Kevin Gain

Exercise Intolerance in Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is associated with symptoms of dyspnea and fatigue, which contribute to exercise limitation. The origins and significance of dyspnea and fatigue in PAH are not completely understood. This has created uncertainly among healthcare professionals regarding acceptable levels of these symptoms, on exertion, for patients with PAH. Dysfunction of the right ventricle (RV) contributes to functional limitation and mortality in PAH; however, the role of the RV in eliciting dyspnea and fatigue has not been thoroughly examined. This paper explores the contribution of the RV and systemic and peripheral abnormalities to exercise limitation and symptoms in PAH. Further, it explores the relationship between exercise abnormalities and symptoms, the utility of the cardiopulmonary exercise test in identifying RV dysfunction, and offers suggestions for further research.

Continuous positive airway pressure titration for obstructive sleep apnoea: automatic versus manual titration

Background and aims Manual laboratory continuous positive airway pressure (CPAP) titration for obstructive sleep apnoea (OSA) is costly, time intensive and delays access to treatment. Automatic positive airway pressure (APAP) titration has the potential to reduce cost and improve access to treatment. The aim of this study was to assess the clinical efficacy and costs of APAP titration compared with manual titration in moderate–severe OSA. Methods Patients with moderate–severe OSA (apnoea/hypopnoea index >15 and Epworth Sleepiness Score ≥8) who were free of co-morbidities that could impair APAP titration were eligible. 249 participants were randomised to manual titration, home APAP or laboratory APAP titration to determine a fixed pressure for CPAP. Clinical and direct cost outcomes were assessed after 4 weeks of treatment. Results Average nightly CPAP use, subjective sleepiness, SF36 quality of life, Trails A and B cognitive function and polysomnographic outcomes were similar among the per-protocol groups. Non-hypertensive patients had a lower resting heart rate (and greater reduction in heart rate) at 4 weeks after laboratory APAP titration compared with home APAP titration. Costs per patient were highest in manual (AU

Validation of the Cambridge Pulmonary Hypertension Outcome Review (CAMPHOR) for the Australian and New Zealand population

817.84), followed by laboratory (AU

Implications of exercise-induced pulmonary arterial hypertension

647.56) and home (AU

Psychometric performance of the CAMPHOR and SF-36 in pulmonary hypertension

132.09) APAP titration. An intention-to-treat analysis confirmed the effectiveness of APAP titration compared with manual titration in the standard clinical setting. Conclusions Among patients with moderate–severe OSA without serious co-morbidities, outcomes at 1 month indicate that APAP titration is more cost-effective than manual laboratory titration to determine an appropriate pressure for CPAP for long-term use; with the largest savings occurring in the home APAP patients. Australian New Zealand Clinical Trials Registry Number ACTRN12608000054314.

Short term effects of exercise training on exercise capacity and quality of life in patients with pulmonary arterial hypertension: protocol for a randomised controlled trial

Background and objective:  Individuals with pulmonary arterial hypertension (PAH) experience severely impaired quality of life. A disease‐specific patient reported outcome measure for PAH (the Cambridge Pulmonary Hypertension Outcome Review—CAMPHOR) has recently been developed and validated in the UK, USA and Canada. It has demonstrated reliability and validity in PAH populations in these countries. The aim of this study was to assess the reliability and validity of the CAMPHOR in an Australian and New Zealand (NZ) PAH population.

Impairments after curative intent treatment for non-small cell lung cancer: A comparison with age and gender-matched healthy controls

PURPOSE To characterize the hemodynamic and ventilatory responses to exercise in a group of patients with unexplained dyspnea, increased risk for pulmonary arterial hypertension (PAH), and an elevated mean pulmonary artery pressure (mPAP; >30 mm Hg) on exercise. METHODS A total of 37 symptomatic patients at risk of PAH and 20 healthy controls underwent a cardiopulmonary exercise test and were assessed for quality of life (QOL). Patients had a pulmonary artery catheter in situ during the exercise test. RESULTS Seventeen subjects had exercise-induced PAH (EIPAH), which we defined as mPAP ≤ 25 mm Hg at rest, and mPAP > 30 mm Hg and pulmonary artery wedge pressure <20 mm Hg on exercise. These subjects had reduced peak exercise cardiac output (72% ± 19% predicted). Further, compared with matched controls, subjects with EIPAH had reduced peak oxygen consumption (1.2 ± 0.4 vs 1.7 ± 0.5 L · min, P < 0.05), an elevated ventilatory equivalent for carbon dioxide (41.0 ± 7.3 vs 31.0 ± 2.9, P < 0.05) and reduced end-tidal carbon dioxide tension (32.6 ± 3.6 vs 39.4 ± 2.7 mm Hg, P < 0.05) at the anaerobic threshold. These exercise abnormalities were associated with impaired QOL (P < 0.05). CONCLUSIONS Elevated pulmonary artery pressure on exercise can be associated with hemodynamic and ventilatory abnormalities typical of PAH, along with impaired exercise capacity and reduced QOL.

