Markedly improved skeletal muscle function with local muscle training in patients with chronic heart failure

High-Intensity Small Muscle Mass Training in Patients With Heart Failure: Rationale and Design of a Randomized Controlled Trial

OBJECTIVE

Small muscle mass training localized to the quadriceps femoris muscle group has been proposed as an intervention to reverse heart failure-related skeletal muscle impairments. Although this training paradigm has demonstrated efficacy in heart failure, it remains to be evaluated in a conventional clinical context. Hence, the aim of this proposed study is to determine the effects of integrating high-intensity small muscle mass training (HISMT) isolated to the knee extensor muscles within a standard heart failure rehabilitation program.

METHODS

This single-blind, randomized controlled trial will aim to recruit 70 participants with heart failure. Participants will be randomized to either (1) standard training: combination of upper and lower extremity cardiovascular and resistance-based exercises, or (2) HISMT plus modified standard training: bilateral knee extensor HISMT and a modified version of the standard training, so that the total volume of work will be similar to standard training alone. The training interventions will be undertaken twice weekly for 12 weeks in an outpatient clinical setting. Outcome measurements will be performed at baseline and after the 12-week intervention period. The primary outcome will be exercise capacity (6-Minute Walk Test), with secondary outcomes being physical performance measures, muscle strength, and health-related quality of life. Data will be analyzed using the intention-to-treat principle.

IMPACT

This study will address a gap in the literature regarding the efficacy of small muscle training under routine clinical conditions for individuals with heart failure. The findings will also provide insight into the effects of HISMT within a heart failure rehabilitation program, thus enabling the optimization of exercise prescription for this patient population.

Determinants of maximal exercise performance in chronic heart failure

BACKGROUND

Chronic heart failure (CHF) is characterized by symptoms like fatigue, dyspnoea and limited exercise performance. It has been postulated that maximal exercise performance (Wmax) is predominantly limited by skeletal muscle function and less by heart function.

AIM

To study the interrelation between most relevant muscle and anthropometrical variables and Wmax in CHF patients in order to develop a model that describes the impact of these variables for maximal exercise performance.

DESIGN

In 77 patients with CHF Wmax was assessed by incremental cycle ergometry until exhaustion (20 Watt/3 min). Peak torque (strength) and total work (endurance) for the quadriceps and hamstrings were assessed by isokinetic dynamometry. Isometric strength was measured by hand dynamometry. Relevant muscle areas were calculated by computerized tomography scan.

RESULTS

Significant correlations between Wmax and isokinetic muscle parameters (peak torque and total work) ranged from 0.41-0.65 (P<0.01). Other significant relationships (P<0.01) with Wmax were obtained for age (r=-0.22), gender (r=0.45), fat free mass (FFM) (r=0.51), quadriceps muscle area (r=0.73), hamstrings muscle area (r=0.50), upper leg muscle function (i.e., a combination of muscle strength and muscle endurance) (r=0.71) and isometric strength (r=0.63). Multiple regression analysis showed that upper leg muscle function and quadriceps muscle area could predict 57% of the variance in Wmax.

CONCLUSION

Muscle strength and muscle endurance, combined with quadriceps muscle area are the main predictors of maximal exercise performance in patients with CHF.

Effects of Light Intensity Activity on CVD Risk Factors: A Systematic Review of Intervention Studies

The effects of light intensity physical activity (LIPA) on cardiovascular disease (CVD) risk factors remain to be established. This review summarizes the effects of LIPA on CVD risk factors and CVD-related markers in adults. A systematic search of four electronic databases (PubMed, Academic Search Complete, SPORTDiscus, and CINAHL) examining LIPA and CVD risk factors (body composition, blood pressure, glucose, insulin, glycosylated hemoglobin, and lipid profile) and CVD-related markers (maximal oxygen uptake, heart rate, C-reactive protein, interleukin-6, tumor necrosis factor-alpha, and tumor necrosis factor receptors 1 and 2) published between 1970 and 2015 was performed on 15 March 2015. A total of 33 intervention studies examining the effect of LIPA on CVD risk factors and markers were included in this review. Results indicated that LIPA did not improve CVD risk factors and CVD-related markers in healthy individuals. LIPA was found to improve systolic and diastolic blood pressure in physically inactive populations with a medical condition. Reviewed studies show little support for the role of LIPA to reduce CVD risk factors. Many of the included studies were of low to fair study quality and used low doses of LIPA. Further studies are needed to establish the value of LIPA in reducing CVD risk.

Exercise-resembling effects of periodic somatosensory stimulation in heart failure

BACKGROUND

The mechanism of the beneficial effects of exercise training on autonomic derangement and neurohumoral activation in chronic heart failure (CHF) is largely unexplained. In our here-presented hypothesis-generating study we propose that part of these effects is mediated by the exercise-accompanying somatosensory nerve traffic. To demonstrate this, we compared the effects of periodic electrical somatosensory stimulation in patients with CHF with the effects of exercise training and with usual care.

METHODS

In a randomized controlled study we measured, in CHF patients, changes in blood pressure, baroreflex sensitivity (BRS), neurohormones, exercise capacity and quality of life (QOL) in response to periodic somatosensory stimulation in the form of 2 Hz transcutaneous electrical nerve stimulation (TENS) at both feet, in response to conventional exercise training (EXTR) and, as control (CTRL), in patients with usual care only.

RESULTS

Group sizes were N=31 (TENS group), N=25 (EXTR group) and N=30 (CTRL group), respectively. Practically all improvements in BRS, neurohormone concentrations, exercise capacity and QOL in the TENS group were comparable to, or sometimes even better than in the EXTR group. These improvements were not observed in the CTRL group.

CONCLUSIONS

This study demonstrates that periodic electrical somatosensory stimulation is as effective as exercise training in improving BRS, neurohormone concentrations, exercise capacity and QOL in CHF patients. These results encourage exploration of exercise modalities that concentrate on rhythm rather than on effort, with the purpose to normalize autonomic derangement and neurohumoral activation in CHF.

Clinically meaningful change estimates for the six-minute walk test and daily activity in individuals with chronic heart failure

PURPOSE

The purpose of the present pilot study was to provide a preliminary estimate of the minimum detectable difference (MDD) and minimum clinically important difference (MCID) of the six-minute walk test (6MWT) and daily activity in outpatients with chronic heart failure (CHF).

