A brief review of epidemiological studies on ischemic heart disease in Japan

Coronary artery stenosis in Japanese people living with HIV-1 with or without haemophilia

An extremely high prevalence (12.2%) of moderate-to-severe coronary artery stenosis (CAS) was documented in asymptomatic Japanese haemophiliacs living with HIV-1 (JHLH) in our previous study. The cause of this phenomenon remains unknown. We conducted the CAS screening in people living with HIV-1 without haemophilia (PLWH without haemophilia) to compare the prevalence of CAS in JHLH and PLWH without haemophilia and to identify the risk factors including inflammation markers. Ninety-seven age-matched male PLWH without haemophilia who consulted our outpatient clinic between June and July 2021 were randomly selected, and 69 patients who provided informed consent were screened for CAS using coronary computed tomography angiography (CCTA). The number of JHLH cases was 62 in this study. The prevalence of moderate (> 50%) to severe (> 75%) CAS was significantly higher in JHLH [14/57 (24.6%) vs. 6/69 (8.7%), p = 0.015], and the ratio of CAS requiring urgent interventions was significantly higher [7 (12.3%) vs. 1 (1.4%), p = 0.013] in JHLH than in PLWH without haemophilia. Among the inflammatory markers, serum titres of intercellular adhesion molecule-1 (p < 0.05) and interleukin-6 (p < 0.05) in JHLH were significantly higher than those in PLWH without haemophilia. Although some patient demographics were different in the age-matched study, it might be possible to speculate that intravascular inflammation might promote CAS in JHLH.

Effectiveness of Endovenous Radiofrequency Ablation for Elderly Patients with Varicose Veins of Lower Extremities

Objective: The purpose of this study was to evaluate safety and effectiveness of endovenous radiofrequency ablation (RFA) for elderly patients. Materials and Methods: We enrolled 140 patients (194 limbs) who underwent RFA for varicose veins of lower extremities. Patients were divided into two groups; elderly patients (more than 75 years old, E-group, n=36) and young patients (under 75 years old, Y-group, n=104), and perioperative data were analyzed and compared between two groups. Results: In E-group, there were more than patients with hypertension, ischemic heart disease, malignant tumor, and cerebrovascular disease. A partial recanalization was observed in only one limb (0.6%) in Y-group. Endovenous heat induced thrombosis (EHIT) was identified four limbs (2.8%) in Y-group and two limbs (4.1%) in E-group. All EHITs were class 1 by Kabnick classification, and they disappeared within one month after interventions, without antithrombotic therapy. No other major complications were observed. There were no significantly differences for preoperative mean venous clinical severity scores (VCSS) (Y : E=4.84 : 4.47) and postoperative VCSS (Y : E=1.16 : 1.19, 0.35 : 0.58, 0.15 : 0.06, 0.05 : 0.06 at 1, 3, 6, 12 months after) in both groups. Conclusion: RFA for elderly patients is a safe and effective strategy for varicose veins of lower extremities.

Risk charts illustrating the 10-year risk of myocardial infarction among residents of Japanese rural communities: the JMS Cohort Study

BACKGROUND

Risk charts that depict the absolute risk of myocardial infarction (MI) for each combination of risk factors in individuals are convenient and beneficial tools for primary prevention of ischemic heart disease. Although risk charts have been developed using data from North American and European cardiovascular cohort studies, there is no such chart derived from cardiovascular incidence data obtained from the Japanese population.

METHODS AND RESULTS

We calculated and constructed risk charts that estimate the 10-year absolute risk of MI by using data from the Jichi Medical School (JMS) Cohort Study--a prospective cohort study which followed 12 490 participants in 12 Japanese rural communities for an average of 10.9 years. We identified 92 cases of a clinically-certified MI event. Color-coded risk charts were created by calculating the absolute risk associated with the following conventional cardiovascular risk factors: age, sex, smoking status, diabetes status, systolic blood pressure, and serum total cholesterol.

CONCLUSIONS

In health education and clinical practice, particularly in rural communities, these charts should prove useful in understanding the risks of MI, without the need for cumbersome calculations. In addition, they can be expected to provide benefits by improving existing risk factors in individuals.

