Edge vascular response after resorption of the everolimus-eluting bioresorbable vascular scaffold: A 5-year serial optical coherence tomography study

Background: The edge vascular response (EVR) has been linked to important prognostic implications in patients treated with permanent metallic stents. We aimed to investigate the relationship of EVR with the geometric changes in the everolimus-eluting bioresorbable scaffold using serial optical coherence tomography (OCT) analysis. Methods and Results: In the first-in-man ABSORB trial, 28 patients (29 lesions) underwent serial OCT at 4 different time points (Cohort B1: post-procedure, 6, 24, and 60 months [n=13]; Cohort B2: post-procedure, 12, 36, and 60 months [n=15]) following implantation of the scaffold. In Cohort B1, there was no significant luminal change at the distal or proximal edge segment throughout the entire follow-up. In contrast, there was a significant reduction of the lumen flow area (LFA) of the scaffold between post-procedure and 6 months (−1.03±0.49 mm² [P<0.001]), whereas between 6 and 60 months the LFA remained stable (+0.31±1.00 mm² [P=0.293]). In Cohort B2, there was a significant luminal reduction of the proximal edge between post-procedure and 12 months (−0.57±0.74 mm² [P=0.017]), whereas the lumen area remained stable (−0.26±1.22 mm² [P=0.462]) between 12 and 60 months. The scaffold LFA showed a change similar to that observed in Cohort B1. Conclusions: Our study demonstrated a reduction in the scaffold luminal area in the absence of major EVR, suggesting that the physiological continuity of the lumen contour is restored long term.