Effects of exercise training on left ventricular function and peripheral resistance in patients with chronic heart failure: A randomized trial

Effect of exercise training on ventilatory efficiency in patients with heart disease: a review

The analysis of ventilatory efficiency in cardiopulmonary exercise testing has proven useful for assessing the presence and severity of cardiorespiratory diseases. During exercise, efficient pulmonary gas exchange is characterized by uniform matching of lung ventilation with perfusion. By contrast, mismatching is marked by inefficient pulmonary gas exchange, requiring increased ventilation for a given CO2 production. The etiology of increased and inefficient ventilatory response to exercise in heart disease is multifactorial, involving both peripheral and central mechanisms. Exercise training has been recommended as non-pharmacological treatment for patients with different chronic cardiopulmonary diseases. In this respect, previous studies have reported improvements in ventilatory efficiency after aerobic exercise training in patients with heart disease. Against this background, the primary objective of the present review was to discuss the pathophysiological mechanisms involved in abnormal ventilatory response to exercise, with an emphasis on both patients with heart failure syndrome and coronary artery disease. Secondly, special focus was dedicated to the role of aerobic exercise training in improving indices of ventilatory efficiency among these patients, as well as to the underlying mechanisms involved.

Preventing heart failure: the role of physical activity

PURPOSE OF REVIEW

Heart failure prevention is an important public health goal. Increased physical activity and exercise may help to prevent heart failure, as they are associated with reduced heart failure incidence and potentially act through a variety of mechanisms to slow disease progression.

RECENT FINDINGS

Increased physical activity, higher cardiorespiratory fitness, and lower sedentary time are associated with reduced heart failure incidence. These associations are consistent for occurrence of heart failure with both preserved and reduced ejection fraction, the common subphenotypes of the condition. Physiologic cardiac and vascular remodeling occurs across the normal range of physical activity in the community, and regular exercise (four to five sessions per week) is necessary to mitigate age-associated reductions in ventricular compliance and cardiac mass.

SUMMARY

Greater physical activity, less sedentary time, and improved cardiorespiratory fitness are associated with reductions in heart failure risk. Various mechanisms may explain these findings, including: reducing the prevalence of standard and novel cardiovascular risk factors, inhibiting pathologic cardiovascular remodeling, promoting physiologic remodeling, and improving cardiac, neurohormonal, skeletal muscle, pulmonary, renal, and vascular performance. Future research is needed to elucidate the optimal timing, duration, and modality of physical activity and exercise training necessary to prevent the development of heart failure.

Exercise-based cardiac rehabilitation for adults after heart valve surgery

BACKGROUND

Exercise-based cardiac rehabilitation may benefit heart valve surgery patients. We conducted a systematic review to assess the evidence for the use of exercise-based intervention programmes following heart valve surgery.

OBJECTIVES

To assess the benefits and harms of exercise-based cardiac rehabilitation compared with no exercise training intervention, or treatment as usual, in adults following heart valve surgery. We considered programmes including exercise training with or without another intervention (such as a psycho-educational component).

SEARCH METHODS

We searched: the Cochrane Central Register of Controlled Trials (CENTRAL); the Database of Abstracts of Reviews of Effects (DARE); MEDLINE (Ovid); EMBASE (Ovid); CINAHL (EBSCO); PsycINFO (Ovid); LILACS (Bireme); and Conference Proceedings Citation Index-S (CPCI-S) on Web of Science (Thomson Reuters) on 23 March 2015. We handsearched Web of Science, bibliographies of systematic reviews and trial registers (ClinicalTrials.gov, Controlled-trials.com, and The World Health Organization International Clinical Trials Registry Platform).

SELECTION CRITERIA

We included randomised clinical trials that investigated exercise-based interventions compared with no exercise intervention control. The trial participants comprised adults aged 18 years or older who had undergone heart valve surgery for heart valve disease (from any cause) and received either heart valve replacement, or heart valve repair.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data. We assessed the risk of systematic errors ('bias') by evaluation of bias risk domains. Clinical and statistical heterogeneity were assessed. Meta-analyses were undertaken using both fixed-effect and random-effects models. We used the GRADE approach to assess the quality of evidence. We sought to assess the risk of random errors with trial sequential analysis.

MAIN RESULTS

We included two trials from 1987 and 2004 with a total 148 participants who have had heart valve surgery. Both trials had a high risk of bias.There was insufficient evidence at 3 to 6 months follow-up to judge the effect of exercise-based cardiac rehabilitation compared to no exercise on mortality (RR 4.46 (95% confidence interval (CI) 0.22 to 90.78); participants = 104; studies = 1; quality of evidence: very low) and on serious adverse events (RR 1.15 (95% CI 0.37 to 3.62); participants = 148; studies = 2; quality of evidence: very low). Included trials did not report on health-related quality of life (HRQoL), and the secondary outcomes of New York Heart Association class, left ventricular ejection fraction and cost. We did find that, compared with control (no exercise), exercise-based rehabilitation may increase exercise capacity (SMD -0.47, 95% CI -0.81 to -0.13; participants = 140; studies = 2, quality of evidence: moderate). There was insufficient evidence at 12 months follow-up for the return to work outcome (RR 0.55 (95% CI 0.19 to 1.56); participants = 44; studies = 1; quality of evidence: low). Due to limited information, trial sequential analysis could not be performed as planned.

AUTHORS' CONCLUSIONS

Our findings suggest that exercise-based rehabilitation for adults after heart valve surgery, compared with no exercise, may improve exercise capacity. Due to a lack of evidence, we cannot evaluate the impact on other outcomes. Further high-quality randomised clinical trials are needed in order to assess the impact of exercise-based rehabilitation on patient-relevant outcomes, including mortality and quality of life.

Exercise and sports in cardiac patients and athletes at risk: Balance between benefit and harm

Physical training has a well-established role in the primary and secondary prevention of coronary artery disease. Moderate exercise has been shown to be beneficial in chronic stable heart failure. Competitive sports, however, is contraindicated in most forms of hypertrophic cardiomyopathy (HCM), in myocarditis, in pericarditis, and in right ventricular cardiomyopathy/dysplasia. In most European countries, the recommendations of medical societies or public bodies state that these diseases have to be ruled out by prescreening before an individual can take up competitive sports. But the intensity and quality of this health check vary considerably from country to country, from the type of sports activity, and from the individuals who want to participate in sports. Prescreening on an individual basis should also be considered for leisure sports, particularly in people who decide to start training in middle age after years of physical inactivity to regain physical fitness. In leisure sports the initiative for a medical check-up lies primarily in the hands of the "healthy" individual. If she or he plans to participate in extreme forms of endurance sports with excessive training periods such as a marathon or ultramarathon and competitive cycling or rowing, they should be aware that high-intensity endurance sports can lead to structural alterations of the heart muscle even in healthy individuals. Physical exercise in patients with heart disease should be accompanied by regular medical check-ups. Most rehabilitation programs in Europe perform physical activity and training schedules according to current guidelines. Little is known about athletes who are physically handicapped and participate in competitive sports or the Paralympics, and even less is known about individuals with intellectual disabilities (ID) who participate in local, regional, international competitions or the Special Olympics or just in leisure sport activities.

