Publications by authors named "Youichi Takeyama"

Background: Statin therapy results in regression and stabilization of coronary artery plaques, and reduces the incidence of coronary artery disease. However, statin therapy does not effectively halt the accumulation of necrotic core in all patients. The purpose of the present study was to identify the predictors associated with necrotic core progression during statin therapy.

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Background: Diabetes mellitus (DM) accelerates plaque progression despite the use of statin therapy. The purpose of the present study was to evaluate the determinants of atheroma progression in statin-treated patients with DM.

Methods: Coronary atherosclerosis in nonculprit lesions in a vessel undergoing percutaneous coronary intervention (PCI) was evaluated using virtual histology intravascular ultrasound.

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Thin-cap fibroatheroma (TCFA) is the most common type of vulnerable plaque and is the precursor of plaque rupture. However, rupture of a TCFA is not the only mechanism underlying thrombus formation or acute coronary syndrome. Although statin therapy changes the composition of coronary artery plaques, the effects of statins, particularly different types of statins, on plaque phenotype have not been fully examined.

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Age is a well-established risk factor for cardiovascular disease. Recent trials using intravascular ultrasound (IVUS) have shown that lipid-lowering therapy with statins halts the progression or induces the regression of coronary artery plaques. However, impacts of age on coronary atherosclerosis and vascular response to statin therapy have not been fully evaluated.

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Aim: The TRUTH trial demonstrated that 8-month statin therapy alters the composition of coronary artery plaque using virtual histology (VH)-intravascular ultrasound (IVUS). The extended TRUTH study was conducted to evaluate the relationship between changes in coronary atherosclerosis and mid-term clinical outcomes and identify the factors associated with cardiovascular events.

Methods: Of 164 patients with angina pectoris who participated in the TRUTH trial, 119 subjects with analyzable IVUS data at both enrollment and the 8-month follow-up were enrolled and observed for at least two years.

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A low n-3 to n-6 polyunsaturated fatty acid (PUFA) ratio is associated with cardiovascular events. However, the effects of this ratio on coronary atherosclerosis have not been fully examined, particularly in patients treated with different types of statins. This study compared the effects of n-3 to n-6 PUFA ratios on coronary atherosclerosis in patients treated with pitavastatin and pravastatin.

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Although statin-induced regression in coronary atherosclerosis seems to be greater in patients with acute coronary syndrome than in those with stable coronary artery disease, no reports have examined this. The purpose of the present study was to compare the changes in coronary atherosclerosis in patients with stable versus unstable angina pectoris (AP). The effects of 8-month statin therapy on coronary atherosclerosis were evaluated using virtual histology intravascular ultrasound, and analyzable intravascular ultrasound data were obtained from 119 patients (83 patients with stable AP and 36 with unstable AP).

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Background: A low n-3 to n-6 polyunsaturated fatty acids (PUFAs) ratio is reported to be associated with cardiovascular events. However, the effects of statins on this ratio have not been fully examined.

Methods: A total of 101 patients with coronary artery disease, who were not receiving lipid-lowering therapy were randomly assigned to receive either 4 mg/day of pitavastatin or 20 mg/day of pravastatin.

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The specific cell surface markers on mesenchymal stem/progenitor cells (MSCs) have been poorly defined in vivo, but in one recent study, an MSC subpopulation was directly isolated from a CD271-positive fraction of human bone marrow cells. The aim of this study was to identify circulating CD271(+) MSCs in human peripheral blood and investigate whether the cells are mobilized after acute myocardial infarction (MI). A flow cytometric analysis identified CD45(low/-)CD34(+)CD271(+) cells in adult human peripheral blood.

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A low ratio of n-3 to n-6 polyunsaturated fatty acids has been associated with cardiovascular events. However, the effects of this ratio on coronary atherosclerosis have not been fully examined. The purpose of the present study was to evaluate the correlations between the n-3 to n-6 polyunsaturated fatty acid ratio and coronary atherosclerosis.

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Background: Patients with diabetes mellitus (DM) have a markedly increased incidence of adverse cardiovascular events, but the mechanisms have not been well-characterized.

Methods And Results: The TRUTH study evaluated the effects of 8-month statin therapy on coronary artery plaque composition using virtual histology intravascular ultrasound (IVUS). Analyzable IVUS data were obtained from 119 patients, including 50 DM patients.

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Background And Objectives: The aim of this study was to evaluate the effects of an L- and T-type calcium channel blocker (CCB) on 24-hour systolic blood pressure (24-hour SBP) and heart rate (24-hour HR) profiles in essential hypertensive patients.

