Determinants and Clinical Outcomes of Extended Dual Antiplatelet Therapy over 3 Years after Drug-Eluting Stent Implantation: A Retrospective Analysis

PURPOSE: Although current guidelines recommend the administration of dual antiplatelet therapy (DAPT) for up to 12 months after the implantation of a drug-eluting stent (DES), extended DAPT is frequently used in real-world practice. MATERIALS AND METHODS: From the Korean Multicenter Angioplasty Team registry, we identified a total of 1414 patients who used DAPT for >3 years after DES implantation (extended-DAPT group) and conducted a landmark analysis at 36 months after the index procedure. We evaluated the determinants for and long-term outcomes of extended DAPT and compared the occurrence of major adverse cardiovascular and cerebrovascular events (MACCE), defined as the composite of all-cause death, myocardial infarction, stent thrombosis, and stroke, between the extended-DAPT group and the guideline-DAPT group [DAPT <1 year after DES implantation (n=1273)]. RESULTS: Multivariate analysis indicated the occurrence of acute coronary syndrome as the most significant clinical determinant of the use of extended DAPT. Bifurcation, stent diameter ≤3.0 mm, total stented length ≥28 mm, and use of first-generation DESs were also significant angiographic and procedural determinants. MACCE rates were similar between the extended-DAPT group and the guideline-DAPT group in crude analysis [hazard ratio (HR), 1.08; 95% confidence interval (CI), 0.69–1.68; p=0.739] and after propensity matching (HR, 1.22; 95% CI, 0.72–2.07; p=0.453). Major bleeding rates were comparable between the two groups. CONCLUSION: In patients undergoing percutaneous coronary intervention, indefinite use of DAPT does not show superior outcomes to those of guideline-DAPT. Major bleeding rates are also similar.