Similar decline in post-myocardial infarction mortality among subjects with and without diabetes

Data from the 1970s and 1980s suggest that the rate of mortality from coronary disease for patients with diabetes has changed less than that for patients without diabetes. We evaluated trends in post-myocardial infarction mortality and morbidity in patients with and without diabetes over a 7-year period from 1990 through 1997, when substantial changes occurred in the management of coronary disease.

All patients discharged with the primary diagnosis of acute myocardial infarction (MI) from any Veterans Affairs Medical Center in the country between October 1990 and September 1997 were identified. Demographic, comorbid conditions, inpatient, outpatient, mortality, and readmission data were extracted. Mortality, trends in mortality over time, revascularization, readmissions, and length of hospital stay for MI were compared for the group with diabetes and the group without diabetes. Independent predictors of survival using a Cox regression model were examined.

We identified 67,889 patients with MI, of whom 17,756 (26%) had diabetes. At 60 days post-MI, there was a 29% higher mortality rate in the group with diabetes (5.2% versus 4.0%, P < 0.001), which increased to 35% at 1 year (16.1% versus 11.9%, P < 0.001). Diabetes was independently associated with increased overall mortality. Age-adjusted 1-year post-MI mortality from 1991 to 1998 had a significant downward trend (4.9% decrease in odds of mortality per year, P < 0.001) regardless of diabetes status.

Patients with diabetes showed a trend toward declining 1-year post-MI mortality rate that was not significantly different from that seen in patients without diabetes. Further work needs to be done to narrow the gap between the two groups.