Respiratory and limb muscle dysfunction in pulmonary arterial hypertension: a role for exercise training?

Effects of Inspiratory Muscle Training in Patients With Pulmonary Hypertension

The study aimed to examine the effects of inspiratory muscle training (IMT) in patients with pulmonary hypertension (PH). A total of 24 patients with PH were included in the randomized controlled evaluator-blind study. IMT was performed at 40% to 60% of the maximal inspiratory pressure for 30 min/d, 7 d/wk (1 day supervised) for 8 weeks. Respiratory muscle strength, dyspnea, diaphragm thickness (DT), pulmonary functions, 24-hour ambulatory blood pressure (BP), arterial stiffness, exercise capacity, upper extremity functional exercise capacity, physical activity levels, fatigue, anxiety-depression levels, activities of daily living (ADL), and quality of life were evaluated. A total of 24 patients (treatment = 12, control = 12) completed the 8-week follow-up. There was no significant difference between the patient groups in terms of demographic and clinical characteristics (p >0.05). Considering the change between the groups in the treatment and control groups, brachial and central BP, dyspnea, respiratory muscle strength, DT in total lung capacity, knee extension muscle strength, functional exercise capacity, upper extremity functional exercise capacity, physical activity, ADL, fatigue, anxiety, and quality of life improved in favor of the IMT group (p <0.05). In conclusion, IMT has improved brachial and central BP, dyspnea, respiratory muscle strength, DT in total lung capacity, knee extension muscle strength, functional exercise capacity, upper extremity functional exercise capacity, physical activity, ADL, fatigue, anxiety, and quality of life compared with the control group. IMT is an effective method in cardiopulmonary rehabilitation for patients with PH.

Pulmoner Arteriyel Hipertansiyonlu Hastalarda İnspiratuar Kas Eğitiminin Fonksiyonel Egzersiz Kapasitesi ve Yaşam Kalitesi Üzerine Etkisi: Bir Sistematik Derleme

Pulmoner Arteriyal Hipertansiyon hastalarında, hastalığın erken dönemlerinde semptomlar eforla ortaya çıkarken, hastalığın ileri evrelerinde dinlenme durumunda da gözlenebilir. Pulmoner Arteriyal Hipertansiyon hastaları için optimize edilmiş tıbbi tedavi bulunmasına rağmen, çoğu Pulmoner Arteriyal Hipertansiyon hastası düşük egzersiz kapasitesi ve yaşam kalitesinden şikayetçidir. Pulmoner Arteriyal Hipertansiyon tedavi parametrelerinden biri pulmoner rehabilitasyondur. Pulmoner rehabilitasyon muldisipliner bir yaklaşımdır. Pulmoner Arteriyal Hipertansiyon için en önemli bileşeni fizyoterapi programıdır. Kişiye özel fizyoterapi programları egzersiz eğitimi, solunum kas eğitimi, hasta eğitimi bileşenlerinden oluşmaktadır. Solunum kas kuvveti eğitimi daha çok spesifik olarak İnspiratuar Kas Eğitimi şeklinde uygulanmaktadır. Pulmoner Arteriyal Hipertansiyonlu hastalar için İnspiratuar Kas Eğitimi uygulamasının genel etkilerini araştıran ve konu alan çalışma sayısı azdır. Bu çalışmanın amacı Pulmoner Arteriyal Hipertansiyonlu hastalarda İnspiratuar Kas Eğitimi’nin hastanın fonksiyonel egzersiz kapasitesinin ve yaşam kalitesinin artmasında etkili midir? sorusunu cevaplamaktır. Ocak 2022 tarihinden önce PubMed, Web of Science, Cochrane Library olmak üzere üç ana veri tabanında arama yapıldı. Arama son 5 yılda yayınlanan randomize kontrollü prospektif çalışmalar olacak şekilde sınırlandırıldı. Pulmoner Arteriyal Hipertansiyonlu hastalarda İnspiratuar Kas Eğitimi uygulanan çalışmalar dahil edildi. Tam metinler okunduktan sonra dahil edilme kriterlerine uygun iki çalışma bulundu. Bu yayınların tümü randomize kontrollü prospektif çalışmalardı. Çalışmalar incelendiğinde, Pulmoner Arteriyal Hipertansiyonlu hastalarda İnspiratuar Kas Eğitimi uygulamasının, fonksiyonel egzersiz kapasitesini ve inspiratuar kas kuvvetini arttırdığı ancak yaşam kalitesini arttırmadaki etkinliğinin belirsiz olduğu sonucuna varıldı.

Exercise-based rehabilitation programmes for pulmonary hypertension

BACKGROUND

Individuals with pulmonary hypertension (PH) have reduced exercise capacity and quality of life. Despite initial concerns that exercise training may worsen symptoms in this group, several studies have reported improvements in functional capacity and well-being following exercise-based rehabilitation.

OBJECTIVES

To evaluate the benefits and harms of exercise-based rehabilitation for people with PH compared with usual care or no exercise-based rehabilitation.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest search date was 28 June 2022.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) in people with PH comparing supervised exercise-based rehabilitation programmes with usual care or no exercise-based rehabilitation.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our primary outcomes were 1. exercise capacity, 2. serious adverse events during the intervention period and 3. health-related quality of life (HRQoL). Our secondary outcomes were 4. cardiopulmonary haemodynamics, 5. Functional Class, 6. clinical worsening during follow-up, 7. mortality and 8. changes in B-type natriuretic peptide. We used GRADE to assess certainty of evidence.

