Flolan

The goal of this clinical trial is to determine whether sotatercept is effective in improving diffusing capacity in patients with pulmonary arterial hypertension. Participants will be asked to: * Take Sotatercept every 21 days (±3 days) * Each participant will be enrolled in the study for 29 Weeks * Visit the clinic 18 times * Have a physical exam * Perform assessments of lung function and exercise tests * Have an ultrasound of their heart * Have blood draws done at regular intervals The main objectives of the study are: Primary objective: To assess whether sotatercept will improve recruitment of diffusing membrane capacity (DM) with exercise. Secondary objective: To identify components of the diffusing capacity that respond to treatment with sotatercept in pulmonary arterial hypertension.

The purpose of this research is to gather information on the safety and effectiveness of a new procedure called Fetoscopic Endoluminal Tracheal Occlusion (FETO).

Many control mechanisms exist which successfully match the supply of blood with the metabolic demand of various tissues under wide-ranging conditions. One primary regulator of vasomotion and thus perfusion to the muscle tissue is the host of chemical factors originating from the vascular endothelium and the muscle tissue, which collectively sets the level of vascular tone. With advancing age and in many disease states, deleterious adaptations in the production and sensitivity of these vasodilator and vasoconstrictor substances may be observed, leading to a reduction in skeletal muscle blood flow and compromised perfusion to the muscle tissue. Adequate perfusion is particularly important during exercise to meet the increased metabolic demand of the exercising tissue, and thus any condition that reduces tissue perfusion may limit the capacity for physical activity. As it is now well established that regular physical activity is a key component in maintaining cardiovascular health with advancing age, there is a clear need for further studies in populations where vascular dysfunction is compromised, with the goal of identifying the mechanisms responsible for the dysfunction and exploring whether these maladaptations may be remediable. Thus, to better understand the etiology of these vascular adaptations in health and disease, the current proposal is designed to study changes in vascular function with advancing age, and also examine peripheral vascular changes in patients suffering from chronic obstructive pulmonary disease (COPD), Sepsis, Pulmonary Hypertension, and cardiovascular disease. While there are clearly a host of vasoactive substances which collectively act to govern vasoconstriction both at rest and during exercise, four specific pathways that may be implicated have been identified in these populations: Angiotensin-II (ANG-II), Endothelin-1 (ET-1), Nitric Oxide (NO), and oxidative stress.