Endpoint Of Myocardial Infarction Research Articles

Myocardial infarction in Mexican-Americans and non-Hispanic whites. The San Antonio Heart Study.

Mexican-American men experience reduced cardiovascular mortality compared with non-Hispanic white men. There is no corresponding ethnic difference in cardiovascular mortality in women. The difference in men could result either from a lower incidence of cardiovascular disease or a lower case fatality rate among Mexican-Americans. Although the incidence of cardiovascular disease in Mexican-Americans is unknown, we have collected data on prevalence of myocardial infarction in 5,148 individuals examined in the San Antonio Heart Study, a population-based survey of cardiovascular disease conducted between 1979 and 1988 in Mexican-Americans and non-Hispanic whites aged 25-64 years. Myocardial infarction was assessed by Minnesota-coded electrocardiograms and by a self-reported history of a physician-diagnosed heart attack. For both end points, the age-adjusted prevalence of myocardial infarction was lower in Mexican-American men than in non-Hispanic white men. After adjustment for age and diabetes status (present/absent), the odds of a myocardial infarction, as defined by either criterion, was approximately one third lower in Mexican-American men than in non-Hispanic white men (p = 0.06). In women, the prevalence of both myocardial infarction end points was slightly higher in Mexican-Americans than in non-Hispanic whites, although neither of these differences was significant. Although the ethnic differences in prevalence in this study were not statistically significant, their pattern parallels the pattern in the mortality due to cardiovascular diseases. Therefore, the results support the hypothesis that the reduced cardiovascular mortality rate observed in Mexican-American men reflects a lower incidence of myocardial infarction rather than a reduced case fatality rate because the latter would result in a higher prevalence.

Morbidity, Mortality, and Quality of Life for Patients Treated With Levothyroxine

In a population study of 1462 middle-aged women initiated in 1968 and 1969 we identified 29 women treated with levothyroxine from 1 to 28 years. In a 12-year follow-up in 1980 and 1981 we investigated the subjects for end-point myocardial infarction, diabetes mellitus, stroke, cancer, and death (the status of 99.7% of the initial participants was established). The women treated with levothyroxine showed no increase in morbidity or mortality. Of the 24 women still receiving levothyroxine in 1980 and 1981, 22 had serum thyrotropin and triiodothyronine concentrations with-in reference limits. These individuals were compared with the 968 women from the population study having no history of thyroid disease, and appeared identical as to laboratory and clinical data, with the exception of a slightly higher body mass, taller stature, and lower serum cholesterol concentration. The treated group did not differ in a life quality estimate based on 19 questions regarding life satisfaction and sensory function. We conclude that the levothyroxine-treated woman suffers no side effects from her life-long therapy.

Morbidity, mortality, and quality of life for patients treated with levothyroxine

• In a population study of 1462 middle-aged women initiated in 1968 and 1969 we identified 29 women treated with levothyroxine from 1 to 28 years. In a 12-year follow-up in 1980 and 1981 we investigated the subjects for end-point myocardial infarction, diabetes mellitus, stroke, cancer, and death (the status of 99.7% of the initial participants was established). The women treated with levothyroxine showed no increase in morbidity or mortality. Of the 24 women still receiving levothyroxine in 1980 and 1981, 22 had serum thyrotropin and triiodothyronine concentrations within reference limits. These individuals were compared with the 968 women from the population study having no history of thyroid disease, and appeared identical as to laboratory and clinical data, with the exception of a slightly higher body mass, taller stature, and lower serum cholesterol concentration. The treated group did not differ in a life quality estimate based on 19 questions regarding life satisfaction and sensory function. We conclude that the levothyroxine-treated woman suffers no side effects from her life-long therapy. (<i>Arch Intern Med.</i>1990;150:2077-2081)

