Alcohol is neither a risk factor nor a protective factor for sudden cardiac death and/or fatal ventricular arrhythmia; a population-based study with genetic traits and alcohol consumption in UK Biobank

Background The association between alcohol consumption and risk of sudden cardiac death and/or fatal ventricular arrhythmia remains controversial. Objective We analyzed the association between alcohol consumption, genetic traits for alcohol metabolism, and the risk of sudden cardiac death and/or fatal ventricular arrhythmia. Methods We identified 397,164 subjects enrolled between 2006 and 2010 from the UK Biobank database and followed them until 2021. Alcohol consumption was categorized as current nondrinkers (nondrinkers and ex-drinkers), mild drinkers, moderate drinkers, or heavy drinkers. Genetic traits of alcohol metabolism were stratified according to the polygenic risk score tertiles. The primary and secondary outcomes were a composite of sudden cardiac death and fatal ventricular arrhythmia, as well as their individual components. Results During the follow-up (median 12.5 years), 3,543 cases of clinical outcomes occurred. Although mild, moderate, and heavy drinkers showed deceased risks of outcomes compared with current non-drinkers, there was no prognostic difference among non-drinkers, mild drinkers, moderate drinkers, and heavy drinkers. Ex-drinkers showed increased risk in the univariate analysis, but the significance was attenuated after adjusting covariates (hazard ratio (HR) 1.19; 95% confidence interval [CI]: 0.94-1.50). As a continuous variable, alcohol consumption was not associated with clinical outcomes (HR 1.01; 95% CI 0.99-1.02). Consistent with these findings, there was no association between genetic traits for alcohol metabolism, and the risk of clinical outcomes. Conclusions Alcohol consumption was neither a protective nor a risk factor for sudden cardiac death or fatal ventricular arrhythmia. Genetic traits of alcohol metabolism were not associated with the clinical prognosis.