Prospective observational angiographic and OCT follow-up at 6 months post-implantation of a biolimus-A9 eluting stent (BES) vs. a paclitaxel eluting stent (PES), with biodegradable polymer carriers. The primary outcome was the percent difference of uncovered struts between BESs and PESs.
A maximum likelihood model was used for analysis, to account for data clustering. Sixteen patients were treated with BES (28 lesions/4530 struts) and 16 with PES (23 lesions/4450 struts). Overall, BESs compared to PESs had more uncovered [0.41%vs. 0.21%, difference estimate (DE) 0.2 (95%CI, 0.06-0.34), p = 0.006], malapposed [0.18%vs. 0.04%, DE 0.14 (95%CI 0.05-0.23), p = 0.003], uncovered and malapposed [0.08%vs. 0.026%, DE 0.057 (95%CI 0.015-0.1), p = 0.01] and protruding struts [0.23%vs. 0.04%, DE 0.185 (95%CI 0.1-0.27), p < 0.001], and significantly lower neointimal thickness (59.3 卤 28.2 渭m vs. 201.7 卤 97.5, p < 0.001). None of the BESs was totally covered with neointima, in contrast to 5 (21.7%) PESs (p = 0.01). Thrombus was detected in 1 (3.6%) BES and 5 (21.7%) PESs (p = 0.05); however, no patient experienced clinical stent thrombosis.
Between two stents with biodegradable polymer, OCT demonstrated that BESs had more uncovered and malapposed struts compared to PESs at 6 months. This difference might be partly attributed to the more potent antiproliferative properties of biolimus-A9; however, its impact on clinical outcome and on the risk of LST is yet to be determined.