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

Aims: 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. Methods and results: 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. Conclusions: 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.