Introduction: Currently, there is an intense debate about whether comedication with proton pump inhibitors (PPIs) weakens the antiplatelet effect of clopidogrel in patients undergoing coronary stent implantation. Competing mechanisms on the hepatic cytochrome 2C19 level are proposed. The aim of this study was to assess the impact of PPI treatment on clopidogrel response by measuring the ex vivo platelet aggregation in patients with coronary intervention.
Methods: 1425 consecutive patients with symptomatic coronary artery disease undergoing percutaneous coronary intervention were enrolled in this single centre study. PPI comedication was defined as PPI intake > or =1 week prior to a 600 mg clopidogrel loading dose. PPI treatment was based on physician preference. Residual platelet aggregation (RPA) was measured by optical aggregometry. To correct for potential selection bias, propensity score matching was applied.
Results: RPA was significantly higher in PPI-treated patients compared with non-PPI-users (final aggregation 34.0% vs. 29.8%, p<0.001). Low responder defined as RPA in the upper tertile were more often found in PPI-users. After adjustment for relevant confounders, PPI treatment was independently associated with higher RPA-levels.
Discussion: We demonstrated that peri-procedural co-administration of PPIs significantly decreases the effect of clopidogrel on RPA. To assess if clopidogrel-PPI interaction results in a higher susceptibility for cardiovascular events remains subject to further investigations.
Copyright 2009 Elsevier Ltd. All rights reserved.