Benefits of combined aerobic/resistance/inspiratory training in patients with chronic heart failure. A complete exercise model? A prospective randomised study. Int J Cardiol. 2013;167:1967-1972. [PMID: 22658571 DOI: 10.1016/j.ijcard.2012.05.019]

Ergophysiological evaluation of heart failure patients with reduced ejection fraction undergoing exercise-based cardiac rehabilitation: A systematic review and meta-analysis

BACKGROUND

This systematic review and meta-analysis aims to explore in heart failure (HF) patients with reduced ejection fraction (EF) undergoing exercise-based cardiac rehabilitation the following: 1) the comparison of temporal changes between peak oxygen uptake (VO2peak) and first ventilatory threshold (VO2VT1), 2) the association of VO2peak and VO2VT1 changes with physiological factors, and 3) the differential effects of continuous aerobic exercise (CAE) and interval training (IT) on VO2peak and VO2VT1.

METHODS

A systematic literature search was conducted in PubMed, CENTRAL, and Scopus. Inclusion criteria were 1) original research articles using exercise-based cardiac rehabilitation, 2) stable HF patients with reduced EF, 3) available values of VO2peak and VO2VT1 (in mL/kg/min) both at baseline and after exercise training with comparison between these time points.

RESULTS

Among the 30 eligible trials, 24 used CAE, 5 IT, and one CAE and IT. Multivariable meta-regression with duration of exercise training and percentage of males as independent variables and the change in VO2peak as a dependent variable showed that the change in VO2peak was negatively associated with duration of exercise training (coefficient=-0.061, p=0.027), implying the possible existence of a waning effect of exercise training on VO2peak in the long term. Multivariable meta-regression demonstrated that both age (coefficient=-0.140, p<0.001) and EF (coefficient=-0.149, p<0.001) could predict the change in VO2VT1, whereas only age (coefficient=-0.095, p=0.022), but not EF (coefficient = 0.082, p = 0.100), could predict the change in VO2peak. The posttraining peak respiratory exchange ratio, as an index of maximum effort during exercise testing, correlated positively with the change in VO2peak (coefficient=-0.021, p=0.044). The exercise-induced changes of VO2peak (p = 0.438) and VO2VT1 (p = 0.474) did not differ between CAE and IT groups.

CONCLUSIONS

Improvement of endurance capacity during cardiac rehabilitation may be detected more accurately with the assessment of VO2VT1 rather than VO2peak.

Electromyogram Power Spectrum and Cardiac Function Changes After Combined Aerobic Interval Training and Inspiratory Muscle Training in Chronic Heart Failure Patients

Exercise intolerance and dyspnea are the major symptoms of patients with chronic heart failure (CHF) and are associated with a poor quality of life. In addition to impaired central hemodynamics, symptoms may be attributed to changes in peripheral skeletal muscles. This study aimed to evaluate the effects of aerobic interval training (AIT) combined with inspiratory muscle training (IMT) on cardiac and skeletal muscle function and on functional capacity and dyspnea in patients with CHF and inspiratory muscle weakness.Left ventricle ejection fraction was improved significantly after AIT and AIT & IMT with a high percentage of amelioration (17%, P < 0.042) in the combined group compared to the control group. Therefore, we showed a significant improvement in maximal voluntary isometric force, isometric endurance time, root mean square, and frequency median in both strength and endurance manipulations in the aerobic and combined group; however, the improvement was superior in the combined group compared to the control group. Significant amelioration was proved in functional capacity and dyspnea after all types of training but was performed at 18% higher in 6 minutes' walk test and 43% lower in dyspnea for the combined group compared to the control group.Combining AIT to IMT had optimized exercise training benefits in reversing the cardiac remodeling process and improving skeletal muscle function, functional capacity, and dyspnea in patients with CHF.

Inspiratory Muscle Strength in Chagas Cardiomyopathy: A Systematic Scoping Review

The increase in inflammatory markers associated with persistent chronic fibrosing myocarditis, a characteristic of chronic Chagas disease, can result in a reduction in inspiratory muscle strength (IMS) in Chagas cardiomyopathy (CC). However, literature in this field is still scarce. This review aimed to map and summarize the evidence regarding IMS in patients with CC. The inclusion criteria included reports with adult participants with a CC diagnosis, with or without heart failure (HF). The core concept examined was the maximum inspiratory pressure evaluated in the untrained and trained groups in the pre-training period. The context was open, including but not limited to hospitals and health centers. Two authors independently identified eligible studies and extracted the data. Descriptive synthesis was used as the primary strategy for analyzing the results. Nine studies (five clinical trials, three cross-sectional, and one cohort) were included. The CC classification differed among the studies, with no mention of HF in five and no CC staging specification in six. IMS was assessed using a manovacuometer, and only six studies analyzed and interpreted the data concerning the predicted values. The CC population with HF appeared to have impaired IMS. All studies involved only Brazilian volunteers. In conclusion, randomized clinical trials evaluating IMS and the effects of inspiratory muscle training need to be conducted to better understand the prevalence and risk of inspiratory muscle weakness in the CC population, as well as the effects of training. Such studies should be conducted at different stages of CC in different populations and countries.

Breathing pattern and pulmonary gas exchange in elderly patients with and without left ventricular dysfunction-modification with exercise-based cardiac rehabilitation and prognostic value

Background

Inefficient ventilation is an established prognostic marker in patients with heart failure. It is not known whether inefficient ventilation is also linked to poor prognosis in patients with left ventricular dysfunction (LVD) but without overt heart failure.

Objectives

To investigate whether inefficient ventilation in elderly patients with LVD is more common than in patients without LVD, whether it improves with exercise-based cardiac rehabilitation (exCR), and whether it is associated with major adverse cardiovascular events (MACE).

Methods

In this large multicentre observational longitudinal study, patients aged ≥65 years with acute or chronic coronary syndromes (ACS, CCS) without cardiac surgery who participated in a study on the effectiveness of exCR in seven European countries were included. Cardiopulmonary exercise testing (CPET) was performed before, at the termination of exCR, and at 12 months follow-up. Ventilation (VE), breathing frequency (BF), tidal volume (VT), and end-expiratory carbon dioxide pressure (PETCO2) were measured at rest, at the first ventilatory threshold, and at peak exercise. Ventilatory parameters were compared between patients with and without LVD (based on cardio-echography) and related to MACE at 12 month follow-up.

Results

In 818 patients, age was 72.5 ± 5.4 years, 21.9% were women, 79.8% had ACS, and 151 (18%) had LVD. Compared to noLVD, in LVD resting VE was increased by 8%, resting BF by 6%, peak VE, peak VT, and peak PETCO2 reduced by 6%, 8%, and 5%, respectively, and VE/VCO2 slope increased by 11%. From before to after exCR, resting VE decreased and peak PETCO2 increased significantly more in patients with compared to without LVD. In LVD, higher resting BF, higher nadir VE/VCO2, and lower peak PETCO2 at baseline were associated with MACE.

Conclusions

Similarly to patients with HF, in elderly patients with ischemic LVD, inefficient resting and exercise ventilation was associated with worse outcomes, and ExCR alleviated abnormal breathing patterns and gas exchange parameters.

Effects of different exercise modalities on inhibiting left ventricular pathological remodeling in patients with heart failure with reduced ejection fraction: A systematic review and network meta-analysis

AIMS

To evaluate the effects of different exercise training modalities on inhibiting the left ventricular pathological remodeling in patients with heart failure with reduced ejection fraction (HFrEF) and screen out the optimal exercise modality.

