Users run a 'significant risk' of developing one of these conditions compared to non-smokers; e-cigarette smokers are 56 per cent more likely to have a heart attack and have a 30 per cent greater chance of suffering a stroke.
They are also 44 per cent more likely to suffer circulatory problems, including blood clots, and the chances of depression, anxiety and other emotional problems double, say researchers at the University of Kansas School of Medicine.
The rates are lower than seen among tobacco users—who run a 165 per cent risk of a heart attack and a 94 per cent chance of developing heart disease—but they are still more significant than many had believed.
The researchers looked at reports of more than 96,000 people, some of whom used e-cigarettes, and compared their health against tobacco smokers. "Cigarette smoking carries a much higher probability of heart attack and stroke than e-cigarettes but that doesn't mean vaping is safe," said researcher Mohinder Vindhyal.
All e-cigarette smokers ran some risk of developing one of the health problems, whether they used the devices every day or just occasionally, although the risk increased with the frequency of use.
E-cigarettes were launched in 2007, and sales have increased 14-fold with around one in 20 Americans now using them. Since launch, 460 brands and 7,700 flavours have been developed.