Effects of exercise training on left ventricular remodelling in heart failure patients: an updated meta-analysis of randomised controlled trials

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.

Comparing the Effect of Moderate-Intensity Versus High-Intensity Interval Training Exercise on Global Longitudinal Strain (GLS) in Cardiovascular Patients: Systematic Review and Meta-Analysis

Left ventricular global longitudinal strain (LVGLS) is a highly sensitive echocardiographic biomarker that detects signs of myocardial dysfunction. It has been proven that exercise-based cardiac rehabilitation (CR) improves LV-GLS but whether high-intensity interval training (HIIT) is more efficient than moderate-intensity interval training (MIIT) to improve LV-GLS as cardiac deformation index in cardiovascular patients is debatable. In the current systematic review and meta-analysis, different digital databases including PubMed, Scopus, Web of Science (ISI), and Google Scholar were searched systematically with no time restriction to answer the abovementioned question. Studies were included that reported GLS as the outcome in CVD subjects before and after enrolling in HIIT and/or MITT. A random effects model was used for meta-analysis. Eleven sets of results from nine articles-two of which had two sets of results-were included. The result of the sensitivity test to check the publication bias was not significant either for MIIT (p=0.211) or for HIIT (p=0.238). Our findings showed that GLS was improved significantly after both MIIT (-1.72. [-2.68, -0.77]) and HIIT (-1.86 [-3.01, -0.71]) in CVD patients; however, the effect of HIIT was greater than MIIT. Subgroup analysis results showed that baseline disease and duration of exercises do not influence the effect of training on GLS. More studies are needed to confirm the conclusion.

Effect of Exercise-Based Cardiac Rehabilitation on Patients With Chronic Heart Failure After Transcatheter Aortic Valve Replacement: A Randomized Controlled Trial

PURPOSE

The objective of this study was to assess the effect of exercise-based cardiac rehabilitation (CR) with individualized exercise prescription in patients with chronic heart failure (HF) undergoing transcatheter aortic valve replacement (TAVR) in a randomized controlled trial.

METHODS

A total of 60 patients with chronic HF who received TAVR treatment were randomly divided into the control group (n = 30) and exercise training (ET) group (n = 30). The control group was treated with conventional rehabilitation, and the ET group was given personalized exercise-based CR based on a cardiopulmonary exercise test (CPX). The CPX parameters, echocardiography, 6-minute walk test distance, and quality of life were evaluated in the two groups.

RESULTS

All patients who completed symptom-restricted CPX showed no complications. After the 12-week rehabilitation period, the levels of anaerobic threshold, peak oxygen uptake, peak oxygen pulse, peak power, left ventricular ejection fraction, and 6-minute walk test distance in the ET group were significantly higher than those in the control group ( P  < .05). Scores on the Minnesota Life with Heart Failure Questionnaire in the ET group were lower than those in the control group ( P < .05).

CONCLUSION

Exercise-based CR significantly improves cardiopulmonary function, exercise tolerance, and quality of life in patients with chronic HF who undergo TAVR.

Exploring the Molecular Adaptations, Benefits, and Future Direction of Exercise Training: Updated Insights into Cardiovascular Health

This review emphasizes the globally accepted physical activity guidelines and explores the various molecular adaptations that occur with continuous exercise. It is essential to highlight the critical roles of cardiorespiratory fitness, muscular strength, and muscle mass in reducing mortality and enhancing quality of life. It has been shown in various studies that there are certainly substantial reductions in cardiovascular and all-cause mortality among individuals with high cardiorespiratory fitness levels. Resistance training is also examined, which, likewise, reveals significant mortality benefits, even with minimal weekly engagement. When delving into the molecular mechanisms, it is apparent that exercise training favorably influences certain cardiovascular conditions, mostly owing to its effect on enhanced lipid metabolism, improvement in glucose regulation, ability to modulate inflammation and oxidative processes, and induction of other cardioprotective effects like improved sympathetic tone and left ventricular remodeling. Cardiovascular diseases and malignancy also share the same risk factors, which explains why exercise can also mitigate the risk of developing many types of cancers. But despite these advancements in research, cardiovascular diseases continue to be prevalent, which may suggest the need to devise other means of promoting physical activity involvement. These approaches may include a greater emphasis on the societal benefits of increased exercise adherence, facilitated by community involvement and technological advancements in fitness tracking devices. We conclude that the future directions for exercise research should emphasize the need for personalized or tailored exercise programs to make it more engaging, accessible, and inclusive for a diverse set of people.