METHODS

We performed a network meta-analysis based on the Frequentist model. Random-effect meta-analyses were used to estimate mean differences (MD) and 95 % confidence intervals.

KEY FINDINGS

25 randomized controlled trials (1284 patients) were enrolled in this study. Results revealed that: high-intensity interval training had the best effect in improving left ventricular ejection fraction (p-score = 0.93, MD: 6.44 (3.61 to 9.28)), reducing left ventricular end-diastolic diameter (p-score = 0.97, MD: -6.73 (-10.27 to -3.19)) and left ventricular end-systolic diameter (p-score = 0.97, MD: -9.33 (-14.90 to -3.76)). Combined aerobic training with resistance training and inspiratory muscle training had the best effect in improving maximal oxygen consumption (p-score = 0.90, MD: 5.19 (3.12 to 7.25)).

SIGNIFICANCE

Current evidence revealed that exercise training could effectively inhibit left ventricular pathological remodeling in patients with HFrEF. For efficacy, high-intensity interval training may have greater potential.

Exercise Mode in Heart Failure: A Systematic Review and Meta-Analysis

BACKGROUND

Optimising exercise prescription in heart failure (HF) with a preserved (HFpEF) or reduced (HFrEF) ejection fraction is clinically important. As such, the aim of this meta-analysis was to compare traditional moderate intensity training (MIT) against combined aerobic and resistance training (CT) and high-intensity interval training (HIIT) for improving aerobic capacity (VO₂), as well as other clinically relevant parameters.

METHODS

A comprehensive systematic search was performed to identify randomised controlled trials published between 1990 and May 2021. Research trials reporting the effects of MIT against CT or HIIT on peak VO₂ in HFpEF or HFrEF were considered. Left-ventricular ejection fraction (LVEF) and various markers of diastolic function were also analysed.

RESULTS

Seventeen studies were included in the final analysis, 4 of which compared MIT against CT and 13 compared MIT against HIIT. There were no significant differences between MIT and CT for peak VO₂ (weighted mean difference [WMD]: 0.521 ml min^-1 kg^-1, [95% CI] =  - 0.7 to 1.8, P_fixed = 0.412) or LVEF (WMD: - 1.129%, [95% CI] =  - 3.8 to 1.5, P_fixed = 0.408). However, HIIT was significantly more effective than MIT at improving peak VO₂ (WMD: 1.62 ml min^-1 kg^-1, [95% CI] = 0.6-2.6, P_random = 0.002) and LVEF (WMD: 3.24%, [95% CI] = 1.7-4.8, P_random < 0.001) in HF patients. When dichotomized by HF phenotype, HIIT remained significantly more effective than MIT in all analyses except for peak VO₂ in HFpEF.

CONCLUSIONS

HIIT is significantly more effective than MIT for improving peak VO₂ and LVEF in HF patients. With the exception of peak VO₂ in HFpEF, these findings remain consistent in both phenotypes. Separately, there is no difference in peak VO₂ and LVEF change following MIT or CT, suggesting that the addition of resistance exercise does not inhibit aerobic adaptations in HF.

Impact of concurrent training versus aerobic or resistance training on cardiorespiratory fitness and muscular strength in middle-aged to older adults: A systematic review and meta-analysis

The effects of aerobic training (AT) on cardiorespiratory fitness (CRF), and resistance training (RT) on muscular strength, are well known in older adults. However, less is known about the potential additive benefits of concurrent training (CT) versus AT or RT alone in this population. We conducted a systematic review and meta-analysis to investigate the effects of CT, versus AT or RT, on CRF and muscular strength in middle-aged to older adults. PubMed and Web of Science were searched through October 2021 to identify randomized trials evaluating CT versus AT and/or RT in middle-aged and older adults (>50 yrs). Studies were included that measured CRF, using maximal or peak oxygen uptake (VO_2max/peak); and/or lower- and upper-body muscular strength measured using 1-repetition maximum (1RM) to 10RM tests during isoinertial contractions, or peak torque during isometric dynamometry or isokinetic dynamometry at 30 to 60°/s. Standardized mean differences (SMD) and 95% confidence intervals (95% CIs) were determined using random or fixed effects models. Forty-nine studies involving 2,587 middle-aged to older participants with mean ages ranging from 55 to 88 years, were included in the meta-analysis. Results indicated that CT effectively increased VO_2max/peak (SMD: 0.77, p = 0.005, 12 intervention arms) when compared to RT. In addition, CT effectively increased lower- (SMD: 0.60, p = 0.001, 43 intervention arms) and upper-body (SMD: 0.57, p = 0.001, 28 intervention arms) muscular strength when compared to AT. However, there were no differences in VO_2max/peak (SMD: 0.09, p = 0.09, 33 intervention arms) between CT and AT, or in lower-body (SMD: 0.07, p = 0.48, 21 intervention arms) and upper-body (SMD: -0.07, p = 0.38, 17 intervention arms) muscular strength between CT and RT. Overall, CT was shown to be effective for increasing CRF and muscular strength in middle-aged to older adults and there was no negative effect on the magnitude of changes in these outcomes compared to either AT or RT alone. These results suggested that CT should be considered a viable strategy to improvement of CRF and muscular strength with aging.

[Effect of center-based or home-based resistance training on muscle strength and VO2 peak in patients with Heart Failure: A systematic review and meta-analysis]

OBJECTIVE

To analyze the components of resistance training (RT) exercises and evaluate the effects of RT on improving muscle strength and oxygen consumption (VO₂) peak based on either center-based rehabilitation or home-based rehabilitation in patients with heart failure with reduced ejection fraction (HFrEF).

METHODS

According to the PRISMA guidelines, articles were searched through five databases, including Embase, MEDLINE, CINAHL, PEDro and Cochrane. RevMan 5.3 software was used to perform the meta-analysis.

RESULTS

Nine randomized controlled trial studies met the study criteria, including a total of 299 respondents. In the center-based respondents (n = 81 for intervention group vs. n = 81 for control group), RT resulted in significant effects on both muscle strength of lower extremity (SDM = 1.46, 95% CI = 0.41-2.50, n = 151) and upper extremity (SDM = 0.46, 95% CI = 0.05-0.87, n = 97) and VO₂ peak (MD = 1.45 ml/kg/min, 95% CI = 0.01-2.89, n = 114). In the home-based respondents (n = 71 for intervention group vs. n = 66 for control group), RT resulted in significant effects on muscle strength of both lower extremity (SDM = 0.58, 95% CI: 0.20-0.97, n = 113) and upper extremity (SDM = 0.84, 95% CI: 0.24-1.44, n = 47) and VO₂ peak (MD = 5.43 ml/kg/min, 95% CI: 0.23-10.62, n = 89).

CONCLUSION

The RT exercise could increase muscle strength and VO₂ peak at either center-based or home-based rehabilitation and should be considered as a part of the care of patients with HFrEF.

A randomized controlled trial of high-intensity interval training and inspiratory muscle training for chronic heart failure patients with inspiratory muscle weakness

OBJECTIVES

Chronic heart failure is a major public health problem in which supervised exercise programs are recommended as part of non-pharmacological management. There are various reports of the success of high-intensity aerobic interval training (HI-AIT) and inspiratory muscle training (IMT) in the management of chronic heart failure patients. This study tested the hypothesis that the combination of HI-AIT and IMT could result in additional benefits over the IMT and the HI-AIT alone in terms of inspiratory muscle function, exercise capacity, and quality of life in patients with chronic heart failure and inspiratory muscle weakness.

