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

Recent Advancements in Our Understanding of the Ergogenic Effect of Respiratory Muscle Training in Healthy Humans: A Systematic Review

Shei, R-J. Recent advancements in our understanding of the ergogenic effect of respiratory muscle training in healthy humans: a systematic review. J Strength Cond Res 32(9): 2674-2685, 2018-Respiratory muscle training (RMT) has been shown to be an effective ergogenic aid for sport performance. Respiratory muscle training has been documented to improve performance in a wide range of exercise modalities including running, cycling, swimming, and rowing. The physiological effects of RMT that may explain the improvements in performance have been proposed to include diaphragm hypertrophy, muscle fiber-type switching, improved neural control of the respiratory muscles, increased respiratory muscle economy, attenuation of the respiratory muscle metaboreflex, and decreases in perceived breathlessness and exertion. This review summarizes recent studies on the ergogenicity and mechanisms of RMT since 2013 when the topic was last systematically reviewed. Recent evidence confirms the ergogenic effects of RMT and explores different loading protocols, such as concurrent exercise and RMT (i.e., "functional" RMT). These studies suggest that adapting new training protocols may have an additive improvement effect, but evidence of the efficacy of such an approach is conflicting thus far. Other recent investigations have furthered our understanding of the mechanisms underpinning RMT-associated improvements in performance. Importantly, changes in ventilatory efficiency, oxygen delivery, cytokine release, motor recruitment patterns, and respiratory muscle fatigue resistance are highlighted as potential mechanistic factors linking RMT with performance improvements. It is suggested that future investigations focus on development of sport-specific RMT loading protocols, and that further work be undertaken to better understand the mechanistic basis of RMT-induced performance improvements.

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).

Can diaphragmatic breathing modify chest wall volumes during inspiratory loaded breathing in patients with heart failure?

BACKGROUND

Some inspiratory muscle training protocols for patients with heart failure report the request of diaphragmatic breathing during inspiratory loaded breathing. However, it is unclear whether this condition modifies the chest wall volumes.

OBJECTIVE

The primary purpose was to evaluate chest wall volumes during inspiratory loaded breathing as well as during inspiratory loaded breathing associated with diaphragmatic breathing in patients with heart failure.

METHODS

Sixteen men with heart failure functional class I to III, aged 50(SD=7) years were evaluated. Volumes of the pulmonary rib cage, abdominal rib cage and abdomen, as well as other breathing pattern variables, were assessed by optoelectronic plethysmography during quiet breathing, inspiratory loaded breathing, and inspiratory loaded breathing associated with diaphragmatic breathing.

RESULTS

Chest wall tidal volume significantly increased from quiet breathing 0.53(SD=0.14)L to inspiratory loaded breathing 1.33(SD=0.48)L and to inspiratory loaded breathing associated with diaphragmatic breathing 1.36(SD=0.48)L. A significant volume variation was observed on the three compartments (p<0.05 for all). During inspiratory loaded breathing associated with diaphragmatic breathing, patients showed increased abdominal volume compared to quiet breathing [0.28(SD=0.05) to 0.83(SD=0.47)L, p<0.001]; as well as from inspiratory loaded breathing [0.63(SD=0.23) to 0.83(SD=0.47)L, p=0.044]. No significant changes were observed between the two inspiratory loaded breathing conditions on the percentages of the contribution of each chest wall compartment for the tidal volume, respiratory rate, minute ventilation, and duty cycle.

CONCLUSION

When inspiratory loaded breathing was associated with diaphragmatic breathing, a higher volume in the abdominal compartment was obtained without significant changes in other breathing pattern variables.

Inspiratory Muscle Training and Functional Electrical Stimulation for Treatment of Heart Failure With Preserved Ejection Fraction: The TRAINING-HF Trial

INTRODUCTION AND OBJECTIVES

Despite the prevalence of heart failure with preserved ejection fraction (HFpEF), there is currently no evidence-based effective therapy for this disease. This study sought to evaluate whether inspiratory muscle training (IMT), functional electrical stimulation (FES), or a combination of both (IMT + FES) improves 12- and 24-week exercise capacity as well as left ventricular diastolic function, biomarker profile, and quality of life in HFpEF.

