The effect of physical training in chronic heart failure

Impact of exercise training on clinical outcomes and quality of life in chronic congestive heart failure: A systematic review and meta-analysis

BACKGROUND

Exercise training is a well-established intervention for patients with heart failure with reduced and preserved ejection fraction. Still, the evidence of its effects on mortality, hospitalization, and quality of life needs to be more conclusive. We aim to evaluate exercise training clinical outcomes in patients with heart failure with reduced ejection fraction (HFrEF) and heart failure with preserved ejection fraction (HFpEF).

METHODS

We searched five databases and three clinical trial registries for RCTs that compared exercise training plus usual care versus usual care alone in congestive heart failure (CHF) patients. We extracted data on all-cause mortality, hospital admission, heart failure hospitalization, and health-related quality of life measured by the Minnesota Living with HF questionnaire (MLHFW) and other scales. We pooled the data using random-effects or fixed-effects models, depending on the heterogeneity of the outcomes. We performed subgroup analyses for patients with heart failure with preserved ejection fraction (HFpEF) and heart failure with reduced ejection fraction (HFrEF).

RESULTS

We included 61 RCTs with 9062 participants. There was no mortality benefit, but exercise training improved health-related quality of life, reduced hospital admission at 12 months and longer follow-up, and reduced heart failure hospitalization. We observed substantial enhancement in health-related quality of life and a greater decrease in hospital admissions in the HFpEF group compared to the HFrEF group.

CONCLUSIONS

Despite the lack of mortality benefit, exercise training is a beneficial intervention for CHF patients, improving health-related quality of life and reducing hospitalization.

Physical Activity and Sedentary Time in US Adults with and without Heart Failure: 2007-2018 NHANES

OBJECTIVES

Current evidence describing physical activity (PA) and sedentary time (ST) in people with and without heart failure (HF) is limited. This study examines PA participation and ST in a nationally representative sample of US adults with and without self-reported HF.

METHODS

The study sample (N = 21,633) included US adult (40 years old and older) participants from the 2007-2018 National Health and Nutrition Examination Survey. PA participation, ST, and HF status were assessed via a questionnaire.

RESULTS

Compared with participants without HF (68%), 84% of participants with HF reported not meeting PA recommendations (P < 0.05). Compared with participants without HF (63%), 75% of participants with HF reported >4.5 hours/day of ST (P < 0.05). Unadjusted analysis suggests that participants with HF had 60% (P < 0.05) lower odds of reporting meeting PA recommendations when compared with those without HF. In a fully adjusted model, these odds were attenuated (odds ratio 0.74, P < 0.05). Similarly, unadjusted analysis illustrated those individuals with HF had 42% (P < 0.05) lower odds of reporting ≤4.5 hours/day of ST. In a fully adjusted model, these odds also were attenuated (odds ratio 0.66, P < 0.05).

CONCLUSIONS

Our findings suggest that US adults with HF report significantly less PA and greater amounts of ST than those without HF.

Exercise-based cardiac rehabilitation for adults with heart failure

BACKGROUND

People with heart failure experience substantial disease burden that includes low exercise tolerance, poor health-related quality of life (HRQoL), increased risk of mortality and hospital admission, and high healthcare costs. The previous 2018 Cochrane review reported that exercise-based cardiac rehabilitation (ExCR) compared to no exercise control shows improvement in HRQoL and hospital admission amongst people with heart failure, as well as possible reduction in mortality over the longer term, and that these reductions appear to be consistent across patient and programme characteristics. Limitations noted by the authors of this previous Cochrane review include the following: (1) most trials were undertaken in patients with heart failure with reduced (< 45%) ejection fraction (HFrEF), and women, older people, and those with heart failure with preserved (≥ 45%) ejection fraction (HFpEF) were under-represented; and (2) most trials were undertaken in a hospital or centre-based setting.

OBJECTIVES

To assess the effects of ExCR on mortality, hospital admission, and health-related quality of life of adults with heart failure.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, CINAHL, PsycINFO and Web of Science without language restriction on 13 December 2021. We also checked the bibliographies of included studies, identified relevant systematic reviews, and two clinical trials registers.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared ExCR interventions (either exercise only or exercise as part of a comprehensive cardiac rehabilitation) with a follow-up of six months or longer versus a no-exercise control (e.g. usual medical care). The study population comprised adults (≥ 18 years) with heart failure - either HFrEF or HFpEF.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our primary outcomes were all-cause mortality, mortality due to heart failure, all-cause hospital admissions, heart failure-related hospital admissions, and HRQoL. Secondary outcomes were costs and cost-effectiveness. We used GRADE to assess the certainty of the evidence.

MAIN RESULTS

We included 60 trials (8728 participants) with a median of six months' follow-up. For this latest update, we identified 16 new trials (2945 new participants), in addition to the previously identified 44 trials (5783 existing participants). Although the existing evidence base predominantly includes patients with HFrEF, with New York Heart Association (NYHA) classes II and III receiving centre-based ExCR programmes, a growing body of trials includes patients with HFpEF with ExCR undertaken in a home-based setting. All included trials employed a usual care comparator with a formal no-exercise intervention as well as a wide range of active comparators, such as education, psychological intervention, or medical management. The overall risk of bias in the included trials was low or unclear, and we mostly downgraded the certainty of evidence of outcomes upon GRADE assessment. There was no evidence of a difference in the short term (up to 12 months' follow-up) in the pooled risk of all-cause mortality when comparing ExCR versus usual care (risk ratio (RR) 0.93, 95% confidence interval (CI) 0.71 to 1.21; absolute effects 5.0% versus 5.8%; 34 trials, 36 comparisons, 3941 participants; low-certainty evidence). Only a few trials reported information on whether participants died due to heart failure. Participation in ExCR versus usual care likely reduced the risk of all-cause hospital admissions (RR 0.69, 95% CI 0.56 to 0.86; absolute effects 15.9% versus 23.8%; 23 trials, 24 comparisons, 2283 participants; moderate-certainty evidence) and heart failure-related hospital admissions (RR 0.82, 95% CI 0.49 to 1.35; absolute effects 5.6% versus 6.4%; 10 trials; 10 comparisons, 911 participants; moderate-certainty evidence) in the short term. Participation in ExCR likely improved short-term HRQoL as measured by the Minnesota Living with Heart Failure (MLWHF) questionnaire (lower scores indicate better HRQoL and a difference of 5 points or more indicates clinical importance; mean difference (MD) -7.39 points, 95% CI -10.30 to -4.77; 21 trials, 22 comparisons, 2699 participants; moderate-certainty evidence). When pooling HRQoL data measured by any questionnaire/scale, we found that ExCR may improve HRQoL in the short term, but the evidence is very uncertain (33 trials, 37 comparisons, 4769 participants; standardised mean difference (SMD) -0.52, 95% CI -0.70 to -0.34; very-low certainty evidence). ExCR effects appeared to be consistent across different models of ExCR delivery: centre- versus home-based, exercise dose, exercise only versus comprehensive programmes, and aerobic training alone versus aerobic plus resistance programmes.

