Jiang R; Liu H; Pudasaini B; Zhang R; Xu JL; Wang L; Zhao QH; Yuan P; Guo
J; He J; Gong SG; Wu C; Wu WH; Luo CJ; Qiu HL; Jing ZC; Liu JM.

The clinical respiratory journal. 13(3):148-158, 2019 Mar. VI 1

BACKGROUND: Pulmonary hypertension patients with mean pulmonary artery
pressure (mPAP) >= 25 mm Hg had impaired cardiopulmonary exercise testing
(CPET). Borderline mean pulmonary pressures (boPAP; 21-24 mm Hg) represent
early pulmonary vasculopathy. The CPET characteristics of boPAP are a
matter of discussion. We aimed to determine the CPET profile of such
borderline hemodynamics.

METHODS: A matched case-control study was conducted on consecutive boPAP
patients at the Shanghai Pulmonary Hospital between Jan 2012 and Jan 2017.
Hemodynamics, echocardiography, the pulmonary function test (PFT) and CPET
parameters were compared between boPAP patients and normal mPAP patients
which were matched 1:1 by sex and age. Conditional logistic regression
analysis was performed to determine the efficacy of CPET in detecting
boPAP.

RESULTS: A total of 48 patients underwent RHC and CPET (24 Normal, 24
boPAP). There were no differences in the demographics, echocardiography
and PFT. BoPAP patients had significantly decreased VO2 at the anaerobic
threshold and peak VO2 /kg (858.4 +/- 246.5 mL/min vs 727.9 +/- 228.0
mL/min, P = 0.037; 21.1 +/- 6.4 mL/min/kg vs. 15.5 +/- 5.6 mL/min/kg, P =
0.001, respectively). Significant differences were not observed in
ventilation efficiency. A trend of impaired oxygen pulse and submaximal
exercise tolerance were observed in boPAP patients. Conditional logistical
regression analysis revealed the risk of boPAP increased by 2.493 (95%
confident interval: 1.388 to 4.476, P = 0.002) with every 5 mL/min/kg
decrease in peak VO2 /kg.

CONCLUSIONS: Patients with boPAP have a greater prevalence of exercise
intolerance, a trend of impaired oxygen pulse and submaximal exercise
tolerance.