The role of exercise training in heart failure

Improving effect of physical exercise on heart failure: Reducing oxidative stress-induced inflammation by restoring Ca2+ homeostasis

Heart failure (HF) is associated with the occurrence of mitochondrial dysfunction. ATP produced by mitochondria through the tricarboxylic acid cycle is the main source of energy for the heart. Excessive release of Ca2+ from myocardial sarcoplasmic reticulum (SR) in HF leads to excessive Ca2+ entering mitochondria, which leads to mitochondrial dysfunction and REDOX imbalance. Excessive accumulation of ROS leads to mitochondrial structure damage, which cannot produce and provide energy. In addition, the accumulation of a large number of ROS can activate NF-κB, leading to myocardial inflammation. Energy deficit in the myocardium has long been considered to be the main mechanism connecting mitochondrial dysfunction and systolic failure. However, exercise can improve the Ca2+ imbalance in HF and restore the Ca2+ disorder in mitochondria. Similarly, exercise activates mitochondrial dynamics to improve mitochondrial function and reshape intact mitochondrial structure, rebalance mitochondrial REDOX, reduce excessive release of ROS, and rescue cardiomyocyte energy failure in HF. In this review, we summarize recent evidence that exercise can improve Ca2+ homeostasis in the SR and activate mitochondrial dynamics, improve mitochondrial function, and reduce oxidative stress levels in HF patients, thereby reducing chronic inflammation in HF patients. The improvement of mitochondrial dynamics is beneficial for ameliorating metabolic flow bottlenecks, REDOX imbalance, ROS balance, impaired mitochondrial Ca2+ homeostasis, and inflammation. Interpretation of these findings will lead to new approaches to disease mechanisms and treatment.

Cardiac Rehabilitation and Heart Failure with Reduced Ejection Fraction: Pathophysiology, Benefits, and Precautions

Heart failure (HF) is a highly comorbid condition associated with significant mortality, despite advances in current medical management. Patients who suffer from HF represent a high needs disease care population in whom structured, long-term chronic disease care delivery models, such as cardiac rehabilitation (CR), have been shown to be highly cost effective in reducing hospitalizations and improving quality of life. HF with reduced ejection fraction affects a growing number of Canadians and health care costs secondary to this condition are increasing, with further increases over the next decade to be expected. CR is a guideline-directed medical therapy for patients living with HF with reduced ejection fraction, and with increasing numbers of HF patients across the world, there is a prescient need to revisit the benefits, safety, and the prescription of this intervention for the health care professionals who treat this condition. Certainly, there is a clinical need for HF practitioners to better understand the pathophysiological benefits of CR with respect to exercise training, as well as the prudent precautions required to facilitate the safe delivery of this highly cost-effective patient intervention.

Evaluation of upper extremity functional capacity and activities of daily living in patients with heart failure: A cross-sectional study

BACKGROUND

Considering the limitations in activities of daily living (ADL) and the impact of improvements in patients with heart failure (HF), appropriate assessment of upper extremity functional capacity and ADL is important.

OBJECTIVES

To evaluate upper extremity functional capacity and ADL in patients with HF and compare them with healthy controls.

METHODS

This study included 30 HF patients and healthy controls. Upper extremity functional capacity was assessed with the 6-Minute Pegboard Ring Test (6PBRT), ADL by the Londrina protocol, exercise capacity by 6-Minute Walk Test (6MWT), peripheral muscle strength by hand dynamometer, and dyspnea by Modified Medical Research Council Scale (MMRC). For performance tests, pre-test (resting) and post-test (after performance) values ​​were also measured.

RESULTS

Patients with HF with ejection fraction ≤50 % and controls were similar in terms of age (52.63±6.2 and 50.03±6.5 years, respectively) and gender (25 females for each group) (p > 0.05). Patients showed a statistically significant increase in total test time in the Londrina protocol and fewer rings moved in 6PBRT (p < 0.0001). The post-test dyspnea (p = 0.03) and pre-test arm fatigue (p < 0.0001) were observed to be higher in patients in the Londrina protocol. There was a statistically significant group by time interaction in the patients' pre- and post-test lower heart rate (F= 4.80, p = 0.03), post-test dyspnea (p < 0.0001), and post-test arm fatigue (p = 0.005) were observed to be higher in patients in 6PBRT.

CONCLUSIONS

The evidence showed a decrease in upper extremity functional capacity in patients with HF. Patients required more time to perform their ADLs compared with healthy controls.

Effects of physical training on the metabolic profile of rats exposed to chronic restraint stress

INTRODUCTION

Despite strong evidences supporting the protective role of exercise against stress-induced repercussions, the literature remains inconclusive regarding metabolic aspects. Therefore, this study aimed to evaluate the effect of Physical Training (PT) by swimming on the metabolic parameters of rats subjected to restraint stress.

METHODS

Wistar rats (n = 40) were divided into four groups: Control (C), Trained (T), Stressed (S), and Trained/Stressed (TS). The restraint stress protocol involved confining the animals in PVC pipes for 60 minutes/day for 12 weeks. Concurrently, the swimming PT protocol was performed without additional load in entailed sessions of 60 minutes conducted five days a week for the same duration. The following parameters were analyzed: fitness progression assessed by the physical capacity test, body mass, serum level of glucose, triglyceride, cholesterol and corticosterone, as well as glycemic tolerance test, evaluated after glucose administration (2 g/kg, i.p.).

RESULTS

Trained groups (T and TS) exhibited enhanced physical capacity (169 ± 21 and 162 ± 22% increase, respectively) compared to untrained groups (C: 9 ± 5 and S: 11 ± 13% increase). Corticosterone levels were significantly higher in the S group (335 ± 9 nmoL/L) compared to C (141 ± 3 nmoL/L), T (174 ± 3 nmoL/L) and TS (231 ± 7 nmoL/L), which did not differ from each other. There were no significant changes in serum glucose, cholesterol, and triglyceride levels among the groups. However, the glycemic curve after glucose loading revealed increased glycemia in the S group (area under curve 913 ± 30 AU) but the TS group exhibited values (673 ± 12 AU) similar to the groups C (644 ± 10 AU) and T (649 ± 9 AU).

CONCLUSION

Swimming-based training attenuated stress-induced corticosterone release and prevented glucose intolerance in rats, reinforcing the importance of exercise as a potential strategy to mitigate the pathophysiological effects of stress.

Contribution of reduced skeletal muscle perfusion reserve to exercise intolerance in heart failure with preserved ejection fraction

BACKGROUND

Skeletal muscle (SM)-associated mechanisms of exercise intolerance in HFpEF are insufficiently defined, and inadequate augmentation of SM blood flow during physical effort may be one of the contributors. Therefore, we sought to investigate the association of SM perfusion response to exertion with exercise capacity in this clinical condition.

METHODS

Echocardiography and SM microvascular perfusion by contrast-enhanced ultrasound were performed at rest and immediately post-exercise test in 77 HFpEF patients in NYHA class II and III, and in 25 subjects with normal exercise tolerance (stage B). Exercise reserve of cardiac function and SM perfusion was calculated by subtracting resting value from exercise value.

