One of the largest studies of its kind has found that using electronic cigarettes can lead to a dramatic increase in the user’s odds of having a heart attack, coronary artery disease, and depression.

The new research, presented at the American College of Cardiology (ACC) 2019 Annual Scientific Session, found that the trend may not be as healthy of an alternative to smoking as many have argued.

“Until now, little has been known about cardiovascular events relative to e-cigarette use," study lead author Mohinder Vindhyal, MD, assistant professor at the University of Kansas School of Medicine Wichita, said in a statement. "These data are a real wake-up call and should prompt more action and awareness about the dangers of e-cigarettes."

Currently, an estimated 1 out of every 20 Americans reportedly use e-cigarettes, and sales are 14 times greater than they were in 2007 when e-cigarettes were introduced. The devices work by heating the e-liquid, which may contain a combination of nicotine, solvent carriers, a number of flavors, and other chemicals, to a high enough temperature to create an aerosol that is then inhaled.

While their popularity has exploded in recent years, e-cigarettes are the subject of debates because they are often touted as being a healthier alternative to smoking tobacco.

Vindhyal and his team included data from 96,467 respondents from the National Health Interview Survey, a Centers for Disease Control and Prevention-fielded survey of Americans, from 2014, 2016, and 2017; the 2015 study was not included as it did not include e-cigarette related questions.

The study found that, compared with nonusers, e-cigarette users were 56% more likely to have a heart attack, 30% more likely to suffer a stroke, 44% more likely to suffer from circulatory problems, and 10% more likely to contract coronary artery disease. They were also twice as likely to suffer from depression or anxiety.

Most of these associations proved true when controlling for other known cardiovascular risk factors. After adjusting for variables, e-cigarette users were still 34% more likely to suffer from a heart attack, 25% more likely to have coronary artery disease, and 55% more likely to suffer from anxiety or depression. Stroke, high blood pressure and circulatory problems were not statistically different between the 2 groups.

Investigators dove deeper into the subject by examining how health outcomes are impacted by the frequency at which somebody uses e-cigarettes. Daily e-cigarette users had higher odds of heart attack, coronary artery disease, and depression or anxiety. Those who reported only using it some days still had higher odds of heart attack and depression or anxiety compared to nonusers, with only a trend towards coronary artery disease.

This could be a result of decreased toxic effects of usage, early dissipation of the toxic effects or that is has not been studied long enough to show permanent damage to portray cardiovascular disease morbidity, the team noted.

They also compared data for reported tobacco smokers and nonsmokers. Traditional tobacco cigarette smokers are 165% more likely to have a heart attack, 94% more likely to develop coronary artery disease, and 78% more likely to suffer from a stroke than nonsmokers.

They found that smokers were also more likely to have high blood pressure, diabetes, circulatory problems, and depression or anxiety.

“Cigarette smoking carries a much higher probability of heart attack and stroke than e-cigarettes, but that doesn’t mean that vaping is safe,” Vindhyal explained.

The study, “Impact on Cardiovascular Outcomes among E-Cigarette Users: A review from National Health Interview Surveys,” was presented at ACC 2019.