Best mode of inspiratory muscle training in heart failure patients: a systematic review and meta-analysis

Diaphragm thickness and mobility elicited by two different modalities of inspiratory muscle loading in heart failure participants: A randomized crossover study

OBJECTIVES

To analyze diaphragmatic thickness, at end-inspiration and end-expiration, diaphragmatic thickening index and mobility via US under two different modalities of inspiratory muscle loading, in two different modalities of inspiratory muscle loading and different load intensities at full-vital capacity maneuvers and the relationship between diaphragmatic thickness with pulmonary function tests in participants with HF.

METHODS

This randomized crossover trial, enrolled with 17 HF subjects, evaluated diaphragm thickness (Tdi, mm), fractional thickness (TFdi, %), and mobility (mm) US during low and high intensities (30% and 60% of maximal inspiratory pressure-MIP) with two modalities of inspiratory muscle loading mechanical threshold loading (MTL) and tapered flow-resistive loading (TFRL).

RESULTS

Both MTL and TFRL produced a increase in Tdi, but only with high intensity loading compared to baseline-2.21 (0.26) vs. 2.68 (0.33) and 2.73 (0.44) mm; p = .01. TFdi was greater than baseline under all conditions, except during low intensity of TFRL. Diaphragm mobility was greater than baseline under all conditions, and high intensity of TFRL elicited greater mobility compared to all other conditions. Additionally, baseline Tdi was moderately correlated with pulmonary function tests.

CONCLUSIONS

MTL and TFRL modalities elicit similar increases in diaphragm thickness at loads, but only during high intensity loading it was greater than baseline. Diaphragm mobility was significantly greater than baseline under both loads and devices, and at high intensity compared to low intensity, although TFRL produced greater mobility compared to modalities of inspiratory muscle loading. There is an association between diaphragm thickness and pulmonary function tests.

Impact of Different Exercise Modalities on Physical Function and Quality of Life in Patients with Heart Failure

Heart failure, a chronic condition, often manifests with reduced physical function and an overall decline in quality of life. It is considered critical that patients with heart failure recover as soon as possible; exercise training, which includes aerobic exercise, resistance exercise, inspiratory muscle training, traditional mind-body exercise, and combined training, facilitates this. The research progress on the impact of various exercise modalities on the physical function and quality of life of patients with heart failure is systematically reviewed in this article. The objective is to augment the understanding of healthcare personnel regarding the status of implementation and outcomes associated with varied exercise modalities. This endeavor seeks to provide a point of reference for the development of exercise rehabilitation programs tailored to individuals contending with heart failure.

The future of group 2 pulmonary hypertension: Exploring clinical trials and therapeutic targets

Pulmonary hypertension due to left heart disease (PH-LHD) or group 2 PH is the most common and lethal form of PH, occurring secondary to left ventricular systolic or diastolic heart failure (HF), left-sided valvular diseases, and congenital abnormalities. It is subdivided into isolated postcapillary PH (IpcPH) and combined pre- and post-capillary PH (CpcPH), with the latter sharing many similarities with group 1 PH. CpcPH is associated with worse outcomes and increased morbidity and mortality when compared to IpcPH. Although IpcPH can be improved by treatment of the underlying LHD, CpcPH is an incurable disease for which no specific treatment exists, likely due to the lack of understanding of its underlying mechanisms. Furthermore, drugs approved for PAH are not recommended for group 2 PH, as they are either ineffective or even deleterious. With this major unmet medical need, a better understanding of mechanisms and the identification of effective treatment strategies for this deadly condition are urgently needed. This review presents relevant background of the molecular mechanisms underlying PH-LHD that could translate into innovative therapeutic targets and explores novel targets currently being evaluated in clinical trials.

Effectiveness of Nonpharmacological Interventions in the Field of Ventilation: An Umbrella Review

This umbrella review aimed to determine the effectiveness of nonpharmacological interventions in pulmonary ventilation and their impact on respiratory function. An individual with impaired ventilation displays visible variations manifested in their respiratory frequency, breathing rhythm ratio (I:E), thoracic symmetry, use of accessory muscles, dyspnea (feeling short of breath), oxygen saturation, diaphragm mobility, minute ventilation, peak flow, walking test, spirometry, Pimax/Pemax, diffusion, and respiratory muscle strength. Any variation in these markers demands the need for interventions in order to duly manage the signs and symptoms and to improve ventilation.

