E-Cigarette Use Linked to Higher Heart Attack Risk, Major Global Analysis Finds

Electronic cigarette use may be associated with a significantly higher risk of heart attacks, particularly among people with a history of smoking, according to a new large-scale scientific review published in BMC Public Health. The findings challenge the widespread perception of vaping as a harmless or low-risk alternative to traditional cigarettes.

The study, a systematic review and meta-analysis, pooled data from 12 independent observational studies involving hundreds of thousands of participants to assess whether e-cigarette use is linked to myocardial infarction (heart attack) and stroke, while carefully accounting for conventional cigarette smoking.

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Key Findings: Heart Attack Risk Stands Out

Researchers found that people who use e-cigarettes had 53% higher odds of experiencing a heart attack compared with non-users. Even after adjusting for conventional cigarette smoking—a major confounding factor—the association remained statistically significant, though weaker.

The most striking result emerged among former cigarette smokers who now vape. This group showed more than double the odds of a heart attack compared with people who neither smoke nor vape. Researchers caution that this elevated risk may reflect long-term damage from past smoking, ongoing nicotine exposure, or a combination of both.

By contrast, the analysis did not find a clear increase in stroke risk among all e-cigarette users as a whole. However, former smokers who switched to vaping showed a 73% higher likelihood of stroke, raising further concerns.

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Why This Research Matters

Cigarette smoking has long been established as a major cause of cardiovascular disease, including coronary artery disease, hypertension, and stroke. E-cigarettes were introduced and marketed as harm-reduction tools, often promoted as safer alternatives or smoking cessation aids.

However, e-cigarettes deliver nicotine by heating liquids containing propylene glycol, vegetable glycerin, and flavoring chemicals. When heated, these substances can produce aldehydes and other reactive compounds that may damage blood vessels and contribute to heart disease.

With vaping rates rising globally—especially among younger populations—clarifying its long-term cardiovascular effects has become a public health priority.

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How the Study Was Conducted

The researchers followed PRISMA 2020 guidelines, a gold standard for systematic reviews. They searched PubMed, the Cochrane Library, and Web of Science for studies published between January 2005 and June 2025.

To reduce bias:

• Studies with financial links to the tobacco industry were excluded

• Smoking history was treated as a key confounding variable

• Only studies reporting heart attack or stroke outcomes were included

The final analysis included:

• 430,875 participants for heart attack outcomes

• Over 1.1 million participants for stroke outcomes

Statistical results were calculated using random-effects models, which account for variation across studies.

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Stroke Results More Mixed

Unlike heart attack findings, the relationship between vaping and stroke was less consistent:

• Overall, e-cigarette use was not significantly linked to higher stroke risk

• After adjusting for smoking, results remained non-significant

• Elevated stroke risk was seen only among former smokers who currently vape

Among people who never smoked combustible cigarettes and only used e-cigarettes, no significant association was found for either heart attack or stroke. However, the authors stress that this conclusion is based on limited data and may be affected by misclassification of smoking status.

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Expert Interpretation and Limitations

The authors emphasize that the findings do not prove direct causation, as most included studies were observational. Residual confounding from past smoking, duration of exposure, and inaccurate self-reporting may still influence results.

Nevertheless, the consistency of increased heart attack risk—especially in former smokers—raises serious questions about the idea that e-cigarettes are a safe transition away from smoking.

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Implications for Public Health and Policy

The study adds to growing evidence that vaping should not be assumed to be cardiovascularly benign, particularly for people with a history of smoking. Health experts say the findings should inform:

• Smoking cessation guidelines

• Public health messaging

• Regulatory decisions on e-cigarette marketing and use

The authors call for long-term prospective studies to better isolate the independent effects of vaping and to track cardiovascular outcomes over time.