METHODS

A convenience sample of 22 adults with stable New York Heart Association Functional Class II and III CHF performed two baseline 6MWTs separated by 30 minutes of rest. Subjects then wore a triaxial accelerometer for 7 days to monitor daily activity. After 7 weeks of usual care, subjects again wore the accelerometer for 7 days and then returned to the clinic to complete the Global Rating of Change Scale (GRS) with regard to their heart disease and perform another set of 6MWTs. For the 6MWT, the MDD was calculated using the two baseline 6MWT distances. For daily activity, the MDD was calculated using two methods: (1) day-to-day test-retest reliability during baseline monitoring, and (2) baseline to follow-up test-retest reliability in those who reported no change on the GRS. The MCID for the 6MWT and daily activity was calculated using the mean and 95% confidence interval (CI95%) for those subjects who reported 'improvement' on the GRS.

RESULTS

The MDD at the CI95% for the 6MWT was 32.4 meters. The MCID for the 6MWT was 30.1 (CI95% 20.8, 39.4) meters. The MDD for daily activity was 5,909 vector magnitude units (VMU·hr.(-1)) The MCID for daily activity was 1,337 VMU·hr.(-1) There was good alignment of the MDD and MCID for the 6MWT, suggesting that clinically meaningful change is approximately 32 meters. However, the calculated MCID was substantially less than measurement error as represented by the MDD, indicating that the MCID was underestimated in this sample or that daily activity may be robust to change in overall disease status.

Intrinsic skeletal muscle alterations in chronic heart failure patients: a disease-specific myopathy or a result of deconditioning?

Chronic heart failure (CHF) patients frequently experience impaired exercise tolerance due to skeletal muscle fatigue. Studies suggest that this in part is due to intrinsic alterations in skeletal muscle of CHF patients, often interpreted as a disease-specific myopathy. Knowledge about the mechanisms underlying these skeletal muscle alterations is of importance for the pathophysiological understanding of CHF, therapeutic approach and rehabilitation strategies. We here critically review the evidence for skeletal muscle alterations in CHF, the underlying mechanisms of such alterations and how skeletal muscle responds to training in this patient group. Skeletal muscle characteristics in CHF patients are very similar to what is reported in response to chronic obstructive pulmonary disease (COPD), detraining and deconditioning. Furthermore, skeletal muscle alterations observed in CHF patients are reversible by training, and skeletal muscle of CHF patients seems to be at least as trainable as that of matched controls. We argue that deconditioning is a major contributor to the skeletal muscle dysfunction in CHF patients and that further research is needed to determine whether, and to what extent, the intrinsic skeletal muscle alterations in CHF represent an integral part of the pathophysiology in this disease.

Developing the model of pulmonary rehabilitation for chronic heart failure

Patients with chronic obstructive pulmonary disease (COPD) and chronic heart failure (CHF) commonly suffer from exertional symptoms of breathlessness and fatigue. The similar systemic manifestations of the conditions, including skeletal muscle dysfunction, are a major contributing factor to the limitation in exercise capacity. A period of exercise training has been shown to improve exercise performance and health-related quality of life for both conditions. Exercise training is a key component of pulmonary rehabilitation (PR) which is now a standard of care for patients with COPD and is symptom based. Although it may be assumed that patients with CHF could be incorporated into cardiac rehabilitation, this is predominantly a secondary prevention programme for patients who are largely asymptomatic. It has been shown that patients with CHF can be successfully trained together with patients with COPD by the same therapists within PR. There are comparable outcome measures that can be used for both COPD and CHF. Many patients with CHF still do not have access to an exercise rehabilitation programme and incorporating them into the PR model of care could be one solution. This article reviews the (1) similar symptoms, mechanisms and consequences between COPD and CHF, (2) rationale and evidence for exercise training in CHF, (3) model of PR, (4) safety of exercise training in CHF, (5) evidence for combined exercise rehabilitation for CHF and COPD, (6) adaptations necessary to include patients with CHF into PR, (7) the chronic care model and (8) summary.

Clinical utility of exercise training in chronic systolic heart failure

The volume of literature attesting to the clinical benefits of exercise training in patients with stable chronic heart failure (CHF) is substantial. Training can improve symptoms and exercise capacity, as well as reducing morbidity, mortality, and rates of emergency hospitalization. These benefits are apparent in all patients with stable CHF, irrespective of age or sex, or the etiology or severity of heart failure. Training regimens for patients with stable, systolic CHF should form part of a comprehensive heart-failure support effort and are best delivered using supervised in-hospital exercise combined with some training at home or in a group setting in community centers. In this Review, the modes and intensity of exercise training, selection of patients, duration of training effects, and other clinical guidance for using this treatment option are discussed.

A randomized trial of the addition of home-based exercise to specialist heart failure nurse care: the Birmingham Rehabilitation Uptake Maximisation study for patients with Congestive Heart Failure (BRUM-CHF) study

AIMS

Supervised exercise can benefit selected patients with heart failure, however the effectiveness of home-based exercise remains uncertain. We aimed to assess the effectiveness of a home-based exercise programme in addition to specialist heart failure nurse care.

METHODS AND RESULTS

This was a randomized controlled trial of a home-based walking and resistance exercise programme plus specialist nurse care (n=84) compared with specialist nurse care alone (n=85) in a heart failure population in the West Midlands, UK.

PRIMARY OUTCOME

Minnesota Living with Heart Failure Questionnaire (MLwHFQ) at 6 and 12 months.

SECONDARY OUTCOMES

composite of death, hospital admission with heart failure or myocardial infarction; psychological well-being; generic quality of life (EQ-5D); exercise capacity. There was no statistically significant difference between groups in the MLwHFQ at 6 month (mean, 95% CI) (-2.53, -7.87 to 2.80) and 12 month (-0.55, -5.87 to 4.76) follow-up or secondary outcomes with the exception of a higher EQ-5D score (0.11, 0.04 to 0.18) at 6 months and lower Hospital Anxiety and Depression Scale score (-1.07, -2.00 to -0.14) at 12 months, in favour of the exercise group. At 6 months, the control group showed deterioration in physical activity, exercise capacity, and generic quality of life.