METHODS

Forty patients with ejection fraction ≤45% and inspiratory muscle weakness described by maximal inspiratory pressure <70% predicted, underwent three exercise training sessions per week for 12 weeks. Patients were randomly allocated to one of four groups: the HI-AIT group, the IMT group, the combined (HI-AIT & IMT) group, and the control group. Before and after completing their training period, all patients underwent different tests that are mentioned above.

RESULTS

No changes were detected in the control group. However, the combined group, when compared to HI-AIT and IMT groups, respectively, resulted in additional significant improvement in maximal inspiratory training (62%, 24%, 25%), exercise time (62%, 29%, 12%), the 6-minute walk test (23%, 15%, 18%), and the Minnesota Living with Heart Failure Questionnaire (56%, 47%, 36%).

CONCLUSION

In patients with chronic heart failure and inspiratory muscle weakness, the combination of the HI-AIT and the IMT resulted in additional benefits in respiratory muscle function, exercise performance, and quality of life compared to that of HI-AIT or IMT alone.Trial Registration number: NCT03538249.

Inspiratory muscle weakness in cardiovascular diseases: Implications for cardiac rehabilitation

Exercise limitation is a cardinal manifestation of many cardiovascular diseases (CVD) and is associated with poor prognosis. It is increasingly well understood that exercise-based cardiac rehabilitation (CR) is an intervention that portends favorable clinical outcomes, including improvements in exercise capacity. The etiology of exercise limitation in CVD is multifactorial but is typically governed by terminal sensations of pain, fatigue, and/or breathlessness. A known but perhaps underestimated complication of CVD that contributes to breathlessness and exercise intolerance in such patients is inspiratory muscle dysfunction. For example, inspiratory muscle dysfunction, which encompasses a loss in muscle mass and/or pressure generating capacity, occurs in up to ~40% of patients with chronic heart failure and is associated with breathlessness, exertional intolerance, and worse survival in this patient population. In this review, we define inspiratory muscle weakness, detail its prevalence in a range of CVDs, and discuss how inspiratory weakness impacts physiological function and clinical outcomes in patients with CVD often referred to CR. We also evaluate the available evidence addressing the effects of exercise-based CR with and without concurrent specific inspiratory muscle training (IMT) on inspiratory muscle function, general physiological function, and clinical outcomes in patients with CVD. Finally, we consider whether the assessment of global respiratory muscle function should become standard as part of the patient intake assessment for phase II CR programs, giving practical guidance on the implementation of such measures as well as IMT as part of phase II CR.

Application of Inspiratory Muscle Training to Improve Physical Tolerance in Older Patients with Ischemic Heart Failure

Regardless of the management regime for heart failure (HF), there is strong evidence supporting the early implementation of exercise-based cardiac rehabilitation (CR). Respiratory therapy is considered to be an integral part of such secondary prevention protocols. The aim of the study was to evaluate the effect of inspiratory muscle training (IMT) on exercise tolerance and the functional parameters of the respiratory system in patients with heart failure involved in cardiac rehabilitation. The study included 90 patients with HF who took part in the second-stage 8-week cycle of cardiac rehabilitation (CR). They were randomly divided into three groups: Group I underwent CR and IMT; Group II only CR; and patients in Group III underwent only the IMT. Before and after the 8-week cycle, participants were assessed for exercise tolerance and the functional parameters of respiratory muscle strength. Significant statistical improvement concerned the majority of the hemodynamic parameters, lung function parameters, and respiratory muscle strength in the first group. Moreover, the enhancement in the exercise tolerance in the CR + IMT group was accompanied by a negligible change in the HR_peak. The results confirm that the addition of IMT to the standard rehabilitation process of patients with heart failure can increase the therapeutic effect while influencing some of the parameters measured by exercise electrocardiography and respiratory function.

A systematic review of rehabilitation in chronic heart failure: evaluating the reporting of exercise interventions

A large body of research supports the use of exercise to improve symptoms, quality of life, and physical function in patients with chronic heart failure. Previous reviews have focused on reporting outcomes of exercise interventions such as cardiorespiratory fitness. However, none have critically examined exercise prescription. The aim of this review was to evaluate the reporting and application of exercise principles in randomised control trials of exercise training in patients with chronic heart failure. A systematic review of exercise intervention RCTs in patients with CHF, using the Consensus on Exercise Reporting Template (CERT), was undertaken. The Ovid Medline/PubMed, Embase, Scopus/Web of Science, and Cochrane Library and Health Technology Assessment Databases were searched from 2000 to June 2020. Prospective RCTs in which patients with CHF were randomized to a structured exercise programme were included. No limits were placed on the type or duration of exercise structured exercise programme or type of CHF (i.e. preserved or reduced ejection fraction). We included 143 studies, comprising of 181 different exercise interventions. The mean CERT score was 10 out of 19, with no study achieving a score of 19. Primarily, details were missing regarding motivational strategies, home-based exercise components, and adherence/fidelity to the intervention. Exercise intensity was the most common principle of exercise prescription missing from intervention reporting. There was no improvement in the reporting of exercise interventions with time (R²  = 0.003). Most RCTs of exercise training in CHF are reported with insufficient detail to allow for replication, limiting the translation of evidence to clinical practice. We encourage authors to provide adequate details when reporting future interventions. Where journal word counts are restrictive, we recommend using supplementary material or publishing trial protocols prior to beginning the study.

Effect of center-based or home-based resistance training on muscle strength and VO2 peak in patients with HFrEF: A systematic review and meta-analysis

OBJECTIVE

To analyze the components of resistance training (RT) exercises and evaluate the effects of RT on improving muscle strength and oxygen consumption (VO2) peak based on either center-based rehabilitation or home-based rehabilitation in patients with heart failure with reduced ejection fraction (HFrEF).

METHODS

According to the PRISMA guidelines, articles were searched through five databases, including Embase, MEDLINE, CINAHL, PEDro and Cochrane. RevMan 5.3 software was used to perform the meta-analysis.

RESULTS

Nine randomized controlled trial studies met the study criteria, including a total of 299 respondents. In the center-based respondents (n=81 for intervention group vs. n=81 for control group), RT resulted in significant effects on both muscle strength of lower extremity (SDM=1.46, 95% CI=0.41-2.50, n=151) and upper extremity (SDM=0.46, 95% CI=0.05-0.87, n=97) and VO2 peak (MD=1.45ml/kg/min, 95% CI=0.01-2.89, n=114). In the home-based respondents (n=71 for intervention group vs. n=66 for control group), RT resulted in significant effects on muscle strength of both lower extremity (SDM=0.58, 95% CI: 0.20-0.97, n=113) and upper extremity (SDM=0.84, 95% CI: 0.24-1.44, n=47) and VO2 peak (MD=5.43ml/kg/min, 95% CI: 0.23-10.62, n=89).

CONCLUSION

The RT exercise could increase muscle strength and VO2 peak at either center-based or home-based rehabilitation and should be considered as a part of the care of patients with HFrEF.