AUTHORS' CONCLUSIONS

This updated Cochrane review provides additional randomised evidence (16 trials) to support the conclusions of the previous 2018 version of the review. Compared to no exercise control, whilst there was no evidence of a difference in all-cause mortality in people with heart failure, ExCR participation likely reduces the risk of all-cause hospital admissions and heart failure-related hospital admissions, and may result in important improvements in HRQoL. Importantly, this updated review provides additional evidence supporting the use of alternative modes of ExCR delivery, including home-based and digitally-supported programmes. Future ExCR trials need to focus on the recruitment of traditionally less represented heart failure patient groups including older patients, women, and those with HFpEF.

Exercise-based cardiac rehabilitation for adults with heart failure - 2023 Cochrane systematic review and meta-analysis

AIMS

Despite strong evidence, access to exercise-based cardiac rehabilitation (ExCR) remains low across global healthcare systems. We provide a contemporary update of the Cochrane review randomized trial evidence for ExCR for adults with heart failure (HF) and compare different delivery modes: centre-based, home-based (including digital support), and both (hybrid).

METHODS AND RESULTS

Databases, bibliographies of previous systematic reviews and included trials, and trials registers were searched with no language restrictions. Randomized controlled trials, recruiting adults with HF, assigned to either ExCR or a no-exercise control group, with follow-up of ≥6 months were included. Two review authors independently screened titles for inclusion, extracted trial and patient characteristics, outcome data, and assessed risk of bias. Outcomes of mortality, hospitalization, and health-related quality of life (HRQoL) were pooled across trials using meta-analysis at short-term (≤12 months) and long-term follow-up (>12 months) and stratified by delivery mode. Sixty trials (8728 participants) were included. In the short term, compared to control, ExCR did not impact all-cause mortality (relative risk [RR] 0.93; 95% confidence interval [CI] 0.71-1.21), reduced all-cause hospitalization (RR 0.69; 95% CI 0.56-0.86, number needed to treat: 13, 95% CI 9-22), and was associated with a clinically important improvement in HRQoL measured by the Minnesota Living with Heart Failure Questionnaire (MLWHF) overall score (mean difference: -7.39; 95% CI -10.30 to -4.47). Improvements in outcomes with ExCR was seen across centre, home (including digitally supported), and hybrid settings. A similar pattern of results was seen in the long term (mortality: RR 0.87, 95% CI 0.72-1.04; all-cause hospitalization: RR 0.84, 95% CI 0.70-1.01, MLWHF: -9.59, 95% CI -17.48 to -1.50).

CONCLUSIONS

To improve global suboptimal levels of uptake for HF patients, global healthcare systems need to routinely recommend ExCR and offer a choice of mode of delivery, dependent on an individual patient's level of risk and complexity.

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

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

Cardiac rehabilitation for heart failure and atrial fibrillation: a propensity- matched study

BACKGROUND

Atrial fibrillation (AF) is common in individuals with heart failure (HF). Individuals with HF and AF may have a reduced functional capacity and quality of life (QoL) which leads to hospital admission and burden on clinical services. Evidence supported the effect of exercise training in individuals with HF. However, there is no existing data on the effectiveness of comprehensive cardiac rehabilitation (CR) in individuals with coexisting HF and AF.

AIM

To explore the effect of CR in individuals with HF and AF compared with those with HF and no-coexisting AF.

METHODS

Using CR database, individuals with HF and AF were identified and propensity matched to those with no coexisting AF. The change in incremental shuttle walking test, Heart Disease Quality of Life questionnaire, Hospital Anxiety and Depression Scores were compared between groups pre-CR and post-CR.

RESULTS

149 individuals were propensity matched from each group. The mean±SD age of the matched sample was 73.4±8 years, body mass index 29±5.5 kg/m2, left ventricular ejection fraction 35.2±9.8% and 56% were male.A statistically significant improvements in exercise capacity, heart disease QoL, anxiety and depression scores were observed within each group. There were no significant differences between groups for any of these outcome measures.

CONCLUSIONS

Individuals with HF and AF gain a similar improvement in exercise capacity and health related QoL outcomes as individuals with no coexisting AF following CR. The presence of AF did not compromise the effectiveness of CR.

Meta-Analysis of Physical Training on Natriuretic Peptides and Inflammation in Heart Failure

Physical training has been reported to attenuate myocardial stress and inflammation in heart failure (HF). We aimed to assess the impact of physical training on B-type natriuretic peptide and N-terminal pro-B-type natriuretic peptide (NT-proBNP), as well as biomarkers of inflammation-C-reactive protein, tumor necrosis factor α (TNF-α), and interleukins (ILs). A systematic electronic literature search was conducted up to May 2021 in PubMed, Cochrane Library, CINAHL, Embase, and SPORTDiscus to identify randomized clinical trials reporting associations between any formal physical training intervention and biomarker levels in patients with HF. Random-effects meta-analyses was used to calculate pooled correlations between physical training and blood biomarkers. Biomarker outcomes were expressed as mean difference or ratio of means and 95% confidence interval between the intervention and control groups, according to the normality of the data. A total of 38 trials were included in the final meta-analysis (2,652 randomized patients). Physical training was associated with decreased B-type natriuretic peptide (p = 0.02), NT-proBNP (p <0.01), C-reactive protein (p <0.00001), TNF-α (p = 0.03), IL-6 (p = 0.04), and IL-1β (p = 0.001). Aerobic continuous training was associated with a 35% reduction in NT-proBNP (p = 0.01); ≥150 min/week of exercise was associated with a greater reduction in TNF-α levels (p = 0.0004), and aerobic interval training was associated with lower IL-6 levels (p = 0.01). In conclusion, physical training in patients with HF is associated with beneficial effects on natriuretic peptides and biomarkers of inflammation because they were all reduced by the intervention.

Effects of exercise-based cardiac rehabilitation delivery modes on exercise capacity and health-related quality of life in heart failure: a systematic review and network meta-analysis

Background

This review aimed to compare the relative effectiveness of different exercise-based cardiac rehabilitation (ExCR) delivery modes (centre-based, home-based, hybrid and technology-enabled ExCR) on key heart failure (HF) outcomes: exercise capacity, health-related quality of life (HRQoL), HF-related hospitalisation and HF-related mortality.

Methods and results

Randomised controlled trials (RCTs) published through 20 June 2021 were identified from six databases, and reference lists of included studies. Risk of bias and certainty of evidence were evaluated using the Cochrane tool and Grading of Recommendations Assessment, Development and Evaluation, respectively. Bayesian network meta-analysis was performed using R. Continuous and binary outcomes are reported as mean differences (MD) and ORs, respectively, with 95% credible intervals (95% CrI). One-hundred and thirty-nine RCTs (n=18 670) were included in the analysis. Network meta-analysis demonstrated improvements in VO₂peak following centre-based (MD (95% CrI)=3.10 (2.56 to 3.65) mL/kg/min), home-based (MD=2.69 (1.67 to 3.70) mL/kg/min) and technology-enabled ExCR (MD=1.76 (0.27 to 3.26) mL/kg/min). Similarly, 6 min walk distance was improved following hybrid (MD=84.78 (31.64 to 138.32) m), centre-based (MD=50.35 (30.15 to 70.56) m) and home-based ExCR (MD=36.77 (12.47 to 61.29) m). Incremental shuttle walk distance did not improve following any ExCR delivery modes. Minnesota living with HF questionnaire improved after centre-based (MD=−10.38 (−14.15 to –6.46)) and home-based ExCR (MD=−8.80 (−13.62 to –4.07)). Kansas City Cardiomyopathy Questionnaire was improved following home-based ExCR (MD=20.61 (4.61 to 36.47)), and Short Form Survey 36 mental component after centre-based ExCR (MD=3.64 (0.30 to 6.14)). HF-related hospitalisation and mortality risks reduced only after centre-based ExCR (OR=0.41 (0.17 to 0.76) and OR=0.42 (0.16 to 0.90), respectively). Mean age of study participants was only associated with changes in VO₂peak.

