Incidence and Morphological Predictors of Intrastent Coronary Thrombus After Drug-Eluting Stent Implantation (from a Multicenter Registry)

The mechanisms responsible for late and very late stent thrombosis remain incompletely understood. This study aimed to evaluate the incidence and morphologic predictors of intrastent thrombus in patients after drug-eluting stent (DES) implantation using optical coherence tomography (OCT). A total of 208 patients with 262 DES who underwent follow-up OCT examination >6 months after DES implantation were included. The detailed vascular morphology including characteristics of neointima was analyzed. Thrombus was identified in 24 patients (11.5%) 11 months after DES implantation. Minimal lumen cross-sectional area was significantly smaller in the thrombus group than in the nonthrombus group (2.9 ± 1.7 vs 4.6 ± 2.0 mm²; p <0.001). No difference was found in the frequency of uncovered or malapposed struts between the 2 groups. Thin-cap fibroatheroma (20.6% vs 0.1%; p <0.001) and heterogeneous neointima (22.2% vs 9.0%; p = 0.001) were more frequently detected in the thrombus group compared to the nonthrombus group. Second-generation DES showed lower incidence of thrombus, uncovered struts, and extrastent lumen compared with first-generation DES. In conclusion, the present OCT study revealed that smaller lumen cross-sectional area and neointimal morphology are important factors associated with intrastent thrombus. Second-generation DES demonstrated improved arterial healing and a lower incidence of intrastent thrombus compared with first-generation DES.