CONCLUSION

Home-based exercise training programmes may not be appropriate for community-based heart failure patients.

A Systematic Review of Exercise Interventions in Patients With Heart Failure

The incidence of heart failure (HF) is increasing as the population ages. Pharmacotherapy is an important component of treatment and yields significant improvements in survival and quality of life. In recent decades, exercise has gradually become accepted as an intervention beneficial to patients with HF, but more information is needed to clarify the effects of exercise and optimize interventions. Therefore, a systematic review of randomized controlled trials published from 1966 to October 2006 was carried out via PubMed. About 69 trials were reviewed, which used as main outcome measures: (a) central hemodynamic parameters, (b) peripheral blood flow, (c) endothelial function, (d) activation of neurohormones and cytokine systems, (e) structure of and metabolism in skeletal muscles, and/or (f) quality of life. Study findings suggest that the favorable physiological responses to exercise might slow some of the pathophysiological progression of HF. However, most of the trials reviewed here were based on relatively small samples and selected participant groups, and the exercise programs varied widely. These limitations and inconsistencies need to be addressed through further studies. Furthermore, reliable strategies for maintaining the positive effects of exercise and extending them to patients' daily life and quality of life are scarce in these trials. These domains need further exploration through rationally designed, large-scale randomized controlled trials.

Implications of chronic heart failure on peripheral vasculature and skeletal muscle before and after exercise training

The pathophysiology of chronic heart failure (CHF) is typically conceptualized in terms of cardiac dysfunction. However, alterations in peripheral blood flow and intrinsic skeletal muscle properties are also now recognized as mechanisms for exercise intolerance that can be modified by therapeutic exercise. This overview focuses on blood delivery, oxygen extraction and utilization that result from heart failure. Related features of inflammation, changes in skeletal muscle signaling pathways, and vulnerability to skeletal muscle atrophy are discussed. Specific focus is given to the ways in which perfusion and skeletal muscle properties affect exercise intolerance and how peripheral improvements following exercise training increase aerobic capacity. We also identify gaps in the literature that may constitute priorities for further investigation.

Effect of exercise training on autonomic derangement and neurohumoral activation in chronic heart failure

BACKGROUND

In chronic heart failure (CHF), persistent autonomic derangement and neurohumoral activation cause structural end-organ damage, decrease exercise capacity, and reduce quality of life. Beneficial effects of pharmacotherapy and of exercise training in CHF have been documented at various functional and structural levels. However, pharmacologic treatment can not yet reduce autonomic derangement and neurohumoral activation in CHF to a minimum. Various studies suggest that exercise training is effective in this respect.

METHODS AND RESULTS

After reviewing the available evidence we conclude that exercise training increases baroreflex sensitivity and heart rate variability, and reduces sympathetic outflow, plasma levels of catecholamines, angiotensin II, vasopressin, and brain natriuretic peptides at rest.

CONCLUSIONS

Exercise training has direct and reflex sympathoinhibitory beneficial effects in CHF. The mechanism by which exercise training normalizes autonomic derangement and neurohumoral activation is to elucidate for further development of CHF-related training programs aimed at maximizing efficacy while minimizing workload.

Central haemodynamics and peripheral muscle function during exercise in patients with chronic heart failure

In this narrative review of the current literature, we examine the central and peripheral mechanisms responsible for the exercise intolerance of chronic heart failure and highlight briefly the benefits of exercise training in the treatment of this debilitating disorder. Specifically, we identify the common finding of reduced cardiac output reserve during exercise conditions leading to decreased exercise tolerance. We also reveal that the stroke volume response to exercise varies depending on the individual patient, the presence of mitral regurgitation, and the aetiology of heart failure. Chronic heart failure patients with left ventricular systolic dysfunction appear able to use the Frank-Starling mechanism to compensate (in part) for their decreased contractile reserve. Patients with left ventricular diastolic dysfunction have normal contractile function; however, they are unable to make use of the Frank-Starling mechanism during exercise conditions. We also reveal that pericardial constraint may limit diastolic filling and exercise capacity in patients with chronic heart failure. It appears that interventions that reduce pericardial constraint and mitral regurgitation enhance diastolic filling and increase exercise tolerance. A series of peripheral muscle changes also occur, including changes in muscle mass, cellular structure, energy metabolism, and blood flow. Each of these factors is associated with decreased exercise capacity and the symptoms of chronic heart failure. Exercise training has been shown to improve both central haemodynamics and peripheral muscle function leading to improvements in exercise capacity, functional status, and overall quality of life in patients with chronic heart failure.

Exercise training in heart failure

The reduction of exercise capacity with early occurrences of fatigue and dyspnea is a hallmark of heart failure syndrome. There are objective similarities between heart failure and muscular deconditioning. Deficiencies in peripheral blood flow and skeletal muscle function, morphology, metabolism, and function are present. The protective effects of physical activity have been elucidated in many recent studies: training improves ventilatory control, skeletal muscle metabolism, autonomic nervous system, central and peripheral circulation, and heart function. These provide the physiologic basis to explain the benefits in terms of survival and freedom from hospitalization demonstrated by physical training in heart failure.

Study protocol to investigate the effects of testosterone therapy as an adjunct to exercise rehabilitation in hypogonadal males with chronic heart failure

Background

Testosterone deficiency is a common occurrence in men with chronic heart failure (CHF) and may underpin features of advanced disease, including reduced skeletal muscle mass and fatigue. It is positively correlated with cardiac output and exercise capacity in patients with CHF, whereas a significant improvement in both these parameters has been observed following testosterone replacement therapy. Testosterone therapy has also been shown to reduce circulating levels of inflammatory markers, (TNF-α, sICAM-1 and sVCAM-1) in patients with established coronary artery disease and testosterone deficiency. This pilot study will assess the feasibility of a combined exercise rehabilitation and adjunctive testosterone therapy intervention for evoking improvements in exercise capacity, circulating inflammatory markers, cardiac and skeletal muscle function, indices of psychological health status and quality of life in hypogonadal males with chronic heart failure.

