Second-generation versus first-generation drug-eluting stents for the treatment of patients with acute coronary syndromes and obstructive coronary artery disease

Abstract

Randomized trials and registries have shown that drug-eluting stents (DES) have an overall better performance than bare-metal stents in patients treated in the setting of both ST-segment and non-ST-segment elevation acute coronary syndromes, mainly by reducing restenosis. Whether or not the use of newer second-generation devices (vs. first-generation DES) differs in these high-risk patients remains to be determined. In a single-centre prospective registry, 3266 patients underwent a percutaneous coronary intervention with at least one DES from January 2003 to December 2009. Of these, 1423 (43.6%) were treated in the setting of an acute coronary syndrome, using either first-generation-only DES [paclitaxel or sirolimus; n=923 (64.9%)] or second-generation-only [zotarolimus or everolimus; n=500 (35.1%)]. The occurrence of death from any cause, nonfatal myocardial infarction or target vessel failure (composite primary endpoint) was compared between these two groups; repeat revascularization of the index stented lesion and definite stent thrombosis [according to the academic research consortium (ARC) definition] were assessed as isolated secondary outcomes. At a median follow-up of 598 days (interquartile range 453-1206), the incidence of death was 10.7% (152), 136 patients (9.6%) had a new myocardial infarction and target vessel failure events occurred in 147 patients (10.3%). Disparity in the follow-up duration was accounted for by considering only the 1-year major adverse cardiac event rate (n=161; 11.3%). After adjustment for baseline characteristics using a Cox proportional hazard model, we could not find a significant difference in the incidence of the composite primary endpoint at 1-year between first-generation (10.8%) and second-generation DES (12.2%) [hazard ratio (HR): 1.1; 95% confidence interval (CI): 0.82-1.57, P=0.463], nor in the occurrence of repeat target lesion revascularization (3.6 vs. 4.4%; HR 1.35; 95% CI 0.77-2.34; P=0.293). In a per patient analysis, at 1 year, ARC-definite ST was documented in 1.0% of patients treated with second-generation DES versus 2.8% in those treated with first-generation DES (corrected HR 0.36; 95% CI 0.14-0.94; P=0.037), owing mostly to a higher difference in late ST. Our results suggest that both first-generation and second-generation DES seem to be similarly effective in patients undergoing a percutaneous coronary intervention in the setting of acute coronary syndromes. However, newer second-generation devices may offer potential advantages because of a significantly lower incidence of ARC-definite ST.