Exercise Intolerance in Patients With Heart Failure: JACC State-of-the-Art Review

Unraveling the link between cardiorespiratory fitness and cancer: a state-of-the-art review

Cardiorespiratory fitness (CRF) not only reflects an individual's capacity to perform physical activities but also encapsulates broader effects on the basic biology of aging. This review aims to summarize the evidence on the influence of CRF on overall and site-specific cancer risks. It delves into the biological mechanisms through which CRF may exert its effects, explores the clinical implications of these findings, identifies gaps in the current evidence base, and suggests directions for future research. The synthesis of findings reveals that higher CRF levels (general threshold of > 7 METs) are consistently associated with a reduced risk of a range of cancers, including head and neck, lung, breast, gastrointestinal, particularly pancreatic and colorectal, bladder, overall cancer incidence and mortality, and potentially stomach and liver, bile duct, and gall bladder cancers. These inverse associations between CRF and cancer risk do not generally differ across age groups, sex, race, or adiposity, suggesting a universal protective effect of CRF. Nonetheless, evidence linking CRF with skin, mouth and pharynx, kidney, and endometrial cancers is limited and inconclusive. Conversely, higher CRF levels may be potentially linked to an increased risk of prostate cancer and hematological malignancies, such as leukemia and myeloma, although the evidence is still not conclusive. CRF appears to play a significant role in reducing the risk of several cancers through various biological mechanisms, including inflammation reduction, immune system enhancement, hormonal regulation, and metabolic improvements. Overall, enhancing CRF through regular physical activity offers a vital, accessible strategy for reducing cancer risk and extending the health span. Future research should aim to fill the existing evidence gaps regarding specific cancers and elucidate the detailed dose-response relationships between CRF levels and cancer risk. Studies are also needed to elucidate the causal relationships and mechanistic pathways linking CRF to cancer outcomes.

Sarcopenia: A dive into metabolism to promote a multimodal, preventive, and regenerative approach

Sarcopenia, the age-related loss of skeletal muscle mass and function, poses a significant challenge in the field of geriatrics and gerontology, impacting the health and independence of older adults. Understanding and addressing sarcopenia is crucial for optimizing clinical outcomes and enhancing the quality of life along with aging. By synthesizing current research findings and theoretical frameworks, this review elucidates the multifaceted mechanisms underlying sarcopenia, mainly focusing on energy balance and metabolic processes. Furthermore, the manuscript explores the implications of sarcopenia on overall health outcomes, functional decline, and quality of life in older individuals. The study concludes with a perspective on the role of preventive and regenerative medicine in sarcopenia, where the two main lifestyle pillars (exercise and diet) represent key factors.

Novel Techniques, Biomarkers and Molecular Targets to Address Cardiometabolic Diseases

Cardiometabolic diseases (CMDs) are interrelated and multifactorial conditions, including arterial hypertension, type 2 diabetes, heart failure, coronary artery disease, and stroke. Due to the burden of cardiovascular morbidity and mortality associated with CMDs' increasing prevalence, there is a critical need for novel diagnostic and therapeutic strategies in their management. In clinical practice, innovative methods such as epicardial adipose tissue evaluation, ventricular-arterial coupling, and exercise tolerance studies could help to elucidate the multifaceted mechanisms associated with CMDs. Similarly, epigenetic changes involving noncoding RNAs, chromatin modulation, and cellular senescence could represent both novel biomarkers and targets for CMDs. Despite the promising data available, significant challenges remain in translating basic research findings into clinical practice, highlighting the need for further investigation into the complex pathophysiology underlying CMDs.

Anemia in Heart Failure: A Perspective from 20-Year Bibliometric Analysis

Background & Objective

Anemia in patients with heart failure (HF) is a growing concern. However, there has no bibliometric analysis in this area up to now. The aim of this study is to explore the status and trends in the field of anemia in HF through the bibliometric analysis, and to provide an outlook on future research.

