Impaired Right Atrial Reserve Function in Heart Failure with Preserved Ejection Fraction

Abstract

Background: Patients with heart failure with preserved ejection fraction (HFpEF) have multiple cardiac reserve limitations during exercise. However, no data are available regarding right atrial (RA) reserve capacity in HFpEF. The aim of this study was to determine the association of RA reserve impairments with right ventricular function and exercise capacity in HFpEF and to explore its diagnostic value.

Methods: Patients with HFpEF (n = 89) and control subjects without heart failure (n = 108) underwent bicycle exercise echocardiography. RA reservoir, conduit, and booster pump strain at rest and during exercise were measured using speckle-tracking echocardiography. In a subset, simultaneous expired gas analysis was performed to measure peak oxygen consumption.

Results: At rest, RA reservoir strain was lower in patients with HFpEF than control subjects (27.0 ± 17.1% vs 38.6 ± 17.1%, P < .0001), while RA conduit and booster pump strain were similar between groups. During peak exercise, patients with HFpEF displayed marked reserve limitations in RA reservoir and booster pump function compared with control subjects, and the differences remained significant even after adjusting for confounding factors. During peak exercise, RA reservoir and booster pump strain were correlated with right ventricular systolic function. Lower RA booster pump strain during exercise was also weakly associated with lower cardiac output (r = 0.34, P < .0001) and reduced peak oxygen consumption (r = 0.47, P < .0001). RA reservoir strain during exercise had incremental diagnostic value to differentiate patients with HFpEF from control subjects over the established HFpEF diagnostic algorithms and left-sided strain parameters.

Conclusions: Limitations in RA reservoir and booster pump function during exercise are present in patients with HFpEF, and the severity is associated with right ventricular systolic reserve, poor cardiac output, and depressed exercise capacity. Exercise RA strain assessment may help in the diagnosis of HFpEF.

Keywords: Exercise; Heart failure with preserved ejection fraction; Right atrium; Speckle-tracking; Strain imaging.