Abstract P117: Elevated Liver Transaminases are Associated with an Increased Risk of Atrial Fibrillation

Background: For the management of an initial episode of atrial fibrillation (AF), guidelines recommend assessment of liver function tests; nonetheless, the rationale and supporting evidence for the recommendation remain unclear. We tested the hypothesis that elevated liver transaminases, assessed by alanine transaminase (ALT) and aspartate transaminase (AST) are associated with the incidence of AF in a community-based cohort. Methods and Results: From the Framingham Heart Study Original and Offspring cohorts we investigated 3779 participants (mean age 65±10 years, 56.8% females). After up to 10 years of follow-up (29,099 person years), 383 individuals developed AF. We used Cox proportional hazards models to assess the association between liver transaminases and AF incidence, and adjusted the model for established AF risk factors and alcohol consumption. Both ALT and AST showed significant association with incident AF (Table). When we excluded participants with moderate / severe alcohol consumption, the associations for ALT and AST remained consistent (Table). Additional adjustment for C-reactive protein (inflammatory marker) only mildly lowered the effect estimates for both transaminases, but decreased the level of significance (Table). We additionally estimated the ability of transaminasess to predict AF risk. When assessed by the continuous net reclassification improvement, both ALT and AST marginally improved AF risk prediction [ALT: 0.18 (95% confidence interval, 0.07-0.29; p=0.002); AST: 0.16 (95% confidence interval, 0.04-0.28; p=0.003)]. Conclusions: Higher mean levels of ALT and AST, are associated with the incidence of AF, even when adjusted for various established AF risk factors. However, transaminases contribute only subtly towards an improvement in AF risk prediction. Pathophysiologic mechanisms explaining the association are uncertain and merit further investigation.