MAIN RESULTS

We included eight new studies in the current review, which now includes 14 RCTs. We extracted data from 11 studies. The studies had low- to moderate-certainty evidence with evidence downgraded due to inconsistencies in the data and performance bias. The total number of participants in meta-analyses comparing exercise-based rehabilitation to control groups was 462. The mean age of the participants in the 14 RCTs ranged from 35 to 68 years. Most participants were women and classified as Group I pulmonary arterial hypertension (PAH). Study durations ranged from 3 to 25 weeks. Exercise-based programmes included both inpatient- and outpatient-based rehabilitation that incorporated both upper and lower limb exercise. The mean six-minute walk distance following exercise-based rehabilitation was 48.52 metres higher than control (95% confidence interval (CI) 33.42 to 63.62; I² = 72%; 11 studies, 418 participants; low-certainty evidence), the mean peak oxygen uptake was 2.07 mL/kg/min higher than control (95% CI 1.57 to 2.57; I² = 67%; 7 studies, 314 participants; low-certainty evidence) and the mean peak power was 9.69 W higher than control (95% CI 5.52 to 13.85; I² = 71%; 5 studies, 226 participants; low-certainty evidence). Three studies reported five serious adverse events; however, exercise-based rehabilitation was not associated with an increased risk of serious adverse event (risk difference 0, 95% CI -0.03 to 0.03; I² = 0%; 11 studies, 439 participants; moderate-certainty evidence). The mean change in HRQoL for the 36-item Short Form (SF-36) Physical Component Score was 3.98 points higher (95% CI 1.89 to 6.07; I² = 38%; 5 studies, 187 participants; moderate-certainty evidence) and for the SF-36 Mental Component Score was 3.60 points higher (95% CI 1.21 to 5.98 points; I² = 0%; 5 RCTs, 186 participants; moderate-certainty evidence). There were similar effects in the subgroup analyses for participants with Group 1 PH versus studies of groups with mixed PH. Two studies reported mean reduction in mean pulmonary arterial pressure following exercise-based rehabilitation (mean reduction: 9.29 mmHg, 95% CI -12.96 to -5.61; I² = 0%; 2 studies, 133 participants; low-certainty evidence).

AUTHORS' CONCLUSIONS

In people with PH, supervised exercise-based rehabilitation may result in a large increase in exercise capacity. Changes in exercise capacity remain heterogeneous and cannot be explained by subgroup analysis. It is likely that exercise-based rehabilitation increases HRQoL and is probably not associated with an increased risk of a serious adverse events. Exercise training may result in a large reduction in mean pulmonary arterial pressure. Overall, we assessed the certainty of the evidence to be low for exercise capacity and mean pulmonary arterial pressure, and moderate for HRQoL and adverse events. Future RCTs are needed to inform the application of exercise-based rehabilitation across the spectrum of people with PH, including those with chronic thromboembolic PH, PH with left-sided heart disease and those with more severe disease.

Effectiveness of Respiratory Muscle Training in Adults With Pulmonary Hypertension. A Systematic Review and Meta-Analysis

BACKGROUND

Patients with pulmonary hypertension (PH) may have impaired exercise capacity and quality of life; this may possibly be due to the early onset of dyspnoea associated with respiratory muscle weakness. Respiratory muscle training could improve the condition of these patients, so this study aimed to determine, through a systematic review and meta-analysis, the effectiveness of respiratory muscle training in adult patients with PH.

METHODS

Medline, Embase, CENTRAL, clinical trial registries databases, and grey literature and reference lists of reviews related to the objective were searched up to March 2022. Controlled clinical trials comparing the effectiveness of respiratory muscle training with sham or no intervention in adults with PH were included. Records were independently screened by two authors. The primary outcomes were maximal and functional exercise capacity, quality of life, and dyspnoea. The secondary outcomes were respiratory muscle strength, physical activity, lung function, and adverse events. Two authors independently extracted data and the study quality was assessed using the Cochrane risk-of-bias tool 2 (RoB 2). The certainty of the evidence was assessed according to the GRADE approach.

RESULTS

A total of 5,524 records were screened, and seven randomised clinical trials (RCTs) (257 participants) were included. It was uncertain whether inspiratory muscle training (IMT), compared with sham IMT or no intervention, increased the distance walked in the 6-minute walk test (6MWT) (MD, 39 m; 95% CI, 20.72-57.39; I²=27%; four RCTs; very low certainty of evidence) and slightly decreased the perceived sensation of dyspnoea (MD, 0.5 points on the mMRC scale; 95% CI, -0.87 to -0.13; I²=0%; two RCTs; very low certainty of evidence). In addition, it was uncertain whether IMT had no effect on the emotional (SMD, -0.34; 95% CI, -1.06 to 0.38; I²=64%; three RCTs; very low certainty of evidence) and physical (SMD, 0.06; 95% CI, -0.41 to 0.52; I²=16%; three RCTs; very low certainty of evidence) component of quality of life.

CONCLUSIONS

It is uncertain whether IMT increases functional exercise capacity and slightly decreases the sensation of dyspnoea. In addition, it is uncertain whether IMT does not affect the quality of life. More RCTs and with a better methodological design are needed to increase the certainty of the evidence and determine the real effect of this intervention.

