Sotatercept on Central Cardiopulmonary Performance and Peripheral Oxygen Transport During Exercise in Pulmonary Arterial Hypertension

Inclusion Criteria * Informed consent obtained before any trial-related activities. Trial-related activities are any procedures that are carried out as part of the trial, including activities to determine suitability for the trial. * NYHA Class II-IV. * LVEF ≥ 40 % within the preceding year. * No recent initiation of pulmonary vasodilator in the last 60 days. * Pulmonary arterial hypertension by right heart catheterization (Mean PA pressure ≥ 20 mmHg with PVR\>2 Wood units) with no evidence of heart failure with preserved ejection fraction (exercise PCWP \<25 mm Hg). * Symptomatic PAH patients with plan to undergo exercise RHC for reassessment of exertional symptoms. Exclusion Criteria * Myocardial infarction, stroke, hospitalization for heart failure, unstable angina pectoris or transient ischemic attack within 30 days prior to the day of screening. * Planned coronary, carotid, or peripheral artery revascularization. * Any other condition judged by the investigator to be the primary cause of dyspnea (such as heart failure due to restrictive cardiomyopathy or infiltrative conditions (e.g., amyloidosis), hypertrophic obstructive cardiomyopathy, anemia, or more than moderate mitral or aortic heart valve disease). * Wheelchair bound or orthopedic inability to exercise. * Chronic hypoxemia with inability to exercise without oxygen supplementation. * Skeletal muscle myopathy. * History of rhabdomyolysis. * Participation in any clinical trial of an approved or non-approved devic…