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Biomedical subjects

Hiroshi Mabuchi

Publications and source records attributed to Hiroshi Mabuchi.

125 records · Page 7Linked to original sources
PubMed2002

Septal wall thinning and systolic dysfunction in patients with hypertrophic cardiomyopathy caused by a cardiac troponin I gene mutation.

BACKGROUND: Lysine 183 deletion in the cardiac troponin I gene is 1 of the mutations that causes hypertrophic cardiomyopathy (HCM). However, the clinical course and determinants of poor prognosis in patients with this mutation have not been well established. METHODS AND RESULTS: We analyzed 10 probands with HCM caused by this mutation and their family members. Forty-six of these 79 subjects were found to be carriers, and 33 were non-carriers. All non-carriers had a percent fractional shortening (%FS) of >25% at all ages. By contrast, 7 of 24 carriers >40 years of age had a %FS of <25%, and no carriers <40 years of age had a %FS of <25%. The change in interventricular septal thickness and the change in %FS were significantly correlated (R = 0.758; P =.0017). CONCLUSION: These results suggest that about 30% of patients with HCM caused by a lysine 183 deletion mutation in the cardiac troponin I gene have systolic dysfunction develop after 40 years of age, and that patients with this mutation whose interventricular septal thickness shows a serial decrease should be followed-up closely for development of systolic dysfunction.

Adult↗
PubMed2002

Large scale cohort study of the relationship between serum cholesterol concentration and coronary events with low-dose simvastatin therapy in Japanese patients with hypercholesterolemia.

Hyperlipidemia is a well-established risk factor for primary coronary heart disease (CHD). Although simvastatin is known to lower serum lipid concentrations, the protective effect of such lipid-lowering therapy against primary CHD has not been established in Japanese patients with hypercholesterolemia. The Japan Lipid Intervention Trial was a 6-year, nationwide cohort study of 47,294 patients treated with open-labeled simvastatin (5-10 mg/day) and monitored by physicians under standard clinical conditions. The aim of the study was to determine the relationship between the occurrence of CHD and the serum lipid concentrations during low-dose simvastatin treatment. Simvastatin reduced serum concentrations of total cholesterol (TC), low-density lipoprotein- cholesterol (LDL-C) and triglyceride (TG), by 18.4%, 26.8% and 16.1% on average, respectively, during the treatment period. The risk of coronary events was higher when the average TC concentration was > or =240 mg/dl and the average LDL-C concentration was > or =160 mg/dl. The incidence of coronary events increased in the patients with TG concentration > or =300 mg/dl compared with patients with TG concentration <150 mg/dl. The high-density lipoprotein cholesterol (HDL-C) inversely correlated with the risk of coronary events. The J-curve association was observed between average TC or LDL-C concentrations and total mortality. Malignancy was the most prevalent cause of death. The health of patients should be monitored closely when there is a remarkable decrease in TC and LDL-C concentrations with low-dose statin. A reasonable strategy to prevent coronary events in Japanese hypercholesterolemic patients without prior CHD under low-dose statin treatment might be regulating the serum lipid concentrations to at least <240 mg/dl for TC, <160 mg/dl for LDL-C, <300 mg/dl for TG, and >40 mg/dl for HDL-C.

Adult↗
PubMed2002

Large scale cohort study of the relationship between serum cholesterol concentration and coronary events with low-dose simvastatin therapy in Japanese patients with hypercholesterolemia and coronary heart disease: secondary prevention cohort study of the Japan Lipid Intervention Trial (J-LIT).