Subjects And Methods: Thirty-seven consecutive patients were enrolled in this study. The 24-hour SBP and HR were recorded before and after treatment with efonidipine (L- and T-type CCB, 40 mg), after waking.

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Objective: Patients with diabetes mellitus (DM) and hypertension (HT) are at a high risk of coronary artery disease. However, the mechanisms underlying this have not been well characterized. The purpose of the present study was to evaluate the impacts of DM and HT on coronary atherosclerosis during statin therapy.

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Statin therapy produces regression of coronary artery plaques and reduces the incidence of coronary artery disease. However, not all patients show regression of coronary atherosclerosis after statin therapy. The purpose of the present study was to identify differences in clinical characteristics, serum lipid profiles, arterial remodeling, and plaque composition between patients with progression and those with regression of coronary atherosclerosis during statin therapy.

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Background: Systemic therapy with statin has been shown to lower the risk of coronary events; however, the in vivo effects of statin therapy on plaque volume and composition are less understood.

Methods: We conducted a prospective, open-labeled, randomized, multicenter study in 11 centers in Japan. A total of 164 patients were randomized to receive either 4 mg/d of pitavastatin (intensive lipid-lowering therapy) or 20 mg/d of pravastatin (moderate lipid-lowering therapy).

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Erythropoietin (EPO) has recently been shown to confer cardioprotective effects via angiogenesis and antiapoptosis. The administration of EPO after myocardial infarction (MI) reduces infarct size and improves cardiac function in small animals. The purpose of this study is to investigate the protective effects of EPO in porcine MI.

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Few reports have examined the effects of adult bone marrow multipotent stromal cells (MSCs) on large animals, and no useful method has been established for MSC implantation. In this study, we investigate the effects of MSC infusion from the coronary vein in a swine model of chronic myocardial infarction (MI). MI was induced in domestic swine by placing beads in the left coronary artery.

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Background: Erythropoietin (EPO) has been found to have anti-apoptotic and tissue protective effects on the myocardium. The aim of the present pilot study was to observe the safety and efficacy of EPO administration for patients with acute myocardial infarction (AMI).

Methods And Results: Patients admitted with AMI had all undergone successful percutaneous coronary intervention (PCI).

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Background: Pituitary adenylate cyclase-activating polypeptide (PACAP) is known as a cytoprotective polypeptide. PACAP and its receptors are expressed in the heart, but it is unclear whether PACAP exerts its protective effect on the myocardium in vivo. The aim of the present study was to investigate whether endogenous PACAP has a cardioprotective effect on Doxorubicin (Dox)-induced cardiomyopathy.

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Objective: We investigated the risk of upper gastrointestinal (UGI) bleeding and the protective effect of concomitant anti-secretory drugs during dual antiplatelet therapy administered following implantation of drug-eluting stents (DES) for coronary heart disease. Because proton pump inhibitors (PPIs) are reported to decrease the platelet inhibitory effects of clopidogrel, we also assessed cardiovascular outcomes in patients taking thienopyridine derivatives with or without anti-secretory drug.

Methods: We retrospectively analyzed 243 patients, who underwent DES implantation between January 2006 and December 2007 and were receiving dual anti-platelet therapy post-surgery.

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Coronary spasm is a risk factor for acute myocardial infarction and sudden cardiac death. This is a case of a young female patient with cardiopulmonary arrest induced by coronary spasm on arrival at our hospital. There has been no case that prolonged spontaneous attack was confirmed in multi-vessels.

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Background: Many clinical trials have shown that 3-hydroxy-3-methylglutaryl-conenzyme A reductase inhibitors (statins) can significantly reduce the incidence of coronary artery disease in both primary and secondary prevention. A recent study showed that aggressive lipid-lowering therapy with statins could achieve regression of coronary artery plaque evaluated with gray-scale intravascular ultrasound (IVUS). However, the actual changes in coronary artery plaque composition produced by statin therapy have not been well delineated.

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QT prolongation, a risk factor for arrhythmias, can result from genetic variants in one (or more) of the genes governing cardiac repolarization as well as intake of drugs known to affect a cardiac K(+) channel encoded by human ether-a-go-go-related gene (HERG). In this paper, we will report a case of drug-induced long QT syndrome associated with an H(1)-receptor antagonist, hydroxyzine, in which a mutation was identified in the HERG gene. After taking 75 mg of hydroxyzine for several days, a 34-year-old female began to experience repetitive syncope.

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