The value of combining serum alanine aminotransferase levels and body mass index to predict mortality and medical costs: a 10-year follow-up study of National Health Insurance in Shiga, Japan

BACKGROUND

Evidence suggests that the predictive value of serum alanine aminotransferase (ALT) levels for prognosis, measured by indices such as all-cause mortality and medical costs, may be modified by body mass index (BMI). However, the relationship between serum ALT and BMI has not been satisfactorily elucidated.

METHODS

Four thousand, five hundred and twenty-four community dwelling Japanese National Health Insurance beneficiaries, 40-69 years old, were classified into five categories according to their serum ALT levels (IU/L) (ALT<20, 20< or =ALT<30, 30< or =ALT<40, 40< or =ALT<50 and 50< or =ALT) and followed for 10 years. Hazard ratios for all-cause mortality, with reference to the lowest serum ALT category, and medical costs per person were evaluated for each serum ALT category after analyzing interactions between serum ALT levels and BMI for all-cause mortality and for medical costs.

RESULTS

A significant interaction between serum ALT levels and BMI was observed. In participants below the median BMI, positive, graded relationships were identified between serum ALT levels and all-cause mortality as well as between serum ALT levels and personal medical costs. The multivariate-adjusted hazard ratio in the "50< or =ALT" category showed an approximately 8-fold increase. However, in the participants at or above the median BMI, no significant relationships between serum ALT levels and all-cause mortality or personal medical costs were identified.

CONCLUSIONS

In these Japanese participants, the predictive value of serum ALT levels for prognosis was more evident if BMI was taken into account. A combination of high serum ALT levels and below median BMI was associated with excess mortality and medical costs.

Treatment of Hyperlipidemia from Japanese Evidence

The treatment of hyperlipidemia is aimed at preventing cardiovascular disease (CVD) and coronary heart disease (CHD). As the incidence of CHD in Japan is about one-third lower and that of stroke is two-fold higher compared to Western countries, and the doses of lipid-lowering drugs used in foreign randomized controlled clinical trials (RCTs) are much higher than in general use in Japan, it remains unclear whether the results of RCTs conducted in Western countries could be extrapolated to Japanese patients. Recently, two major large-scale, prospective, RCTs in Japanese hypercholesterolmic patients, the Management of Elevated Cholesterol in the Primary Prevention of Adult Japanese (MEGA) study and the Japan EPA Lipid Intervention Study (JELIS), have been reported. Japanese epidemiological studies and Japanese clinical studies are reviewed. The evidence suggests that hypercholesterolemia, hypertriglyceridemia, and low HDL-cholesterol are strongly associated with increased CHD risk. Lipid-lowering medication shows beneficial effects even in low-risk populations; however, the data did not support that lower cholesterol is better. The safety and efficacy of hyperlipidemia treatment in Japanese patients are discussed.

A large-scale prospective cohort study on the current status of therapeutic modalities for acute myocardial infarction in Japan: rationale and initial results of the HIJAMI Registry

BACKGROUND

In Western countries, several multicenter collaborative studies on acute myocardial infarction (AMI) have provided much information about this disease. In Japan, on the other hand, there have been few cohort studies in which a sufficient number of Japanese patients with AMI were registered during a short period. This fact explains the absence of a database from which strategies for treating Japanese patients with AMI could be established. The purpose of this study was to build a comprehensive database on Japanese patients with AMI to elucidate their characteristics.

METHODS

Between January 1999 and June 2001, we consecutively registered all patients with AMI who were admitted to 17 participating medical institutions, including The Heart Institute of Japan, Cardiology (HIJC), Tokyo Women's Medical University. A standardized case report form was used to register all the patients.

