Impact of diabetes on the benefits from everolimus-eluting stent as compared to first-generation drug-eluting stent in patients with ST elevation myocardial infarction

BACKGROUND: Drug-eluting stent has been shown to reduce the risk of repeated revascularization. However, as shown for first-generation drug-eluting stent, they may be counterbalanced by a potential higher risk of stent thrombosis, especially among ST-segment elevation myocardial infarction patients. In addition, diabetes has been shown to be an independent predictor of poor survival and repeated target vessel revascularization. No data have been reported so far on the long-term benefits and safety of new-generation drug-eluting stent in ST-segment elevation myocardial infarction according to diabetes. Therefore, the aim of this study was to evaluate whether diabetes may impact on the benefits from everolimus-eluting stent versus first-generation drug-eluting stent in patients undergoing primary angioplasty. METHODS: We combined data from two randomized trials (PaclitAxel or Sirolimus-Eluting Stent vs Bare-Metal Stent in Primary Angioplasty and randomized comparison of everolimus-eluting stents and sirolimus-eluting stents in patients with ST elevation myocardial infarction) including consecutive ST-segment elevation myocardial infarction patients admitted within 12 h of symptom onset undergoing primary angioplasty and stent implantation at a tertiary centre with 24-h primary percutaneous coronary intervention capability. Primary endpoint of this study was major adverse cardiac events at 3-year follow-up. Secondary endpoints were as follows: (1) death, (2) reinfarction, (3) definite or probable ST and (4) target vessel revascularization at 3-year follow-up. No patient was lost to follow-up. RESULTS: Our population is represented by 680 ST-segment elevation myocardial infarction patients treated with drug-eluting stent (180 enrolled in the PaclitAxel or Sirolimus-Eluting Stent vs Bare-Metal Stent in Primary Angioplasty trial, treated with first-generation drug-eluting stent, and 500 patients in the randomized comparison of everolimus-eluting stents and sirolimus-eluting stents in patients with ST elevation myocardial infarction, randomized to everolimus-eluting stent or sirolimus-eluting stent). Diabetes was observed in a total of 178 patients (26.1%) and associated with higher major adverse cardiac events, mortality, reinfarction, stent thrombosis and target vessel revascularization. Similar outcome was observed in terms of overall major adverse cardiac events, mortality, recurrent myocardial infarction, target vessel revascularization, with everolimus-eluting stent as compared to first-generation drug-eluting stent in both diabetic and non-diabetic patients, whereas everolimus-eluting stent was associated with a significantly lower rate of stent thrombosis only in diabetic patients (1.6% vs 9.6%, hazard ratio (95% confidence interval) = 0.15 (0.02-0.98), p = 0.04) whereas no difference was observed in non-diabetic patients. CONCLUSION: This study shows that among ST-segment elevation myocardial infarction patients undergoing primary angioplasty, diabetes is associated with a significantly worse outcome at 3-year follow-up. A similar outcome was observed between everolimus-eluting stent and first-generation drug-eluting stent in non-diabetic patients, whereas among diabetic patients everolimus-eluting stent was associated with a significant reduction in stent thrombosis.