Hideo Izawa

Hypertrophic cardiomyopathy (HCM) has various morphological and clinical features. A decade has passed since the previous survey of the epidemiological and clinical characteristics of Japanese HCM patients. The Aichi Hypertrophic Cardiomyopathy (AHC) Registry is based on a prospective multicenter observational study of HCM patients. The clinical characteristics of 42 ambulant HCM patients followed up for up to 5 years were investigated. The primary endpoint was major adverse cardiac events (MACE), defined as death, non-fatal stroke, admission due to congestive heart failure (CHF), or episodes of sustained ventricular tachycardia/fibrillation. The MACE-free survival during the 5-year follow-up period was 76% according to Kaplan-Meier analysis. HCM-related death occurred in 3 (7%) patients and SCD occurred in 2 (5%) patients. Additionally, 3 (7%) patients were admitted to the hospital due to CHF. Meanwhile, sustained VT was detected in one (2%) of the patients who received ICD implantation and subsequently terminated with antitachycardia pacing using an ICD. The patients with HCM exhibiting left ventricular outflow obstruction (HOCM) had a slightly lower MACE-free survival rate than those with neither HOCM nor dilated-HCM (dHCM) (71% versus 81%, log-rank P = 0.581). Furthermore, the patients with dHCM demonstrated a significantly lower MACE-free survival rate than those with neither HOCM nor dHCM (33% versus 81%, log-rank P = 0.029). In the AHC Registry targeting current Japanese HCM patients, we demonstrated that many HCM patients continue to suffer from MACE despite the development of various treatments for HCM.


Internal Medicine | 2015

Takotsubo cardiomyopathy with involvement of delayed-onset rhabdomyolysis and acute kidney injury after rosuvastatin treatment.

Tomohito Kamada; Mutsuharu Hayashi; Hiroatsu Yokoi; Wakaya Fujiwara; Daiji Yoshikawa; Daisuke Mukaide; Yoshinori Sugishita; Masataka Yoshinaga; Takehiro Ito; Yukio Ozaki; Hideo Izawa

Takotsubo cardiomyopathy is a disorder characterized by left ventricular apical ballooning with preceding emotional and/or physical stressors. This condition is also an important differential diagnosis of acute coronary syndrome. We herein describe a case of Takotsubo cardiomyopathy, a significant clinical phenomenon, triggered by delayed-onset rhabdomyolysis following the administration of long-term statin treatment, without any preceding stressors or changes in the patients medical condition, in association with complaints of non-specific muscle-related symptoms. Although an electrocardiogram showed remarkable ST-segment elevation, a careful reading of the electrocardiogram findings revealed the features of Takotsubo cardiomyopathy. Withdrawing the statin therapy improved the patients cardiac function.


Heart and Vessels | 2013

Low dose of hydrochlorothiazide, in combination with angiotensin receptor blocker, reduces blood pressure effectively without adverse effect on glucose and lipid profiles

Wakaya Fujiwara; Hideo Izawa; Gen Ukai; Hiroatsu Yokoi; Daisuke Mukaide; Kohsuke Kinoshita; Shin-ichiro Morimoto; Junichi Ishii; Yukio Ozaki; Masanori Nomura

Previous studies have shown highly effective lowering of blood pressure with thiazide diuretics in combination with angiotensin receptor blockers. However, thiazide diuretics may cause the development of diabetes and abnormal lipid metabolism. Little is known as to whether dysmetabolic potential of thiazide diuretics could be neutralized when adding angiotensin receptor blockers. This study consisted of 26 patients with essential hypertension. Patients were randomized to 24 weeks of treatment with either candesartan, 12 mg monotherapy (n = 13, group A), or hydrochlorothiazide (HCTZ), 6.25 mg in combination with candesartan, 8 mg (n = 13, group B). Before and after treatment, we assessed glucose and lipid profiles including adiponectin, resistin, and active glucagon-like peptide-1 (GLP-1) levels. At baseline, there were no differences in age, body mass index, systolic blood pressure (SBP), and diastolic blood pressure (DBP), as well as plasma levels of hemoglobin A1c, insulin, low-density lipoprotein cholesterol, triglycerides, adiponectin, resistin, and active GLP-1 between the two groups. There were significant reductions in SBP (from 152 ± 10 mmHg at baseline to 134 ± 12 mmHg after treatment) and DBP (from 84 ± 5 mmHg at baseline to 71 ± 8 mmHg after treatment) in group A. There were also significant reductions in SBP (from 148 ± 10 at baseline to 128 ± 7 mmHg after treatment) and DBP (from 90 ± 9 at baseline to 74 ± 12 mmHg after treatment) in group B. There were no differences in reduction of SBP or DBP after 24 weeks of treatment between the two groups. There were no changes of the glucose and lipid profiles, including adiponectin, resistin, insulin, and active GLP-1 levels after 24 weeks of treatment in both groups. A low dose of HCTZ in combination with candesartan reduces blood pressure effectively without adverse effects on the glucose and lipid profiles. Therefore, the combination of thiazide diuretics and angiotensin receptor blockers could assist patients in achieving long-term control of blood pressure with good tolerability.