Increases in core temperature counterbalance effects of haemoconcentration on blood viscosity during prolonged exercise in the heat

NEW FINDINGS

What is the central question of this study? The purpose of the present study was to determine the effects of exercise-induced haemoconcentration and hyperthermia on blood viscosity. What is the main finding and its importance? Exercise-induced haemoconcentration, increased plasma viscosity and increased blood aggregation, all of which increased blood viscosity, were counterbalanced by increased red blood cell (RBC) deformability (e.g. RBC membrane shear elastic modulus and elongation index) caused by the hyperthermia. Thus, blood viscosity remained unchanged following prolonged moderate-intensity exercise in the heat. Previous studies have reported that blood viscosity is significantly increased following exercise. However, these studies measured both pre- and postexercise blood viscosity at 37 °C even though core and blood temperatures would be expected to have increased during the exercise. Consequently, the effect of exercise-induced hyperthermia on mitigating change in blood viscosity may have been missed. The purpose of this study was to isolate the effects of exercise-induced haemoconcentration and hyperthermia and to determine their combined effects on blood viscosity. Nine subjects performed 2 h of moderate-intensity exercise in the heat (37 °C, 40% relative humidity), which resulted in significant increases from pre-exercise values for rectal temperature (from 37.11 ± 0.35 to 38.76 ± 0.13 °C), haemoconcentration (haematocrit increased from 43.6 ± 3.6 to 45.6 ± 3.5%) and dehydration (change in body weight = -3.6 ± 0.7%). Exercise-induced haemoconcentration significantly (P < 0.05) increased blood viscosity by 9% (from 3.97 to 4.33 cP at 300 s(-1)), whereas exercise-induced hyperthermia significantly decreased blood viscosity by 7% (from 3.97 to 3.69 cP at 300 s(-1)). When both factors were considered together, there was no overall change in blood viscosity (from 3.97 to 4.03 cP at 300 s(-1)). The effects of exercise-induced haemoconcentration, increased plasma viscosity and increased red blood cell aggregation, all of which increased blood viscosity, were counterbalanced by increased red blood cell deformability (e.g. red blood cell membrane shear elastic modulus and elongation index) caused by the hyperthermia. Thus, blood viscosity remained unchanged following prolonged moderate-intensity exercise in the heat.

Impact of Exercise Training on Peak Oxygen Uptake and its Determinants in Heart Failure with Preserved Ejection Fraction

Heart failure with preserved ejection (HFpEF) accounts for over 50 % of all HF cases, and the proportion is higher among women and older individuals. A hallmark feature of HFpEF is dyspnoea on exertion and reduced peak aerobic power (VO_2peak) secondary to central and peripheral abnormalities that result in reduced oxygen delivery to and/or utilisation by exercising skeletal muscle. The purpose of this brief review is to discuss the role of exercise training to improve VO_2peak and the central and peripheral adaptations that reduce symptoms following physical conditioning in patients with HFpEF.

Cardiac Rehabilitation in Patients With Heart Failure: New Perspectives in Exercise Training

Exercise training is recommended to patients with chronic heart failure (CHF) and reduced ejection fraction at a class 1 evidence level. Currently the 'dose' of exercise (dose being both volume and intensity) still remains uncertain and the best form of aerobic exercise training has not been defined. Guidelines commonly use heart rate (HR) as a target factor for both moderate continuous and interval training exercises. However, exercise training guided by HR can be limited in CHF patients due to chronotropic incompetence and beta-blocker treatment. In our study, we systematically addressed the above issues by applying a training method that takes into account both the volume and intensity of exercise on an individual basis. This method is referred to as individual TRaining IMPulses (TRIMPi). In this review, we summarise a series of investigations that used TRIMPi and different exercise forms to quantify the optimum training load in CHF patients. This review also highlights the way TRIMPi and the individual exercise dose affects cardiorespiratory, metabolic and autonomic cardiac adaptations.

[Exercise training as a key component of heart failure therapy]

Physical exercise has been recognized as a standard therapy in the guidelines for secondary prevention of chronic heart failure. In clinical practice its benefits are widely underestimated. It is still too rarely applied as a therapeutic component, despite overwhelming scientific evidence, including meta-analyses illustrating the positive effect on exercise capacity, quality of life and hospitalization. It is crucial that patients undergo a thorough clinical investigation, including exercise testing and are in a clinically stable condition for at least 6 weeks under optimal guideline-conform medicinal therapy before exercise training is initiated. Moreover, it is important that only approved exercise regimens should be prescribed and exercise sessions should be appropriately monitored. Both moderate continuous endurance training and recently developed interval training have been shown to be safe and effective in chronic heart failure. Ideally, endurance training should be combined with moderate resistance training. Current evidence clearly demonstrates a dose-response relationship in the way that beneficial effects of exercise training are strongly related to factors such as exercise duration and intensity. Development of strategies that support long-term adherence to exercise training are a crucial challenge for both daily practice and future research.

Associations between vasodilatory capacity, physical activity and sleep among younger and older adults

INTRODUCTION

Exercise promotes cardiovascular health through its direct impact on the vascular endothelium. Conversely, poor sleep quality is associated with endothelial dysfunction, which may explain the increased cardiovascular disease amongst poor sleepers. Yet, the influence of physical activity and poor sleep quality on vascular health is not clear.

PURPOSE

This study examined the relationships between forearm vasodilatory capacity, self-reported sleep quality and free-living, actigraphy-derived energy expenditure in a group of young and older community dwelling adults.

METHODS

Venous occlusion plethysmography determined baseline and peak forearm blood flow following reactive hyperemia. Sleep quality was measured using the Pittsburgh Sleep Quality Index (PSQI). Measures of body composition were assessed using dual energy X-ray absorptiometry.

RESULTS

A total of 104 (61 young; 43 old) participants completed the study. In general, younger participants were more active, as determined by steps per day and average daily energy expenditure, but reported poorer sleep quality. In the combined sample, those who reported moderate sleep disturbances (PSQI total score; 11-15) had significantly lower vasodilatory capacity (16.8 ± 7.6 ml/100 ml/min) compared to those who reported no sleep disturbance (PSQI total score; 0-5) (22.3 ± 7.2 ml/100 ml/min) or mild sleep disturbance (PSQI total score; 6-10) (22.3 ± 8.1 ml/100 ml/min) (p < 0.01). After adjustment for physical activity, total body fat and age, moderately poor sleep remained an independent predictor of forearm vasodilatory capacity.

CONCLUSIONS

These findings suggest that any positive vascular benefits accrued through increased physical activity might be offset by the negative consequences of chronically disturbed sleep.

Exercise training normalizes renal blood flow responses to acute hypoxia in experimental heart failure: role of the α1-adrenergic receptor

Recent data suggest that exercise training (ExT) is beneficial in chronic heart failure (CHF) because it improves autonomic and peripheral vascular function. In this study, we hypothesized that ExT in the CHF state ameliorates the renal vasoconstrictor responses to hypoxia and that this beneficial effect is mediated by changes in α1-adrenergic receptor activation. CHF was induced in rabbits. Renal blood flow (RBF) and renal vascular conductance (RVC) responses to 6 min of 5% isocapnic hypoxia were assessed in the conscious state in sedentary (SED) and ExT rabbits with CHF with and without α1-adrenergic blockade. α1-adrenergic receptor expression in the kidney cortex was also evaluated. A significant decline in baseline RBF and RVC and an exaggerated renal vasoconstriction during acute hypoxia occurred in CHF-SED rabbits compared with the prepaced state (P < 0.05). ExT diminished the decline in baseline RBF and RVC and restored changes during hypoxia to those of the prepaced state. α1-adrenergic blockade partially prevented the decline in RBF and RVC in CHF-SED rabbits and eliminated the differences in hypoxia responses between SED and ExT animals. Unilateral renal denervation (DnX) blocked the hypoxia-induced renal vasoconstriction in CHF-SED rabbits. α1-adrenergic protein in the renal cortex of animals with CHF was increased in SED animals and normalized after ExT. These data provide evidence that the acute decline in RBF during hypoxia is caused entirely by the renal nerves but is only partially mediated by α1-adrenergic receptors. Nonetheless, α1-adrenergic receptors play an important role in the beneficial effects of ExT in the kidney.