RESULTS

A total of 3,021 consecutive patients was registered (2,136 men, 70.7%; 885 women, 29.3%) with a median age of 69 years [59, 77]. Among the patients, there were 851 elderly individuals (28.2%) > or = 76 years and 1102 patients with diabetes (36.5%). On index electrocardiogram, ST-elevation myocardial infarction was observed in 2,392 patients (79.2%). Within 24 hours after the onset of AMI, coronary angiography was conducted for 2,177 patients (72.1%). Primary percutaneous coronary intervention and coronary thrombolysis were conducted for 1,755 (58.1%) and 491 patients (16.3%), respectively, and percutaneous coronary intervention or coronary artery bypass grafting was additionally carried out in 303 patients. By the time of discharge, coronary angiography and coronary artery bypass grafting were performed in 2,659 (88.0%) and 137 patients (4.5%), respectively. During initial hospitalization, 285 patients died and the overall inhospital mortality rate was 9.4%. During hospitalization, cardiogenic shock and cardiac rupture were observed in 6.1% and 2.8% of the patients, respectively. The inhospital mortality rate is still high in patients with AMI with such mechanical complications and in elderly patients.

CONCLUSION

In our prospective cohort, we showed that Japanese patients with AMI could be characterized as (1) having a disease severity comparable with values observed in Western populations and (2) receiving early reperfusion therapy by PCI, which was used widely and safely, but nevertheless (3) exhibiting a high inhospital mortality rate. Our data indicate that further improvements in therapy for AMI in elderly patients and for AMI with mechanical complications are essential in Japan.

Culture and symptom reporting at menopause

The purpose of the present paper is to review recent research on the relationship of culture and menopausal symptoms and propose a biocultural framework that makes use of both biological and cultural parameters in future research. Medline was searched for English-language articles published from 2000 to 2004 using the keyword 'menopause' in the journals--Menopause, Maturitas, Climacteric, Social Science and Medicine, Medical Anthropology Quarterly, Journal of Women's Health, Journal of the American Medical Association, American Journal of Epidemiology, Lancet and British Medical Journal, excluding articles concerning small clinical samples, surgical menopause or HRT. Additionally, references of retrieved articles and reviews were hand-searched. Although a large number of studies and publications exist, methodological differences limit attempts at comparison or systematic review. We outline a theoretical framework in which relevant biological and cultural variables can be operationalized and measured, making it possible for rigorous comparisons in the future. Several studies carried out in Japan, North America and Australia, using similar methodology but different culture/ethnic groups, indicate that differences in symptom reporting are real and highlight the importance of biocultural research. We suggest that both biological variation and cultural differences contribute to the menopausal transition, and that more rigorous data collection is required to elucidate how biology and culture interact in female ageing.

Three-Year Follow-up Results of Angiographic Intervention Trial Using an HMG-CoA Reductase Inhibitor to Evaluate Retardation of Obstructive Multiple Atheroma (ATHEROMA) Study

BACKGROUND

The cardiovascular event rate in Japanese populations is strikingly lower than that in Caucasian populations and it has been postulated that this difference might be because of variations in atherosclerosis progression in patients with coronary artery disease (CAD). However, the rate of angiographically assessed progression and its response to statins has not been well described in Japanese patients.

METHODS AND RESULTS

The angiographic intervention trial using an HMG-CoA reductase inhibitor to evaluate the retardation of obstructive multiple atheroma (ATHEROMA) study was a multicenter, randomized, controlled clinical trial investigating the effects of pravastatin on coronary atherosclerosis in Japanese patients with CAD using quantitative coronary angiography. In total, 361 patients with mild to moderate elevated serum total cholesterol concentrations (195-265 mg/dl) received diet only (n = 179) or diet plus pravastatin 10-20 mg/dl (n = 182). Over 3 years, low-density lipoprotein-cholesterol in the pravastatin group decreased by 19.5% (p < 0.0001). A per-patient analysis showed that minimum lumen diameter increased by 0.034+/-0.17 mm in the pravastatin group, but decreased by 0.006+/-0.16 mm in the diet only group (p = 0.04). The mean difference between the treatment groups was 0.040 mm (95% confidence interval 0.020, 0.070 mm).

CONCLUSION

The ATHEROMA study indicates that pravastatin 10-20 mg/day for 3 years improves hyperlipidemia, then suppresses progression and induces regression of focal coronary atherosclerosis in Japanese CAD patients with elevated serum cholesterol.

Is angiotensin-converting enzyme inhibitor useful in a Japanese population for secondary prevention after acute myocardial infarction? A final report of the Japanese Acute Myocardial Infarction Prospective (JAMP) study

BACKGROUND

Although angiotensin-converting enzyme (ACE) inhibitors have appeared to be useful for secondary prevention after acute myocardial infarction (AMI) in Western countries, that has not been confirmed in non-western countries. We investigated whether ACE inhibitors improve survival rates in patients who have survived an AMI in Japan.

