Relationship between the mean platelet aggregation degree and the prognosis of patients underwent long-term dual antiplatelet therapy following drug eluting stent implantation

Abstract

To evaluate the association between the mean platelet aggregation degree and the prognosis of patients underwent long-term dual antiplatelet therapy (DAPT more than 12 months) following drug eluting stent (DES) implantation. A total of 752 patients were retrospectively analyzed who were received DES between September 2006 and June 2009. Adenosine diphosphate-induced platelet aggregation (ADP) was monitored during the course of treatment with DAPT, and the mean platelet aggregation degree of each participant was calculated. Based on the mean platelet aggregation degree, patients were divided into the low ADP degree group (374 cases) and the high ADP degree group (378 cases). The median follow-up period was 32.2(25.1, 34.8) months. The comparison of the composite endpoints (all-cause death, nonfatal myocardial infarction, stent thrombosis, repeat revascularization and stroke) was performed between the two groups. Compared with the high ADP degree group, there were more male, younger and smoker patients in the low ADP degree group (all P<0.05). COX regression analysis showed that the low ADP degree group was associated with a decreased incidence of primary endpoints (HR=0.463, 95%CI 0.23-0.92, P=0.028). After adjustment with multivariable COX regression analysis, the relationship was proven to be independent of other risk factors (HR=0.495, 95%CI 0.25-0.99, P=0.046). The Kaplan-Meier curve demonstrated the incidence of the composite endpoints was significantly higher in high ADP degree group compared to that of low ADP degree group (log-rank χ(2)=5.042, P=0.025). The mean adenosine diphosphate-induced platelet aggregation degree is associated with the prognosis of patients underwent long term DAPT after DES implantation.