Characteristics of Patients Meeting the New Definition of Pre-capillary Pulmonary Hypertension (Nice 2018) in a Single Japanese Pulmonary Hypertension Center
Abstract Background: The 6th World Symposium on Pulmonary Hypertension (Nice 2018) proposed a new definition of pre-capillary pulmonary hypertension (PH) as a condition with mean pulmonary artery pressure (mPAP) > 20 mmHg, pulmonary artery wedge pressure (PAWP) ≤ 15 mmHg, and pulmonary vascular resistance (PVR) ≥ 3 Wood units (WU). The characteristics and prognosis of patients with pre-capillary PH, according to this new definition, is unclear. Therefore, we determined the characteristics of patients with pre-capillary PH who had pulmonary vascular disease with slight elevation in mPAP.Methods: We retrospectively enrolled 683 patients who underwent their first right heart catheterization (RHC) at Chiba University, Japan. Among them, 489 patients met the pre-capillary PH requirement with mPAP ≥ 25 mmHg (conventional pre-capillary PH group), while 22 patients met the borderline pre-capillary PH criteria (borderline pre-capillary PH group). Results: The borderline pre-capillary PH group comprised 4.3% of the total pre-capillary PH patients, and the majority was in Group 3 (40.9%) or 4 (45.5%). The survival of the borderline pre-capillary PH group tended to be better than that of the conventional pre-capillary PH group. Conclusions: Pre-capillary PH patients, according to the Nice 2018 definition, comprised 4.3 % of the population with total pre-capillary PH and had better survival than the conventional PH pre-capillary group; moreover, the majority of the pre-capillary PH cases were either Group 3 and 4.