Selection of the optimal respiratory muscle training mode in patients with class II-III chronic heart failure

Aim To study the effect of various types of respiratory muscle training (RMT) in patients with functional class (FC) II-III chronic heart failure (CHF) and more than 70% preserved diaphragm muscle mass.Material and methods 53 patients (28 men and 25 women) aged 50-75 years with NYHA FC II-III ischemic heart disease (IHD) and arterial hypertension with more than 70% preserved diaphragm muscle mass of &gt;70% were randomized to one of four RMT types: static loads, dynamic loads, their combination, and breathing without applied resistance as a control. Peak oxygen consumption (VO2 peak) and maximum inspiratory pressure (MIP) were evaluated at baseline and in 6 months.Results All study groups showed significant improvement of physical endurance indexes compared to baseline values (р&lt;0.05). In pairwise comparison, the groups significantly differed (р&lt;0.01). The greatest improvement was observed for patients of dynamic and combined training groups. Furthermore, in the combined training group, results were significantly higher than in the group of isolated dynamic loads. The most significant (р &lt;0.01), positive changes in the force of inspiratory muscles were observed in groups of dynamic and combined trainings with the best results displayed by patients of the combined training group.Conclusion With preserving more than 70 % of diaphragm muscle tissue (as determined by MIP &gt;60 cm H2O), a combination of static and dynamic RMT is most effective for patients with FC II-III CHF.

Cardiac Rehabilitation for Patients With Heart Failure: JACC Expert Panel

Cardiac rehabilitation is defined as a multidisciplinary program that includes exercise training, cardiac risk factor modification, psychosocial assessment, and outcomes assessment. Exercise training and other components of cardiac rehabilitation (CR) are safe and beneficial and result in significant improvements in quality of life, functional capacity, exercise performance, and heart failure (HF)-related hospitalizations in patients with HF. Despite outcome benefits, cost-effectiveness, and strong practice guideline recommendations, CR remains underused. Clinicians, health care leaders, and payers should prioritize incorporating CR as part of the standard of care for patients with HF.

Unraveling the Role of Respiratory Muscle Metaboloreceptors under Inspiratory Training in Patients with Heart Failure

Exercise intolerance may be considered a hallmark in patients who suffer from heart failure (HF) syndrome. Currently, there is enough scientific evidence regarding functional and structural deterioration of skeletal musculature in these patients. It is worth noting that muscle weakness appears first in the respiratory muscles and then in the musculature of the limbs, which may be considered one of the main causes of exercise intolerance. Functional deterioration and associated atrophy of these respiratory muscles are related to an increased muscle metaboreflex leading to sympathetic–adrenal system hyperactivity and increased pulmonary ventilation. This issue contributes to increased dyspnea and/or fatigue and decreased aerobic function. Consequently, respiratory muscle weakness produces exercise limitations in these patients. In the present review, the key role that respiratory muscle metaboloreceptors play in exercise intolerance is accurately addressed in patients who suffer from HF. In conclusion, currently available scientific evidence seems to affirm that excessive metaboreflex activity of respiratory musculature under HF is the main cause of exercise intolerance and sympathetic–adrenal system hyperactivity. Inspiratory muscle training seems to be a useful personalized medicine intervention to reduce respiratory muscle metaboreflex in order to increase patients’ exercise tolerance under HF condition.

Combined aerobic/resistance/inspiratory muscle training as the 'optimum' exercise programme for patients with chronic heart failure: ARISTOS-HF randomized clinical trial

AIMS

An 'optimum' universally agreed exercise programme for heart failure (HF) patients has not been found. ARISTOS-HF randomized clinical trial evaluates whether combined aerobic training (AT)/resistance training (RT)/inspiratory muscle training (IMT) (ARIS) is superior to AT/RT, AT/IMT or AT in improving aerobic capacity, left ventricular dimensions, and secondary functional outcomes.

METHODS AND RESULTS

Eighty-eight patients of New York Heart Association II-III, left ventricular ejection fraction  ≤ 35% were randomized to an ARIS, AT/RT, AT/IMT, or AT group, exercising 3 times/week, 180 min/week for 12 weeks. Pre- and post-training, peakVO2 was evaluated with cardiopulmonary exercise testing, left ventricular dimensions using echocardiography, walking distance with the 6-min walk test (6MWT), quality of life by the Minnesota Living with HF Questionnaire (MLwHFQ), while a programme preference survey (PPS) was used. Seventy-four patients of [mean 95% (confidence interval, CI)] age 66.1 (64.3-67.9) years and peakVO2 17.3 (16.4-18.2) mL/kg/min were finally analysed. Between-group analysis showed a trend for increased peakVO2 (mL/kg/min) [mean contrasts (95% CI)] in the ARIS group [ARIS vs. AT/RT 1.71 (0.163-3.25)(.), vs. AT/IMT 1.50 (0.0152-2.99)(.), vs. AT 1.38 (-0.142 to 2.9)(.)], additional benefits in circulatory power (mL/kg/min⋅mmHg) [ARIS vs. AT/RT 376 (60.7-690)*, vs. AT/IMT 423 (121-725)*, vs. AT 345 (35.4-656)*], left ventricular end-systolic diameter (mm) [ARIS vs. AT/RT -2.11 (-3.65 to (-0.561))*, vs. AT -2.47 (-4.01 to (-0.929))**], 6MWT (m) [ARIS vs. AT/IMT 45.6 (18.3-72.9)**, vs. AT 55.2 (27.6-82.7)****], MLwHFQ [ARIS vs. AT/RT -7.79 (-11 to (-4.62))****, vs. AT -8.96 (-12.1 to (-5.84))****], and in PPS score [mean (95% CI)] [ARIS, 4.8 (4.7-5) vs. AT, 4.4 (4.2-4.7)*] [(.) P ≤ 0.1; *P ≤ 0.05; **P ≤ 0.01; ***P ≤ 0.001; ****P ≤ 0.0001].

CONCLUSION

ARISTOS-HF trial recommends exercise training for 180 min/week and supports the prescription of the ARIS training regime for HF patients (Clinical Trial Registration: http://www.clinicaltrials.gov. ARISTOS-HF Clinical Trial number, NCT03013270).

The Effects of Aerobic Exercise on N-terminal Pro-B-type Natriuretic Peptide and Cardiopulmonary Function in Patients With Heart Failure: A Meta-Analysis of Randomised Clinical Trials

BACKGROUND

Aerobic exercise (AEx) improves outcomes in heart failure (HF). N-terminal pro B-type natriuretic peptide (NT-pro-BNP) is a prognosticator in HF. There are few data on the association of AEx, NT-pro-BNP, and cardiopulmonary function; hence, robust evidence is needed. The aim of this study was to measure the effects of AEx on NT-pro-BNP levels and cardiopulmonary function in HF.

METHOD

Databases (Pubmed, EMBASE, Medline, Cochrane Central Registry, and Scopus) were systematically searched for randomised controlled trials (RCTs) that assessed the association of AEx with NT-pro-BNP and cardiopulmonary function (VE/VCO₂ slope, peak VO₂, maximal workload, and left ventricular ejection fraction [LVEF]) in HF. RevMan 5.3 (The Nordic Cochrane Centre, The Cochrane Collaboration, Copenhagen, 2014) was used to produce forest plots, and the random-effect model was applied with the effects measure of weighted mean differences (WMD) and 95% confidence interval (CI).

RESULTS

Thirteen (13) RCTs recruited 1,503 patients and 1,494 controls. Aerobic exercise was significant in lowering NT-pro-BNP (pg/mL) compared with control group (WMD=-741.69, 95% CI -993.10 to -490.27 [p<0.00001; I²=63%]). VE/VCO₂ slope was also significantly reduced (WMD=-3.57, 95% CI -6.48 to -0.67 [p=0.02; I²=97%]). Peak VO₂ (mL/kg/min) significantly improved (WMD=3.68, 95% CI 2.39-4.96 [p<0.00001; I²=96%]). Maximal workload (watt) significantly increased following AEx (WMD=22.80, 95% CI 18.44-27.17 [p<0.00001; I²=78%]). Furthermore, there was a significant enhancement of LVEF (%) in the AEx group (WMD=2.42, 95% CI 0.64-4.19 [p=0.008; I²=71%]).

