Abstracts from Around the World

Recent data suggest that proton pump inhibitors (PPIs) may diminish the efficacy of clopidogrel. This study compared platelet aggregation and coronary endpoints in 2 studies comparing a new thienopyridine (prasugrel) to clopidogrel. Mean inhibition of platelet aggregation was significantly lower for patients on a PPI than for those patients not on a PPI 6 hours after a loading dose of clopidogrel (23% vs 35%; P = .02), but only a modest effect was seen with and without a PPI after the loading dose of prasugrel. Of 13,608 patients with acute coronary syndrome randomized into groups receiving either of the two agents, 33% were on a PPI at randomization, and aspirin was used in 85% or more in each group. No interaction was found between PPI use and risk of cardiovascular death, myocardial infarction, or stroke at follow-up. There was also no apparent difference in coronary endpoints based upon which PPI was used. Similar findings were noted with H2 receptor antagonists.