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

Abstract

BackgroundTo examine whether left atrial (LA) strain was associated with adverse outcomes in asymptomatic chronic aortic regurgitation (AR). MethodsAsymptomatic 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). ResultsOf 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). ConclusionsIn 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.