Comparative effect of different physical exercise training on exercise capacity and cardiac function in heart failure with preserved ejection fraction: a network meta-analysis-ExIC-FEp Study

AIMS

This network meta-analysis aimed to compare the effect of different types of physical exercise [endurance training, endurance/resistance training, and high-intensity interval training (HIIT)] on exercise capacity and cardiac function parameters in patients with heart failure with preserved ejection fraction.

METHODS AND RESULTS

A systematic search of the MEDLINE (via PubMed), Scopus, and Web of Science databases was conducted to identify experimental studies addressing the effect of different physical exercise training programmes on exercise capacity and cardiac function in heart failure with preserved ejection fraction. Comparative evaluation of the effect of exercise training type was performed by conducting a standard pairwise meta-analysis and a network meta-analysis for direct and indirect comparisons between exercise training types and controls/non-interventions. Eleven studies were included in the analysis showing that endurance training improves the main exercise capacity parameters (VO2peak, workload, exercise time, peak heart rate, VO2, and 6 min walk distance). Additionally, endurance/resistance training showed a significant effect on VO2peak, workload, early mitral annulus velocity, and early mitral/mitral annulus velocity ratio. Finally, HIIT showed a significant effect on VO2peak, VO2, and the early mitral/mitral annulus velocity ratio.

CONCLUSION

Our findings support the effect of three different types of physical exercise on exercise capacity, mainly VO2peak. Additionally, endurance/resistance training and HIIT could reverse left ventricular remodelling in patients with heart failure with preserved ejection fraction.

REGISTRATION

PROSPERO: CRD42021276111.

Different exercise training intensities prevent type 2 diabetes mellitus-induced myocardial injury in male mice

Type 2 diabetes mellitus (T2DM) usually develop myocardial injury and that exercise may have a positive effect on cardiac function. However, the effect of exercise intensity on cardiac function has not yet been fully examined. This study aimed to explore different exercise intensities on T2DM-induced myocardial injury. 18-week-old male mice were randomly divided into four groups: a control group, the T2DM, T2DM + medium-intensity continuous training (T2DM + MICT), and T2DM + high-intensity interval training (T2DM + HIIT) groups. In the experimental group, mice were given high-fat foods and streptozotocin for six weeks and then divided into two exercise training groups, in which mice were subjected to exercise five days per week for 24 consecutive weeks. Finally, metabolic characteristics, cardiac function, myocardial remodeling, myocardial fibrosis, oxidative stress, and apoptosis were analyzed. HIIT treatment improved cardiac function and improved myocardial injury. In conclusion, HIIT may be an effective means to guard against T2DM-induced myocardial injury.

Regression of cardiac hypertrophy in health and disease: mechanisms and therapeutic potential

Left ventricular hypertrophy is a leading risk factor for cardiovascular morbidity and mortality. Although reverse ventricular remodelling was long thought to be irreversible, evidence from the past three decades indicates that this process is possible with many existing heart disease therapies. The regression of pathological hypertrophy is associated with improved cardiac function, quality of life and long-term health outcomes. However, less than 50% of patients respond favourably to most therapies, and the reversibility of remodelling is influenced by many factors, including age, sex, BMI and disease aetiology. Cardiac hypertrophy also occurs in physiological settings, including pregnancy and exercise, although in these cases, hypertrophy is associated with normal or improved ventricular function and is completely reversible postpartum or with cessation of training. Studies over the past decade have identified the molecular features of hypertrophy regression in health and disease settings, which include modulation of protein synthesis, microRNAs, metabolism and protein degradation pathways. In this Review, we summarize the evidence for hypertrophy regression in patients with current first-line pharmacological and surgical interventions. We further discuss the molecular features of reverse remodelling identified in cell and animal models, highlighting remaining knowledge gaps and the essential questions for future investigation towards the goal of designing specific therapies to promote regression of pathological hypertrophy.

