Long-term outcomes following very late stent thrombosis of drug-eluting stent

Abstract

Background: Long-term outcomes of very late stent thrombosis (VLST) after implantation of drug-eluting stents (DES) are still unclear. The aim was to evaluate the long-term outcomes after VLST of DES, and to analyze the related factors of long-term outcomes in these patients.

Methods: From January 2006 to February 2013, patients with angiographically defined VLST were studied. The clinical characteristics, angiography and interventional data, and anti-platelet therapy protocols were analyzed. The patients were divided into two groups according to the occurrence of major adverse cardiac events (MACE) during follow-up. The clinical and interventional data between the two groups were compared.

Results: Sixty-two patients were enrolled consisting of 55 males and 7 females with an average age of 58.6±10.2 (41-82) years. The mean time from first implantation of DES to occurrence of VLST was 38.7±18.1 (12.5-84) months. One patient died in hospital. Sixty-one patients survived to discharge, and MACE occurred in 17 patients after a median follow-up of 32.1±19.1 (median: 44, range 5-88) months. The total MACE rate was 29.0% (18/62), and Kaplan-Meier survival analysis showed the estimated MACE-free survival was 45.1%. The rate of implantation of an additional first-generation DES during the first VLST in the group with events was higher (44.4% vs.11.4%, respectively, p=0.007). The percentage of continuous dual antiplatelet therapy (DAPT) at the longest available follow-up was higher in the event-free group (27.8% vs. 75.0%, respectively, p=0.001). Multivariable Cox regression analysis revealed that the only independent predictors for freedom of MACE during long-term follow-up was continuous DAPT at the longest available follow-up [hazard ratio (HR)=0.30, 95% CI: 0.09-0.97, p=0.04].

Conclusions: Long-term outcomes after VLST were unfavorable. Implantation of an additional first-generation DES might be avoided, and DAPT should be continued.

Keywords: Anti-platelet therapy; Drug-eluting stent; Follow-up; Very late stent thrombosis.