Myocardial infarction in Malmö during the 10-year period 1963--1972

The independent roles of diet and serum lipids in the 20th-century rise and decline of coronary heart disease mortality

Risk factors are causally related to coronary heart disease (CHD), but in widely varying historic, geographic, socioeconomic, and individual relationships. Serum cholesterol is only one of many risk factors that, even when considered together in prospective studies, account for well under half of the CHD incidence. It is neither primarily regulated by the diet nor significantly related to it. Many findings discordant with widespread beliefs about a causal role of the diet in CHD are reviewed. It may be concluded that dietary fats are largely not responsible for relationships of serum cholesterol to CHD, or for its 20th-century rise and decline.

Declining trend in mortality after myocardial infarction

All patients under 60 years of age who were discharged from hospital after a first myocardial infarction between 1968 and 1977 in Göteborg were followed for a minimum of 24 months. The patients were unselected, and treatment was standardised. The patients were divided into five two yearly cohorts, and the prognostic comparability and mortality of these cohorts were assessed. There was a reduction in the two year mortality rate after discharge during the 10 year period. Small baseline differences between the cohorts were controlled by multivariate methods, and a subsequent analysis showed that there was a declining trend in mortality between 1968 and 1977. A higher tendency among smokers to give up smoking and a lower prevalence of angina pectoris could explain only part of the reduction in mortality. A small number of patients underwent a coronary bypass operation; the slight increase in the number of operations during the period cannot, however, account for the reduced mortality. Most of the patients in the later cohorts were treated with beta blockers, and this is the most likely explanation for the majority of the decline in mortality.

Increasing incidence and mortality from myocardial infarction in Stockholm county

A study was undertaken to examine trends in the incidence and mortality of myocardial infarction in Sweden. All cases (n = 19908) of myocardial infarction diagnosed in the population of Stockholm county during 1974-80 were identified by means of the cause of death register and the inpatient care register. Information on patients at risk was obtained from the civil registration system. The relative risk of developing, or dying of, myocardial infarction in one specific year, compared with the average for the whole period, was taken as the basis for describing the trends. For men in Stockholm the incidence as well as the mortality was appreciably increased; the annual increase in incidence was 3% and in mortality 4%. There were no signs of decreasing lethality. For women there was an appreciable increase in incidence; for mortality the result was less specific but was compatible with an increase. The observed increases in incidence and mortality appeared to be real and were probably not due to an increasing tendency for patients to seek hospital treatment or for doctors to make the diagnosis. The reason for the increase is unknown.

Characteristics of males with myocardial infarction below age 40

All cases of initial myocardial infarctions (MI) diagnosed among men below age 40 in Göteborg during 1970-1977 have been studied. The cases have been compared with a random sample from the general population in Göteborg with respect to socio-economic factors and conventional risk factors. The MI-cases showed a special socio-economic pattern prior to the infarction and were more often single and of foreign origin, had more previous sickness benefit days and were more often registered for alcohol abuse than contemporaries in the general population. Moreover, the surviving MI-cases were found to be heavily burdened with the conventional risk factors smoking, cholesterolemia and high blood pressure.

Current strategies for explaining the decline in ischemic heart disease mortality

Mortality from ischemic heart disease has declined sharply since the mid 1960's in the United States and several other industrialized nations. The causes of this decline have thus far not been established. Six major strategies for investigating determinants of ischemic heart disease mortality trends are discussed in this review: (1) analyses of mortality data; (2) morbidity surveillance; (3) surveillance of change in medical care; (4) surveillance of cardiovascular risk factors; (5) social and ecological surveillance; (6) experimental and quasi-experimental community approaches. The rationale, problems and limitations of each are discussed.