The Role of Exercise-based Cardiac Rehabilitation in Heart Failure

Exercise-based cardiac rehabilitation (EBCR) is a treatment modality for patients with heart failure (HF) that has withstood the test of time. It has continued to show benefits even in the current era of pharmacotherapeutics for HF. Participation in a multidisciplinary comprehensive EBCR programme reduces mortality and morbidity, has a multitude of physiological benefits, and improves cardiovascular risk factor control and quality of life. Despite this, historical barriers to enrolment and uptake remain. Strategies to overcome these, as well as alternative delivery methods of EBCR in HF patients, are emerging and include telerehabilitation, focus on special groups and emphasis on behavioural change. This review provides oversight on the modalities of exercise training in HF as well as their benefits and gives an overview of barriers to the utilisation of EBCR along with future progress in the field.

The effect of exercise training and physiotherapy on left and right heart function in heart failure with preserved ejection fraction: a systematic literature review

The impact of exercise training and physiotherapy on heart function and pulmonary circulation parameters in heart failure with preserved ejection fraction (HFpEF) patients is uncertain. Hence, we performed a systematic review of published trials studying physical training in HFpEF population, with a focus on exercise and physiotherapy effect on left ventricular (LV), right ventricular (RV) morphological, functional, and pulmonary circulation parameters. We searched Cochrane Library and MEDLINE/PubMed for trials that evaluated the effect of exercise training and/or physiotherapy in adult HFpEF patients (defined as LVEF ≥ 45%), including publications until March 2021. Our systematic review identified eighteen articles (n = 418 trained subjects, 4 to 52 weeks of training) and covered heterogeneous trials with various populations, designs, methodologies, and interventions. Five of twelve trials revealed a significant reduction of mitral E/e' ratio after the training (- 1.2 to - 4.9). Seven studies examined left atrial volume index; three of them showed its decrease (- 3.7 to - 8 ml/m2). Findings were inconsistent regarding improvement of cardiac output, E/A ratio, and E wave DecT and uncertain for RV function and pulmonary hypertension parameters. For now, no reliable evidence about rehabilitation effect on HFpEF cardiac mechanisms is available. There are some hypotheses generating findings on potential positive effects to parameters of LV filling pressure (E/e'), left atrium size, cardiac output, and RV function. This encourages a broader and more complex assessment of parameters reflecting cardiac function in future HFpEF exercise training studies.

Trends in adherence to recommended physical activity and its association with cardiovascular risk factors in US adults with cardiovascular disease: a cross-sectional study

Background

Being physically active is important for cardiovascular health. This study aimed to examine the trend in adherence to the physical activity guidelines (PAG) for aerobic activity among US adults with a history of cardiovascular disease (CVD) and evaluated its association with cardiovascular risk factors.

Methods

We studied participants from the national health and nutrition examination survey 2007–08 to 2017–18. Regression models were used to evaluate the significance of the trend and the association between adherence to the PAG with cardiovascular risk factors.

Results

A total of 3638 participants were reported to have a history of CVD. The proportion of adherence to PAG significantly increased from 41.5% in 2007–08 to 54.3% in 2017–18. Males had a higher proportion of adherence compared to the females, while the trend in adherence was only significant in females. Adherence to the PAG was significantly associated with decreased levels of waist circumference, body mass index, hemoglobin A1c, and triglycerides.

Conclusions

There is a significant increase in the proportion of adherence to the PAG among US adults with a history of CVD from 2007–08 to 2017–18, and adherence to the PAG was associated with improvement in cardiovascular risk factors.

