Re-examining the Association Between E-Cigarette Use and Myocardial Infarction: A Cautionary Tale

Cross-sectional analyses have suggested that e-cigarette use, independent of combustible cigarette use, elevates the risk of myocardial infarction. Previous researchers confused their own models' assumptions that these risks were independent with the idea that their analyses validated the presence of independent risks. This study avoids this pitfall.

Cross-sectional analyses of the 2014-2019 National Health Interview Surveys (N=175,546) were conducted in 2020.

Logistic regressions found that e-cigarette use was associated with having had a myocardial infarction, but this association significantly varied on the basis of one's smoking history. With a host of demographic and clinical variables controlled, e-cigarette use was associated with lifetime myocardial infarction occurrence only among current smokers. A counterfactual analysis first removed all (current or former) e-cigarette‒using respondents who had suffered a myocardial infarction without a history of smoking. The independent-effects model used in previous research misleadingly indicated that daily vaping increases never smokers' odds of having had a myocardial infarction by 1.55 (95% CI=1.11, 2.15), even though no such myocardial infarction sufferers remained in the analyzed data. The association between myocardial infarction and vaping daily has shown a significant annual decline (AOR=0.81, 95% CI=0.67, 0.98).

There is no reliable evidence that e-cigarette use is associated with ever having had a myocardial infarction among never smokers. Contrary to concerns that the harms associated with e-cigarettes are only now emerging after more years of possible product use, the only evidence of time-dependent variation in the association between e-cigarette use and myocardial infarction ran counter to this possibility. The scientific community must insist that researchers engage in accurate public communication of peer-reviewed findings.