A Comparison of the Conformability of Everolimus-Eluting Bioresorbable Vascular Scaffolds to Metal Platform Coronary Stents

Objectives The aim of this study was to assess the differences in terms of curvature and angulation of the treated vessel after the deployment of either a metallic stent or a polymeric scaffold device. Background Conformability of metallic platform stents (MPS) is the major determinant of geometric changes in coronary arteries caused by the stent deployment. It is not known how bioresorbable polymeric devices perform in this setting. Methods This retrospective study compares 102 patients who received an MPS (Multi-link Vision or Xience V, Abbott Vascular, Santa Clara, California) in the SPIRIT FIRST and II trials with 89 patients treated with the Revision 1.1 everolimus-eluting bioresorbable vascular scaffold (BVS) (Abbott Vascular, Santa Clara, California) from cohort B of the ABSORB (A bioabsorbable everolimus-eluting coronary stent system) trial. All patients were treated with a single 3 × 18 mm device. Curvature and angulation were measured with dedicated software by angiography. Results Both the MPS and BVS groups had significant changes in relative region curvature (MPS vs. BVS: 28.7% vs. 7.5%) and angulation (MPS vs. BVS: 25.4% vs. 13.4%) after deployment. The unadjusted comparisons between the 2 groups showed for BVS a nonsignificant trend for less change in region curvature after deployment (MPS vs. BVS: 0.085 cm−1 vs. 0.056 cm−1, p = 0.06) and a significantly lower modification of angulation (MPS vs. BVS 6.4° vs. 4.3°, p = 0.03). By multivariate regression analysis, the independent predictors of changes in curvature and angulation were the pre-treatment region curvature, the pre-treatment region angulation, and the used device. Conclusions Bioresorbable vascular scaffolds have better conformability than conventional MPS. The clinical significance of the observed differences will require further investigation.