Diagnosis and Management of Pulmonary Arterial Hypertension

Essential Diagnostic Criteria

The American College of Cardiology recommends that all patients suspected of having pulmonary arterial hypertension (PAH) after noninvasive evaluation must undergo right heart catheterization (RHC) prior to initiation of therapy, as echocardiography alone is insufficient to confirm a diagnosis of PAH and initiate treatment 2
The European Respiratory Society suggests that RHC is required to definitively establish PAH by documenting a mean pulmonary artery pressure (mPAP) ≥25 mmHg at rest, pulmonary capillary wedge pressure (PCWP) ≤15 mmHg, and pulmonary vascular resistance (PVR) >3 Wood units 2, 3, 6

The American College of Cardiology states that the PVR measurement is crucial because it distinguishes passive PH (elevated mPAP with normal PVR) from PH caused by pulmonary vascular disease (elevated mPAP with elevated PVR) 2
The European Respiratory Society recommends that the transpulmonary gradient (PAP mean - wedge pressure) must be assessed to identify intrinsic pulmonary vascular changes versus passive increases from left heart dysfunction 6

The American College of Cardiology suggests that ventilation-perfusion (V/Q) scan should be completed to exclude chronic thromboembolic pulmonary hypertension (CTEPH), with sensitivity >90% and specificity >94% 3
The European Respiratory Society recommends that pulmonary function tests with DLCO should be assessed to evaluate for underlying obstructive or restrictive lung disease 3

The American College of Cardiology states that the hemodynamic profile obtained from RHC provides critical prognostic information and guides treatment decisions, including vasoreactivity testing which determines eligibility for calcium channel blocker therapy 2