Abstract
Background: Reduced-dose prasugrel is widely used in East Asia for acute coronary syndrome (ACS), but real-world data in diverse Asian populations are limited. This study evaluated its effectiveness and safety in Taiwanese patients. Methods: The PROMISE-TW Registry was a multicenter, retrospective study including 1167 patients with ACS or chronic coronary syndrome (CCS) treated with reduced-dose prasugrel (20 mg loading, 3.75 mg maintenance) across 13 hospitals in Taiwan from 2018 to 2022. The primary endpoint was 1-year major adverse cardiovascular events (MACEs: cardiovascular death, non-fatal myocardial infarction, and non-fatal stroke). Secondary outcomes included composite ischemic events and major bleeding (BARC 3-5). Results: Among enrolled patients (mean age 63.9 years; 81.2% male; 83% ACS), percutaneous coronary intervention was performed in 90.8%. At one year, MACEs occurred in 1.9%, composite ischemic events in 8.2%, and major bleeding in 0.8%. Subgroup analysis identified prior stroke, diabetes, and chronic total occlusion intervention as predictors of bleeding. Male sex, chronic kidney disease, and left circumflex artery intervention predicted higher ischemic risk. Conclusions:Reduced-dose prasugrel provided effective ischemic protection and low bleeding rates in Taiwanese patients, especially those with ACS. These findings support the clinical utility of dose-adjusted prasugrel in East Asian populations and highlight the importance of individualized risk assessment.