METHODS

A total of 61 stable symptomatic patients (New York Heart Association II-III) with HFpEF were randomized (1:1:1:1) to receive a 12-week program of IMT, FES, or IMT + FES vs usual care. The primary endpoint of the study was to evaluate change in peak exercise oxygen uptake at 12 and 24 weeks. Secondary endpoints were changes in quality of life, echocardiogram parameters, and prognostic biomarkers. We used a mixed-effects model for repeated-measures to compare endpoints changes.

RESULTS

Mean age and peak exercise oxygen uptake were 74 ± 9 years and 9.9 ± 2.5mL/min/kg, respectively. The proportion of women was 58%. At 12 weeks, the mean increase in peak exercise oxygen uptake (mL/kg/min) compared with usual care was 2.98, 2.93, and 2.47 for IMT, FES, and IMT + FES, respectively (P < .001) and this beneficial effect persisted after 6 months (1.95, 2.08, and 1.56; P < .001). Significant increases in quality of life scores were found at 12 weeks (P < .001). No other changes were found.

CONCLUSIONS

In HFpEF patients with low aerobic capacity, IMT and FES were associated with a significant improvement in exercise capacity and quality of life. This trial was registered at ClinicalTrials.gov (Identifier: NCT02638961)..

[Cardiac rehabilitation in heart failure]

Heart failure is a malignant disorder with increasing prevalence and a high socioeconomic impact. Sceletal muscle myopathy seems to play a key role in the development of exercise intolerance. Cardiac rehabilitation for heart failure mainly adresses training, namely moderate continuous endurance training or interval training in combination with resistance training, and is highly recommended in the current ESC-guidelines. Following a multimodal concept cardiac rehabilitation also implements optimisation of neurohumoral therapy, education and counselling to empower self-care as well as psychosocial support.

Inspiratory Muscle Training Is Associated With Improved Inspiratory Muscle Strength, Resting Cardiac Output, and the Ventilatory Efficiency of Exercise in Patients With a Fontan Circulation

BACKGROUND

Patients with a Fontan circulation have reduced exercise capacity and respiratory muscle strength. Inspiratory muscle training (IMT) improves exercise capacity and quality of life in adults with heart failure. We assessed whether 6 weeks of a home-based program of IMT improves inspiratory muscle strength and the ventilatory efficiency of exercise in adolescent patients with a Fontan circulation.

METHODS AND RESULTS

Twenty-three adolescent participants (aged 16±2 years) with a Fontan circulation underwent 6 weeks of IMT for 30 minutes daily. Respiratory muscle strength (maximal inspiratory pressure and expiratory pressure), lung function, and exercise capacity (cardiopulmonary exercise testing) were assessed. Fourteen of 23 participants also underwent exercise cardiac magnetic resonance imaging to examine the effects of IMT on cardiac output and systemic and pulmonary blood flow. Six weeks of IMT improved maximal inspiratory pressure by 36±24 cm H₂O (61±46%) with no change in maximal expiratory pressure. Ventilatory efficiency of exercise improved after 6 weeks of IMT (from 34.2±7.8 to 32.2±5.6, P=0.04). In those who underwent exercise cardiac magnetic resonance imaging, IMT increased resting cardiac output (from 4.2±1.2 to 4.5±1.0 L/min, P=0.03) and ejection fraction (from 50.1±4.3 to 52.8±6.1%, P=0.03).

CONCLUSIONS

Six weeks of IMT is associated with improved inspiratory muscle strength, ventilatory efficiency of exercise, and resting cardiac output in young Fontan patients. IMT may be a simple beneficial addition to the current management of Fontan patients, potentially reducing exercise intolerance and long-term morbidity and mortality.