Possible neurocognitive benefits of exercise in persons with heart failure

More than 6 million Americans have heart failure (HF) and more than 500,000 are diagnosed each year. In addition to its many adverse medical consequences, HF is also a significant risk factor for neurological disorders like Alzheimer's disease and associated with cognitive impairment long prior to the onset of these conditions. Converging bodies of literature suggest cognitive dysfunction in HF may be at least partially modifiable. One key mechanism for cognitive improvement is improved cerebral blood flow, which may be possible with exercise in patients with HF. This brief review provides a model for the likely neurocognitive benefits of exercise in HF and encourages further work in this area.

Effects of Cardiopulmonary Exercise Rehabilitation on Left Ventricular Mechanical Efficiency and Ventricular-Arterial Coupling in Patients With Systolic Heart Failure

BACKGROUND

Success of cardiac rehabilitation (CR) is generally assessed by the objective improvement in peak volume of inhaled oxygen (VO2) measured by cardiopulmonary exercise test (CPX). However, cardiac mechanical efficiency and ventricular-arterial coupling (VAC) are the other important dimensions of the heart failure pathophysiology, which are not included in CPX-derived data. The effect of cardiac rehabilitation on left ventricular (LV) efficiency or VAC in unselected heart failure patients has not been studied thus far.

METHODS AND RESULTS

Thirty patients with an ejection fraction of ≤45% were recruited for 20 sessions of exercise-based CR. Noninvasive LV pressure-volume loops were constructed and VAC was calculated with the help of applanation tonometry and echocardiography before and after CR. VAC showed an improved mechanical efficiency profile and increased significantly from 0.56±0.18 to 0.67±0.21 (P=0.02). LV mechanical efficiency improved from 43.9±9.1% to 48.8±9.1% (P=0.01). The change in peak VO2 was not in a significant correlation with the change in VAC (r=-0.18; P=0.31), mechanical efficiency (r=-0.16, P=0.39), or the change in ejection fraction (r=-0.07; P=0.68).

CONCLUSIONS

CR is associated with an improvement in VAC and LV mechanical efficiency in heart failure patients. Further studies are needed to determine the incremental value of VAC and mechanical efficiency over CPX-derived data in predicting clinical outcomes.

Enhanced external counterpulsation improves endothelial function and exercise capacity in patients with ischaemic left ventricular dysfunction

Enhanced external counterpulsation (EECP) therapy decreases angina episodes and improves quality of life in patients with left ventricular (LV) dysfunction (LVD). However, studies have not elucidated the mechanisms of action and overall effects of EECP in patients with LVD. The purpose of the present study was to investigate the effects of EECP on endothelial function in peripheral conduit arteries and exercise capacity (peak Vo2 ) in patients with LVD. Patients with ischaemic LVD (ejection fraction (EF) 34.5 ± 4.2%; n = 9) and patients with symptomatic coronary artery disease (CAD) and preserved LV function (EF 53.5 ± 6.6%; n = 15) were studied before and after 35 sessions (1 h) of EECP. Brachial and femoral artery flow-mediated dilation (bFMD and fFMD, respectively) were evaluated using high-resolution ultrasound. Enhanced external counterpulsation elicited similar significant improvements in the following FMD parameters in the CAD and LVD groups (P ≥ 0.05 between groups for all): absolute bFMD (+53% and +70%, respectively), relative bFMD (+50% and +74%, respectively), bFMD normalized for shear rate (+70% and +61%, respectively), absolute fFMD (+33% and +21%, respectively) and relative fFMD (+32% and +17%, respectively). In addition, EECP significantly improved plasma levels of nitrate/nitrite (+55% and +28%) and prostacyclin (+50% and +70%), as well as peak Vo2 (+36% and +21%), similarly in both the CAD and LVD groups (P ≥ 0.05 between groups for all). Despite reduced LV function, EECP therapy significantly improves peripheral vascular function and functional capacity in CAD patients with ischaemic LVD to a similar degree to that seen in CAD patients with preserved LV function.

Exercise training in chronic heart failure: improving skeletal muscle O2 transport and utilization

Chronic heart failure (CHF) impairs critical structural and functional components of the O2 transport pathway resulting in exercise intolerance and, consequently, reduced quality of life. In contrast, exercise training is capable of combating many of the CHF-induced impairments and enhancing the matching between skeletal muscle O2 delivery and utilization (Q̇mO2 and V̇mO2 , respectively). The Q̇mO2 /V̇mO2 ratio determines the microvascular O2 partial pressure (PmvO2 ), which represents the ultimate force driving blood-myocyte O2 flux (see Fig. 1). Improvements in perfusive and diffusive O2 conductances are essential to support faster rates of oxidative phosphorylation (reflected as faster V̇mO2 kinetics during transitions in metabolic demand) and reduce the reliance on anaerobic glycolysis and utilization of finite energy sources (thus lowering the magnitude of the O2 deficit) in trained CHF muscle. These adaptations contribute to attenuated muscle metabolic perturbations (e.g., changes in [PCr], [Cr], [ADP], and pH) and improved physical capacity (i.e., elevated critical power and maximal V̇mO2 ). Preservation of such plasticity in response to exercise training is crucial considering the dominant role of skeletal muscle dysfunction in the pathophysiology and increased morbidity/mortality of the CHF patient. This brief review focuses on the mechanistic bases for improved Q̇mO2 /V̇mO2 matching (and enhanced PmvO2 ) with exercise training in CHF with both preserved and reduced ejection fraction (HFpEF and HFrEF, respectively). Specifically, O2 convection within the skeletal muscle microcirculation, O2 diffusion from the red blood cell to the mitochondria, and muscle metabolic control are particularly susceptive to exercise training adaptations in CHF. Alternatives to traditional whole body endurance exercise training programs such as small muscle mass and inspiratory muscle training, pharmacological treatment (e.g., sildenafil and pentoxifylline), and dietary nitrate supplementation are also presented in light of their therapeutic potential. Adaptations within the skeletal muscle O2 transport and utilization system underlie improvements in physical capacity and quality of life in CHF and thus take center stage in the therapeutic management of these patients.

Modulation of cardiovascular toxicity in Hodgkin lymphoma: potential role and mechanisms of aerobic training

Hodgkin lymphoma (HL) outcomes have improved due to advances in cancer treatment. However, HL survivors remain at increased risk for cardiovascular (CV) morbidity and mortality related to the long-term cardiotoxicity of HL treatment, particularly anthracycline chemotherapy and mediastinal radiotherapy. The role of aerobic training for the prevention of CV disease in the general population has been well established. However the safety and efficacy of aerobic training on CV outcomes has not been well studied in HL survivors. The purpose of this paper is to provide an up-to-date summary of the treatment-related adverse CV effects in HL survivors, review the CV benefits of exercise and review the limited evidence on the potential CV benefit of aerobic training in HL survivors.