Conclusion

ExCR programmes have broader benefits for people with HF and since different delivery modes were comparably effective for improving exercise capacity and HRQoL, the selection of delivery modes should be tailored to individuals’ preferences.

Physical Rehabilitation in Older Patients Hospitalized with Acute Heart Failure and Diabetes: Insights from REHAB-HF

BACKGROUND

Prior studies showed an attenuated response to exercise training among patients with heart failure and type 2 diabetes mellitus. We explored the interaction between diabetes status and a novel, transitional, tailored, progressive rehabilitation intervention that improved physical function compared with usual care in the Rehabilitation Therapy in Older Acute Heart Failure Patients (REHAB-HF) trial.

METHODS

The effect of the intervention on 3-month Short Physical Performance Battery (SPPB) (primary endpoint), 6-minute walk distance (6MWD), modified Fried frailty criteria, and quality-of-life scores (Kansas City Cardiomyopathy Questionnaire [KCCQ] and EuroQoL Visual Analogue Scale [VAS]) was compared between participants with and without diabetes. Differences in 6-month clinical outcomes were also explored.

RESULTS

Of the 349 participants enrolled in REHAB-HF, 186 (53%) had diabetes. The prevalence of diabetes was higher in the intervention group (59% vs 48%). Participants with diabetes had worse baseline physical function by the SPPB and 6MWD, but similar frailty and quality-of-life scores. There was a consistent improvement with the intervention for 3-month SPPB, 6MWD, and VAS regardless of diabetes status (all interaction P value > .6), but participants with diabetes had significantly less improvement for frailty (P = .021) and a trend toward lower improvement in KCCQ (P = .11). There was no significant interaction by diabetes status for 6-month clinical event outcomes (all interaction P value > .3).

CONCLUSIONS

Participants with diabetes had worse baseline physical function but showed similar clinically meaningful improvements from the intervention. There was less benefit for frailty with the intervention in participants with diabetes.

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

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

Combined aerobic and strength training for fitness outcomes in heart failure: meta-analysis and meta-regression

PURPOSE

To compare the effects of combined training (CT) versus aerobic training (AT) or versus control on VO₂ peak and quadriceps muscle strength in patients with heart failure (HF).

MATERIALS AND METHODS

Major electronic databases were searched, from inception to November 2020, for randomized clinical trials comparing the effects of CT against AT or control on VO₂ peak and/or quadriceps muscle strength in patients with HF. Random effects meta-analyses were conducted, calculating the standardized mean difference (SMD).

RESULTS

Twenty-eight articles were included. An increase on VO₂ peak (SMD = 0.77, 95%CI 0.39-1.14, I²=80.1%) and quadriceps muscle strength (SMD = 0.67, 95%CI 0.18-1.16, I²=0%) was found in CT compared to control. CT increased quadriceps muscle strength, versus AT (SMD = 0.44, 95%CI 0.15-0.74, I²=0%). There were no differences between CT and AT on VO₂ peak (SMD=-0.01, 95%CI -0.36 to 0.34, I²=65%). Time of session and training duration moderate the effects of CT over control on VO₂ peak.

CONCLUSIONS

CT promotes increases on quadriceps muscle strength and aerobic capacity over control and provides additional gains on quadriceps muscle strength, having the same effects on VO₂ peak compared to AT. A longer time of session is associated with greater benefits to aerobic capacity.Implications for rehabilitationCombining aerobic and strength training increases the functional capacity and quadriceps muscle strength in heart failure patients.Using longer sessions of training has a greater impact on aerobic capacity.

Skeletal muscle atrophy in heart failure with diabetes: from molecular mechanisms to clinical evidence

Two highly prevalent and growing global diseases impacted by skeletal muscle atrophy are chronic heart failure (HF) and type 2 diabetes mellitus (DM). The presence of either condition increases the likelihood of developing the other, with recent studies revealing a large and relatively poorly characterized clinical population of patients with coexistent HF and DM (HFDM). HFDM results in worse symptoms and poorer clinical outcomes compared with DM or HF alone, and cardiovascular-focused disease-modifying agents have proven less effective in HFDM indicating a key role of the periphery. This review combines current clinical knowledge and basic biological mechanisms to address the critical emergence of skeletal muscle atrophy in patients with HFDM as a key driver of symptoms. We discuss how the degree of skeletal muscle wasting in patients with HFDM is likely underpinned by a variety of mechanisms that include mitochondrial dysfunction, insulin resistance, inflammation, and lipotoxicity. Given many atrophic triggers (e.g. ubiquitin proteasome/autophagy/calpain activity and supressed IGF1-Akt-mTORC1 signalling) are linked to increased production of reactive oxygen species, we speculate that a higher pro-oxidative state in HFDM could be a unifying mechanism that promotes accelerated fibre atrophy. Overall, our proposal is that patients with HFDM represent a unique clinical population, prompting a review of treatment strategies including further focus on elucidating potential mechanisms and therapeutic targets of muscle atrophy in these distinct patients.

Cardiac Rehabilitation in Heart Failure

Heart failure (HF) is a complex clinical syndrome caused by a structural and/or functional cardiac abnormality, resulting in reduced organ perfusion. The goals of treatment in patients with HF are to improve functional capacity and quality of life, and to reduce mortality. Cardiac rehabilitation (CR) including exercise training is one of the treatment options, and current guidelines recommend CR as safe and effective for patients with HF. CR has been known to improve exercise capacity and quality of life, minimize HF progression, and lower mortality in patients with HF. Improvement of vascular endothelial function, activation of the neurohormonal system, increase of mitochondrial oxygen utilization in peripheral muscles, and increase of chronotropic responses are possible mechanisms of the beneficial effects of exercise-based CR in HF. Although CR has been shown to decrease morbidity and mortality, it is underutilized in clinical practice. Despite the existence of concrete evidence of clinical benefits, the CR participation rates of patients with HF range from only 14% to 43% worldwide, with high dropout rates after enrollment. These low participation rates have been attributed to several barriers, including patient factors, professional factors, and service factors. The motivation for participating in CR and for overcoming the patients' barriers for CR before discharge should be provided to each patient. Current guidelines strongly recommend applying a CR program to all eligible patients with HF.

