Insights From the Fifth World Health Organization Symposium Working Group: Definitions and Diagnosis of Pulmonary Hypertension

Fernando Torres, MD Head of the Lung Transplant and Pulmonary Hypertension Programs UT Southwestern Medical Center Dallas, TX During the Fifth World Symposium on Pulmonary Hypertension, the working group on diagnosis and assessment was charged with evaluating the definition of pulmonary arterial hypertension (PAH) as it was established at the Fourth World Symposium. The group also covered related topics such as “borderline PAH,” exercise-induced PAH, and issues surrounding the measurement of pulmonary capillary wedge pressure (PCWP). The working group’s discussion specifically addressed the following questions: 1. Should pulmonary hypertension (PH) continue to be defined by a resting mean pulmonary artery pressure (MPAP) 25 mm Hg, and should the term “borderline PH” be introduced? 2. Should exercise-induced PH be included as a subset of PH? 3. Should pulmonary vascular resistance (PVR) be reintroduced in the definition of PAH? 4. Is pulmonary artery wedge pressure (PAWP) of 15 mm Hg adequate to distinguish between preand post-capillary PH, and how should it be measured? 5. Should fluid or exercise challenge be used to distinguish patients with PAH from pulmonary venous hypertension (PVH)? 6. Should exercise hemodynamics be used to unmask left sided heart failure?