The effect of upper-extremity aerobic exercise on complex regional pain syndrome type I: a randomized controlled study on subacute stroke

BACKGROUND AND PURPOSE

Complex regional pain syndrome type I (CPRS I), is a complex of symptoms characterized by diffuse pain usually with associated swelling, vasomotor instability, and severe functional impairment of the affected extremity in stroke patients. Pain is a prominent feature and is often refractory to variety of treatment.

METHODS

To investigate the clinical, functional, and psychosocial effects of upper extremity aerobic exercise (UEAE) and compare the effect of aerobic exercise with that of conventional physiotherapy in patients with CPRS type I following stroke as a randomized controlled assesor blinded 4  week-study. A total of 52 inpatients with stroke [mean age: 65.95 ± 8.7 (min. = 53, max. = 80) years, and the mean age of the control group was 67.50 ± 11.2 years], all within 6  months post-stroke and diagnosed with CPRS I. The UEAE program consisted of an arm crank ergometer (10  W/min), in addition to a conventional physiotherapy (whirlpool, TENS, retrograd massage). Primary outcome measures were CPRS clinical determinants (pain, hyperalgesia, allodynia, and autonomic abnormalities) secondary outcome measures were functional independence measure (FIM), Nottingham Health Profile (NHP), and Beck Depression Scale scores that were performed at 0  month (baseline) and 4  weeks (post-treatment).

RESULTS

In UEAE group, patients reported significant pain relief (89.9%) and significant decline in CRPS signs and symptoms. The mean change in pain at shoulder, pain at the hand as well as and NHP and BDS scores between groups were statistically significant (P < 0.05).

CONCLUSIONS

UEAE made an excellent improvement in the symptoms and signs of CRPS I. Combined treatment of conventional physiotherapy and aerobic exercises may be an excellent synthesis for this syndrome in these patients.

Impact of weight reduction on pericardial adipose tissue and cardiac structure in patients with atrial fibrillation

BACKGROUND

Obesity and pericardial adipose tissue are independent risk factors for atrial fibrillation (AF) and adverse cardiac structural remodeling. The effect of weight reduction on pericardial adipose tissue and cardiac structure remains unknown.

METHODS

We prospectively performed cardiac magnetic resonance imaging on 87 participants with AF undergoing either structured weight management (intervention) or general lifestyle advice (control). We measured pericardial adipose tissue, atrial and ventricular volumes, and myocardial mass at baseline and 12 months.

RESULTS

In total, 69 participants underwent baseline and 12-month follow-up cardiac magnetic resonance imaging (intervention n = 36 and controls n = 33). From baseline to 12 months, weight loss (kg, mean [95% CI]) was greater in the intervention group from 101.5 kg (97.2-105.8 kg) to 86.5 kg (81.2-91.9 kg) as compared with controls from 102.6 kg (97.2-108.1 kg) to 98.7 kg (91.0-106.3 kg) (time-group interaction P < .001). The intervention group showed a reduction in left atrial volumes (mL) from 105.0 mL (98.9-111.1 mL) to 96.4 mL (91.6-101.1 mL), whereas the change in the control group was from 108.8 mL (99.6-117.9 mL) to 108.9 mL (99.8-118.0 mL) (time-group interaction P < .001). There was a decline in pericardial adipose tissue (cm(3)) from 140.9 cm(3) (129.3-152.4 cm(3)) to 118.8 cm(3) (108.1-129.6 cm(3)) and myocardial mass (g) from 137.6 g (128.1-147.2 g) to 123.1 g (114.5-131.7 g) in the intervention group, whereas the change in the control group was from 143.2 cm(3) (124.6-161.7 cm(3)) to 147.2 cm(3) (128.9-165.4 cm(3)) for pericardial adipose tissue and 138.3 g (124.8-151.8 g) to 140.7 g (127.4-154.1 g) for myocardial mass (both variables, time-group interaction P < .001).

CONCLUSIONS

Weight reduction results in favorable structural remodeling and a reduction in pericardial adipose tissue burden.

Effect of exercise training on the quality of life and echocardiography parameter of systolic function in patients with chronic heart failure: a randomized trial

Background:

Ejection fraction promotion in heart failure patients reduces mortalities and limitations.

Objectives:

This study was to investigate the effect of exercise on ejection fraction of chronic heart failure patients.

Patients and Methods:

The present study was conducted on patients with chronic heart failure. 66 patients were divided randomly into two experimental and control groups of 33 each. The subjects were male and female. The patients in experimental group followed an exercise program three sessions per week for 24 weeks. Echocardiography and quality of life questionnaire were used to gather data. The data were analyzed by SPSS 18 through pair and independent t-test.

Results:

The results indicated a significant difference in left ventricular diameter (LV-ESD, LV-EDD) and ejection fraction at the end of exercise program in experimental group and 24 weeks after in control group. There was a significant difference in quality of life in physical performance, activity limitation following physical problems, energy and fatigue, social performance, physical pain, and public health (P < 0.05 for all) between two groups.

Conclusions:

Exercise program increases ejection fraction and quality of life in chronic heart failure patients, associated with management of disease by health team.

The effect of cinnamon extract and long-term aerobic training on heart function, biochemical alterations and lipid profile following exhaustive exercise in male rats

PURPOSE

Regular training is suggested to offer a host of benefits especially on cardiovascular system. In addition, medicinal plants can attenuate oxidative stress-mediated damages induced by stressor insults. In this study, we investigated the concomitant effect of cinnamon extract and long-term aerobic training on cardiac function, biochemical alterations and lipid profile following exhaustive exercise.

METHODS

Male Wistar rats (250-300 g) were divided into five groups depending on receiving regular training, cinnamon bark extraction, none or both of them, and then encountered with an exhausted exercise in last session. An 8-week endurance training program was designed with a progressive increase in training speed and time. Myocardial hemodynamics was monitored using a balloon-tipped catheter inserted into left ventricles. Blood samples were collected for analyzing biochemical markers, lipid profiles and lipid-peroxidation marker, malondealdehyde (MDA).

RESULTS

Trained animals showed an enhanced cardiac force and contractility similar to cinnamon-treated rats. Co-application of regular training and cinnamon had additive effect in cardiac hemodynamic (P<0.05). Both regular training and supplementation with cinnamon significantly decreased serum levels of total cholesterol, low-density lipoprotein (LDL), and increased high-density lipoprotein (HDL) level and HDL/LDL ratio as compared to control group (P<0.01). Furthermore, pre-treatment with cinnamon extract and/or regular training significantly reduced MDA level elevation induced by exhausted exercise (P<0.01).

CONCLUSION

Long-term treatment of rats with cinnamon and regular training improved cardiac hemodynamic through an additive effect. The positive effects of cinnamon and regular training on cardiac function were associated with a reduced serum MDA level and an improved blood lipid profile.

Clinical utility of exercise training in heart failure with reduced and preserved ejection fraction

Reduced exercise tolerance is an independent predictor of hospital readmission and mortality in patients with heart failure (HF). Exercise training for HF patients is well established as an adjunct therapy, and there is sufficient evidence to support the favorable role of exercise training programs for HF patients over and above the optimal medical therapy. Some of the documented benefits include improved functional capacity, quality of life (QoL), fatigue, and dyspnea. Major trials to assess exercise training in HF have, however, focused on heart failure with reduced ejection fraction (HFREF). At least half of the patients presenting with HF have heart failure with preserved ejection fraction (HFPEF) and experience similar symptoms of exercise intolerance, dyspnea, and early fatigue, and similar mortality risk and rehospitalization rates. The role of exercise training in the management of HFPEF remains less clear. This article provides a brief overview of pathophysiology of reduced exercise tolerance in HFREF and heart failure with preserved ejection fraction (HFPEF), and summarizes the evidence and mechanisms by which exercise training can improve symptoms and HF. Clinical and practical aspects of exercise training prescription are also discussed.

