The investigators are testing whether the addition of Pulmonary Hypertension-related biomarkers, measured across the pulmonary circulation, to the standard hemodynamic evaluation for Pulmonary Hypertension will lead to more informed choices of Pulmonary Hypertension therapy and improved patient outcomes.

Eligible participants with known or suspected Pulmonary Hypertension undergoing a clinically indicated right heart catheterization may be enrolled. Clinical data and blood samples will be analyzed.

Inclusion Criteria:

• Age ≥ 18 years old
• Undergoing RHC for PH evaluation

Exclusion Criteria:

• Anemia defined as Hgb < 10 g/dL and HCT < 30
• Pregnancy at the time of RHC (as assessed by urine or serum pregnancy test on the day of the procedure)
• Left ventricular ejection fraction ≤ 40%
• Atrial fibrillation at the time of RHC (as defined by telemetry monitoring or EKG on the day of the procedure)
• IPF, CTEPH, COPD/OSA as the dominant etiology of PH
• Patient is currently taking PH medication or long-acting nitrates at the time of their RHC.

Pulmonary Vascular Clinic