Impaired left atrial strain predicts abnormal exercise haemodynamics in heart failure with preserved ejection fraction

Abstract

Background: Elevated left atrial (LA) pressure, particularly during exercise, is associated with symptomatic status and survival in patients with heart failure with preserved ejection fraction (HFpEF). We aimed to characterize the contribution of abnormal LA mechanical properties to exercise haemodynamics in HFpEF.

Methods and results: Simultaneous echocardiography and right heart catheterization were performed in 71 subjects with left ventricular ejection fraction ≥ 50% referred for assessment of exertional dyspnoea. According to haemodynamic evaluation, 49 patients were diagnosed with HFpEF [pulmonary capillary wedge pressure (PCWP) ≥ 15 mmHg at rest and/or ≥ 25 mmHg at maximal exertion] and 22 as non-cardiac dyspnoea. Apical two- and four-chamber views were used for blinded two-dimensional LA speckle tracking analysis. HFpEF was characterized by impaired LA reservoir (24.3 ± 9.6 vs. 36.7 ± 8.4%, P < 0.001) and pump strain (-11.5 ± 3.2 vs. -17.0 ± 3.4%, P < 0.001); and increased stiffness (0.8 ± 0.7 vs. 0.2 ± 0.1 mmHg/%, P < 0.001). Reservoir and pump strain correlated with exercise PCWP (r = -0.64 and r = 0.72, P < 0.001), and remained independent predictors after adjusting for left ventricular mass index, LA volume index, mean E/e' and systolic blood pressure (B = -0.66 and B = 1.41, respectively, P < 0.001). LA stiffness was strongly related to B-type natriuretic peptide levels (r = 0.73, P < 0.001; B = 173.0, P < 0.001). Reservoir strain at cut-off of ≤ 33% predicted invasively verified HFpEF diagnosis with 88% sensitivity and 77% specificity, providing a net reclassification improvement of 12% in comparison to the 2016 European Society of Cardiology criteria for non-invasive diagnosis of HFpEF.

Conclusions: Impaired LA reservoir and pump function and increased stiffness are associated with abnormal exercise haemodynamics in HFpEF. These markers provide significant HFpEF diagnostic utility in elderly ambulatory patients with dyspnoea.

Keywords: Exercise; Heart failure with preserved ejection fraction; Left atrial strain; Speckle tracking.