Abstract 4143935: Clinical and Hemodynamic Correlates of Supranormal Ejection Fraction in Heart Failure with Preserved Ejection Fraction (HFpEF)

Introduction: Patients with heart failure with preserved ejection fraction (HFpEF) with EF≥65% may have a higher risk for adverse outcomes, however, the exercise, functional status, and hemodynamic correlates of this phenotype in a contemporary cohort is not well defined. Methods: This single-center study included patients with LVEF ≥50% with clinically indicated invasive right heart catheterization and echocardiogram enrolled in a prospective HFpEF registry at UT Southwestern between 4/2022-5/2024. Participants underwent peak oxygen uptake (VO 2 ) assessment with maximal bicycle test (Lode ergometer), quality of life assessment (Kansas City Cardiomyopathy Questionnaire [KCCQ]), physical function testing with the Short Physical Performance Battery (SPPB), and 6-minute walk distance (6MWD). Participants were stratified by those with EF ≥ 65% and EF 50%-65%. Multivariable adjusted linear regression models were used to evaluate the association of EF ≥ 65% with peak VO 2 , quality of life, noninvasive and invasive cardiac filling pressures, and functional outcomes. Results: 347 participants were included in the study. 112 (32.3%) participants had EF≥65%, and there were no differences in demographics across EF subgroups. Patients with EF≥65% had a higher burden of hypertension (94.6% vs. 86.8%, p = 0.04) and had higher E/e’ (14.0[95% CI 10.9-18.0] vs. 12.7[95% CI 9.5-16.7], p = 0.048) and PCWP with exercise (27[95% CI 20-30] vs 22[95% CI 18-28] mmHg, p=0.04) without differences in resting PCWP or PCWP/cardiac output slope at maximal exercise. After adjustment for age, sex, race, and BMI, EF≥65% was associated with higher KCCQ. However, these findings were attenuated after adjustment for comorbidities (Model 1: β 6.6, p=0.05 vs Model 2: β 6.0, p=0.08). EF≥65% was not associated with functional outcomes, peak exercise capacity, or elevated filling pressures in adjusted models. (Table) Conclusions: There were no significant differences in quality of life, functional status, exercise capacity, and filling pressures among patients with supranormal and normal ejection fraction. These findings suggest that extra-cardiac mechanisms may be more important contributors to functional status and peak exercise capacity in patients with EF≥65%.