Comparison of In Vivo Acute Stent Recoil Between the Bioresorbable Everolimus-Eluting Coronary Scaffolds (Revision 1.0 and 1.1) and the Metallic Everolimus-Eluting Stent

Objectives: The ABSORB cohort A trial using the bioresorbable everolimus-eluting scaffold (BVS revision 1.0, Abbott Vascular) demonstrated a slightly higher acute recoil with BVS than with metallic stents. To reinforce the mechanical strength of the scaffold, the new BVS scaffold (revision 1.1) with modified strut design was developed and tested in the ABSORB cohort B trial. This study sought to evaluate and compare the in vivo acute scaffold recoil of the BVS revision 1.0 in ABSORB cohort A and the BVS revision 1.1 in ABSORB cohort B with the historical recoil of the XIENCE V (R) everolimuseluting metal stent (EES, SPIRIT I and II). Methods: In the ABSORB cohort B trial, 101 patients with one or two de-novo lesions were enrolled at 10 sites. In ABSORB cohort A, 27 patients treated with a BVS 1.0 were analyzed and compared with EES. Acute absolute recoil, assessed by quantitative coronary angiography, was defined as the difference between mean diameter of the last inflated balloon at the highest pressure (X) and mean lumen diameter of the stent immediately after the last balloon deflation (Y). Acute percent recoil was defined as (X - Y)/X and expressed as a percentage. Results: Out of 101 patients enrolled in the ABSORB cohort B trial, 88 patients are available for complete analysis of acute recoil. Absolute recoil of BVS 1.1 (0.19 +/- 0.18 mm) was numerically higher than metallic EES (vs. 0.13 +/- 0.21 mm) and similar to BVS 1.0 (0.20 +/- 0.21 mm) but the differences did not reach statistical significance (P = 0.40). The acute percent recoil demonstrated the same trend (EES: 4.3% +/- 7.1%, BVS 1.0: 6.9% +/- 7.0%, BVS 1.1: 6.7% +/- 6.4%, P = 0.22). In the multivariate regression model, high balloon/artery ratio (>1.1) (OR 1.91 [1.34-2.71]) was the predictive for high absolute recoil (>0.27 mm) while (larger) preprocedural MLD was protective (OR 0.84 [0.72-0.99]). The stent/scaffold type was not a predictor of acute recoil. Conclusions: The average in vivo acute scaffold recoil of the BVS 1.1 is slightly higher than the metallic EES. However, the scaffold/stent type was not predictive of high acute recoil, while implantation in undersized vessels or usage of oversized devices might confound the results. (C) 2011 Wiley-Liss, Inc.