Myocardial infarction in patients with diabetes mellitus.

The occurrence of diabetes mellitus and its complications and prognosis in an unselected consecutive series of patients with myocardial infarction (MI) was studied. Out of 341 patients 81 (24%) had diabetes. Comparisons were made between patients with and without diabetes. Age was higher and female sex more common among patients with diabetes. A considerable proportion of patients with diabetes were on digitalis when admitted (51%) compared to 20% of those without. Ventricular tachyarrhythmias requiring treatment did not differ between the two groups. High-degree AV-block was considerably more common among patients with diabetes (19%) than those without (7%; P less than 0.001). Mortality was higher in diabetic than in non-diabetic patients both during the hospital phase (25%, vs. 16%; P less than 0.02) and during one year of follow-up (53% vs. 28%; P less than 0.001). Diabetes was an independent prognostic risk factor for death (P less than 0.01). Fatal reinfarction was more common among diabetic patients (30%) than those without (14%; P less than 0.05). In conclusion diabetics with MI have a poor prognosis despite improvements in coronary care. The high late mortality is to a large extent related to a high proportion of fatal reinfarctions.