Hemodynamic Definition of Pulmonary Hypertension: Commentary on the Proposed Change by the 6th World Symposium on Pulmonary Hypertension

The ESC/ERS guidelines (published at the end of 2015) and other international recommendations defined pulmonary hypertension (PH) by an invasively measured mean pulmonary arterial pressure (mPAP) ≥ 25 mmHg at rest. At the 6th World Symposium on Pulmonary Hypertension in Nice a modification of this hemodynamic definition in the sense of lowering the threshold to > 20 mmHg was proposed. A pulmonary vascular resistance (PVR) ≥ 3 Wood units (WU) is additionally required for the diagnosis of pre-capillary PH. This modification must be critically reviewed with regard to the underlying rationale and possible consequences. Therefore, a detailed explanation is required. In particular, it must be made clear that this change currently has no influence on the evidence-based and approval-compliant prescription of drugs for the targeted therapy of pulmonary arterial hypertension (PAH).