Sustained low clinical event rates in real-world patients receiving everolimus-eluting coronary stent system from a large, prospective, condition of approval study: 2-year clinical outcomes from the XIENCE V USA Study

Objectives: This 2-year follow-up of the XIENCE V USA study examines both the long-term safety and effectiveness of the everolimus-eluting coronary stent system (EECSS) in real-world patients.

Background: The safety and effectiveness of EECSS at 1 year in real-world clinical settings have been demonstrated in XIENCE V USA trial with low rates of target lesion revascularization (TLR), cardiac death, myocardial infarction (MI), and stent thrombosis (ST). Data on whether efficacy is maintained after 1 year and the event rate of very late stent thrombosis (VLST) between 1 and 2 years have not yet been reported.

Methods: XIENCE V USA is a prospective, multicenter, single-arm, FDA required condition of approval study designed to examine the safety and effectiveness of EECSS in an all-inclusive, consecutively enrolled population from real-world clinical settings. Clinical end-point events, including ST, cardiac death, MI, and revascularization were adjudicated by an independent Clinical Events Committee.

Results: Four thousand eight hundred and seventy-three (96.4%) out of 5,054 participants (1,875 standard-risk; 3,059 extended-risk) reached 2-year follow-up. The 2-year rate of Academic Research Consortium (ARC)-defined definite and probable ST was 0.96% (95% CI 0.70-1.28) in the overall population and 0.34% (95% CI 0.12-0.74) and 1.33% (95% CI 0.95-1.81) in the standard-risk and extended-risk cohorts, respectively. The rate of VLST was 0.06% in the overall population, 0.0% in the standard-risk, and 0.10% in the extended-risk cohorts. The 2-year composite rate of cardiac death and ARC-defined MI was 8.9% (95% CI 8.08-9.70) in the overall population and 5.6% (95% CI 4.61-6.78) and 10.8% (95% CI 9.71-11.94) in the standard-risk and extended-risk cohorts, respectively.

Conclusion: Low event rates observed at 1 year were maintained through 2 years. Despite the increased number of patients who discontinued dual antiplatelet therapy by 2 years, the ST rate remained consistently low, and <1% at 2 years due to low VLST occurrence. These results demonstrate continued safety and effectiveness of the XIENCE V everolimus-eluting stent in a highly complex, real-world patient population through 2 years.