Background: Excessive alcohol consumption has been associated with increased risk of atrial fibrillation, although 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.
Methods and results: We studied 503 participants from the PREDIMED-Plus (Prevención con Dieta Mediterránea) trial, a randomized trial testing intensive weight loss intervention with an energy-reduced Mediterranean diet and physical activity promotion in preventing cardiovascular disease in adults with metabolic syndrome. Participants underwent transthoracic echocardiography at baseline, year 3, and year 5 of the study. Outcomes of interest included volume index and reservoir, conduit, and contractile strains of the left atrium. Alcohol consumption was calculated through food frequency questionnaires and presented as drinks consumed per day. Multiple linear regression and mixed models estimated the association of alcohol consumption with left atrial measurements at baseline and through follow-up. Cross-sectionally, higher alcohol consumption (per 1 drink/day increases) was associated with larger left atrial volume (0.65 mL/m2 [95% CI, 0.18-1.11]) and lower left atrial reservoir and contractile strain (-0.44% [95% CI, -0.87 to -0.01]; and -0.44% [95% CI, -0.75 to -0.14]). Baseline alcohol consumption was not associated with changes in left atrial measurements, but increases in alcohol consumption (per 1 drink/day increase) during follow-up were associated with left atrial enlargement (0.71 mL/m2 [95% CI, 0.17-1.26]).
Conclusions: In a population at high cardiovascular risk, increased alcohol consumption was associated with left atrial enlargement and worsening atrial function.
Registration: URL: http://www.controlled-trials.com; Unique identifier: ISRCTN89898870.
Keywords: alcohol consumption; atrial fibrillation; atrial structure and function.