Prognostic value of fully-automated left atrial strain in patients with asymptomatic chronic severe aortic regurgitation.

Background: To examine whether left atrial (LA) strain was associated with adverse outcomes in asymptomatic chronic aortic regurgitation (AR).

Methods: Asymptomatic patients with ≥moderate-severe AR were retrospectively identified from 2008 through 2022 from a university hospital. Apical 4-chamber left ventricular longitudinal strain (A4C-LVLS), LA reservoir (LASr), conduit (LAScd), and contractile strain (LASct) were measured using fully-automated software. Primary endpoint was all-cause death (ACD); secondary endpoints were heart failure (HF) development or aortic valve surgery (AVS).

Results: Of 352 patients (59 ± 17 years; 19 % female), the mean LV ejection fraction (LVEF) was 60 ± 8 %. The median follow-up during medical surveillance was 4.7 (interquartile range: 1.8-9.0) years; during which 68 patients died. Multivariable analysis adjusted for covariates showed that larger maximal LA volume index (iLAVmax), lower LASr and LASct were independently associated with ACD (all P ≤ 0.047); A4C-LVLS and LAScd were not (P ≥ 0.15). Besides, iLAVmax, LASr, and LASct provided incremental prognostic value over A4C-LVLS in terms of ACD (all P ≤ 0.048). HF symptoms occurred in 126 patients at a median of 2 years. Multivariable determinants for HF development included larger minimal LAV index, lower LASr and LASct (all P ≤ 0.03). Adjusted spline curves showed LASr <38-40 % and LASct <20-24 % were associated with increased risks of ACD and HF development, respectively. Using abovementioned LASr and LASct cutoffs, adjusted Kaplan-Meier curves risk-stratified patients for ACD successfully (P ≤ 0.02). Lower LASr was also independently associated with AVS (Hazard ratio per 1 % increase: 0.98)(P = 0.02).

Conclusions: In patients with asymptomatic AR, fully-automated LASr and LASct were robust markers for outcome determination; these markers may identify those who need timely surgical referral.