Efficacy of Drug-Eluting Stents in Diabetic Patients Admitted with ST-Elevation Myocardial Infarctions Treated with Primary Percutaneous Coronary Intervention

Background: Diabetic patients show higher adverse ischemic event rates and mortality when undergoing percutaneous coronary intervention (PCI) in acute myocardial infarctions. Therefore, diabetic patients might benefit even more from modern-generation drug-eluting stents (DES). The aim of the present study was to compare adverse ischemic events and mortality rates between bare-metal stents (BMS) and DES in diabetic patients admitted with ST-elevation-myocardial infarction (STEMI) with non-diabetic patients as the control group. Methods: All STEMI patients undergoing emergency PCI and stent implantation documented between 2006 and 2019 in the Bremen STEMI registry entered the analysis. Efficacy was defined as a combination of in-stent thrombosis, myocardial re-infarction or additional target lesion revascularization at one year. Results: Of 8356 patients which entered analysis, 1554 (19%) were diabetics, while 6802 (81%) were not. 879 (57%) of the diabetics received a DES. In a multivariate model, DES implantation in diabetics compared to BMS was associated with lower rates of in-stent thrombosis (OR 0.16, 95% CI 0.05–0.6), myocardial re-infarctions (OR 0.35, 95%CI, 0.2–0.7, p < 0.01) and of the combined endpoint at 1 year ((ST + MI + TLR): OR 0.31, 95% CI 0.2–0.6, p < 0.01), with a trend towards lower 5-year mortality (OR 0.56, 95% CI 0.3–1.0, p = 0.058). When comparing diabetic to non-diabetic patients, an elevation in event rates for diabetics was only detectable in BMS (OR 1.78, 95% CI 0.5–0.7, p < 0.01); however, this did not persist when treated with a DES (OR 1.03 95% CI 0.7–1.6, p = 0.9). Conclusions: In STEMI patients with diabetes, the use of DES significantly reduced ischemic event rates and, unlike with BMS, adverse ischemic event rates became similar to non-diabetic patients.