Effect of enoxaparin versus unfractionated heparin in diabetic patients with ST-elevation myocardial infarction in the Enoxaparin and Thrombolysis Reperfusion for Acute Myocardial Infarction Treatment–Thrombolysis In Myocardial Infarction study 25 (ExTRACT–TIMI 25) trial

Background Patients with diabetes mellitus (DM) are at higher risk for complications after ST-elevation myocardial infarction (STEMI) than patients without DM. Potent antithrombotic therapies may offer particular benefit for these high-risk patients and must be balanced against the potential for increased bleeding. Methods We performed a prospectively planned analysis of efficacy and safety in patients with DM among 20 479 patients with STEMI treated with fibrinolysis and randomized to a strategy of enoxaparin (up to 8 days) or unfractionated heparin (UFH) (48 hours) in ExTRACT-TIMI 25. Results Patients with DM (n = 3060) were older and more likely to be women and to present with heart failure ( P < .0001 for each) than those without DM. After adjustment for the TIMI Risk Score, sex, and renal function, patients with DM were at 30% higher risk for death or myocardial infarction (MI) by 30 days (ORadj 1.29, 95% CI 1.14-1.46). Among patients with DM, the enoxaparin strategy reduced mortality (9.5% vs 11.8%, relative risk [RR] 0.81, 95% CI 0.66-0.99), death/MI (13.6% vs 17.1%, RR 0.80; 95% CI 0.67-0.94), and death/MI/urgent revascularization (16.0% vs 19.7%, RR 0.81, 95% CI 0.70-0.94). The enoxaparin strategy was associated with a trend toward higher major bleeding (2.6% vs 1.6%, RR 1.63, 95% CI 0.99-2.69). Taking efficacy and safety into account, the enoxaparin strategy offered superior net clinical benefit (death/MI/major bleed, 14.8% vs 18.0%, RR 0.83, 95% CI 0.70-0.97) compared with UFH in patients with DM. Conclusions In a subgroup analysis, a reperfusion strategy including enoxaparin significantly improved outcomes compared with UFH among high-risk STEMI patients with DM undergoing fibrinolysis.