Lack of significant interactions between clopidogrel and proton pump inhibitor therapy: meta-analysis of existing literature

Abstract

Background: Published data regarding the effect of concomitant clopidogrel and proton pump inhibitor (PPI) therapy on cardiovascular outcomes have been conflicting.

Aim: To perform an updated meta-analysis in order to determine changes in risk differences (RD) between primary and secondary outcome analyses.

Methods: Primary analysis was based on definite vascular outcomes, including all cause mortality, cardiac death, myocardial infarction, and/or stroke. Secondary analysis also incorporated probable cardiac events, which included re-hospitalization for cardiac symptoms or revascularization procedures. RD were combined using a random-effects model.

Results: We reviewed 1,204 publications of which 26 studies (16 published articles, 10 abstracts) met inclusion criteria. The meta-analysis of outcomes from the two randomized controlled trials did not show an increased risk (RD 0.0, 95% CI -0.01, 0.01) for adverse outcomes. The meta-analysis of primary outcomes showed a RD of 0.02 (95% CI 0.01, 0.03) for all studies. The meta-analysis for secondary outcomes yielded a RD of 0.02 (95% CI 0.01-0.04) based on 19 published papers and abstracts. When primary and secondary outcomes were combined, the meta-analysis for published papers yielded an overall RD of 0.05 (95% CI 0.03-0.06).

Conclusions: In patients using concomitant clopidogrel and PPI therapy, the risk of adverse cardiac outcomes was 0% based on data from well-controlled randomized trials. Data from retrospective studies and the addition of probable vascular events significantly increased the RD estimates, likely due to lack of adjustment for potential confounders.