Research to define the characteristics and prognosis of patients with pre-capillary pulmonary hypertension (PH) was recently published in BMC Pulmonary Medicine.
The 6th World Symposium on Pulmonary Hypertension (WSPH) in 2018 proposed a new definition for pre-capillary PH (mean pulmonary artery pressure >20 mm Hg; pulmonary artery wedge pressure ≤15 mm Hg; and pulmonary vascular resistance ≥3 Wood units), as well as treatment guidelines for 5 different groups of patients (group 1: pulmonary arterial hypertension; group 2: PH due to left heart disease; group 3: PH due to lung diseases or hypoxia; group 4: PH due to pulmonary artery obstructions; group 5: PH with unclear and/or multifactorial mechanisms).
Yet according to investigators for the current study, the 6th WSPH did not clearly define the characteristics and prognosis of patients with pre-capillary PH. To clarify this, researchers at a PH center at Chiba University, one of Japan’s high-volume pulmonary endarterectomy centers, conducted what they said is their region’s first study to reveal the characteristics of patients with pre-capillary PH as defined by the 6th WSPH.
The retrospective study included 683 patients who underwent their first right heart catheterization. Of these, 489 patients met the WSPH pre-capillary pulmonary hypertension criteria, and 22 patients met the borderline pre-capillary pulmonary hypertension criteria.
Only 4.3% of patients with pre-capillary PH met the criteria for being borderline. Of those, most met the WSPH criteria for group 3 (40.9%) or group 4 (45.5%). Additionally, survival rates in the borderline pre-capillary PH group tended to be better than that of the conventional pre-capillary pulmonary hypertension group.
Investigators concluded that “Prognosis may be affected by patients’ underlying diseases.” They added that further prospective studies are needed to determine whether the 2018 WSPH definition of pre-capillary PH, including the pulmonary vascular resistance cut-off, is beneficial in clinical practice, and whether the WSPH guidelines are valuable in identifying patients with PH who require prescription vasodilators.
Yamamoto, Keiko et al. “Characteristics of patients meeting the new definition of pre-capillary pulmonary hypertension (Nice 2018) in a single Japanese pulmonary hypertension center.” BMC pulmonary medicine vol. 21,1 260. 9 Aug. 2021, doi:10.1186/s12890-021-01623-2