Using e-cigarettes every day can almost double the chance of a heart attack, according to a new analysis of a survey of nearly 70,000 people, led by UC San Francisco researchers.
The study also showed that the double use of e-cigarettes and conventional cigarettes – the most common pattern among users of e-cigarettes – seems more dangerous than the use of either product. The study found that the risks are combined, so that daily use of both e-cigarettes and conventional cigarettes increases the risk of heart attacks by five times compared to people who do not use either product.
This is the first study on the relationship between the use of e-cigarettes and heart attacks and begins to fill the understanding of the effects of e-cigarettes on health in the long term. The study was published August 22, 2018, in the American Journal of Preventive Medicine. The data was first presented in Baltimore at the annual meeting of the Society for Research on Nicotine and Tobacco in 2018 in February.
"Most adults who use e-cigarettes continue to smoke cigarettes," says senior author Stanton Glantz, PhD, a UCSF professor of medicine and director of the UCSF Center for Tobacco Control Research and Education.
"Although people may think they are reducing their health risks, we discovered that the risk of a heart attack of e-cigarettes increases the risk of cigarette smoking," said Glantz. "Using both products at the same time is worse than using one of the two separately. Someone who continues to smoke every day while using e-cigarettes every day increases the risk of a heart attack by a factor of five."
But the survey also reported some good news when smokers quit:
"The risk of a heart attack starts to drop once you stop smoking," Glantz said. "Our results suggest that the same is true when they stop using e-cigarettes."
No difference between e-cigarette and cigarette use
Electronic cigarettes typically provide an aerosol of nicotine and other flavors by heating a liquid and are promoted as a safer alternative to conventional cigarettes, which generate the nicotine aerosol by burning tobacco.
Although e-cigarettes emit fewer carcinogens than conventional cigarettes, they both deliver ultra-fine particles – 1/50 to 1/100 the size of a human hair – and other toxins that are linked to increased cardiovascular and non-cancer lung disease risk. .
The new analysis included 69,452 individuals who were questioned through National Health Interview Surveys in 2014 and 2016, a cross-sectional study in which personal interviewers asked participants if they had ever used e-cigarettes and / or cigarettes and if they had ever had a doctor or other health professional told that they had a heart attack.
Of the 9,352 current and former e-cigarette users, 333 (3.6 percent) had a heart attack, with the highest percentage (6.1 percent) among those who used e-cigarettes daily. In the analysis, a quarter of the 2,259 people who currently used e-cigarettes were former smokers of conventional cigarettes and about 66 percent of the current users of e-cigarettes were also current cigarette smokers.
The researchers found that the overall risk of a heart attack was about the same for those who smoked cigarettes every day as those who switched to the daily use of e-cigarettes. For those who used both products on a daily basis, the risk of a heart attack was 4.6 times greater than in people who had never used either product.
The authors also said that although there was a "long-term effect" associated with being a former smoker, there was no significant increase in the risk of myocardial infarction for former or (sometimes) e-cigarette users. They suggested that the risks of using e-cigarettes could quickly disappear if someone stopped, that some people would experiment with e-cigarettes and stop before they cause permanent damage, or that e-cigarettes would last long enough have not been available. to cause permanent damage to the cardiovascular system.
"The only way to substantially reduce the risk of a heart attack is to stop using tobacco," Glantz said.
The authors noted that it was not known whether the heart attacks were related to the use of e-cigarettes, and that some heart attacks that have been reported probably occurred before e-cigarettes became available in the US (around 2009), would cause them to underestimate the effects of e-cigarettes on the risk of heart attack.
The co-authors of the paper are Talal Alzahrani, M.D., Ivan Pena, M.D., and Nardos Temesgen, M.D., all from George Washington University. The work of Glantz was supported by R01DAO43950 from the National Institute of Drug Abuse and P50CA180890 from the National Cancer Institute and the Food and Drug Administration Center for Tobacco Products.