Objectives. This study was designed to assess outcome in patients with diabetes who received thrombolytic therapy and to determine whether differences in angiographic characteristics may account for the worse outcome observed in diabetic patients.

Background. Patients with diabetes are known to have a worse outcome after acute myocardial infarction than that of patients without diabetes.

Methods. Clinical and angiographic characteristics of the 148 patients with diabetes and the 923 patients without diabetes in the Thrombolysis and Angioplasly in Myocardial Infarction (TAMI) trials were examined and analyzed.

Results. Patients with diabetes tended to be older (median age 59 vs. 56 years) and to have a higher incidence of hypertension and hyperlipidemia and a lower incidence of cigarette smoking. Patients with diabetes had significantly more severe anatomic disease (66% vs. 46% had multivessel disease, p < 0.0001), similar global left ventricular ejection fraction (49% vs. 51%) and worse noninfarct zone ventricular function (−0.13 vs. 0.32 SD/chord, p = 0.02) than that of nondiabetic patients. Angiographic patency rates at 90 min after thrombolytic therapy were similar in patients with and without diabetes (initial 90-min patency 71% vs. 70%). Diabetic patients had nearly twice the in-hospital mortality rate (11% vs. 6%, p < 0.02) and a higher incidence of pulmonary edema (11% vs. 4%, p = 0.001). Diabetic women had an especially high in-hospital mortality rate (21%). No retinal hemorrhages were observed. Although diabetes as an unadjusted variable was predictive of in-hospital (p < 0.02) and long-term (p = 0.003) mortality, after adjustment for baseline clinical and angiographic characteristies, diabetes was not found to have an independent influence on mortality.

Conclusions. Patients with diabetes after myocardial infarction have a worse outcome than that of patients without diabetes despite similar rates of infarct vessel patency. However, diabetes was not found to be an independent risk factor for increased mortality. These findings suggest that diabetes itself is not a major risk factor for poor early outcome after thrombolytic therapy for myocardial infarction; rather, the secondary effects such as more extensive coronary artery disease account for the worse outcome.