Abstract:Objective To study the application of dual antiplatelet therapy (DAPT) in the patients with very late stent thrombosis (VLST) after implantation of drug-eluting stent (DES), and to determine the effect of different durations of DAPT on long-term prognosis of these patients. Methods All of the patients with angiographically defined VLST out of 3 945 patients undergoing emergent coronary angiography in our heart center from January 2006 to February 2013 were recruited in this study. The patients were divided into 2 groups according to whether receiving continuous DAPT after implantation. The clinical data, angiographic results and interventional data were compared between the 2 groups. Major adverse cardiac events (MACE) including nonfatal myocardial infarction (MI), recurrence of stent thrombosis (ST), target vessel revascularization (TVR), and death in all causes were compared to determine the different durations of DAPT on the prognosis. Predictors of MACE during long-term follow-up were confirmed in these patients. Results Sixty-two patients were enrolled, consisting of 55 males and 7 females, with age from 41 to 82 (58.6±10.2) years. The time from first implantation of DES to occurrence of VLST was from 12.5 to 84 (38.7±18.1) months. One patient died in hospital due to cerebral hemorrhage. The other 61 patients survived to discharge, and MACE occurred in 17 patients of them during follow-up of 5 to 88 (32.1±19.1) months. Kaplan-Meier survival analysis showed the estimated MACE-free survival was 45.1%. Compared with the patients without continuous DAPT (n=24, 13/24, 54.2%), the MACE rate was obviously lower in those with continuous DAPT (n=38, 5/38, 13.2%, P=0.001). Based on the occurrence of MACE, univariate Cox analysis revealed the independent predictors for MACE-free were re-implantation of the first-generation of DES [hazard ratio (HR): 2.69, P=0.04] and continuous DAPT (HR: 0.25, P=0.01) during our long-term follow-up. Multivariate COX analysis indicated that continuous DAPT was the only predictor for MACE-free (HR: 0.30, 95% CI: 0.09 to 0.97, P=0.04). Conclusion Long-term outcomes for DES patients having VLST are unfavorable, with high incidence of MACE. So, continuous DAPT should be prescribed to prevent long-term MACE.