Publications by authors named "Keishi Saihara"

Unlabelled: Chronic heart failure (HF) has various phenotypes. It is accompanied by repeated hospitalizations over a long period. Therefore, accumulating long-term observational data of patients with various backgrounds is important to establish a prediction technology for the exacerbation of HF.

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Pulmonary hypertension (PH) is an important cause of morbidity in patients with connective tissue disease (CTD), and an early stage of PH could present as exercise-induced PH (EIPH). This study investigated the significant clinical indexes of EIPH in patients with CTD. We enrolled 63 patients with CTD who did not have PH at rest.

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: We evaluate the efficacy of anticoagulant administration for isolated distal deep vein thrombus (IDDVT), detected before orthopedic surgery. : The study included 32 patients diagnosed with IDDVT before orthopedic surgery in our hospital between October 2011 and October 2017. They were divided into two groups: the 'pre- and post-operative therapy group,' who were administered anticoagulants both pre- and post-operatively, and the 'post-operative therapy group,' who were administered anticoagulants only after surgery due to risk of bleeding judged by an orthopedic surgeon.

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Aim: The amount of contrast media and renal atheroemboli are risk factors for acute kidney injury after percutaneous coronary intervention (PCI). However, the chronic kidney injury after PCI has not been fully characterized. The purpose of this study was to investigate factors affecting renal function in the late phase after PCI by measuring serum Cystatin C (CysC).

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Background: Recent evidence suggests that atrial fibrillation (AF) adversely affects endothelial function. The goal of this study was to assess endothelial function in patients with AF before and after restoration of sinus rhythm by catheter ablation (ABL).

Methods: Reactive hyperemia peripheral arterial tonometry (RH-PAT) measurements reflecting endothelial function were conducted with Endo-PAT2000 (Itamar Medical, Caesarea, Israel) in 27 patients with persistent AF before ABL and in 21 control subjects with sinus rhythm (SR).

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Bilirubin can prevent oxidation of low-density lipoprotein (LDL) and may protect against atherosclerosis and coronary heart disease (CHD). The goal of this study was to characterize the relationship between bilirubin and CHD through measurements of bilirubin concentration, coronary endothelial function, and markers of oxidative stress, inflammation, and lipid/glucose metabolism. The study population consisted of 141 patients without CHD who underwent Doppler flow study.

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Aim: Bilirubin has antioxidant properties and may protect against atherosclerosis and coronary heart disease (CHD). Further, in patients with metabolic syndrome, hyperbilirubinemia is associated with attenuation of insulin resistance. The aim of the present study was to determine the relationship between serum bilirubin concentration and coronary endothelial function in overweight patients.

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An unhealthy lifestyle can increase the risk of cardiovascular disease. However, the mechanism by which lifestyle influences the development of cardiovascular disease remains unclear. Since coronary endothelial function is a predictor of cardiovascular prognosis, the goal of this study was to characterize the effect of enjoying hobbies on coronary endothelial function and cardiovascular outcomes.

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Aim: The aim of this study was to investigate the role of uric acid (UA) in coronary endothelial function via its effects on renal function, other coronary risk factors and asymmetric dimethylarginine (ADMA) in men and women.

Methods: The study population consisted of 194 consecutive patients (119 men and 75 women) without coronary artery disease. The relationships between UA and coronary endothelial function, estimated glomerular filtration rate (eGFR), ADMA or other biochemical or anthropometric parameters were investigated.

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Background: Previous studies showed that some parameters, including left atrium diameter and left atrium volume index (LAVI), predicted the success of sinus conversion. However, no previous studies have investigated the association of sinus conversion with LAVI and histopathological findings. This study was designed to investigate the relationship among LAVI, pathological assessment, and failure in sinus conversion after surgery for valvular atrial fibrillation (AF).

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Background: Although reconduction after pulmonary vein (PV) isolation is considered to play a key role in the recurrence of paroxysmal atrial fibrillation (AF), there have been few reports regarding the precise time course of early reconduction. Several studies have suggested that transient PV reconduction facilitated by adenosine may predict long-term AF recurrence. This study was designed to clarify the incidence and time course of early reconduction after PVI during the procedure and to confirm whether the use of ATP after a certain observation period was useful to detect early reconduction after PVI.

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Background: Toll-like receptors (TLRs) recognize pathogen-associated molecular patterns to initiate an innate immune response. We previously reported upregulation of TLR2 expression level on monocytes of stable angina pectoris patients with significant coronary artery disease (CAD) relative to control patients without significant CAD. In this study we aimed to determine whether high level of Toll-like receptor 2 (TLR2) is a risk factor for atherogenesis, independent of established risk factors including smoking, diabetes mellitus (DM), hypertension (HT), and hyperlipidemia (HL).

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Background: Hyperglycemia upon hospital admission in patients with acute myocardial infarction is associated with the no-reflow phenomenon after successful reperfusion, and increased mortality. However, the mechanism underlying this phenomenon remains unclear. Therefore, the aim of this study was to characterize coronary hemodynamics in a homogenous group of non-diabetic patients without coronary artery disease.