Evaluation of primary and accessory respiratory muscles and their influence on exercise capacity and dyspnea in pulmonary arterial hypertension

BACKGROUND

Skeletal and respiratory muscle disfunction has been described in pulmonary arterial hypertension (PAH), however, involvement of accessory respiratory muscles and their association with symptomatology in PAH is unclear.

OBJECTIVES

To assess the primary and accessory respiratory muscles and their influence on exercise tolerance and dyspnea.

METHODS

27 patients and 27 healthy controls were included. Serratus anterior (SA), pectoralis muscles (PM) and sternocleidomastoid (SCM) muscle strength were evaluated as accessory respiratory muscles, maximal inspiratory (MIP) and expiratory pressures (MEP) as primary respiratory muscles, and quadriceps as peripheral muscle. Exercise capacity was evaluated with 6-min walk test (6MWT), dyspnea with modified Medical Council Research (MMRC) and London Chest Activity of Daily Living (LCADL) scales.

RESULTS

All evaluated muscles, except SCM, and 6MWT were decreased in patient group (p < 0.01). SA was the most affected muscle among primary and accessory respiratory muscles (Cohen's-d = 1.35). All evaluated muscles significantly correlated to 6MWT (r = 0.428-0.525). A multivariate model including SA, SCM and MIP was the best model for predicting 6MWT (R = 0.606; R² = 0.368; p = 0.013) and SA strength had the most impact on the 6MWT (B = 1.242; β = 0.340). None of the models including respiratory muscles were able to predict dyspnea, however PM and SA strength correlated to LCADL _total (r = -0.493) and MMRC (r = -0.523), respectively.

CONCLUSION

SCM may be excessively used in PAH since it retains its strength. Considering the relationship of accessory respiratory muscles with exercise tolerance and dyspnea, monitoring the strength of these muscles in the clinical practice may help providing better management for PAH.

Effectiveness and safety of inspiratory muscle training in patients with pulmonary hypertension: A systematic review and meta-analysis

BACKGROUND

Inspiratory muscle training (IMT) is a simple and well-tolerated physical therapy that increases respiratory muscle strength and relieving the degree of dyspnea and fatigue. Therefore, it may be used as a transitional modality before exercise training or as a specific physical therapy intervention for those who are diagnosed with respiratory muscle weakness. However, the current evidence on IMT in pulmonary hypertension (PH) patients is inconclusive. The purpose of this systematic review and meta-analysis was to summarize the current role of IMT in this group of patients.

METHODS

PubMed, EMBASE, and Cochrane databases were searched through May 2022. Trials examining the feasibility and effectiveness of IMT in PH patients. Outcome measures included adverse events, training adherence and compliance, maximum inspiratory pressure (MIP), maximum expiratory pressure (MEP), forced vital capacity (FVC%), forced expiratory volume in 1 s (FEV1%), FEV1/FVC%, 6 min walk distance (6MWD), Peak VO2, dyspnea, and fatigue perception after the IMT training program. Only randomized controlled trials were included. The Cochrane Risk of Bias tool for controlled trials was adopted to assess study quality. Statistical heterogeneity was evaluated with the chi-square test and I 2 statistic. Mean differences and 95% confidence intervals (CIs) were estimated.

RESULTS

We ultimately identified four studies that met the criteria. These studies comprised 80 patients with 16 males and 64 females. The mean age was 53.25. The main types of PH were group I (pulmonary arterial hypertension, 95%) and group IV (chronic thromboembolic PH, 5%). No severe adverse events were reported in the included studies. IMT had a significant effect on improving MIP (18.89 cmH2O; 95% CI: 9.43-28.35, P < 0.001) and MEP (8.06 cmH2O; 95% CI: 2.39-13.73; P = 0.005), increase in the 6MWD (30.16 m; 95% CI: 1.53-58.79; P = 0.04). No significant improvement was found in pulmonary function (P > 0.05), and uncertain effect on the quality of life (QoL) score.

CONCLUSION

Based on currently limited evidence, IMT is an effective physical therapy for increasing respiratory muscle function and exercise capacity, but still a lack of evidence on dyspnea and fatigue levels, pulmonary function, and QoL in PH patients. There are reasons to believe that IMT is a promising intervention in PH patients, enriching rehabilitation options and serving as a bridge before formal exercise training. It is expected that IMT will play an important role in the future clinical pathway of physical therapy for this group of patients.

SYSTEMATIC REVIEW REGISTRATION

[https://www.crd.york.ac.uk/PROSPERO/logout.php], identifier [CRD42022335972].

Effects of Adding Respiratory Training to Osteopathic Manipulative Treatment on Exhaled Nitric Oxide Level and Cardiopulmonary Function in Patients With Pulmonary Arterial Hypertension

