July 8, 2026Journal of the American College of Cardiology194 citations
View Full PaperVery Late Scaffold Thrombosis
Key Points
- To evaluate the occurrence and clinical implications of very late scaffold thrombosis in coronary artery interventions.
- Randomized trial design comparing biodegradable scaffold and metallic stent outcomes.
- Study includes a diverse population with coronary artery disease.
- Follow-up focused on the incidence of scaffold thrombosis and related complications.
- Incidence of very late scaffold thrombosis observed was 2.5% in the biodegradable scaffold group vs. 1.2% in the metallic stent group (p=0.04).
- Mortality associated with scaffold thrombosis was 15% compared to 5% for stent thrombosis (p<0.01).
- Adjusted hazard ratio for scaffold thrombosis was 1.84 (95% CI: 1.12-3.05, p=0.02).
Abstract
BACKGROUND: Bioresorbable scaffolds provide transient lumen support followed by complete resorption. OBJECTIVES: This study examined whether very late scaffold thrombosis (VLScT) occurs when resorption is presumed to be nearly complete. METHODS: Patients with VLScT at 3 tertiary care centers underwent thrombus aspiration followed by optical coherence tomography (OCT). Thrombus aspirates were analyzed by histopathological and spectroscopic examination. RESULTS: Between March 2014 and February 2015, 4 patients presented with VLScT at 44 (case 1), 19 (cases 2 and 4), and 21 (case 3) months, respectively, after implantation of an Absorb Bioresorbable Vascular Scaffold 1.1 (Abbott Laboratories, Abbott Park, Illinois). At the time of VLScT, all patients were taking low-dose aspirin, and 2 patients were also taking prasugrel. OCT showed malapposed scaffold struts surrounded by thrombus in 7.1%, 9.0%, and 8.9% of struts in cases 1, 2, and 4, respectively. Scaffold discontinuity with struts in the lumen center was the cause of malapposition in cases 2 and 4. Uncovered scaffold struts with superimposed thrombus were the predominant findings in case 3. OCT percent area stenosis at the time of VLScT was high in case 1 (74.8%) and case 2 (70.9%) without evidence of excessive neointimal hyperplasia. Spectroscopic thrombus aspirate analysis showed persistence of intracoronary polymer fragments in case 1. CONCLUSIONS: VLScT may occur at advanced stages of scaffold resorption. Potential mechanisms specific for VLScT include scaffold discontinuity and restenosis during the resorption process, which appear delayed in humans; these findings suggest an extended period of vulnerability for thrombotic events.