Endurance Exercise Training Prevents Elevation of Soluble ST2 in Mice with Doxorubicin-Induced Myocardial Injury

Background and Objectives

Endurance exercise training (ET) can improve outcomes for patients with heart failure (HF). We investigated the preventive effects of ET on serum biomarkers for HF in mice treated with doxorubicin (DOX).

Methods

A cohort of male wild-type mice were randomly assigned to 3 groups: sedentary control (CON), DOX-treated sedentary (DOX), and DOX-treated endurance ET (ET-DOX) groups. ET groups performed moderate intensity endurance ET on a motor treadmill for 8 weeks. After 8 weeks, the DOX and ET-DOX groups were treated with DOX via weekly intraperitoneal injections of 8 mg/kg for a total of 4 weeks. We compared M-mode echocardiography, histology, and biomarkers for HF between groups.

Results

A total of 30 mice survived during the study period and were analyzed: CON (n=9), DOX (n=9) and ET-DOX (n=12). There was no significant difference in left ventricular ejection fraction (LVEF) or fractional shortening (FS) between DOX and ET-DOX groups. The ET-DOX group had a significantly lower soluble ST2 level (176.6±44.1 vs. 225.4±60.5 pg/mL, p=0.021) compared to the DOX group. Also similar between the ET-DOX and the DOX groups were the serum N-terminal prohormone of brain natriuretic peptide (30.3±12.5 vs. 34.0±21.7 pg/mL, p=0.849), troponin I (685.7±99.2 vs. 722.5±126.7 pg/mL, p=0.766), and neutrophil gelatinase-associated lipocalin (324.3±82.4 vs. 312.7±68.2 pg/mL, p=0.922) levels. Histologically, there was no significant difference in degree of perivascular fibrosis between DOX and ET-DOX groups.

Conclusions

Endurance ET is effective for preventing increases in serum soluble ST2 in mice treated with DOX.

Comparison of the effect of 12- and 24-session cardiac rehabilitation on physical, psychosocial and biomedical factors in ischemic heart disease patients

Background Cardiac rehabilitation (CR) is a key component of effective care for patients with a wide spectrum of cardiac problems. It seems that the short-term provision of these services can facilitate their use and meeting of related needs for patients participating in the CR programs. Materials and methods In this interventional study on patients with ischemic heart disease (IHD) referred to the Cardiac Rehabilitation Center of Chamran Hospital, Isfahan, Iran. One-hundred and twelve patients were randomly divided into two groups of 12 and 24 sessions of CR [mean age: 59.2 ± (9.02) and 60.7 ± (9.3) years, respectively] and underwent a CR program. All information was collected in two stages, before the beginning of the program and after completion of 12- and 24-session rehabilitation programs. The data collection tools were demographics questionnaire, the International Physical Activity Questionnaires (IPAQ), McNew Quality of Life Questionnaire, Beck Depression Inventory (BDI), and Zung Self-Rating Anxiety Scale (SAS). Results The results of this study showed that in both groups, total physical activity (PA) and functional capacity increased, and the quality of life (QOL) was statistically improved. Comparison of changes in mean differences at the end of the rehabilitation periods between the two groups, showed that only the weight, body mass index (BMI), waist circumference (WC) and high-density lipoprotein (HDL) in the 24-session group significantly decreased compared to the 12-session group and, but no significant difference in other variables was observed. Conclusion Overall, the findings of this study support the overall benefits of the CR program in both the short and the long term. Therefore it can be suggested that a short-term program can still be a valuable option for reducing the risk in cardiac patients and meeting their service needs.

Exercise intolerance and fatigue in chronic heart failure: is there a role for group III/IV afferent feedback?

Exercise intolerance and early fatiguability are hallmark symptoms of chronic heart failure. While the malfunction of the heart is certainly the leading cause of chronic heart failure, the patho-physiological mechanisms of exercise intolerance in these patients are more complex, multifactorial and only partially understood. Some evidence points towards a potential role of an exaggerated afferent feedback from group III/IV muscle afferents in the genesis of these symptoms. Overactivity of feedback from these muscle afferents may cause exercise intolerance with a double action: by inducing cardiovascular dysregulation, by reducing motor output and by facilitating the development of central and peripheral fatigue during exercise. Importantly, physical inactivity appears to affect the progression of the syndrome negatively, while physical training can partially counteract this condition. In the present review, the role played by group III/IV afferent feedback in cardiovascular regulation during exercise and exercise-induced muscle fatigue of healthy people and their potential role in inducing exercise intolerance in chronic heart failure patients will be summarised.

The role of cardiac rehabilitation using exercise to decrease natriuretic peptide levels in non-surgical patients: a systematic review

Exercise is recommended in patients with cardiac failure. In the perioperative patient, exercise is also gaining popularity as a form of prehabilitation. In this meta-analysis, we examine if exercise is able to reduce natriuretic peptide levels. Natriuretic peptide (NP) has strong prognostic ability in identifying patients who will develop adverse postoperative cardiovascular outcomes. The protocol was registered with PROSPERO (CRD42017051468). The database search included MEDLINE (PubMed), CINAHL (EBSCO host), EMBASE (EBSCO host), ProQuest, Web of Science, and Cochrane database. The primary outcomes were to determine whether exercise therapy was effective in reducing NP levels as compared to control group, the shortest time period required to reduce NP levels after exercise therapy, and whether reducing NP levels decreased morbidity and mortality. Full texts of 16 trials were retrieved for this review. Exercise therapy showed a significant reduction in natriuretic peptide levels between the intervention and control groups (SMD - 0.45, 95% CI - 0.88 to - 0.03) with significant heterogeneity between the included trials. This was also shown in the within a 12-week period.

Comparison of functional and maximal exercise capacity, respiratory and peripheral muscle strength, dyspnea, and fatigue in patients with heart failure with pacemakers and healthy controls: a cross-sectional study

Background: Despite major breakthroughs that have recently been made in pacemakers implanted in patients with heart failure (HF), it is clear that functional impairments and symptoms often remain. However, only limited studies have investigated exercise capacity, muscle strength, pulmonary function, dyspnea, and fatigue in these patients. Therefore, we aimed to compare aforementioned outcomes in patients and healthy controls. Methods: A cross-sectional study. Fifty patients with HF with pacemakers (58.90 ± 10.69 years, NYHA II-III, LVEF: 30.79 ± 8.78%) and 40 controls (56.33 ± 5.82 years) were compared. Functional (6-Minute Walking test (6-MWT)) and maximal exercise capacity (Incremental Shuttle Walk test (ISWT)), respiratory (Mouth pressure device) and peripheral muscle strength (Dynamometer), pulmonary function (Spirometry), dyspnea (Modified Medical Research Council Dyspnea scale), and fatigue (Fatigue Severity scale) were evaluated. ClinicalTrial number: NCT03701854. Results: 6-MWT (412.62 ± 96.51 m versus 610.16 ± 59.48 m) and ISWT (279.97 m versus 655 m) distances (p ˂ 0.001), pulmonary function (p˂0.001), respiratory and peripheral muscle strength (p ˂ 0.001) were significantly lower; dyspnea (p ˂ 0.001) and fatigue (p = .030) scores were higher in patients compared with controls. Conclusion: Maximal and functional exercise capacity is impaired in the majority of patients with HF with pacemakers, respiratory and peripheral muscles are weakened, dyspnea and fatigue perceptions are increased. Patients with pacemakers have to be included in cardiac rehabilitation programs to improve impairments.