METHOD

Systematic reviews of the literature published in English, Spanish, French, and Portuguese were used, which included studies in which nonpharmacological interventions were used as a response to impaired ventilation in adults in any given context of the clinical practice. The recommendations given by the Joanna Briggs Institute (JBI) for umbrella reviews were followed. This research took place in several databases such as MEDLINE, CINAHL Complete, CINHAL, MedicLatina, ERIC, Cochrane Reviews (Embase), and PubMed. The Joanna Briggs critical analysis verification list was used for the systematic review. The data extraction was performed independently by two investigators based on the data extraction tools of the Joanna Briggs Institute, and the data were presented in a summary table alongside the support text.

RESULTS

Forty-four systematic reviews, thirty randomized clinical essays, and fourteen observational studies were included in this review. The number of participants varied between n = 103 and n = 13,370. Fifteen systematic revisions evaluated the effect of isolated respiratory muscular training; six systematic revisions evaluated, in isolation, breathing control (relaxed breathing, pursed-lip breathing, and diaphragmatic breathing exercises) and thoracic expansion exercises; and one systematic review evaluated, in isolation, the positions that optimize ventilation. Nineteen systematic reviews with combined interventions that reinforced the role of education and capacitation while also aiming for their success were considered. The articles analyzed isolated interventions and presented their efficacy. The interventions based on respiratory exercises and respiratory muscular training were the most common, and one article mentioned the efficacy of positioning in the compromisation of ventilation. Combined interventions in which the educational component was included were found to be effective in improving pulmonary function, diffusion, oxygenation, and functional capacity. The outcomes used in each study were variable, leading to a more difficult analysis of the data.

CONCLUSIONS

The interventions that were the focus of the review were duly mapped. The results suggest that nonpharmacological interventions used to optimize ventilation are effective, with a moderate to high level of evidence. There is a strong foundation for the use of the chosen interventions. The lack of studies on the intervention of "positioning to optimize ventilation" points out the need for a deeper analysis of its effects and for studies with a clear focus. This study supports the decisions and recommendations for the prescription of these interventions to patients with impaired ventilation.

The Need for Breathing Training Techniques: The Elephant in the Heart Failure Cardiac Rehabilitation Room: A Randomized Controlled Trial

BACKGROUND

Although solid evidence has indicated that respiratory symptoms are common amongst patients with chronic heart failure (CHF), state-of-the-art cardiac rehabilitation (CR) programs do not typically include management strategies to address respiratory symptoms. This study investigated the effect of the addition of breathing exercises (BE) to the CR programs in CHF.

METHODS

In a two parallel-arm randomized controlled study (RCT), 40 middle-aged patients with CHF and respiratory symptoms were recruited and randomized into two equal groups (n = 20); group (A): standard CR with BE and group (B): standard CR alone. Primary outcomes were respiratory parameters and secondary outcomes included cardiovascular and cardiopulmonary outcomes. All the participants attended a program of aerobic exercise (three sessions/week, 60-75% MHR, 45-55 min) for 12 weeks, plus educational, nutritional, and psychological counseling. Group (A) patients attended the same program together with BE using inspiratory muscle training (IMT) and breathing calisthenics (BC) (six sessions/week, 15-25 min) for the same duration.

RESULTS

There was a significant improvement in the respiratory outcomes, and most of the cardiovascular and cardiopulmonary outcomes in both groups with a greater change percentage in group A (p < 0.05).

CONCLUSIONS

These results indicate that the addition of BE to the CR programs in CHF is effective and is a "patient-centered" approach.

A comparison of the effects of inspiratory muscle strength and endurance training on exercise capacity, respiratory muscle strength and endurance, and quality of life in pacemaker patients with heart failure: A randomized study

BACKGROUND

Studies have widely investigated the effects of inspiratory muscle strength training in patients with heart failure (HF). The effects of inspiratory muscle strength or endurance training on outcomes in patients with pacemakers have not been adequately studied.

OBJECTIVES

The aim was to compare the effects of inspiratory muscle strength and endurance training on exercise capacity, quality of life (QoL), peripheral and respiratory muscle strength, respiratory muscle endurance, pulmonary function, dyspnea, fatigue, and physical activity levels in pacemaker patients with HF.

