Long-Term Safety and Efficacy of Prolonged Dual Antiplatelet Therapy according to Baseline Anemia after Percutaneous Coronary Intervention

PURPOSE: We aimed to evaluate the outcomes of prolonged dual antiplatelet therapy (DAPT) depending on baseline anemia after percutaneous coronary intervention (PCI). MATERIALS AND METHODS: Among the 1470 study participants, 448 (30.5%) were classified as having baseline anemia. We categorized the study population according to baseline anemia and DAPT duration: ≤12-month (m) DAPT (n=226) vs. >12-m DAPT (n=222) in anemic patients, and ≤12-m DAPT (n=521) vs. >12-m DAPT (n=501) in non-anemic patients. RESULTS: During a follow-up of 80.8 (interquartile range 60.6–97.1) months, anemic patients showed a higher incidence of major adverse cardiovascular and cerebrovascular events (MACCEs) (26.9% vs. 17.1%, p<0.001) and major bleeding (9.8% vs. 5.1%, p=0.006). Among the non-anemic patients, prolonged DAPT was associated with a reduced rate of MACCEs [inverse probability of treatment weighting (IPTW) adjusted hazard ratio (HR), 0.78; 95% confidence interval (CI), 0.63–0.96; p=0.019] without an increase in major bleeding (IPTW adjusted HR, 1.12; 95% CI, 0.75–1.68; p=0.574). However, prolonged DAPT was not related to the incidence of MACCEs (IPTW adjusted HR, 1.11; 95% CI, 0.88–1.39; p=0.387), with increased major bleeding (IPTW adjusted HR, 2.01; 95% CI, 1.32–3.06; p=0.001) among anemic patients. CONCLUSION: Although extended DAPT led to a reduction in MACCEs in non-anemic patients, it was related to increased major bleeding without reducing MACCEs in anemic patients.