Proximal and distal maximal luminal diameters as a guide to appropriate deployment of the ABSORB everolimus‐eluting bioresorbable vascular scaffold

Objectives : Due to the limited distensibility of the everolimus‐eluting bioresorbable vascular scaffold (ABSORB) compared to metallic platform stents, quantitative coronary arteriography (QCA) is a mandatory requirement for ABSORB deployment in the on‐going ABSORB EXTEND Single‐Arm Study. Visual assessment of vessel size in the ABSORB Cohort B study often lead to under and over‐sizing of the 3 mm ABSORB in coronary vessels (recommended range of the vessel diameter ≥2.5 mm and ≤3.3 mm), with an increased risk of spontaneous incomplete scaffold apposition post ABSORB deployment. We report whether mandatory QCA assessment of vessel size pre‐implantation, utilizing the maximal luminal diameter (Dmax) and established interpolated reference vessel diameter (RVD) measurements, has improved device/vessel sizing. Methods : Pre‐implantation post‐hoc QCA analyses of all 101 patients from ABSORB Cohort B (102 lesions) and first consecutive 101 patients (108 lesions) from ABSORB EXTEND were undertaken by an independent core‐laboratory; all patients had a 3 mm ABSORB implanted. Comparative analyses were performed. Results : Within ABSORB Cohort B, a greater number of over‐sized vessels (>3.3 mm) were identified utilizing the Dmax compared to the interpolated RVD (17 vessels, 16.7% vs. 3 vessels, 2.9%; P = 0.002). Comparative analyses demonstrated a greater number of appropriate vessel‐size selection (75 vessels, 69.4% vs. 48 vessels, 47.1%; P = 0.001), a trend towards a reduction in implantation in small (<2.5 mm) vessels (29 vessels, 26.9% vs. 40 vessels, 39.2%; P = 0.057) and a significant decrease in the implantation in large (>3.3 mm) vessels (4 vessels, 3.7% vs. 17 vessels, 16.7%; P = 0.002) in ABSORB EXTEND. Bland–Altman plots suggested a good agreement between operator and core‐laboratory calculated Dmax measurements. Conclusions : The introduction of mandatory Dmax measurements of vessel size prior to ABSORB implantation significantly reduced the under‐sizing of the 3.0 mm scaffold in large vessels validating the use of this technique in vessel sizing prior to ABSORB implantation. © 2011 Wiley Periodicals, Inc.