Abdominal Binding Improves Neuromuscular Efficiency of the Human Diaphragm during Exercise

We tested the hypothesis that elastic binding of the abdomen (AB) would enhance neuromuscular efficiency of the human diaphragm during exercise. Twelve healthy non-obese men aged 24.8 ± 1.7 years (mean ± SE) completed a symptom-limited constant-load cycle endurance exercise test at 85% of their peak incremental power output with diaphragmatic electromyography (EMGdi) and respiratory pressure measurements under two randomly assigned conditions: unbound control (CTRL) and AB sufficient to increase end-expiratory gastric pressure (Pga,ee) by 5-8 cmH₂O at rest. By design, AB increased Pga,ee by 6.6 ± 0.6 cmH₂O at rest. Compared to CTRL, AB significantly increased the transdiaphragmatic pressure swing-to-EMGdi ratio by 85-95% during exercise, reflecting enhanced neuromuscular efficiency of the diaphragm. By contrast, AB had no effect on spirometric parameters at rest, exercise endurance time or an effect on cardiac, metabolic, ventilatory, breathing pattern, dynamic operating lung volume, and perceptual responses during exercise. In conclusion, AB was associated with isolated and acute improvements in neuromuscular efficiency of the diaphragm during exercise in healthy men. The implications of our results are that AB may be an effective means of enhancing neuromuscular efficiency of the diaphragm in clinical populations with diaphragmatic weakness/dysfunction.

Inspiratory muscle training improves respiratory muscle strength, functional capacity and quality of life in patients with chronic kidney disease: a systematic review

QUESTION

Does inspiratory muscle training improve respiratory muscle strength, functional capacity, lung function and quality of life of patients with chronic kidney disease? Does inspiratory muscle training improve these outcomes more than breathing exercises?

DESIGN

Systematic review and meta-analysis of randomised trials.

PARTICIPANTS

People with chronic kidney disease undergoing dialysis treatment.

OUTCOME MEASURES

The primary outcomes were: maximal inspiratory pressure, maximal expiratory pressure, and distance covered on the 6-minute walk test. The secondary outcomes were: forced vital capacity, forced expiratory volume in the first second (FEV₁), and quality of life.

RESULTS

The search identified four eligible studies. The sample consisted of 110 participants. The inspiratory muscle training used a Threshold^® or PowerBreathe^® device, with a load ranging from 30 to 60% of the maximal inspiratory pressure and lasting from 6 weeks to 6 months. The studies showed moderate to high risk of bias, and the quality of the evidence was rated low or very low, due to the studies' methodological limitations. The meta-analysis showed that inspiratory muscle training significantly improved maximal inspiratory pressure (MD 23 cmH₂O, 95% CI 16 to 29) and the 6-minute walk test distance (MD 80m, 95% CI 41 to 119) when compared with controls. Significant benefits in lung function and quality of life were also identified. When compared to breathing exercises, significant benefits were identified in maximal expiratory pressure (MD 6 cmH₂O, 95% CI 2 to 10) and FEV₁ (MD 0.24litres 95% CI 0.14 to 0.34), but not maximal inspiratory pressure or forced vital capacity.

CONCLUSION

In patients with chronic renal failure on dialysis, inspiratory muscle training with a fixed load significantly improves respiratory muscle strength, functional capacity, lung function and quality of life. The evidence for these benefits may be influenced by some sources of bias.

REGISTRATION

PROSPERO (CRD 42015029986). [de Medeiros AIC, Fuzari HKB, Rattesa C, Brandão DC, de Melo Marinho PÉ (2017) Inspiratory muscle training improves respiratory muscle strength, functional capacity and quality of life in patients with chronic kidney disease: a systematic review. Journal of Physiotherapy 63: 76-83].

Exercise-Based Rehabilitation for Heart Failure: Clinical Evidence

People with heart failure experience marked reduction in their exercise capacity which has detrimental effects on their activities of daily living, health-related quality of life, and ultimately their hospital ad-mission rate and mortality. Numerous cardiac rehabilitation studies have demonstrated functional benefits, improvement in quality of life and clinical outcomes from exercise training in patients with HFrEF. Based on evidences, the American College of Cardiology/American Heart Association, European Society of Cardiology, and National Institute for Health and Care Excellence(NICE) consistently recommend exercise-based cardiac rehabilitation(CR) as an effective and safe adjunct for patients with stable class II to III heart failure (HF) who do not have advanced arrhythmias and who do not have other limitations to exercise. This recommendation applies to patients with HFrEF as well as to patients with HFpEF besides patients with class IV HF, although the data are not as robust for patients with HFpEF. In this article, the clinical evidence on effects of exercise for HFrEF and HFpEF as well as end-stage heart failure were separately reviewed.

