Inter-patient variability and impact of proton pump inhibitors on platelet reactivity after prasugrel

Although there is considerable variability of platelet reactivity among patients treated with clopidogrel, little is known about inter-individual differences and possible role of proton pump inhibitors (PPIs) after prasugrel. We defined the extent of inter-patient variability, and evaluated the impact of PPI interaction in prasugrel-treated patients with acute coronary syndrome (ACS). Between January 2010 and May 2011, 104 prospective, high-risk patients with ACS were recruited into this multicentre, prospective, observational study. Twelve to 24 hours after receiving 60 mg loading dose of prasugrel, light transmission aggregometry (LTA) and whole blood impedance aggregometry (Multiplate) were used to assess platelet activity. Platelet function measurements were repeated during maintenance phase on reduced (5 mg) or on conventional (10 mg) doses of prasugrel. High platelet reactivity (HPR) was defined according to the consensus document of the Working Group on High On-Treatment Platelet Reactivity (LTA:>46%; Multiplate:>47U). Compared to maintenance doses, 60 mg loading dose of prasugrel pro-vided significantly greater platelet reactivity inhibition (p