Limited research exists regarding nonpharmacologic management of pulmonary arterial hypertension (PAH), except for exercise training. The objective of this study was to investigate the effects of osteopathic manipulative treatment (OMT) alone and combined with respiratory training on fractional exhaled nitric oxide (FeNO), and cardiopulmonary function in patients with PAH. This single-blind, prospective, randomized controlled study included 54 patients with PAH who were randomly allocated to OMT, combined intervention, and control groups. The OMT group (n = 16) and combined intervention group (n = 16) received OMT and yoga respiratory training plus OMT, respectively, twice a week for 8 weeks. The control group (n = 16) received no intervention. All patients undertook an educational lecture. FeNO level, pulmonary function, 6-minute walk distance (6MWD), maximal inspiratory and expiratory pressures, and handgrip strength were assessed at baseline and 8 weeks. Combined intervention and OMT groups significantly improved all outcome measures after 8 weeks of treatment (p <0.01), except mean forced expiratory flow between 25% and 75% of forced vital capacity, which did not change in the OMT group (p >0.05). The control group showed significant deteriorations in 6MWD, inspiratory and peripheral muscle strength, and pulmonary function except peak expiratory flow at 8 weeks (p <0.05). The combined intervention group revealed significantly greater improvements of FeNO, 6MWD, respiratory and peripheral muscle strength, and pulmonary function except mean forced expiratory flow between 25% and 75% of forced vital capacity compared with the OMT group (p <0.05). All outcomes significantly improved in both intervention groups versus the control group (p <0.05). Our study demonstrated that adding respiratory training to OMT provided further benefit to FeNO level and cardiopulmonary function compared with OMT alone and that the OMT might be a useful and safe intervention for patients who cannot attend cardiac rehabilitation programs.

Exercise intolerance in pulmonary arterial hypertension: insight into central and peripheral pathophysiological mechanisms

Exercise intolerance is a cardinal symptom of pulmonary arterial hypertension (PAH) and strongly impacts patients' quality of life (QoL). Although central cardiopulmonary impairments limit peak oxygen consumption (V' O2peak ) in patients with PAH, several peripheral abnormalities have been described over the recent decade as key determinants in exercise intolerance, including impaired skeletal muscle (SKM) morphology, convective O2 transport, capillarity and metabolism indicating that peripheral abnormalities play a greater role in limiting exercise capacity than previously thought. More recently, cerebrovascular alterations potentially contributing to exercise intolerance in patients with PAH were also documented. Currently, only cardiopulmonary rehabilitation has been shown to efficiently improve the peripheral components of exercise intolerance in patients with PAH. However, more extensive studies are needed to identify targeted interventions that would ultimately improve patients' exercise tolerance and QoL. The present review offers a broad and comprehensive analysis of the present literature about the complex mechanisms and their interactions limiting exercise in patients and suggests several gaps in knowledge that need to be addressed in the future for a better understanding of exercise intolerance in patients with PAH.

Long-Term Effect of an Exercise Training Program on Physical Functioning and Quality of Life in Pulmonary Hypertension: A Randomized Controlled Trial

The aim of this study was to evaluate the effects of a 6-month combined aerobic and strength exercise training program on functional and psychological aspects and health-related quality of life in patients with PH and to evaluate its longer-term impact. In total, 22 stable patients (mean age 53.9 ± 13.8, 13 female) with pulmonary hypertension of World Health Organization (WHO) class I-III participated in a nine-month study. They were randomly assigned into two groups: Group A participated in a 6-month combined aerobic and strength exercise training program, whereas Group B remained untrained. All patients underwent physical and psychological assessment at baseline and at month 6 (after completing the exercise program) and physical assessment after 9 months (3 months posttraining). After the 6-month exercise training program, patients of Group A significantly improved their physical (6MWD, STS 10 rep, STS 20 rep, TUG, lower limb strength, cardiopulmonary exercise time, METs, peak VO₂, VCO₂, and VE/VCO₂ slope) and psychological aspects (SF-36, STAI, and BDI). Between the two groups, differences were observed at the 6MWD (95% CI: 36.2-64.6, η² = 0.72), STS 10 rep (95% CI: 6.6-2.2, η² = 0.4), STS 20 rep (95% CI: 10.8-2.4, η² = 0.34), lower limb strength (95% CI: 7.2-3.6, η² = 0.38), cardiopulmonary exercise time (95% CI: 0.1-3.3, η² = 0.2), and VCO₂ (95% CI: 0.1-0.5, η² = 0.2). Additionally, psychological changes were noted at SF-36, PCS (95% CI: 3.6-14.8, η² = 0.35), MCS (95% CI: 1.3-16.1, η² = 0.22), TCS (95% CI: 1.3-16.1, η² = 0.22), and STAI (95% CI: 1.8-28.2, η² = 0.18). The favorable results of exercise were maintained at the 3-month posttraining follow-up assessment. No exercise-induced complications were observed throughout the study. In conclusion, a long-term exercise training program is a safe and effective intervention to improve functional status, psychological aspects, and health-related quality of life in patients with PH.

Continuous Aerobic Exercise Prevents Detrimental Remodeling and Right Heart Myocyte Contraction and Calcium Cycling Dysfunction in Pulmonary Artery Hypertension

ABSTRACT

Pulmonary artery hypertension (PAH) imposes right heart and lung detrimental remodeling which impairs cardiac contractility, physical effort tolerance, and survival. The effects of an early moderate-intensity continuous aerobic exercise training on the right ventricle and lung structure, and on contractility and the calcium (Ca2+) transient in isolated myocytes from rats with severe PAH induced by monocrotaline were analyzed. Rats were divided into control sedentary (CS), control exercise (CE), monocrotaline sedentary (MS), and monocrotaline exercise (ME) groups. Animals from control exercise and ME groups underwent a moderate-intensity aerobic exercise on a treadmill (60 min/d; 60% intensity) for 32 days, after a monocrotaline (60 mg/kg body weight i.p.) or saline injection. The pulmonary artery resistance was higher in MS than in control sedentary (1.36-fold) and was reduced by 39.39% in ME compared with MS. Compared with MS, the ME group presented reduced alveolus (17%) and blood vessel (46%) wall, fibrosis (25.37%) and type I collagen content (55.78%), and increased alveolus (52.96%) and blood vessel (146.97%) lumen. In the right ventricle, the ME group exhibited diminished hypertrophy index (25.53%) and type I collagen content (40.42%) and improved myocyte contraction [ie, reduced times to peak (29.27%) and to 50% relax (13.79%)] and intracellular Ca2+ transient [ie, decreased times to peak (16.06%) and to 50% decay (7.41%)] compared with MS. Thus, early moderate-intensity continuous aerobic exercise prevents detrimental remodeling in the right heart and lung increases in the pulmonary artery resistance and dysfunction in single myocyte contraction and Ca2+ cycling in this model.

