Background: Tissue coverage and strut apposition of drug eluting stents (DES), which can be assessed with 21
optical coherence tomography (OCT), may be associated with late stent thrombosis (LST). 22
Methods: Prospective observational angiographic and OCT follow-up at 6 months post-implantation of a 23
biolimus-A9 eluting stent (BES) vs. a paclitaxel eluting stent (PES), with biodegradable polymer carriers. The 24
primary outcome was the percent difference of uncovered struts between BESs and PESs. 25
Results: A maximum likelihood model was used for analysis, to account for data clustering. Sixteen patients 26
were treated with BES (28 lesions/4530 struts) and 16 with PES (23 lesions/4450 struts). Overall, BESs 27
compared to PESs had more uncovered [0.41% vs. 0.21%, difference estimate (DE) 0.2 (95% CI, 0.06–0.34), 28
p=0.006], malapposed [0.18% vs. 0.04%, DE 0.14 (95% CI 0.05–0.23), p=0.003], uncovered and malapposed 29
[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% 30
CI 0.1–0.27), pb0.001], and significantly lower neointimal thickness (59.3± 28.2 μm vs. 201.7± 97.5, 31
pb0.001). None of the BESs was totally covered with neointima, in contrast to 5 (21.7%) PESs (p=0.01). 32
Thrombus was detected in 1 (3.6%) BES and 5 (21.7%) PESs (p=0.05); however, no patient experienced 33
clinical stent thrombosis. 34
Conclusion: Between two stents with biodegradable polymer, OCT demonstrated that BESs had more 35
uncovered and malapposed struts compared to PESs at 6 months. This difference might be partly attributed to 36
the more potent antiproliferative properties of biolimus-A9; however, its impact on clinical outcome and on 37
the risk of LST is yet to be determined.
(EL)
University of Patras
