Impact of diabetes on long-term survival after acute myocardial infarction- Comparability of risk with prior myocardial infarction

OBJECTIVE - To determine the effect of diabetes on long-term survival after acute myocardial infarction and to compare its effect with that of a previ ous myocardial infarction. RESEARCH DESIGN AND METHODS - In a prospective cohort study, we followed 1, 935 patients hospitalized with a confirmed acute myocardial infarction at 4 5 U.S. medical centers between 1989 and 1993, as part of the Determinants o f Myocardial Infarction Onset Study. Trained interviewers performed chart r eviews and face-to-face interviews with all patients. We analyzed survival using Cox proportional hazards regression to control for potentially confou nding factors. RESULTS - Of the 1,935 patients, 320 (17%) died during a mean follow-up of 3.7 years. A total of 399 patients (21%) had previously diagnosed diabetes. Diabetes was associated with markedly higher total mortality in unadjusted (hazard ratio [HR] 2.4 95% Cl 1.9-3.0) and adjusted (1.7; 1.3-2.1) analyse s. The magnitude of the effect of diabetes was identical to that of a previ ous myocardial infarction. The effect of diabetes was not significantly mod ified by age, smoking, household income, use of thrombolytic therapy, type of hypoglycemic treatment, or duration of diabetes, but the risk associated with diabetes was higher among women than men (adjusted HRs 2.7 vs. 1.3, P = 0.01). CONCLUSIONS - Diabetes is associated with markedly increased mortality afte r acute myocardial infarction, particularly in women. The increase in risk is of the same magnitude as a previous myocardial infarction and provides f urther support for aggressive treatment of coronary risk factors among diab etic patients.