Inspiratory muscle training in stroke patients with congestive heart failure: A CONSORT-compliant prospective randomized single-blind controlled trial

BACKGROUND

Cardiopulmonary function can be adversely affected after a cerebrovascular accident in patients with congestive heart failure (CHF). The aim of this study was to investigate the efficacy and feasibility of inspiratory muscle training (IMT) for stroke patients with CHF.

METHODS

A prospective randomized single-blind controlled trial was conducted in a single tertiary medical center in southern Taiwan between May 2011 and July 2015. Forty-one patients were enrolled, of whom 21 completed the study (IMT group n = 11 and control group n = 10). Both groups participated in a conventional stroke rehabilitation program. Patients in the IMT group received an additional IMT program beginning with an intensity of 30% maximal inspiratory pressure (MIP), then increased by 2cmH2O each week for 30 minutes daily for at least 5 days a week for 10 weeks. MIP, maximal expiratory pressure, spirometry, resting oxyhemoglobin saturation, modified Borg Scale, Fatigue Assessment Scale, and Barthel Index were assessed in each patient.

RESULTS

There were significant differences from baseline in MIP (P = 0.008), percent predicted forced vital capacity (P = 0.033), forced expiratory volume in 1 second (FEV1) (P = 0.008), percent predicted FEV1 (P = 0.008), and Barthel Index (P = 0.012) in the IMT group, and Barthel Index (P = 0.027) in the control group. There were significant differences between groups in MIP (20.91 ± 19.73 vs -9.00 ± 26.01, adjusted P value = 0.023) and Barthel Index (24.55 ± 22.30 vs 7.50 ± 8.25, adjusted P value = 0.044).

CONCLUSION

The 10-week IMT was feasible and effective in improving inspiratory force and activities of daily living for the stroke patients with CHF.

Inspiratory Muscle Training and Functional Electrical Stimulation for Treatment of Heart Failure With Preserved Ejection Fraction: Rationale and Study Design of a Prospective Randomized Controlled Trial

Heart failure with preserved ejection fraction (HFpEF) has become the most prevalent form of heart failure in developed countries. Regrettably, there is no evidence-based effective therapy for HFpEF. We seek to evaluate whether inspiratory muscle training, functional electrical stimulation, or a combination of both can improve exercise capacity as well as left ventricular diastolic function, biomarker profile, quality of life (QoL), and prognosis in patients with HFpEF. A total of 60 stable symptomatic patients with HFpEF (New York Heart Association class II-III/IV) will be randomized (1:1:1:1) to receive a 12-week program of inspiratory muscle training, functional electrical stimulation, a combination of both, or standard care alone. The primary endpoint of the study is change in peak exercise oxygen uptake; secondary endpoints are changes in QoL, echocardiogram parameters, and prognostic biomarkers. As of March 21, 2016, thirty patients have been enrolled. Searching for novel therapies that improve QoL and autonomy in the elderly with HFpEF has become a health care priority. We believe that this study will add important knowledge about the potential utility of 2 simple and feasible physical interventions for the treatment of advanced HFpEF.

Effects of inspiratory muscle training on pulmonary function, respiratory muscle strength and functional capacity in patients with atrial fibrillation: a randomized controlled trial

Objective:

To investigate the effects of inspiratory muscle training on pulmonary function, respiratory muscle strength and functional capacity in patients with atrial fibrillation.

Design:

Prospective randomized controlled single-blind study.

Setting:

Cardiology department of a university hospital.

Subjects:

A total of 38 patients with permanent atrial fibrillation were randomly allocated to either a treatment group ( n = 19; age 66.2 years (8.8)) or a control group ( n = 19; age 67.1 years (6.4)).