Methods/design

Following ethical approval, 36 patients will be randomly allocated to one of two groups: testosterone or placebo therapy during exercise rehabilitation. A combined programme of moderate intensity aerobic exercise and resistance (strength) training will be used. The primary outcome measure is exercise capacity, assessed using an incremental shuttle walk test. Secondary outcome measures include measures of peak oxygen uptake, cardiac function, lower-limb skeletal muscle contractile function and oxygenation during exercise, circulating inflammatory markers, psychological health status and quality of life.

Discussion

Exercise rehabilitation can safely increase exercise capacity in stable CHF patients but there is a need for studies which are aimed at evaluating the long-term effects of physical training on functional status, morbidity and mortality. This pilot study will provide valuable preliminary data on the efficacy of testosterone therapy as an adjunct to exercise rehabilitation on a range of functional, physiological and health-related outcomes in this patient population. Preliminary data will be used in the design of a large-scale randomised controlled trial, aimed at informing clinical practice with respect to optimisation of exercise rehabilitation in this patient group.

[Exercise training in cardiac patients: usefulness of the cardiopulmonary exercise test]

Exercise training is currently including in the treatment of coronary arterial disease patients, in patients with left ventricular dysfunction as well as in patients who underwent cardiac transplantation or cardiac surgery. However methods of prescribing exercise-training programs are difficult to determine and must be adapted for each patient Exercise test with gas analysis through the determination of anaerobic threshold may help to understand the physiopathological mechanism related to exercise limitation in these patients. Exercise test may help to precise exercise intensity during cardiac rehabilitation and may assess the benefits on exercise tolerance.

Evidence for prescribing exercise as therapy in chronic disease

Considerable knowledge has accumulated in recent decades concerning the significance of physical activity in the treatment of a number of diseases, including diseases that do not primarily manifest as disorders of the locomotive apparatus. In this review we present the evidence for prescribing exercise therapy in the treatment of metabolic syndrome-related disorders (insulin resistance, type 2 diabetes, dyslipidemia, hypertension, obesity), heart and pulmonary diseases (chronic obstructive pulmonary disease, coronary heart disease, chronic heart failure, intermittent claudication), muscle, bone and joint diseases (osteoarthritis, rheumatoid arthritis, osteoporosis, fibromyalgia, chronic fatigue syndrome) and cancer, depression, asthma and type 1 diabetes. For each disease, we review the effect of exercise therapy on disease pathogenesis, on symptoms specific to the diagnosis, on physical fitness or strength and on quality of life. The possible mechanisms of action are briefly examined and the principles for prescribing exercise therapy are discussed, focusing on the type and amount of exercise and possible contraindications.

Effects of exercise training on cardiac performance, exercise capacity and quality of life in patients with heart failure: a meta-analysis

BACKGROUND

Despite major advances in pharmacological treatment of chronic heart failure (CHF), a number of patients still suffer from dyspnoea, fatigue, diminished exercise capacity and poor quality of life. It is in this context that exercise training is being intensively evaluated for any additional benefit in the treatment of CHF.

AIMS

To determine the effect of exercise training in patients with CHF on cardiac performance, exercise capacity and health-related quality of life. A meta-analysis was performed to obtain this goal.

METHODS AND RESULTS

After including 35 randomised controlled trials, the methodological quality of each study was assessed, summary effect sizes (SESs) and the concomitant 95% confidence intervals (95% CI) were calculated for each outcome. Quantitative analysis showed statistically significant SESs, at rest, for diastolic blood pressure and end-diastolic volume. During maximal exercise, significant SESs were found for systolic blood pressure, heart rate, cardiac output, peak oxygen uptake, anaerobic threshold and 6-min walking test. The Minnesota Living with Heart Failure Questionnaire improved by an average of 9.7 points.

CONCLUSIONS

Exercise training has clinically important effects on exercise capacity and HRQL, and may have small positive effects on cardiac performance during exercise.

Maximum oxygen uptake corrected for skeletal muscle mass accurately predicts functional improvements following exercise training in chronic heart failure

BACKGROUND

Skeletal muscle mass and peak oxygen uptake are important predictors of functional status and outcome in patients with stable chronic heart failure.

AIMS

To assess changes in skeletal muscle mass and peak oxygen uptake following an exercise training program.

METHODS

Thirty-six patients with moderate stable chronic heart failure were randomly allocated to either a bicycle ergometer (bike) or functional electrical muscle stimulators (FES) applied to quadriceps and gastrocnemius muscles to be used daily for six weeks. Dual-energy X-ray absorptionometry (DEXA) scanning was performed before and after training along with symptom limited cardiopulmonary exercise test, quadriceps strength and fatigue resistance, and 6-min walk test.

RESULTS

Both exercise modalities resulted in improvements in treadmill exercise time, leg strength, 6-min walk test and peak oxygen uptake per kilogram of skeletal muscle. Despite significant improvements in functional capacity, there were no significant changes in body composition for total skeletal muscle mass, leg muscle mass or total body fat content. Skeletal muscle mass was strongly predictive of maximum oxygen uptake at baseline (r=0.61, p<0.001) and after exercise training (r=0.68, p<0.001).

CONCLUSIONS

In moderate stable chronic heart failure, exercise training using bicycle ergometer or FES results in favourable qualitative rather than quantitative changes in skeletal muscle. Correction of maximum oxygen uptake for skeletal muscle mass rather than total body mass is a more sensitive measure of changes associated with exercise training.

Exercise training in heart failure

The reduction of exercise capacity with early occurrence of fatigue and dyspnea is a hallmark of heart failure syndrome. There are objective similarities between heart failure and muscular deconditioning. Deficiencies in peripheral blood flow and skeletal muscle function, morphology, metabolism, and function are present. The protective effects of physical activity have been elucidated in many recent studies: training improves ventilatory control, skeletal muscle metabolism, autonomic nervous system, central and peripheral circulation, and heart function. These provide the physiologic basis to explain the benefits in terms of survival and freedom from hospitalization demonstrated by physical training also in heart failure.

The effect of physical training on workload, upper leg muscle function and muscle areas in patients with chronic heart failure

OBJECTIVE

To investigate the effect of physical training (PTr) on upper leg muscle area, muscle strength and muscle endurance expressed as upper leg muscle function (ULMF) in relation to exercise performance in CHF.