A Contemporary Review of the Effects of Exercise Training on Cardiac Structure and Function and Cardiovascular Risk Profile: Insights From Imaging

Exercise is a commonly prescribed therapy for patients with established cardiovascular disease or those at high risk for de novo disease. Exercise-based, multidisciplinary programs have been associated with improved clinical outcomes post myocardial infarction and is now recommended for patients with cancer at elevated risk for cardiovascular complications. Imaging studies have documented numerous beneficial effects of exercise on cardiac structure and function, vascular function and more recently on the cardiovascular risk profile. In this contemporary review, we will discuss the effects of exercise training on imaging-derived cardiovascular outcomes. For cardiac imaging via echocardiography or magnetic resonance, we will review the effects of exercise on left ventricular function and remodeling in patients with established or at risk for cardiac disease (myocardial infarction, heart failure, cancer survivors), and the potential utility of exercise stress to assess cardiac reserve. Exercise training also has salient effects on vascular function and health including the attenuation of age-associated arterial stiffness and thickening as assessed by Doppler ultrasound. Finally, we will review recent data on the relationship between exercise training and regional adipose tissue deposition, an emerging marker of cardiovascular risk. Imaging provides comprehensive and accurate quantification of cardiac, vascular and cardiometabolic health, and may allow refinement of risk stratification in select patient populations. Future studies are needed to evaluate the clinical utility of novel imaging metrics following exercise training.

Physical Exercise Promotes a Reduction in Cardiac Fibrosis in the Chronic Indeterminate Form of Experimental Chagas Disease

Chagas disease (CD), caused by the protozoan Trypanosoma cruzi, is a neglected tropical disease and a health problem in Latin America. Etiological treatment has limited effectiveness in chronic CD; thus, new therapeutic strategies are required. The practice of physical exercises has been widely advocated to improve the quality of life of CD patients. The most frequent clinical CD manifestation is the chronic indeterminate form (CIF), and the effect of physical exercises on disease progression remains unknown. Here, in a CIF model, we aimed to evaluate the effect of physical exercises on cardiac histological, parasitological, mitochondrial, and oxidative metabolism, electro and echocardiographic profiles, and immunological features. To establish a CIF model, BALB/c and C57BL/6 mice were infected with 100 and 500 trypomastigotes of the Y T. cruzi strain. At 120 days postinfection (dpi), all mouse groups showed normal PR and corrected QT intervals and QRS complexes. Compared to BALB/c mice, C57BL/6 mice showed a lower parasitemia peak, mortality rate, and less intense myocarditis. Thus, C57BL/6 mice infected with 500 parasites were used for subsequent analyses. At 120 dpi, a decrease in cardiac mitochondrial oxygen consumption and an increase in reactive oxygen species (ROS) were detected. When we increased the number of analyzed mice, a reduced heart rate and slightly prolonged corrected QT intervals were detected, at 120 and 150 dpi, which were then normalized at 180 dpi, thus characterizing the CIF. Y-infected mice were subjected to an exercise program on a treadmill for 4 weeks (from 150 to 180 dpi), five times per week in a 30–60-min daily training session. At 180 dpi, no alterations were detected in cardiac mitochondrial and oxidative metabolism, which were not affected by physical exercises, although ROS production increased. At 120 and 180 dpi, comparing infected and non-infected mice, no differences were observed in the levels of plasma cytokines, indicating that a crucial biomarker of the systemic inflammatory profile was absent and not affected by exercise. Compared with sedentary mice, trained Y-infected mice showed similar parasite loads and inflammatory cells but reduced cardiac fibrosis. Therefore, our data show that physical exercises promote beneficial changes that may prevent CD progression.