Methods

We retrieved publications from the Web of Science Core Collection database, and the following data analysis and visualization tools were utilized to perform data processing, statistical computing and graphics generation: VOSviewer (v.1.6.18), CiteSpace (v.6.2 R5), Scimago Graphica (v.1.0.36), Biblimatrix and Microsoft Excel.

Results

We identified a total of 3490 publications from 2004 to 2023. The publications in the field of anemia in HF are growing steadily. The United States, the United Kingdom, and Italy were the leading countries in this area. Stefan D Anker, as the most influential author, held the most total citations and publications. Harvard University was the most productive institution in this area. The European Journal of Heart Failure had published the most papers. Through the analysis of co-citations, 14 major clusters based on cluster labels were identified. Keyword analysis showed that mortality, outcome, prevalence, and risk were the most frequent keywords, and the potential research hotspots in the future will be intravenous iron and iron deficiency.

Conclusion

This study provides a comprehensive analysis of countries, authors, institutions, journals, co-cited references, and keywords in the field of anemia in HF through bibliometric analysis and data visualization. The status, hotspots and future trends in this field offer a reference for in-depth research. Further studies are necessary in the future to broaden the spectrum of research in this field, to evaluate comprehensive approaches to treating anemia in patients with HF, and to find rational targets for the management of anemia.

Cardiopulmonary determinants of reduced exercise tolerance in Fabry disease

Fabry disease (FD), also known as Anderson-Fabry disease, is a hereditary disorder of glycosphingolipid metabolism, caused by a deficiency of the lysosomal alpha-galactosidase A enzyme. This causes a progressive accumulation of glycosphingolipids in tissues and organs which represents the main pathogenetic mechanism of FD. The disease is progressive and multisystemic and is characterized by early symptoms and late complications (renal, cardiac and neurological dysfunction). Fatigue and exercise intolerance are early common symptoms in FD patients but the specific causes are still to be defined. In this narrative review, we deal with the contribution of cardiac and pulmonary dysfunctions in determining fatigue and exercise intolerance in FD patients.

Hemoglobin is an independent predictor of improvement exercise tolerance in male patients with non-ischemic cardiomyopathy

Exercise intolerance is a symptom of chronic heart failure (CHF). The magnitude of exercise tolerance, as measured by peak oxygen uptake (peak VO2), is strongly associated with prognosis in patients with CHF. We aimed to evaluate the factors associated with improved exercise tolerance in patients with HF. In this prospective study, we recruited patients who were diagnosed with non-ischemic cardiomyopathy between September 2017 and September 2021. All patients underwent cardiopulmonary exercise testing at discharge and 6 months after enrollment. The patients were stratified according to whether peak VO2 was increased or not at 6 months. One hundred patients with a reduced left-ventricular ejection fraction (LVEF < 50%) were enrolled. Improvement of peak VO2 was observed in 74 patients. In male patients, hemoglobin level was higher in the increased peak VO2 group than in the non-increased group (15.0 ± 1.9 g/dL vs. 13.1 ± 2.1 g/dL; p < 0.01). Baseline hemoglobin level was positively correlated with the percentage change in peak VO2 (Spearman's r = 0.248, p = 0.040). Kaplan-Meier analysis demonstrated that adverse cardiac events were significantly less frequent in the increased peak VO2 group than in the non-increased group (log-rank test, p = 0.032). Multivariate logistic regression analysis identified hemoglobin level as an independent predictor of improved peak VO2 [odds ratio (OR) 1.60; 95% confidence interval (CI) 1.05-2.44; p = 0.027]. Baseline hemoglobin level is an independent predictor of improved peak VO2 in male patients with non-ischemic cardiomyopathy.

Phenotyping cardiopulmonary exercise testing measures in heart failure with reduced ejection fraction: A comparison between Italy and Brazil

BACKGROUND

While patients with heart failure (HF) with reduced left ventricular ejection fraction (HFrEF) constitutes a global health crisis the incidence, prevalence and prognosis of the disease may differ depending on the continent and country.

