Aims: Daily low-dose aspirin is recommended for prevention of cardiovascular events in patients with coronary artery disease (CAD), and proton pump inhibitors (PPIs) are recommended to prevent or treat aspirin-associated gastrointestinal injury. Previous studies have reported contradictory findings regarding the risk of major adverse cardiovascular events (MACE) in patients who use PPI with aspirin therapy. We sought to examine associations between PPI use and MACE and all-cause mortality in aspirin-treated CAD patients.
Methods and results: Using electronic medical record and healthcare claims data, we conducted a retrospective population-based cohort study to examine patients 40 years or older with a diagnosis of CAD and documented aspirin use. Patients taking clopidogrel or other antiplatelet or anticoagulant agents were excluded. Risk of MACE and all-cause mortality associated with PPI use vs. no PPI use was analysed by Cox proportional hazards regression with standard covariate adjustment. Of the 2011 patients included in the study, 295 (14.7%) used a PPI. During a mean follow-up of 3.1 years, 294 patients [63 PPI users (21.4%) and 231 PPI non-users (13.5%)] experienced an MACE. In the adjusted model, the risk of MACE with PPI treatment was no different than without PPI treatment [hazard ratio (HR) 1.32 (95% confidence interval 0.8–2.4)]. Likewise, there was no difference between groups for risk of all-cause mortality; 201 patients [47 PPI users (15.9%) and 154 PPI non-users (9.0%)] died of any cause [HR 1.33 (0.9–1.9)]. Results were validated by robust propensity score-matching methods (n = 574).
Conclusions: No evidence was found that PPI use is associated with increased risk of MACE or all-cause mortality in aspirin-treated CAD patients.