Neuroprotective Effects of Physical Activity via the Adaptation of Astrocytes

The multifold benefits of regular physical exercise have been largely demonstrated in human and animal models. Several studies have reported the beneficial effects of physical activity, both in peripheral tissues and in the central nervous system (CNS). Regular exercise improves cognition, brain plasticity, neurogenesis and reduces the symptoms of neurodegenerative diseases, making timeless the principle of “mens sana in corpore sano” (i.e., a healthy mind in a healthy body). Physical exercise promotes morphological and functional changes in the brain, acting not only in neurons but also in astrocytes, which represent the most numerous glial cells in the brain. The multiple effects of exercise on astrocytes comprise the increased number of new astrocytes, the maintenance of basal levels of catecholamine, the increase in glutamate uptake, the major release of trophic factors and better astrocytic coverage of cerebral blood vessels. The purpose of this review is to highlight the effects of exercise on brain function, emphasize the role of astrocytes in the healthy CNS, and provide an update for a better understanding of the effects of physical exercise in the modulation of astrocyte function.

The effectiveness of cardiac rehabilitation in non-ischemic dilated cardiomyopathy patients: A pilot study

BACKGROUND/PURPOSE

We aimed to investigate the efficacy of cardiac rehabilitation (CR) through parameters of cardiopulmonary exercise testing (CPET) and echocardiography in non-ischemic dilated cardiomyopathy (DCM) patients.

METHODS

We retrospectively identified non-ischemic DCM patients through medical records (between October 2011 and October 2018) in rehabilitation outpatient-clinics. Patients were divided into rehabilitation and control groups. Patients in the rehabilitation group eligible for inclusion had CR for 3-6 months. Control group patients were without rehabilitation. We recorded CPET and echocardiography parameters at the baseline and follow-up time-points. For safety evaluation, we investigated all adverse effects during training sessions. We utilized Mann-Whitney U test for between- and Wilcoxon signed-rank test for within-group comparisons.

RESULTS

Twenty-five patients (14 in rehabilitation and 11 in control group) were included. In the rehabilitation group, significantly increased peak V˙O₂/kg, peak V˙O₂%, peak workload and peak O₂ pulse were observed after completing CR, and echocardiographic parameters including left ventricular ejection fraction and end-systolic volume. Rehabilitation group patients demonstrated better improvement (change from the baseline) in peak V˙O₂/kg, peak V˙O₂% and peak workload vs. control. No adverse effects during rehabilitation trainings were observed.

CONCLUSION

For non-ischemic DCM, rehabilitation led to superior cardiopulmonary outcomes vs. no rehabilitation, without adverse effects.

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.

Left ventricular ejection fraction as therapeutic target: is it the ideal marker?

Heart failure (HF) consists the fastest growing clinical cardiac disease. HF patients are categorized on the basis of underlying left ventricular ejection fraction (LVEF) into HF with preserved EF (HFpEF), reduced LVEF (HFrEF), and mid-range LVEF (HFmrEF). While LVEF is the most commonly used surrogate marker of left ventricular (LV) systolic function, the implementation of two-dimensional echocardiography in estimating this parameter imposes certain caveats on current HF classification. Most importantly, LVEF could fluctuate in repeated measurements or even recover after treatment, thus blunting the borders between proposed categories of HF and enabling upward classification of patients. Under this prism, we sought to summarize possible procedures to improve systolic function in patients with HFrEF either naturally or by the means of pharmacologic and non-pharmacologic treatment and devices. Therefore, we reviewed established pharmacotherapy, including beta-blockers, inhibitors of renin-angiotensin-aldosterone axis, statins, and digoxin as well as novel treatments like sacubitril-valsartan, ranolazine, and ivabradine. In addition, we assessed evidence in favor of cardiac resynchronization therapy and exercise training programs. Finally, innovative therapeutic strategies, including stem cells, xanthine oxidase inhibitors, antibiotic regimens, and omega-3 polyunsaturated fatty acids, were also taken into consideration. We concluded that LVEF is subject to changes in HF after intervention and besides the aforementioned HFrEF, HFpEF, and HFmrEF categories, a new entity of HF patients with recovered LVEF should be acknowledged. An improved global and refined LV function assessment by sophisticated imaging modalities and circulating biomarkers is expected to render HF classification more accurate and indicate patients with viable-yet dysfunctional-myocardium and favorable characteristics as the ideal candidates for LVEF recovery by individualized HF therapy.