Exercise-based cardiac rehabilitation for adults with heart failure

BACKGROUND

Chronic heart failure (HF) is a growing global health challenge. People with HF experience substantial burden that includes low exercise tolerance, poor health-related quality of life (HRQoL), increased risk of mortality and hospital admission, and high healthcare costs. The previous (2014) Cochrane systematic review reported that exercise-based cardiac rehabilitation (CR) compared to no exercise control shows improvement in HRQoL and hospital admission among people with HF, as well as possible reduction in mortality over the longer term, and that these reductions appear to be consistent across patient and programme characteristics. Limitations noted by the authors of this previous Cochrane Review include the following: (1) most trials were undertaken in patients with HF with reduced (< 45%) ejection fraction (HFrEF), and women, older people, and those with preserved (≥ 45%) ejection fraction HF (HFpEF) were under-represented; and (2) most trials were undertaken in the hospital/centre-based setting.

OBJECTIVES

To determine the effects of exercise-based cardiac rehabilitation on mortality, hospital admission, and health-related quality of life of people with heart failure.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, and three other databases on 29 January 2018. We also checked the bibliographies of systematic reviews and two trial registers.

SELECTION CRITERIA

We included randomised controlled trials that compared exercise-based CR interventions with six months' or longer follow-up versus a no exercise control that could include usual medical care. The study population comprised adults (> 18 years) with evidence of HF - either HFrEF or HFpEF.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened all identified references and rejected those that were clearly ineligible for inclusion in the review. We obtained full papers of potentially relevant trials. Two review authors independently extracted data from the included trials, assessed their risk of bias, and performed GRADE analyses.

MAIN RESULTS

We included 44 trials (5783 participants with HF) with a median of six months' follow-up. For this latest update, we identified 11 new trials (N = 1040), in addition to the previously identified 33 trials. Although the evidence base includes predominantly patients with HFrEF with New York Heart Association classes II and III receiving centre-based exercise-based CR programmes, a growing body of studies include patients with HFpEF and are undertaken in a home-based setting. All included studies included a no formal exercise training intervention comparator. However, a wide range of comparators were seen across studies that included active intervention (i.e. education, psychological intervention) or usual medical care alone. The overall risk of bias of included trials was low or unclear, and we downgraded results using the GRADE tool for all but one outcome.Cardiac rehabilitation may make little or no difference in all-cause mortality over the short term (≤ one year of follow-up) (27 trials, 28 comparisons (2596 participants): intervention 67/1302 (5.1%) vs control 75/1294 (5.8%); risk ratio (RR) 0.89, 95% confidence interval (CI) 0.66 to 1.21; low-quality GRADE evidence) but may improve all-cause mortality in the long term (> 12 months follow up) (6 trials/comparisons (2845 participants): intervention 244/1418 (17.2%) vs control 280/1427 (19.6%) events): RR 0.88, 95% CI 0.75 to 1.02; high-quality evidence). Researchers provided no data on deaths due to HF. CR probably reduces overall hospital admissions in the short term (up to one year of follow-up) (21 trials, 21 comparisons (2182 participants): (intervention 180/1093 (16.5%) vs control 258/1089 (23.7%); RR 0.70, 95% CI 0.60 to 0.83; moderate-quality evidence, number needed to treat: 14) and may reduce HF-specific hospitalisation (14 trials, 15 comparisons (1114 participants): (intervention 40/562 (7.1%) vs control 61/552 (11.1%) RR 0.59, 95% CI 0.42 to 0.84; low-quality evidence, number needed to treat: 25). After CR, a clinically important improvement in short-term disease-specific health-related quality of life may be evident (Minnesota Living With Heart Failure questionnaire - 17 trials, 18 comparisons (1995 participants): mean difference (MD) -7.11 points, 95% CI -10.49 to -3.73; low-quality evidence). Pooling across all studies, regardless of the HRQoL measure used, shows there may be clinically important improvement with exercise (26 trials, 29 comparisons (3833 participants); standardised mean difference (SMD) -0.60, 95% CI -0.82 to -0.39; I² = 87%; Chi² = 215.03; low-quality evidence). ExCR effects appeared to be consistent different models of ExCR delivery: centre vs. home-based, exercise dose, exercise only vs. comprehensive programmes, and aerobic training alone vs aerobic plus resistance programmes.

AUTHORS' CONCLUSIONS

This updated Cochrane Review provides additional randomised evidence (11 trials) to support the conclusions of the previous version (2014) of this Cochane Review. Compared to no exercise control, CR appears to have no impact on mortality in the short term (< 12 months' follow-up). Low- to moderate-quality evidence shows that CR probably reduces the risk of all-cause hospital admissions and may reduce HF-specific hospital admissions in the short term (up to 12 months). CR may confer a clinically important improvement in health-related quality of life, although we remain uncertain about this because the evidence is of low quality. Future ExCR trials need to continue to consider the recruitment of traditionally less represented HF patient groups including older, female, and HFpEF patients, and alternative CR delivery settings including home- and using technology-based programmes.

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

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

BDNF contributes to the skeletal muscle anti-atrophic effect of exercise training through AMPK-PGC1α signaling in heart failure mice

INTRODUCTION

Exercise training is a coadjuvant therapy in preventive cardiology, and it delays cardiac dysfunction and exercise intolerance in heart failure (HF). However, the mechanisms underlying muscle function improvement and cardioprotection are poorly understood. In this study, we tested whether exercise training would counteract skeletal muscle atrophy via activation of the BDNF pathway in myocardial infarction (MI)-induced HF mice.

MATERIAL AND METHODS

A cohort of male Sham-operated and MI mice were assigned into 8-week moderate exercise training, and untrained counterparters were used as control. Exercise capacity, plasma norepinephrine (NE) level, heart rate (HR), fractional shortening (FS) and ejection fraction (EF) were measured. The protein expression of BDNF, p-TrkB, p-AMPK and PGC1α were analyzed by Western blot.

RESULTS

Compared with the Sham-operated mice, MI mice displayed reduced total distance run and elevated plasma NE level (both p < 0.05). Exercise training significantly improved distance run and plasma NE levels in HF mice (both p < 0.05). Significantly increased HR, decreased FS and EF were observed in the MI group as compared to the Sham-operated group, and exercise training prevent the hemodynamic status and systolic dysfunction in MI mice (all p < 0.05). The expression of BDNF, p-TrkB, p-AMPK and PGC1α were significantly decreased in the skeletal muscle from MI compared to Sham-operated mice, which were significantly increased by exercise training (all p < 0.05). In addition, BDNF siRNA markedly decreased the protein level of p-AMPK and PGC1α in C2C12 myoblasts.

CONCLUSIONS

Taken together, our data provide evidence for exercise training may counteract HF-induced muscle atrophy through induced activation of BDNF pathway.