Hyperlipidemia is primarily implicated in the progression of coronary heart disease (CHD) and its treatment is essential for patients with a history of CHD. Statins such as simvastatin, the lipid-lowering agents, are well-known for their ability to normalize patient's serum lipid levels. The Japan Lipid Intervention Trial study of simvastatin is the first nationwide investigation of the relationship between serum lipid levels and the development of CHD in Japanese patients with hypercholesterolemia. Of 5,127 patients, exclusively with a history of documented CHD at enrollment, 4,673 were treated with open-labeled simvastatin at an initial dose of 5-10 mg/day and were monitored for 6 years. The risk of coronary events tended to be higher in patients with a serum total cholesterol (TC) > or =240 mg/dl compared with total cholesterol <240 mg/dl. The concentration of low-density lipoprotein cholesterol (LDL-C) positively correlated and that of high-density lipoprotein cholesterol (HDL-C) inversely correlated with the risk of CHD. Each 10 mg/dl decrease in LDL-C and each 10 mg/dl increase in HDL-C concentration reduced the risk of CHD by 8.0% (95% confidence interval 3.8-12.0) and 28.3% (95% CI 13.9-40.3), respectively. A reasonable therapeutic strategy to reduce CHD progression in patients with prior CHD under low-dose statin treatment might be regulating the serum LDL-C concentration to at least <120 mg/dl and HDL-C >40 mg/dl, respectively.

Adult↗
PubMed2002

Perfusable tissue index obtained by positron emission tomography as a marker of myocardial viability in patients with ischemic ventricular dysfunction.

In areas of severe asynergy, the clinically important task is to identify functionally recoverable myocardium. Fourteen patients with asynergy were investigated by H2(15O) dynamic positron emission tomography imaging before revascularization. Regional myocardial blood flow (MBF) was determined and the water-perfusable tissue fraction (PTF) for each region of interest and the total anatomical tissue fraction (ATF) were estimated. The PTF/ATF was analyzed as the water perfusable tissue index (PTI). Asynergy was defined as segments with wall motion more than 2SD below than that of a normal population. An increase of >0.8SD in anterior wall segments with asynergy and an increase of >0.6 SD in inferior wall asynergy were defined as significant improvements of wall motion indicative of viable myocardium. Fifteen segments with wall motion abnormalities less than -2SD and 10 control segments were identified; 7 segments recovered and 8 segments did not. MBF was similar in both groups of segments before revascularization (0.78 +/- 0.27 vs 0.73 +/- 0.18 ml min-(-1) x g(-1), NS). The PTI in the recovered segments was significantly higher than that in the unimproved segments (0.734 +/- 0.058 vs 0.592 +/- 0.038, p<0.0001) and was similar to that of the control segments. After revascularization, the PTI correlated with the SD of wall motion (p<0.05, r=0.58). PTI may be a good predictor of contractile recovery after revascularization.

Aged↗
PubMed2002

Effects of gender on the number of diseased vessels and clinical outcome in Japanese patients with acute coronary syndrome.

It has been reported that women with acute myocardial infarction (AMI) have a higher short-term mortality rate than men, but the reason is unclear and it is not known if it also applies to unstable angina pectoris (UAP). In addition, most previous studies have not presented angiographic findings. In the present study, the findings from 1,408 patients with AMI (group A: 361 women, 1,047 men) and 332 patients with UAP (group B: 103 women, 229 men) who underwent coronary angiography within 30 days of onset were analyzed. In both groups, the women were older and had a higher rate of hypertension and a lower rate of smoking than the men. There was no significant difference in Killip class or the number of diseased vessels between the women and men in both groups. Interventions (coronary angioplasty and coronary artery bypass grafting) were performed less frequently in the women than in the men (87.2% vs 91.8%, p=0.04) in group A, but not in group B (80.6% vs 81.2%, NS). In both groups, the overall mortality rate during hospitalization was higher in women than in men (group A: 14.4% vs 7.4%, p<0.0001, group B: 7.8% vs 1.7%, p=0.007). Multivariate analysis revealed that female gender was an independent predictor of in-hospital mortality in group B (odds ratio (OR): 6.4, 95% confidence interval (CI) 1.1-37.0, p=0.04), but not in group A (OR: 1.7, 95%CI 0.98-2.9, p=0.06). The independent predictors of in-hospital mortality, other than female gender were age, prior congestive heart failure, prior cerebrovascular disease and a higher Killip class in group A, and in both groups a higher number of diseased vessels. In conclusion, Japanese women with acute coronary syndromes present with similar angiographic findings and hemodynamics, but have a higher in-hospital mortality than male patients. Our results suggest that older age may be a potential explanation for the higher in-hospital mortality in women with AMI, but female gender itself may be an important predictor for it among those with UAP.

