Ticagrelor versus prasugrel in acute coronary syndrome patients with high on-clopidogrel platelet reactivity following percutaneous coronary intervention: a pharmacodynamic study
JACC Cardiovascular Interventions, 07/17/2012  Clinical Article

Alexopoulos D et al. – In patients with acute coronary syndrome (ACS) exhibiting high on–treatment platelet reactivity (HTPR) while on clopidogrel 24 h post–PCI, ticagrelor produces a significantly higher platelet inhibition compared with prasugrel.

• In a prospective, single–center, single–blind study, 44 (of 139 screened, 31.7%) ACS patients with HTPR while on clopidogrel 24 h post–PCI were randomized to either ticagrelor 90 mg twice daily or prasugrel 10 mg once daily for 15 days with a crossover directly to the alternate treatment for another 15 days.
• HTPR was defined as platelet reactivity units (PRU) ≥235 as assessed by the VerifyNow P2Y12 function assay.

• The primary endpoint of platelet reactivity at the end of the 2 treatment periods was lower for ticagrelor (32.9 PRU, 95% confidence interval [CI]: 18.7 to 47.2) compared with prasugrel (101.3 PRU, 95% CI: 86.8 to 115.7) with a least squares mean difference of –68.3 PRU (95% CI: –88.6 to –48.1; p < 0.001).
• The secondary endpoint of HTPR rate was 0% for ticagrelor and 2.4% for prasugrel (1 of 42, p = 0.5).
• No patient exhibited a major bleeding event at either treatment group.