Use of proton pump inhibitors (PPIs) increase the risk of an adult experiencing a heart attack by 16-21% compared to those who don’t use commonly prescribed antacids, a large study has found. Findings from the study are published in PLOS One.

Previous research had shown PPIs could negatively affect the endothelium, which led scientists to believe that this may increase the risk for heart attack in anyone taking PPIs. The risk seemed to only apply to a narrow subset of patients with coronary artery disease taking antiplatelets to prevent future heart attacks.

But in the current study, researchers from Houston Methodist and Stanford University found a significant correlation between PPI exposure and the occurrence of heart attack after analyzing 2.9 million patients reflected in 16 million clinical documents; data was collected from two sources called the Stanford Translational Research Integrated Database Environment and Practice Fusion, Inc.

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They identified records of patients who were given PPIs or other drugs and experienced a major cardiovascular event. Data from patients who were given PPIs primarily for acid reflux with no history of heart disease showed an association with a higher rate of heart attacks with 1.16–1.21-fold increased risk. Patients who took H2 blockers, however, did not have an increased risk of a heart attack.

Future large, prospective, randomized trials are warranted to determine whether PPIs are harmful to a larger patient population, researchers concluded.

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