Impact of Dual Antiplatelet Therapy Beyond 1 Year on Clinical Outcomes of Patients With Stent Fracture or Peri-Stent Contrast Staining After Sirolimus-Eluting Stent Implantation

Background: Stent fracture (SF) and peri-stent contrast staining (PSS) after sirolimus-eluting stent (SES) implantation are considered to be related to very late stent thrombosis (VLST). How dual antiplatelet therapy (DAPT) beyond 1 year affects the clinical outcomes of patients with SF or PSS remains unclear. Methods and Results: Based on their DAPT status, 1,962 patients undergoing SES implantation were classified as on-thienopyridine (n=1,404) or off-thienopyridine (n=558). The 6-year incidence of VLST was significantly lower in the on-thienopyridine patients (0.56% vs. 1.8%, P=0.01), whereas cardiac death and myocardial infarction (MI) were similar (5.0% vs. 6.2%, P=0.31; 3.2% vs. 4.0%, P=0.33; respectively). The 1,962 patients were also classified as having SF/PSS (n=256) or non-SF/PSS (n=1,706). In the SF/PSS group, VLST and MI were significantly lower in on-thienopyridine patients (1.9% vs. 10.1%, P=0.003; 3.5% vs. 10.3%, P=0.02; respectively). In the non-SF/PSS group, VLST and MI were similar (0.36% vs. 0.45%, P=0.78; 3.2% vs. 3.0%, P=0.93; respectively). In both groups, cardiac death was similar (3.6% vs. 4.3%, P=0.78; 5.2% vs. 6.5%, P=0.32; respectively). Conclusions: Prolonged DAPT was associated with significantly lower incidences of VLST and MI in the SF/PSS group, but had no effect on cardiac death, VLST, or MI in the non-SF/PSS group.