Effect of exercise therapy on established and emerging circulating biomarkers in patients with heart failure: a systematic review and meta-analysis

Background

Biomarkers are important in the diagnosis, risk stratification and management of patients with heart failure (HF). The established biomarkers of myocardial stretch, brain natriuretic peptide (BNP) and amino (N) portion of BNP (NT-proBNP) have been extensively studied, and early analyses have demonstrated response to exercise training. Several other biomarkers have been identified over the last decade and may provide valuable and complementary information which may guide treatment strategies, including exercise therapy.

Methods

A systematic search of PubMed, EMBASE and Cochrane Trials Register to 31 October 2017 was conducted for exercise-based rehabilitation trials in HF. Randomised and controlled trials that reported biomarkers, BNP, NT-proBNP, soluble ST2, galectin-3, mid-regional atrial natriuretic peptide, mid-regional adrenomedullin and copeptin, were included.

Results

Forty-three studies were included in the systematic review, with 27 studies suitable for meta-analyses. Data pooling was only possible for NT-proBNP and BNP. Meta-analyses of conventional training studies demonstrated a statistically significant improvement in NT-proBNP (pmol/L); mean difference (MD) −32.80 (95% CI −56.19 to −9.42), p=0.006 and in BNP (pmol/L); MD −17.17 (95% CI −29.56 to −4.78), p=0.007. Pooled data of non-conventional training failed to demonstrate any statistically significant improvements.

Conclusion

Pooled data indicated a favourable effect of conventional exercise therapy on the established biomarkers, NT-proBNP and BNP; however, this was in contrast to a number of studies that could not be pooled. Limited evidence exists as to the effect of exercise training on emerging biomarkers.

Dose-Response Relationship Between Exercise Intensity, Mood States, and Quality of Life in Patients With Heart Failure

BACKGROUND

We conducted a secondary analysis to (1) compare changes in mood disorders and quality of life (QOL) among 4 groups of patients with heart failure in a home-based exercise program who had varying degrees of change in their exercise capacity and (2) determine whether there was an association between exercise capacity, mood disorders, and QOL.

METHODS

Seventy-one patients were divided into 4 groups based on changes in exercise capacity from baseline to 6 months: group 1showed improvements of greater than 10% (n = 19), group 2 showed improvements of 10% or less (n = 16), group 3 showed reductions of 10% or less (n = 9), and group 4 showed reductions of greater than 10% (n = 27).

RESULTS

Over time, patients in all 4 groups demonstrated significantly lower levels of depression and hostility (P < .001) and higher levels of physical and overall quality of life (P = .046). Group differences over time were noted in anxiety (P = .009), depression (P = .015), physical quality of life (P < .001), and overall quality of life (P = .002). Greater improvement in exercise capacity was strongly associated with lower depression scores (r = -0.49, P = .01).

CONCLUSIONS

An improvement in exercise capacity with exercise training was associated with a decrease in depression and anxiety and an increase in QOL in patients with heart failure.

Exercise for Preventing Hospitalization and Readmission in Adults With Congestive Heart Failure

We critically appraised all available evidence regarding exercise interventions for improving patient survival and reducing hospital admissions in adults with chronic heart failure (HF). We searched 4 databases up to April 2018 and graded the quality of evidence according to the Grading of Recommendations Assessment, Development and Evaluation working group approach. We reviewed 7 meta-analyses and the publications of 48 randomized controlled trials (RCTs). In HF with reduced ejection fraction, low-quality evidence suggests that exercise prevents all-cause hospitalizations [Relative risk (RR), 0.77; 95% confidence interval (CI), 0.63 to 0.93; 1328 patients in 15 RCTs] and hospitalizations due to HF (RR, 0.57; 95% CI, 0.37 to 0.88; 1073 patients in 13 RCTs) and improves quality of life (standardized mean difference, -0.37; 95% CI, -0.60 to -0.14; 1270 patients in 25 RCTs) but has no effect on mortality. In HF with preserved ejection fraction, low-quality evidence suggests that exercise improves peak oxygen uptake (mean difference, 2.36; 95% CI, 1.16 to 3.57; 171 patients in 3 RCTs) and quality of life (mean difference, -4.65; 95% CI, -8.46 to -0.83; 203 patients in 4 RCTs). In patients after heart transplantation, low-quality evidence suggests that exercise improves peak oxygen uptake (standardized mean difference, 0.68; 95% CI, 0.43 to 0.93; 284 patients in 9 RCTs) but does not improve quality of life. In order to reduce hospitalization and improve quality of life for adults with HF and reduced ejection fraction, clinicians should recommend exercise interventions. For adults with HF and preserved ejection fraction and in those undergoing heart transplantation, clinicians may recommend exercise interventions in order to improve peak oxygen uptake.

Efficacy of combined endurance-resistance training versus endurance training in patients with heart failure after percutaneous coronary intervention: A randomized controlled trial

Background:

This study aimed to compare the effects of combined endurance-resistance training (CT) versus endurance training (ET) on some cardiovascular markers in patients with heart failure after percutaneous coronary intervention (PCI).

Materials and Methods:

The study applied a randomized, controlled design in which 75 patients with heart failure who had undergone PCI were randomly assigned to one of three groups: ET, CT, and control. The ET group performed ET for 45 min, three times a week for 7 weeks. The CT group performed the same ET for 30 min followed by a resistance exercise protocol. The control group received usual care. Functional capacity, N-terminal pro-brain natriuretic peptide (NT-pro BNP), and high sensitivity C-reactive protein (hs-CRP) levels were measured.

Results:

After the intervention, functional capacity was improved (P < 0.001) and NT-pro BNP level was significantly reduced (P = 0.004 in the CT group, P = 0.002 in the ET group). Hs-CRP level was significantly reduced only in the ET group (P = 0.030). The control group showed no significant changes in any cardiovascular parameters (P ≥ 0.05). Changes in functional capacity (P < 0.001) in both training groups were significantly different from the control group. No significant differences were found between the ET and CT groups regarding changes in all outcomes after exercise training (P ≥ 0.05).

Conclusion:

Exercise training is safe and feasible in post-PCI patients, even in those with reduced ejection fraction. CT was as effective as ET in reducing NT-pro BNP level and improving functional capacity in heart failure patients after PCI.

Effect of short-term exercise intervention on cardiovascular functions and quality of life of chronic heart failure patients: A meta-analysis

OBJECTIVE

The purpose of this study was to comprehensively evaluate the effect of short-term exercise intervention on the cardiovascular functions and quality of life (QoL) of patients with chronic heart failure (CHF).

METHODS

This meta-analysis was analyzed using RevMan5.3 and Stata 13.0. The parameters of cardiovascular functions and QoL were assessed. Weighted mean differences and their corresponding 95% confidence intervals (CIs) were computed for continuous variables.

