Prognostic value of left atrial strain quantification from 2D ultrasound imaging in post-ischemic heart failure patients: evidence from the REMODEL-HF study

Background. Left atrial (LA) function can be effectively assessed by measuring longitudinal LA strain (LAS) via two-dimensional speckle tracking echocardiography (2DSTE). Here, we test 2DSTE-based LAS as marker of different left ventricle (LV) remodeling patterns and as prognostic index in ischemic heart failure (HF) candidates to surgical ventricular reconstruction. Methods. We retrospectively considered ischemic HF patients with anterior (group A, n=130) or posterior (group P, n=48) LV remodeling. Based on 2D ultrasound, LV and LA morpho-functional parameters were quantified including reservoir (LAS(Res)), conduit (LAS(Cond)) and booster (LAS(Boost)) LAS. We tested their capability to discriminate between groups A and P, and their group-specific prognostic significance for the composite endpoint of death or HF re-hospitalization at follow-up (mean follow-up time=40 months, range 3-101 months). Results. Group A and group P displayed similar end-diastolic (p=0.89) and end-systolic (p=0.33) LV volume index, and LA volume index LAVi (p=0.44) corrected for the degree of mitral regurgitation. As compared to group P, group A revealed a significant reduction in LAS(Boost) (9.2 +/- 0.4% vs. 11.1 +/- 0.7%, p=0.04) and a nonsignificant reduction in LAS(Res) (16.9 +/- 0.7% vs. 19.3 +/- 1.1%, p=0.06). Kaplan-Meier curves showed that the median LAS(Res) and LAS(Boost) values effectively stratified patients based on their prognosis in the overall study population (Log-rank p=0.002 and Log_rank p<0.0001) and in group A, where the association was stronger for LAS(Boost) (Log-rank p<0.001) than for LAS(Res) (Log-rank p=0.013). Conclusions. 2DSTE-based LAS assessment is affordable, repeatable and non-invasive, and could add clinically-relevant mechanistic insight and prognostic value in the stratification of ischemic HF patients.