Does Vaping Really Cause Heart Attacks?

Does vaping double your risk of having a heart attack? That’s what the news stories say, based on a new study from California anti-smoking activist Stanton Glantz and three George Washington University students.

Here’s a random selection of headlines:

“Vaping every day could double your risk of a heart attack, new research suggests” (Business Insider)

“Vaping doubles chances of heart attack” (San Francisco Chronicle)

“Study: Heart attack risk doubles for e-cigarette users” (UPI)

“E-Cigarettes May Raise Risk for Heart Attack” (New York Times)

The Times article, by Nicholas Bakalar, was a virtual transcription of the University of California-San Francisco press release. The reporter didn’t even seek out opposing views — which is a shame because there is no shortage of experts who would be glad to dispute Glantz’s dubious claims, and they wouldn't be coil-building and vape-mod "experts." They'd be respected scientists.

Prof. Glantz is the career anti-smoking (and anti-vaping) activist based at UCSF, where he runs the Center for Tobacco Control Research and Education, one of the FDA-funded Tobacco Centers of Regulatory Science (TCORS). Glantz’s PhD in applied mechanics led to research on human heart tissue, and that earned him a professorship in cardiology. But his interest for most of four decades has been battling the tobacco industry. At least that’s what he thinks he’s doing.

The study, published in the American Journal of Preventive Medicine, is titled “Association Between Electronic Cigarette Use and Myocardial Infarction.” Myocardial infarction is the medical term for heart attack. The researchers used 2014 and 2016 data from the National Health Interview Survey. Participants in the survey were asked if they used e-cigarettes, and also if they had ever been told by a doctor that they had a heart attack.

The UCSF press release tells the story Glantz wants reporters to hear (and retell): “The researchers found that the total odds of having a heart attack were about the same for those who continued to smoke cigarettes daily as those who switched to daily e-cigarette use.” But that’s extremely deceptive, because smokers who switch to vaping still have the cumulative damage to their cardiovascular health caused by their past smoking. The authors couldn’t even be certain if vapers had their heart attacks after they started vaping.

An “association” doesn’t prove a causal connection. It means that some e-cigarette users had heart attacks at some point in their lives. It doesn’t necessarily mean they had heart attacks after they began vaping, because that question wasn’t asked. It may prove that more vapers have heart attacks than non-vapers, but that can be easily explained without assuming that vaping caused their heart attacks.

Most vapers are also current or ex-smokers. Smoking causes a lot of cardiovascular damage that can lead to heart attacks — even years after you quit smoking. If you smoke for 25 years and quit by switching to vaping, and then you have a heart attack years later, the explanation is probably your smoking history, not the vaping you did after you smoked for 25 years.

Glantz also seems to claim that "dual users" (people who smoke and vape) are at even higher risk, apparently because when smokers add vaping to their smoking regime they're still also smoking the same amount. But most people who do both are replacing some of their smoking with vaping, not simply adding one to the other.