A comparison of the acute haemodynamic response to aerobic and resistance exercise in subjects with exercise-induced pulmonary arterial hypertension

BackgroundThe Cambridge Pulmonary Hypertension Outcome Review (CAMPHOR) and the Medical Outcomes Study Short Form 36 (SF-36) are widely used to assess patient-reported outcome in individuals with pulmonary hypertension (PH). The aim of the study was to compare the psychometric properties of the two measures.MethodsParticipants were recruited from specialist PH centres in Australia and New Zealand. Participants completed the CAMPHOR and SF-36 at two time points two weeks apart. The SF-36 is a generic health status questionnaire consisting of 36 items split into 8 sections. The CAMPHOR is a PH-specific measure consisting of 3 scales; symptoms, activity limitations and needs-based QoL. The questionnaires were assessed for distributional properties (floor and ceiling effects), internal consistency (Cronbachs alpha), test-retest reliability and construct validity (scores by World Health Organisation functional classification).ResultsThe sample comprised 65 participants (mean (SD) age = 57.2 (14.5) years; n(%) male = 14 (21.5%)). Most of the patients were in WHO class 2 (27.7%) and 3 (61.5%). High ceiling effects were observed for the SF-36 bodily pain, social functioning and role emotional domains. Test-retest reliability was poor for six of the eight SF-36 domains, indicating high levels of random measurement error. Three of the SF-36 domains did not distinguish between WHO classes. In contrast, all CAMPHOR scales exhibited good distributional properties, test retest reliability and distinguished between WHO functional classes.ConclusionsThe CAMPHOR exhibited superior psychometric properties, compared with the SF-36, in the assessment of PH patient-reported outcome.

Measurement properties of the 6-min walk test in individuals with exercise-induced pulmonary arterial hypertension.

BackgroundAdvances in the understanding and management of pulmonary arterial hypertension have enabled earlier diagnosis and improved prognosis. However, despite best available therapy, symptoms of exertional dyspnoea and fatigue are commonly reported and result in a reduced capacity to perform daily activities and impaired quality of life. Exercise training has demonstrated efficacy in individuals with other respiratory and cardiovascular diseases. Historically, however, exercise training has not been utilised as a form of therapy in pulmonary arterial hypertension due to the perceived risk of sudden cardiac death and the theoretical possibility that exercise would lead to worsening pulmonary vascular haemodynamics and deterioration in right heart function. Now, with the advances in pharmaceutical management, determining the safety and benefits of exercise training in this population has become more relevant. Only three studies of supervised exercise training in pulmonary arterial hypertension have been published. These studies demonstrated improvements in exercise capacity and quality of life, in the absence of adverse events or clinical deterioration. However, these studies have not utilised an outpatient-based, whole body exercise training program, the most common format for exercise programs within Australia. It is uncertain whether this form of training is beneficial and capable of producing sustained benefits in exercise capacity and quality of life in this population.Design/MethodsThis randomised controlled trial will determine whether a 12 week, outpatient-based, supervised, whole body exercise training program, followed by a home-based exercise program, is safe and improves exercise capacity and quality of life in individuals with pulmonary arterial hypertension. This study aims to recruit 34 subjects who will be randomly allocated to the exercise group (supervised exercise training 3 times a week for 12 weeks, followed by 3 sessions per week of home exercise for 12 weeks) or the control group (usual medical care). Subjects will be assessed at baseline, 12 weeks and 24 weeks.DiscussionThis study will determine whether outpatient-based, whole body exercise training is beneficial and safe in individuals with pulmonary arterial hypertension. Additionally, this study will contribute to clinical practice guidelines for this patient population.Trial registrationAustralia and New Zealand Clinical Trials Register (ANZCTR): ACTRN12609000502235

Australian perspective regarding recommendations for physical activity and exercise rehabilitation in pulmonary arterial hypertension.

BACKGROUND The aim of this study was to compare measures of exercise capacity, health-related quality of life (HRQoL), muscle force, lung function and feelings of anxiety and depression in people after curative intent treatment for NSCLC with age and gender-matched healthy controls. METHODS This cross-sectional study included 23 participants (68 ± 10yr; 16 females), 6-10 weeks after lobectomy for NSCLC or, for those who received adjuvant chemotherapy, 4-8 weeks after their last cycle. The study also included 20 age and gender-matched healthy controls (69 ± 5yr; 13 females). All participants underwent measurements of exercise capacity (cycle-ergometry test [CPET] and 6-min walk test [6MWT]), HRQoL (Short-Form 36 general health survey [SF-36]), handgrip force, quadriceps torque, lung function and feelings of anxiety and depression. RESULTS When compared with data collected in healthy controls, those in the NSCLC group demonstrated impairments in the peak rate of oxygen consumption (15 ± 3 versus 24 ± 7 ml kg(-1)·min(-1); p < 0.001) and maximum work rate (75 ± 25 versus 127 ± 51Watts; p < 0.001) measured during the CPET, and 6-min walk distance (494 ± 77 versus 649 ± 61 m; p < 0.001). Similarly, impairments were demonstrated in all domains of the SF-36 (p < 0.01 for all), isometric handgrip force (28 ± 7 versus 34 ± 10 kg; p = 0.02), and all measures of lung function (p ≤ 0.001 for all). A higher score for depression was also seen (3.0 ± 2.5 versus 1.5 ± 1.6; p = 0.03). There was no difference between the groups in isometric quadriceps torque or feelings of anxiety. CONCLUSIONS After curative intent treatment for NSCLC, compared to healthy controls, impairments were demonstrated in laboratory and field-based measures of exercise capacity, HRQoL, isometric handgrip force and lung function. Although people after curative intent treatment for NSCLC reported greater feelings of depression, these levels were below those considered clinically relevant. These findings suggest that people after curative intent treatment for NSCLC may benefit from rehabilitative strategies to optimise exercise capacity and HRQoL.