RESULTS

Data from 2533 CHF patients enrolled in 28 published studies of randomized controlled trials (RCTs) were collated. There were significant differences in VO2 max prior to and after exercise intervention in CHF patients who are 50-55 years old (5 RCTs; 95% CI, -4.86 to -2.29; I2 = 50.5%), 60-65 years old (10 RCTs; 95% CI, -2.66 to -2.04; I2 = 0%), and 69-75 years old (5 RCTs; 95% CI, -1.88 to -0.34; I2 = 38.5%). VO2 max was significantly increased by aerobic exercise (9 RCTs; 95% CI, -3.45 to -1.92; I2 = 37.7%) and combined aerobic resistance exercise (4 RCTs; 95% CI, -4.41 to -0.26; I2 = 76.6%). There were significant differences in cardiac output (n = 303; 95% CI, -0.25 to -0.02; I2 = 12%) and QoL (n = 299; 95% CI, 3.19 to 9.70; I2 = 17%) prior to and after short-term exercise.

CONCLUSION

Aerobic exercise and aerobic with resistance exercise can significantly improve the aerobic capacity of CHF patients, whereas resistance exercise cannot. The improvement in aerobic capacity caused by aerobic exercise and aerobic with resistance exercise decreases with age. Systolic blood pressure and ventricle structures and functions of CHF patients show no significant changes after the short-term exercise intervention.

Aerobic Exercise and Pharmacological Therapies for Skeletal Myopathy in Heart Failure: Similarities and Differences

Skeletal myopathy has been identified as a major comorbidity of heart failure (HF) affecting up to 20% of ambulatory patients leading to shortness of breath, early fatigue, and exercise intolerance. Neurohumoral blockade, through the inhibition of renin angiotensin aldosterone system (RAS) and β-adrenergic receptor blockade (β-blockers), is a mandatory pharmacological therapy of HF since it reduces symptoms, mortality, and sudden death. However, the effect of these drugs on skeletal myopathy needs to be clarified, since exercise intolerance remains in HF patients optimized with β-blockers and inhibitors of RAS. Aerobic exercise training (AET) is efficient in counteracting skeletal myopathy and in improving functional capacity and quality of life. Indeed, AET has beneficial effects on failing heart itself despite being of less magnitude compared with neurohumoral blockade. In this way, AET should be implemented in the care standards, together with pharmacological therapies. Since both neurohumoral inhibition and AET have a direct and/or indirect impact on skeletal muscle, this review aims to provide an overview of the isolated effects of these therapeutic approaches in counteracting skeletal myopathy in HF. The similarities and dissimilarities of neurohumoral inhibition and AET therapies are also discussed to identify potential advantageous effects of these combined therapies for treating HF.

Physiological basis of cardiopulmonary rehabilitation in patients with lung or heart disease

Educational Aims

Summary

Shortness of breath associated with cardiorespiratory abnormalities and peripheral muscle discomfort are the major factors that limit exercise capacity in patients with chronic obstructive pulmonary disease (COPD) and those with congestive heart failure (CHF). Both of these symptoms negatively impact on patients’ daily physical activity levels. In turn, poor daily physical activity is commonly associated with increased rates of morbidity and mortality. Cardiopulmonary rehabilitation programmes partially reverse muscle weakness and dysfunction and increase functional capacity in both COPD and CHF. However, benefits gained from participation in cardiopulmonary rehabilitation programmes are regressing soon after the completion of these programmes. Moreover, several barriers limit access and uptake of cardiopulmonary rehabilitation programmes by eligible patients. A potential solution to the underutilisation of cardiopulmonary rehabilitation is the implementation of tele-rehabilitation interventions at home using information and communications technologies. Thus, tele-rehabilitation may be useful to encourage and educate patients with COPD or CHF on how best to maintain and/or further enhance daily physical activity levels.

Aerobic exercise effect on prognostic markers for systolic heart failure patients: a systematic review and meta-analysis

From previous systematic reviews and meta-analyses, there is consensus about the positive effect of exercise training on exercise capacity for systolic heart failure (HF); however, the effect on actual prognostic markers such as NTproBNP and minute ventilation/carbon dioxide production (VE/VCO2) slope has not been evaluated. The primary aim of the proposed study is to determine the effect of aerobic exercise training (AEX) on the VE/VCO2 slope and NTproBNP. The following databases (up to February 30, 2013) were searched with no language limitations: CENTRAL (The Cochrane Library 2013, issue 2), MEDLINE (from January 1966), EMBASE (from January 1980), and Physiotherapy Evidence Database (PEDro) (from January 1929). We screened reference lists of articles and also conducted an extensive hand search of the literature. Randomized controlled trials of exercise-based interventions with 2-month follow-up or longer compared to usual medical care or placebo were included. The study population comprised adults aged between 18 and 65 years, with evidence of chronic systolic heart failure (LVEF < 45 % and baseline NTproBNP > 300 pg/ml). Two review authors independently extracted data on study design, participants, interventions, and outcomes. We assessed the risk of bias using PEDro scale. We calculated mean differences (MD) or standardized mean differences between intervention and control groups for outcomes with sufficient data; for other outcomes, we described findings from individual studies. Eight studies involving a total of 408 participants met the inclusion criteria across the NTproBNP (5 studies with 191 patients) and VE/VCO2 slope (4 studies with 217 patients). Aerobic exercise significantly improved NTproBNP by a MD of -817.75 [95 % confidence interval (CI) -929.31 to -706.19]. Mean differences across VE/VCO2 slope were -6.55 (95 % CI -7.24 to -5.87). Those patients' characteristics and exercise were similar (frequency = 3-5 times/week; duration = 20-50 min/day; intensity = 60-80 % of VO2 peak) on the included studies. Moreover, the risk of bias across all studies was homogeneous (PEDro scale = 7-8 points). However, based on the statistical analysis, the heterogeneity among the studies was still high, which is related to the variable characteristics of the studies. Aerobic exercise may be effective at improving NTproBNP and the VE/VCO2 slope in systolic HF patients, but these effects are limited to a specific HF population meeting specific inclusion criterion in a limited number of studies. Future randomized controlled studies including diastolic and HF overleap with pulmonary diseases are needed to better understand the exact influence of AEX.

Changes in body composition in heart failure patients after a resistance exercise program and branched chain amino acid supplementation

BACKGROUND & AIMS

Heart Failure (HF) is a complex syndrome, which can include the physiological, neural hormonal and metabolic complications known as "Cardiac Cachexia" (CC). In the development of CC there is a release of catabolic cytokines (Tumor Necrosis Factor-α, interleukins 1 and 6) that cause a decrease of fat free mass and fat mass. These changes in body composition might be reversed with a therapeutic combination of resistance exercise and branched chain amino acid supplementation (BCAA).

AIM

Evaluate changes in body composition after a resistance exercise program and BCAA supplementation in patients with HF.

METHODS

In a randomized clinical trial with 3 month of follow-up anthropometric body composition analysis and stress tests were evaluated at the beginning and in the end of the study. Patients were divided into two groups; the experimental group performed the resistance exercise program and received 10 g/day BCAA supplementation, and the control group only performed the resistance exercise program. Both groups were provided with individualized diets and conventional medical treatment.

RESULTS

Changes were found in hip circumference between the groups (p = 0.02), and muscle strength was increased in the experimental group (8%) and the control group (11.4%) with no difference between them. METS and VO2Max also increased in experimental and control groups (16.6% and 50.1% respectively). Regarding changes in symptoms, improvements in fatigue (45.4%), decubitus intolerance (21.8%) and dyspnea (25.4%) were observed in the overall sample.

