Aug. 23 (UPI) -- If e-cigarettes users vape every day, they nearly double the risk of a heart attack, according to a new analysis of a survey.
In addition, the dual use of e-cigarettes and conventional cigarettes appears to be more dangerous than using either product alone. It increases the odds of a heart attack by 4.6 times, according to researchers at the University of California San Francisco, who published their findings Wednesday in the American Journal of Preventive Medicine.
The study was the first to examine the relationship between e-cigarette use and heart attacks.
The risk of heart attack, however, drops immediately after people stop smoking or refrain from using e-cigarettes.
"Most adults who use e-cigarettes continue to smoke cigarettes," Dr. Stanton Glantz, a UCSF professor of medicine and director of the UCSF Center for Tobacco Control Research and Education, said in a press release. "While people may think they are reducing their health risks, we found that the heart attack risk of e-cigarettes adds to the risk of smoking cigarettes."
With e-cigarettes, an aerosol of nicotine and other flavors are delivered by heating liquid, as compared to conventional cigarettes that generate the nicotine aerosol by burning tobacco.
E-cigarettes deliver lower levels of carcinogens than conventional cigarettes, however both contain ultrafine particles and other toxins that have been linked to increased cardiovascular and non-cancer lung disease risks.
Researchers analyzed medical data on 69,452 smokers aged 18 and older who participated in the National Health Interview Survey in 2014 and 2016. The U.S. Census Bureau conducts the surveys.
Of 9,352 current and former e-cigarette users in the study, 3.6 percent had experienced a heart attack at some point. The highest percentage -- 6.1 percent -- was among those who used e-cigarettes daily.
The researchers noted that some participants reported their heart attacks occurred before e-cigarettes became available in the United States around 2009.
One quarter of the 2,259 people who currently used e-cigarettes were former conventional smokers -- and about 66 percent of current e-cigarette users were also current cigarette smokers.
The total odds of a heart attack were about the same for those who continued to smoke cigarettes daily and those who switched to daily e-cigarette use.
"The only way to substantially reduce the risk of a heart attack is to stop using tobacco," Glantz said.