CONCLUSIONS

Aerobic exercise improves the NT-pro-BNP, ventilatory efficiency, aerobic capacity, maximal workload, and the left ventricular function in patients with HF.

Inspiratory Muscle Training in Patients with Heart Failure

Background: Prior systematic reviews and meta-analysis addressed that inspiratory muscle training (IMT) improved inspiratory muscle weakness, cardiorespiratory fitness and quality of life similar to conventional exercise training as a first alternative in deconditioned patients with heart failure (HF) lead to a better adaptation to posterior exercise training. The heterogeneity and variability in a wide range of new studies about this topic led to the necessity of an updated and comprehensive narrative review. The present review aimed to analyze and update the most relevant studies about IMT in patients who suffer from HF. Methods: A narrative review was carried out about IMT in HF patients including 26 experimental studies divided into 21 clinical trials and 5 quasi-experimental studies identified through database searching in PubMed, Cochrane and PEDro. Results: There is enough evidence to state that IMT produces improvements in functional capacity of patients with HF. Nevertheless, there is not enough evidence to support that IMT could improve cardiovascular parameters, blood biomarkers or quality of life in these patients. Conclusions: Thus, IMT may be recommended to improve functional capacity in patients who suffer from HF; nevertheless, more evidence is needed regarding cardiovascular parameters, biomarkers and quality of life. Furthermore, mortality or HF hospitalization was not evaluated and most studies were not longer than 3 months. According to IMT protocols and study designs heterogeneity and mid-term follow-up, further investigations through high-quality long-term randomized clinical trials should be performed to achieve systematic reviews and meta-analysis to support strong evidence for IMT in HF patients.

Cardiopulmonary exercise capacity and quality of life of patients with heart failure undergoing a functional training program: study protocol for a randomized clinical trial

BACKGROUND

Exercise intolerance is a common finding in heart failure that generates a vicious cycle in which the individual starts to limit his activities even more due to progressive fatigue. Regular physical exercise can increase the cardiopulmonary exercise capacity of these individuals. A new approach to physical exercise, known as functional training, could improve the oxygen consumption and quality of life of patients with heart failure; however, there is no information about the effect of this modality of exercise in this patient population. This randomized trial will compare the effects of 36 sessions of functional training versus strength training in heart failure patients.

METHODS

This randomized parallel-design examiner-blinded clinical trial includes individuals of both sexes aged ≥40 years receiving regular follow-up at a single academic hospital. Subjects will be randomly allocated to an intervention group (for 12-week functional training) or an active comparator group (for 12-week strength training). The primary outcomes will be the difference from baseline to the 3-month time point in peak oxygen consumption on cardiopulmonary exercise testing and quality of life assessed by the Minnesota Living with Heart Failure Questionnaire. Secondary outcome measures will include functionality assessed by the Duke Activity Status Index and gait speed test; peripheral and inspiratory muscular strength, assessed by hand grip and manovacuometry testing, respectively; endothelial function by brachial artery flow-mediated dilation; lean body mass by arm muscle circumference; and participant adherence to the exercise programs classified as a percentage of the prescribed exercise dose.

DISCUSSION

The functional training program aims to improve the functional capacity of the individual using exercises that relate to his specific physical activity transferring gains effectively to one's daily life. In this context, we believe that that functional training can increase the cardiopulmonary exercise capacity and quality of life of patients with heart failure. The trial has been recruiting patients since October 2017.

TRIAL REGISTRATION

NCT03321682. Registered on October 26, 2017.

Physical Therapist Clinical Practice Guideline for the Management of Individuals With Heart Failure

The American Physical Therapy Association (APTA), in conjunction with the Cardiovascular and Pulmonary Section of APTA, have commissioned the development of this clinical practice guideline to assist physical therapists in their clinical decision making when managing patients with heart failure. Physical therapists treat patients with varying degrees of impairments and limitations in activity and participation associated with heart failure pathology across the continuum of care. This document will guide physical therapist practice in the examination and treatment of patients with a known diagnosis of heart failure. The development of this clinical practice guideline followed a structured process and resulted in 9 key action statements to guide physical therapist practice. The level and quality of available evidence were graded based on specific criteria to determine the strength of each action statement. Clinical algorithms were developed to guide the physical therapist in appropriate clinical decision making. Physical therapists are encouraged to work collaboratively with other members of the health care team in implementing these action statements to improve the activity, participation, and quality of life in individuals with heart failure and reduce the incidence of heart failure-related re-admissions.

Respiratory training interventions improve health status of heart failure patients: A systematic review and network meta-analysis of randomized controlled trials

BACKGROUND

Prior studies indicate that doing breathing exercises improves physical performance and quality of life (QoL) in heart failure patients. However, these effects remain unclear and contradictory.

AIM

To determine the effects of machine-assisted and non-machine-assisted respiratory training on physical performance and QoL in heart failure patients.

METHODS

This was a systematic review and network meta-analysis study. A literature search of electronic databases was conducted for randomized controlled trials (RCTs) on heart failure. Respiratory training interventions were grouped as seven categories: IMT_Pn (inspiratory muscle training without pressure or < 10% maximal inspiratory pressure, MIP), IMT_Pl (inspiratory muscle training with low pressure, 10%-15% MIP), IMT_Pm (inspiratory muscle training with medium pressure, 30%-40% MIP), IMT_Ph (inspiratory muscle training with high pressure, 60% MIP or MIP plus aerobics), Aerobics (aerobic exercise or weight training), Qi_Ex (tai chi, yoga, and breathing exercise), and none. The four outcomes were heart rate, peak oxygen uptake (VO₂ peak), 6-min walking distance test (6MWT), and Minnesota Living with Heart Failure QoL. The random-effects model, side-splitting model, and the surface under the cumulative ranking curve (SUCRA) were used to test and analyze the data.

RESULTS

A total of 1499 subjects from 31 RCT studies were included. IMT_Ph had the highest effect sizes for VO₂ peak and 6MWT, IMT_Pm highest for QoL, and Qi_Ex highest for heart rate. Aerobics had the second highest for VO₂ peak, Qi_Ex second highest for 6MWT, and IMT_Ph second highest for heart rate and QoL.

CONCLUSION

This study supports that high- and medium-intensity machine-assisted training improves exercise capacity and QoL in hospital-based heart failure patients. After hospital discharge, non-machine-assisted training continuously improves cardiac function.

Exercise training in patients with a left ventricular assist device (Ex-VAD): rationale and design of a multicentre, prospective, assessor-blinded, randomized, controlled trial

AIMS

Left ventricular assist device (LVAD) therapy is a promising option for patients with advanced heart failure (HF), refractory to guideline-mandated medical treatment either as a bridge to heart transplantation or as lifelong therapy. Functional capacity improves after LVAD implantation but remains reduced in patients with long-term LVAD therapy. Exercise training (ET) improves functional capacity and quality of life (QoL) in HF and may provide incremental benefits in patients supported with LVAD therapy.

METHODS

The primary objective of Ex-VAD is to investigate whether a 12-week supervised ET can improve peak oxygen uptake (peakVO2 ) measured by cardiopulmonary exercise testing (CPET) on an ergometer. The study is powered to demonstrate a group difference of 3 mL/min/kg in peakVO2 at week 12, with a power of 0.9 and a standard deviation of 5 mL/min/kg. After baseline assessments to determine whether ET is safe, 66 patients at six trial sites with advanced HF and LVAD therapy will be randomized 2:1 to supervised ET or to the control arm of usual care alone. Patients randomized to ET will perform supervised aerobic endurance and resistance ET (three times/week) for 12 weeks. At baseline and during follow-up, anthropometry, CPET, echocardiography (at rest and exercise), and QoL evaluation will be performed. Blood samples will be collected to examine cardiac-specific relevant biomarkers. Overall physical activity, training sessions, and adherence will be monitored and documented throughout the study using accelerometers and patient diaries.

