Premature Discontinuation of Dual Antiplatelet Therapy After Coronary Stenting in Veterans: Characteristics and Long-Term Outcomes.

Background Premature discontinuation of dual antiplatelet therapy (DAPT) after percutaneous coronary intervention is related to higher short-term risks of adverse outcomes. Whether these risks persist in the long-term is uncertain. Methods and Results We assessed all patients having percutaneous coronary intervention with coronary second- or first-generation drug-eluting stents in the Veterans Affairs healthcare system between 2006 and 2012 who were free of major ischemic or bleeding events in the first 12 months. The characteristics of patients who stopped DAPT prematurely (1-9 months duration), compared with >9 to 12 months, or extended duration (>12 months) were assessed by odds ratios (ORs) from multivariable logistic models. The risk of adverse clinical outcomes over a mean 5.1 years in patients who stopped DAPT prematurely was assessed by hazard ratios (HRs) and 95% CIs from Cox regression models. A total of 14 239 had second-generation drug-eluting stents, and 8583 had first-generation drug-eluting stents. Premature discontinuation of DAPT was more likely in Black patients (OR, 1.54; 95% CI, 1.40-1.68), patients with greater frailty (OR, 1.04; 95% CI, 1.03-1.05), and patients with higher low-density lipoprotein cholesterol, and less likely in patients on statins (OR, 0.87; 95% CI, 0.80-0.95). Patients who stopped DAPT prematurely had higher long-term risks of death (second-generation drug-eluting stents: HR, 1.35; 95% CI, 1.19-1.56), myocardial infarction (second-generation drug-eluting stents: HR, 1.46; 95% CI, 1.22-1.74), and repeated coronary revascularization (second-generation drug-eluting stents: HR, 1.24; 95% CI, 1.08-1.41). Conclusions Patients who stop DAPT prematurely have features that reflect greater frailty, poorer medication use, and other social factors. They continue to have higher risks of major adverse outcomes over the long-term and may require more intensive surveillance many years after percutaneous coronary intervention.