Benefits of cardiac rehabilitation in heart failure patients according to etiology: INCARD French study

We investigated the impact of heart failure (HF) etiology on the outcome of cardiac rehabilitation (CR) assessed by functional and clinical parameters. Treatment of chronic HF requires multidisciplinary approaches with a recognized role for CR. INCARD is a French study aimed at evaluating the benefits of sustainable CR in coronary (C) and noncoronary patients (NC) treated and educated during a 24-month period of follow-up. Prospective, monocentric patients with HF underwent inpatient physical training followed by a home-based program. Evaluations were performed at inclusion, discharge, 3 months after discharge, and subsequently every 6 months over the 24 months of outpatient rehabilitation.A total of 147 HF patients with left ventricular ejection fraction (LVEF) <40 were admitted to the CR center, 63 accepted to join INCARD (29 C and 34 NC). Although the C participants C having both an echocardiographic LVEF and an initially lower peak VO2, inpatient rehabilitation improved all functional parameters. Only NC showed an improved LVEF during the first 3 months of outpatient-follow-up. The main outcome of the outpatient rehabilitation was a trend toward stabilization of clinical and laboratory parameters with no significant difference between C and NC. This study confirms the benefits of initial HF inpatient rehabilitation and encourages prolonged outpatient monitoring. The results on functional parameters suggest exercise training should be conducted regardless of the HF etiology.

Exercise-based rehabilitation for heart failure: systematic review and meta-analysis

OBJECTIVE

To update the Cochrane systematic review of exercise-based cardiac rehabilitation (CR) for heart failure.

METHODS

A systematic review and meta-analysis of randomised controlled trials was undertaken. MEDLINE, EMBASE and the Cochrane Library were searched up to January 2013. Trials with 6 or more months of follow-up were included if they assessed the effects of exercise interventions alone or as a component of comprehensive CR programme compared with no exercise control.

RESULTS

33 trials were included with 4740 participants predominantly with a reduced ejection fraction (<40%) and New York Heart Association class II and III. Compared with controls, while there was no difference in pooled all-cause mortality between exercise CR with follow-up to 1 year (risk ratio (RR) 0.93; 95% CI 0.69 to 1.27, p=0.67), there was a trend towards a reduction in trials with follow-up beyond 1 year (RR 0.88; 0.75 to 1.02, 0.09). Exercise CR reduced the risk of overall (RR 0.75; 0.62 to 0.92, 0.005) and heart failure-specific hospitalisation (RR 0.61; 0.46 to 0.80, 0.0004) and resulted in a clinically important improvement in the Minnesota Living with Heart Failure questionnaire (mean difference: -5.8 points, -9.2 to -2.4, 0.0007). Univariate meta-regression analysis showed that these benefits were independent of the type and dose of exercise CR, and trial duration of follow- up, quality or publication date.

CONCLUSIONS

This updated Cochrane review shows that improvements in hospitalisation and health-related quality of life with exercise-based CR appear to be consistent across patients regardless of CR programme characteristics and may reduce mortality in the longer term. An individual participant data meta-analysis is needed to provide confirmatory evidence of the importance of patient subgroup and programme level characteristics (eg, exercise dose) on outcome.

Cardiovascular effects of high-intensity interval aerobic training combined with strength exercise in patients with chronic heart failure. A randomized phase III clinical trial

BACKGROUND

The aim of this work was to evaluate the effect of high-intensity interval exercise (i.e., 30s at 100% of max workload, followed by 30s at rest, 45 min 3 days/week working-out schedule for 12 weeks) on left ventricular function and aortic elastic properties among chronic heart failure (CHF) patients.

METHODS

This study is a phase III clinical trial. Of the 100 consecutive CHF patients (NYHA classes II-IV, ejection fraction<50%) that were randomly allocated, 72 completed the study (exercise training group, n=33, 63 ± 9 years, 88% men, and control group, n=39, 56 ± 11 years, 82% men). All patients underwent cardiopulmonary stress test, non-invasive high-fidelity tonometry of the radial artery, pulse wave velocity measurement using a SphygmoCor device and echocardiography before and after the completion of the training program.

RESULTS

Both groups reported similar medical characteristics and physical activity status. General mixed effects models revealed that the intervention group reduced pulse wave velocity by 9% (p=0.05); Emv/Vp by 14% (p=0.06); E to A ratio by 24% (p=0.004), E to Emv ratio by 8% (p=0.05), MLHFQ score by 66% (p=0.003) and the depression score by 19% (p=0.5); increased augmentation index by 29%; VTI by 4% (p=0.05), 6-minute-walk distance up to 13% (p=0.05), peak oxygen uptake by 28% (p=0.001) and peak power by 25% (p=0.005). There were no significant changes in the control group.

CONCLUSION

Interval high-intensity aerobic training, combined with strength exercise, seems to benefit aortic dilatation capacity and augmented systolic pressure in parallel with improvement in left ventricular diastolic function and quality of life.

Cardiac rehabilitation for people with heart disease: an overview of Cochrane systematic reviews

BACKGROUND

Overviews are a new approach to summarising evidence and synthesising results from related systematic reviews.

OBJECTIVES

To conduct an overview of Cochrane systematic reviews to provide a contemporary review of the evidence for delivery of cardiac rehabilitation, to identify opportunities for merging or splitting existing Cochrane reviews, and to identify current evidence gaps to inform new cardiac rehabilitation systematic review titles.

METHODS

We searched The Cochrane Database of Systematic Reviews (2014, Issue 10) to identify systematic reviews that addressed the objectives of this overview. We assessed the quality of included reviews using the Revised Assessment of Multiple Systematic Reviews (R-AMSTAR) measurement tool and the quality of the evidence for reported outcomes using the GRADE framework. The focus of the data presentation was descriptive with detailed tabular presentations of review level and trial level characteristics and results.

MAIN RESULTS

We found six Cochrane systematic reviews and judged them to be of high methodological quality. They included 148 randomised controlled trials (RCTs) in 98,093 participants. Compared with usual care alone, the addition of exercise-based cardiac rehabilitation in low-risk people after myocardial infarction or percutaneous coronary intervention or with heart failure appeared to have no impact on mortality, but did reduce hospital admissions and improved health-related quality of life. Psychological- and education-based interventions alone appeared to have little or no impact on mortality or morbidity but may have improved health-related quality of life. Home- and centre-based programmes were equally effective in improving quality of life outcomes at similar healthcare costs. Selected interventions can increase the uptake of cardiac rehabilitation programmes whilst there is currently only weak evidence to support interventions that improve adherence to cardiac rehabilitation programmes. The quality of the primary RCTs in the included systematic reviews was variable, and limitations in the methodological quality of the RCTs led to downgrading of the quality of the evidence, which varied widely by review and by outcome.

AUTHORS' CONCLUSIONS

Exercise-based cardiac rehabilitation is an effective and safe therapy to be used in the management of clinically stable people following myocardial infarction or percutaneous coronary intervention or who have heart failure. Future RCTs of cardiac rehabilitation need to improve their reporting methods and reflect the real world practice better including the recruitment of higher risk people and consideration of contemporary models of cardiac rehabilitation delivery, and identify effective interventions for enhancing adherence to rehabilitation.

