Sequential analysis of right ventricular function and exercise capacity in pulmonary arterial hypertension

Abstract

Background: Emerging right ventriculopulmonary arterial (RV–PA) coupling and right ventricular (RV) diastolic function indices have been recently introduced. However, little is known about their clinical relevance in medically treated pulmonary arterial hypertension (PAH) patients. Aims: To examine the changes in RV–PA coupling and RV diastolic function indices in PAH patients on medical treatment and the association of these indices with 6-minute walk distance (6MWD). Method: We studied 27 PAH patients with intensified use of PAH-approved drugs and calculated RV–PA coupling [pressure method-derived index, Ees/Ea (P), and volume method-derived index, Ees/Ea (V)] and RV diastolic function (end-diastolic elastance, Eed) indices before and after treatment intensification. Associations among changes in RV indices, other PAH-related parameters, and 6MWD were analyzed. Patients were classified into two groups according to the improvement in 6MWD (≥10% or Results: During a follow-up of 12 (4–19) months, Ees/Ea (V) increased from 0.76 (median) to 0.92 (p = 0.015) and Eed decreased from 0.25 to 0.17 mmHg/mL (p = 0.017). 6MWD increased from 365 m to 390 m (n = 21, p = 0.024). The changes in Ees/Ea (P) and Eed were significantly correlated with the change in 6MWD (ρ = 0.47, ρ = −0.44). Eed decreased more in the group with greater improvement in 6MWD (≥10%) than in the other group (p Conclusion: Intensified use of PAH-approved drugs improves RV–PA coupling and RV diastolic function, which may ameliorate exercise capacity in PAH.