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The comparative long-term antianginal efficacy of long-acting nitrates versus calcium channel antagonists remains unclear. The goal of the present study was to compare the coronary endothelial cell function and coronary artery vasoconstriction between patients with normal or mildly diseased coronary arteries treated with long-acting nitrates or calcium channel antagonists. Forty-two patients suspected to have angina pectoris and with normal or mildly diseased coronary arteries underwent Doppler flow study of the left anterior descending coronary artery.

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Background: Previous studies have demonstrated that decreased levels of circulating adiponectin correlate with endothelial dysfunction in peripheral arteries. However, the relationship between adiponectin levels and endothelial function in coronary arteries remains unclear. The goal of the present study was to determine whether circulating adiponectin concentrations are a useful predictor of coronary endothelial function.

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Objectives: Toll-like receptors mediate the innate immune response triggered by pathogen-associated molecular patterns, and atherosclerosis can be considered a state of chronic inflammation whereby immune system cells accumulate within the intima of the arterial wall. The goal of this study was to determine the relation of Toll-like receptors to the extent and severity of coronary artery disease.

Methods: Angiographic vessel score and Gensini score were used to evaluate the extent and severity of coronary atherosclerosis.

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Effects of cibenzoline on coronary hemodynamics, especially systolic reversal flow, were assessed in a 53-year-old man with hypertrophic obstructive cardiomyopathy by coronary flow study using a Doppler guidewire. Intravenous administration of cibenzoline resulted in decreases in the pressure gradient (60 to 0mmHg) and systolic left ventricular pressure (162 to 126 mmHg), and an increase in systolic arterial pressure (102 to 132mmHg). Furthermore, the systolic reversal flow observed at baseline was markedly diminished following administration of cibenzoline.

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Background: Plasma levels of brain natriuretic peptide (BNP) correlate with left ventricular remodeling, but the relationship between BNP induction and coronary function remains unclear.

Objectives: The present study assessed BNP production in response to left ventricular enlargement and investigated the relationship between BNP production and coronary vasodilating function in patients with left ventricular remodeling.

Methods: Patients (n = 63) with normal or mildly diseased coronary arteries underwent Doppler flow study of the left anterior descending coronary artery.

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Background: Asynchronous electrical activation induced by right ventricular apex (RVA) pacing can cause various abnormalities in left ventricular (LV) function, particularly in the context of severe LV dysfunction or structural heart disease. However, the effect of RVA pacing in patients with normal LV and right ventricular (RV) function has not been fully elucidated. The aim of this study was to characterize the effects of RVA pacing on LV and RV function by assessing isovolumic contraction time and isovolumic relaxation time divided by ejection time (Tei index) and by assessing changes in plasma brain natriuretic peptide (BNP).

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Background: The relationship between coronary remodeling, shear stress and endothelial function remains unclear.

Objective: The present study investigated the effects of mechanical factors on structure and function of epicardial coronary arteries.

Methods: Patients (group 1: %area stenosis<40%, n=55; or group 2: %area stenosis>or=40%, n=17) with a discrete mildly stenotic lesion (%diameter stenosis<30%) underwent intravascular ultrasound examination of the left anterior descending coronary artery for determination of vessel area, lumen area, plaque area, cross-sectional areas at reference segments, and remodeling index (the ratio of vessel area at the culprit lesion to vessel area at the proximal reference site).

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This study assessed the impact of coronary vascular adaptive remodeling and coronary vascular reactivity on myocardial ischemia in patients with hypertension and left ventricular hypertrophy. Myocardial ischemia is associated with impaired endothelium-independent vasodilation of resistance coronary arteries and increased minimal coronary resistance. These changes may occur in association with lumen reduction caused by attenuated adaptive remodeling in response to plaque accumulation.

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Objectives: To characterize delayed restoration of coronary blood flow following successful percutaneous transluminal coronary angioplasty (PTCA).

Background: Delayed restoration of coronary blood flow following successful PTCA is common and likely the result of multiple factors. Temporary myocardial ischemia and dipyridamole administration both result in increased coronary blood flow, but by different mechanisms.

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Background: Compensatory enlargement of the coronary arterial wall has been described in the early stages of native atherosclerosis. However, little is known about the specific effect of aging on this adaptive process in atherosclerosis. The purpose of the current study was to characterize the effects of advancing age on vascular remodeling and endothelium-dependent and -independent coronary vasodilation in patients without coronary artery disease risk factors.

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This study evaluates the clinical usefulness of ST/HR slope derived from ST elevation on exercise to predict the improvement in regional wall motion following coronary revascularization in patients with healed myocardial infarction. We studied 58 patients with a diseased, infarct-related and single-vessel coronary artery. The decline calculated from the final 12 data points relating ST-segment elevation to heart rate during exercise were derived (ST/HR slope).

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