Resting right ventricular function is associated with exercise performance in PAH, but not in CTEPH.

Area of Science:

• Cardiology
• Pulmonology
• Echocardiography

Background:

• Pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH) are severe conditions affecting the right ventricle (RV).
• Assessing RV function is crucial for understanding disease severity and prognosis in these patients.
• Exercise performance is a key indicator of functional capacity and outcomes.

Purpose of the Study:

• To investigate the association between resting right ventricular (RV) function and exercise performance in patients with PAH and CTEPH.
• To determine if RV longitudinal strain (RVLS) and RV fractional area change (FAC) can predict exercise capacity in these patient groups.

Main Methods:

• Prospective recruitment of 46 PAH and 42 CTEPH patients undergoing cardio-pulmonary exercise testing (CPET) and echocardiography.
• Resting RV systolic function assessed using RVLS and FAC.
• CPET parameters included percentage of predicted maximal oxygen consumption (VO2max) and VE/VCO2 slope; Spearman correlation analyzed associations.

Main Results:

• In PAH, RVLS and FAC were significantly associated with VE/VCO2 and percentage predicted VO2max.
• In contrast, no significant association was found between resting RV function (RVLS or FAC) and exercise parameters in CTEPH patients.
• This suggests a disconnect between RV function and exercise capacity in CTEPH.

Conclusions:

• Resting RV function, assessed by FAC and RVLS, is linked to exercise performance in PAH, offering a potential non-invasive assessment tool.
• The lack of association in CTEPH indicates that resting RV function may not be a reliable predictor of exercise performance, impacting its use as a prognostic marker.