Association between right heart size and right ventricular output reserve in patients with pulmonary arterial hypertension

Objectives: Right ventricular (RV) output reserve, defined as increase of cardiac output during exercise is reduced in patients with pulmonary arterial hypertension (PAH). Aim of this study was to evaluate the association of right heart size measured by echocardiography and invasively measured RV function at rest and during exercise in PAH patients.

Methods: Adult PAH patients who received routine hemodynamic assessment at rest and during exercise with echocardiographic measurement of right heart size (right atrial (RA) and right ventricular (RV) area) were included in this study. Clinical, echocardiographic, laboratory, exercise and hemodynamic parameters were retrospectively analysed. The primary endpoint was the association between right heart size and right ventricular pump function.

Results: Data from 215 PAH (age 58.9± 15.9 years, 63.3% female, 62.2% double or triple combination treatment) patients were analysed in this cross-sectional study. RA and RV area correlated with TAPSE/sPAP (both p<0.001, R -0.570 and -0.530). Patients with RA area>18 cm2 or RV area>20 cm2 were significantly taller, heavier and presented with more impaired hemodynamics (pulmonary vascular resistance p<0.001). Cardiac index was significantly lower for patients with RA area>18 cm2 at rest, 25 and 50 Watts (all p<0.001) and for patients with RV area>20 cm2 at rest, 25, 50 and 75 Watts (all p<0.001). Furthermore, pulmonary arterial compliance (all p<0.05) and mPAP/CO slope (all p<0.001) significantly differed between groups for both RA and RV area.

Conclusion: This study could confirm that an enlargement of RA and RV area is associated with an impaired RV function at rest and during exercise in patients with PAH.

Publication History

Article published online:
01 March 2024