Exercise hemodynamics in heart failure patients with preserved and mid-range ejection fraction: key role of the right heart.

OBJECTIVE: We sought to explore whether classification of patients with heart failure and mid-range (HFmrEF) or preserved ejection fraction (HFpEF) according to their left ventricular ejection fraction (LVEF) identifies differences in their exercise hemodynamic profile, and whether classification according to an index of right ventricular (RV) function improves differentiation. BACKGROUND: Patients with HFmrEF and HFpEF have hemodynamic compromise on exertion. The classification according to LVEF implies a key role of the left ventricle. However, RV involvement in exercise limitation is increasingly recognized. The tricuspid annular plane systolic excursion/systolic pulmonary arterial pressure (TAPSE/PASP) ratio is an index of RV and pulmonary vascular function. Whether exercise hemodynamics differ more between HFmrEF and HFpEF than between TAPSE/PASP tertiles is unknown. METHODS: We analyzed 166 patients with HFpEF (LVEF ≥ 50%) or HFmrEF (LVEF 40-49%) who underwent basic diagnostics (laboratory testing, echocardiography at rest, and cardiopulmonary exercise testing [CPET]) and exercise with right heart catheterization. Hemodynamics were compared according to echocardiographic left ventricular or RV function. RESULTS: Exercise hemodynamics (e.g. pulmonary arterial wedge pressure/cardiac output [CO] slope, CO increase during exercise, and maximum total pulmonary resistance) showed no difference between HFpEF and HFmrEF, but significantly differed across TAPSE/PASP tertiles and were associated with CPET results. N-terminal pro-brain natriuretic peptide concentration also differed significantly across TAPSE/PASP tertiles but not between HFpEF and HFmrEF. CONCLUSION: In patients with HFpEF or HFmrEF, TAPSE/PASP emerged as a more appropriate stratification parameter than LVEF to predict clinically relevant impairment of exercise hemodynamics. Stratification of exercise hemodynamics in patients with HFpEF or HFmrEF according to LVEF or TAPSE/PASP, showing significant distinctions only with the RV-based strategy. All data are shown as median [upper limit of interquartile range] and were calculated using the independent-samples Mann-Whitney U test or Kruskal-Wallis test. PVR pulmonary vascular resistance; max maximum level during exercise.