Impact of Diabetes on Mortality After the First Myocardial Infarction

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.