Acute Myocardial Infarction in Diabetes Mellitus

iabetes mellitus affects '6% of the US population but is present in as many as 30% of patients hospitalized with acute coronary syndromes. It has been recognized for some time that diabetics experience a greater mortality during the acute phase of myocardial infarction (MI) and a higher morbidity in the postinfarction period (see recent reviews in References 1 and 2). Before the advent of coronary care as we know it today, mortality among diabetic patients in MI was reported to be as high as 40%3 and at least double the mortality rate in patients without diabetes. More extensive coronary artery disease, additional cardiovascular risk factors, and other end-organ disease were thought to be largely responsible for this major difference in outcome. Current treatment of acute MI derived from large clinical trials has dramatically improved survival in both nondiabetic and diabetic patients. However, despite these improvements, diabetes still doubles the case- fatality rate. In the GUSTO-1 angiography substudy report,4 this twofold increase in relative risk of 30-day mortality persisted even after adjustment for the factors cited above. What is this "diabetic factor"? It is in this context that new information on this topic must be evaluated. In the December 16, 1997, issue of Circulation, the GISSI-3 investigators compare the effect of early administration (within 24 hours of admission) of lisinopril in patients with and without diabetes mellitus in MI.5 Compared with placebo, lisinopril dramatically reduced both 6-week and 6-month mortality in diabetics versus nondiabetics (6 weeks, 30% versus 5% and 6 months, 20% and 0%, respectively). Furthermore, the incidence of drug-related adverse effects was similar between the two groups within the blood pressure and renal function parameters used in that study. This experience, along with the subgroup analyses of SAVE6 and TRACE,7 should firmly establish an ACE inhibitor as part of the regimen for the diabetic patient with MI. In a recent meta-analysis of ACE inhibitor trials in acute MI, only a 6% relative mortality reduction (without regard to the presence or absence of diabetes mellitus) was found with early drug administration.8