Proton Pump Inhibitor and Clopidogrel Use After Percutaneous Coronary Intervention and Risk of Major Cardiovascular Events

Purpose Due to shared hepatic metabolism, concomitant medication with a proton pump inhibitor (PPI) and clopidogrel might reduce the effectiveness of clopidogrel in the prevention of cardiovascular events after percutaneous coronary intervention (PCI). We aimed to examine the risk of major cardiovascular events after PCI comparing patients who used clopidogrel together with PPI with those who used clopidogrel alone. Methods This Swedish nationwide cohort study included patients who received clopidogrel after primary PCI in 2005-2019. Patients were followed for up to 12 months after PCI. Data were retrieved from the Swedish Prescribed Drug Registry, Patient Registry, Cancer Registry, and Cause of Death Registry. Multivariable Cox regression provided hazard ratios (HRs) with 95% confidence intervals (CIs) for cardiovascular events comparing PPI users (exposed) with non-users of PPI (non-exposed). The HRs were adjusted for sex, age, comorbidity, calendar period, obesity, diabetes, anti-diabetic medication, tobacco-related diseases, hypertension, and congestive heart failure. Results The cohort included 99,836 patients who received clopidogrel after primary PCI. Among these, 35,772 (35.8%) received concomitant PPI. Compared to non-users, PPI users had increased adjusted HRs of all study outcomes, i.e., the main outcome myocardial infarction (HR = 1.23, 95% CI 1.15-1.32) and the secondary outcomes coronary heart disease (HR = 1.28, 95% CI 1.24-1.33), stroke (HR = 1.21, 95% CI 1.05-1.40), and death due to coronary heart disease (HR = 1.52, 95% CI 1.37-1.69). The results were similar in analyses including both primary and secondary PCIs. Conclusions In patients who receive clopidogrel after PCI, concomitant use of PPI seems to increase the risk of major cardiovascular events.