CONCLUSION

Improvements in physical and functional capacities are attributed to resistance exercise program but not to the BCAA supplementation.

CLINICAL TRIALS IDENTIFIER

NCT02240511.

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.

Reasonable expectations: how much aerobic capacity, muscle strength, and quality of life can improve with exercise training in heart failure

In this article, the literature that describes the magnitude of functional and quality of life gains with a traditional moderate-intensity aerobic and resistance training programs is reviewed, and differences between the impact of exercise training in heart failure with preserved ejection fraction versus heart failure with reduced ejection fraction are discussed.

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.

Exercise and heart failure in the elderly

In this review, we will examine the physiological responses to exercise in elderly populations (age > 65 years) with and without evidence of heart failure. Aging per se in both men and women is associated with a ~40% lower maximum oxygen consumption in sedentary subjects. In trained individuals, this value is 25-32% lower. A smaller SV accounts for nearly 50% of these age-related differences, and the remainder is explained by a lower maximal HR and reduced oxygen extraction. Exercise training is also associated with an increase in the arteriovenous O(2) difference in previously sedentary elderly men and women, which probably contributes to the overall beneficial effect of training in the elderly. However, during vigorous exercise (125 W), the cardiac output in the elderly is dependent upon an age-related increase in end-diastolic volume and stroke volume, which "compensates" partially for the age-related decrease in heart rate. Hence, in elderly individuals, the stroke volume during exercise depends upon diastolic filling. The changes that occur in the heart are also associated with an overall reduction in efferent sympathetic nerve activity. Despite this decline, the metaboreflex initiated by receptors in exercising muscles remains the main determinant of sympathetic activation (to maintain blood pressure) during exercise in the elderly. It is recognized that aging is associated with the development of heart failure, particularly in women in whom its prevalence increases >twofold from age 65-69 (6.6%) to age 85 years (14%). Almost half the people presenting with heart failure appear to have normal left ventricular systolic function, a phenomenon that is more common in women. Exercise training in elderly people with and without heart failure appears to have a beneficial effect in terms of enhancing the quality of life and functional capacity. Mortality benefit in the latter has not been established with certainty.

Eccentric training in chronic heart failure: feasibility and functional effects. Results of a comparative study

OBJECTIVES

To evaluate, in chronic heart failure (CHF) patients, feasibility, safety, compliance and functional improvements of an eccentric (ECC) cycle training protocol personalized by the rate of perceived exertion (RPE; 9-11 Borg Scale), compared to concentric (CON) training at workload corresponding to the first ventilatory threshold.

METHODS

Thirty patients were randomly allocated to ECC or CON training (20 sessions). Compliance was evaluated with RPE, visual analog scale for muscle soreness and monitoring of heart rate (HR). Functional parameters were measured by the distance walked and the VO(2) uptake during the 6-minute walk test (6MWT) before and after training.

RESULTS

Two patients were excluded due to adverse effects in each group. RPE was 9-11 in ECC training while it reached 12-14 in CON training. HR remained stable in ECC group during exercise whereas it increased during CON exercise. 6MWT distance improved in both group (ECC: +53 m; CON: +33 m). 6MWT VO(2) uptake remained stable in ECC group whereas it increased in CON group.

CONCLUSION

ECC training tailored by RPE appears to be an efficient and safe alternative for CHF patients. Indeed, it induces functional improvement similar to conventional CON training with lower demand on the cardiovascular system during exercise.

Exercise training restores cardiac protein quality control in heart failure

Exercise training is a well-known coadjuvant in heart failure treatment; however, the molecular mechanisms underlying its beneficial effects remain elusive. Despite the primary cause, heart failure is often preceded by two distinct phenomena: mitochondria dysfunction and cytosolic protein quality control disruption. The objective of the study was to determine the contribution of exercise training in regulating cardiac mitochondria metabolism and cytosolic protein quality control in a post-myocardial infarction-induced heart failure (MI-HF) animal model. Our data demonstrated that isolated cardiac mitochondria from MI-HF rats displayed decreased oxygen consumption, reduced maximum calcium uptake and elevated H₂O₂ release. These changes were accompanied by exacerbated cardiac oxidative stress and proteasomal insufficiency. Declined proteasomal activity contributes to cardiac protein quality control disruption in our MI-HF model. Using cultured neonatal cardiomyocytes, we showed that either antimycin A or H₂O₂ resulted in inactivation of proteasomal peptidase activity, accumulation of oxidized proteins and cell death, recapitulating our in vivo model. Of interest, eight weeks of exercise training improved cardiac function, peak oxygen uptake and exercise tolerance in MI-HF rats. Moreover, exercise training restored mitochondrial oxygen consumption, increased Ca²⁺-induced permeability transition and reduced H₂O₂ release in MI-HF rats. These changes were followed by reduced oxidative stress and better cardiac protein quality control. Taken together, our findings uncover the potential contribution of mitochondrial dysfunction and cytosolic protein quality control disruption to heart failure and highlight the positive effects of exercise training in re-establishing cardiac mitochondrial physiology and protein quality control, reinforcing the importance of this intervention as a non-pharmacological tool for heart failure therapy.

Training effects on peripheral muscle oxygenation and performance in children with congenital heart diseases

We investigated the effect of training on peripheral muscular performance and oxygenation during exercise and recovery in children with congenital heart diseases (CHD). Eighteen patients with CHD aged 12 to 15 years were randomly assigned into either an individualized 12-week aerobic cycling training group (TG) or a control group (CG). Maximal voluntary contraction (MVC) and endurance at 50% MVC (time to exhaustion, Tlim) of the knee extensors were measured before and after training. During the 50% MVC exercise and recovery, near-infrared spectroscopy (NIRS) was used to assess the fall in muscle oxygenation, i.e., deoxygenation ([Formula: see text]) of the vastus lateralis, the mean rate of decrease in muscle oxygenation, the half time of recovery (T1/2R), and the recovery speed to maximal oxygenation (RS). There was no effect of time on any parameter in the CG. After training, significant improvements were observed in TG for MVC (101.6 ± 14.0 vs. 120.2 ± 19.4 N·m, p < 0.01) and Tlim (66.2 ± 22.6 vs. 86.0 ± 23.0 s, p< 0.01). Increased oxygenation (0.20 ± 0.13 vs. 0.15 ± 0.07 a.u., p < 0.01) and faster mean rate of decrease in muscle oxygenation were also shown after training in TG (1.22 ± 0.45 vs. 1.71 ± 0.78%·s–1, p < 0.001). Moreover, a shorter recovery time was observed in TG after training for T1/2R (27.2 ± 6.1 vs. 20.8 ± 4.2 s, p < 0.01) and RS (63.1 ± 18.4 vs. 50.3 ± 11.4 s, p < 0.01). A significant relationship between the change in [Formula: see text] and both MVC (r = 0.95, p < 0.001) and Tlim (r = 0.90, p < 0.001) in TG was observed. We concluded that exercise training improves peripheral muscular function by enhancing strength and endurance performance in children with CHD. This improvement was associated with increased oxygenation of peripheral muscles and faster recovery.