RESULTS

In addition to decreased cardiac functional reserve, HFpEF patients demonstrated significantly reduced SM perfusion reserve as compared to HF stage B, with the degree of impairment being greater in the subgroup with more profound left ventricular (LV) diastolic abnormalities (E/e' > 15 and TRV > 2.8 m/s). SM perfusion reserve was significantly associated with exercise capacity (beta = 0.33; SE 0.11; p = 0.003), cardiac output reserve (beta = 0.24; SE 0.12; p = 0.039), resting E/e' (beta = -0.33; SE 0.11; p = 0.006), and patient frailty expressed by the PRISMA 7 score (beta = -0.30; SE 0.11; p = 0.008). In multivariable analysis including clinical, demographic and cardiac functional variables, SM perfusion reserve was in addition to patient frailty, sex and LV longitudinal strain reserve among the independent correlates of exercise capacity.

CONCLUSIONS

SM perfusion reserve is impaired in HFpEF, and is associated with reduced exercise capacity independent of clinical, demographic and "central" cardiac factors. This supports the need to consider the SM domain in patient management strategies in HFpEF.

Nrf2 and autonomic dysregulation in chronic heart failure and hypertension

Redox imbalance plays essential role in the pathogenesis of cardiovascular diseases. Chronic heart failure (CHF) and hypertension are associated with central oxidative stress, which is partly mediated by the downregulation of antioxidant enzymes in the central autonomic neurons that regulate sympathetic outflow, resulting in sympathoexcitation. Antioxidant proteins are partially regulated by the transcriptional factor nuclear factor erythroid 2-related factor 2 (Nrf2). Downregulation of Nrf2 is key to disrupting central redox homeostasis and mediating sympathetic nerve activity in the setting of Chronic heart failure and hypertension. Nrf2, in turn, is regulated by various mechanisms, such as extracellular vesicle-enriched microRNAs derived from several cell types, including heart and skeletal muscle. In this review, we discuss the role of Nrf2 in regulating oxidative stress in the brain and its impact on sympathoexcitation in Chronic heart failure and hypertension. Importantly, we also discuss interorgan communication via extracellular vesicle pathways that mediate central redox imbalance through Nrf2 signaling.

Exercise, exerkines, and cardiometabolic health: from individual players to a team sport

Exercise confers numerous salutary effects that extend beyond individual organ systems to provide systemic health benefits. Here, we discuss the role of exercise in cardiovascular health. We summarize major findings from human exercise studies in cardiometabolic disease. We next describe our current understanding of cardiac-specific substrate metabolism that occurs with acute exercise and in response to exercise training. We subsequently focus on exercise-stimulated circulating biochemicals ("exerkines") as a paradigm for understanding the global health circuitry of exercise, and discuss important concepts in this emerging field before highlighting exerkines relevant in cardiovascular health and disease. Finally, this Review identifies gaps that remain in the field of exercise science and opportunities that exist to translate biologic insights into human health improvement.

Obesity in Pediatric Congenital Heart Disease: The Role of Age, Complexity, and Sociodemographics

The prevalence of obesity in children with congenital heart disease (CHD) is greater than 25%, putting these patients at-risk for increased surgical morbidity and mortality. Our goal was to determine the association between CHD complexity, sociodemographic factors, and obesity. Our hypothesis was that among CHD patients, the odds of obesity would be highest in older children with simple CHD, and in all children with a lower socioeconomic status. We conducted a retrospective cohort study, reviewing electronic medical records of children aged 2-17 years from over 50 outpatient pediatric clinics in Houston, TX. Children were classified as simple or moderate/complex CHD, and obesity was defined by BMI ≥ 95th percentile for age and sex. Logistic regression was used to determine the association between sociodemographic factors and CHD complexity with obesity. We identified 648 CHD and 369,776 non-CHD patients. Children with simple CHD had a similar odds of obesity as non-CHD children. Children with CHD had a higher prevalence of obesity if they were older, male, Black, Hispanic, and publicly insured. Children with moderate/complex CHD had lower odds of obesity [OR 0.24 (95% CI 0.07-0.73)], however their predicted probability of obesity approached that of the general population as they aged. Additionally, there was an incremental relationship with poverty and obesity [1.01 (1.01-1.01)]. Awareness of which patients with CHD are at highest risk of obesity may help in targeting interventions to assist at-risk patients maintain a healthy lifestyle.

A brainstem monosynaptic excitatory pathway that drives locomotor activities and sympathetic cardiovascular responses

Exercise including locomotion requires appropriate autonomic cardiovascular adjustments to meet the metabolic demands of contracting muscles, yet the functional brain architecture underlying these adjustments remains unknown. Here, we demonstrate brainstem circuitry that plays an essential role in relaying volitional motor signals, i.e., central command, to drive locomotor activities and sympathetic cardiovascular responses. Mesencephalic locomotor neurons in rats transmit central command-driven excitatory signals onto the rostral ventrolateral medulla at least partially via glutamatergic processes, to activate both somatomotor and sympathetic nervous systems. Optogenetic excitation of this monosynaptic pathway elicits locomotor and cardiovascular responses as seen during running exercise, whereas pathway inhibition suppresses the locomotor activities and blood pressure elevation during voluntary running without affecting basal cardiovascular homeostasis. These results demonstrate an important subcortical pathway that transmits central command signals, providing a key insight into the central circuit mechanism required for the physiological conditioning essential to maximize exercise performance.

Could SGLT2 Inhibitors Improve Exercise Intolerance in Chronic Heart Failure?

Despite the constant improvement of therapeutical options, heart failure (HF) remains associated with high mortality and morbidity. While new developments in guideline-recommended therapies can prolong survival and postpone HF hospitalizations, impaired exercise capacity remains one of the most debilitating symptoms of HF. Exercise intolerance in HF is multifactorial in origin, as the underlying cardiovascular pathology and reactive changes in skeletal muscle composition and metabolism both contribute. Recently, sodium-related glucose transporter 2 (SGLT2) inhibitors were found to improve cardiovascular outcomes significantly. Whilst much effort has been devoted to untangling the mechanisms responsible for these cardiovascular benefits of SGLT2 inhibitors, little is known about the effect of SGLT2 inhibitors on exercise performance in HF. This review provides an overview of the pathophysiological mechanisms that are responsible for exercise intolerance in HF, elaborates on the potential SGLT2-inhibitor-mediated effects on these phenomena, and provides an up-to-date overview of existing studies on the effect of SGLT2 inhibitors on clinical outcome parameters that are relevant to the assessment of exercise capacity. Finally, current gaps in the evidence and potential future perspectives on the effects of SGLT2 inhibitors on exercise intolerance in chronic HF are discussed.

