Association between Electronic Cigarette Use and Myocardial Infarction: A Meta-meta-analysis

Abstract Background: Myocardial infarction (MI) is a global health concern with established risk factors including family history, dyslipidemia, diabetes, and smoking. However, the potential link between e-cigarettes and MI remains unclear. Objectives: This study conducted a meta-meta-analysis to assess the relationship between e-cigarette use and MI and to investigate whether e-cigarettes pose a lower MI risk compared to tobacco smoking. Methods: A literature search on PubMed/MEDLINE and Embase identified meta-analyses on e-cigarette use and MI. Methodological quality was assessed using the AMSTAR 2 framework. Statistical analyses with STATA 18 reported effect sizes as odds ratios (ORs) with 95% confidence intervals, alongside heterogeneity as measured by the I² statistic. A corrected covered area matrix was applied to evaluate publication overlap. Results: Despite limitations and publication overlap, a pooled analysis of three meta-analyses found that e-cigarette users had a higher risk of MI compared to nonusers (OR: 1.291; 95% CI: 1.106–1.507; I 2 = 79.6%; P = 0.007). However, a separate pooled analysis from two meta-analyses showed e-cigarette users had a lower risk of MI compared to traditional cigarette smokers (OR: 0.478; 95% CI: 0.324–0.703; I 2 = 87.8%; P = 0.004). Conclusion: The results highlight the complex risk profile of e-cigarette use. While e-cigarettes are associated with an increased risk of MI compared to nonuse, they may represent a low-risk alternative to traditional cigarette smoking. Further high-quality research is needed to clarify the long-term cardiovascular effects of e-cigarettes and their comparative safety.