Exercise intolerance in comorbid COPD and heart failure: the role of impaired aerobic function

Abstract

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 change in oxygen uptake (ΔV′O2)/change in work rate (ΔWR) 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 subset of patients (n=18).27 patients presented with ΔV′O2/ΔWR below the lower limit of normal. Despite similar forced expiratory volume in 1 s and ejection fraction, the low ΔV′O2/ΔWR group showed higher end-diastolic volume, lower inspiratory capacity and lower transfer factor compared to their counterparts (p<0.05). Peak WR and peakV′O2were ∼15% and ∼30% lower, respectively, 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 ΔV′O2/ΔWR group presented with other evidences of impaired aerobic function (sluggishV′O2kinetics, earlier anaerobic threshold) and cardiocirculatory performance (lower oxygen pulse, lower stroke volume and cardiac output) (p<0.05). Despite similar exertional hypoxaemia, 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 to improve oxygen delivery to and/or utilisation by the peripheral muscles might prove particularly beneficial to these patients.

The Value of Cardiopulmonary Exercise Testing in Determining Severity in Patients with both Systolic Heart Failure and COPD

“…In HF, the enlargement of the heart, venous congestion, and interstitial fibrosis compresses the lungs, leading to a restrictive pulmonary disorder 26 . The coexistence of diseases may lead to further increases in disability and mortality, perhaps even impairing the CPET results since variables of the test are poorer in these patients [17][18][19][20][21][22][23][24][25][26][27] .…”

Cardiorespiratory Coupling is Associated With Exercise Capacity in Patients With Chronic Obstructive Pulmonary Disease 

“…In terms of patients with heart failure, several comorbid conditions, such as skeletal muscle dysfunction, impaired autonomic regulation, and nutritional factors, may coexist and contribute to exercise intolerance [38]. Furthermore, impaired aerobic function due to negative cardiopulmonary muscular interaction contributes to low exercise intolerance in patients with COPD and in those suffering from heart failure [39]. In this study, there is no HFmrEF patient.…”

The Medusa faces of dyspnoea in COPD

“…Such assessment of the integrated cardiopulmonary response to exercise remains largely underutilised in the personalised assessment and management of patients with exercise limitation and breathlessness.The collaboration of two expert teams on exercise pathophysiology has extended our understanding considerably of this disabling problem, through a set of studies on exercise limitation in COPD patients and those with COPD and heart failure overlap. Their report is published in this issue of the European Respiratory Journal [4].…”

“…The collaboration of two expert teams on exercise pathophysiology has extended our understanding considerably of this disabling problem, through a set of studies on exercise limitation in COPD patients and those with COPD and heart failure overlap. Their report is published in this issue of the European Respiratory Journal [4].…”

“…ROCHA et al [4] report that impaired aerobic function, as primarily indicated by a low ΔV′CO 2 /Δwork rate during incremental CPET, discriminates a subgroup of patients with COPD-heart failure who are particularly symptomatic and disabled. This impaired aerobic function was associated with lower limits for tidal volume expansion, impaired gas exchange efficiency and a higher left ventricular end-diastolic diameter at rest, excessive exertional ventilation relative to the metabolic demand, higher operating lung volumes leading to earlier attainment of critical inspiratory constraints and a severely impaired peak aerobic capacity.…”