Effects of omeprazole or pantoprazole on platelet function in non-ST-segment elevation acute coronary syndrome patients receiving clopidogrel

Background： This study evaluated the effect of omeprazole or pantoprazole on platelet reactivity in non-STsegment elevation acute coronary syndrome（NSTE-ACS） patients receiving clopidogrel.Methods： Consecutive patients with NSTE-ACS（n =620） from general hospital of Shenyang Military Command were randomized to the omeprazole or pantoprazole（20mg/d） group（1：1）, and received routine dual antiplatelet treatment. Patients＇ reversion rate of adenosine diphosphate-induced platelet aggregation（ADP-PA） was assessed at baseline, 12 to 24 h after administration of medication, and after 72 h of percutaneous coronary intervention（PCI）. The primary endpoint of the study was platelet reactivity assessed with ADP-PA at 30 days after PCI. Adverse events（AEs） were recorded for 30-day and 180-day follow-up periods.Results： There were no significant differences between both the groups in platelet response to clopidogrel at 12–24h after drug administration（54.09%±18.90% vs. 51.62%±19.85%, P=0.12）, 72 h after PCI（52.15%±19.45% vs. 49.66%±20.05%, P=0.18）, and 30 days after PCI（50.44%±14.54% vs. 48.52%±15.08%, P=0.17）. The rate of AEs did not differ significantly between groups during the 30-day（15.2% vs. 14.8%, P=0.91） and 180-day（16.5% vs. 14.5%, P=0.50） follow-up periods after PCI.Conclusion： The addition of omeprazole or pantoprazole to clopidogrel did not restrict the effect of platelet aggregation by reducing the conversion of clopidogrel. Compared with clopidogrel alone, pantoprazole-clopidogrel and omeprazoleclopidogrel combinations did not increase the incidence of adverse clinical events during 30-day and 180-day follow-up periods after PCI.