First Department of Medicine, Nara Medical University, Kashihara, Japan.
Circ J. 2009 Dec;73(12):2300-7. doi: 10.1253/circj.cj-08-1116. Epub 2009 Sep 29.
Late stent thrombosis related to delayed neointimal growth is a major concern after drug-eluting stent (DES) implantation. The time course of neointimal growth and risk factors of uncovered stent struts after sirolimus-eluting stent (SES) was studied using optical coherence tomography (OCT).
The 60 patients were enrolled and classified into G1 (follow-up period <9 months, n=27), G2 (9-24 months, n=18), and G3 (>25 months, n=15). The time elapsed since SES implantation was associated with a significant increase in mean neointimal area and neointimal thickness, and also with a significant decrease in the number of uncovered stent struts (G1: 14.8%, G2: 11.7%, and G3: 4.1%, P<0.001). However, only 17.6% of implanted SES was completely covered by neointima, even in the G3 period. Small-diameter SES, complex coronary lesions with lipid and calcium content adjacent to stent struts, and diabetes predicted delayed neointimal coverage of SES struts in G1.
Neointima inside SES progressively increases after the routine follow-up period, but only a few SES were completely covered at 3 years after implantation. OCT is a useful modality for assessing neointimal formation after SES implantation, and may give important information about the strategy of antiplatelet therapy after DES implantation.
药物洗脱支架（DES）植入后，与延迟性新生内膜生长相关的晚期支架内血栓形成是一个主要关注点。本研究采用光学相干断层成像术（OCT）研究了西罗莫司洗脱支架（SES）后新生内膜的时间进程及未覆盖支架梁的危险因素。
共纳入 60 例患者，分为 G1 组（随访时间<9 个月，n=27）、G2 组（9-24 个月，n=18）和 G3 组（>25 个月，n=15）。SES 植入后时间与平均新生内膜面积和新生内膜厚度的显著增加相关，也与未覆盖支架梁数量的显著减少相关（G1：14.8%，G2：11.7%，G3：4.1%，P<0.001）。然而，即使在 G3 期，也仅有 17.6%的植入 SES 完全被新生内膜覆盖。小直径 SES、支架梁附近有脂质和钙含量的复杂冠状动脉病变以及糖尿病预测了 G1 期 SES 支架梁的新生内膜覆盖延迟。
SES 内的新生内膜在常规随访期后逐渐增加，但在植入后 3 年仅有少数 SES 完全被覆盖。OCT 是评估 SES 植入后新生内膜形成的一种有用方式，可能为 DES 植入后的抗血小板治疗策略提供重要信息。
