Coronary heart disease attack rate, incidence and mortality 1975-1994 in Göteborg, Sweden

Data from the Göteborg myocardial infarction register were used to investigate trends in attack rate, incidence of non-fatal myocardial infarction and mortality from coronary heart disease in persons aged 64 and below during the period 1975-1994.

Myocardial infarction was defined according to strict criteria which remained the same throughout the study period. Attack rate and incidence were 3-5 times higher among men than women. The ratio of recurrent infarcts out of all attacks increased with increasing age and was 14%, 20% and 24% for men aged 35-44, 45-54, and 55-64, respectively. Corresponding rates for women were 8%, 14%, and 22%, respectively. Both attack rate and incidence decreased significantly by 2.1-3.9% per year during the study period for most age groups. The 28-day fatality rate (hospitalized as well as non-hospitalized cases) tended to decline, but significantly so only in the oldest men. The same was true for 28-day fatality among hospitalized patients. The majority of all coronary heart disease deaths occurred outside hospital in people unaware they had coronary heart disease. Mortality from coronary heart disease decreased by 2.0-6.8% per year during the study period. In-hospital treatment of myocardial infarction with intravenous beta-blockers followed by oral treatment, nitroglycerin and thrombolytics increased during the study period. Coronary surgery and angioplasty were used in less than 5% of patients during the study period, but increased substantially in 1994.

Coronary heart disease and mortality in ages below 65 years are now decreasing in Sweden. Decreasing short-term mortality is almost certainly due to more efficient treatment in hospital, but as the majority of coronary heart disease deaths occur outside hospital and in people unaware they have coronary heart disease, primary prevention is still very important.