Impact of Diabetes on Mortality After the First Myocardial Infarction

Abstract

OBJECTIVE To study diabetic and nondiabetic patients with their first myocardial infarction to determine overall 1-year mortality, out-of-hospital mortality, 28-day mortality of hospitalized patients, and 1-year mortality of 28-day survivors. RESEARCH DESIGN AND METHODS This study—based on the FINMONICA Myocardial Infarction Register, a part of the Finnish contribution to the WHO MONICA Project (World Health Organization Multinational Monitoring of Trends and Determinants of Cardiovascular Disease)—covered coronary heart disease (CHD) deaths and acute CHD events occurring during hospitalization among residents of Finland aged 25–64 years in three geographically defined areas. The study population comprised 620 diabetic and 3,445 nondiabetic patients who had their first myocardial infarction during the years 1988–1992. RESULTS The age- and area-adjusted mortality rates and hazard ratios (HRs) for diabetic versus nondiabetic patients (95% CI) were as follows: The 1-year mortality rate was 44.2% in diabetic men and 32.6% in nondiabetic men (HR, 1.38; 1.18−1.61) and 36.9% in diabetic women and 20.2% in nondiabetic women (HR, 1.86; 1.40−2.46); the out-of-hospital mortality rate was 28.3% in diabetic men and 22.4% in nondiabetic men (HR, 1.25; 1.03−1.52) and 10.4% in diabetic women and 11.0% in nondiabetic women (HR, 0.95; 0.58−1.54); the 28-day mortality rate of hospitalized patients was 14.4% in diabetic men and 8.8% in nondiabetic men (HR, 1.58; 1.15−2.18) and 21.7% in diabetic women and 7.8% in nondiabetic women (HR, 2.60; 1.71−3.95); and the 1-year mortality rate of 28-day survivors was 9.6% in diabetic men and 5.0% in nondiabetic men (HR, 1.97; 1.25−3.12) and 10.7% in diabetic women and 2.5% in nondiabetic women (HR, 4.17; 2.05−8.51). CONCLUSIONS The high mortality rate of diabetic patients after their first myocardial infarction and the high proportion of out-of-hospital deaths in this group imply that vigorous primary and secondary preventive measures should become an integral part of their medical care.