Fifty patients with STEMI, pretreated with intravenous aspirin, undergoing PPCI were randomized to receive prasugrel 60-mg LD (n = 25) or ticagrelor 360-mg LD (n = 25). Residual platelet reactivity was assessed by VerifyNow at baseline and 1, 2, 4, and 12 hours after drug LD.
At the time of LD, 90% of enrolled patients had an aspirin reactivity unit value <550. P2Y12 reaction units 1 hour after the LD (study primary end point) were 236 (129-289) and 248 (115-304) in the prasugrel and ticagrelor group, respectively (P = .899). High residual platelet reactivity (P2Y12 reaction units ≥240) was found in 43% and 56% of patients (P = .386) at 1 hour and in 30% and 32% of patients (P = .907) at 2 hours, respectively. There was no significant difference in bleeding, arrhythmias, or dyspnea episodes in the 2 groups.
In patients with STEMI undergoing PPCI, double (360 mg) ticagrelor LD failed to achieve a faster and more intense platelet inhibition as compared with the standard prasugrel LD. Intravenously administered aspirin allowed to achieve a very early inhibition of acid arachidonic pathway.