METHODS

A randomized controlled trial, the first non-pharmaceutical company-supported multicenter trial of a medication in Japan, was carried out in 48 institutions from 1993 to 2000. A total of 888 of 1163 patients with AMI were eligible for the full analysis set (FAS). The mean patient age was 62 years, and 78% of patients were men. Subjects were randomized to 2 groups; 422 received ACE inhibitors and 466 did not receive ACE inhibitors. The primary end point was combined cardiac events, which was defined as cardiac or non-cardiac death, recurrent non-fatal myocardial infarction, coronary revascularization, and hospitalization because of worsening angina or congestive heart failure. The mean follow-up period was 5.8 years.

RESULTS

There were no significant differences in the 2 groups in baseline data. During the follow-up period, 3 patients were lost to follow-up. With Kaplan-Meier analysis, the annual rate of total cardiac events was 32% in both groups. After adjustment for clinical baseline data, ACE inhibitor administration was not revealed with Cox regression analysis to have a significant prognostic effect in our study.

CONCLUSION

We did not show a significant improvement in outcome with ACE inhibitor administration in subjects who survived after AMI in a Japanese study population. Further evaluations with a larger population or in subjects who are at a higher risk for AMI are necessary to confirm our findings.

Past history of obesity (overweight by WHO criteria) is associated with an increased risk of nonfatal acute myocardial infarction: a case-control study in Japan

BACKGROUND

Obesity is an important risk factor for the occurrence of coronary artery disease (CAD) in Western countries and furthermore, it often coexists with other CAD risk factors such as hypertension, dyslipidemia and diabetes mellitus. However, it is uncertain whether obesity is a CAD risk factor in Japan because Japanese are relatively thin on average.

METHODS AND RESULTS

The CAD risk associated with obesity (body mass index > or =25.0) 10 years before as well as at the time of the survey was assessed in a case - control study of acute myocardial infarction (AMI), which compared 660 AMI patients aged 40-79 years and 1,277 community controls, matched to each case by sex, year of birth, and residence. The prevalence of current obesity did not show any material difference between cases and controls, but compared with controls, past obesity was much more frequent in cases. Even after controlling for other CAD risk factors, past obesity was associated with a 2-fold increase in the risk of AMI. Past obesity was associated with an increased risk of AMI even without current obesity.

CONCLUSION

Past obesity is a CAD risk, even after weight reduction.

Role of prehypertension in the development of coronary atherosclerosis in Japan

BACKGROUND

Hypertension is an important risk factor of coronary heart disease. A new guidelines for hypertension prevention and management in The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure in the United States recommended lifestyle modification or medical treatment for subjects with prehypertension. However, whether prehypertension increases the risk of coronary atherosclerosis in the Japanese population is still unknown.

METHODS

A cross-sectional study in a clinical setting was conducted. The subjects were 705 patients (417 males and 288 females) aged 30 years and older who underwent a first-time coronary angiography for suspected or known coronary heart disease at 5 major cardiology departments in the Fukuoka metropolitan area between September 1996 and August 1997.

RESULTS

Compared to subjects with normal blood pressure, those with prehypertension had an increased risk of coronary atherosclerosis even after adjusting for other factors.

CONCLUSION

Prehypertension may be an important clinical entity which requires treatment in the Japanese population.

Lifestyle, Serum Lipids and Coronary Artery Disease:Comparison of Japan with the United States

Westernization of the Japanese lifestyle has been steadily progressing, and the percent energy intake as fat has increased 3.8 fold over the past 50 years. Although the serum cholesterol (C) level has also increased, the death rate due to coronary artery disease (CAD) is not increasing. Consumption of dietary fat in the United States (US) is decreasing and serum C levels are also decreasing. Although the death rate due to CAD is markedly decreasing in men and women in the US, it is still 4 times higher than that of Japanese. The percent energy intake as fat in Japanese migrants to the US (Japanese-American: JA) lies between that of native Japanese and US populations, and their C values are higher than those of native Japanese. Compared with native Japanese, JA showed a significant increase in carotid intima-media wall thickness, and deaths from CAD are also higher than those of Japanese in Japan. Although the death rate due to CAD has not yet increased in Japan, Japanese have the potential for further progression of atherosclerosis and increasing CAD.