DESIGN

Randomised to a training (TG) or control group (CG).

SETTING

Outpatient cardiac rehabilitation centre of community hospital.

PATIENTS

77 CHF patients (59 men and 18 women), NYHA class II/III, age 59.8+/-9.3 years, LVEF 27+/-8%. Sixteen patients dropped out during the intervention period, 61 patients (M/F:46/15) completed the study.

INTERVENTION

PTr (combined strength and endurance exercises) four times per week, twice supervised and twice at home, during 26 weeks.

MAIN OUTCOME MEASURES

LVEF, body composition, daily physical activity, exercise performance, upper leg muscle area and isokinetic leg muscle variables.

RESULTS

Workload and peak oxygen consumption decreased in the CG (-4.1% and -4%) but increased in the TG (+5% and +4%) following PTr (p<0.05, ANOVA repeated measures). Hamstrings area decreased in the CG and did not change in the TG (p<0.05, ANOVA repeated measures). ULMF improved in the TG, but remained unchanged in the CG (+13.0% and 0.0, respectively, p<0.05; ANOVA repeated measures). At baseline and after intervention nearly 60% of the variance in maximal workload was explained by ULMF and quadriceps muscle area (multiple regression analysis).

CONCLUSIONS

In CHF patients, home-based training in conjunction with a supervised strength and endurance training program is safe, feasible and effective and does not require complex training equipment. Physical training prevented loss of hamstrings muscle mass and improved exercise performance by enhancing muscle strength and endurance.

Outcome of exercise training on the long-term burden of hospitalisation in patients with chronic heart failure. A retrospective study

AIMS

Heart failure is a major cause of hospitalisation, particularly in patients more than 65 years of age in the western world. A common endpoint in studies designed to evaluate treatment effects in heart failure is mortality and morbidity, often reported as an event of hospitalisation. It has recently been reported that this endpoint is misleading with respect to the burden of the disease with regard to the patient, the health service and costs. Furthermore, it can be hypothesized that different treatment effects are better evaluated using more sensitive parameters than those traditionally used in clinical studies. Short-term beneficial effects of exercise training in heart failure patients have previously been showed. Therefore, the aim of this study was to evaluate the long-term effects of exercise training in heart failure patients with regard to different outcome parameters. METHOD AND STUDY GROUP: Patients with chronic heart failure, stabilised on pharmacological treatment, who had participated in a physical training program for 8 weeks, were analysed retrospectively after 5 years. The study group was compared to a matched control group which received conventional treatment and was diagnosed during the same period but not participating in a training program.

RESULTS

Exercise training in heart failure patients resulted in significantly less hospitalisation events (2+/-3 vs. 3+/-3, p<0.05) and hospitalisation days (10+/-17 vs. 20+/-27, p<0.05) due to cardiac problems at 5 years after follow-up. Exercise training did not effect mortality.

CONCLUSION

Long-term effects of exercise training on burden of disease in chronic heart failure patients is associated with significantly less events and days of hospitalisation due to worsening of cardiac disease.

Exercise training in heart failure

The reduction of exercise capacity with early occurrence of fatigue and dyspnea is a hallmark of heart failure syndrome. There are objective similarities between heart failure and muscular deconditioning. Deficiencies in peripheral blood flow and skeletal muscle function, morphology, metabolism, and function are present. The protective effects of physical activity have been elucidated in many recent studies: training improves ventilatory control, skeletal muscle metabolism, autonomic nervous system, central and peripheral circulation, and heart function. These provide the physiologic basis to explain the benefits in terms of survival and freedom from hospitalization demonstrated by physical training also in heart failure.

Réadaptation physique des patients insuffisants cardiaques chroniques

A BENEFICIAL METHOD: Heart failure combines with peripheral vascular and muscular abnormalities that can be effectively improved by rehabilitation. The data in the literature appears to demonstrate the efficacy and excellent tolerance of such exercise. Regarding functional results and improved quality of life, rehabilitation is as equally efficient as the medical treatment that it completes. It can currently be proposed to the majority of patients exhibiting left ventricular systolic dysfunction and who are are only partially improved with medical treatment alone. MODALITIES: The rehabilitation of heart failure must, optimally, be set-up in ambulatory settings, notably within the context of a health care network. Its modalities remain to be specified in on-going studies and its impact on prognosis has to be determined.

The role of exercise training in patients with chronic heart failure

The National Institute for Clinical Excellence (NICE) has recommended that exercise training be offered to patients with chronic heart failure (CHF). This recommendation is supported by research-based evidence from a variety of studies over the past 10 years. Initially, the studies were concerned primarily with the safety and effectiveness of exercise in these high-risk patients, but more recent studies have begun to investigate the most appropriate methods of exercise for this patient population. This article presents a systematic review of the literature relating to exercise training and CHE. It then attempts to identify, in light of the evidence, the most effective programme of exercise, including type, duration and degree of exercise. Finally, it discusses practical application and implementation of the research findings into everyday health care, including issues such as staff development and training, assessment, exercise and prescription for individual patients, and evaluation of the service.

Exercise training for patients with heart failure: a systematic review of factors that improve mortality and morbidity

PURPOSE

To determine the efficacy of exercise training and its effects on outcomes in patients with heart failure.

METHODS

MEDLINE, Medscape, and the Cochrane Controlled Trials Registry were searched for trials of exercise training in heart failure patients. Data relating to training protocol, exercise capacity, and outcome measures were extracted and reviewed.

RESULTS

A total of 81 studies were identified: 30 randomized controlled trials, five nonrandomized controlled trials, nine randomized crossover trials, and 37 longitudinal cohort studies. Exercise training was performed in 2387 patients. The average increment in peak oxygen consumption was 17% in 57 studies that measured oxygen consumption directly, 17% in 40 studies of aerobic training, 9% in three studies that only used strength training, 15% in 13 studies of combined aerobic and strength training, and 16% in the one study on inspiratory training. There were no reports of deaths that were directly related to exercise during more than 60,000 patient-hours of exercise training. During the training and follow-up periods of the randomized controlled trials, there were 56 combined (deaths or adverse events) events in the exercise groups and 75 combined events in the control groups (odds ratio [OR] = 0.98; 95% confidence interval [CI]: 0.61 to 1.32; P = 0.60). During this same period, 26 exercising and 41 nonexercising subjects died (OR = 0.71; 95% CI: 0.37 to 1.02; P = 0.06).

