Long-term mortality after primary percutaneous coronary intervention for ST-segment elevation myocardial infarction in patients with insulin-treated versus non-insulin-treated diabetes mellitus

We investigated the impact of preadmission diabetic status on long-term outcome in patients with ST-segment elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (PCI), to improve risk stratification. Between 1997 and 2007, 4,402 STEMI patients were admitted to our hospital and stratified as having insulin-treated diabetes mellitus (ITDM) (n=176), non-ITDM (NITDM) (n=354) and non-DM (n=3,872). Five-year mortality was significantly higher in patients with DM compared to non-DM (29% vs. 18%, p <0.01). After stratification for preadmission glucose-lowering therapy, five-year mortality was significantly higher in ITDM patients compared to NITDM (36% vs. 25%, p=0.01) and in NITDM patients compared to non-DM patients (25% vs. 18%, p <0.01). After adjustment for age and gender the mortality risk between patients with NITDM versus non-DM was comparable (HR: 1.1, 95% CI: 0.9-1.4, p=0.38), in contrast to patients with ITDM (HR: 1.9, 95% CI: 1.5-2.5, p <0.01) and ITDM versus NITDM (HR: 1.7, 95% CI: 1.2-2.4, p <0.01). After adjustment for all baseline characteristics, the results were comparable to the age and gender adjusted model. ITDM was a strong predictor for long-term mortality when compared to non-DM and NITDM. The mortality between patients without DM and NITDM was comparable after adjustment for age and gender