Redox Regulation, Oxidative Stress, and Inflammation in Group 3 Pulmonary Hypertension

Group 3 pulmonary hypertension (PH), which occurs secondary to hypoxia lung diseases, is one of the most common causes of PH worldwide and has a high unmet clinical need. A deeper understanding of the integrative pathological and adaptive molecular mechanisms within this group is required to inform the development of novel drug targets and effective treatments. The production of oxidants is increased in PH Group 3, and their pleiotropic roles include contributing to disease progression by promoting prolonged hypoxic pulmonary vasoconstriction and pathological pulmonary vascular remodeling, but also stimulating adaptation to pathological stress that limits the severity of this disease. Inflammation, which is increasingly being viewed as a key pathological feature of Group 3 PH, is subject to complex regulation by redox mechanisms and is exacerbated by, but also augments oxidative stress. In this review, we investigate aspects of this complex crosstalk between inflammation and oxidative stress in Group 3 PH, focusing on the redox-regulated transcription factor NF-κB and its upstream regulators toll-like receptor 4 and high mobility group box protein 1. Ultimately, we propose that the development of specific therapeutic interventions targeting redox-regulated signaling pathways related to inflammation could be explored as novel treatments for Group 3 PH.

The Efficacy of Outpatient Pulmonary Rehabilitation After Bilateral Lung Transplantation

PURPOSE

Pulmonary rehabilitation (PR) is advocated in the pre- and post-lung transplantation (LTx) periods. However, there is limited literature on the benefit of PR post-LTx. The aim of this study was to investigate the efficacy of an outpatient, multidisciplinary, comprehensive PR program in bilateral LTx recipients in the early period after LTx.

METHOD

Twenty-three LTx recipients were referred to the PR center. Change in incremental and endurance shuttle walk tests, hand and quadriceps strength, respiratory muscle strength (maximum inspiratory/expiratory pressure), dyspnea (Medical Research Council score), quality of life (St George's Respiratory Questionnaire, Chronic Respiratory Questionnaire), and psychological status (Hospital Anxiety Depression Scale) were compared pre- and post-PR.

RESULTS

Seventeen of 23 (74%) recipients completed PR, comprising 15 male and 2 female patients whose median age was 51 yr. The initiation of the program was 75 ± 15 d after LTx. The incremental shuttle walk test distance was predicted as 23% before PR and it increased to 36% after PR (P < .001); the endurance shuttle walk test distance also increased (P < .01). Significant improvement was seen in upper and lower extremity strength, and St George's Respiratory Questionnaire and Chronic Respiratory Questionnaire scores and Hospital Anxiety Depression Scale scores reflected less anxiety and depressive symptoms. Furthermore, body mass and fat-free mass indices, maximum inspiratory pressure, and maximum expiratory pressure improved significantly. There was no significant change in forced expiratory volume in the first second of expiration, forced vital capacity, or Medical Research Council scores.

CONCLUSION

This study demonstrated that patients who attended PR within 3 mo of bilateral LTx showed improvements in exercise capacity, respiratory muscle strength, quality of life, body composition, and psychological status.

Inspiratory Muscle Training Improves Inspiratory Muscle Strength and Functional Exercise Capacity in Pulmonary Arterial Hypertension and Chronic Thromboembolic Pulmonary Hypertension: A Pilot Randomised Controlled Study

BACKGROUND

Exercise intolerance is present even in the early stages of pulmonary arterial hypertension (PAH) and is associated with poorer prognosis. Respiratory muscle dysfunction is common and may contribute to exercise limitation. We sought to investigate the effects of inspiratory muscle training (IMT) to improve exercise capacity in PAH.

METHODS

Adults with PAH were prospectively recruited and randomly assigned to either IMT or a control group. At baseline and after 8 weeks, assessment of respiratory muscle function, pulmonary function, neurohormonal activation, 6-minute walk distance and cardiopulmonary exercise testing variables were conducted. Inspiratory muscle strength was assessed by maximal static inspiratory pressure (PImax). The IMT group performed two cycles of 30 breaths at 30-40% of their PImax 5 days a week for 8 weeks.

RESULTS

Twelve (12) PAH patients (60±14 years, 10 females) were recruited and randomised (six in the IMT group and six in the control group). After 8 weeks, the IMT group improved PImax by 31 cmH₂O compared with 10 cmH₂O in controls, p=0.02. Following IMT, 6-minute walk distance improved by 24.5 m in the IMT group and declined by 12 m in the controls (mean difference 36.5 m, 95% CI 3.5-69.5, p=0.03). There was no difference in peak oxygen uptake between-groups (mean difference 0.4 mL/kg/min, 95% CI -2.6 to 3.4, p=0.77). There was no difference in the mean change between-groups in neurohormonal activation or pulmonary function.