CONCLUSIONS

The Ex-VAD trial will assess the effects of a supervised ET programme on peakVO2 and QoL in patients with LVAD. As LVAD therapy moves from crisis support to ambulatory functional enhancement, this trial will provide a rationale to improve functional capacity and, in perspective, cardiovascular outcomes in LVAD-supported patients with advanced HF.

The effect of inspiratory muscle training on fatigue and dyspnea in patients with heart failure: A randomized, controlled trial

AIM

Fatigue and dyspnea are debilitating symptoms in patients with heart failure (HF). The purpose of this study was to evaluate the effects of inspiratory muscle training (IMT) on dyspnea, fatigue and the New York Heart Association (NYHA) functional classification in patients with HF.

METHODS

In this prospective, randomized, controlled trial, 84 patients with HF (NYHA classes II-III/IV) with a mean age of 56.62 ± 9.56 years were randomly assigned to a 6-week IMT (n = 42) or a sham IMT (n = 42) program. The IMT was performed at 40% of the maximal inspiratory pressure (MIP) in the IMT group and at 10% in the sham group. The main outcomes were assessed at baseline and after the intervention and included dyspnea severity scale (Modified Medical Research Council [MMRC], Fatigue Severity Scale [FSS] and the NYHA functional classification (based on the presenting symptoms).

RESULTS

The between-group analysis showed significant improvements in dyspnea, fatigue and the NYHA functional classification in the IMT group compared to the sham group (P < .05). The within-group analysis showed significant improvements in dyspnea (from 2.63 ± 0.79 to 1.38 ± 0.66, P < .001), fatigue (from 43.36 ± 8.5 to 28.95 ± 9.11, P < .001) and the NYHA functional classification (from 2.73 ± 0.5 to 2.1 ± 0.6, P = .001) in the IMT group, while fatigue and dyspnea increased significantly in the sham group.

CONCLUSIONS

The 6-week home-based IMT was found to be an effective and safe tool for reducing dyspnea and fatigue and improving the NYHA functional classification.

Resistance exercise enhances oxygen uptake without worsening cardiac function in patients with systolic heart failure: a systematic review and meta-analysis

Recent literature suggests that resistance training (RT) improves peak oxygen uptake ([Formula: see text] peak), similarly to aerobic exercise (AE) in patients with heart failure (HF), but its effect on cardiac remodeling is controversial. Thus, we examined the effects of RT and AE on [Formula: see text] peak and cardiac remodeling in patients with heart failure (HF) via a systematic review and meta-analysis. MEDLINE, EMBASE, Cochrane Library and CINAHL, AMEDEO and PEDro databases search were extracted study characteristics, exercise type, and ventricular outcomes. The main outcomes were [Formula: see text] peak (ml kg^-1 min^-1), LVEF (%) and LVEDV (mL). Fifty-nine RCTs were included. RT produced a greater increase in [Formula: see text] peak (3.57 ml kg^-1 min^-1, P < 0.00001, I ² = 0%) compared to AE (2.63 ml kg^-1 min^-1, P < 0.00001, I ² = 58%) while combined RT and AE produced a 2.48 ml kg^-1 min^-1 increase in [Formula: see text]; I ² = 69%) compared to control group. Comparison among the three forms of exercise revealed similar effects on [Formula: see text] peak (P = 0.84 and 1.00, respectively; I ² = 0%). AE was associated with a greater gain in LVEF (3.15%; P < 0.00001, I ² = 17%) compared to RT alone or combined exercise which produced similar gains compared to control groups. Subgroup analysis revealed that AE reduced LVEDV (- 10.21 ml; P = 0.007, I ² = 0%), while RT and combined RT and AE had no effect on LVEDV compared with control participants. RT results in a greater gain in [Formula: see text] peak, and induces no deleterious effects on cardiac function in HF patients.

Moderate-to-high intensity inspiratory muscle training improves the effects of combined training on exercise capacity in patients after coronary artery bypass graft surgery: A randomized clinical trial

BACKGROUND

The effects of adding moderate-to-high intensity inspiratory muscle training (IMT) to short-term aerobic and resistance exercise (combined training [CT]), after coronary artery bypass grafting (CABG) are not established. This study aimed to determine the effects of moderate-to-high intensity IMT + CT on exercise capacity, respiratory muscle strength, inspiratory muscle endurance, quality of life (QoL), and laboratory biomarkers in patients after CABG who were participants of a phase II cardiac rehabilitation program.

METHODS

Twenty-four patients were randomly assigned to either the IMT + CT group (n = 12), who performed moderate-to-high intensity IMT with CT or the sham-IMT + CT group (n = 12). Patients completed two sessions per week for 12 weeks. Each patient underwent a cardiopulmonary exercise test, six-minute walk test (6MWT), respiratory muscle strength and endurance evaluation, QoL questionnaire, and serum advanced oxidation protein products, ferric reducing antioxidant power [FRAP], nitrate/nitrate, and high-sensitivity C-reactive protein, before and after the 12-week intervention.

RESULTS

The IMT + CT group showed significantly greater improvements in peak oxygen uptake (1.3 mL∙kg^-1∙min^-1; 95% confidence interval [95% CI], 0.5 to 2.2), distance covered during the 6MWT (78.8 m; 95% CI, 28.1 to 129.5), maximal inspiratory pressure (23.0 cmH₂O; 95% CI, 9.3 to 36.7), QoL (-15.1 points; 95% CI, -26.9 to -3.3), and FRAP (83.7 μmol/L; 95% CI, 20.2 to 147.1) compared to the sham-IMT + CT group as a result of the intervention.

CONCLUSIONS

Short-term moderate-to-high intensity IMT with CT provided additional benefits in exercise capacity, inspiratory muscle strength, QoL, and antioxidant profile in patients after CABG. Trial Registration clinicaltrials.gov Identifier: NCT02885077.

The ‘aerobic/resistance/inspiratory muscle training hypothesis in heart failure’

Evidence from large multicentre exercise intervention trials in heart failure patients, investigating both moderate continuous aerobic training and high intensity interval training, indicates that the ‘crème de la crème’ exercise programme for this population remains to be found. The ‘aerobic/resistance/inspiratory (ARIS) muscle training hypothesis in heart failure’ is introduced, suggesting that combined ARIS muscle training may result in maximal exercise pathophysiological and functional benefits in heart failure patients. The hypothesis is based on the decoding of the ‘skeletal muscle hypothesis in heart failure’ and on revision of experimental evidence to date showing that exercise and functional intolerance in heart failure patients are associated not only with reduced muscle endurance, indication for aerobic training (AT), but also with reduced muscle strength and decreased inspiratory muscle function contributing to weakness, dyspnoea, fatigue and low aerobic capacity, forming the grounds for the addition of both resistance training (RT) and inspiratory muscle training (IMT) to AT. The hypothesis will be tested by comparing all potential exercise combinations, ARIS, AT/RT, AT/IMT, AT, evaluating both functional and cardiac indices in a large sample of heart failure patients of New York Heart Association class II–III and left ventricular ejection fraction ≤35% ad hoc by the multicentre randomized clinical trial, Aerobic Resistance, InSpiratory Training OutcomeS in Heart Failure (ARISTOS-HF trial).