Contribution of Peripheral Chemoreceptors to Exercise Intolerance in Heart Failure

Peripheral chemoreceptors (PChRs), because of their strategic localization at the bifurcation of the common carotid artery and along the aortic arch, play an important protective role against hypoxia. Stimulation of PChRs evokes hyperventilation and hypertension to maintain adequate oxygenation of critical organs. A relationship between increased sensitivity of PChRs (hyperreflexia) and exercise intolerance (ExIn) in patients with heart failure (HF) has been previously reported. Moreover, some studies employing an acute blockade of PChRs (e.g., using oxygen or opioids) demonstrated improvement in exercise capacity, suggesting that hypertonicity is also involved in the development of ExIn in HF. Nonetheless, the precise mechanisms linking dysfunctional PChRs to ExIn remain unclear. From the clinical perspective, there are two main factors limiting exercise capacity in HF patients: subjective perception of dyspnoea and muscle fatigue. Both have many determinants that might be influenced by abnormal signalling from PChRs, including: exertional hyperventilation, oscillatory ventilation, ergoreceptor oversensitivity, and augmented sympathetic tone. The latter results in reduced muscle perfusion and altered muscle structure. In this review, we intend to present the milieu of abnormalities tied to malfunctioning PChRs and discuss their role in the complex relationships leading, ultimately, to ExIn.

Effects of resistance added on aerobic training on autonomic function in cardiac patients

OBJECTIVE

Autonomic imbalance in patients with chronic heart failure (CHF) and cardiovascular diseases (CVD) is characterized by reduced parasympathetic and enhanced sympathetic activity. Aerobic exercise improves autonomic function in patients with CHF and CVD. However, little is known about the effects of resistance training (RT) on cardiac autonomic function. Therefore, we aimed to investigate the effects of RT added on aerobic training on autonomic function in patients with CHF and CVD.

DATA SOURCES

The relevant clinical trials were searched in PubMed, Physiotherapy evidence Database (PEDro, Science Direct and Google Scholar databases using the following keywords, "resistance or strength training", "chronic heart failure", "coronary artery disease", "myocardial infarction", "hypertension", "cardiovascular disease", "heart rate variability (HRV)", "heart rate recovery (HRR)", "muscle sympathetic nerve activity (MSNA)", and "autonomic function".

DATA SYNTHESIS

Twelve articles with 323 subjects were eligible to be evaluated. The outcome measures included HRV, HRR, and MSNA. There were seven studies on CHF, two on CAD, and three studies on hypertension. Meta-analysis of all the studies showed that combined RT and aerobic training decreased MSNA significantly in patients with CHF and CAD (mean difference: -3.796; CI: -6.779 to 0.813; p=0.013; I2 =93.5%). No study evaluated the effects of RT or combined training on HRR.

CONCLUSION

We could not find sufficient data about the effects of RT alone on HRV and HRR, but the results showed that combined RT and aerobic training improved MSNA in patients with CHF and CAD, significantly. Further studies with similar methodological principles on the same patient population are needed.

Movement-based mind-body interventions for cardiac rehabilitation: An updated systematic review of randomized controlled trials

This study aimed to assess evidence for the effect of movement-based mind-body interventions (MMBIs) for cardiac rehabilitation (CR). Six databases were searched from January 1995 to September 2020. All randomized controlled trials (RCTs) evaluated the effect of MMBIs on heart disease (HD) patients' physical and psychological outcomes. Two reviewers independently assessed the quality of all the included studies using the revised Cochrane risk-of-bias tool for RCTs. Sixteen RCTs (5160 participants) published between 1996 and 2020 met all inclusion criteria. In total, these studies investigated the effect of MMBIs for CR. Outcome measures that emerged in these studies included physical and psychological, and/or biochemical parameters to comprehensively evaluate the effects of MMBIs on HD patients. Overall, these studies suggest that MMBIs seem to be an alternative with the optimal CR option.

Exercise-Based Cardiac Rehabilitation Improves Exercise Capacity Regardless of the Response to Cardiac Resynchronization Therapy in Patients With Heart Failure and Reduced Ejection Fraction

BACKGROUND

In patients with chronic heart failure with reduced ejection fraction (HFrEF), cardiac resynchronization therapy (CRT) improves left ventricular ejection fraction (LVEF) and exercise-based cardiac rehabilitation (ECR) enhances exercise capacity. This study examined the relationship between the 2 responses.

METHODS AND RESULTS

Sixty-four consecutive HFrEF patients who participated in a 3-month ECR program after CRT were investigated. Patients were categorized according to a median improvement in peak oxygen uptake (PV̇O2) after ECR of 7% as either good (n=32; mean percentage change in PV̇O2[%∆PV̇O2]=23.2%) or poor (n=32; mean %∆PV̇O2=2.5%) responders. There was no significant difference in baseline characteristics between the good and poor responders, except for PV̇O2(51% vs. 59%, respectively; P=0.01). The proportion of good CRT responders was similar between the good and poor responders (%∆LVEF ≥10%; 53% vs. 47%, respectively; P=NS). Overall, there was no significant correlation between %∆LVEF after CRT and %∆PV̇O2after ECR. Notably, among poor CRT responders (n=32), the prevalence of atrial fibrillation (0% vs. 29%; P<0.03) and baseline PV̇O2(48% vs. 57%; P<0.05) were significantly lower among those with a good (n=15) than poor (n=17) response to ECR.

CONCLUSIONS

In patients with HFrEF, good ECR and CRT responses are unrelated. A good PV̇O2response to ECR can be achieved even in poor CRT responders, particularly in those with a sinus rhythm or low baseline PV̇O2.

Acute Cardiorespiratory Responses to Different Exercise Modalities in Chronic Heart Failure Patients-A Pilot Study

The purpose of this study was to compare the acute cardiorespiratory responses and time spent above different %VO2peak intensities between three "iso-work" protocols: (a) a high intensity interval training protocol (HIIT), (b) a higher intensity continuous protocol (CON70) and (c) a lower intensity continuous protocol (CON50) in patients with chronic heart failure (CHF). Ten male CHF patients (aged 55.1 ± 16.2 years) performed in separate days a single session of a HIIT protocol consisted of 4 sets × 4 min cycling at 80% VO2peak with 3 min of recovery at 50% VO2peak, a CON70 protocol corresponding to 70% VO2peak and a CON50 protocol corresponding to 50% VO2peak. Cardiopulmonary data were collected by an online gas analysis system. The HIIT and CON70 elicited higher cardiorespiratory responses compared to CON50 with no differences between them (p > 0.05). In HIIT and CON70, patients exercised longer at >80% and >90% VO2peak. The completion rate was 100% for the three protocols. Not any adverse events were observed in either protocol. Both HIIT and CON70 elicited a stronger physiological stimulus and required shorter time than CON50. Both HIIT and CON70 also induced comparable hemodynamic responses and ventilatory demand.

Objectively Measured Physical Activity Is Associated with Static Balance in Young Adults

Purpose: Regular physical activity (PA) strengthens muscles and improves balance and coordination of human body. The aim of this study was to examine whether objectively measured physical activity (PA) and sedentary behaviors were related to static balance in young men and women. Design and setting: Cross-sectional community study. Participants: 86 healthy adults (50% women) aged 21.26 ± 2.11 years. Method: PA variables, including moderate-to-vigorous PA (MVPA), light PA (LPA), sedentary time (SED), and sedentary breaks, were measured by accelerometers on wrist (ActiGraph WGT3X-BT). The static balance was tested in the bipedal stance with eyes open or closed. The movement of the center of pressure, including total sway path length (SP), sway velocity (SV), and sway area (SA), was recorded with a three-dimensional force platform (Kistler 9287CA). The associations between PA (MVPA/LPA/SED/sedentary breaks) and static balance (SP/SV/SA) were analyzed using mixed linear regression analyses, with adjustments for condition (eyes open/closed), sex, age, body mass index (BMI), total device wearing time, and PA*condition. Data were analyzed with SPSS 24.0. Results: Better performance was observed in eyes-open condition (p < 0.05). MVPA was negatively associated with SA (p = 0.030), and SED was positively associated with SA after adjustments, respectively (p = 0.0004). No significance was found in the association of light PA, SED, or sedentary breaks with other static balance variables, respectively (p > 0.05). Conclusion: Increasing MVPA and less SED are associated with lower sway area measured by force platform, indicating more PA may related to better static balance in young adults.

