Vaping products are not associated with increased heart attack incidence among people without a history of smoking combustible cigarettes, according to a new study. Published in the American Journal of Preventive Medicine, researchers also concluded that three previous studies claiming a link between e-cigarettes and heart disease wrongly included those who previously smoked cigarettes or were using both vaping and combustible products. One paper even included participants who had heart attacks before they had ever vaped.
“Previous researchers confused their own models’ assumptions that these risks were independent with the idea that their analyses validated the presence of independent risks,” the researchers wrote. “There is no reliable evidence that e-cigarette use is associated with ever having had a myocardial infarction among never smokers.”
Authored by Michael Siegel, a community health sciences professor at Boston University, and University of California, Berkeley, business professor Clayton Critcher, analyzed data from 175,546 respondents to the annual National Health Interview Survey from 2014 to 2019. They found that daily e-cigarette use was only associated with higher heart attack incidence among people who were also currently smoking combustible cigarettes (duel users)—and that there was no evidence at all for increased risk among vapers who had never smoked combustible cigarettes.
The researchers state that the initial study had drawn its conclusions about a perceived cause (vaping) and effect (heart attack) without factoring in a key variable (smoking). Critcher and Siegel acknowledge that a more thorough analysis of previous research would have noted that e-cigarettes are relatively new, limiting the ability to assess long-term health effects and make comparisons with combustible tobacco smoking, in an article with Filter. However, the findings of previous research that e-cigarette use in of itself causes heart attacks is fundamentally flawed.
A 2018 study, also published in the American Journal of Preventive Medicine, claimed that daily vapers increased their odds of heart attack. However, the study only included participants who used both e-cigarettes and combustible cigarettes—none who used e-cigarettes alone. Suspicious of that methodology, a different group of researchers published a reply, arguing the importance of examining the purported link among people who had never smoked combustible cigarettes. Authors of the original study then published a reply to that reply, arguing that such a distinction wasn’t necessary.
In the meantime, two (one, two) other papers were published based on the original paper’s claims, lending further harmful legitimacy to the idea of a link between e-cigs and heart attacks, according to Kevin Garcia writing for Filter.
The second of those two papers was coauthored by the former prominent tobacco harm reduction opponent Stanton Glantz. It was retracted in 2020 for basing its claim that vaping caused heart attacks on evidence that included heart attacks from before the participants had even started vaping. Three weeks after the American Heart Association’s journal retracted the vaping study, academics and health experts began pushing for another influential peer-reviewed medical journal to retract another Glantz study.