Effectiveness and Safety of Reduced Dose Prasugrel versus Standard Dose Ticagrelor in East Asian Patients With Acute Coronary Syndrome Undergoing Percutaneous Coronary Intervention

Background: Prasugrel and ticagrelor are potent P2Y12 inhibitors used in acute coronary syndrome (ACS) patients undergoing percutaneous coronary intervention (PCI). Reduced dose prasugrel (20 mg loading dose/3.75 mg maintenance dose) is used in some Asian countries because higher antiplatelet activity have been found in East Asians than that in Westerners.4 However, the effectiveness and safety between reduced dose prasugrel and standard dose ticagrelor in ACS patients is not fully understood.

Objectives: To compare the effectiveness and safety of reduced dose prasugrel and standard dose ticagrelor among ACS patients in an East Asian population.

Methods: This new-user designed retrospective cohort study used the Health and Welfare Database in Taiwan. We included patients with ACS undergoing PCI between January 1, 2018 and December 31, 2020 and discharged with dual antiplatelet therapy. Each patient had a maximum 9-month follow-up period. Two study groups were assessed, reduced dose prasugrel (exposure) and standard dose ticagrelor (reference) group. We used stabilized inverse probability of treatment weighting to balance the covariates between the two study groups. Primary effectiveness outcome was the composite of cardiovascular death, ischemic stroke, hemorrhagic stroke, transient ischemic attack, acute myocardial infarction, and revascularization; Primary safety outcome was the composite of intracranial hemorrhage and gastrointestinal bleeding. Cox-proportional hazard models were used to compare the outcomes between the two study groups. Subgroup analyses were performed according to age ( < 65 years or ≥65 years).

Results: We included 1,493 prasugrel users and 23,314 ticagrelor users to our study. There were no significant differences in the primary effectiveness outcome (Hazard ratio (HR):0.90; 95% CI: 0.78-1.03) and the primary safety outcome (HR:1.16; 95% CI: 0.69-1.94) between the two groups. In the subgroup analysis with aged < 65 years, reduced dose prasugrel was associated with a marginally better effectiveness (HR:0.82; 95% CI: 0.68-0.99) compared to standard dose ticagrelor.

Conclusions: Our study suggested that reduced dose prasugrel was as effective and safe as standard dose ticagrelor for East Asian ACS patients. Reduced dose prasugrel may be an optimal choice for East Asian ACS patients.