METHODS

A randomized, controlled, double-blind study was conducted. Fourteen pacemaker patients with HF received inspiratory muscle strength training (IMST) at 50% of maximal inspiratory pressure (MIP), and 18 patients received endurance training (IMET) at 30% of MIP 7 days/8 weeks. Exercise capacity [6 min. walking test (6MWT) and the Incremental Shuttle Walking Test (ISWT)], pulmonary function, respiratory muscle strength [MIP, maximal expiratory pressure (MEP)], endurance, peripheral muscle strength, dyspnea, fatigue, QoL, and physical activity level were evaluated before and after.

RESULTS

Demographic characteristics were similar in IMST (3F/11M, 56.92 ± 7.61y, EF: 25%, ICD/CRT:11/3) and IMET (4F/14M, 56 ± 10.77y, EF: 30%, ICD/CRT:16/2) groups (p > 0.05). Significant improvements were present in MIP, MEP, respiratory muscle endurance, peripheral muscle strength, 6MWT and ISWT walking distances, dyspnea, QoL, physical activity level, fatigue scores within groups (p ≤ 0.05). However, there were no significant differences between the groups (p > 0.05). There were no significant improvements in FEV₁%, FVC%, FEV₁/FVC%, and FEF_25-75 within and between the groups (p > 0.05).

CONCLUSIONS

Inspiratory muscle strength and endurance training similarly improves respiratory and peripheral muscle strength, exercise capacity, QoL, physical activity level, and decreases dyspnea and fatigue and are safe and effective in pacemaker patients with HF.

TRIAL REGISTRATION

www.

CLINICALTRIALS

gov; study number: NCT03501355.

The Effects of Exercise-Based Interventions on Fluid Overload Symptoms in Patients with Heart Failure: A Systematic Review and Meta-Analysis

Patients with heart failure are subjected to a substantial burden related to fluid overload symptoms. Exercise can help the lymphatic system function more effectively to prevent fluid build-up in tissues and interstitium, thus potentially mitigating the symptoms due to fluid overload. The objective of this systematic review was to examine the effects of exercise-based interventions on fluid overload symptoms among patients with heart failure. MEDLINE, Embase, Cochrane Library, and CINAHL databases were systematically searched for relevant studies published from inception to August 2021. We included randomized controlled trials that compared exercise-based interventions of different modalities and usual medical care for adult patients with heart failure and reported the effects of interventions on any symptoms related to fluid overload. A random-effects meta-analysis was used to estimate the effectiveness, and a subgroup analysis and univariate meta-regression analysis were used to explore heterogeneity. Seventeen studies covering 1086 participants were included. We found robust evidence indicating the positive effect of exercises in dyspnea relief (SMD = -0.48; 95%CI [-0.76, -0.19]; p = 0.001); the intervention length also influenced the treatment effect (β = 0.033; 95%CI [0.003, 0.063]; p = 0.04). Initial evidence from existing limited research showed that exercise-based intervention had positive effect to alleviate edema, yet more studies are needed to verify the effect. In contrast, the exercise-based interventions did not improve fatigue compared with usual care (SMD = -0.27; 95%CI [-0.61, 0.06]; p = 0.11). Findings regarding the effects of exercises on bodily pain, gastro-intestinal symptoms, and peripheral circulatory symptoms were inconclusive due to limited available studies. In conclusion, exercise-based interventions can be considered as an effective nonpharmacological therapy for patients with heart failure to promote lymph flow and manage fluid overload symptoms. Exercise-based interventions seem to have very limited effect on fatigue. More research should investigate the mechanism of fatigue related to heart failure. Future studies with high methodological quality and comprehensive assessment of symptoms and objective measure of fluid overload are warranted.

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.

The importance of physical activity and cardiorespiratory fitness for patients with heart failure

The present review highlights current research on the importance of PA and fitness for patients with heart failure and recommendations with respect to heart failure phenotypes and special populations. Furthermore, the evidence for various exercise types and intensities/doses as an "exercise prescription", are discussed. The strong association between heart failure and traditional risk factors, physical inactivity and low fitness, underlines the importance of regular PA and exercise for prevention and treatment of heart failure. This is illustrated by cardiac stiffness which typically accelerates in middle-life and could be reversed by aerobic exercise. In patients with HFpEF, regular PA counteracts many of the changes observed, both metabolic and functional. Indeed, exercise-based cardiac rehabilitation has received a class 1A recommendation in current guidelines [1], in order to improve functional capacity, quality of life and lower the risk of rehospitalization. An individually tailored plan based on risk stratification, clinical assessment and cardiopulmonary exercise testing is encouraged before initiation of exercise training in patients with heart failure. In general, a combination of aerobic exercise and resistance training protocols is recommended (Table 1) [2], preferably throughout life. More studies are needed, regarding the role of PA and exercise in specific populations, such as frail patients with heart failure.