OBJECTIVE

To profile, analyze and compare cardiopulmonary exercise testing (CPET) data of patients with HFrEF between Italian and Brazilian cohorts.

METHODS

In this observational study, a total of 630 patients with clinical and functional diagnosis of HFrEF (315 patients from Brazil and 315 patients from Italy) performed CPET.

RESULTS

Although Brazilian patients were slightly younger (Brazil 60±10 vs Italy 64±11 p<0.001) with a better peak oxygen consumption (V̇O2), circulatory power and left ventricular ejection fraction (LVEF) (p<0.01), ventilatory inefficiency and oscillation ventilation was higher when compared to the Italian cohort. When stratifying patients with LVEF≤30 % and age≥60 years, Brazilian patients presented worse ventilatory efficiency, and lower peak V̇O2 compared to the Italian cohort.

CONCLUSION

Patients with HFrEF from Brazil exhibited higher ventilatory inefficiency and a greater prevalence of oscillatory ventilation during CPET compared to patients with the same diagnosis from Italy.

Inspiratory muscle endurance is similarly reduced in the early and late stages of chronic Chagas heart disease

OBJECTIVE

Inspiratory muscle strength (IMS) appears to be reduced in subjects with chronic Chagas heart disease (CHD), especially in the presence of heart failure (HF). However, only one study about IMS and inspiratory muscle endurance (IME) in those with CHD without heart failure is available. This study aimed to compare IMS and IME in subjects with CHD in the presence and absence of HF.

METHODS

This is a cross-sectional study in which 30 CHD adult patients were divided into CHD-CC group (initial phase of CHD, without HF; n = 15) and CHD-HF group (advanced phase of CHD, with HF; n = 15). We assessed IMS by maximum inspiratory pressure (MIP) and IME by incremental (Pthmax) and constant load (TLim) tests. Reduced IMS and IME were considered by predicted MIP values <70% and Pthmax/MIP <75%, respectively.

RESULTS

Inspiratory muscle weakness (IMW) was more frequent in CHD-HF than in CHD-CC (46.7% vs. 13.3%; p = 0.05), and both groups had high frequencies of reduced IME (93.3% CHD-CC vs. 100.0% CHD-HF; p = 0.95). Age-adjusted logistic regression analysis using HF as a dependent variable showed that HF was associated with an increased chance of IMW compared with the CHD-CC group (OR = 7.47; p = 0.03; 95% CI 1.20-46.19).

CONCLUSION

This study suggests that, in patients with CHD, HF is associated with IMW, and that reduction of IME is already present in the initial phase, similar to the advanced phase with HF.

Physical activity changes and related factors in chronic heart failure patients during the postdischarge transition period: a longitudinal study

BACKGROUND

Physical activity (PA) is essential and effective for chronic heart failure (CHF) patients. A greater understanding of the longitudinal change in PA and its influencing factors during the postdischarge transition period may help create interventions for improving PA. The aims of this study were (1) to compare the change in PA, (2) to examine the influencing factors of PA change, and (3) to verify the mediating pathways between influencing factors and PA during the postdischarge transition period in CHF patients.

METHODS

A total of 209 CHF patients were recruited using a longitudinal study design. The Chinese version of the International Physical Activity Questionnaire (IPAQ), Patient-reported Outcome Measure for CHF (CHF-PRO), and the Chinese version of the Tampa Scale for Kinesiophobia Heart (TSK-Heart) were used to assess PA, CHF-related symptoms, and kinesiophobia. The IPAQ score was calculated (1) at admission, (2) two weeks after discharge, (3) two months after discharge, and (4) three months after discharge. Two additional questionnaires were collected during admission. Generalized estimating equation (GEE) models were fitted to identify variables associated with PA over time. We followed the STROBE checklist for reporting the study.