Acute Disease↗
PubMed2002

Spontaneous development of left ventricular aneurysm in a patient with untreated cardiac sarcoidosis.

A young adult patient with untreated sarcoidosis spontaneously developed a left ventricular (LV) aneurysm in the anterolateral free wall. Single-photon emission computed tomography (SPECT) using Gallium-67 clearly demonstrated widespread abnormal uptake, including the LV aneurysm. Thallium-201 SPECT revealed a perfusion defect in the anterolateral wall, and abnormal uptake of technetium-99m pyrophosphate was seen, especially in the borders of the defect lesion.

Adult↗
PubMed2002

Difference in coronary blood flow dynamics between patients with hypertension and those with hypertrophic cardiomyopathy.

We studied twelve patients with hypertensive left ventricular hypertrophy (LVH), 10 patients with hypertrophic cardiomyopathy (HCM) and 10 control subjects to examine the differences in coronary blood flow (CBF) dynamics between patients with hypertensive LVH and those with HCM. All subjects had normal coronary arteriograms. Measurements of CBF using Doppler Flo-Wire were performed at rest, and after infusions of acetylcholine and papaverine. The baseline CBF was significantly increased in both hypertensive LVH patients and HCM patients compared to that noted in control subjects (64.1+/-36.9, 80.0+/-38.1, 32.3+/-8.0 ml/min, respectively, p<0.01). Coronary flow reserve and endothelium-dependent vasodilatation were significantly lower in hypertensive LVH patients and HCM patients than in control subjects, but there was no significant difference between the hypertensive LVH and HCM patients themselves. In contrast, the diastolic/systolic velocity ratio at baseline was significantly lower in hypertensive LVH patients than in HCM patients (1.53+/-0.40, 6.31+/-7.50, p<0.05). Although CBF and coronary flow reserve correlated positively and negatively, respectively, with left ventricular mass index (r=0.51, -0.59, respectively), the diastolic/systolic velocity ratio at baseline did not show a significant correlation to left ventricular mass index. In conclusion, the diastolic/systolic velocity ratio differed between hypertensive LVH and HCM patients, independent of left ventricular mass. These results suggest that the difference of phasic pattern of CBF may be essential for coronary circulation in patients with hypertensive LVH and in those with HCM.

Adult↗
PubMed2002

Oxidative stress correlates with left ventricular volume after acute myocardial infarction.

It has been suggested that oxidative stress may play a role in the pathophysiology of heart failure. However, little is known about the clinical relationship between oxidative stress and left ventricular dilatation after acute myocardial infarction (AMI). We prospectively studied 28 consecutive patients, successfully treated with primary coronary angioplasty, after their first AMI. To evaluate oxidative stress, plasma oxidized low-density LDL levels (U/mL) were measured serially 1 day, 7 days, 14 days, 30 days, and 90 days after the onset of AMI using a specific sandwich enzyme-linked immunosorbent assay. Left ventriculography and coronary angiography were obtained in all patients 3 months after the AMI and infarct-related arteries were all patent. Peak plasma oxidized LDL levels were seen 7 days after AMI (after 1 day: 14.7+/-1.5, 7 days: 21.0+/-2.8, 14 days: 20.2+/-2.8, 30 days: 18.3+/-2.5, 90 days: 16.5+/-2.3 U/mL). Plasma oxidized LDL levels 7 days after AMI were significantly correlated with left ventricular end-diastolic volume (115+/-7 mL; r=0.54, P=0.0025) and end-systolic volume (58+/-5 mL; r=0.49, P=0.008) 3 months after the AMI. Moreover, they were also correlated with end-diastolic volume index (68+/-4 mL/m2, r=0.40, P<0.05). However, no correlation was seen between peak plasma oxidized LDL levels and ejection fraction. These findings suggest that oxidative stress may play an important role in the development and progression of left ventricular remodeling after AMI.

