PT - JOURNAL ARTICLE AU - Alcides Rocha AU - Flavio F. Arbex AU - Priscila A. Sperandio AU - Frederico Mancuso AU - Mathieu Marillier AU - Anne-Catherine Bernard AU - Maria Clara N. Alencar AU - Denis E. O. Donnell AU - J. Alberto Neder TI - Exercise intolerance in comorbid COPD-heart failure: the role of impaired aerobic function AID - 10.1183/13993003.02386-2018 DP - 2019 Jan 01 TA - European Respiratory Journal PG - 1802386 4099 - http://erj.ersjournals.com/content/early/2019/01/23/13993003.02386-2018.short 4100 - http://erj.ersjournals.com/content/early/2019/01/23/13993003.02386-2018.full AB - Impaired aerobic function is a potential mechanism of exercise intolerance in patients with combined cardiorespiratory disease. We investigated the pathophysiological and sensory consequences of a low Δ O2 uptake (V̇O2)/Δ work rate (WR) relationship during incremental exercise in patients with coexisting chronic obstructive pulmonary disease (COPD) and systolic heart failure (HF).After clinical stabilisation, 51 COPD-HF patients performed an incremental cardiopulmonary exercise test to symptom limitation. Cardiac output was non-invasively measured (impedance cardiography) in a sub-set of patients (N=18).Twenty-seven patients presented with Δ V̇O2/Δ WR below the lower limit of normal. Despite similar FEV1 and ejection fraction, the low Δ V̇O2/Δ WR group showed higher end-diastolic volume, lower inspiratory capacity and lower transfer factor compared to their counterparts (p<0.05). Peak WR and peak V̇O2 were ∼15% and ∼30% lower in the former group: those findings were associated with greater symptom burden in daily life and at a given exercise intensity (leg discomfort and dyspnoea). The low Δ V̇O2/Δ WR group presented with other evidences of impaired aerobic function (sluggish V̇O2 kinetics, earlier anaerobic threshold) and cardiocirculatory performance (lower O2 pulse, lower stroke volume and cardiac output) (p<0.05). Despite similar exertional hypoxemia, they showed worse ventilatory inefficiency and higher operating lung volumes which led to greater mechanical inspiratory constraints (p<0.05).Impaired aerobic function due to negative cardiopulmonary-muscular interactions is an important determinant of exercise intolerance in patients with COPD-HF. Treatment strategies able to improve O2 delivery to and/or utilisation by the peripheral muscles might prove particularly beneficial to these patients.FootnotesThis manuscript has recently been accepted for publication in the European Respiratory Journal. 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 ERJ online. Please open or download the PDF to view this article.Conflict of interest: Dr. ROCHA has nothing to disclose.Conflict of interest: Dr. ARBEX has nothing to disclose.Conflict of interest: Dr. SPERANDIO has nothing to disclose.Conflict of interest: Dr. MANCUSO has nothing to disclose.Conflict of interest: Dr. MARILLIER has nothing to disclose.Conflict of interest: Dr. BERNARD has nothing to disclose.Conflict of interest: Dr. ALENCAR has nothing to disclose.Conflict of interest: Dr. O'DONNELL has nothing to disclose.Conflict of interest: Dr. NEDER has nothing to disclose.