Differences in P2Y12 Reaction Units Between Prasugrel and Clopidogrel by Ischemic Cerebrovascular Disease Subtypes - Subanalysis From ACUTE-PRAS.

Background: We previously reported that prasugrel treatment resulted in stable inhibition of platelet aggregation compared with clopidogrel in patients with acute large artery atherosclerosis (LAA) or high-risk transient ischemic attack (TIA). However, the differences by disease subtypes were not assessed. This subgroup analysis of the open-label ACUTE-PRAS study examined differences in P2Y₁₂ reaction units between prasugrel and clopidogrel by disease subtypes (acute LAA and high-risk TIA).

Methods and results: We measured platelet reaction units (PRU) by disease subtypes for each treatment arm. Eighty-eight patients were included in each treatment arm in the full analysis. In the prasugrel group, there were 61 (69.3%) patients with LAA and 27 (30.7%) patients with high-risk TIA. In the clopidogrel group, there were 64 (72.7%) patients with LAA and 24 (27.3%) patients with high-risk TIA. Among patients with LAA, PRU at Day 5 were numerically lower in the prasugrel group than in the clopidogrel group (arithmetic mean±standard deviation at Day 5: 128.8±49.0 vs. 178.9±60.5). In contrast, PRU at Day 5 were similar between prasugrel and clopidogrel in patients with high-risk TIA.

Conclusions: Prasugrel may have the potential to elicit stronger platelet aggregation inhibitory effects compared with clopidogrel in patients with acute LAA.