Speckle Tracking-Derived Left Atrial Stiffness Predicts Clinical Outcome in Heart Failure Patients with Reduced to Mid-Range Ejection Fraction

Background and Aim: Left atrial stiffness (LASt) is an important marker of cardiac function, especially in patients with heart failure (HF); it explains symptoms on the basis of pressure transfer to the pulmonary circulation. The aim of this study was to evaluate the relationship between LASt and cardiac events (CE) in HF patients with reduced to mid-range ejection fraction. Methods: The study included 215 consecutive ambulatory HF patients with ejection fraction (EF) < 50% (162 HF reduced EF and 53 HF mid-range EF) of mean age 66 ± 11 years and 24.4% females. Peak LA strain (PALS) was measured by speckle tracking echocardiography and E/e’ recorded from the apical four-chamber view. Non-invasive LASt was calculated using the equation: LASt = E/e’ ratio/PALS. Documented cardiac events (CE) were HF hospitalization and cardiac death. Results: During a median follow up of 41 ± 34 months, 65 patients (30%) had CE. In multivariate analysis model, only raised LV filling pressure (E/e’) (OR = 0.292, (95% CI 0.099 to 0.859), p = 0.02), peak pulmonary artery pressure (PAP) (OR = 1.050 (1.009 to 1.094), p = 0.01), PALS (OR = 0.932 (0.873 to 0.994), p = 0.02) and LASt (OR = 3.781 (1.144 to 5.122), p = 0.001) independently predicted CE. LASt ≥ 0.76% was the most powerful predictor of CE, with 80% sensitivity and 73% specificity (AUC 0.82, CI = 0.73 to 0.87, p < 0.001) followed by PALS ≤ 16%, with 74% sensitivity and 72% specificity (AUC 0.77, CI = 0.71 to 0.84, p < 0.001). These results were consistent irrespective of EF (p < 0.05). Conclusion: In this cohort of ambulatory HFrEF and HFmrEF patients, LASt proved the most powerful predictor of clinical outcome.