E-cigarettes should not be recommended for smoking cessation purposes as they increase the risk of heart attack, a study has warned.
Daily e-cigarette users were almost twice as likely to have a heart attack compared with those who had never used e-cigarettes, according to the research.
The findings come after a Government report released in August recommended that patients should switch to e-cigarettes if it was not possible to quit smoking altogether.
The new study, carried out by researchers at George Washington University in Washington, used data from just under 70,000 people interviewed in a US national health survey in 2014 and 2016.
They found that patients who said they used e-cigarettes every day were 1.8 times as likely to have a heart attack compared to those who never used them.
The risk remained similar whether or not other variables such as frequency of normal cigarette use were factored in, suggesting an independent association between e-cigarette use and heart attack.
‘Former’ or ‘some days’ e-cigarette use was not significantly associated with increased heart attack risk. However, dual daily e-cigarette and cigarette use was associated with an almost five-fold increase in risk.
The paper, published in the American Journal of Preventive Medicine, said: ‘Daily e-cigarette use is associated with increased odds of [myocardial infarction] independent of and in addition to the risks associated with smoking and other risk factors.
‘Dual use of e-cigarettes and conventional cigarettes – the most common use pattern among e-cigarette users – is more dangerous than using either product alone. From these findings, recreational use of e-cigarettes or use of e-cigarettes for smoking cessation should not be recommended.’
The authors acknowledged that since it was not known when heart attacks occurred relative to e-cigarette use, it’s possible that some patients had a heart attack before they started using an e-cigarette as a cessation aid, meaning that the risk may be attributed to them being a former smoker rather than to using an e-cigarette.
It comes as a Public Health England evidence review concluded in February that e-cigarettes could be helping 20,000 a year to quit smoking and suggested that the evidence for providing e-cigarettes to NHS patients was ‘compelling.’
NICE guidelines, updated in March this year, only says GPs should discuss the pros and cons of e-cigarettes with patients considering them as a smoking cessation aid (see box).
What NICE guidance says
For people who smoke and who are using, or are interested in using, a nicotine-containing e‑cigarette on general sale to quit smoking, explain that:
- although these products are not licensed medicines, they are regulated by the Tobacco and Related Products Regulations 2016;
- many people have found them helpful to quit smoking cigarettes;
- people using e‑cigarettes should stop smoking tobacco completely, because any smoking is harmful;
- the evidence suggests that e‑cigarettes are substantially less harmful to health than smoking but are not risk free;
- the evidence in this area is still developing, including evidence on the long-term health impact.