Physical Activity in the Treatment and Prevention of Heart Failure: An Update

ABSTRACT

Heart failure (HF) is a complex clinical syndrome hallmarked by an inability to match cardiac output with metabolic demand, resulting in exercise intolerance. HF is increasingly prevalent in an aging population and accounts for substantial burden of health care costs and morbidity. Because many of the central and peripheral mechanisms of HF respond favorably to exercise training, its role in HF treatment is becoming established. The role of habitual physical activity in the primary prevention of HF is less clear; however, available evidence is supportive. This article reviews recently published studies on exercise training and usual physical activity in HF treatment and prevention, discusses potential mechanisms, and suggests areas where further research is needed.

Current concept in the diagnosis, treatment and rehabilitation of patients with congestive heart failure

Heart failure (HF) is a major public health problem with a prevalence of 1%-2% in developed countries. The underlying pathophysiology of HF is complex and as a clinical syndrome is characterized by various symptoms and signs. HF is classified according to left ventricular ejection fraction (LVEF) and falls into three groups: LVEF ≥ 50% - HF with preserved ejection fraction (HFpEF), LVEF < 40% - HF with reduced ejection fraction (HFrEF), LVEF 40%-49% - HF with mid-range ejection fraction. Diagnosing HF is primarily a clinical approach and it is based on anamnesis, physical examination, echocardiogram, radiological findings of the heart and lungs and laboratory tests, including a specific markers of HF - brain natriuretic peptide or N-terminal pro-B-type natriuretic peptide as well as other diagnostic tests in order to elucidate possible etiologies. Updated diagnostic algorithms for HFpEF have been recommended (H2FPEF, HFA-PEFF). New therapeutic options improve clinical outcomes as well as functional status in patients with HFrEF (e.g., sodium-glucose cotransporter-2 - SGLT2 inhibitors) and such progress in treatment of HFrEF patients resulted in new working definition of the term "HF with recovered left ventricular ejection fraction". In line with rapid development of HF treatment, cardiac rehabilitation becomes an increasingly important part of overall approach to patients with chronic HF for it has been proven that exercise training can relieve symptoms, improve exercise capacity and quality of life as well as reduce disability and hospitalization rates. We gave an overview of latest insights in HF diagnosis and treatment with special emphasize on the important role of cardiac rehabilitation in such patients.

Exercise intolerance in volume overload heart failure is associated with low carotid body mediated chemoreflex drive

Mounting an appropriate ventilatory response to exercise is crucial to meeting metabolic demands, and abnormal ventilatory responses may contribute to exercise-intolerance (EX-inT) in heart failure (HF) patients. We sought to determine if abnormal ventilatory chemoreflex control contributes to EX-inT in volume-overload HF rats. Cardiac function, hypercapnic (HCVR) and hypoxic (HVR) ventilatory responses, and exercise tolerance were assessed at the end of a 6 week exercise training program. At the conclusion of the training program, exercise tolerant HF rats (HF + EX-T) exhibited improvements in cardiac systolic function and reductions in HCVR, sympathetic tone, and arrhythmias. In contrast, HF rats that were exercise intolerant (HF + EX-inT) exhibited worse diastolic dysfunction, and showed no improvements in cardiac systolic function, HCVR, sympathetic tone, or arrhythmias at the conclusion of the training program. In addition, HF + EX-inT rats had impaired HVR which was associated with increased arrhythmia susceptibility and mortality during hypoxic challenges (~ 60% survival). Finally, we observed that exercise tolerance in HF rats was related to carotid body (CB) function as CB ablation resulted in impaired exercise capacity in HF + EX-T rats. Our results indicate that: (i) exercise may have detrimental effects on cardiac function in HF-EX-inT, and (ii) loss of CB chemoreflex sensitivity contributes to EX-inT in HF.

An overview of cycling as active transportation and as benefit for health

Active transportation is defined as travelling on foot, by bicycle or other non-motorized means, sometimes in combination with other forms of public transportation, in contrast with the use of motor vehicles. The prevalence of sedentary lifestyle and physical inactivity is a growing epidemic in most developed countries that spread over the last three decades; active transportation may be a promising approach to increase physical activity and reduce the risk of non-communicable diseases improving cardiorespiratory fitness and cardiometabolic health. The health benefits of physical activity in reducing mortality and morbidity have been proved by several publications. Cardiorespiratory fitness can be improved by regular physical activity with an amelioration of insulin sensitivity, blood lipid profile, body composition, inflammation, and blood pressure. Active transportation as a daily physical activity is less expensive compared to motor vehicle use. The advantages are remarkable in terms of contrasting obesity and sedentary lifestyle, decrease motor traffic congestion and mitigate climate change. Massive investments in policies and interventions aimed to increase active transportation are not generally promoted and there are differences in the prevalence of active transportation in the daily routine among different areas. As in the literature several studies as randomized trials or observational studies have been published, with different end-points, in order to investigate if active commuting may be the right answer to improve cardiorespiratory fitness and cardiometabolic health, we aimed to review the available evidences of cycling as an active transportation and to consider its benefits on health.

Physical activity modification in youth with congenital heart disease: a comprehensive narrative review

Congenital heart disease (CHD) affects nearly 1% of births. As survival rates have dramatically improved, the majority of individuals with CHD now live into adulthood. As these patients age, they become prone to a large range of complications, such as chronic heart failure and acquired cardiovascular disease. Promotion of a healthy and active lifestyle from childhood onwards has been suggested as a sustainable and effective strategy to enhance cardiovascular health, improve quality of life and reduce immediate and long-term risk in people with CHD. Well-established physical activity consensus statements for youth with CHD have now been published. In this article, we review how increasing physical activity in youth with CHD may offer immediate and long-term cardiovascular benefits, what is known about physical activity in children with CHD, describe the unique factors that contribute to achieving sufficient and insufficient physical activity levels and summarize the evidence of trials on physical activity promotion in youth with CHD. Furthermore, we discuss some of the challenges that need to be addressed by further research regarding the optimal strategy, timing and format of physical activity intervention programmes in children and adolescents with CHD. IMPACT: Congenital heart disease (CHD) affects nearly 1% of births, with the majority of individuals with CHD now living into adulthood due to improved survival. As CHD patients age, they become prone to a large range of cardiovascular complications. This article discusses how and why increasing physical activity in youth with CHD may offer immediate and long-term cardiovascular benefits, the barriers to achieving sufficient physical activity levels and the evidence from trials on physical activity promotion in youth with CHD. The optimal strategy, timing and format of physical activity intervention programmes in children and adolescents with CHD are discussed.