Study of adherence to exercise in heart failure: the HEART camp trial protocol

BACKGROUND

Adherence to the Heart Failure Society of America (HFSA) 2010 guidelines recommending 30 minutes of supervised moderate intensity exercise five days per week is difficult for patients with heart failure (HF). Innovative programs are needed to assist HF patients to adhere to long-term exercise. The objective of this prospective randomized two-group repeated measures experimental design is to determine the efficacy of a behavioral exercise training intervention on long-term adherence to exercise at 18 months in patients with heart failure.

METHODS/DESIGN

A sample size of 246 subjects with heart failure will be recruited over a 3 year period. All subjects receive a cardiopulmonary exercise test and 9 supervised exercise training sessions during a 3 week run-in period prior to randomization. Subjects completing at least 6 of 9 training sessions are randomized to the HEART Camp Intervention group (HC) or to a standard care (SC) exercise group. The HC intervention group receives cognitive-behavioral strategies that address the intervention components of knowledge, attitudes, self-efficacy, behavioral self-management skills and social support. The SC group is provided access to the exercise facility and regular facility staff for the 18 month study period. The primary aim is to evaluate the effect of HEART Camp on adherence to exercise, with our central hypothesis that the HC group will have significantly better adherence to exercise at 18 months. Secondary aims include evaluating which components of the HEART Camp intervention mediate the effects of the intervention on adherence; evaluating the effect of HEART Camp on specific health outcomes; exploring selected demographic variables (race, gender, age) as potential moderators of the effect of the HEART Camp intervention on adherence; and exploring the perceptions and experiences that contextualize exercise adherence.

DISCUSSION

The HEART Camp intervention is the first to test a multi-component intervention designed to improve long-term adherence to exercise behavior in patients with HF. Improving long-term adherence to exercise is the logical first step to ensure the required dose of exercise that is necessary to realize beneficial health outcomes and reduce costs in this burdensome chronic illness.

TRIAL REGISTRATION

Clincaltrials.gov NCT01658670.

Exercise training in patients with heart failure and preserved ejection fraction: meta-analysis of randomized control trials

BACKGROUND

Heart failure with preserved ejection fraction (HFPEF) is common and characterized by exercise intolerance and lack of proven effective therapies. Exercise training has been shown to be effective in improving cardiorespiratory fitness (CRF) in patients with systolic heart failure. In this meta-analysis, we aim to evaluate the effects of exercise training on CRF, quality of life, and diastolic function in patients with HFPEF.

METHODS AND RESULTS

Randomized controlled clinical trials that evaluated the efficacy of exercise training in patients with HFPEF were included in this meta-analysis. Primary outcome of the study was change in CRF (measured as change in peak oxygen uptake). Effect of exercise training on quality of life (estimated using Minnesota living with heart failure score), and left ventricular systolic and diastolic function was also assessed. The study included 276 patients who were enrolled in 6 randomized controlled trials. In the pooled data analysis, patients with HFPEF undergoing exercise training had significantly improved CRF (mL/kg per min; weighted mean difference, 2.72; 95% confidence interval, 1.79-3.65) and quality of life (weighted mean difference, -3.97; 95% confidence interval, -7.21 to -0.72) when compared with the control group. However, no significant change was observed in the systolic function (EF-weighted mean difference, 1.26; 95% confidence interval, -0.13% to 2.66%) or diastolic function (E/A-weighted mean difference, 0.08; 95% confidence interval, -0.01 to 0.16) with exercise training in patients with HFPEF.

CONCLUSIONS

Exercise training in patients with HFPEF is associated with an improvement in CRF and quality of life without significant changes in left ventricular systolic or diastolic function.

Exercise training in patients with heart disease: review of beneficial effects and clinical recommendations

Over the last decades exercise training has evolved into an established evidence-based therapeutic strategy with prognostic benefits in many cardiovascular diseases (CVDs): In stable coronary artery disease (CAD) exercise training attenuates disease progression by beneficially influencing CVD risk factors (i.e., hyperlipidemia, hypertension) and coronary endothelial function. In heart failure (HF) with reduced ejection fraction (HFrEF) training prevents the progressive loss of exercise capacity by antagonizing peripheral skeletal muscle wasting and by promoting left ventricular reverse remodeling with reduction in cardiomegaly and improvement of ejection fraction. Novel areas for exercise training interventions include HF with preserved ejection fraction (HFpEF), pulmonary hypertension, and valvular heart disease. In HFpEF, randomized studies indicate a lusitropic effect of training on left ventricular diastolic function associated with symptomatic improvement of exercise capacity. In pulmonary hypertension, reductions in pulmonary artery pressure were observed following endurance exercise training. Recently, innovative training methods such as high-intensity interval training, resistance training and others have been introduced. Although their prognostic value still needs to be determined, these approaches may achieve superior improvements in aerobic exercise capacity and gain in muscle mass, respectively. In this review, we give an overview of the prognostic and symptomatic benefits of exercise training in the most common cardiac disease entities. Additionally, key guideline recommendations for the initiation of training programs are summarized.

Central mechanisms for exercise training-induced reduction in sympatho-excitation in chronic heart failure

The control of sympathetic outflow in the chronic heart failure (CHF) state is markedly abnormal. Patients with heart failure present with increased plasma norepinephrine and increased sympathetic nerve activity. The mechanism for this sympatho-excitation is multiple and varied. Both depression in negative feedback sensory control mechanisms and augmentation of excitatory reflexes contribute to this sympatho-excitation. These include the arterial baroreflex, cardiac reflexes, arterial chemoreflexes and cardiac sympathetic afferent reflexes. In addition, abnormalities in central signaling in autonomic pathways have been implicated in the sympatho-excitatory process in CHF. These mechanisms include increases in central Angiotensin II and the Type 1 receptor, increased in reactive oxygen stress, upregulation in glutamate signaling and NR1 (N-methyl-D-aspartate subtype 1) receptors and others. Exercise training in the CHF state has been shown to reduce sympathetic outflow and result in increased survival and reduced cardiac events. Exercise training has been shown to reduce central Angiotensin II signaling including the Type 1 receptor and reduce oxidative stress by lowering the expression of many of the subunits of NADPH oxidase. In addition, there are profound effects on the central generation of nitric oxide and nitric oxide synthase in sympatho-regulatory areas of the brain. Recent studies have pointed to the balance between Angiotensin Converting Enzyme (ACE) and ACE2, translating into Angiotensin II and Angiotensin 1-7 as important regulators of sympathetic outflow. These enzymes appear to be normalized following exercise training in CHF. Understanding the precise molecular mechanisms by which exercise training is sympatho-inhibitory will uncover new targets for therapy.

Exercise and risk of major cardiovascular events in adult survivors of childhood hodgkin lymphoma: a report from the childhood cancer survivor study

PURPOSE

Survivors of Hodgkin lymphoma (HL) are at increased risk of treatment-related cardiovascular (CV) events; whether exercise modifies this risk is unknown.

METHODS

Survivors of HL (n = 1,187; median age, 31.2 years) completed a questionnaire evaluating vigorous-intensity exercise behavior. CV events were collected in follow-up questionnaires and graded according to Common Terminology Criteria for Adverse Events (version 4.03). The primary end point was incidence of any major (grade 3 to 5) CV event. Poisson regression analyses were used to estimate the association between exercise exposure (metabolic equivalent [MET] hours/week(-1)) and risk of major CV events after adjustment for clinical covariates and cancer treatment.

