Vascular response to bioresorbable polymer sirolimus-eluting stent vs. permanent polymer everolimus-eluting stent at 9-month follow-up: an optical coherence tomography sub-study from the CENTURY II trial

AIMS The Ultimaster bioresorbable polymer sirolimus-eluting stent (BP-SES) is a newly developed drug-eluting stent (DES) that consists of a thin-strut, cobalt chromium with bioresorbable polymer coated only albuminally. We sought to compare tissue coverage in coronary lesions treated with BP-SES with the XIENCE permanent polymer everolimus-eluting stent (PP-EES) using optical coherence tomography (OCT). METHODS AND RESULTS A total of 36 patients participated in the CENTURY II trial in our institution and were randomly assigned to BP-SES (n = 15) and PP-EES (n = 21). Of these, 27 patients (13 BP-SES and 14 PP-EES) underwent OCT at 9-month follow-up. Tissue coverage and apposition were assessed on each strut, and the results in both groups were compared using multilevel logistic or linear regression models with random effects at three levels: patient, lesion, and struts. A total of 6450 struts (BP-SES, n = 2951; PP-EES, n = 3499) were analysed. Thirty and 79 uncovered struts (1.02 and 2.26%, P = 0.35), and 3 and 4 malapposed struts (0.10 and 0.11%, P = 0.94) were found in BP-SES and PP-EES groups, respectively. Mean neointimal thickness did not significantly differ between both groups (110 ± 10 vs. 93 ± 10 µm, P = 0.22). No significant differences in per cent neointimal volume obstruction (13.2 ± 4.6 vs. 10.5 ± 4.9%, P = 0.14) or other areas-volumetric parameters were detected between both groups. CONCLUSION BP-SES shows an excellent vascular healing response at 9-month follow-up, which is similar to PP-EES.