Right Atrial Phasic Function in Heart Failure With Preserved and Reduced Ejection Fraction

Abstract

Objectives: This study researched right atrial (RA) deformation indexes and their association with all-cause mortality among subjects with or without heart failure (HF).

Background: Although left atrial dysfunction is well described in HF, patterns of RA dysfunction and their prognostic implications are unclear. Cardiac magnetic resonance (CMR) imaging can provide excellent visualization of the RA. We used CMR to characterize RA phasic function in HF and to assess its prognostic implications.

Methods: This study prospectively examined 608 adults without HF (n = 407), as well as adults with HF with a reduced ejection fraction (HFrEF) (n = 105) or with HF with a preserved ejection fraction (HFpEF) (n = 96). Phasic RA function was measured via volume measurements and feature-tracking methods to derive longitudinal strain. All-cause death was ascertained over a median follow-up of 38.9 months. Standardized hazard ratios (HRs) were computed via Cox regression.

Results: Measures of RA phasic function were more prominently impaired in subjects with HFrEF than those in subjects with HFpEF. In analyses that adjusted for demographic factors, HF status, left ventricular ejection fraction, right ventricular end-diastolic volume index, and right ventricular ejection fraction, RA reservoir strain (HR: 0.66; 95% confidence interval [CI]: 0.47 to 0.92; p = 0.0154), RA expansion index (HR: 0.53; 95% CI: 0.31 to 0.91; p = 0.0116), RA conduit strain (HR: 0.58; 95% CI: 0.40 to 0.84; p = 0.0039), and RA conduit strain rate (HR: 1.51; 95% CI: 1.02 to 2.220; p = 0.0373) independently predicted all-cause mortality. In contrast, RA booster pump function and RA volume index did not independently predict the risk of death.

Conclusions: Phasic RA function is predictive of the risk of all-cause death in a diverse group of subjects with and without HF. RA conduit and reservoir function are independent predictors of mortality.

Keywords: feature tracking; longitudinal strain; magnetic resonance imaging; right atrium.