TY - JOUR T1 - Response to exercise in patients with pulmonary arterial hypertension treated with combination therapy JF - ERJ Open Research JO - erjor DO - 10.1183/23120541.00725-2020 SP - 00725-2020 AU - Mari Nishizaki AU - Aiko Ogawa AU - Hiromi Matsubara Y1 - 2020/01/01 UR - http://openres.ersjournals.com/content/early/2020/10/22/23120541.00725-2020.abstract N2 - Pulmonary arterial hypertension (PAH) -specific combination therapy improves pulmonary haemodynamics at rest in patients with PAH; nevertheless, exertional dyspnoea remains. We investigated pulmonary haemodynamic response to exercise, and the relation to ventilatory efficiency and hypoxemia in patients with PAH treated with combination therapy. Thirty-two clinically stable patients with PAH undergoing combination therapy underwent cardiopulmonary exercise testing with right-heart catheterisation. Haemodynamic impairment was moderate-to-severe before treatment. However, it was significantly improved, and in 13 patients after treatment, the mean pulmonary arterial pressure (mPAP) at rest was <25 mmHg. The mPAP significantly increased from 27.9±10.7 to 45.9±16.7 mmHg (p<0.01) during exercise. The cardiac index increased inadequately, and the total pulmonary resistance (TPR) significantly increased from 5.74±3.42 to 6.58±3.82 Wood units (p<0.01). The mPAP/cardiac output (CO) slope was steep (10.0±6.7 mmHg·L−1·min−1). It significantly correlated with both the minute ventilation/carbon dioxide output slope (r=0.51, p<0.01) and peripheral arterial oxygen saturation/workload slope (r=−0.41, p=0.02). The mPAP/CO slope also significantly correlated with mPAP at rest (r=0.73, p<0.01) and TPR at rest (r=0.64, p<0.01). Even after pulmonary haemodynamics at rest was significantly improved in PAH patients with PAH-specific combination therapy, the mPAP/CO slope was steep and the steep mPAP/CO slope related to decreased ventilatory efficiency and the severity of hypoxemia. The mPAP/CO slope was steeper in patients with higher mPAP and TPR at rest.FootnotesThis manuscript has recently been accepted for publication in the ERJ Open Research. It is published here in its accepted form prior to copyediting and typesetting by our production team. After these production processes are complete and the authors have approved the resulting proofs, the article will move to the latest issue of the ERJOR online. Please open or download the PDF to view this article.Conflict of interest: Dr. Nishizaki reports personal fees from Actelion Pharmaceuticals Japan Ltd., personal fees from Mochida Pharmaceutical Co., Ltd., personal fees from Nippon Shinyaku Co., Ltd., personal fees from Pfizer Japan Inc., personal fees from Sawai Pharmaceutical Co., Ltd., outside the submitted work.Conflict of interest: Dr. Ogawa reports personal fees from Actelion Pharmaceuticals Japan Ltd., personal fees from Pfizer Japan Inc., personal fees from Nippon Shinyaku Co., Ltd., outside the submitted work.Conflict of interest: Dr. Matsubara reports personal fees from Actelion Pharmaceuticals Japan Ltd., personal fees from AOP Orphan Pharmaceuticals AG, personal fees from Bayer Yakuhin, Ltd, personal fees from GlaxoSmithKline K.K., personal fees from Pfizer Japan Inc., personal fees from United Therapeutics Corporation, personal fees from Nippon Shinyaku Co., Ltd., personal fees from Kaneka Medix Corporation, outside the submitted work. ER -