Outcomes With Absorb Bioresorbable Scaffold for CAD Treatment
What is the safety and efficacy of Bioresorbable vascular scaffolds (BVS) as compared to drug-eluting stents within 2 years after implantation and between 1 and 2 years?
The investigators did a systematic review and meta-analysis of randomized trials in which patients were randomly assigned to everolimus-eluting Absorb BVS or metallic everolimus-eluting stents (EES) and followed up for at least 2 years. They searched MEDLINE, the Cochrane database, TCTMD, ClinicalTrials.gov, Clinical Trial Results, Cardiosource, and abstracts and presentations from major cardiovascular meetings up to April 1, 2017, to identify relevant studies. The primary efficacy outcome measure was the device-oriented composite endpoint (cardiac mortality, target vessel–related myocardial infarction (MI), or ischemia-driven target lesion revascularization) and the primary safety outcome measure was definite or probable device thrombosis. Individual patient data from the four ABSORB trials were used for landmark and subgroup analysis and multivariable modeling.
The study identified seven randomized trials in which 5,583 patients were randomly assigned to Absorb BVS (n = 3,261) or metallic EES (n = 2,322) and followed up for 2 years. BVS had higher 2-year relative risks of the device-oriented composite endpoint than did EES (9.4% [304 of 3,217] vs. 7.4% [169 of 2,299]; relative risk [RR], 1.29; 95% confidence interval [CI], 1.08–1.56; p = 0.0059). These differences were driven by increased rates of target vessel-related MI (5.8% [187 of 3,218] vs. 3.2% [74 of 2,299]; RR, 1.68 [95% CI, 1.29–2,19]; p = 0.0003) and ischemia-driven target lesion revascularization (5.3% [169 of 3,217] vs. 3.9% [90 of 2,300]; 1.40 [1.09–1.80]; p = 0.0090) with BVS, with nonsignificant differences in cardiac mortality. The cumulative 2-year incidence of device thrombosis was higher with BVS than with EES (2.3% [73 of 3,187] vs. 0.7% [16 of 2,281]; RR, 3.35; 95% CI, 1.96–5.72; p < 0.0001). Landmark analysis between 1 and 2 years also showed higher rates of the device-oriented composite endpoint (3.3% [69 of 2,100] vs. 1.9% [23 of 1,193]; RR, 1.64; 95% CI, 1.03–2.61; p = 0.0376) and device thrombosis (0.5% [11 of 2,085] vs. none [0 of 1,183]; p < 0.0001) in BVS-treated patients than in EES-treated patients.
The authors concluded that BVS was associated with increased rates of composite device-oriented adverse events and device thrombosis cumulatively at 2 years and between 1 and 2 years of follow-up compared with EES.
This study reports that BVS use was associated with increased 2-year rates of the device-oriented composite endpoint, patient-oriented composite endpoint, target vessel-related MI, all MI, and ischemia-driven target lesion revascularization, with no significant differences between devices in the 2-year cumulative relative risks of all-cause or cardiac mortality, all revascularization, or ischemia-driven revascularization. The primary safety endpoint of device thrombosis at 2 years occurred more commonly with BVS than with EES, contributing to increased rates of the device-oriented composite endpoint with BVS. While long-term follow-up is necessary to assess whether BVS risks continue to increase beyond 2 years, or whether BVS benefits emerge after complete device bioresorption and restoration of vascular homeostasis, there is little justification for the use of BVS at this time until safety issues are resolved.
Keywords: Absorbable Implants, Coronary Artery Disease, Drug-Eluting Stents, Hemostasis, Myocardial Infarction, Myocardial Ischemia, Myocardial Revascularization, Outcome Assessment (Health Care), Risk, Thrombosis
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