Hypoxanthine Induces Muscular ATP Depletion and Fatigue via UCP2

Hypoxanthine (Hx), an intermediate metabolite of the purine metabolism pathway which is dramatically increased in blood and skeletal muscle during muscle contraction and metabolism, is characterized as a marker of exercise exhaustion. However, the physiological effects of Hx on skeletal muscle remain unknown. Herein, we demonstrate that chronic treatment with Hx through dietary supplementation resulted in skeletal muscle fatigue and impaired the exercise performance of mice without affecting their growth and skeletal muscle development. Hx increased the uncoupling protein 2 (UCP2) expression in the skeletal muscle, which led to decreased energy substrate storage and enhanced glycolysis. These effects could also be verified in acute treatment with Hx through intraperitoneal injection. In addition, muscular specifically knockout of UCP2 through intra-muscle tissue injection of adenovirus-associated virus reversed the effects of Hx. In conclusion, we identified a novel role of Hx in the skeletal muscular fatigue mediated by UCP2-dependent mitochondrial uncoupling. This finding may shed light on the pathological mechanism of clinical muscle dysfunctions due to abnormal metabolism, such as muscle fatigue and weakness.

Cardiac Rehabilitation for Patients With Heart Failure: JACC Expert Panel

Cardiac rehabilitation is defined as a multidisciplinary program that includes exercise training, cardiac risk factor modification, psychosocial assessment, and outcomes assessment. Exercise training and other components of cardiac rehabilitation (CR) are safe and beneficial and result in significant improvements in quality of life, functional capacity, exercise performance, and heart failure (HF)-related hospitalizations in patients with HF. Despite outcome benefits, cost-effectiveness, and strong practice guideline recommendations, CR remains underused. Clinicians, health care leaders, and payers should prioritize incorporating CR as part of the standard of care for patients with HF.

Designing a Randomized Trial with an Age Simulation Suit-Representing People with Health Impairments

Due to demographic change, there is an increasing demand for professional care services, whereby this demand cannot be met by available caregivers. To enable adequate care by relieving informal and formal care, the independence of people with chronic diseases has to be preserved for as long as possible. Assistance approaches can be used that support promoting physical activity, which is a main predictor of independence. One challenge is to design and test such approaches without affecting the people in focus. In this paper, we propose a design for a randomized trial to enable the use of an age simulation suit to generate reference data of people with health impairments with young and healthy participants. Therefore, we focus on situations of increased physical activity.

Atrial fibrillation in heart failure with reduced ejection fraction: a case report of exercise training

BACKGROUND

Heart failure (HF) and atrial fibrillation (AF) are often concomitant and act in a vicious cycle. Atrial fibrillation is associated with greater functional limitations and increased morbidity and mortality in patients with HF. Moreover, AF associated with HF increases patients' physical inactivity, worsening their clinical condition, and prognosis. Exercise training is safe and has clear benefits in HF. However, these benefits have not been demonstrated when AF is associated with HF.

CASE SUMMARY

We present the case of a 57-year-old man with permanent AF and HF with reduced ejection fraction, who underwent 12 weeks of exercise training that included cardiopulmonary exercise testing, neuromuscular sympathetic activity (NMSA), and muscle blood flow (MBF) before and after training.

DISCUSSION

Exercise training was shown to have a potential benefit in reducing the activity of the sympathetic nerve and increasing muscle blood flow, as well as increasing VO2peak and decreasing the VE/VCO2 slope in a patient with AF associated with HF with reduced ejection fraction. These results may indicate favourable clinical implications in this group of patients.

Heart Failure With Preserved Ejection Fraction: A Comprehensive Review and Update of Diagnosis, Pathophysiology, Treatment, and Perioperative Implications

Almost three-quarters of all heart failure patients who are older than 65 have heart failure with preserved ejection fraction (HFpEF). The proportion and hospitalization rate of patients with HFpEF are increasing steadily relative to patients in whom heart failure occurs as result of reduced ejection fraction. The predominance of the HFpEF phenotype most likely is explained by the prevalence of medical conditions associated with an aging population. A multitude of age-related, medical, and lifestyle risk factors for HFpEF have been identified as potential causes for the sustained low-grade proinflammatory state that accelerates disease progression. Profound left ventricular (LV) systolic and diastolic stiffening, elevated LV filling pressures, reduced arterial compliance, left atrial hypertension, pulmonary venous congestion, and microvascular dysfunction characterize HFpEF, but pulmonary arterial hypertension, right ventricular dilation and dysfunction, and atrial fibrillation also frequently occur. These cardiovascular features make patients with HFpEF exquisitely sensitive to the development of hypotension in response to acute declines in LV preload or afterload that may occur during or after surgery. With the exception of symptom mitigation, lifestyle modifications, and rigorous control of comorbid conditions, few long-term treatment options exist for these unfortunate individuals. Patients with HFpEF present for surgery on a regular basis, and anesthesiologists need to be familiar with this heterogeneous and complex clinical syndrome to provide successful care. In this article, the authors review the diagnosis, pathophysiology, and treatment of HFpEF and also discuss its perioperative implications.

Utility of single-item questions to assess physical inactivity in patients with chronic heart failure

Aim

The purpose of this study was to explore the utility of two single‐item self‐report (SR) questions to assess physical inactivity in patients with heart failure (HF).

Methods and results

This is a cross‐sectional study using data from 106 patients with HF equipped with accelerometers for 1 week each. Two SR items relating to physical activity were also collected. Correlations between accelerometer activity counts and the SR items were analysed. Patients were classified as physically active or inactive on the basis of accelerometer counts, and the SR items were used to try to predict that classification. Finally, patients were classified as having high self‐reported physical activity or low self‐reported physical activity, on the basis of the SR items, and the resulting groups were analysed for differences in actual physical activity. There were significant but weak correlations between the SR items and accelerometer counts: ρ = 0.24, P = 0.016 for SR1 and ρ = 0.21, P = 0.033 for SR2. Using SR items to predict whether a patient was physically active or inactive produced an area under the curve of 0.62 for SR1, with a specificity of 92% and a sensitivity of 30%. When dividing patients into groups on the basis of SR1, there was a significant difference of 1583 steps per day, or 49% more steps in the high self‐reported physical activity group (P < 0.001).

Conclusions

There might be utility in the single SR question for high‐specificity screening of large populations to identify physically inactive patients in order to assign therapeutic interventions efficiently where resources are limited.

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.

Association between physical activity, cardiorespiratory fitness, and body composition with menopausal symptoms in early postmenopausal women

OBJECTIVE

The aim of this study was to investigate the relationship between daily physical activity (daily activities, exercise, and sitting time), cardiorespiratory fitness (CRF), and body composition (body mass index [BMI], waist to hip ratio [WHR)] with menopausal symptoms and to determine the strongest predictor(s) of menopausal symptoms.

METHODS

The Menopause Rating Scale questionnaire was used to examine somatic, psychological, urogenital, and total symptoms of menopause. The energy expenditure of daily physical activity, exercise, and sitting time was measured by the International Physical Activity Questionnaire, and CRF was measured by estimating the maximal oxygen intake (VO2max) through the Rockport test. Statistical methods of the Pearson correlation coefficient and hierarchical multiple linear regression were used for data analysis.

