Mechanisms of Very Late Bioresorbable Scaffold Thrombosis: The INVEST Registry

Very late scaffold thrombosis (VLScT) occurs more frequently after bioresorbable scaffold (Absorb BVS 1.1, Abbott Vascular, Santa Clara, California) implantation than with metallic everolimus-eluting stents. The purpose of this study was to elucidate mechanisms underlying VLScT as assessed by optical coherence tomography (OCT). The INVEST (Independent OCT Registry on Very Late Bioresorbable Scaffold Thrombosis) registry is an international consortium of investigators who used OCT to examine patients with VLScT. Between June 2013 and May 2017, 36 patients with 38 lesions who had VLScT underwent OCT at 19 centers. VLScT occurred at a median of 20 months (interquartile range: 16 to 27 months) after implantation. At the time of VLScT, 83% of patients received aspirin monotherapy and 17% received dual-antiplatelet therapy. The mechanisms underlying VLScT were (in descending order) scaffold discontinuity (42.1%), malapposition (18.4%), neoatherosclerosis (18.4%), underexpansion or scaffold recoil (10.5%), uncovered struts (5.3%), and edge-related disease progression (2.6%). Discontinuity (odds ratio [OR]: 110; 95% confidence interval [CI]: 73.5 to 173; p <0.001), malapposed struts (OR: 17.0; 95% CI: 14.8 to 19.7; p <0.001), and uncovered struts (OR: 7.3; 95% CI: 6.2 to 8.8; p