Associations of alcohol consumption with left atrial morphology and function in a population at high cardiovascular risk

Abstract

BackgroundExcessive alcohol consumption has been associated with increased risk of atrial fibrillation, though the underlying mechanisms remain unclear. An enlarged left atrium and impaired left atrial function may lead to atrial fibrillation. The association of alcohol consumption with structural and functional left atrial measures, however, has received limited attention.MethodsWe studied a subset of 515 participants from the PREDIMED-Plus trial, a Spanish ongoing, multi-center randomized trial testing an intensive life weight loss intervention (ILI) with an energy reduced Mediterranean diet and physical activity promotion versus usual care andad libitumMediterranean diet recommendations for the primary prevention of cardiovascular disease in adults with the metabolic syndrome. Participants underwent transthoracic echocardiography (TTE) at baseline, year 3, and year 5 of the study. Outcomes of interest included volumetric (volume index) and functional (reservoir, conduit, and contractile strains) measures of the left atrium. Alcohol consumption was calculated through the use of validated food frequency questionnaires repeatedly collected every year and presented as drinks consumed per day (1 drink = 14 grams of alcohol). Confounder-adjusted multiple linear regression and mixed models were used to estimate the association of alcohol consumption (at baseline and over 5-years of follow-up) with left atrial volume and function at baseline and over the 5-year follow-up.ResultsMean alcohol consumption among 515 eligible participants (mean age: 65 years, 40% female) was 1.6 drinks/day. Cross-sectionally, higher alcohol consumption (modeled in 1 drink/day increases) was associated with larger left atrial volume (0.6 ml/m2, 95% CI 0.2, 1.1) and lower left atrial reservoir and contractile strain (-0.4%, 95% CI -0.8, 0.0, and -0.4, 95% CI -0.7, -0.1). Baseline alcohol consumption was not associated with changes in left atrial structure and function, but an increase in alcohol consumption (per 1 drink/day increase) during follow-up was associated with left atrial enlargement (0.7 mL/m2, 95% CI 0.2, 1.2) and, to a lesser extent, left atrial strain worsening (-0.3%, 95% CI -0.8, 0.2) over 5 years.ConclusionIn a population at high risk of cardiovascular disease, an increase of alcohol consumption was associated with left atrial volume enlargement and worsening atrial function, suggesting mechanistic information about potential pathways linking excessive alcohol consumption with atrial fibrillation risk.