Diaphragm abnormalities in heart failure and aging: mechanisms and integration of cardiovascular and respiratory pathophysiology

Inspiratory function is essential for alveolar ventilation and expulsive behaviors that promote airway clearance (e.g., coughing and sneezing). Current evidence demonstrates that inspiratory dysfunction occurs during healthy aging and is accentuated by chronic heart failure (CHF). This inspiratory dysfunction contributes to key aspects of CHF and aging cardiovascular and pulmonary pathophysiology including: (1) impaired airway clearance and predisposition to pneumonia; (2) inability to sustain ventilation during physical activity; (3) shallow breathing pattern that limits alveolar ventilation and gas exchange; and (4) sympathetic activation that causes cardiac arrhythmias and tissue vasoconstriction. The diaphragm is the primary inspiratory muscle; hence, its neuromuscular integrity is a main determinant of the adequacy of inspiratory function. Mechanistic work within animal and cellular models has revealed specific factors that may be responsible for diaphragm neuromuscular abnormalities in CHF and aging. These include phrenic nerve and neuromuscular junction alterations as well as intrinsic myocyte abnormalities, such as changes in the quantity and quality of contractile proteins, accelerated fiber atrophy, and shifts in fiber type distribution. CHF, aging, or CHF in the presence of aging disturbs the dynamics of circulating factors (e.g., cytokines and angiotensin II) and cell signaling involving sphingolipids, reactive oxygen species, and proteolytic pathways, thus leading to the previously listed abnormalities. Exercise-based rehabilitation combined with pharmacological therapies targeting the pathways reviewed herein hold promise to treat diaphragm abnormalities and inspiratory muscle dysfunction in CHF and aging.

Combined Exercise and Inspiratory Muscle Training in Patients With Heart Failure: A SYSTEMATIC REVIEW AND META-ANALYSIS

PURPOSE

Studies have reported the benefits of exercise and inspiratory muscle training (IMT) in patients with heart failure (HF); however, there is no meta-analysis on the effects of the combination of exercise and IMT in patients with HF. The objective of this study was to determine whether combined exercise/IMT was more effective than conventional exercise on exercise capacity, respiratory muscle strength, and quality of life in patients with HF.

METHODS

This is a systematic review and meta-analysis. We searched MEDLINE, LILACS, CINAHL, EMBASE, PEDro, and the Cochrane Central Register of Controlled Trials (from the earliest date available to April 2015) for randomized controlled trials, examining effects of combined exercise/IMT versus conventional exercise on exercise capacity, respiratory muscle strength, and quality of life measurements in patients with HF. Two reviewers selected studies independently. Weighted mean differences and 95% CIs were calculated.

RESULTS

Three studies met the study criteria. Combined exercise/IMT resulted in improvement in maximal inspiratory pressure weighted mean differences (20.89 cm H2O; 95% CI, 14.0-27.78) and Minnesota Living with Heart Failure Questionnaire weighted mean differences (4.43; 95% CI, 0.72-8.14). Nonsignificant difference was observed in peak (Equation is included in full-text article.)O2 for participants in the combined exercise/IMT group compared with the conventional exercise group. No serious adverse events were reported.

CONCLUSIONS

Combined exercise/IMT may improve maximal inspiratory pressure and quality of life in patients with HF and should be considered for inclusion in cardiac rehabilitation programs.

Skeletal muscle aging: influence of oxidative stress and physical exercise

Skeletal muscle abnormalities are responsible for significant disability in the elderly. Sarcopenia is the main alteration occurring during senescence and a key public health issue as it predicts frailty, poor quality of life, and mortality. Several factors such as reduced physical activity, hormonal changes, insulin resistance, genetic susceptibility, appetite loss, and nutritional deficiencies are involved in the physiopathology of muscle changes. Sarcopenia is characterized by structural, biochemical, molecular and functional muscle changes. An imbalance between anabolic and catabolic intracellular signaling pathways and an increase in oxidative stress both play important roles in muscle abnormalities. Currently, despite the discovery of new targets and development of new drugs, nonpharmacological therapies such as physical exercise and nutritional support are considered the basis for prevention and treatment of age-associated muscle abnormalities. There has been an increase in information on signaling pathways beneficially modulated by exercise; nonetheless, studies are needed to establish the best type, intensity, and frequency of exercise to prevent or treat age-induced skeletal muscle alterations.

Feasibility of Using Accelerometer Measurements to Assess Habitual Physical Activity in Rural Heart Failure Patients

(1) Background: Physical inactivity is prevalent in rural heart failure (HF) patients. To evaluate the effectiveness of interventions aimed at improving physical activity (PA), we need an accurate, reliable PA assessment tool that is feasible and acceptable to HF patients. The purpose of this study was to examine the feasibility and reliability of using an accelerometer to assess HF patients' PA. (2) Method: A total of 100 HF patients discharged from a rural hospital participated in the study and wore an accelerometer at baseline, 3, and 6 months following discharge. (3) Result: The daily average wear time across all three time points was 15.7 (±3.3) h for weekdays, and 15.8 (±3.7) h for weekends. Approximately 50% of the participants adhered to the device wear protocol at baseline, 3, and 6 months. Factors related to wear time were also examined. Acceptable reliability assessed by intra-class correlation (ICC > 0.879) was found for daily activity calories, activity counts per minutes, and time spent on moderate or greater PA. (4) Conclusion: The present findings suggest that an accelerometer is a feasible and reliable measure of habitual PA in rural HF patients over time.

Is there any benefit using low-intensity inspiratory and peripheral muscle training in heart failure? A randomized clinical trial

BACKGROUND

Inspiratory and peripheral muscle training improves muscle strength, exercise tolerance, and quality of life in patients with chronic heart failure (HF). However, studies investigating different workloads for these exercise modalities are still lacking.

OBJECTIVE

To examine the effects of low and moderate intensities on muscle strength, functional capacity, and quality of life.

DESIGN

A randomized controlled trial.

METHODS

Thirty-five patients with stable HF (aged >18 years, NYHA II/III, LVEF <40%) were randomized to: non-exercise control group (n = 9), low-intensity training group (LIPRT, n = 13, 15% maximal inspiratory workload, and 0.5 kg of peripheral muscle workload) or moderate-intensity training group (MIPRT, n = 13, 30% maximal inspiratory workload and 50% of one maximum repetition of peripheral muscle workload). The outcomes were: respiratory and peripheral muscle strength, pulmonary function, exercise tolerance by the 6-minute walk test, symptoms based on the NYHA functional class, and quality of life using the Minnesota Living with Heart Failure Questionnaire.

RESULTS

All groups showed similar quality-of-life improvements. Low and moderate intensities training programs improved inspiratory muscle strength, peripheral muscle strength, and walking distance. However, only moderate intensity improved expiratory muscle strength and NYHA functional class in HF patients.

CONCLUSIONS

The low-intensity inspiratory and peripheral resistance muscle training improved inspiratory and peripheral muscle strength and walking distance, demonstrating that LIPRT is an efficient rehabilitation method for debilitated HF patients. In addition, the moderate-intensity resistance training also improved expiratory muscle strength and NYHA functional class in HF patients.

