Heartburn - that burning sensation in the chest that occurs when stomach acid rises up into your esophagus - has absolutely nothing whatsoever to do with the heart. People with heartburn (that's a lot of us) are at no increased risk of developing heart disease. At least, not unless they're taking the most commonly used class of drugs for treating heartburn.
That drug class would be proton-pump inhibitors, or PPIs, and it includes omeprazole (Prilosec), lansoprazole (Prevacid), esomeprazole (Nexium) and a few more. All three are available over the counter. Although the labels direct users not to take these drugs for longer than a couple of weeks without consulting their physicians, people often pop them on a daily basis for months or years on end.
But a new PLOS ONE study, led by Stanford biomedical-informatics expert Nigam Shah, PhD, MBBS, and cardiovascular surgeon Nick Leeper, MD, shows a clear association between prior use of PPIs for heartburn and elevated risk of serious cardiovascular events including heart attacks. In a news release covering that "big data" study, which combed through nearly 3 million electronic health records to ferret out the PPI/cardiovascular-risk connection, I wrote:
... PPIs are among the world’s most widely prescribed drugs, with $14 billion in annual sales... In any given year, more than 20 million Americans - about one in every 14 - use PPIs... More than 100 million prescriptions are filled every year in the United States for PPIs, a class of drugs long considered benign except for people concurrently taking the blood thinner clopidogrel (Plavix). However, the new study upends this view: It indicates that PPI use was associated with a roughly 20 percent increase in the rate of subsequent heart-attack risk among all adult PPI users, even when excluding those also taking clopidogrel.
That increased risk was seen among younger adults (under age 45), too.
The study, in other words, found that everybody's cardiovascular risk goes up if they use PPIs. Now, a 20 percent increase in risk may not amount to much if your baseline risk is very low to begin with (say, that of a 20-year-old woman in top physical condition with no genetic predisposition to high blood pressure or elevated cholesterol). But for many of us, especially if we're middle-aged, a little pudgy, or struggling with hypertension or hypercholesterolemia, that 20 percent looms larger.
Importantly, people who take the second-most-widely prescribed class of drugs prescribed for heartburn, so-called H2 blockers, appear to suffer no ill effects from them in the cardiovascular-risk department, according to the study's findings. H2 blockers, which have been around longer than PPIs, are reasonably effective.
So, why do PPIs, but not H2 blockers, cause trouble? As I noted in my release:
The study’s findings lend support to an explanation for an untoward effect of PPIs on heart-disease risk proposed by Stanford scientists a few years ago. Research done then showed that PPIs impede the production of an important substance, nitric oxide, in the endothelial cells that line all of the nearly 100,000 miles of blood vessels in an averag adult’s body.
Nitric oxide relaxes blood vessels. So it figures that chronic use of a drug that shuts down that chemical's generation could cause chronic blood-vessel constriction and follow-on cardiovascular problems.
Read those labels, people.
Previously: How efforts to mine electronic health records are beginnning to influence critical care, New research scrutinizes off-label drug use and Damage to dead-cell disposal system may increase heart disease
Photo by John