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.

Comprehensive multicomponent cardiac rehabilitation in cardiac implantable electronic devices recipients: a consensus document from the European Association of Preventive Cardiology (EAPC; Secondary prevention and rehabilitation section) and European Heart Rhythm Association (EHRA)

Cardiac rehabilitation (CR) is a multidisciplinary intervention including patient assessment and medical actions to promote stabilization, management of cardiovascular risk factors, vocational support, psychosocial management, physical activity counselling, and prescription of exercise training. Millions of people with cardiac implantable electronic devices live in Europe and their numbers are progressively increasing, therefore, large subsets of patients admitted in CR facilities have a cardiac implantable electronic device. Patients who are cardiac implantable electronic devices recipients are considered eligible for a CR programme. This is not only related to the underlying heart disease but also to specific issues, such as psychological adaptation to living with an implanted device and, in implantable cardioverter-defibrillator patients, the risk of arrhythmia, syncope, and sudden cardiac death. Therefore, these patients should receive special attention, as their needs may differ from other patients participating in CR. As evidence from studies of CR in patients with cardiac implantable electronic devices is sparse, detailed clinical practice guidelines are lacking. Here, we aim to provide practical recommendations for CR in cardiac implantable electronic devices recipients in order to increase CR implementation, efficacy, and safety in this subset of patients.

Review of Trials on Exercise-Based Rehabilitation Interventions Following Acute Decompensated Heart Failure: OBSERVATIONS FROM THE WHO INTERNATIONAL CLINICAL TRIALS REGISTRY PLATFORM

PURPOSE

Cardiac rehabilitation is an important intervention for patients with heart failure. However, its clinical application in acute decompensated heart failure (ADHF) remains underutilized with limited research available. An assessment of current research in this area will help guide future investigations. The aim of this review is to summarize the current research focusing on rehabilitation interventions following recovery from ADHF.

REVIEW METHODS

A systematic search was carried out on all trials registered in the clinical trial registry database of the World Health Organization-International Clinical Trial Registry Platform (WHO-ICTRP). Studies focusing on ADHF and utilizing any exercise and rehabilitation-based intervention were included.

RESULTS

A majority of 11 trial protocols, including 3827 participants with low ejection fraction (<40%), were identified from the WHO-ICTRP database. Majority of the protocols (64%) focused on exercise-based interventions with approximately one-quarter (29%) focusing on neuromuscular electrical stimulation and one on noninvasive ventilation during exercise. Irrespective of the mode of exercise, all protocols employed low-moderate intensity training with outcomes focusing on physical function and quality of life.

CONCLUSION

Studies on rehabilitative interventions for ADHF are still in their early stages. More research is needed using innovative methodologies and testing for feasibility and fidelity.

Comprehensive multicomponent cardiac rehabilitation in cardiac implantable electronic devices recipients: a consensus document from the European Association of Preventive Cardiology (EAPC; Secondary prevention and rehabilitation section) and European Heart Rhythm Association (EHRA)

Cardiac rehabilitation (CR) is a multidisciplinary intervention including patient assessment and medical actions to promote stabilization, management of cardiovascular risk factors, vocational support, psychosocial management, physical activity counselling, and prescription of exercise training. Millions of people with cardiac implantable electronic devices live in Europe and their numbers are progressively increasing, therefore, large subsets of patients admitted in CR facilities have a cardiac implantable electronic device. Patients who are cardiac implantable electronic devices recipients are considered eligible for a CR programme. This is not only related to the underlying heart disease but also to specific issues, such as psychological adaptation to living with an implanted device and, in implantable cardioverter-defibrillator patients, the risk of arrhythmia, syncope, and sudden cardiac death. Therefore, these patients should receive special attention, as their needs may differ from other patients participating in CR. As evidence from studies of CR in patients with cardiac implantable electronic devices is sparse, detailed clinical practice guidelines are lacking. Here, we aim to provide practical recommendations for CR in cardiac implantable electronic devices recipients in order to increase CR implementation, efficacy, and safety in this subset of patients.