RESULTS

Median follow-up was 11.9 years (range, 1.7 to 14.3 years). Cumulative incidence of any CV event was 12.2% at 10 years for survivors reporting 0 MET hours/week(-1) compared with 5.2% for those reporting ≥ 9 MET hours/week(-1). In multivariable analyses, the incidence of any CV event decreased across increasing MET categories (Ptrend = .002). Compared with survivors reporting 0 MET hours/week(-1), the adjusted rate ratio for any CV event was 0.87 (95% CI, 0.56 to 1.34) for 3 to 6 MET hours/week(-1), 0.45 (95% CI, 0.26 to 0.80) for 9 to 12 MET hours/week(-1), and 0.47 (95% CI, 0.23 to 0.95) for 15 to 21 MET hours/week(-1). Adherence to national vigorous intensity exercise guidelines (ie, ≥ 9 MET hours/week(-1)) was associated with a 51% reduction in the risk of any CV event in comparison with not meeting the guidelines (P = .002).

CONCLUSION

Vigorous exercise was associated with a lower risk of CV events in a dose-dependent manner independent of CV risk profile and treatment in survivors of HL.

Exercise-induced changes in cardiovascular function after stroke: a randomized controlled trial

BACKGROUND AND AIMS

Cardiovascular co-morbidities are prevalent after stroke, with heart disease, hypertension and impaired glucose tolerance present in the majority of cases. Exercise has the potential to mediate cardiovascular risk factors commonly present in people with stroke. This single-blinded randomized controlled trial compared the effects of high versus low intensity exercise on fitness, cardiovascular risk factors, and cardiac function after stroke.

METHODS

Fifty participants (age 50-80 y, >1 y post-stroke) were randomized to a high-intensity Aerobic Exercise (AE) or low-intensity non-aerobic Balance/Flexibility (BF) program (6 months, 3 60-min sessions/week). Outcomes assessed by VO2 peak (primary outcome), arterial stiffness, ambulatory capacity, hemodynamics and cardiac function using echocardiography, and lipid, glucose and homocysteine levels. Assessors were blinded to group allocation.

RESULTS

Twenty-three (92%) of 25 AE group participants (withdrawals unrelated to the intervention) and all BF group participants completed the program. One BF group participant experienced 2 non-injurious falls during class. No other adverse events occurred. There were no changes in VO2 peak in either group (AE 16·9±7 to 17·4±7 ml●kg(-1) ●min(-1) vs. BF 16·9±6 to 16·6±5 ml●kg(-1) ●min(-1) , P=0·45), but AE group demonstrated greater improvement in right atrial emptying fraction (AE 30±22 to 37±22% vs. BF 35±20 to 31±20%, P=0·04). Both groups demonstrated improvements in lipid profiles, glucose and homocysteine levels, and ambulatory capacity (P<0·04).

CONCLUSIONS

This was the first study to examine the effects of aerobic exercise after stroke on cardiovascular hemodynamics. High-intensity exercise improved right-sided function and early myocardial relaxation. Low-intensity exercise may also benefit plasma lipid, glucose and inflammatory markers, and ambulatory capacity. This study is an important step towards understanding mechanisms by which exercise may reduce cardiovascular risk and function.

Physical and immunological aspects of exercise in chronic diseases

Physical inactivity and sedentary lifestyles are believed to be independent risk factors for the occurrence of numerous diseases, including, obesity, Type 2 diabetes, metabolic syndrome, cardiovascular disease, cancer and mental health, all leading to substantial morbidity and/or premature death. It has been found that regular exercise, is associated with better quality of life and health outcomes, and reduces the risk of cardiovascular disease and cancer. Here, we review the effects regular exercise has on mental health and well-being, on the immune system and in cancer, cardiovascular disease, autoimmunity and metabolic syndrome. Is exercise the new immunotherapy to treat diseases?

[Left ventricle assist device: rehabilitation and management programmes]

Progress in the medical management of patients with heart failure with systolic dysfunction has been accompanied by a significant improvement in survival and quality of life. These strategies have also resulted in changes in the clinical profile as well as an increase in the number of patients with advanced heart failure. The technological developments in left ventricular assist devices provide real hope for these patients. This article related our experience of management and the rehabilitation program realized.

Intercostal and forearm muscle deoxygenation during respiratory fatigue in patients with heart failure: potential role of a respiratory muscle metaboreflex

The purpose of this study was to determine the effect of respiratory muscle fatigue on intercostal and forearm muscle perfusion and oxygenation in patients with heart failure. Five clinically stable heart failure patients with respiratory muscle weakness (age, 66±12 years; left ventricle ejection fraction, 34±3%) and nine matched healthy controls underwent a respiratory muscle fatigue protocol, breathing against a fixed resistance at 60% of their maximal inspiratory pressure for as long as they could sustain the predetermined inspiratory pressure. Intercostal and forearm muscle blood volume and oxygenation were continuously monitored by near-infrared spectroscopy with transducers placed on the seventh left intercostal space and the left forearm. Data were compared by two-way ANOVA and Bonferroni correction. Respiratory fatigue occurred at 5.1±1.3 min in heart failure patients and at 9.3±1.4 min in controls (P<0.05), but perceived effort, changes in heart rate, and in systolic blood pressure were similar between groups (P>0.05). Respiratory fatigue in heart failure reduced intercostal and forearm muscle blood volume (P<0.05) along with decreased tissue oxygenation both in intercostal (heart failure, -2.6±1.6%; controls, +1.6±0.5%; P<0.05) and in forearm muscles (heart failure, -4.5±0.5%; controls, +0.5±0.8%; P<0.05). These results suggest that respiratory fatigue in patients with heart failure causes an oxygen demand/delivery mismatch in respiratory muscles, probably leading to a reflex reduction in peripheral limb muscle perfusion, featuring a respiratory metaboreflex.

Safety and efficacy of aerobic training in patients with cancer who have heart failure: an analysis of the HF-ACTION randomized trial

PURPOSE

To investigate the efficacy and safety of aerobic training (AT) in patients with cancer with medically stable heart failure (HF).

PATIENTS AND METHODS

A retrospective analysis of 90 patients with cancer who have HF and who were randomly assigned to AT (n = 47) or guideline-based usual care (UC; n = 43) was performed. AT consisted of three supervised sessions per week at 20 to 45 minutes per session at 60% to 70% of heart rate reserve for 12 weeks followed by home-based sessions for 4 to 12 months. The primary end point was all-cause mortality and hospitalization. Secondary end points were other clinical events, safety, and change in exercise capacity (VO(2peak)) and health-related quality of life (HRQOL).

RESULTS

Median follow-up was 35 months. In intention-to-treat (ITT) analyses, all-cause mortality or hospitalization at 2 years was 74% in the AT group compared with 67% in the UC group (adjusted hazard ratio [HR], 1.11; 95% CI, 0.69 to 1.77; P = .676). The incidence of cardiovascular mortality or cardiovascular hospitalization was significantly higher in the AT group compared with the UC group (41% v 67%; adjusted HR, 1.94; 95% CI, 1.12 to 3.16; P = .017). There were no differences in any VO(2peak) or HRQOL end points. In post hoc analyses based on adherence to AT, all-cause mortality and hospitalization was 66% in adherent patients (≥ 90 minutes per week) compared with 84% in nonadherent patients (< 90 minutes per week).

CONCLUSION

In ITT analyses, AT did not improve clinical outcomes in patients with cancer who had HF. Post hoc analyses suggested that patients not capable of adhering to the planned AT prescription may be at increased risk of clinical events.

