Left atrial strain measured by three-dimensional echocardiography predicts atrial fibrillation in the general population

Background: Left atrial (LA) strain by three-dimensional echocardiography (3DE), has been proposed as a more accurate measure of LA function, providing incremental prognostic benefits over traditional two-dimensional approaches. Objectives: Our aim was to evaluate the prognostic value of LA strain by 3DE in predicting incident atrial fibrillation (AF) in the general population. Methods: The study included 4466 participants from a prospective longitudinal cohort study in the general population, among these 3DE LA strain was analysed in 1935 participants. The endpoint was incident AF. Adjustments were made for the CHARGE-AF clinical risk score. Results: Mean age was 54 +/- 17 years, 43 % were male. During a median follow-up time of 4.8 years (interquartile range 4.3-5.5 years) 59 participants (3.0 %) developed AF. In univariable analysis, all three parameters were associated with incident AF (p value for all <0.01). After multivariable adjustments, only LA reservoir strain (LASr) and LA contractile strain (LASct) were associated with incident AF (LASr: HR 1.12 (1.07-1.17), p < 0.001, per 1 % decrease; LASct: HR 1.16 (1.09-1.24), p < 0.001, per 1 % decrease), whereas LA conduit strain (LAScd) was not (HR 1.04 (0.98-1.10), p = 0.17, per 1 % decrease). Both LASr (continuous net reclassification index 0.37 +/- 0.14; p = 0.003) and LASct (continuous net reclassification index 0.41 +/- 0.14; p = 0.002) provided incremental prognostic information beyond the CHARGE-AF risk score. Conclusion: LASr and LASct measured by 3DE are independently associated with incident AF and provided incremental prognostic information beyond existing risk scores.