CONCLUSION

Exercise training is safe and effective in patients with heart failure. The risk of adverse events may be reduced, but further studies are required to determine whether there is any mortality benefit.

Therapeutic exercise for individuals with heart failure: special attention to older women with heart failure

BACKGROUND

A cardinal feature of heart failure (HF) is the reduced peak aerobic power (VO(2peak)) secondary to alterations in cardiovascular and musculoskeletal function. Methods and results During the last decade, a number of randomized trials have examined the role that exercise training plays in attenuating the HF-mediated decline in VO(2peak) and muscle strength. The major finding of these investigations was that aerobic or strength training was an effective intervention to increase VO(2peak), muscular strength, distance walked in 6 minutes, and quality of life without negatively altering left ventricular systolic function. Despite these benefits, a limitation of these investigations was the primary focus on males <60 years with impaired left ventricular systolic function. Thus the role that exercise training may play in attenuating the HF-mediated decline in VO(2peak) in women > or =65 years of age remains unknown.

CONCLUSION

Older women with HF have a VO(2peak) that is below the minimal threshold level required for independent living. Moreover, older women with HF have greater disability then men and are less likely to be referred to an exercise rehabilitation program. Accordingly, future exercise intervention trials are required to examine the role that exercise training may play in attenuating the HF-mediated decline in cardiorespiratory and musculoskeletal fitness and disability in older women with HF.

[Strength training with elastic bands: measure of its effects in cardiac rehabilitation after coronary diseases]

OBJECTIVES

To compare high intensity strength training with weightlifting exercises or with elastic bands.

SETTING

Outpatient unit of cardiac rehabilitation. TYPE: Prospective randomised clinical trial.

POPULATION

Inclusion of coronary patients in phase II after medical or surgical treatment of a myocardiac infarction, without cardiac insufficiency; beta-blockers were accepted.

METHOD

Evaluation of coronary patients at beginning and at the end of a 4 week cardiac rehabilitation program. It included progressive aerobic training according to Karvonen method for all the patients, associated with weightlifting exercises (Koch press) in the control group, or use of elastic bands in the experimental group. Cardiac rate, oxygen consumption at rest and at maximum power were the main criteria with also muscle strength of quadriceps, hamstrings, biceps brachii, latissimus dorsi and triceps brachii, body mass indexes, quality of life with SF-36, anxiety (stay T test) and perceived exertion with the Borg 10-point category-ratio scale, myotendinous injuries (Shaw scale).

RESULTS

Twenty-six coronary patients, all male from 45 to 65 years old, all receiving beta-blockers, were included, 13 in each group. Control and experimental groups were initially similar. At the end of the 4 week program, all the two groups improved significantly their strength and power and there were no differences between the two groups. Perceived exertion was lower in the group using elastic bands and there were no myotendinous lesions.

CONCLUSION

Strength training with elastic bands is a low-cost, attractive, playful technique, proposed to a group of coronary patients, which appears as effective in cardiac rehabilitation as individual weightlifting training.

Exercise based rehabilitation for heart failure

BACKGROUND

The prevalence of chronic heart failure is increasing, and increases with increasing age. Major symptoms include breathlessness and restricted activities of daily living due to reduced functional capacity, which in turn affects quality of life. Exercise training has been shown to be effective in patients with coronary heart disease and has been proposed as an intervention to improve exercise tolerance in patients with heart failure.

OBJECTIVES

To determine the effectiveness of exercise based interventions compared with usual medical care on the mortality, morbidity, exercise capacity and health related quality of life, of patients with heart failure.

SEARCH STRATEGY

We searched the Cochrane Controlled Trials Register (The Cochrane Library Issue 2, 2001), MEDLINE (2000 to March 2001), EMBASE (1998 to March 2001), CINAHL (1984 to March 2001) and reference lists of articles. We also sought advice from experts.

SELECTION CRITERIA

RCTs of exercise based interventions. The comparison group was usual medical care as defined by the study, or placebo. Adults of all ages with chronic heart failure. Only those studies with criteria for diagnosis of heart failure (based on clinical findings or objective indices) have been included.

DATA COLLECTION AND ANALYSIS

Studies were selected, and data were abstracted, independently by two reviewers. Authors were contacted where possible to obtain missing information.

MAIN RESULTS

Twenty-nine studies met the inclusion criteria, with 1126 patients randomised. The majority of studies included both patients with primary and secondary heart failure, NYHA class II or III. None of the studies specifically examined the effect of exercise training on mortality and morbidity as most were of short duration. Exercise training significantly increased VO(2) max by (WMD random effects model) 2.16 ml/kg/min (95% CI 2.82 to 1.49), exercise duration increased by 2.38 minutes (95% CI 2.85 to 1.9), work capacity by 15.1 Watts (95% CI 17.7 to 12.6) and distance on the six minute walk by 40.9 metres (95% CI 64.7 to 17.1). Improvements in VO(2) max were greater for training programmes of greater intensity and duration. HRQoL improved in the seven of nine trials that measured this outcome.

REVIEWERS' CONCLUSIONS

Exercise training improves exercise capacity and quality of life in patients mild to moderate heart failure in the short term. There is currently no information regarding the effect of exercise training on clinical outcomes. The findings are based on small-scale trials in patients who are unrepresentative of the total population of patients with heart failure. Other groups (more severe patients, the elderly, women) may also benefit. Large-scale pragmatic trials of exercise training of longer duration, recruiting a wider spectrum of patients are needed to address these issues.

Differential effects of exercise training in men and women with chronic heart failure

BACKGROUND

Abnormalities of myosin heavy chain (MHC) isoforms, enzyme activity, and capillarity contribute to the exercise intolerance that is characteristic of patients with heart failure. To what extent these changes can be reversed with exercise training and whether differences exist in the responses of men and women remains uncertain. We described and compared the effects of exercise training on exercise capacity and skeletal muscle histochemistry in men and women with chronic heart failure.