Angioplasty, Balloon, Coronary↗
PubMed2002

Acute urinary retention as an unusual manifestation of aseptic meningitis.

A formerly healthy 32-year-old woman was hospitalized for a closer examination of undiagnosed fever with mild headache. Despite lack of distinct findings on physical and laboratory examinations at admission, she suddenly developed anuresis due to acontractile neurogenic bladder. On the basis of her symptoms and the faint nuchal rigidity revealed later, as well as the results of cerebrospinal fluid analyses, a diagnosis of aseptic meningitis was eventually reached. While aseptic meningitis subsided within 3 weeks, about 10 weeks, including a 26-day period of anuria, was necessary for complete restoration of normal voiding function, necessitating intermittent self-catheterization. Acute urinary retention should be considered an uncommon but critical manifestation of aseptic meningitis.

Adult↗
PubMed2002

Report of the Japan Atherosclerosis Society (JAS) Guideline for Diagnosis and Treatment of Hyperlipidemia in Japanese adults.

This paper described the Guideline for Diagnosis and Management of Hyperlipidemias for Prevention of Atherosclerosis proposed by The Japan Atherosclerosis Society (JAS) Guideline Investigating Committee (1,995-2,000) under the auspices of the JAS Board of Directors. 1) The guideline defines the diagnostic criteria for serum total cholesterol (Table 1), LDL-cholesterol (Table 1), triglycerides (Table 4) and HDL-cholesterol (Table 7). It also indicates the desirable range (Table 1), the initiation levels of management (Table 2) and the target levels of treatment (Table 2) for total and LDL-cholesterol. 2) Though both total and LDL-cholesterol are shown as atherogenic parameter in the guideline, the use of LDL-cholesterol, rather than total cholesterol, is encouraged in daily medical practice and lipid-related studies, because LDL-cholesterol is more closely related to atherosclerosis. 3) Elevated triglycerides and low HDL-cholesterol are included in the risk factors, since no sufficient data have been accumulated to formulate the guideline for these two lipid disorders. 4) Emphasis is laid on evaluation of risk factors of each subject before starting any kind of treatment (Table 2). 5) This guideline is applied solely for adults (age 20-64). Lipid abnormalities in children or the youth under age 19, and the elderly with an age over 65 have to be evaluated by their own standard. 6) This part of the guideline gives only the diagnostic aspects of hyperlipidemias. The part of management and treatment will follow in the second section of the guideline that will be published in future.

Adult↗
PubMed2002

Risk factors for coronary heart disease in the Japanese--comparison of the background of patients with acute coronary syndrome in the ASPAC study with data obtained from the general population. Asia-Pacific Collaboration on CHD Risk Factor Intervention study.

The relative importance of metabolic risk factors for coronary heart disease (CHD) in the Japanese is assessed by comparing their prevalence in patients with acute coronary syndrome (ACS) enrolled in the Asia-Pacific Collaboration on CHD Risk Factor Intervention (ASPAC) study to that obtained by a serum lipid survey carried out in 1990 and also by comparing them to the ASPAC data from other countries and regions in this area. Hypertension was the most prevalent risk factor among Japanese patients with ACS as in the other countries and regions. The prevalence of obesity with a body mass index (BMI) of 30 or more was several times higher than that in the general population, although the rate was still much lower than in New Zealand and Singapore. In addition to hypercholesterolemia, hypertriglyceridemia and diabetes mellitus were frequently found in Japanese patients with ACS. When the prevalence of metabolic risk factors was compared between people with and without hypertension in the general population, the most remarkable difference was seen in BMI, followed by triglyceride and total cholesterol. These results indicate that hypertriglyceridemia and diabetes mellitus may be more important CHD risk factors in the Japanese population than LDL-cholesterol.

