Clinical outcomes of prolonged dual antiplatelet therapy after coronary drug-eluting stent implantation in dialysis patients

BACKGROUND: End-stage renal disease yields susceptibility to both ischemia and bleeding. The optimal duration of dual antiplatelet therapy (DAPT) after drug-eluting stent (DES) implantation is not established in dialysis patients, who are usually excluded from randomized studies. Since recent studies implied the benefits of prolonged DAPT >12 months in chronic kidney disease, we investigated the effectiveness and safety of prolonged DAPT in dialysis patients with higher cardiovascular risks. METHODS: In this nationwide population-based study, we analyzed dialysis patients who underwent DES implantation from 2008 to 2015. Continued DAPT was compared with discontinued DAPT using landmark analyses, including free-of-event participants at 12 (n = 2246), 15 (n = 1925) and 18 months (n = 1692) after DES implantation. The primary outcome was major adverse cardiovascular events (MACEs): a composite of mortality, nonfatal myocardial infarction, coronary revascularization and stroke. Major bleeding was a safety outcome. Inverse probability of treatment weighting Cox regression was performed. RESULTS: Mean follow-up periods were 278.3–292.4 days, depending on landmarks. Overall, incidences of major bleeding were far lower than those of MACE. Continued DAPT groups showed lower incidences of MACE and higher incidences of major bleeding, compared with discontinued DAPT groups. In Cox analyses, continued DAPT reduced the hazards of MACE at the 12- [hazard ratio (HR) = 0.74, 95% confidence interval (CI) 0.61–0.90; P = 0.003], 15- (HR = 0.78, 95% CI 0.64–0.96; P = 0.019) and 18-month landmarks (HR = 0.79, 95% CI 0.63–0.99; P = 0.041), but without a significant increase in major bleeding at 12 (HR = 1.39, 95% CI 0.90–2.16; P = 0.14), 15 (HR = 1.13, 95% CI 0.75–1.70; P = 0.55) or 18 months (HR = 1.27, 95% CI 0.83–1.95; P = 0.27). CONCLUSIONS: Prolonged DAPT reduced MACE without significantly increasing major bleeding in patients who were event-free at 12 months after DES implantation. In deciding on DAPT duration, prolonged DAPT should be considered in dialysis patients.