Molecular effects of exercise training in patients with cardiovascular disease: focus on skeletal muscle, endothelium, and myocardium

For decades, we have known that exercise training exerts beneficial effects on the human body, and clear evidence is available that a higher fitness level is associated with a lower incidence of suffering premature cardiovascular death. Despite this knowledge, it took some time to also incorporate physical exercise training into the treatment plan for patients with cardiovascular disease (CVD). In recent years, in addition to continuous exercise training, further training modalities such as high-intensity interval training and pyramid training have been introduced for coronary artery disease patients. The beneficial effect for patients with CVD is clearly documented, and during the last years, we have also started to understand the molecular mechanisms occurring in the skeletal muscle (limb muscle and diaphragm) and endothelium, two systems contributing to exercise intolerance in these patients. In the present review, we describe the effects of the different training modalities in CVD and summarize the molecular effects mainly in the skeletal muscle and cardiovascular system.

Cardiac rehabilitation program in patients with Chagas heart failure: a single-arm pilot study

INTRODUCTION

The benefit of a cardiac rehabilitation (CR) program for patients with Chagas heart failure (CHF) remains unclear. Therefore, we aimed to investigate the effects of CR for CHF patients.

METHODS

A single-arm pilot study, including 12 patients with CHF, was performed. Patients participated in an 8-month physical exercise intervention, comprising aerobic, strength, and stretching exercises (3 times per week, 60 minutes per session). Nutritional and pharmaceutical counseling were also performed. Functional capacity (cardiopulmonary exercise test), muscle respiratory strength (manovacuometry), and body composition (anthropometry and skinfolds) were evaluated at baseline, and after 4 and 8 months of intervention. Cardiac function (echocardiography), biomarkers (lipid profile, glucose, and glycated hemoglobin) and quality of life (Minnesota Living with Heart Failure Questionnaire) were assessed at baseline and at the end of the intervention.

RESULTS

Seven of 12 patients included in the study completed the 8-month follow-up period. Only 2 moderate adverse events occurred during the exercise training. Functional capacity improved after 4 months of CR, while left ventricular ejection fraction (LVEF) and respiratory strength improved after 8 months. Patients with right ventricular (RV) dysfunction at baseline exhibited an improvement in functional capacity after 4 months, and improvements in left ventricular (LV) diastolic pressure, respiratory strength, and quality of life at the end of follow-up. Conversely, those with normal baseline RV function demonstrated LVEF increases that were not observed in patients with RV dysfunction.

CONCLUSIONS

CR was feasible, safe, and has important clinical benefits for patients with CHF, specifically for cardiac function and muscle respiratory strength.

High-Intensity Training Improves Global and Segmental Strains in Severe Congestive Heart Failure

BACKGROUND

High-intensity training (HIT) is superior to moderate aerobic training (MAT) for improving quality of life in congestive heart failure (CHF) patients. Speckle-tracking echocardiography (STE) has recently been suggested for estimation of left ventricle global and regional function. We evaluated the utility of STE for characterizing differences in cardiac function following MAT or HIT in a CHF rat model.

