Left Atrial Strain in Acute Heart Failure: Clinical and Prognostic Insights

Aims: In acute heart failure (AHF), the consequences of impaired left atrial (LA) mechanics are not well understood. We aimed to define the clinical trajectory of LA mechanics by left atrial strain (LAS) analysis. Methods and results: 85 consecutive AHF patients with reduced, mildly reduced, and preserved left ventricular ejection fraction (LVEF) were enrolled in the LAS-AHF trial and underwent LA mechanics analysis by speckle tracking echocardiography. 77 patients were followed-up at 6 and 12- months. At hospital admission, discharge, 6 and 12-months post-discharge, LA reservoir function (LAS), LA pump strain, LAVi, LA stiffness, indicators of right ventricular (RV) and left ventricular (LV) function, congestion indexes (B lines, IVC, X-ray congestion score index) and biomarkers (NT-pro-BNP) were measured. The primary outcome was time to first event of re-hospitalization, worsening HF or cardiovascular death.From admission to discharge, RV function significantly improved after decongestion, while no significant differences were observed in LA dynamics and LV function. In sinus rhythm patients with mild or no mitral regurgitation, decongestion was associated with a significant improvement of LAS and LA pump strain rate during hospitalization. At 12 months, 24 CV events occurred and of LAS impairment at 12 months follow-up emerged as the most powerful predictor followed by NT-pro-BNP. Kaplan-Meier Curves showed a better survival for LAS >16%, improvement of LAS > 5% and a LAS/LAVi ratio >0.25%/ml/m2 compared to lower cutoff values (log-rank: HR 3.5 CI 95% 1.8-7.3, p = 0.004; log-rank: HR 3.6 CI 95% 2-7.9, p < 0.01; log-rank: HR 3.27 CI 95% 1.4-7.7, p = 0.007). Conclusions: In AHF of any LVEF, LA dynamics is highly predictive of re-hospitalization and cardiovascular outcome and allows to ease risk-stratification, potentially becoming an early reference target for improving long-term outcome.