METHODS

Fifteen patients (10 male) undergoing standard medical therapy completed a 14- to 24-week exercise training program. Peak oxygen consumption, MHC isoforms, capillary density, and selected metabolic enzymes were assessed before and after training.

RESULTS

Peak oxygen consumption was improved 14% (P <.05); however, this increase was mostly because of the improvement observed in men versus women (+20% versus +2%, respectively, P <.01). At baseline, MHC I content was lower in men than in women (33% +/- 3% vs 49.6% +/- 5.5%, P <.05). MHC I improved with training in men, to 45.6% +/- 4.5% (+38%, P <.05), versus women (-3%, P =.82), and the increase in men tended (P =.12) to be significant when compared with that in women. There were no significant changes in capillary density or muscle enzyme activity with training in the group as a whole or in men and women separately.

CONCLUSION

Among patients with chronic heart failure, improvements in peak exercise capacity may be more pronounced in men than in women. This difference in response of functional capacity to training paralleled differences observed between men and women for changes in MHC I isoforms.

Relationship between the Minnesota Living With Heart Failure Questionnaire and key ventilatory expired gas measures during exercise testing in patients with heart failure

PURPOSE

This study assessed the relationship between the Minnesota Living With Heart Failure Questionnaire (MLWHFQ) and key ventilatory expired gas measures during a symptom-limited exercise test in the heart failure (HF) population. Specifically, is there evidence to indicate that perceived quality of life (QOL) influences exercise performance independent of physiologic function in the HF population?

METHODS

Thirty-one subjects (21 male/10 female), diagnosed with compensated HF, underwent exercise testing and completed the MLWHFQ. Mean age and left ventricular ejection fraction were 52.8 years and 27.2%, respectively. Partial correlation, controlling for age and sex, assessed the relationship between MLWHFQ (overall and subscores) and key ventilatory expired gas measures. Intraclass correlation coefficient (ICC) analysis was used to determine reliability of the MLWHFQ.

RESULTS

MLWHQ overall score (mean = 38.9, median = 36.0), physical subscore (mean = 14.8, median = 16.0), and psychosocial/symptomatology subscore (mean = 24.1, median = 19.0), were significantly correlated (P < or =.05) with peak oxygen consumption (VO2). The relationship between MLWHFQ and the minute ventilation-carbon dioxide production (VE/VCO2) slope was, however, not significant. ICC analysis revealed high reliability (0.95) for the MLWHFQ.

CONCLUSIONS

The MLWHFQ demonstrates a significant relationship with peak VO2, a measure whose validity is dependent upon subject effort. VE/VCO2 slope, which is independent of subject effort and therefore potentially a better predictor of true physiologic function, does not appear to have a relationship with perceived QOL. These findings have implications for how the MLWHFQ is assessed, related to an exercise test, and used during clinical practice.

Skeletal muscle training in chronic heart failure

Patients with heart failure are limited in their ability to tolerate exercise. Recent research has suggested that this limitation cannot be entirely attributed to cardiac or lung impairment but rather that changes in peripheral muscles may play an important role. There are objective similarities between heart failure and muscular deconditioning. Deficiencies in peripheral blood flow and skeletal muscle function, morphology, metabolism and function are present in both conditions. Moreover, an exaggerated activity of the receptors sensitive to exercise-derived metabolic signals (muscle ergoreceptors and peripheral and central chemoreceptors) leads to early and profound exercise-induced fatigue and dyspnoea. These muscle afferents contribute to the ventilatory, haemodynamic and autonomic responses to exercise both in physiological and pathological conditions, including chronic heart failure. Against this background, a skeletal muscle origin of symptoms in heart failure has been proposed. The protective effects of physical training have been described in many recent studies: training improves ventilatory control, skeletal muscle metabolism and autonomic nervous system activity. The exercise training appears to induce its beneficial effects on skeletal muscle both directly (on muscle function, histological and biochemical features) and indirectly (by reducing the activation of the muscle afferents). The metabolic mediators of these muscle afferents may become a potential target in the future therapy of heart failure symptoms.

Safety and efficacy of exercise training in a patient awaiting heart transplantation while on positive intravenous inotropic support

The safety and efficacy of exercise training in patients with congestive heart failure (CHF) is well established; however, the impact that exercise has on the subgroup of CHF patients awaiting heart transplant while on intravenous positive inotropic support remains largely unreported. This case study describes the safety and efficacy of exercise training in a patient awaiting heart transplant while on intravenous milrinone. Over a 1.2-year period, 246 exercise sessions were conducted with a total of 180.15 hours of aerobic exercise. During that time, the patient experienced only one hypotensive episode during exercise and had no other adverse events. The patient demonstrated a 38% increase in aerobic exercise time and a 34% increase in sustainable exercise workload. Research is needed to demonstrate the positive impact of exercise training on this subgroup of CHF patients.

The effect of physical training on skeletal muscle in patients with chronic heart failure

BACKGROUND

The improvement of exercise capacity in patients with chronic heart failure (CHF) by physical training has been connected with reversal of the abnormalities in muscle fiber distribution and with the reduced activity of the enzymes of oxidative metabolism in skeletal muscle. However, the change in fiber type distribution induced by training is controversial and in previous studies the activities of the rate-limiting enzymes of the metabolic pathways have not been measured.

AIMS

To examine the effect of dynamic training on percentage distribution of muscle fibers, on activities of the rate-limiting enzymes of the metabolic pathways and on electrophysiology in skeletal muscle.

METHODS

A total of 27 patients with stable CHF (NYHA class II-III) were randomized to a training (N=12) or a control (N=15) group. The training group exercised on a bicycle ergometer for 30 min three times a week for 3 months using a load corresponding to 50-60% of their peak oxygen consumption. This was followed by a 3-month training period at home according to personal instructions. The control group did not change its physical activities. We studied muscle histology and measured the activities of the rate-limiting enzymes of anaerobic glycolysis (phosphofructokinase, PFK), glycogenolysis (phosphorylase), citric acid cycle (alpha-ketoglurate dehydrogenase, KGDH) and fatty acid oxidation (carnitinepalmitoyl transferase I and II, CPT I and II) from biopsies of the vastus lateralis muscle at baseline and after 3 and 6 months. Muscle strength and strength endurance with surface EMG and macro EMG of the right knee extensors were also determined.

