Association of subclinical intrastent thrombus detected 9 months after implantation of 2nd-generation drug-eluting stent with future major adverse cardiac events ― A coronary angioscopic study

Abstract

Background: Detection of yellow plaques (YP) by coronary angioscopy (CAS) 1 year after 1st-generation drug-eluting stent (DES) implantation has been related to future coronary events. However, the association between CAS findings and clinical outcomes following 2nd-generation DES implantation has not been investigated. Methods and Results: This study included a total of 248 2nd-generation DES in 179 patients, who were examined by CAS 9±2 months after implantation. Angioscopic evaluation included dominant neointimal coverage (NIC) grade, heterogeneity of NIC, presences of YP and intrastent thrombus. The outcome measure was major adverse cardiac events (MACE) defined as a composite of cardiac death, acute myocardial infarction and any coronary revascularization. The association between the CAS findings and MACE was evaluated using the Kaplan-Meier method. A Cox proportional hazards model was used to assess the predictors of MACE. The mean follow-up duration was 1,367±843 days. Dominant NIC grade (P=0.98), heterogeneity of NIC (P=0.20) and YP (P=0.53) were not associated with the incidence of MACE. However, intrastent thrombus was significantly associated with MACE (P=0.033). Intrastent thrombus (adjusted hazard ratio: 2.22; 95% confidence interval [CI]: 1.12–4.39), acute coronary syndrome (2.83; 95% CI: 1.42–5.67) and B2/C lesion (2.13; CI: 1.12–4.05) were independent predictors of MACE. Conclusions: Subclinical intrastent thrombus observed by CAS at 9 months after 2nd-generation DES implantation was independently associated with poor clinical outcome.