Metabolic and structural impairment of skeletal muscle in heart failure

Physiologic endurance exercise performance is primarily limited by cardiac function. In patients with heart failure, there is dissociation between cardiac performance and exercise capacity, suggesting a distinct role of abnormal peripheral organ function, including skeletal muscle function. The impact of heart failure upon skeletal muscle and exercise performance will be discussed with a focus on molecular, structural, and functional derangements in skeletal muscle of patients with heart failure.

[Exercise training in heart failure]

In patients with chronic but stable heart failure (HF) exercise training is a recommended and widely accepted adjunct to an evidence-based management involving pharmacological and non-pharmacological therapies. Various pathophysiological mechanisms, such as central hemodynamics, vasculature, ventilation, skeletal muscle function as well as neurohormonal activation and inflammation are responsible for exercise intolerance described in HF patients. There is sufficient and growing evidence that exercise training in HF with reduced (HFrEF) and with preserved ejection fraction (HFpEF) is effective in improving exercise capacity, HF symptoms and quality of life. The positive effects of exercise training in HF are mediated by an improvement of central hemodynamics, endothelial function, inflammatory markers, neurohumoral activation, as well as skeletal muscle structure and function. In contrast to convincing data from a large meta-analysis, the large HF-ACTION study (Heart Failure-A Controlled Trial Investigating Outcomes of exercise TraiNing) only demonstrated a modest improvement of all cause mortality and hospitalizations in HFrEF. Outcome data in HFpEF are lacking. Whether interval training incorporating variable and higher intensities or the addition of resistance exercise to a standard aerobic prescription is superior in improving clinical status of HF patients is currently being examined. Despite increasing validation of the potential of exercise training in chronic HF, challenges remain in the routine therapeutic application, including interdisciplinary management, financing of long-term exercise programs and the need to improve short-term and long-term adherence to exercise training.

Exercise-based rehabilitation for heart failure

BACKGROUND

Previous systematic reviews and meta-analyses consistently show the positive effect of exercise-based rehabilitation for heart failure (HF) on exercise capacity; however, the direction and magnitude of effects on health-related quality of life, mortality and hospital admissions in HF remain less certain. This is an update of a Cochrane systematic review previously published in 2010.

OBJECTIVES

To determine the effectiveness of exercise-based rehabilitation on the mortality, hospitalisation admissions, morbidity and health-related quality of life for people with HF. Review inclusion criteria were extended to consider not only HF due to reduced ejection fraction (HFREF or 'systolic HF') but also HF due to preserved ejection fraction (HFPEF or 'diastolic HF').

SEARCH METHODS

We updated searches from the previous Cochrane review. We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (Issue1, 2013) from January 2008 to January 2013. We also searched MEDLINE (Ovid), EMBASE (Ovid), CINAHL (EBSCO) and PsycINFO (Ovid) (January 2008 to January 2013). We handsearched Web of Science, bibliographies of systematic reviews and trial registers (Controlled-trials.com and Clinicaltrials.gov).

SELECTION CRITERIA

Randomised controlled trials of exercise-based interventions with six months' follow-up or longer compared with a no exercise control that could include usual medical care. The study population comprised adults over 18 years and were broadened to include individuals with HFPEF in addition to HFREF.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened all identified references and rejected those that were clearly ineligible. We obtained full-text papers of potentially relevant trials. One review author independently extracted data from the included trials and assessed their risk of bias; a second review author checked data.

MAIN RESULTS

We included 33 trials with 4740 people with HF predominantly with HFREF and New York Heart Association classes II and III. This latest update identified a further 14 trials. The overall risk of bias of included trials was moderate. There was no difference in pooled mortality between exercise-based rehabilitation versus no exercise control in trials with up to one-year follow-up (25 trials, 1871 participants: risk ratio (RR) 0.93; 95% confidence interval (CI) 0.69 to 1.27, fixed-effect analysis). However, there was trend towards a reduction in mortality with exercise in trials with more than one year of follow-up (6 trials, 2845 participants: RR 0.88; 95% CI 0.75 to 1.02, fixed-effect analysis). Compared with control, exercise training reduced the rate of overall (15 trials, 1328 participants: RR 0.75; 95% CI 0.62 to 0.92, fixed-effect analysis) and HF specific hospitalisation (12 trials, 1036 participants: RR 0.61; 95% CI 0.46 to 0.80, fixed-effect analysis). Exercise also resulted in a clinically important improvement superior in the Minnesota Living with Heart Failure questionnaire (13 trials, 1270 participants: mean difference: -5.8 points; 95% CI -9.2 to -2.4, random-effects analysis) - a disease specific health-related quality of life measure. However, levels of statistical heterogeneity across studies in this outcome were substantial. Univariate meta-regression analysis showed that these benefits were independent of the participant's age, gender, degree of left ventricular dysfunction, type of cardiac rehabilitation (exercise only vs. comprehensive rehabilitation), mean dose of exercise intervention, length of follow-up, overall risk of bias and trial publication date. Within these included studies, a small body of evidence supported exercise-based rehabilitation for HFPEF (three trials, undefined participant number) and when exclusively delivered in a home-based setting (5 trials, 521 participants). One study reported an additional mean healthcare cost in the training group compared with control of USD3227/person. Two studies indicated exercise-based rehabilitation to be a potentially cost-effective use of resources in terms of gain in quality-adjusted life years (QALYs) and life-years saved.

AUTHORS' CONCLUSIONS

This updated Cochrane review supports the conclusions of the previous version of this review that, compared with no exercise control, exercise-based rehabilitation does not increase or decrease the risk of all-cause mortality in the short term (up to 12-months' follow-up) but reduces the risk of hospital admissions and confers important improvements in health-related quality of life. This update provides further evidence that exercise training may reduce mortality in the longer term and that the benefits of exercise training on appear to be consistent across participant characteristics including age, gender and HF severity. Further randomised controlled trials are needed to confirm the small body of evidence seen in this review for the benefit of exercise in HFPEF and when exercise rehabilitation is exclusively delivered in a home-based setting.

Effect of exercise training on left ventricular remodeling in diabetic patients with diastolic dysfunction: rationale and design

INTRODUCTION

This study will examine the effects of combined aerobic and resistance training on left ventricular remodeling in diabetic patients with diastolic dysfunction. This is the first randomized controlled trial to look for effects of combined strength training and aerobic exercise on myocardial function as well as other clinical, functional, or psychological parameters in diabetic patients with isolated diastolic dysfunction, and will provide important insights into the potential management strategies for heart failure with preserved ejection fraction.

METHODS AND ANALYSIS

This is a prospective, randomized controlled investigator initiated single center trial. Diabetic patients with LV diastolic dysfunction suitable for exercise training intervention will be randomized to three months of a supervised combination of aerobic and strength training exercises, or supervised light stretching (control arm). Pre and post intervention assessment will include stress echocardiography, peak aerobic power with 12-lead ECG, dual-energy X-ray absorptiometry, muscle strength, the capacity to perform activities of daily living (ADLs), and questionnaires to assess self-perceived quality of life and symptoms of depression. The primary endpoint is to compare any change in tissue Doppler-derived LV systolic and early diastolic velocities.

ETHICS AND DISSEMINATION

The current trial protocol has been approved by the Human Research Ethics Committee of Austin Health and the University of Melbourne, Melbourne. The study will be performed in accordance with the Declaration of Helsinki. The investigator, regardless of the outcome, will publish the results of the study.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry: ACTRN12610000943044.