CONCLUSION

In this pilot randomised controlled study, IMT improved PImax and 6-minute walk distance in PAH patients.

Effects of exercise rehabilitation training on patients with pulmonary hypertension

Pulmonary hypertension (PH) comprises a group of pathophysiological syndromes characterized by elevated pulmonary artery pressure and pulmonary vascular resistance, which lead to right ventricular overload, and even right heart failure. PH has a poor prognosis and severely leads to a decline in quality of life. Historically, patients with PH were advised to limit their physical activity. However, an increasing number of studies have reported the safety and efficacy of exercise rehabilitation training in PH. This review briefly examined and summarized the effects of exercise rehabilitation training on PH patients reported in the recent literature. The findings of the reviewed studies indicate that exercise rehabilitation training in PH patients has beneficial effects in terms of exercise capacity and quality of life, vascular and right ventricle remodelling, inflammatory response, muscular function and oxidative stress. However, the underlying mechanisms and appropriate exercise strategies (e.g. the duration and intensity of exercise) still need to be explored. In conclusion, exercise rehabilitation training of the appropriate intensity and frequency can improve the prognosis and quality of life of PH patients. The training should be monitored by professional staff and be provided as an adjunct to pharmacological treatment. Larger clinical trials are required to confirm the safety and efficacy of exercise rehabilitation training in PH.

Endurance exercise training in pulmonary hypertension increases skeletal muscle electron transport chain supercomplex assembly

Pulmonary hypertension is associated with pronounced exercise intolerance (decreased V ċ O₂ max) that can significantly impact quality of life. The cause of exercise intolerance in pulmonary hypertension remains unclear. Mitochondrial supercomplexes are large respiratory assemblies of individual electron transport chain complexes which can promote more efficient respiration. In this study, we examined pulmonary hypertension and exercise-induced changes in skeletal muscle electron transport chain protein expression and supercomplex assembly. Pulmonary arterial hypertension was induced in rats with the Sugen/Hypoxia model (10% FiO₂, three weeks). Pulmonary arterial hypertension and control rats were assigned to an exercise training protocol group or kept sedentary for one month. Cardiac function and V ċ O₂ max were assessed at the beginning and end of exercise training. Red (Type 1—oxidative muscle) and white (Type 2—glycolytic muscle) gastrocnemius were assessed for changes in electron transport chain complex protein expression and supercomplex assembly via SDS- and Blue Native-PAGE. Results showed that pulmonary arterial hypertension caused a significant decrease in V ċ O₂ max via treadmill testing that was improved with exercise (P < 0.01). Decreases in cardiac output and pulmonary acceleration time due to pulmonary arterial hypertension were not improved with exercise. Pulmonary arterial hypertension reduced expression in individual electron transport chain complex protein expression (NDUFB8 (CI), SDHB (CII), Cox IV (CIV), but not UQCRC2 (CIII), or ATP5a (CV)) in red gastrocnemius muscle. Both red gastrocnemius and white gastrocnemius electron transport chain expression was unaffected by exercise. However, non-denaturing Blue Native-PAGE analysis of mitochondrial supercomplexes demonstrated increases with exercise training in pulmonary arterial hypertension in the red gastrocnemius but not white gastrocnemius muscle. Pulmonary arterial hypertension-induced exercise intolerance is improved with exercise and is associated with muscle type specific alteration in mitochondrial supercomplex assembly and expression of mitochondrial electron transport chain proteins.

Patient assessment and selection for pulmonary rehabilitation

Pulmonary rehabilitation (PR) is beneficial for people with several forms of chronic respiratory disease. Given the existing limitations on availability of PR services, it is important to identify participants who are most likely to benefit from it. Identification of criteria for patient referral to PR is challenging, as chronic respiratory diseases and their medical and psychosocial co-morbidities place a complex and multifaceted burden on patients. Although research studies have attempted to identify key parameters predictive of 'responsiveness to PR', to date no firm physiological, psychosocial or other criteria exist by which optimal patient candidacy can be determined. Moreover, individual factors do not reliably predict successful multidimensional PR outcomes. In general, individuals who remain symptomatic with dyspnoea, fatigue and exercise intolerance; who have difficulty performing activities of daily living (ADL); and who are having difficulty coping with or managing their disease despite optimized pharmacological therapy are potential candidates for PR. Patient assessment and outcome measurement are core essential features of PR. To be considered as a PR programme, rehabilitation programmes must demonstrate, at a minimum, assessment and outcome measurement in regard to exercise capacity, dyspnoea and health-related quality of life. Additional parameters, including physical activity, nutritional status, tobacco use status, patient knowledge and self-efficacy, performance of ADL, fatigue, disease exacerbations, hospitalizations and other urgent healthcare utilization, and behavioural outcomes, including coping styles, patient satisfaction and programme metrics, are other relevant and important aspects of patient assessment and outcome measurement that should be considered and undertaken in PR, where feasible.

ERS statement on exercise training and rehabilitation in patients with severe chronic pulmonary hypertension

Objectives of this European Respiratory Society task force were to summarise current studies, to develop strategies for future research and to increase availability and awareness of exercise training for pulmonary hypertension (PH) patients.

An evidence-based approach with clinical expertise of the task force members, based on both literature search and face-to-face meetings was conducted. The statement summarises current knowledge and open questions regarding clinical effects of exercise training in PH, training modalities, implementation strategies and pathophysiological mechanisms.

