Abstract Body (Do not enter title and authors here): Introduction:
E-cigarette use, promoted as an alternative to traditional cigarette smoking, may have long-term clinical cardiovascular effects, including arrhythmias that have not yet been studied. Even though mouse models have shown significantly increased susceptibility to atrial fibrillation and ventricular tachycardia in rats exposed to e-cigs, there are no extensive human studies that investigate the association between e-cigarette use and atrial fibrillation in the US population. We sought to determine if e-cigarette use is associated with incident atrial fibrillation.

Methods:
This study was a longitudinal prospective study of participants enrolled in the NIH-sponsored ‘All of Us’ research study program. We excluded participants without electronic health records (EHR) and those with a diagnosis of Atrial fibrillation/flutter at baseline. We identified participants who had e-cigarette use at baseline using the Population Assessment of Tobacco and Health-styled questionnaire. We analyzed the association between both current and former e-cigarette use and incident atrial fibrillation using the Cox proportional hazards model adjusting for age, sex, race, ethnicity, income, education, alcohol use, diabetes mellitus, hypertension, dyslipidemia, BMI and other tobacco products (smokeless tobacco, cigar, hookah, and cigarette).

Results:
Of the 144, 743 participants eligible for the study at baseline, there were 2191 events of atrial fibrillation identified with a median follow-up time of 46 months. The mean age was 52 years; 21% were Blacks, 72.0% were White, and 3.5% were Asian. 2.6 % were of Hispanic ethnicity. 3.8%, 12.0%, and 84.2% were current, former, and never users of electronic cigarettes. Current and former use of e-cigarettes was not associated with incident atrial fibrillation after adjusting for confounders [aHR for current users= 0.77, 95%CI 0.52-1.12; for former users= 1.06, 95%CI 0.87 - 1.29]

Conclusion:
We did not find an association between e-cigarette use and incident atrial fibrillation or flutter. Further studies are needed in different populations to corroborate our findings.