RESULTS

Fifty-six women, aged 50 to 65 years, voluntarily participated in the study. Exercise energy expenditure was inversely correlated with total (r = -0.403, P = 0.002), somatic (r = -0.293, P = 0.023), and urogenital (r = -0.343, P = 0.009) symptoms of menopause. VO2max was inversely correlated with urogenital symptoms of menopause (r = -0.414, P = 0.002). WHR was positively correlated with somatic symptoms of menopause (r = 0.286, P = 0.032); sitting was correlated with total (r = 0.40, P = 0.002), somatic (r = 0.325, P = 0.015), and psychological (r = 0.274, P = 0.015) symptoms of menopause. Among the study variables, sitting (β=0.365, P = 0.004) and VO2max (β=-0.286, P = 0.030) were the most important predictors of total symptoms of menopause; sitting was the predictor of somatic symptoms (β=0.265, P = 0.045), and VO2max was the predictor of urogenital symptoms of menopause (β=-0.332, P = 0.014). The inclusion of age, BMI, WHR, and duration of menopause as confounding variables in regression analysis did not change the findings related to the predictions of menopausal symptoms.

CONCLUSION

Reducing sitting time, improving VO2max, decreasing WHR, and exercise can be recommended by priority to alleviate menopausal symptoms. Considering the small number of participants in this investigation, future studies are, however, recommended.

Impact of a Supervised Twelve-Week Combined Physical Training Program in Heart Failure Patients: A Randomized Trial

Purpose

The aim of this study was to compare the effects of supervised combined physical training and unsupervised physician-prescribed regular exercise on the functional capacity and quality of life of heart failure patients.

Methods

This is a longitudinal prospective study composed of 28 consecutive heart failure with reduced ejection fraction patients randomly divided into two age- and gender-matched groups: trained group (n = 17) and nontrained group (n = 11). All patients were submitted to clinical evaluation, transthoracic echocardiography, the Cooper walk test, and a Quality of Life questionnaire before and after a 12-week study protocol. Categorical variables were expressed as proportions and compared with the chi-square test. Two-way ANOVA was performed to compare the continuous variables considering the cofactor groups and time of intervention, and Pearson correlation tests were conducted for the associations in the same group.

Results

No significant differences between groups were found at baseline. At the end of the protocol, there were improvements in the functional capacity and ejection fraction of the trained group in relation to the nontrained group (p < 0.05). There was time and group interaction for improvement in the quality of life in the trained group.

Conclusions

In patients with heart failure with reduced ejection fraction, supervised combined physical training improved exercise tolerance and quality of life compared with the unsupervised regular exercise prescribed in routine medical consultations. Left ventricular systolic function was improved with supervised physical training.

Exercise training in patients with a left ventricular assist device (Ex-VAD): rationale and design of a multicentre, prospective, assessor-blinded, randomized, controlled trial

AIMS

Left ventricular assist device (LVAD) therapy is a promising option for patients with advanced heart failure (HF), refractory to guideline-mandated medical treatment either as a bridge to heart transplantation or as lifelong therapy. Functional capacity improves after LVAD implantation but remains reduced in patients with long-term LVAD therapy. Exercise training (ET) improves functional capacity and quality of life (QoL) in HF and may provide incremental benefits in patients supported with LVAD therapy.

METHODS

The primary objective of Ex-VAD is to investigate whether a 12-week supervised ET can improve peak oxygen uptake (peakVO2 ) measured by cardiopulmonary exercise testing (CPET) on an ergometer. The study is powered to demonstrate a group difference of 3 mL/min/kg in peakVO2 at week 12, with a power of 0.9 and a standard deviation of 5 mL/min/kg. After baseline assessments to determine whether ET is safe, 66 patients at six trial sites with advanced HF and LVAD therapy will be randomized 2:1 to supervised ET or to the control arm of usual care alone. Patients randomized to ET will perform supervised aerobic endurance and resistance ET (three times/week) for 12 weeks. At baseline and during follow-up, anthropometry, CPET, echocardiography (at rest and exercise), and QoL evaluation will be performed. Blood samples will be collected to examine cardiac-specific relevant biomarkers. Overall physical activity, training sessions, and adherence will be monitored and documented throughout the study using accelerometers and patient diaries.

CONCLUSIONS

The Ex-VAD trial will assess the effects of a supervised ET programme on peakVO2 and QoL in patients with LVAD. As LVAD therapy moves from crisis support to ambulatory functional enhancement, this trial will provide a rationale to improve functional capacity and, in perspective, cardiovascular outcomes in LVAD-supported patients with advanced HF.

Prognostic Role of Left Ventricular Dysfunction in Patients With Coronary Artery Disease After an Ambulatory Cardiac Rehabilitation Program

The relationship between left ventricular ejection fraction (LVEF) and outcomes after cardiac rehabilitation (CR) is not well established; therefore we assessed the prognostic role of LVEF at the end of ambulatory CR program in patients (pts) who received coronary revascularization. LVEF was evaluated at hospital discharge and re-assessed at the end of CR in all ST-elevation myocardial infarction and coronary artery bypass graft pts, while in pts with non-ST-elevation MI or elective percutaneous coronary intervention the echocardiography was repeated if they had an impaired LVEF at discharge. New hospitalizations for cardiovascular causes at 1-year, and cardiovascular mortality during long-term follow-up were analyzed. We enrolled in CR 3078 pts, 86% showed LVEF ≥40% and 9% LVEF <40%. Of those with a discharge LVEF <40%, 56% improved LVEF (LVEF ≥40%) after CR. At 1-year, heart failure was the main cause of new hospitalizations in LVEF <40% group compared with LVEF ≥40% group (5% vs 0.4%, p <0.01). During a mean follow up of 48 ± 25 months, cardiovascular death occurred in 9% of pts with LVEF <40% and in 2% with LVEF ≥40% (p = 0.014). At Cox multivariate analysis, LVEF <40% at the end of CR and age were independent predictors of hospitalization and mortality for cardiovascular causes, while coronary artery bypass graft was a protective factor. In conclusion, during CR the improvement of LVEF occurs in a relevant proportion of patients, the re-assessment of LVEF at the end of the CR is helpful for risk stratification because left ventricle dysfunction at the end of CR is associated with worse cardiovascular outcomes.

Impact of in-hospital cardiac rehabilitation on mortality and readmissions in heart failure: A population study in Lombardy, Italy, from 2005 to 2012

Aims

The 2016 European guidelines for the diagnosis and treatment of heart failure classified cardiac rehabilitation as a mandatory class I intervention. We aimed to analyse in heart failure patients the impact of an in-hospital cardiac rehabilitation programme on all-cause mortality and readmissions.

Methods

From the Lombardy healthcare administrative database, we analysed in patients with incident heart failure, from 2005 to 2012, the number of all hospitalisations, cardiac rehabilitation admissions, post-discharge deaths, outpatient drug prescriptions and visits. We divided patients into hospitalised for heart failure in acute care only (group A) versus patients with one or more admission to cardiac rehabilitation for an in-hospital cardiac rehabilitation programme (group B).

