Abstract 16718: The Impact of Discontinuation of Dual Antiplatelet Therapy and Stent Fracture or Peri-Stent Contrast Staining on Very Late Stent Thrombosis After Sirolimus-Eluting Stent Implantation

Abstract

Objectives: We evaluated the impact of discontinuation of dual antiplatelet therapy (DAPT) and stent fracture (SF) or peri-stent contrast staining (PSS) on very late stent thrombosis (VLST) after sirolimus-eluting stent (SES) implantation. Methods: Consecutive patients who had received the first SES implantation and had been evaluated by follow-up angiography within 12 months were analyzed. Stent thrombosis was defined according to the Academic Research Consortium definition. The incidence of VLST beyond 1 year after SES implantation was compared between the 4 groups of patients either with or without a diagnosis of SF or PSS at follow-up angiographic study within 12 months and continuation or discontinuation of DAPT. Results: Of 2494 patients who received the first SES implantation between November 2002 and December 2007, 2048 patients met the criteria for inclusion. The median duration of follow-up after the SES implantation was 1680 days (interquartile range 1362-1963 days). SF was observed at follow-up angiography within 12 months in 243 patients (11.9%), PSS in 59 patients (2.9%) and either SF or PSS (SF/PSS) in 271 patients (13.2%). Figure shows that the 5-year cumulative incidence of definite ST in patients stopped DAPT was significantly higher than that in patients continuing DAPT in the SF/PSS (+) group (11.4% vs. 0 %, p<0.001), whereas no differences were observed in patients stopped DAPT versus patients continuing DAPT in the SF/PSS (-) group (0.7% vs. 0.3%, p=0.29). The incidence of definite ST in patients stopped DAPT was also significantly higher than that in patients continuing DAPT in the SF (+) group and PSS (+) group, respectively (9.9% vs. 0%, p=0.001; 19.1% vs. 0%, p=0.041). Conclusions: DAPT should be continued when SF or PSS was observed at follow-up angiography after SES implantation. In contrast, it may be possible that DAPT will be discontinued when SF or PSS was not observed.