Coronary Disease↗
PubMed2002

Effect of pravastatin-induced LDL-cholesterol reduction on coronary heart disease and cerebrovascular disease in Japanese: Hokuriku lipid coronary heart disease study-pravastatin atherosclerosis trial (Holicos-PAT).

The purpose of Holicos-PAT was to investigate the efficacy of serum lipid lowering by pravastatin against coronary heart disease (CHD) and cerebrovascular disease (CVD) in the Japanese population. Hypercholesterolemic men and women (n = 2,232), aged 40-70 years, were followed up for 5 years, while they were receiving pravastatin (group P, n = 1,422) or only diet therapy (group C, n = 810). The primary endpoint was CHD (a composite of onset or worsening of angina pectoris, performing CABG or PTCA, non-fatal myocardial infarction, death from CHD including heart death or sudden death). The secondary endpoints were comprised of CVD, total mortality, variation of serum lipid and apoprotein levels, and a relationship between the LDL-C level and occurrence of CHD. For several reasons (proving to meet the exclusion criteria after registration, etc.), 1,290 cases of group P and 749 cases of group C were used as subjects for the primary analysis. The mean follow-up period was 4.5 years in group P and 4.2 years in group C for events of CHD. The mean LDL-C level (SD) in group P was 176 (29) mg/dl and decreased to 134 (29) mg/dl one year later. This effect continued during the follow-up period.CHD events occurred in 9.2/1000 patient-years for men and 2.4/1000 patient-years for women without a history of CHD.CHD events occurred in 55.3/1000 patient-years for men and 23.6/1000 patient-years for women with a history of CHD, which was 6 times higher in men and 10 times higher in women than in those without a history of CHD, respectively. The adjusted relative risk ratio of group P to group C for CHD events was 0.74 (95%CI: 0.47-1.19). In the patients with a history of CHD, the ratio was 0.55 (95%CI: 0.30-1.00). The effect was apparent in the patients with a history of CHD. The incidence of myocardial infarction in Japanese patients with hypercholesterolemia living in the Hokuriku district was apparently lower, than the worldwide incidence, indicative that pravastatin may have a tendency to inhibit the occurrence of events of arteriosclerotic disease.

Adult↗
PubMed2002

Clinical effects of rosuvastatin, a new HMG-CoA reductase inhibitor, in Japanese patients with primary hypercholesterolemia: an early phase II study.

The effects and tolerability of the new HMG-CoA reductase inhibitor rosuvastatin were assessed in 68 hypercholesterolemic Japanese patients (22 men and 46 postmenopausal women; age range 28-72 years) in a multicenter, double-blind, dose-ranging, early phase II study. Patients were randomized into three groups and received once-daily doses of 1, 2, or 4 mg rosuvastatin. Sixty evaluable patients (19 men and 41 women) with mean total cholesterol (TC) 294 mg/dl (7.60 mmol/l) and mean triglyceride (TG) 150 mg/dl (1.69 mmol/l) provided data in the efficacy analysis based on percentage changes in lipids at 4 and 8 weeks. All doses of rosuvastatin improved lipid parameters after both 4 and 8 weeks of therapy. On average, TC decreases were 22-29%, low-density lipoprotein cholesterol (LDL-C) decreases 32-42%, TG decreases 2% to 22%, and HDL-C increases 3-7%. There were no remarkable differences between efficacy at 4 and at 8 weeks, and dose-dependent reductions were noted for LDL-C, with 30, 39, and 42% decreases in the 1-, 2-, and 4-mg/ day dose groups, respectively, at 8 weeks. The drug was well tolerated over the 8 weeks of therapy. These preliminary results indicate that rosuvastatin is a potent cholesterol-lowering agent, capable of achieving marked reductions in LDL-C even at low doses.

Adult↗
PubMed2002

Heterogeneity of cardiac sympathetic nerve activity and systolic dysfunction in patients with hypertrophic cardiomyopathy.

