Impact of Insulin-Requiring diabetes mellitus on effectiveness of reperfusion and outcome of patients undergoing primary percutaneous coronary intervention for acute myocardial infarction

The relation between diabetes mellitus (DM) and outcome was assessed in a series of 1,061 patients with acute myocardial infarction (AMI) who underwent primary percutaneous coronary intervention (PCI). The efficacy of reperfusion was assessed by ST-segment resolution analysis. Of 1,061 patients, 166 had DM (15.6%), and 84 had insulin-requiring DM (51% of DM patients). The 6-month mortality rate was 26% in insulin-requiring DM patients, 7% in non-DM patients, and 4% in non–insulin-requiring DM patients (p <0.001). The early ST-segment resolution rate was lower in insulin-requiring DM patients (52%) compared with the other DM patients (78%) and non-DM patients (76%; p <0.001). Multivariate analysis showed insulin-requiring DM to be independently related to the risk for death (hazard ratio 1.94, 95% confidence interval 1.17 to 3.22, p = 0.009). Insulin-requiring DM is a strong predictor of mortality in patients who undergo PCI for AMI, and this relation may be explained by a less effective myocardial reperfusion despite the mechanical restoration of normal epicardial flow in most patients.