Intracoronary thrombus formation after drug-eluting stents implantation: Optical coherence tomographic study

Background: Intracoronary thrombus formation after drug-eluting stent (DES) implantation is not sufficiently evaluated. Methods: Optical coherence tomography (OCT) was performed in 226 patients (total DES n = 244, sirolimus-eluting stent [SES] n = 95, paclitaxel-eluting stent [PES] n = 62, zotarolimus-eluting stent [ZES] n = 87) after implantation (mean 11 months, range 3-66 months). Using OCT, we investigated the incidence and determinants of intracoronary thrombus. Results: Intracoronary thrombus was detected in 35 (14%) cases (27 SES [28%], 7 PES [11%], and 1 ZES [1%], P < .001) and was associated with longer stent, smaller stent diameter, and stents at bifurcation lesions. More uncovered stent struts (26 ± 23 vs 8 ± 17, P < .001) and malapposed stent struts (6 ± 14 vs 2 ± 6, P < .001) were also associated with intracoronary thrombus. Multiple logistic regression analysis found the following determinants of intracoronary thrombus: stent length ≥28 mm (odds ratio [OR] 7.31, 95% CI 1.79-29.86, P = .01), stent diameter <3.0 mm (OR 4.38, 95% CI 1.38-13.97, P = .01), and ≥8 uncovered struts in each stent (OR 3.29, 95% CI 1.07-10.17, P = .04). Conclusions: Length, size, and types of DES may be more important than clinical factors in intracoronary thrombus formation after DES implantations.