Comparing E-Cigarettes and Traditional Cigarettes in Relation to Myocardial Infarction, Arrhythmias, and Sudden Cardiac Death: A Systematic Review and Meta-Analysis.

Background: The use of electronic cigarettes (e-cigarettes) as a perceived safer alternative to traditional cigarettes has grown rapidly. However, the cardiovascular risks associated with e-cigarettes compared to regular cigarettes remain unclear.

Objective: To systematically review and compare the cardiovascular outcomes of e-cigarette use versus traditional cigarette use, focusing on the risks of myocardial infarction, arrhythmias, and sudden death.

Methods: A systematic review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Peer-reviewed studies published in English were included if they reported cardiovascular outcomes related to e-cigarette or traditional cigarette use. A total of 20 studies were included, covering observational and interventional studies focusing on heart rate variability, myocardial infarction, arrhythmias, and sudden cardiac events. The quality of the evidence was assessed using the GRADE criteria, and data were extracted and analyzed based on the PICOS (Population, Interventions, Comparisons, Outcomes, and Study designs) framework.

Results: The systematic review found that both e-cigarettes and traditional cigarettes pose significant cardiovascular risks, with traditional cigarettes linked to a higher incidence of myocardial infarction, arrhythmias, and sudden cardiac death. E-cigarette users also face increased risks of arrhythmias and myocardial infarction compared to non-smokers, primarily due to the constituents of aerosolized e-liquid, including nicotine and flavorings, which contribute to adverse cardiac effects. Regular e-cigarette use, particularly in combination with traditional cigarette use, was associated with a heightened risk of myocardial infarction. Studies also reported heart function abnormalities, such as systolic and diastolic dysfunction, and reduced ejection fractions. Additionally, changes in heart rate variability, heart rate, and blood pressure were observed, indicating both acute and chronic effects of e-cigarettes on cardiovascular autonomic regulation.

Conclusions: While e-cigarettes may present a lower cardiovascular risk compared to traditional cigarettes, they are not without harm. Both products are linked to increased risks of myocardial infarction and arrhythmias, though traditional cigarettes pose a higher overall threat. Given the limitations in the current evidence base, particularly concerning the long-term effects of e-cigarette use, further research is needed to clarify these cardiovascular risks and inform public health guidelines.