The Aetiology of Reduced Cardiorespiratory Fitness Among Adults with Severe Traumatic Brain Injury and the Relationship with Physical Activity: A Narrative Review

Reduced cardiorespiratory fitness or cardiorespiratory deconditioning is a secondary physical impairment commonly reported to affect people after traumatic brain injury (TBI), both in the short- and long-term. Eleven studies have measured peak oxygen uptake${\rm ({\dot V}O}_{{\rm 2peak}} )$to evaluate fitness in this population. The mean (SD)${\rm \dot VO}_{{\rm 2peak}}$from these studies was 27.2 (6.7) mL.kg−1·min−1, which is markedly below the average fitness level of age-matched healthy individuals. The aetiology of cardiorespiratory deconditioning has not been well evaluated among people with TBI; however, studies on prolonged bed rest and studies on the acute consequences of TBI inform our current understanding. The primary aim of this paper is to present a model to describe the physiological factors contributing to the development of cardiorespiratory deconditioning among people with severe TBI. We propose that both central and peripheral factors contribute to reduced fitness, and that these changes occur because of both the initial brain damage and trauma sustained and the prolonged and initially extreme physical inactivity that is commonly experienced after this type of injury. Reduced fitness can significantly affect the ability to return to pre-injury activities. Given that reintegration into the community is a key goal of rehabilitation among people with TBI, interventions that can prevent or reverse reduced fitness need to be implemented.

Breathing exercises and inspiratory muscle training in heart failure

Breathing exercises (BE) and inspiratory muscle training (IMT) have been demonstrated to improve ventilation and ventilation-to-perfusion matching, and to improve exercise, functional performance, and many pathophysiologic manifestations of heart failure (HF). This article provides an extensive review of BE and IMT in patients with HF and identifies several key areas in need of further investigation, including the role of expiratory muscle training, IMT targeted at various locations of inspiration (early, mid, or late inspiration), and alteration of the ratio of inspiratory time to total breath time, all of which have substantial potential to improve many pathophysiologic manifestations of HF.

Short-term inspiratory muscle training potentiates the benefits of aerobic and resistance training in patients undergoing CABG in phase II cardiac rehabilitation program

OBJECTIVE

To investigate the efficiency of short-term inspiratory muscle training program associated with combined aerobic and resistance exercise on respiratory muscle strength, functional capacity and quality of life in patients who underwent coronary artery bypass and are in the phase II cardiac rehabilitation program.

METHODS

A prospective, quasi-experimental study with 24 patients who underwent coronary artery bypass and were randomly assigned to two groups in the Phase II cardiac rehabilitation program: inspiratory muscle training program associated with combined training (aerobic and resistance) group (GCR + IMT, n=12) and combined training with respiratory exercises group (GCR, n=12), over a period of 12 weeks, with two sessions per week. Before and after intervention, the following measurements were obtained: maximal inspiratory and expiratory pressures (PImax and PEmax), peak oxygen consumption (peak VO2) and quality of life scores. Data were compared between pre- and post-intervention at baseline and the variation between the pre- and post-phase II cardiac rehabilitation program using the Student's t-test, except the categorical variables, which were compared using the Chi-square test. Values of P<0.05 were considered statistically significant.

RESULTS

Compared to GCR, the GCR + IMT group showed larger increments in PImax (P<0.001), PEmax (P<0.001), peak VO2 (P<0.001) and quality of life scores (P<0.001).

CONCLUSION

The present study demonstrated that the addition of inspiratory muscle training, even when applied for a short period, may potentiate the effects of combined aerobic and resistance training, becoming a simple and inexpensive strategy for patients who underwent coronary artery bypass and are in phase II cardiac rehabilitation.

Muscle wasting in ageing and chronic illness

PURPOSE

As life expectancy increases, muscle wasting is becoming a more and more important public health problem. This review summarizes the current knowledge of pathophysiological mechanisms underlying muscle loss in ageing and chronic diseases such as heart failure and discusses evolving interventional strategies.

RECENT FINDINGS

Loss of skeletal muscle mass and strength is a common phenomenon in a wide variety of disorders associated with ageing and morbidity-associated catabolic conditions such as chronic heart failure. Muscle wasting in ageing but otherwise healthy human beings is referred to as sarcopenia. Unlike cachexia in advanced stages of chronic heart failure, muscle wasting per se is not necessarily associated with weight loss. In this review, we discuss pathophysiological mechanisms underlying muscle loss in sarcopenia and cachexia, highlight similarities and differences of both conditions, and discuss therapeutic targets and possible treatments, such as exercise training, nutritional support, and drugs. Candidate drugs to treat muscle wasting disease include myostatin antagonists, ghrelin agonists, selective androgen receptor molecules, megestrol acetate, activin receptor antagonists, espindolol, and fast skeletal muscle troponin inhibitors.

SUMMARY

Present approaches to muscle wasting disease include exercise training, nutritional support, and drugs, although particularly the latter remain currently restricted to clinical studies. Optimizing skeletal muscle mass and function in ageing and chronic illness including heart failure is one of the chapters that are far from finished and gains future potential for new therapeutic interventions to come.

Improving functional capacity in heart failure: the need for a multifaceted approach

PURPOSE OF REVIEW

Functional capacity is a broad term that describes a person's ability to perform the daily activities that require physical exertion. Patients diagnosed with heart failure, regardless of cause, demonstrate a compromised functional capacity. The ability to perform aerobic activities is a central, but not complete, determinant of functional capacity. Muscular strength and endurance are other important elements of functional capacity. It is well established that patients with heart failure demonstrate attenuated muscular strength and endurance as a consequence of their disease process. Typically, a heart failure patient's ability to perform daily activities that are either aerobic or resistive in nature is compromised and contributes to the decline in functional capacity.

RECENT FINDINGS

There is an abundance of literature demonstrating that exercise training improves aerobic capacity and muscular strength and endurance in those with heart failure. These training benefits translate to an improvement in functional capacity and an enhanced ability to perform activities of daily living. There are several approaches to exercise training in the heart failure population, each of which has implications for the degree to which functional capacity can be improved.

SUMMARY

This review summarizes the current body of literature related to exercise training as a means of optimizing functional capacity in patients with heart failure.

Biological variation, reference change value (RCV) and minimal important difference (MID) of inspiratory muscle strength (PImax) in patients with stable chronic heart failure

BACKGROUND

Despite the widespread application of measurements of respiratory muscle force (PImax) in clinical trials there is no data on biological variation, reference change value (RCV), or the minimal important difference (MID) for PImax irrespective of the target cohort. We addressed this issue for patients with chronic stable heart failure.

METHODS AND RESULTS

From the outpatients' clinic of the University of Heidelberg we retrospectively selected three groups of patients with stable systolic chronic heart failure (CHF). Each group had two measurements of PImax: 90 days apart in Group A (n = 25), 180 days apart in Group B (n = 93), and 365 days apart in Group C (n = 184). Stability was defined as (a) no change in NYHA class between visits and (b) absence of cardiac decompensation 3 months prior, during, and 3 months after measurements. For each group, we determined within-subject (CVI), between-subject (CVG), and total (CVT) coefficient of variation (CV), the index of individuality (II), RCV, reliability coefficient, and MID of PImax. CVT was 8.7, 7.5, and 6.9 % for groups A, B, and C, respectively. The II and RCV were 0.21, 0.20, 0.16 and 13.6, 11.6, 10.8 %, respectively. The reliability coefficient and MID were 0.83, 0.87, 0.88 and 1.44, 1.06, 1.12 kPa, respectively. Results were similar between age, gender, and aetiology subgroups.

CONCLUSION

In patients with stable CHF, measurements of PImax are highly stable for intervals up to 1 year. The low values for II suggest that evaluation of change in PImax should be performed on an individual (per patient) basis. Individually significant change can be assumed beyond 14 % (RCV) or 1.12 kPa (MID).