Abstract 18784: Impaired Left Atrial Strain is a Risk Factor for New-Onset Atrial Fibrillation

Abstract

Introduction: Atrial fibrillation (AF) is the most common cardiac arrhythmia, affecting millions of individuals. Left atrial (LA) strain, a measure of LA function and remodeling, holds potential as a prognostic indicator for AF development. We aimed to examine whether LA strain is associated with new onset AF. Methods: We performed a nested case-control study within an electronic health record-based longitudinal cohort of primary care patients from a multi-institutional healthcare system spanning 2001 to 2018. Cases included patients who developed new-onset AF during a follow-up period of 7.3 years and had undergone transthoracic echocardiography (TTE) within three years of the follow-up start. Several LA strain parameters were compared between the case and control groups, including Peak Atrial Longitudinal Strain (PALS), Left Atrial Conduit Strain (LACS), and Peak Atrial Contraction Strain (PACS). Results: The study included 216 patients who developed AF during follow-up each matched with a corresponding age- and sex-matched control without AF. The AF group had significantly lower PALS (25.9 ± 8.9 vs. 34.3 ± 10.4, p<0.001) and LACS (13.6 ± 5.2 vs. 19.9 ± 7.6, p<0.001) compared to the non-AF group. Subgroup analyses of AF patients, stratified by the time to AF development, revealed more substantial differences between the AF and non-AF groups when the initial TTE was conducted closer to the onset of AF. Specifically, when the TTE was performed within 2 years prior to AF onset, the disparities in LA strain parameters were more pronounced compared to TTEs conducted between 2-5 years prior or beyond 5 years prior to AF onset. Conclusions: Impaired left atrial strain is strongly associated with new-onset AF, particularly when measured 2 years prior to AF onset, indicating a higher risk of developing AF in the near future. Incorporating LA strain assessment into clinical decision-making can enhance the evaluation of individuals at risk for AF.