RESULTS

Exercise capacity, particularly submaximal, improved in the training group. The activity of PFK rose significantly but that of the other enzymes did not when compared with the change in the controls. Training had no effect on the percentage distribution of slow-twitch and fast-twitch muscle fibers or on capillary density around these fibers in skeletal muscle. Maximum voluntary force, strength endurance and the function of motor units remained unaffected.

CONCLUSIONS

Dynamic training results in improved exercise endurance in CHF. In skeletal muscle, the capacity of anaerobic glycolysis is increased but that of the citric acid cycle and fatty acid oxidation is not. Furthermore, the improvement in exercise endurance seems to be independent of changes in the percentage distribution of muscle fibers, capillarity or electrophysiological factors.

Clinical predictors of morbidity and mortality in patients with myocardial infarction or revascularization who underwent cardiac rehabilitation, and importance of diabetes mellitus and exercise capacity

This investigation was a prospective, follow-up study to assess whether baseline clinical and investigational parameters were predictors of cardiovascular morbidity and mortality in patients enrolled into the cardiac rehabilitation program. A cohort of 418 patients (70% were men) with coronary heart disease was followed up 3.2 +/- 1.1 years. Two hundred twenty-seven of them (54%) had a recent myocardial infarction (MI), with a thrombolytic rate of 54%. Percutaneous transluminal coronary angioplasty (PTCA) was performed in 45% of patients. The covariates assessed include age, gender, smoking habit, body mass index, the presence of hypertension or diabetes mellitus, exercise habit, site and severity of MI, status of thrombolytic therapy, peak creatine phosphokinase, plasma lipid profiles, ejection fraction, PTCA performed, number of diseased coronary arteries, and exercise capacity. Low-density lipoprotein cholesterol decreased significantly (3.2 +/- 1.0 vs 2.7 +/- 0.7 mmol/L, p < 0.001). The cumulative mortality was 13%. In a univariate model, the parameters that significantly predict mortality included older age, diabetes, low exercise capacity (< or = 4 metabolic equivalents) 3-vessel disease, those without PTCA performed, and a low ejection fraction. In the Cox proportional-hazards model analysis, the independent factors were coexisting diabetes (chi-square 6.1, p = 0.01) and a low metabolic equivalent (chi-square 6.5, p = 0.01). One hundred six patients were rehospitalized for nonfatal cardiovascular events that included unstable angina (48%), heart failure (21%), acute MI (6%), symptomatic arrhythmia (6%), and severe hypertension (1%). Factors that independently predicted rehospitalization were low exercise capacity (p = 0.02) and the presence of diabetes (chi-square 4.8, p = 0.03). Diabetes was also associated with more episodes of hospital admission (2.3 +/- 2.1 vs 1.6 +/- 1.4, p = 0.04) and a longer cumulative hospital stay (25.5 +/- 34.6 vs 11.4 +/- 19.6 days, p = 0.02). Thus, in patients with MI or after PTCA receiving conventional medical therapy, the cardiac rehabilitation program should focus on aggressive diabetic control and enhancement of exercise capacity.

Beneficial effects of exercise training in heart failure patients with low cardiac output response to exercise - a comparison of two training models

BACKGROUND

Exercise capacity of patients with chronic heart failure (CHF) correlates poorly with estimates of cardiac function. Yet, it has been suggested that only patients without severely impaired cardiac output (CO) benefit from exercise training. Comparisons of different training models have not been made in the same study.

AIMS

To evaluate whether the response to different training models diverges according to the cardiac output response to exercise in patients with chronic heart failure.

METHODS

Sixteen CHF patients (63 +/- 11 years) with an ejection fraction of 30 +/- 11% underwent a baseline cardiopulmonary exercise test, right heart catheterization and leg muscle biopsy. Cardiac output (CO) response to exercise was defined as the ratio between CO increase and the increase in oxygen uptake (CO response index) during exercise. Patients were randomized into two training regimens, differing with regard to active muscle mass, i.e. whole body and one-legged exercise.

RESULTS

Baseline exercise capacity expressed as W kg-1 correlated with the CO response index (r = 0.51, P < 0.05). Exercise capacity on the cycle ergometer increased in both groups but more in the one-legged than in the two-legged training group (P < 0.05). The improvement in exercise capacity did not correlate with base-line exercise capacity. It correlated with CO response index in the one-legged (r = 0.75, P < 0.01) but not in the two-legged training group. CO response index correlated negatively with the pulmonary capillary wedge pressure at peak exercise (r = - 0.60, P < 0.05). The increase in leg muscle citrate synthase activity after training correlated negatively with the baseline CO response index (r = - 0. 50, P < 0.05).

CONCLUSIONS

The improvement of exercise capacity after one-legged training correlates with the CO increase in relation to the O2 uptake before training. In patients with low CO response, individualization of the exercise regimen is needed and the benefits of training a limited muscle mass at a time deserve further study.

Home-based leg strengthening for older adults initiated through private practice

BACKGROUND

Leg strength correlates with functional ability in the frail elderly, many of whom can be reached through a private practice setting. The purpose of this study was to demonstrate the feasibility of physician-prescribed, home-based, clinic-monitored, high-intensity leg-strengthening treatment among elderly patients with a variety of medical problems.

METHODS

Twenty-two elderly patients with a variety of chronic medical conditions were invited to participate during regularly scheduled office visits if they had difficulty rising from a chair and an unsteady, cautious gait (age 85.1 +/- 5.7, 14 female). Physical therapists (PT) instructed patients to lift ankle weights at home, three times per week. Patients visited PT five times over a 12-week period. Weights were increased at each visit.

RESULTS

Patients' one-repetition maximum increased (right leg 13 to 21 lb, P = 0.00; left leg 15 to 22 lb, P = 0.00). Patients also improved in habitual (18 to 12 s, P = 0.01) and tandem (38 to 26 s, P = 0.00) 20-foot walking times and sit-to-stand time (5 to 3 s, P = 0.01).

CONCLUSION

The primary care physician can initiate a home-based leg-strengthening program that is practical for and well tolerated by the frail elderly.