Drug and Chemical Toxicology | 2017

Antihypertensive efficacy and safety of the angiotensin receptor blocker azilsartan in elderly patients with hypertension.

Tomohito Kamada; Mutsuharu Hayashi; Wakaya Fujiwara; Daiji Yoshikawa; Daisuke Mukaide; Yoshinori Sugishita; Masataka Yoshinaga; Takehiro Itoh; Hiroatsu Yokoi; Junichi Ishii; Eiichi Watanabe; Yukio Ozaki; Hideo Izawa

Abstract Objectives: The number of elderly patients with hypertension has been steadily increasing. However, there are limited data on the safety and efficacy of the new angiotensin type 1 receptor blocker (ARB) azilsartan in elderly patients with hypertension. We investigated the clinical efficacy and safety of azilsartan in this population. Methods: The study population comprised 56 ambulatory patients with essential hypertension. We evaluated the reduction in blood pressure and safety after 12 weeks of treatment with azilsartan in 29 hypertensive patients ≥65 years of age (aged group) in comparison with the findings in 27 patients <65 years of age (non-aged group). Results: Systolic blood pressure in the aged group declined significantly from 155 ± 18 mmHg at baseline to 138 ± 11 mmHg after 12 weeks of treatment with azilsartan, and that in the non-aged group also declined significantly from 152 ± 20 mmHg at baseline to 142 ± 13 mmHg after 12 weeks of treatment with azilsartan. There were no significant differences in the magnitude of change in blood pressures from pre-treatment to post-treatment with azilsartan between the non-aged and aged groups. There were no changes in clinical laboratory findings, including serum levels of creatinine, potassium, lipids, and other metabolic variables, after 12 weeks of treatment with azilsartan in both groups. Conclusions: Our findings suggest that azilsartan is effective in lowering blood pressure in elderly patients and may be safe. Therefore, azilsartan could be a valuable option for treating hypertension in elderly and non-elderly patients.


Journal of Electrocardiology | 1999

T wave alternans in patients with cardiac sarcoidosis

Takeshi Shimaji; Y Nakamura; Masaru Kinoshita; Atsushi Kani; K Katoh; M Ishihara; Hiroatsu Yokoi; Toshiya Furuta; Yasuhiro Abo; Hitoshi Chikamatsu; Takeshi Kondo; Yoshihiko Watanabe

Abstract There has been no report on T wave alternans (TWA) in patients with cardiac sarcoidosis. In this study, we investigated TWA in patients with cardiac sarcoidosis. Electrocardiographic recording for TWA was performed in 6 patients, using the CH2000 (Cambridge Heart). TWA was defined as positive in cases where alternans voltage of >1.9 μV and alternans ratio of >3.0 persisted more than 1 minute during exercise with ergometer with heart rate above 105 beats/min. TWA was positive in 3 patients, negative in 2 patients, and not determined in 1 patient. Arrhythmia was noted on Holter electrocardiogram in all 3 patients with positive TWA: sustained ventricular tachycardia in 1 patient and nonsustained ventricular tachycardia in 2 patients. Mean left ventricular ejection fraction in the 3 patients with positive TWA was 39.0%, whereas in the 2 patients with negative TWA it was 58.5%. A close relationship was suggested between TWA and severity of cardiac sarcoidosis.


Heart and Vessels | 2016

Prescription patterns of oral anticoagulants for patients with non-valvular atrial fibrillation: experience at a Japanese single institution

Manaka Tagaya; Daiji Yoshikawa; Yoshinori Sugishita; Fumi Yamauchi; Takehiro Ito; Tomohito Kamada; Masataka Yoshinaga; Daisuke Mukaide; Wakaya Fujiwara; Hiroatsu Yokoi; Mutsuharu Hayashi; Eiichi Watanabe; Junichi Ishii; Yukio Ozaki; Hideo Izawa


Journal of Cardiology | 2013

Role of the left atrial function on the pseudonormalization of the transmitral flow velocity pattern evaluated by two-dimensional tissue tracking technique

Daisuke Mukaide; Tomotsugu Tabata; Kosuke Kinoshita; Hiroatsu Yokoi; Wakaya Fujiwara; Osamu Inami; Yoshinori Sugishita; Gen Ukai; Masataka Yoshinaga; Tomohito Kamada; Masanori Nomura; Hideo Izawa


Circulation | 2003

Electrocardiographic Diagnosis of the Coronary Artery Culprit Site in Ischemic Heart Disease

Yasuhiro Abo; Hiroatsu Yokoi; Toshiya Furuta; Takahisa Kondo; Osamu Inami; Satoshi Kakizawa; Wakaya Fujiwara; Kenji Tamura; Masanori Nomura; Yoshihiko Watanabe

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Hideyuki Nosaka

Memorial Hospital of South Bend

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Masakiyo Nobuyoshi

Memorial Hospital of South Bend

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Hitoshi Yasumoto

Memorial Hospital of South Bend

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Naoya Hamasaki

MedStar Washington Hospital Center

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Sokei Mioka

Memorial Hospital of South Bend

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