Fig. 1

Selection of patients. a Among 1542 cases of right heart catheterization (RHC) handled at the Chiba University, Japan, we enrolled 683 patients who underwent the first RHC. Among these, 531 patients had mPAP ≥ 25 mmHg (conventional PH group), and 50 patients had 25 > mPAP > 20 mmHg (borderline PH group). There were 102 patients with mPAP < 20 mmHg (non-PH group). PH, pulmonary hypertension; mPAP, mean pulmonary arterial pressure. b We chose patients with PH and pulmonary vascular disease, namely those with pre-capillary PH (mPAP > 20 mmHg with PAWP ≤ 15 mmHg and PVR ≥ 3 WU). Among the patients with pre-capillary PH (n = 501), 489 had mPAP ≥ 25 mmHg (conventional pre-capillary group) and 22 patients had 25 > mPAP > 20 mmHg (borderline pre-capillary group). PH, pulmonary hypertension; mPAP, mean pulmonary arterial pressure; PAWP, pulmonary arterial wedge pressure; PVR, pulmonary vascular resistance; WU, Wood units