Late Stent Recoil of the Bioabsorbable Everolimus-Eluting Coronary Stent and its Relationship With Plaque Morphology
Objectives: This study sought to evaluate late recoil of a novel bioabsorbable everolimus-eluting coronary stent (BVS), which is composed of a poly-L-lactic acid backbone, coated with a bioabsorbable polymer containing everolimus. Background: Little is known about the mechanical behavior of bioabsorbable polymer stents after deployment in diseased human coronary arteries. Methods: The study population consisted of 16 patients, who were treated with elective BVS implantation for single de novo native coronary artery lesions and were followed at 6 months. All patients underwent an intravascular ultrasound examination at post-procedure and follow-up. A total of 484 paired cross-sectional areas (CSAs) were acquired and analyzed. Late absolute stent recoil was defined as stent area at post-procedure (X) - stent area at follow-up (Y). Late percent stent recoil was defined as (X - Y)/X × 100. In each CSA, plaque morphology was assessed qualitatively and classified as calcific, fibronecrotic, or fibrocellular plaque. Results: Late absolute and percent recoil of the BVS was 0.65 ± 1.71 mm2(95% confidence interval [CI]: 0.49 to 0.80 mm2) and 7.60 ± 23.3% (95% CI: 5.52% to 9.68%). Calcified plaques resulted in significantly less late recoil (0.20 ± 1.54 mm2and 1.97 ± 22.2%) than fibronecrotic plaques (1.03 ± 2.12 mm2and 12.4 ± 28.0%, p = 0.001 and p = 0.001, respectively) or fibrocellular plaque (0.74 ± 1.48 mm2and 8.90 ± 19.8%, p = 0.001 and p = 0.001, respectively). Conclusions: The BVS shrank in size during the follow-up period. The lesion morphology of stented segments might affect the degree of late recoil of the BVS. (ABSORB Everolimus Eluting Coronary Stent System First in Man Clinical Investigation; NCT00300131).