Risk of in-stent thrombus formation at one year after drug-eluting stent implantation

IntroductionAlthough very late stent thrombosis is an important problem with drug-eluting stents, risks for in-stent thrombus formation have not been clarified. Therefore, we examined the risks among patient and lesion characteristics by direct visualization of the stented lesion by angioscopy.Materials and methodsConsecutive patients (n = 118) who received successful angioscopic examination of drug-eluting (sirolimus- or paclitaxel-eluting) stents at 1-year after implantation were included. Presence or absence of thrombus directly on the area of each condition determined by the combination of lesion color (white or yellow) and neointima coverage (grade 0 − 2) was evaluated for each stent; and the factors associated with the presence of thrombus were analyzed.ResultsMultivariate logistic regression analysis revealed lesion color (= yellow; odds ratio [OR] 5.5, 95% confidence interval [CI] 3.0-10, p < 0.001), neointima coverage (= grade 0 or 1; OR 5.5, 95% CI 2.4-13, p < 0.001), and stent type (= paclitaxel-eluting stent; OR 7.6, 95% CI 3.9-15, p < 0.001) as independent contributors for in-stent thrombus formation.ConclusionYellow color of the lesion, poor neointima coverage, and use of paclitaxel-eluting stent were the risks of in-stent thrombus formation at 1 year after DES implantation.