A New Era of Prospective Real-World Safety Evaluation: Primary Report of XIENCE V USA (XIENCE V Everolimus Eluting Coronary Stent System Condition-of-Approval Post-Market Study)

Abstract

The XIENCE V USA (XIENCE V Everolimus Eluting Coronary Stent System Condition-of-Approval Post-Market study) sought to: 1) evaluate the safety of everolimus-eluting coronary stent systems (EECSS) in a contemporary cohort of real-world subjects; and 2) prospectively test the quality of event reporting with analysis of matched patients from the randomized SPIRIT IV (Clinical Evaluation of the XIENCE V Everolimus Eluting Coronary Stent System in the Treatment of Subjects With de Novo Native Coronary Artery Lesions) trial. Randomized trials have demonstrated the safety and efficacy of EECSS in selected "standard-risk" patients. The XIENCE V USA trial was a prospective, multicenter, single-arm study in unselected patients. The primary endpoint was Academic Research Consortium (ARC)-defined definite and probable stent thrombosis (ST); the co-primary endpoint was the composite of cardiac death and myocardial infarction at 1 year. Secondary analyses included: 1) stratification by standard-risk and extended-risk cohorts; and 2) late ST after dual antiplatelet therapy interruption. Of 5,054 participants (1,875 standard-risk; 3,179 extended-risk), 4,958 (98.1%) reached 1-year follow-up. The rate of ARC-defined definite and probable ST was 0.84% (95% confidence interval [CI]: 0.60% to 1.14%) in the overall population and 0.33% (95% CI: 0.12% to 10.72%) and 1.14% (95% CI: 0.80% to 11.58%) in the standard-risk and extended-risk cohorts, respectively. No late ST was observed after dual antiplatelet therapy interruption in either cohort after 6 months. The composite rate of cardiac death and ARC-defined myocardial infarction was 6.5% (95% CI: 5.79% to 17.17%) in the overall population, 3.8% (95% CI: 2.98% to 14.78%) in the standard-risk cohort, and 8.0% (95% CI: 7.09% to 19.02%) in the extended-risk cohort. This study comprehensively reports ST rates for EECSS in a contemporary real-world population. The absence of ST after dual antiplatelet therapy interruption beyond 6 months in standard-risk and high-risk patients is notable. Consistent safety outcomes between matched standard-risk cohorts from the XIENCE V USA study and the SPIRIT IV randomized trial suggest that this study affords a reliable benchmark for understanding the safety of EECSS in the context of real-world clinical practice. (XIENCE V Everolimus Eluting Coronary Stent System [EECSS] USA Post-Approval Study; NCT00676520).