Association of pulmonary hypertension and right ventricular function with exercise capacity in heart failure

Relationships of pulmonary artery systolic pressure (PASP) and right ventricular (RV) dysfunction with exercise capacity are understudied. To assess the relationship of PASP and RV function with functional capacity and ventilatory efficiency in heart failure (HF) with a wide range of left ventricular ejection fraction (LVEF).

Five hundred thirty-two consecutive HF patients referred for cardiopulmonary exercise testing [percent predicted peak VO₂ (ppVO₂ ), V_E /V_CO2 slope] and echocardiography [LVEF, PASP, and RV fractional area change (RVFAC)] were studied. Associations of PASP and RVFAC with ppVO₂ and V_E /V_CO2 slope were assessed by multivariable linear regression and restricted cubic splines. Associations with composite of death, heart transplant, and LV assist device (median 3.9 year follow-up) was assessed using multivariable Cox proportional hazard models. Mean age was 56 ± 14 years and mean LVEF was 35 ± 15%. Mean PASP was 34 ± 12 mmHg, RVFAC was 41 ± 13%, ppVO₂ was 60 ± 21%, and V_E /V_CO2 slope was 35 ± 12. After adjusting for demographics, co-morbidities, LVEF, mitral regurgitation severity, and left atrial volume index, higher PASP was associated with worse ppVO₂ (P = 0.004) and was more robust in patients with LVEF ≥45% vs. <45% (P_interaction  = 0.006). Lower RVFAC was associated with both worse ppVO₂ (P = 0.002) and higher V_E /V_CO2 slope (P = 0.002). Higher PASP and lower RVFAC were both associated with heightened risk of composite endpoint (HR 1.07 per 5 mmHg increase, P = 0.03; HR 1.17 per 5% decrease, P <0.001, respectively).

In HF across wide range of LVEF, greater PASP and worse RV function predict worse functional capacity and greater respiratory inefficiency, independent of LV structure and function.