UNLABELLED: Cardiac sympathetic nerve activity is changed in patients with hypertrophic cardiomyopathy (HCM). However, the relationship between heterogeneity of this activity and systolic left ventricular dysfunction in patients with HCM is not well established. This study was performed to evaluate the sympathetic nerve activity in various cardiac regions and to investigate the relationship between cardiac dysfunction and heterogeneity of the cardiac sympathetic nerve activity in patients with HCM. METHODS: Cardiac sympathetic nerve activity was evaluated in 25 patients with HCM and 10 control subjects using planar imaging and SPECT by 123I-metaiodobenzylguanidine (MIBG) myocardial scintigraphy. With planar 123I-MIBG imaging, the heart-to-mediastinum activity ratios (H/M), at early (20 min) and delayed (3 h) acquisition, and the washout rate were calculated. Polar maps of the left ventricular myocardium were divided into 20 segments, and the dispersion (maximal to minimal values) and SD of uptake and the washout rate in 20 segments were calculated. RESULTS: The early H/M did not differ between the 2 groups. The delayed H/M was significantly lower and the washout rate of the whole heart was significantly higher in the HCM group than those in the control group. In patients with HCM, the delayed H/M, early uptake dispersion, and SD of early uptake showed good correlation with the left ventricular end-diastolic and end-systolic dimensions and the percentage of fractional shortening. A stepwise regression analysis revealed that the SD of early uptake was a powerful determinant for the percentage of fractional shortening in patients with HCM. CONCLUSION: These results suggest that the heterogeneity of regional cardiac sympathetic nerve activity may be correlated with cardiac dysfunction in patients with HCM.

3-Iodobenzylguanidine↗
PubMed2002

[New guideline for the management of hyperlipidemia according to patient category and global risk chart].

Risk charts for predicting coronary heart disease(CHD) based on the Framingham Study are not valid for other ethnic people including Japanese, and no large scale prospective study exists which has examined the relationship between coronary risk factors and the incidence of CHD in Japan. The Japan Lipid Intervention Trial(J-LIT) is a 6-year prospective study of simvastatin therapy for mild hypercholesterolemia in a clinical setting. Major coronary events were observed in 336 patients in the primary prevention cohort(47,294) and 102 patients in the secondary prevention cohort(5,127) during the study period. Consequently we were able to create easy-to-use charts that predict the absolute risk of developing a coronary event based on determinable risk factors. Absolute risks were lower than predicted by the Framingham formula. The J-LIT charts demonstrate absolute and relative risks for primary and secondary coronary events in Japanese patients. Their use should help individualize risk factor management.

Coronary Disease↗
PubMedDate not supplied

Cardiac sympathetic nerve activity in patients with hypertrophic cardiomyopathy with malignant ventricular tachyarrhythmias.

BACKGROUND: Malignant ventricular tachyarrhythmia (VT) and sudden death are serious events in hypertrophic cardiomyopathy (HCM). However, the pathophysiology of this condition is not well understood. The objective of this study was to evaluate the relationship between cardiac sympathetic nerve activity and the occurrence of VT in HCM patients. Methods and results We studied iodine 123 metaiodobenzylguanidine scintigraphy and 24-hour ambulatory electrocardiographic monitoring in 44 HCM patients, 15 with VT (group A) and 29 without VT (group B). With planar I-123 metaiodobenzylguanidine imaging, the heart-to-mediastinum ratio for early and delayed acquisition and washout rate were calculated. Polar maps of left ventricular myocardium were divided into 20 segments, and the SD of uptake and washout rate in 20 segments were calculated as indices of regional variation. The global washout rate was significantly higher in group A than in group B (26.8 +/- 6.4% vs 17.4 +/- 5.7%, P <.0001), although other parameters including heterogeneity indices did not differ. The logistic multiple regression analysis also determined that washout rate was the most powerful predictor of VT in patients with HCM. CONCLUSIONS: The occurrence of malignant VT in HCM may be associated with global cardiac sympathetic nerve activity rather than with the heterogeneity of this activity.

3-Iodobenzylguanidine↗