Results

Of 140,552 incident cases, 100,843 (71%) were in group A and 39,709 (29%) in group B. Patients in group B had 3.26 ± 1.78 admissions to acute care before referral to an in-hospital cardiac rehabilitation programme. Male gender, age in women and comorbidities (more than two) were higher in group B ( P < 0.0001). Patients in group B had a higher number of interventional procedures ( P < 0.0001), drug prescription and outpatient visit rate ( P < 0.0001). Total mortality was 30% in group A versus 29% in group B. At Cox and logistic regression analyses, after adjustment for covariates, group B had a significantly lower risk of mortality (hazard ratio 0.5768, 95% confidence interval 0.5650–0.5888, P < 0.0001) and readmissions (0.7997, 0.7758–0.8244, P < 0.0001) than group A.

Conclusion

This study showed in a large population of heart failure patients that in-hospital cardiac rehabilitation is associated with a reduction of all-cause mortality and rehospitalisations in heart failure. Given its potential significant benefit, referral of heart failure patients to an in-hospital cardiac rehabilitation programme should be promoted.

Efficacy of Cardiac Rehabilitation in Heart Failure Patients With Low Body Mass Index

BACKGROUND

Low body mass index (BMI) is a relevant prognostic factor for heart failure (HF), but HF patients with low BMI are reported to be at risk of not receiving optimal drug treatment. We sought to evaluate the efficacy of cardiac rehabilitation (CR) in patients with low vs. normal BMI.

METHODS AND RESULTS

We studied 152 consecutive patients (low BMI, n=32; normal BMI, n=119) who participated in a 3-month CR program. Low BMI was defined as <18.5 kg/m2and normal BMI, as 18.5≤BMI<25 kg/m2. All patients underwent cardiopulmonary exercise testing and muscle strength testing at the beginning and end of the 3-month CR program. After CR, a significantly greater proportion of HF patients with low BMI had a positive change in peak V̇O2than in the normal BMI group (91% vs. 70%; P=0.010). Average percent change in peak V̇O2was significantly greater in patients with low vs. normal BMI (17.1±2.8% vs. 7.8±1.5%; P<0.001). In addition, on multivariable logistic regression, low BMI was an independent predictor of a positive change in peak V̇O2after CR (OR, 3.97; 95% CI: 1.10-14.31; P=0.035).

CONCLUSIONS

CR has a greater effect in patients with low than normal BMI, and low BMI is an independent predictor of a positive change in peak V̇O2. Thus, CR should be strongly recommended for HF patients with low BMI.

Sedentary lifestyle associated with mortality in rural patients with heart failure

BACKGROUND

The incidence of mortality five years after the onset of symptomatic heart failure is about 50%. Lifestyle behaviors differ substantially and likely lead to prognostic differences.

AIMS

We sought to determine the factors associated with all-cause mortality in patients with heart failure, particularly the impact of a sedentary lifestyle on mortality.

METHODS

This is a secondary analysis of a randomized controlled trial (REMOTE-HF) to improve self-care through education and counseling ( N=602). We conducted an unadjusted Cox proportional hazards regression analysis with sedentary lifestyle as a predictor of mortality, then added depressive symptoms as a confounder. A Kaplan-Meier survival analysis assessed time to event comparing sedentary lifestyle. Cox models included variables of clinical relevance as well as all significant variables from baseline characteristics associated with all-cause mortality.

RESULTS

The mean ± SD age was 66 ± 12.4 years, 41% were women, and 90% were of white race. There were 125 all-cause deaths over 24 months. Sedentary lifestyle was associated with a 75% increase in the expected hazard of all-cause mortality (hazards ratio 1.75; p = 0.003; 95% CI 1.21-2.54) after adjusting for moderate to severe depressive symptoms. Two Cox models showed an 89 and 95% increase, respectively, in all-cause mortality in sedentary participants holding all other variables constant.

CONCLUSIONS

Sedentary lifestyle is strongly associated with all-cause mortality, independent of having moderate to severe depressive symptoms. Clinicians and researchers have an important role in promoting sustained and safe physical activity to improve survival. Other important modifiable targets to improve survival include depressive symptoms, low literacy, and low body mass index. Clinical Trial Registration- URL: https://www.clinicaltrials.gov . Unique Identifier: NCT00415545.

Exercise promotes a cardioprotective gene program in resident cardiac fibroblasts

Exercise and heart disease both induce cardiac remodeling, but only disease causes fibrosis and compromises heart function. The cardioprotective benefits of exercise have been attributed to changes in cardiomyocyte physiology, but the impact of exercise on cardiac fibroblasts (CFs) is unknown. Here, RNA-sequencing reveals rapid divergence of CF transcriptional programs during exercise and disease. Among the differentially expressed programs, NRF2-dependent antioxidant genes - including metallothioneins (Mt1 and Mt2) - are induced in CFs during exercise and suppressed by TGF-β/p38 signaling in disease. In vivo, mice lacking Mt1/2 exhibit signs of cardiac dysfunction in exercise, including cardiac fibrosis, vascular rarefaction, and functional decline. Mechanistically, exogenous MTs derived from fibroblasts are taken up by cultured cardiomyocytes, reducing oxidative damage-dependent cell death. Importantly, suppression of MT expression is conserved in human heart failure. Taken together, this study defines the acute transcriptional response of CFs to exercise and disease and reveals a cardioprotective mechanism that is lost in disease.

Humoral Immunity in Heart Failure

Cardiovascular Disease (CVD) is a class of diseases that involve disorders of heart and blood vessels, including hypertension, coronary heart disease, cerebrovascular disease, peripheral vascular disease, which finally lead to Heart Failure (HF). There are several treatments available all over the world, but still, CVD and heart failure became the number one problem causing death every year worldwide. Both experimental and clinical studies have shown a role for inflammation in the pathogenesis of heart failure. This seems related to an imbalance between pro-inflammatory and anti-inflammatory cytokines. Cardiac inflammation is a major pathophysiological mechanism operating in the failing heart, regardless of HF aetiology. Disturbances of the cellular and humoral immune system are frequently observed in heart failure. This review describes how B-cells play a specific role in the heart failure states. There is an urgent need to identify novel therapeutic targets and develop advanced therapeutic strategies to combat the syndrome of HF. Understanding and describing the elements of the humoral immunity function are essential and may suggest potential new treatment strategies.

Absence of Fitness Improvement Is Associated with Outcomes in Heart Failure Patients

PURPOSE

This study aimed to examine the clinical effect of cardiorespiratory fitness (CRF) and improvements in CRF after cardiac rehabilitation (CR) in heart failure (HF) patients for their risk for all-cause mortality and unplanned hospitalization and to investigate possible factors associated with the absence of improvement in CRF after rehabilitation.

METHODS

We included 155 HF patients receiving CR between October 2009 and January 2015. Patients performed an incremental bicycle test to assess CRF through peak oxygen uptake (V˙O2-peak) before and after CR-based supervised exercise training. Patients were classified as responders or nonresponders on the basis of pre-to-post CR changes in V˙O2-peak (≥6% and <6%, respectively). Cox proportional hazards models evaluated all-cause mortality and unplanned hospitalization during 5 yr of follow-up. Patient characteristics, HF features, and comorbidities were used to predict changes in V˙O2-peak using logistic regression analysis.

