In CTEPH, the RHC has additional importance, as pulmonary vascular resistance is the most important determinant of prognosis and the risk associated with pulmonary endarterectomy (PTE) (also called pulmonary endarterectomy [PEA])1
CTEPH is defined as precapillary PH as assessed by RHC (mean pulmonary arterial pressure [PAP] ≥25 mm Hg, pulmonary capillary wedge pressure [PCWP] ≤15 mm Hg) in the presence of multiple chronic/organized occlusive thrombi/emboli in the elastic pulmonary arteries (main, lobar, segmental, subsegmental) after at least 3 months of effective anticoagulation 2
1. Jenkins D, Mayer E, Screaton N, Madani M. State-of-the-art chronic thromboembolic pulmonary hypertension diagnosis and management. Eur Respir Rev. 2012;21(123):32-39. 2. Wilkens H, Lang I, Behr J, et al. Chronic thromboembolic pulmonary hypertension (CTEPH): updated recommendations of the Cologne Consensus Conference 2011. Int J Cardiol. 2011;154(Suppl 1):S54-S60. 3. Mathier M. The nuts and bolts of interpreting hemodynamics in pulmonary hypertension associated with diastolic heart failure. Advances in PH. 2011;10(1):33-40.