Clinical trials including an update on the Helsinki heart study

The incidence of myocardial infarction (MI), sudden death and other clinical manifestations of coronary heart disease can be reduced by lowering the blood cholesterol level. This is now well established by multiple clinical trials using a variety of interventions including diet and lipid-lowering drugs. Dietary studies in Los Angeles and in Oslo, Norway, have induced a reduction in blood cholesterol of between 10 and 15% with correlated reductions in coronary disease of 20 to 50%. Both niacin and clofibrate in separate cohorts demonstrated a significant reduction in new MI during 5 years of treatment in the Coronary Drug Project. Similar reductions in new MI occurred in the World Health Organization Study with clofibrate. However, in this trial and different from all other trials, mortality in the drug-treatment group actually increased. This finding remains unexplained. In the more recent Lipid Research Clinics Coronary Primary Prevention Trial using the bile acidbinding resin cholestyramine, only a 9% reduction in total cholesterol resulted in a highly significant reduction in the major end points—MI and sudden death—as well as in other secondary end points, including the need for coronary artery bypass graft surgery, ischemic changes on exercise electrocardiography and new-onset angina. Recently, another primary prevention trial using gemfibrozil produced a similar reduction in total cholesterol but a much more significant increase in high-density lipoprotein cholesterol. The reduction in coronary heart disease was in excess of 34% and was strongly related to both low-density lipoprotein cholesterol reduction and high-density lipoprotein elevation. Combination drug studies have produced larger reductions in total cholesterol. In the Stockholm Heart Study, niacin and clofibrate produced a statistically significant reduction in total mortality in patients who had had recent Ml. Similarly, in men who had undergone coronary artery bypass graft surgery, the combination of niacin, colestipol and diet produced strong evidence of a reduced rate of progression of arteriosclerotic lesions as demonstrated by coronary angiography. This study, conducted at the University of Southern California, was the Cholesterol-Lowering Atherosclerosis Study. It also produced evidence of lesion regression in some patients. Although these studies have been carried out primarily in middle-aged men, the older segments of these populations have appeared to do as well with regard to disease prevention as the younger members of the cohorts. We can now treat patients with high blood cholesterol levels both before and after manifestation of coronary disease with significant assurance that beneficial effects will accrue. Additional studies with newer and more powerful lipid-lowering agents are needed, as are studies in women and the elderly.

Distribution of adipose tissue and risk of cardiovascular disease and death: a 12 year follow up of participants in the population study of women in Gothenburg, Sweden.

A longitudinal population study of 1462 women aged 38-60 was carried out in Gothenburg, Sweden, in 1968-9. In univariate analysis the ratio of waist to hip circumference showed a significant positive association with the 12 year incidence of myocardial infarction, angina pectoris, stroke, and death. The association with incidence of myocardial infarction remained in multivariate analysis and was independent of age, body mass index, smoking habit, serum cholesterol concentration, serum triglyceride concentration, and systolic blood pressure. The relation between the ratio of waist to hip circumference and the end points of myocardial infarction, angina pectoris, stroke, and death was stronger than for any other anthropometric variable studied.

Lipid Research Clinics Program

To the Editor.— The LRC-CPPT cholesterol study1seems to have been impeccably done, but the results show just a slight decrease in serum cholesterol level and a small reduction in CHD end point. To be significant, the treatment and placebo groups had to be exactly identical, and this fact is uncertain since the study was not a primary prevention trial as claimed. The serum cholesterol level in the cholestyramine-treated group was decreased 34.4 mg/dL, merely 19.9 mg/ dL less than in the placebo group. The CHD death and/or myocardial infarction end point was 8.1% in the treated group and 9.8% in the placebo group. Only 32 more cases (out of 1,900) reached the end point in the placebo group compared with the treatment group. The authors believe that the lower incidence of CHD events seen in the cholestyramine group could not be attributed to factors other than cholesterol lowering,

Community surveillance for coronary heart disease: The Framingham Cardiovascular Disease Survey: Comparisons with the Framingham Heart Study and previous short-term studies

It appears likely that intervention trials on a community scale against one or more coronary heart disease risk factors will begin in the near future. Prerequisite to the evaluation of the effectiveness of these trials is the accurate determination of coronary heart disease incidence rates. The Framingham Cardiovascular Disease Survey was undertaken to test the hypothesis that a short-term surveillance study of a defined population can generate accurate incidence rates for at least some categories of cardiovascular disease and that these rates are comparable with those obtained by longitudinal survey of the same population. In conjunction with the 1970 U.S. census, a 1 year survey was made of all new coronary heart disease events occurring in the town of Framingham, Mass. Surveillance was performed by several methods that were intentionally overlapping. During the study period, 244 coronary heart disease events occurred. Despite the relatively small size of the population, many of the well established epidemiologic characteristics of this disease were evident. The rates obtained by the cardiovascular disease survey were comparable with those obtained by the Framingham Heart Study, for the harder end points of myocardial infarction and death from coronary heart disease, but much smaller for the softer end point of angina pectoris, especially in women. These data and those from similar studies indicate that periodic short-term surveillance studies of target populations of major intervention programs can provide an economic method of generating incidence data for the evaluation of the impact of such programs on myocardial infarction and death from coronary heart disease.