Evaluation of a fully bioresorbable vascular scaffold in patients with coronary artery disease: design of and rationale for the ABSORB III randomized trial.

Background: Randomized trials have demonstrated progressive improvements in clinical and angiographic measures of restenosis with technologic iterations from balloon angioplasty to bare-metal stents and subsequently to drug-eluting stents (DES). However, the permanent presence of a metal stent prevents coronary vasomotion, autoregulation, and adaptive coronary remodeling. The limitations imposed by a permanent metal implant may be overcome with a bioresorbable scaffold. ABSORB III is a large-scale, multicenter, randomized trial designed to support US premarket approval of the ABSORB BVS platform and is the first study with sufficient size to allow valid examination of the relative clinical outcomes between metallic DES and bioresorbable scaffold.

Design: ABSORB III (ClincalTrials.gov NCT01751906) will register approximately 2,262 patients and includes a lead-in phase (n = 50), the primary randomized analysis group (n = 2,000), an imaging cohort (n = 200), and a pharmacokinetic substudy (n = 12). In the primary analysis group, approximately 2,000 patients with up to 2 de novo native coronary artery lesions in separate epicardial vessels will be prospectively assigned in a 2:1 ratio to ABSORB BVS versus XIENCE everolimus-eluting stents (EES). The primary end point is target lesion failure (the composite of cardiac death, target vessel-related myocardial infarction, or ischemia-driven target lesion revascularization) at 1 year, powered for noninferiority of ABSORB BVS compared to XIENCE EES. Clinical follow-up will continue for 5 years. Enrollment has been completed, and the principal results will be available in the fall of 2015.

Conclusions: The large-scale ABSORB III randomized trial will evaluate the safety and effectiveness of ABSORB BVS compared to XIENCE EES in the treatment of patients with coronary artery disease.