Abstract 16775: Efficacy and Safety of a Thinner-strut Silicon Carbide-coated Cobalt Chromium Bare-metal Stent Compared to a Thin-strut Uncoated Cobalt Chromium Bare-metal Stent in Large Vessel Stenting: Insights From Two Prospective Randomised All-comers Trials

Abstract

Introduction: The new generation thinner-strut silicon carbide (SiC) coated cobalt chromium (CoCr) bare-metal stents (BMS) are designed to accelerate rapid endothelialisation and reduce thrombogenicity when implanted in coronary arteries. However, smaller studies suggest reduced efficacy with higher rates of symptomatic restenosis in patients receiving the newer generation BMS. Objective: We investigated the efficacy and safety of a new generation thinner-strut SiC coated CoCr BMS (SCC-BMS) as compared to an older thin-strut uncoated CoCr BMS (UC-BMS) in patients presenting with coronary artery disease requiring stenting of large vessels (≥3.0mm) and thus at low risk of restenosis. Methods: We included all patients randomized to SCC- (n=761) or UC-BMS (n=765) in the BASKET-PROVE II and I trials, respectively. Design, patients, interventions and follow-up were similar between trials except differing regimens of dual antiplatelet therapy. The primary endpoint was clinically driven target-vessel revascularization within 24 months. Safety endpoints of cardiac death, non-fatal myocardial infarction (MI), and definite/probable stent thrombosis were also assessed. We used Cox proportional hazards regressions to estimate relative hazards adjusting for known confounders. Results: Demographics, clinical presentation, and risk factors were comparable between the groups, but patients receiving SCC-BMS underwent less complex procedures. Rates of the primary endpoint were 10.4% in the SCC-BMS group and 8.4% among patients receiving UC-BMS yielding an adjusted relative hazard (HR) of 1.46 ([1.03-2.07], p=0.032). Estimates for the safety endpoints were: cardiac death (1.8% vs. 2.4% ; HR 0.77 [0.36-1.59], p=0.46), non-fatal MI (3.2% vs. 2.5% ; HR 1.68 [0.88-3.21], p=0.11), and definite/probable stent thrombosis (0.8% vs. 1.0% ; HR 0.97 [0.32-3.00], p=0.96). We detected no particular subgroups driving the increased risk of target-vessel revascularization in the SCC-BMS group. Conclusions: In patients requiring stenting of large coronary arteries, use of the newer generation SCC-BMS was associated with a higher risk of symptomatic restenosis despite less complex procedures compared to the UC-BMS with no signs of an offsetting safety benefit.