The rate of coronary heart disease (CHD) mortality in eastern Finland has been the highest in the world. The official mortality statistics suggest, however, that is has declined by 60% during the past 20 years. The aim of the present study was to examine the contributions of incidence, recurrence, and case fatality of coronary events to the trends in CHD mortality in three areas of Finland.
Population-based myocardial infarction registers have been operating in the provinces of North Karelia and Kuopio in eastern Finland and the Turku/Loimaa area in southwestern Finland from 1983 to 1992. During this 10-year period, each suspected coronary event in persons 35 to 64 years of age was evaluated for registration. Of these, 13,566 fulfilled the criteria of myocardial infarction or coronary death. Almost one fourth (22.4%) of the coronary events were sudden, out-of-hospital deaths. Among men, the average change in mortality was -7.1% per year (95% confidence interval, -8.4% to -5.8%) in North Karelia, -5.0% per year (-7.0% to -3.0%) in Kuopio, and -4.9% per year (-8.2% to -1.6%) in Turku/Loimaa. Among women, the corresponding changes were -5.6% (-11.1% to -0.1%), -4.4% (-8.1% to -0.7%), and -8.1% (-13.0% to -3.2%). In eastern Finland, the decline in CHD mortality was due to a decline in recurrent coronary events but also in the incidence of first coronary events, whereas in southwestern Finland, the decline in case-fatality rate had the major role.
The decline in CHD mortality rate in Finland appears to be the result of a successful combination of primary and secondary prevention measures and improvements in acute coronary care.