Angiographic and Optical Coherence Tomography Insights Into Bioresorbable Scaffold Thrombosis

M etallic drug-eluting stents (DESs) are the current standard for invasive treatment of coronary artery disease. However, metallic DES have been associated with late complications such as neoatherosclerosis and incomplete healing that can lead to failure even at long-term follow-up. Bioresorbable vascular scaffolds (BVSs) are a new treatment for coronary artery disease that could potentially alleviate such problems. To date, bioresorbable scaffolds have been evaluated in first-in-man or highly selected study cohorts with simple lesions in low-risk patient populations, 4–7 whereas vas-cular response in lesions of real-world patients might differ. As BVSs are being increasingly used in more complex lesions, several cases of BVS thrombosis have been reported. 8–10 In metallic DES, intravascular imaging has elucidated patho-physiologic mechanisms of stent thrombosis, underscoring the significance of procedural factors such as inadequate stent expansion and vascular trauma for acute thrombosis 11,12 or delayed healing and neoatherosclerosis for late thrombosis. 1,2 Whether BVS thrombosis is amenable to the same factors remains unknown. We aimed to present angiographic and optical coherence tomography (OCT) findings in a series of patients with definite bioresorbable scaffold thrombosis treated in our catheter-ization laboratory and compare them with a control group of patients with definite metallic stent thrombosis. The everolimus-eluting BVS (Absorb; Abbott Vascular, Santa Clara, CA) has been used in clinical trials in our center since 2006. 4–7 Since Background—As bioresorbable vascular scaffolds (BVSs) are being increasingly used in complex real-world lesions and populations, BVS thrombosis cases have been reported. We present angiographic and optical coherence tomography (OCT) findings in a series of patients treated in our center for definite bioresorbable scaffold thrombosis. Methods and Results—Up to June 2014, 14 patients presented with definite BVS thrombosis in our center. OCT was performed in 9 patients at the operator's discretion. Angiographic and OCT findings were compared with a control group comprising 15 patients with definite metallic stent thrombosis. In the BVS group, time interval from index procedure to scaffold thrombosis ranged from 0 to 675 days. Incomplete lesion coverage by angiography was identified in 4 of 14 cases, malapposition by OCT in 5 of 9 cases, strut discontinuity in 2 of 9 cases, and underexpansion in 2 of 9 cases. Five patients had discontinued dual antiplatelet therapy, and in 3 of them discontinued dual antiplatelet therapy discontinuation had occurred the week preceding the event. There were no significant differences in angiographic or OCT findings between BVS and metallic stent …