RESULTS

Seventy HF patients (45%) were classified as responder. Nonresponders had a significantly higher risk for all-cause mortality or hospitalization (hazard ratio, 2.15; 95% confidence interval (CI), 1.17-3.94) compared with responders. This was even higher in nonresponders with low CRF at baseline (hazard ratio, 4.88; 95% CI, 1.71-13.93). Factors associated with nonresponse to CR were age (odds ratio (OR), 1.07/yr; 95% CI, 1.03-1.11), baseline V˙O2-peak (OR, 1.16 mL·min·kg; 95% CI, 1.06-1.26), and adherence to CR (OR, 0.98/percentage; 95% CI, 0.96-0.998).

CONCLUSIONS

Independent from baseline CRF, the inability to improve V˙O2-peak by CR doubled the risk for death or unplanned hospitalization. The combination of lower baseline CRF and nonresponse was associated with even poorer clinical outcomes. Especially older HF patients with higher baseline V˙O2-peak and lower adherence have a higher probability of becoming a nonresponder.

Exercise Training Has Contrasting Effects in Myocardial Infarction and Pressure Overload Due to Divergent Endothelial Nitric Oxide Synthase Regulation

The beneficial effects of exercise training (EX) on cardiac pathology are well recognized. Previously, we found that the effects of EX on cardiac dysfunction in mice critically depend on the underlying etiology. EX exerted beneficial effects after myocardial infarction (MI); however, cardiac pathology following pressure overload produced by transverse aortic constriction (TAC) was aggravated by EX. In the presented study, we investigated whether the contrasting effects of EX on cardiac dysfunction can be explained by an etiology-specific response of endothelial nitric oxide (NO) synthase (eNOS) to EX, which divergently affects the balance between nitric oxide and superoxide. For this purpose, mice were exposed to eight weeks of voluntary wheel running or sedentary housing (SED), immediately after sham, MI, or TAC surgery. Left ventricular (LV) function was assessed using echocardiography and hemodynamic measurements. EX ameliorated LV dysfunction and remodeling after MI, but not following TAC, in which EX even aggravated fibrosis. Strikingly, EX attenuated superoxide levels after MI, but exacerbated NOS-dependent superoxide levels following TAC. Similarly, elevated eNOS S-glutathionylation and eNOS monomerization, which were observed in both MI and TAC, were corrected by EX in MI, but aggravated by EX after TAC. Additionally, EX reduced antioxidant activity in TAC, while it was maintained following EX in MI. In conclusion, the present study shows that EX mitigates cardiac dysfunction after MI, likely by attenuating eNOS uncoupling-mediated oxidative stress, whereas EX tends to aggravate cardiac dysfunction following TAC, likely due to exacerbating eNOS-mediated oxidative stress.

Angiotensin II, Oxidative Stress, and Sympathetic Nervous System Hyperactivity in Heart Failure

In congestive heart failure (CHF), sympathetic nervous system is hyperactive. This article reviews current understandings about central and peripheral neural mechanisms underlying sympathetic hyperactivation in this pathological condition. During the development of CHF, renin-angiotensin system (RAS) activities and angiotensin II-mediated oxidative stress become enhanced. Here, on the basis of findings obtained from animal studies, it is examined how RAS overactivation and oxidative stress in central and peripheral nervous systems of CHF mediate sympathetic hyperactivation. Mechanisms by which exercise training in CHF ameliorates RAS overactivation, oxidative stress and sympathetic hyperactivation are also investigated.

Osteopathic manual therapy in heart failure patients: A randomized clinical trial

BACKGROUND

Heart Failure (HF) patients usually present with increased arterial resistance and reduced blood pressure (BP) leading to an impaired functional capacity. Osteopathic Manual Therapy (OMT) focused on myofascial release techniques (MRT) and in the balancing of diaphragmatic tensions, has been shown to improve blood flow in individuals using the resistive index (RI). However, its effects in HF patients have not been examined.

PURPOSE

To evaluate the acute response of selected osteopathic techniques on RI, heart rate (HR), and BP in patients with HF.

METHODS

Randomized-controlled clinical trial of HF patients assigned to MRT (six different techniques with three aimed at the pelvis, two at the thorax, and one at the neck for 15 min) or Control group (subjects in supine position for 15 min without intervention). The RI of the femoral, brachial and carotid arteries was measured via doppler ultrasound while HR and BP were measured via sphygmomanometry before and after a single MRT or control intervention.

RESULTS

Twenty-two HF patients equally distributed (50% male, mean age 53 years; range 32-69 years) (ejection fraction = 35.6%, VO_2peak: 12.9 mL/kg^-1 min^-1) were evaluated. We found no intra or inter group differences in RI of the carotid (Δ_MRT: 0.07% vs Δ _Control:11.8%), brachial (Δ_MRT:0.17% vs Δ_Control: 2.9%), or femoral arteries (Δ_MRT:1.65% vs Δ_Control: 0.97%) (P > 0.05) and no difference in HR or BP (Δ_MRT:0.6% vs Δ_Control: 3%), (P > 0.05).

CONCLUSION

A single MRT session did not significantly change the RI, HR, or BP of HF patients.

Combinatorial therapy of exercise-preconditioning and nanocurcumin formulation supplementation improves cardiac adaptation under hypobaric hypoxia

BACKGROUND

Chronic hypobaric hypoxia (cHH) mediated cardiac insufficiencies are associated with pathological damage. Sustained redox stress and work load are major causative agents of cardiac insufficiencies under cHH. Despite the advancements made in pharmacological (anti-oxidants, vasodilators) and non-pharmacological therapeutics (acclimatization strategies and schedules), only partial success has been achieved in improving cardiac acclimatization to cHH. This necessitates the need for potent combinatorial therapies to improve cardiac acclimatization at high altitudes. We hypothesize that a combinatorial therapy comprising preconditioning to mild aerobic treadmill exercise and supplementation with nanocurcumin formulation (NCF) consisting of nanocurcumin (NC) and pyrroloquinoline quinone (PQQ) might improve cardiac adaptation at high altitudes.

METHODS

Adult Sprague-Dawley rats pre-conditioned to treadmill exercise and supplemented with NCF were exposed to cHH (7620 m altitude corresponding to pO2~8% at 28±2°C, relative humidity 55%±1%) for 3 weeks. The rat hearts were analyzed for changes in markers of oxidative stress (free radical leakage, lipid peroxidation, manganese-superoxide dismutase [MnSOD] activity), cardiac injury (circulating cardiac troponin I [TnI] and T [cTnT], myocardial creatine kinase [CK-MB]), metabolic damage (lactate dehydrogenase [LDH] and acetyl-coenzyme A levels, lactate and pyruvate levels) and bio-energetic insufficiency (ATP, p-AMPKα).

RESULTS

Significant modulations (p≤0.05) in cardiac redox status, metabolic damage, cardiac injury and bio-energetics were observed in rats receiving both NCF supplementation and treadmill exercise-preconditioning compared with rats receiving only one of the treatments.

CONCLUSIONS

The combinatorial therapeutic strategy showed a tremendous improvement in cardiac acclimatization to cHH compared to either exercise-preconditioning or NCF supplementation alone which was evident from the effective modulation in redox, metabolic, contractile and bio-energetic homeostasis.