RESULTS

The PA scores at the four follow-up visits were 1039.50 (346.50-1953.00) (baseline/T1), 630.00 (1.00-1260.00) (T2), 693.00 (1-1323.00) (T3) and 693.00 (160.88-1386.00) (T4). The PA of CHF patients decreased unevenly, with the lowest level occurring two weeks after discharge, and gradually improving at two and three months after discharge. CHF-related symptoms and kinesiophobia were significantly associated with changes in PA over time. Compared with before hospitalization, an increase in CHF-related symptoms at two weeks and two months after discharge was significantly associated with decreased PA. According to our path analysis, CHF-related symptoms were positively and directly associated with kinesiophobia, and kinesiophobia was negatively and directly related to PA. Moreover, CHF-related symptoms are indirectly related to PA through kinesiophobia.

CONCLUSION

PA changed during the postdischarge transition period and was associated with CHF-related symptoms and kinesiophobia in CHF patients. Reducing CHF-related symptoms helps improve kinesiophobia in CHF patients. In addition, the reduction in CHF-related symptoms led to an increase in PA through the improvement of kinesiophobia.

TRIAL REGISTRATION

The study was registered in the Chinese Clinical Trial Registry (11/10/2022 ChiCTR2200064561 retrospectively registered).

Effect of an exercise-based cardiac rehabilitation program on quality of life of patients with chronic Chagas cardiomyopathy: results from the PEACH randomized clinical trial

To investigate the effect of an exercise-based cardiac rehabilitation program on the quality of life (QoL) of patients with chronic Chagas cardiomyopathy (CCC). PEACH study was a single-center, superiority randomized clinical trial of exercise training versus no exercise (control). The sample comprised Chagas disease patients with CCC, left ventricular ejection fraction < 45%, without or with HF symptoms (CCC stages B2 or C, respectively). QoL was assessed at baseline, after three months, and at the end of six months of follow-up using the SF-36 questionnaire. Patients randomized for the exercise group (n = 15) performed exercise training (aerobic, strength and stretching exercises) for 60 min, three times a week, during six months. Patients in the control group (n = 15) were not provided with a formal exercise prescription. Both groups received identical nutritional and pharmaceutical counseling during the study. Longitudinal analysis of the effects of exercise training on QoL, considering the interaction term (group × time) to estimate the rate of changes between groups in the outcomes (represented as beta coefficient), was performed using linear mixed models. Models were fitted adjusting for each respective baseline QoL value. There were significant improvements in physical functioning (β =  + 10.7; p = 0.02), role limitations due to physical problems (β =  + 25.0; p = 0.01), and social functioning (β =  + 19.2; p < 0.01) scales during the first three months in the exercise compared to the control group. No significant differences were observed between groups after six months. Exercise-based cardiac rehabilitation provided short-term improvements in the physical and mental aspects of QoL of patients with CCC.Trial registration: ClinicalTrials.gov Identifier: NCT02517632; August 7, 2015.

Real-world walking behaviors are associated with early-stage heart failure: a Project Baseline Health Study

BACKGROUND

Data collected via wearables may complement in-clinic assessments to monitor subclinical heart failure (HF).

OBJECTIVES

Evaluate the association of sensor-based digital walking measures with HF stage and characterize their correlation with in-clinic measures of physical performance, cardiac function and participant reported outcomes (PROs) in individuals with early HF.

METHODS

The analyzable cohort included participants from the Project Baseline Health Study (PBHS) with HF stage 0, A, or B, or adaptive remodeling phenotype (without risk factors but with mild echocardiographic change, termed RF-/ECHO+) (based on available first-visit in-clinic test and echocardiogram results) and with sufficient sensor data. We computed daily values per participant for 18 digital walking measures, comparing HF subgroups vs stage 0 using multinomial logistic regression and characterizing associations with in-clinic measures and PROs with Spearman's correlation coefficients, adjusting all analyses for confounders.

