Comparison of in Vivo Acute Stent Recoil Between the Bioabsorbable Everolimus-eluting Coronary Stent and the Everolimus-eluting Cobalt Chromium Coronary Stent: Insights from the ABSORB and SPIRIT Trials

Objectives: This study sought to evaluate and compare in vivo acute stent recoil of a novel bioabsorbable stent and a metallic stent.

Background: The bioabsorbable everolimus-eluting coronary stent (BVS) is composed of a poly-L-lactic acid backbone, coated with a bioabsorbable polymer containing the antiproliferative drug, everolimus, and expected to be totally metabolized and absorbed in the human body. Because the BVS is made from polymer, it may have more acute recoil than metallic stents in vivo.

Methods: A total of 54 patients, who underwent elective stent implantation for single de novo native coronary artery lesions, were enrolled: 27 patients treated with the BVS and 27 patients treated with the everolimus-eluting cobalt chromium stent (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: Acute absolute recoil of the BVS and EES was 0.20 +/- 0.21 mm and 0.13 +/- 0.21 mm, respectively (P = 0.32). Acute percent recoil was 6.9% +/- 7.0% in the BVS group and 4.3% +/- 7.1% in the EES group (P = 0.25).

Conclusions: In vivo acute stent recoil of the BVS is slightly larger but insignificantly different from that of the EES, implying that the BVS may have good radial strength similar to the metallic stent.