Methods:

The training group received inspiratory muscle training at 30% of maximal inspiratory pressure for 15 minutes twice a day, 7 days a week, for 12 weeks alongside the standard medical treatment. The control group received standard medical treatment only. Spirometry, maximal inspiratory and expiratory pressures and 6-minute walking distance was measured at the beginning and end of the study.

Results:

There was a significant increase in maximal inspiratory pressure (27.94 cmH2O (8.90)), maximal expiratory pressure (24.53 cmH2O (10.34)), forced vital capacity (10.29% (8.18) predicted), forced expiratory volume in one second (13.88% (13.42) predicted), forced expiratory flow 25%–75% (14.82% (12.44) predicted), peak expiratory flow (19.82% (15.62) predicted) and 6-minute walking distance (55.53 m (14.13)) in the training group ( p < 0.01). No significant changes occurred in the control group ( p > 0.05).

Conclusion:

Inspiratory muscle training can improve pulmonary function, respiratory muscle strength and functional capacity in patients with atrial fibrillation.

Comparison of Different Forms of Exercise Training in Patients With Cardiac Disease: Where Does High-Intensity Interval Training Fit?

In this review, we discuss the most recent forms of exercise training available to patients with cardiac disease and their comparison or their combination (or both) during short- and long-term (phase II and III) cardiac rehabilitation programs. Exercise training modalities to be discussed include inspiratory muscle training (IMT), resistance training (RT), continuous aerobic exercise training (CAET), and high-intensity interval training (HIIT). Particular emphasis is placed on HIIT compared or combined (or both) with other forms such as CAET or RT. For example, IMT combined with CAET was shown to be superior to CAET alone for improving functional capacity, ventilatory function, and quality of life in patients with chronic heart failure. Similarly, RT combined with CAET was shown to optimize benefits with respect to functional capacity, muscle function, and quality of life. Furthermore, in recent years, HIIT has emerged as an alternative or complementary (or both) exercise modality to CAET, providing equivalent if not superior benefits to conventional continuous aerobic training with respect to aerobic fitness, cardiovascular function, quality of life, efficiency, safety, tolerance, and exercise adherence in both short- and long-term training studies. Finally, short-interval HIIT was shown to be useful in the initiation and improvement phases of cardiac rehabilitation, whereas moderate- or longer-interval (or both) HIIT protocols appear to be more appropriate for the improvement and maintenance phases because of their high physiological stimulus. We now propose progressive models of exercise training (phases II-III) for patients with cardiac disease, including a more appropriate application of HIIT based on the scientific literature in the context of a multimodal cardiac rehabilitation program.

Validation of a new tool for the assessment of study quality and reporting in exercise training studies: TESTEX

INTRODUCTION

Several established tools are available to assess study quality and reporting of randomized controlled trials; however, these tools were designed with clinical intervention trials in mind. In exercise training intervention trials some of the traditional study quality criteria, such as participant or researcher blinding, are extremely difficult to implement.

METHODS

We developed the Tool for the assEssment of Study qualiTy and reporting in EXercise (TESTEX) - a study quality and reporting assessment tool, designed specifically for use in exercise training studies. Our tool is a 15-point scale (5 points for study quality and 10 points for reporting) and addresses previously unmentioned quality assessment criteria specific to exercise training studies.

RESULTS

There were no systematic differences between the summated TESTEX scores of each observer [H(2)=0.392, P=0.822]. There was a significant association between the summated TESTEX scores of the three observers, with almost perfect agreement between observers 1 and 2 [intra-class correlation coefficient (ICC)=0.93, 95% confidence interval (CI) 0.82-0.97, P<0.001], observers 1 and 3 (ICC= 0.96, 95% CI 0.89-0.98, P<0.001) and observers 2 and 3 (ICC=0.91, 95% CI 0.75-0.96, P<0.001).

CONCLUSIONS

The TESTEX scale is a new, reliable tool, specific to exercise scientists, that facilitates a comprehensive review of exercise training trials.

