Department of Cardiovascular Medicine, Wakayama Medical University, Wakayama, Japan.
Circ J. 2011;75(1):106-12. doi: 10.1253/circj.cj-10-0574. Epub 2010 Oct 28.
Late stent thrombosis (LST) after drug-eluting stent (DES) implantation is a major clinical problem that has not been fully explained. Incomplete neointimal coverage of stent struts is an important morphometric predictor of LST, which may be associated with impaired healing and the absence of full coverage of struts at branch-point ostia. Optical coherence tomography (OCT) was performed to compare 3 types of stents placed across side branches.
At 9-month follow-up, the neointimal coverage of the struts of 58 stents across a side branch was measured by OCT (bare metal (BMS), n = 20; sirolimus-eluting (SES), n = 23; paclitaxel-eluting (PES), n = 15). According to the diameter ratio of side branch to main vessel, the side branches were classified as either large (ratio > 0.33) or small (ratio ≤ 0.33). BMS had the lowest frequency of uncovered struts (29.4%) and the greatest neointimal thickness on the struts (123 ± 33 µm). Neointimal thickness on the struts was less for SES than for PES (72 ± 16 vs. 91 ± 22 µm, P = 0.009), but there was no difference in the frequency of uncovered struts (66.1% vs. 58.6%, P=0.493). For large side branches, the frequency of uncovered struts was greater than in the small group for SES (87.5% vs. 40.7%, P = 0.0002) and PES (83.3% vs. 18.2%; P = 0.0013); there was no significant difference for BMS (43.8% vs. 16.7%, P = 0.138).
Neointimal coverage on struts across a side branch was less frequently observed in DES than in BMS, particularly in large side branches.
药物洗脱支架（DES）植入后晚期支架血栓（LST）是一个尚未完全阐明的重要临床问题。支架梁不完全覆盖是 LST 的重要形态学预测因子，可能与愈合不良以及支架梁在分支开口处不完全覆盖有关。光学相干断层扫描（OCT）用于比较穿过侧支的 3 种支架。
在 9 个月的随访中，通过 OCT 测量了 58 个穿过侧支的支架梁的新生内膜覆盖（裸金属（BMS），n = 20；西罗莫司洗脱（SES），n = 23；紫杉醇洗脱（PES），n = 15）。根据侧支与主血管直径比，将侧支分为大（比值>0.33）或小（比值≤0.33）。BMS 无覆盖支架的频率最低（29.4%），支架梁上的新生内膜最厚（123 ± 33 µm）。SES 的支架梁上的新生内膜厚度小于 PES（72 ± 16 对 91 ± 22 µm，P = 0.009），但无覆盖支架的频率无差异（66.1%对 58.6%，P=0.493）。对于大的侧支，SES 和 PES 的无覆盖支架梁的频率大于小的侧支（SES 为 87.5%对 40.7%，P = 0.0002；PES 为 83.3%对 18.2%；P = 0.0013）；BMS 无显著差异（43.8%对 16.7%，P = 0.138）。
DES 支架梁的新生内膜覆盖比 BMS 支架更不常见，特别是在大的侧支中。