METHODS AND RESULTS

After baseline physiologic assessment, CHF was induced by means of coronary artery ligation in Sprague-Dawley rats. Repeated measurements confirmed the presence of CHF (ejection fraction 52 ± 10%, global circumferential strain (GCS) 10.5 ± 4, and maximal oxygen uptake (V˙O_2max) 71 ± 11 mL⋅min^-1⋅kg^-1; P < .001 vs baseline for all). Subsequently, rats were divided into training protocols: sedentary (SED), MAT, or HIT. After the training period, rats underwent the same measurements and were killed. Training intensity improved V˙O_2max (73 ± 13 mL⋅min^-1⋅kg^-1 in MAT [P < .01 vs baseline] and 82 ± 6 mL⋅min^-1⋅kg^-1 in HIT [P < .05 vs baseline or SED] and ejection fraction (50 ± 21% in MAT [P < .001 vs baseline] and 66 ± 7% in HIT [P > .05 vs baseline]). In addition, strains of specific segments adjacent to the infarct zone regained basal values (P > .05 vs baseline), whereas global cardiac functional parameters as assessed with the use of 2-dimensional echocardiography did not improve.

CONCLUSIONS

High-intensity exercise training improved function in myocardial segments remote from the scar, which resulted in compensatory cardiac remodeling. This effect is prominent, yet it could be detected only with the use of STE.

Exercise-Based Rehabilitation for Heart Failure: Clinical Evidence

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

Growing Relevance of Cardiac Rehabilitation for an Older Population With Heart Failure

Cardiac rehabilitation (CR) is a comprehensive lifestyle program that can have particular benefit for older patients with heart failure (HF). Prevalence of HF is increasingly common among older adults. Mounting effects of cardiovascular risk factors in older age as well as the added effects of geriatric syndromes such as multimorbidity, frailty, and sedentariness contribute to the high incidence of HF as well as to management difficulty. CR can play a decisive role in improving function, quality of life, symptoms, morbidity, and mortality, and also address the idiosyncratic complexities of care that often arise in old age. Unfortunately, the current policies and practices regarding CR for patients with HF are limited to HF with reduced ejection fraction and do not extend to HF with preserved ejection fraction, which is likely undercutting its full potential to improve care for today's aging population. Despite the strong rationale for CR on important clinical outcomes, it remains underused, particularly among older patients with HF. In this review, we discuss both the potential and the limitations of contemporary CR for older adults with HF.

The Effect of Cardiac Rehabilitation Exercise Training on Cardiopulmonary Function in Ischemic Cardiomyopathy With Reduced Left Ventricular Ejection Fraction

OBJECTIVE

To observe the effect and safety of cardiac rehabilitation (CR) exercise in ischemic cardiomyopathy and to compare the results between patients with preserved left ventricular ejection fraction (LVEF) and reduced LVEF.

METHODS

Patients with ischemic cardiomyopathy with LVEF <50% were included as subjects. The patients were classified into the preserved LVEF (pLVEF; LVEF 41%-49%) group and the reduced LVEF (rLVEF; LVEF ≤40%) group. Patients underwent hourly aerobic exercise training sessions with an intensity of 60%-85% of heart rate reserve, three times a week for 6 weeks. Graded exercise test and transthoracic echocardiogram were performed in all study patients before and after completion of the CR exercise program.

RESULTS

After completion of the CR exercise program, both groups (pLVEF, n=30; rLVEF, n=18) showed significant increases in LVEF and VO2max. In the pLVEF group, LVEF and VO2max increased from 45.1%±4.8% to 52.5%±9.6% (p<0.001) and from 24.1±6.3 to 28.1±8.8 mL/kg/min (p=0.002), respectively. In the rLVEF group, LVEF and VO2max increased from 29.7%±7.7% to 37.6%±10.3% (p<0.001) and from 17.6±4.7 to 21.2±5.1 mL/kg/min (p<0.001), respectively. Both groups completed their exercise program safely.

CONCLUSION

In both groups, patients with ischemic cardiomyopathy who completed a 6-week supervised CR exercise program demonstrated remarkable improvements in cardiopulmonary function. This result implies that neither of the two groups showed higher efficacy in comparison to each other, but we can conclude that CR exercise in the rLVEF group was as effective and safe as that in the pLVEF group.

Endurance Exercise Training in Young Adults with Barth Syndrome: A Pilot Study

BACKGROUND

Barth syndrome (BTHS) is a rare X-linked disorder that is characterized by mitochondrial abnormalities, cardio-skeletal myopathy, exercise intolerance, and premature mortality. The effect on endurance exercise training on exercise tolerance, cardio-skeletal function, and quality of life in BTHS is unknown.