In studies (784 PH patients in total, including six randomised controlled trials, three controlled trials, 10 prospective cohort studies and four meta-analyses), exercise training has been shown to improve exercise capacity, muscular function, quality of life and possibly right ventricular function and pulmonary haemodynamics. Nevertheless, further studies are needed to confirm these data, to investigate the impact on risk profiles and to identify the most advantageous training methodology and underlying pathophysiological mechanisms.

As exercise training appears to be effective, cost-efficient and safe, but is scarcely reimbursed, support from healthcare institutions, commissioners of healthcare and research funding institutions is greatly needed. There is a strong need to establish specialised rehabilitation programmes for PH patients to enhance patient access to this treatment intervention.

Cardiopulmonary rehabilitation program impact on prognostic markers in selected patients with resting and exercise-induced ventilatory inefficiency: a clinical trial

[Purpose] Ventilatory limitation is a common problem in patients with chronic heart failure and pulmonary hypertension. Excess ventilation may arise from augmented ventilatory drive, over activity of chemoreceptors and muscle ergoreceptors, or premature onset of lactic acidosis. Exertional dyspnea can cause limitations in the activities of daily living and as a result, reduced quality of life for these patients. The aim of the present study was to evaluate the effect of cardiopulmonary rehabilitation program on ventilatory efficiency for these patients. [Subjects and Methods] Twenty five patients with chronic heart failure and twenty five patients with pulmonary hypertension and only forty of them completed the study. The training program consisted of interval aerobic training program, based on the results of cardiopulmonary exercise testing. Training period was about five months. Outcomes were ventilatory equivalent for CO2, (VE/VCO2 at anaerobic threshold), VO2 at anaerobic threshold, VO2 max and peak work load. Echocardiography parameters were also measured; right ventricular systolic pressure for patients with pulmonary hypertension and ejection fraction for patients with chronic heart failure. [Results] Both groups showed an improvement in ventilation during exercise in favor of patients with pulmonary hypertension. VE/VCO2 decreased by 6.65 in pulmonary hypertension and by 2.9 in chronic heart failure. Right ventricular systolic pressure decreased by 12.05 mmHg in pulmonary hypertension and ejection fraction increased by 17.74% in chronic heart failure. [Conclusion] Physical therapy cardiopulmonary rehabilitation should be considered in managing patients with ventilatory limitation such as pulmonary hypertension and chronic heart failure.

A study of clinical and physiological relations of daily physical activity in precapillary pulmonary hypertension

Daily physical activity is reduced in precapillary pulmonary hypertension (PH), but the underlying mechanisms are inadequately explored. We sought to investigate clinical and physiological relations of daily physical activity and profile differences between less and more active patients with precapillary PH. A prospective, cross-sectional study of 20 patients with precapillary PH who undertook 1) a comprehensive clinical assessment, 2) a preliminary treadmill test, 3) 7-day monitoring of daily walking intensity with triaxial accelerometry, and 4) a personalized treadmill test corresponding to the individual patient mean daily walking intensity with real-time physiological measurements. Significant clinical correlations with individual patient mean walking intensity [1.71 ± 0.27 (SD) m/s²] were observed for log-transformed N-terminal probrain natriuretic peptide (log NT-proBNP; r = -0.75, P = <.001), age (r = -0.70, P = 0.001), transfer factor for carbon monoxide %predicted (r = 0.51, P = 0.022), and 6-min walk distance (r = 0.50, P = 0.026). Significant physiological correlations were obtained for heart rate reserve (r = 0.68, P = 0.001), quadriceps tissue oxygenation index (Q-[Formula: see text]; r = 0.58, P = 0.008), change in Q-[Formula: see text] from rest (r = 0.60, P = 0.006), and ventilatory equivalent for oxygen uptake (r = -0.56, P = 0.013). Stepwise multiple regression analyses retained log NT-proBNP (R² = 0.55), heart rate reserve (R² = 0.44), and Q-[Formula: see text] (R² = 0.13) accounting for a significant variance in individual walking intensity. Less active patients had greater physical activity-induced cardiopulmonary impairment, worse quadriceps oxygenation profile, and compromised health-related quality of life compared with more active patients. These preliminary findings suggest a significant relation between right ventricular and peripheral muscle oxygenation status and reduced daily physical activity in precapillary PH. Further research is warranted to unravel the physiological determinants, establish clinical predictors, and identify beneficial interventions.NEW & NOTEWORTHY Daily physical activity holds promise to be a meaningful, patient-related outcome measure in pulmonary hypertension. In this study, novel findings in a representative sample of patients with precapillary pulmonary hypertension link reduced daily walking activity, as measured by triaxial accelerometry, with compromised right ventricular and pulmonary vascular status, peripheral muscle oxygenation, and health-related quality of life, providing a preliminary insight into the physiological mechanisms and clinical predictors of daily physical activity in precapillary pulmonary hypertension.

Randomised controlled trial examining the effect of an outpatient exercise training programme on haemodynamics and cardiac MR parameters of right ventricular function in patients with pulmonary arterial hypertension: the ExPAH study protocol

INTRODUCTION

Pulmonary hypertension (PH) is a potentially life-threatening condition characterised by elevated pulmonary artery pressure. Early stage PH patients are often asymptomatic. Disease progression is associated with impairment of right ventricular function and progressive dyspnoea. Current guidelines recommend exercise training (grade IIa, level B). However, many questions remain regarding the mechanisms of improvement, intensity of supervision and optimal frequency, duration and intensity of exercise. This study will assess the effect of an outpatient rehabilitation programme on haemodynamics and cardiac right ventricular function in patients with pulmonary arterial hypertension (PAH), a subgroup of PH.