Inspiratory Muscle Training in Patients With Heart Failure: What Is New? Systematic Review and Meta-Analysis

OBJECTIVE

The benefits of inspiratory muscle training (IMT) have already been demonstrated in patients with heart failure (HF), but the best mode of training and which patients benefit from this intervention are not clear. The purpose of this study was to review the effects of IMT on respiratory muscle strength, functional capacity, pulmonary function, quality of life, and dyspnea in patients with HF; IMT isolated or combined with another intervention (combined IMT), the presence of inspiratory muscle weakness, training load, and intervention time were considered.

METHODS

The search included the databases MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Physiotherapy Evidence Database, and LILACS database through September 2019. The review included randomized studies that assessed IMT in isolation or combined with another intervention-in comparison with a control group, a placebo, or another intervention-in patients with HF. Fourteen studies were included, 13 for meta-analysis (10 for isolated IMT and 3 for combined IMT).

RESULTS

Isolated IMT demonstrated an increase in maximal inspiratory pressure (MIP) (25.12 cm H2O; 95% CI = 15.29 - 34.95), 6-Minute Walk Test (81.18 m; 95% CI = 9.73 - 152.63), maximum oxygen consumption (12 weeks: 3.75 mL/kg/min; 95% CI = 2.98 to 4.51), and quality of life (-20.68; 95% CI = -29.03 to -12.32). The presence of inspiratory muscle weakness, higher loads, and longer intervention times resulted in greater increases in MIP. IMT combined with another intervention demonstrated an increase only in MIP.

CONCLUSIONS

Isolated IMT resulted in an increase in inspiratory muscle strength, functional capacity, and quality of life. IMT combined with another intervention resulted only in a small increase in inspiratory strength. Isolated IMT with higher loads can be considered an adjuvant intervention, especially for those who do not adhere to conventional rehabilitation and who have respiratory muscle weakness.

IMPACT

A systematic review was necessary to review the effects of IMT on respiratory muscle strength, lung function, functional capacity, quality of life, and dyspnea in patients with HF. Various clinical issues important for a better training prescription were considered; these included whether the performance of the training IMT as a form of isolated training benefits patients with HF, whether the combination of IMT with another intervention has additional effects, whether any patient with HF can benefit from IMT (alone or combined with another intervention), and whether only patients who already have respiratory muscle weakness benefit. Also important was establishing which training load provides the best result and the best intervention time, so that health care can be provided more efficiently.

LAY SUMMARY

For people with heart failure, IMT by itself, without being combined with other exercise, can improve ease of breathing, increase the amount of distance that they can walk, and improve quality of life. Inspiratory training with higher loads might be helpful for those with respiratory muscle weakness who are unable to do conventional exercise.

Correlação da força muscular respiratória com medidas antropométricas e nível de atividade física em adultos da atenção primária

RESUMO O objetivo deste estudo foi correlacionar a força muscular respiratória com as medidas antropométricas e o nível de atividade física de indivíduos adultos da atenção primária. Trata-se de um estudo transversal, realizado em uma unidade básica de saúde, onde foram incluídos indivíduos de ambos os sexos e com idade superior a 18 anos. A força muscular respiratória foi analisada pela pressão inspiratória máxima (PImáx) e pressão expiratória máxima (PEmáx), por meio do manovacuômetro, onde valores pressóricos acima de 80% em relação ao predito foram considerados normais. Utilizou-se balança mecânica, estadiômetro e fita métrica para mensuração das principais medidas antropométricas: índice de massa corporal (IMC), circunferência de pescoço (CP), circunferência abdominal (CA), circunferência de quadril (CQ), relação cintura-quadril (RCQ) e o índice de adiposidade corporal (IAC). O nível de atividade física foi determinado pelo questionário internacional de atividade física (IPAQ), onde os indivíduos foram categorizados como sedentário, irregularmente ativo A, irregularmente ativo B, ativo ou muito ativo, sendo realizada também a estimativa dos equivalentes metabólicos (MET) alcançados. Foram avaliados 110 indivíduos adultos (78,1% do sexo feminino; 51,9±12,3 anos), e com porcentagem em relação ao predito (%) de PImáx de 96,3±32,4% e 98,9±27,3% de PEmáx. A %PImáx apresentou fraca correlação com o IAC (r=0,23; p=0,01) e com a CQ (r=0,20; p=0,03), e a %PEmáx com o IMC (r=0,26; p<0,01) e IAC (r=0,30; p<0,01). Não houve diferença dos valores médios de %PImáx (p=0,61) e %PEmáx (p=0,54) entre as categorias do IPAQ, além de não existirem correlações (p>0,05) com os MET estimados. Em adultos da atenção primária, a força muscular respiratória apresentou fraca correlação com IMC, CQ e IAC, porém sem correlação com o nível de atividade física.