METHODS

Four young adults (23 ± 5 years, n = 4) with BTHS participated in a 12-week, supervised, individualized endurance exercise training program. Exercise training was performed on a cycle ergometer for 30-45' three times per week at a moderate intensity level. Exercise tolerance was measured by graded exercise testing and peak oxygen consumption, heart function via two-dimensional and M-mode echocardiography, skeletal muscle function by near-infrared spectroscopy, and quality of life through the Minnesota Living with Heart Failure questionnaire.

RESULTS

There were no adverse events during exercise testing or training for any participant. Peak oxygen consumption modestly (~5%) improved in three or four participants. Mean quality of life questions regarding dyspnea and side effects from medications significantly improved following exercise training. Mean resting heart function or skeletal muscle oxygen extraction during exercise did not improve after exercise training.

CONCLUSION

Endurance exercise training is safe and appears to modestly improve peak exercise tolerance and certain measures of quality of life in young adults with BTHS. However, compared to improvements resulting from endurance exercise training seen in other non-BTHS mitochondrial myopathies and heart failure, these improvements appear blunted. Further research into the most beneficial mode, intensity and frequency of exercise training in BTHS is warranted.

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

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

Safety and efficacy of exercise training in elderly heart failure patients: a systematic review and meta-analysis

OBJECTIVES

It is unclear whether exercise training is effective and safe for elderly patients with chronic heart failure (CHF). The purpose of this meta-analysis was to systematically analyse the completed trials assessing the safety and efficacy of exercise training in elderly patients with heart failure.

METHODS

We searched electronic databases up to September 2012 for randomised controlled trials (RCTs) evaluating exercise training in the elderly heart failure patients (≥ 60 years). The safety and efficacy of exercise training were assessed by all-cause mortality, hospitalisations, 6-min walking distance (6MWD), peakVO2 and/or health-related quality of life (HRQoL).

RESULTS

Seven prospective RCTs were included with a total of 530 patients, and the patients' mean age ranged from 70 to 81 years. The majority were male, low-to-medium risk and New York Heart Association class II and III with a left ventricular ejection fraction of < 45%. Exercise training increased the 6MWD significantly by 50.05 m (95% CI: 28.37-71.73) and improved generic HRQoL (95% CI: 0.06-0.18). There was no significant difference in mortality, hospitalisations, peakVO2 and disease-specific HRQoL between exercise group and control group.

CONCLUSIONS

In elderly CHF patients (mean age 70-81), exercise training increase 6MWD and improve generic HRQoL, but has no effects on mortality, hospitalisations, peakVO2 and disease-specific HRQoL. The long-term efficacy and safety of exercise training in elderly heart failure patients require further study based on large and rational-designed controlled clinical trials.

The role of B-type natriuretic Peptide testing in guiding outpatient heart failure treatment

OPINION STATEMENT

While heart failure (HF) treatment guidelines exist, there are significant gaps in their implementation owing in part to the lack of objective data to help guide clinicians in their medical decision-making. B-type natriuretic peptide (BNP) and its amino-terminal equivalent (NT-proBNP) are objective markers of HF prognosis, are useful to monitor response to treatment in outpatients with HF, and may have a role in "guiding" HF care as well. Successful BNP or NT-proBNP guided HF treatment requires regular attempts to reach and maintain target values (BNP ≤ 125 pg/mL or NT-proBNP ≤ 1000 pg/mL). This may be achieved through lifestyle modifications, exercise programs, medication adjustments, and therapeutic interventions shown to reduce morbidity and mortality in HF patients. Failure to achieve biomarker targets portends a worse prognosis, proportional to the lowest achieved natriuretic peptide concentration; in those with significant biomarker "nonresponse," prognosis is poor, and alternative therapeutic strategies should be considered.