Hypertension control and medication increase in primary care

Over half of treated patients with hypertension are not well controlled. However, little is known about physicians' prescribing behaviour for these patients. Our objective was to clarify whether physicians increase antihypertensive medication in patients with poorly controlled hypertension and what characteristics are predictors of medication increase. This was a retrospective cohort study by surveying medical records in primary care clinics in Tochigi, Japan. Twenty-nine of 79 randomly selected physicians agreed to select 20 consecutive hypertensive patients. This resulted in 547 patients (women 60%; mean (s.d.) age, 68 (12) years) who had blood pressure measurements taken in 1998 and prescription of antihypertensive medication in 1998 and 1999. Mean (s.d.) systolic/diastolic blood pressure was 142 (12)/81 (9) mm Hg and the percentage of patients in good control (<140/90 mm Hg), fair (140-159/90-94) and poor (> or =160/95) were 42%, 47%, and 11%, respectively. Physicians increased medication in 28% of poorly controlled patients (95% confidence interval (CI), 17-41%), which was more than those in fair (12%, 95%CI 8-16%) or good control (7%, 95%CI 4-12%). Multivariate logistic regression analysis showed that systolic and diastolic blood pressures were positively, and the number of kinds of antihypertensive medications and the age of the physician were negatively, associated with an increase in medication. In conclusion, primary care physicians did not increase antihypertensive medication adequately for patients with uncontrolled hypertension. Attempts to understand and to change physicians' prescription behaviour could reduce the burden of uncontrolled hypertension among treated hypertensive patients.

Effects of pravastatin on exercise electrocardiography test performance and cardiovascular mortality and morbidity in patients with hypercholesterolemia: Lipid Intervention Study in Kyoto

The long-term effects of the 3-hydoxy-3-methyl-glutaryl coenzyme A reductase inhibitor, pravastatin, on exercise electrocardiography (ECG) test performance and cardiovascular mortality and morbidity were compared with those of conventional lipid-lowering drugs in hypercholesterolemic patients with no history of myocardial infarction or stroke. One thousand two hundred and seventeen patients were randomly assigned with mean serum cholesterol, triglyceride, high-density lipoprotein (HDL) cholesterol, and low-density lipoprotein (LDL) cholesterol levels of 6.98 +/- 0.91mmol/L, 2.08 +/- 1.87mmol/L, 1.38 +/- 0.44mmol/L, and 5.07 +/- 1.14 mmol/L, respectively, and received either pravastatin at a dose of 10-20mg/day (group P) or one of the conventional lipid-lowering drugs such as fibrates, nicotinic acid, and probucol (group C). The numbers of patients available for analysis in groups P and C were 305 and 278 at year 1, 261 and 216 at year 2, 206 and 184 at year 3, 159 and 122 at year 4, and 103 and 81 at year 5. Over the 3.2 year mean follow-up period, the reduction in serum LDL cholesterol levels was significantly greater (p<0.01) in group P (-24.3%) than in group C (-16.0%). Serum HDL cholesterol levels increased in group P (+11.6%), but decreased in group C (-0.3%) (p<0.01). There were no significant differences in the rate of patients who exhibited ischemic changes to exercise ECG test (ischemic responders) between the 2 groups. Coronary heart diseases (CHD) occurred in 6 patients in group P and 13 in group C; pravastatin significantly reduced CHD risk (reduction rate 0.369; 95% confidence interval 0.140-0.970; p<0.05). No significant differences existed between the treatment groups in terms of the number of strokes (group P, 6; group C, 7) or deaths unrelated to CHD (group P, 3; group C, 2). Although pravastatin did not improve the proportion of ischemic responders on exercise testing, it reduced CHD risk and serum LDL cholesterol levels more significantly than conventional lipid-lowering drugs without adversely affecting the risk of stroke and non-CHD death in hypercholesterolemic patients.