Inspiratory Muscle Training on Glucose Control in Diabetes: A Randomized Clinical Trial

This study evaluated the effects of inspiratory muscle training (IMT) in glucose control and respiratory muscle function in patients with diabetes. It was a randomized clinical trial conducted at the Physiopathology Laboratory of the Hospital de Clínicas de Porto Alegre. Patients with Type 2 diabetes were randomly assigned to IMT or placebo-IMT (P-IMT), performed at 30% and 2% of maximal inspiratory pressure, respectively, every day for 12 weeks. The main outcome measures were HbA1c, glycemia, and respiratory muscle function. Thirty patients were included: 73.3% women, 59.6 ± 10.7 years old, HbA1c 8.7 ± 0.9% (71.6 ± 9.8 mmol/mol), and glycemia 181.8 ± 57.8 mg/dl (10.5 ± 3.2 mmol/L). At the end of the training, HbA1c was 8.2 ±0.3% (66.1 ± 3.3 mmol/mol) and 8.7 ± 0.3% (71.6 ± 3.3 mmol/mol) for the IMT and P-IMT groups, respectively (p = .8). Fasting glycemia decreased in both groups with no difference after training although it was lower in IMT at 8 weeks: 170.0 ± 11.4 mg/dl(9.4 ± 0.6 mmol/L) and 184.4 ± 15.0 mg/dl (10.2 ± 0.8 mmol/L) for IMT and P-IMT, respectively (p < .05). Respiratory endurance time improved in the IMT group (baseline = 325.9 ± 51.1 s and 305.0 ± 37.8 s; after 12 weeks = 441.1 ± 61.7 s and 250.7 ± 39.0 s for the IMT and P-IMT groups, respectively; p < .05). Considering that glucose control did not improve, IMT should not be used as an alternative to other types of exercise in diabetes. Higher exercise intensities or longer training periods might produce better results. The clinical trials identifier is NCT03191435.

Controlled Study of Central Hemodynamic Changes in Inspiratory Exercise with Different Loads in Heart Failure

Background Inspiratory muscle weakness contributes to exercise intolerance and decreased quality of life in patients with heart failure. Studies with inspiratory muscle training show improvement in inspiratory muscle strength, functional capacity and quality of life. However, little is known about the central hemodynamic response (CHR) during inspiratory exercise (IE). Objective To evaluate CHR in a single IE session with different loads (placebo, 30% and 60%) in heart failure. Methods Randomized placebo-controlled clinical trial in patients with heart failure with reduced ejection fraction, functional class II and III. Twenty patients aged 65 ± 11 years completed a single session of inspiratory exercise, in 3 cycles of 15 minutes, with a 1-hour washout, involving loads of 30% (C30), 60% (C60) and placebo, using a linear load resistor (PowerBreathe Light). The noninvasive hemodynamic study was performed by cardiothoracic bioimpedance (Niccomo™ CardioScreen®). Statistical analysis was performed with Student's t-test and Pearson's correlation, and P≤0.05 was considered significant. Results An increase in heart rate (HR) was observed with C30 (64 ± 15 vs 69 ± 15 bpm; p = 0.005) and C60 (67 ± 14 vs 73 ± 14 bpm, p = 0.002). A decrease was observed in systolic volume (SV) with C30 (73 ± 26 vs 64 ± 20 ml; p = 0.004). Cardiac output (CO), on its turn, increased only with C60 (4.6 ± 1.5 vs 5.3 ± 1.7 l/min; p = -0.001). Conclusion When using the 60% load, in a single IE session, changes in CHR were observed. HR and CD increased, as did the Borg scales and subjective sensation of dyspnea. The 30% load reduced the SV. (Arq Bras Cardiol. 2020; 114(4):656-663).

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.

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.