Exercise Training in Group 2 Pulmonary Hypertension: Which Intensity and What Modality

Pulmonary hypertension (PH) due to left-sided heart disease (LSHD) is a common and disconcerting occurrence. For example, both heart failure (HF) with preserved and reduced ejection fraction (HFpEF and HFrEF) often lead to PH as a consequence of a chronic elevation in left atrial filling pressure. A wealth of literature demonstrates the value of exercise training (ET) in patients with LSHD, which is particularly robust in patients with HFrEF and growing in patients with HFpEF. While the effects of ET have not been specifically explored in the LSHD-PH phenotype (i.e., composite pathophysiologic characteristics of patients in this advanced disease state), the overall body of evidence supports clinical application in this subgroup. Moderate intensity aerobic ET significantly improves peak oxygen consumption, quality of life and prognosis in patients with HF. Resistance ET significantly improves muscle strength and endurance in patients with HF, which further enhance functional capacity. When warranted, inspiratory muscle training and neuromuscular electrical stimulation are becoming recognized as important components of a comprehensive rehabilitation program. This review will provide a detailed account of ET programing considerations in patients with LSHD with a particular focus on those concomitantly diagnosed with PH.

Novel methods of inspiratory muscle training via the Test of Incremental Respiratory Endurance (TIRE)

The favorable effects of inspiratory muscle training (IMT) in health and disease are becoming much more apparent. A variety of IMT methods exist, but few studies have compared IMT methods. The purpose of this article is to review the methods and outcomes of the Test of Incremental Respiratory Endurance (TIRE).

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.

High prevalence of respiratory muscle weakness in hospitalized acute heart failure elderly patients

INTRODUCTION

Respiratory Muscle Weakness (RMW) has been defined when the maximum inspiratory pressure (MIP) is lower than 70% of the predictive value. The prevalence of RMW in chronic heart failure patients is 30 to 50%. So far there are no studies on the prevalence of RMW in acute heart failure (AHF) patients.

OBJECTIVES

Evaluate the prevalence of RMW in patients admitted because of AHF and the condition of respiratory muscle strength on discharge from the hospital.

METHODS

Sixty-three patients had their MIP measured on two occasions: at the beginning of the hospital stay, after they had reached respiratory, hemodynamic and clinical stability and before discharge from the hospital. The apparatus and technique to measure MIP were adapted because of age-related limitations of the patients. Data on cardiac ejection fraction, ECG, brain natriuretic peptide (BNP) levels and on the use of noninvasive ventilation (NIV) were collected.

RESULTS

The mean age of the 63 patients under study was 75 years. On admission the mean ejection fraction was 33% (95% CI: 31-35) and the BNP hormone median value was 726.5 pg/ml (range: 217 to 2283 pg/ml); 65% of the patients used NIV. The median value of MIP measured after clinical stabilization was -52.7 cmH2O (range: -20 to -120 cmH2O); 76% of the patients had MIP values below 70% of the predictive value. On discharge, after a median hospital stay of 11 days, the median MIP was -53.5 cmH2O (range:-20 to -150 cmH2O); 71% of the patients maintained their MIP values below 70% of the predictive value. The differences found were not statistically significant.

CONCLUSION

Elderly patients admitted with AHF may present a high prevalence of RMW on admission; this condition may be maintained at similar levels on discharge in a large percentage of these patients, even after clinical stabilization of the heart condition.

Clinical characteristics and course of patients with diabetes entering cardiac rehabilitation

BACKGROUND

Using data from the Italian SurveY on carDiac rEhabilitation (ISYDE-2008), this study provides insight into the level of implementation of Cardiac Rehabilitation (CR) in patients with diabetes.

METHODS

Data from 165 CR units were collected online from January 28th to February 10th, 2008.

