Pulmonary Arterial Hypertension (PAH) (WHO Group 1 PH)

This study evaluates the effects of VI-0106 (an extended-release formulation of tacrolimus) in participants with pulmonary arterial hypertension (PAH) who continue to have functional limitations despite being on optimized background PAH therapy. Participants will be randomly assigned with equal chance to receive either VI-0106 or placebo in a double-blind fashion to assess whether VI-0106 improves outcomes in this population.

This methodological study aims to develop and validate a questionnaire named for the Assessment of Patient Knowledge in Pulmonary Arterial Hypertension. The study will be conducted in four phases: (1) questionnaire development based on guidelines and literature; (2) content validation by expert judges; (3) semantic validation with patients; and (4) psychometric testing in a sample of up to 200 patients with confirmed pulmonary arterial hypertension (PAH). In addition to validation, the study will collect clinical and functional data from medical records, including risk stratification using the COMPERA 2.0 method The final instrument is expected to support patient education strategies and contribute to improved clinical management of PAH.

The goal of this observational study is to learn more about how genes impact the risk of pulmonary hypertension. Anyone 18 or older living in the US is eligible, and a diagnosis of PH is NOT required. Study participation is online, and it takes about 20 minutes to complete health surveys and request a saliva collection kit sent through US mail. In return, study participants may opt to receive information about their genetic ancestry at no cost.

Pulmonary arterial hypertension (PAH) is a rare, progressive, and potentially fatal disease characterized by increased pulmonary vascular resistance and right ventricular dysfunction. Among the four major molecular pathways involved in PAH pathophysiology-nitric oxide, prostacyclin, activin, and endothelin-1 (ET-1)-the endothelin pathway plays a central role. Endothelin-1 acts on ETA and ETB receptors, inducing vasoconstriction and vascular remodeling. Endothelin receptor antagonists (ERAs) are cornerstone therapies in PAH. Ambrisentan is selective for ETA and associated with a lower risk of hepatotoxicity. Bosentan, a dual ERA (ETA/ETB), has well-established efficacy but a higher incidence of liver enzyme elevation, with approximately 9% of patients experiencing hepatic side effects and about 2% discontinuing therapy due to hepatotoxicity. While transitions between ERAs occur in routine clinical practice, data on their clinical impact are scarce. This prospective, observational, single-center cohort study aims to evaluate the effect of switching from ambrisentan to bosentan on risk stratification using the COMPERA 2.0 and REVEAL Lite 2.0 scores at 3-6 months post-switch. Secondary outcomes include variations in functional class (WHO/NYHA), 6-minute walk distance (6MWD), NT-proBNP levels, incidence of adverse events (with a focus on hepatotoxicity), and hematologic parameters such as anemia. The study will enroll adult patients (≥18 years) with confirmed PAH by right heart catheterization who have undergone a documented switch from ambrisentan 10 mg to bosentan 125 mg within the last 6 months. The primary endpoint is the proportion of patients whose risk category changes post-transition according to COMPERA 2.0 and REVEAL Lite 2.0. The results are expected to provide clinically relevant insights into therapeutic decisions involving ERA transitions in PAH management.

Understanding Delays in the Diagnosis of Pulmonary Arterial Hypertension and Rare Diseases in Brazil: A Multicenter Observational Study \--- Pulmonary arterial hypertension (PAH) is a rare, progressive, and life-threatening disease that affects the arteries of the lungs and the right side of the heart. Early diagnosis is essential to initiate appropriate treatment and improve patient outcomes. However, worldwide studies show that there is often a significant delay between the onset of symptoms and the final diagnosis. This delay may lead to disease progression and worse survival. This multicenter observational study aims to understand the time from the first symptoms to the diagnosis of PAH and other rare diseases across several Brazilian reference centers. By analyzing medical records and patient journeys, the investigators intends to identify factors contributing to delayed diagnosis and potential opportunities for earlier detection. The study includes adult patients diagnosed with PAH or other selected rare diseases within the last five years. The investigators will analyze time to diagnosis, number and type of physicians consulted, tests performed, and possible misdiagnoses. Our goal is to support the development of strategies that reduce diagnostic delay and improve access to specialized care for people living with rare diseases. This study does not involve any intervention and poses no additional risk to participants, as it is based solely on retrospective data from medical records.

Pulmonary arterial hypertension (PAH) is a progressive condition with high morbidity, frequent hospitalizations, and risk of right heart failure. Despite advances in treatment, poor adherence remains a major challenge. This randomized controlled study assesses whether remote monitoring can improve treatment adherence, clinical outcomes, and side effect management in PAH patients on oral therapy.