Researchers from Stanford University s Center for Bioinformatics Research, working with scientists from Houston Methodist Research Institute, used a proprietary data mining technology to assess millions of patient records to determine if there was any relationship between heartburn medications and heart risk. And they did indeed find signals of that link.
Led by Dr. Nigam H. Shah, the investigators assessed 2.9 million patient records and focused on the almost 300,000 who had heartburn (gastro-esophageal reflux disease) symptoms. They then pored through the records, seeking evidence of myocardial infarction: heart attack. They found that among patients on a proton-pump inhibitor (PPI), there was a 16-21 percent elevated risk of MI. As a control of sorts to eliminate the possibility that simply lowering the acid content of the stomach was a contributing factor, or that people with heartburn were in fact having angina-type discomfort indicative of heart disease they also sought evidence among patients on a different type of acid remedy, H2 blockers. They found no such increase in heart risk among the latter. (Focusing solely on MI deaths, they also found a doubling of the risk of cardiac mortality among PPI-users).
The drugs of concern here, PPIs, are multi-billion dollar sellers, products taken by millions of Americans. These include Nexium, Prilosec, Prevacid, Protonix, Aciphex, and are made mostly by AstraZeneca, Novartis and Proctor & Gamble. The H2 blockers Pepcid, Zantac, Axid and Tagamet were not found to be linked to heart troubles.
Besides needing a prospective, randomized controlled study to confirm (or refute) this important result, we can postulate a possible rationale for why such an effect might be valid. In 2013, some of these same authors published a study in Circulation showing that the PPI drugs reduce levels of nitric oxide a very important biomolecule which is involved in regulation of multiple physiological processes in the arterial walls of medium-sized blood vessels, causing them to constrict as well as enhancing platelet aggregation (stickiness). Both of these effects might lead to increased cardiovascular risk.
In an article on this study published in Forbes.com, ACSH advisor Dr. Robert Glatter, head of Emergency Medicine at New York s Lenox Hill Hospital, asked Dr. Nicholas Leeper, one of the study s authors, for his take-home message:
So, based on this study mining data, should PPIs have a black box warning, and should we consider stopping their use at this time?
No, Leeper stated emphatically. These findings identify an association, but do not prove causation. A prospective randomized study which evaluates the impact of PPIs on vascular health and future risk of heart attack is mandatory before we can recommend a definitive change in care, Leeper explained. We do believe, however, that these datasets suggest PPIs may not be as safe as previously thought and we encourage patients to discuss their own personal risk-benefit profile with their doctors.