Time-Varying Outcomes With the Absorb Bioresorbable Vascular Scaffold During 5-Year Follow-up

Abstract

Bioresorbable scaffolds were designed to provide clinical benefits after their complete bioresorption. Prior studies demonstrated early risks with the Absorb polymeric bioresorbable vascular scaffold (BVS). Whether this risk profile changes over time during the course of its bioresorption is unknown. To examine outcomes of the first-generation BVS before and after 3 years, the point of its complete bioresorption in animals. We searched MEDLINE and the Cochrane database, conference proceedings, and public websites for relevant studies. Eligible studies were randomized clinical trials of BVS vs metallic drug-eluting stents in patients with coronary artery disease with at least 5-year follow-up. Four trials of BVS vs everolimus-eluting stents (EES) with 3384 patients met criteria. Individual patient data from the 4 trials were pooled, and summary-level meta-analysis was performed. The major effectiveness and safety measures were target lesion failure (TLF; cardiac death, target vessel-related myocardial infarction, or ischemia-driven target lesion revascularization) and device thrombosis. Outcomes were examined through 5-year follow-up and between 0 to 3 and 3 to 5 years. Mean age for the 3384 patients was 62.8 years; 2452 patients were men (72.5%), and diabetes was present in 1020 patients (30.2%). Through 5-year follow-up, treatment with BVS compared with EES was associated with higher rates of TLF (14.9% vs 11.6%; HR, 1.26; 95% CI, 1.03-1.54; P = .03) and device thrombosis (2.5% vs 0.8%; HR, 2.87; 95% CI, 1.46-5.65; P = .002). Target lesion failure occurred in 11.6% of BVS-treated patients vs 7.9% of EES-treated patients between 0 to 3 years (HR, 1.42; 95% CI, 1.12-1.80), and 4.3% of BVS-treated patients vs 4.5% of EES-treated patients between 3 to 5 years (HR, 0.92; 95% CI, 0.64-1.31) (P for interaction = .046). Device thrombosis occurred in 2.4% of BVS-treated patients vs 0.6% of EES-treated patients between 0 to 3 years (HR, 3.86; 95% CI, 1.75-8.50) and 0.1% of BVS-treated patients vs 0.3% of EES-treated patients between 3 to 5 years (HR, 0.44; 95% CI, 0.07-2.70) (P for interaction = .03). These results were consistent by spline analysis and after multiple imputation and multivariable analysis. The period of excess risk for the first-generation Absorb BVS ends at 3 years. These data provide mechanistic insights into the timing of adverse events after BVS and identify the hurdles to be overcome for bioresorbable technology to be accepted as a valid alternative for patients with coronary artery disease. ClinicalTrials.gov identifiers: NCT01751906, NCT01844284, NCT01923740, and NCT01425281.