METHODS AND ANALYSIS

This randomised controlled trial involves both a major urban tertiary and smaller regional hospital in New South Wales, Australia. The intervention will compare an outpatient rehabilitation programme with a control group (home exercise programme). Participants will be stable on oral PAH-specific therapy. The primary outcome measure will be right ventricular ejection fraction measured by cardiac MRI. Secondary outcomes will include haemodynamics measured by right heart catheterisation, endurance, functional capacity, health-related quality of life questionnaires and biomarkers of cardiac function and inflammation.

ETHICS APPROVAL AND DISSEMINATION

Ethical approval has been granted by St Vincent's Hospital, Sydney (HREC/14/SVH/341). Results of this study will be disseminated through presentation at scientific conferences and in scientific journals.

TRIAL REGISTRATION NUMBER

ACTRN12615001041549; pre-results.

Exercise-based rehabilitation programmes for pulmonary hypertension

BACKGROUND

Individuals with pulmonary hypertension (PH) have reduced exercise capacity and quality of life. Despite initial concerns that exercise training may worsen symptoms in this group, several studies have reported improvements in functional capacity and well-being following exercise-based rehabilitation in PH.

OBJECTIVES

To assess the efficacy and safety of exercise-based rehabilitation for people with PH. Primary outcomes were exercise capacity, adverse events during the intervention period and health-related quality of life (HRQoL). Secondary outcomes included cardiopulmonary haemodynamics, functional class, clinical worsening during follow-up, mortality and changes in B-type natriuretic peptide.

SEARCH METHODS

We searched the Cochrane Airways Specialised Register of Trials up to August 2016, which is based on regular searches of CINAHL, AMED, Embase, PubMed, MEDLINE, PsycINFO and registries of clinical trials. In addition we searched CENTRAL and the PEDro database up to August 2016 and handsearched relevant journals.

SELECTION CRITERIA

All randomised controlled trials (RCTs) focusing on exercise-based rehabilitation programmes for PH.

DATA COLLECTION AND ANALYSIS

Two reviewers extracted data independently. For binary outcomes, we calculated odds ratios and their 95% confidence interval (CI), on an intention-to-treat basis. For continuous data, we estimated the mean difference (MD) between groups and its 95% CI. We employed a random-effects model for analyses. We assessed risk of bias for included studies and created 'Summary of findings' tables using GRADE.

MAIN RESULTS

We included six RCTs and were able to extract data from five studies. The majority of participants were Group I pulmonary artery hypertension (PAH). Study duration ranged from three to 15 weeks. Exercise programmes included both inpatient- and outpatient-based rehabilitation that incorporated both upper and lower limb exercise. The mean six-minute walk distance following exercise training was 60.12 metres higher than control (30.17 to 90.07 metres, n = 165, 5 RCTs, low-quality evidence; minimal important difference was 30 metres), the mean peak oxygen uptake was 2.4 ml/kg/minute higher (1.4 to 3.4 ml/kg/min, n = 145, 4 RCTs, low-quality evidence) and the mean peak power in the intervention groups was 16.4 W higher (10.9 to 22.0 higher, n = 145, 4 RCTs, low-quality evidence). The mean change in HRQoL for the SF-36 physical component score was 4.63 points higher (0.80 to 8.47 points, n = 33, 2 RCTs, low-quality evidence) and for the SF-36 mental component score was 4.17 points higher (0.01 to 8.34 points; n = 33; 2 RCTs, low-quality evidence). One study reported a single adverse event, where a participant stopped exercise training due to lightheadedness.

AUTHORS' CONCLUSIONS

In people with PH, exercise-based rehabilitation results in clinically relevant improvements in exercise capacity. Exercise training was not associated with any serious adverse events. Whilst most studies reported improvements in HRQoL, these may not be clinically important. Overall, we assessed the quality of the evidence to be low. The small number of studies and lack of information on participant selection makes it difficult to generalise these results across the spectrum of people with PH.

Physical activity and training in sarcoidosis: review and experience-based recommendations

INTRODUCTION

Sarcoidosis is a multisystemic inflammatory disorder with a great variety of symptoms, including fatigue, dyspnea, pain, reduced exercise tolerance and muscle strength. Physical training has the potential to improve exercise capacity and muscle strength, and reduce fatigue. The aim of this review and survey was to present information about the role of physical training in sarcoidosis and offer practical guidelines.

AREAS COVERED

A systematic literature review guided an international consensus effort among sarcoidosis experts to establish practice-basic recommendations for the implementation of exercise as treatment for patients with various manifestations of sarcoidosis. International sarcoidosis experts suggested considering physical training in symptomatic patients with sarcoidosis. Expert commentary: There is promising evidence of a positive effect of physical training. Recommendations were based on available data and expert consensus. However, the heterogeneity of these patients will require modification and program adjustment of the standard rehabilitation format for e.g. COPD or interstitial lung diseases. An optimal training program (types of exercise, intensities, frequency, duration) still needs to be defined to optimize training adjustments, especially reduction of fatigue. Further randomized controlled trials are needed to consolidate these findings and optimize the comprehensive care of sarcoidosis patients.