Proton pump inhibitors linked to increased risk of heart attack

By Sally Robertson, B.Sc.Jun 11 2015

People who use proton pump inhibitors (PPIs) are up to 21% more likely to experience a heart attack than people who do not use the antacids, according to researchers from Houston Methodist and Stanford University, California.

Our results demonstrate that PPIs appear to be associated with elevated risk of heart attack in the general population," says Nigam Shah, lead author of the paper and assistant professor of biomedical informatics at Stanford.

The findings come from a study of 16 million clinical documents representing 2.9 million people. Shah and team collected data about 1.8 million Stanford hospital and clinical patients and 1.1 million patients from a Web-based electronic medical records company. The data were scanned for patients who had been prescribed PPIs or other antacids such as H2 blockers to see whether any major cardiovascular events were mentioned in their records.

As reported in PLOS ONE, the use of PPIs was associated with a 16 to 21% increased risk of myocardial infarction.

"Our report raises concerns that these drugs – which are available over the counter and are among the most commonly prescribed drugs in the world – may not be as safe as we previously assumed," says principal investigator Nicholas Leeper.

Had they been in place, pharmacovigilance algorithms could have flagged this risk as early as the year 2000,” the researchers comment.

The team also found that the use of H2 blockers was not associated with any increased risk of a cardiovascular event.

Estimates from the Food and Drug Administration (FDA) show that about one in 14 Americans have been prescribed PPIs and in 2009, PPIs were the third most commonly used drug in the U.S. The drug is prescribed to treat various disorders such as gastro-esophageal reflux disease (GERD), Helicobacter pylori infection and Barrett’s esophagus. Examples of brand names for PPIs include PrevAcid, Prilosec and Nexium and examples of H2 blockers are Zantac and Tagamet.

The researchers say they plan to conduct a large, randomized trial to confirm whether PPIs are harmful in a broader patient population.