Recently the front page of virtually every major publication proclaimed that medicines used to treat acid reflux (proton pump inhibitors, or ppi’s) may cause heart attacks. Using “mined data” by scouring electronic medical records, researchers determined that use of ppi’s increase people’s risk of getting a heart attack by 16%. That day and the next, my email was pummeled by patients and families wondering if they should stop their prilosec or nexium lest a heart attack be around the corner. A 16% chance of getting a heart attack seemed very frightening.
I am not a fan of the overuse of ppi’s, and am aware of certain side effects from such use, but these drugs have helped many people avert troubling acid reflux, avoid ulcers, and overall feel better. So is it worth incurring the risk of a heart attack to achieve such benefits? And how reliable are these results?
The short answer is: this study proves nothing. First of all, 16% is a relative risk, or as we like to call it, a deceptive measure of risk. What is the actual risk of taking a ppi according to this study? The answer is 1/4300. Put simply, it would require 4300 people to take a ppi to put 1 person at risk for a heart attack. In other words, 99.98% of people who take ppi’s are not at risk for having a heart attack.
But it is even questionable if any ppi user is at risk for having a heart attack due to other confounding variables. The study’s authors claim that the excess risk of MI in ppi users is drug related because other people with acid reflux who use a different class of drugs (H2 blockers, such as zantac) do not have more heart attacks. But many more people with reflux use ppi’s than H2 blockers, especially people with more severe reflux. And people with severe reflux may be at higher risk of MI independent of ppi use, for many reasons. First, people with severe acid reflux who use ppi’s are more likely to smoke, drink alcohol in excess, eat poorly, be overweight, and use NSAIDS like motrin, all of which increase MI risk. Second, people with coronary artery disease (the condition that leads to heart attacks) are more likely to take aspirin, which can cause reflux, which can cause such people to use ppi’s; thus people with heart disease may be using ppi’s more than people without heart disease. Third, some people having heart pain may think it is acid reflux and start taking ppi’s. These people are at risk for having a heart attack, and they may be using ppi’s more than people at less risk, but the drug is not what puts them at higher risk of MI. In other words, in all these instances, the conditions and risks that prompt certain people to use ppi’s put them at risk for heart attacks, not the ppi’s themselves.
The fact that the ppi-MI link was deemed to be substantive and proven, so much so that it was front page and headline news all over the media, is endemic of the faulty information that is disseminated about health issues by the press. Rather than stating that there is a 16% increased risk of MI with ppi use (deceptive risk), responsible news organizations would have stated that the study showed that 1/4300, or .02%, of people using ppi’s may be at risk for having a heart attack (actual risk). Rather than stating that the drug itself is likely to cause heart attacks, responsible news organizations would have listed the many factors that could place people with acid reflux at higher risk of MI independent of ppi use. In the end, sensationalized and poorly presented medical information only leads to confusion among doctors and patients, and the inability for people to assess the actual risks and benefits of medical interventions. It is time that all of our media present medical information more responsibly.