Exercise Capacity and Right Atrial Impairment in HF With Preserved Ejection Fraction

Among patients with heart failure with preserved ejection fraction (HFpEF), the gravity of the restrictions in booster pump function and right atrial reservoir during exercise are associated with reduced capability for exercise, meager cardiac output, and right ventricular (RV) systolic reserve. These findings were published in the Journal of the American Society of Echocardiography.

While multiple restrictions exist for patients with HFpEF during exercise, there remains a paucity of data for right atrial (RA) reserve capacity in these patients. Researchers sought to determine the association and diagnostic value of RA impairments with exercise capacity and right ventricular function in patients with HFpEF.

To accomplish this, they conducted a retrospective study of 197 patients (89 patients with HFpEF, and a control cohort of 108 patients without HF) who participated in echocardiography during bicycle exercise. Sizes of left ventricular (LV) and RV were similar between cohorts, and, sex, body mass index (BMI), and comorbidities were also comparable between cohorts. Patients in the test cohort were older and more likely to have heart disease, hypertension, and diabetes.

Measurements at rest and during exercise were taken for RA reservoir, conduit, and booster pump strain. RA conduit and booster pump strain were comparable in the 2 cohorts at rest, however, for the test cohort, RA reservoir strain was lower than for the control cohort (27.0±17.1 vs 38.6±17.1 %; P <.0001). Researchers noted, “despite the similar RV and RA size, patients with HFpEF had lower RA reservoir strain at rest than control subjects while RA booster pump strain was similar between groups.”

RA reservoir and booster pump function showed significant limitations for the test cohort compared to controls during peak exercise, and were correlated with RV systolic function. After adjusting for confounding factors like BMI, age, and coronary artery disease, the differences were still significant. There was also a weak association between lower RA booster pump strain during exercise and lower cardiac output (r=0.34; P <.0001) and reduced peak VO₂ (r=0.47; P <.0001).

Study limitations included that there were some HFpEF patients that may have been inadvertently excluded and some control patients may have had atrial fibrillation. The RA strain was also unmeasurable in 13% of patients. The researchers used apical 4-chamber views instead of apical 2-chamber views and used speckle tracking echocardiography instead of real-time cardiac magnetic resonance imaging. There were also some patients with tricuspid valve disease or non-Group II pulmonary atrial hypertension with impaired RA strain at rest and during exercise.

Researchers concluded, “Compared to control subjects, patients with HFpEF have limitations to augment RA reservoir and booster pump function during exercise, and these abnormalities are associated with lower cardiac output, more severe RV dysfunction, and poorer aerobic capacity.”

Reference

Kagami K, Harada T, Yoshida K, et al. Impaired right atrial reserve function in heart failure with preserved ejection fraction. J Am Soc Echocardiogr. Published online March 10, 2022. doi:10.1016/j.echo.2022.03.006