RESULTS

The study cohort consisted of 2281 patients (66.9 ± 12 yrs); 475 (69.7 ± 10 yrs, 74% male) patients with diabetes and 1806 (66.2 ± 12 yrs, 72% male) non-diabetic patients. Compared to non-diabetic patients, patients with diabetes were older and showed more comorbidity [myocardial infarction (32% vs. 19%, p < 0.0001), peripheral artery disease (10% vs. 5%, p < 0.0001), chronic obstructive pulmonary disease (20% vs. 11%, p < 0.0001), chronic kidney disease (20% vs. 6%, p < 0.0001), and cognitive impairment (5% vs. 2%, p = 0.0009), respectively], and complications during CR [re-infarction (3% vs. 1%, p = 0.04), acute renal failure (9% vs. 4%, p < 0.0001), sternal revision (3% vs. 1%, p = 0.01), inotropic support/mechanical assistance (7% vs. 4%, p = 0.01), respectively]; a more complex clinical course and interventions with less functional evaluation and a different pattern of drug therapy at hospital discharge. Notably, in 51 (3%) and in 104 (6%) of the non-diabetic cohort, insulin and hypoglycemic agents were prescribed, respectively, at hospital discharge from CR suggesting a careful evaluation of the glycemic metabolism during CR program, independent of the diagnosis at the admission. Mortality was similar among diabetic compared to non-diabetic patients (1% vs. 0.5%, p = 0.23).

CONCLUSIONS

This survey provided a detailed overview of the clinical characteristics, complexity and more severe clinical course of diabetic patients admitted to CR.

Resistive inspiratory muscle training in people with spinal cord injury during inpatient rehabilitation: a randomized controlled trial

BACKGROUND

People with spinal cord injury (SCI) may benefit from resistive inspiratory muscle training (RIMT). Current evidence is weak, and little is known about the effect on functional outcomes and long-term effects.

OBJECTIVE

The purpose of this study was to assess immediate and long-term effects of RIMT in people with SCI.

DESIGN

This was a single-blinded randomized controlled trial.

SETTING

The study was conducted at 4 specialized SCI units in the Netherlands.

PATIENTS

The study participants were 40 people with SCI (15 with motor complete tetraplegia, 16 with incomplete tetraplegia, 8 with motor complete paraplegia, and 1 with incomplete paraplegia) who had impaired pulmonary function and were admitted for initial inpatient rehabilitation.

INTERVENTION

Study participants were randomized to an RIMT group or a control group. All participants received usual rehabilitation care. In addition, participants in the intervention group performed RIMT with a threshold trainer.

MEASUREMENTS

Measurements were performed at baseline, after 8 weeks of intervention, 8 weeks later, and 1 year after discharge from inpatient rehabilitation. Primary outcome measures were: respiratory muscle function, lung volumes and flows, and perceived respiratory function. Secondary outcome measures concerned patient functioning, which included health-related quality of life, limitations in daily life due to respiratory problems, and respiratory complications.

RESULTS

During the intervention period, maximum inspiratory pressure (MIP) improved more in the RIMT group than in the control group (11.7 cm H2O, 95% confidence interval=4.3 to 19.0). At follow-up, this effect was no longer significant. No effect on other primary or secondary outcome measures was found except for an immediate effect on mental health.

LIMITATIONS

The sample size was insufficient to study effects on respiratory complications.

CONCLUSIONS

Resistive inspiratory muscle training has a positive short-term effect on inspiratory muscle function in people with SCI who have impaired pulmonary function during inpatient rehabilitation.

Inspiratory muscle training in heart disease and heart failure: a review of the literature with a focus on method of training and outcomes

Evidence to date strongly suggests that poor inspiratory muscle performance is associated with dyspnea, poor exercise tolerance and poor functional status in patients with heart failure (HF). A growing body of literature has examined the effects of inspiratory muscle training (IMT) in HF patients with the majority of studies reporting favorable effects on several of the above limitations and a substantial number of related deficiencies due to inadequate inspiration and inspiratory muscle strength and endurance. The domains and manifestations of HF, which were significantly improved by IMT in one or more of the 18 out of 19 studies of IMT, included dyspnea, quality of life, balance, peripheral muscle strength and blood flow, peripheral muscle sympathetic nervous activity, heart rate, respiratory rate, peak VO₂, 6-min walk test distance, ventilation, VE/VCO₂ slope, oxygen uptake efficiency, circulatory power, recovery oxygen kinetics and several indices of cardiac performance. This paper will also review the available IMT literature with a focus on methods of IMT and clinical outcomes. Key differences between available IMT methods will be highlighted with a goal to improve IMT efforts and decrease the pathophysiological manifestations of heart disease and HF.