'Evidence That e-Cigs Cause Heart Attacks' Retracted

Ivan Oransky, MD, and Ellie Kincaid

February 19, 2020

A study published last year touted by its coauthor as "more evidence that e-cigs cause heart attacks" has been retracted, following intense criticism.

The article, in the Journal of the American Heart Association (JAHA), was written by Dharma Bhatta, PhD, and Stanton Glantz, PhD, of the University of California, San Francisco, and concluded that, "Some‐day and every‐day e‐cigarette use are associated with increased risk of having had a myocardial infarction, adjusted for combustible cigarette smoking."

However, Brad Rodu, DDS, a professor at the University of Louisville who comments frequently on vaping, pointed out shortly after the paper was published that "the majority of the 38 patients in the study who had heart attacks had them before they started vaping," making the findings "false and invalid," as USA Today reported at the time.

In a retraction notice published yesterday, JAHA said that editors had asked Bhatta and Glantz to repeat their analyses, but that the coauthors were unable to because they no longer had access to the data that they had used. 

Glantz, who has received tens of millions of dollars in grant funding to study tobacco control, told Retraction Watch that he and Dharma "stand behind the paper as published."

In a blog post published shortly after the retraction, Glantz wrote: "The problem is that, during the process of revising the paper in response to the reviewers, we reported some sample size numbers without securing advance approval from the University of Michigan, who curates the [Population Assessment of Tobacco and Health] PATH restricted use dataset. This was a blunder on our part. As a result, the University of Michigan has terminated access to the PATH restricted use dataset, not only for Dr. Bhatta and me, but for everyone at UCSF."

However, Glantz wrote that "doing the additional alternative analysis will not change the main analysis in the paper, which the reviewers and editors accepted."

"How Preliminary These Data Are"

The retracted paper appears to have had accurate data, Michael Blaha, MD, MPH, director of clinical research for the Johns Hopkins Ciccarone Center for the Prevention of Cardiovascular Disease, wrote to Medscape Medical News in an email, but it "may have been missing contextual data that may have tempered conclusions." 

Electronic cigarette use and heart disease are associated in cross-sectional studies, "which are very limited and must be interpreted with caution," Blaha said, as these studies cannot establish temporality and causality.

Researchers do not yet have studies examining the incidence of heart disease in chronic, long-term users of electronic cigarettes, though "very preliminary" data "suggest possible links between e-cigarette use and coronary heart disease, acute and chronic lung diseases, and asthma," he added. 

Clinicians should use appropriate caveats when talking to patients about potential effects of e-cigarettes, Blaha said. "We must be careful not to overstate, or understate, what we currently know about potential links between electronic cigarettes and heart disease," he said. "Cardiologists need to understand how preliminary these data are."

Ivan Oransky, MD, is vice president of editorial at Medscape and co-founder of Retraction Watch. Ellie Kincaid is Medscape's associate managing editor and has previously written about healthcare for Forbes, the Wall Street Journal, and Nature Medicine.

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