Effectiveness and Safety of Reduced‐Dose Prasugrel in an East Asian Population: PRASFIT‐ACS Emulation Using National Health Insurance Claims Data

Prasugrel is recommended for acute coronary syndrome (ACS) patients undergoing percutaneous coronary intervention (PCI). However, East Asians exhibit a stronger antiplatelet response, raising concerns about bleeding risks with standard dosing. This retrospective cohort study evaluated the real‐world effectiveness and safety of reduced‐dose prasugrel in an East Asian population by emulating the pivotal PRASFIT‐ACS trial using Taiwan's National Health Insurance claims data. In this study, ACS patients were classified into reduced‐dose prasugrel or clopidogrel groups post‐PCI. We estimated the intention‐to‐treat effect of initiating reduced‐dose prasugrel vs. clopidogrel on the risk of major adverse cardiovascular events (MACE) and the per‐protocol effect of treating with reduced‐dose prasugrel on major bleeding risk using Cox proportional hazard models. A total of 4833 ACS patients were analyzed, including 977 (20.2%) who received reduced‐dose prasugrel. Reduced‐dose prasugrel showed comparable effectiveness to clopidogrel in preventing MACE (HR: 0.96, 95% CI: 0.72–1.29) and did not increase bleeding risk (HR: 0.82, 95% CI: 0.36–1.90), consistent with PRASFIT‐ACS results (HR MACE : 0.85, 95% CI: 0.62–1.16; HR Bleeding : 0.82, 95% CI: 0.39–1.73). A significant reduction in cardiovascular mortality was observed (HR: 0.51, 95% CI: 0.29–0.89), differing from PRASFIT‐ACS findings (HR: 1.21, 95% CI: 0.48–3.06). Our results suggest that reduced‐dose prasugrel was effective in preventing thrombotic events in the Taiwanese population without significantly increasing bleeding risk. These findings align with pivotal trial outcomes while highlighting the importance of race‐specific dose adjustments to optimize ACS treatment strategies. Further research is needed to evaluate whether these results are applicable to other East Asian populations.