RESULTS

In the analyzable cohort (N=1265; 50.6% of the PBHS cohort), one standard deviation decreases in 17/18 walking measures were associated with greater likelihood for stage-B HF (multivariable-adjusted odds ratios [ORs] vs stage 0 ranging from 1.18-2.10), or A (ORs vs stage 0, 1.07-1.45), and lower likelihood for RF-/ECHO+ (ORs vs stage 0, 0.80-0.93). Peak 30-minute pace demonstrated the strongest associations with stage B (OR vs stage 0=2.10; 95% CI:1.74-2.53) and A (OR vs stage 0=1.43; 95% CI:1.23-1.66). Decreases in 13/18 measures were associated with greater likelihood for stage-B HF vs stage A. Strength of correlation with physical performance tests, echocardiographic cardiac-remodeling and dysfunction indices and PROs was greatest in stage B, then A, and lowest for 0.

CONCLUSIONS

Digital measures of walking captured by wearable sensors could complement clinic-based testing to identify and monitor pre-symptomatic HF.

Leucine Supplementation Prevents the Development of Skeletal Muscle Dysfunction in a Rat Model of HFpEF

Heart failure with preserved ejection fraction (HFpEF) is associated with exercise intolerance due to alterations in the skeletal muscle (SKM). Leucine supplementation is known to alter the anabolic/catabolic balance and to improve mitochondrial function. Thus, we investigated the effect of leucine supplementation in both a primary and a secondary prevention approach on SKM function and factors modulating muscle function in an established HFpEF rat model. Female ZSF1 obese rats were randomized to an untreated, a primary prevention, and a secondary prevention group. For primary prevention, leucine supplementation was started before the onset of HFpEF (8 weeks of age) and for secondary prevention, leucine supplementation was started after the onset of HFpEF (20 weeks of age). SKM function was assessed at an age of 32 weeks, and SKM tissue was collected for the assessment of mitochondrial function and histological and molecular analyses. Leucine supplementation prevented the development of SKM dysfunction whereas it could not reverse it. In the primary prevention group, mitochondrial function improved and higher expressions of mitofilin, Mfn-2, Fis1, and miCK were evident in SKM. The expression of UCP3 was reduced whereas the mitochondrial content and markers for catabolism (MuRF1, MAFBx), muscle cross-sectional area, and SKM mass did not change. Our data show that leucine supplementation prevented the development of skeletal muscle dysfunction in a rat model of HFpEF, which may be mediated by improving mitochondrial function through modulating energy transfer.

Effects of Respiratory Muscle Training on Exercise Capacity, Quality of Life, and Respiratory and Pulmonary Function in People With Ischemic Heart Disease: Systematic Review and Meta-Analysis

OBJECTIVE

This systematic review and meta-analysis aimed to evaluate the effects of respiratory muscle training (RMT) on functional exercise capacity, health-related quality of life (HRQoL), respiratory muscle function, and pulmonary function in individuals with ischemic heart disease (IHD).

METHODS

The MEDLINE, Web of Science, Scopus, PEDro, CINAHL, Science Direct, and CENTRAL electronic databases were searched in January 2023. Randomized controlled trials published in English, Spanish, or Portuguese that were conducted to determine the effect of RMT versus passive control and/or sham RMT on the target variables in individuals with IHD, irrespective of age or sex were included. Two reviewers performed the searches and extraction of the most relevant data. The quality and risk of bias for each included study were examined with the PEDro scale and Cochrane risk-of-bias tool.

RESULTS

Thirteen studies (849 participants) were included. The meta-analysis showed a significant increase in peak oxygen consumption (mean difference [MD] = 2.18 mL·kg-1·min-1 [95% CI = 0.54 to 3.83]), inspiratory muscle strength (MD = 16.62 cm H2O [95% CI = 12.48 to 20.77]), inspiratory muscle endurance (standardized mean difference = 0.39 [95% CI = 0.19 to 0.60]), and expiratory muscle strength (MD = 14.52 cm H2O [95% CI = 5.51 to 23.53]). There were no benefits in 6-minute walking distance (MD = 37.57 m [95% CI = -36.34 to 111.48]), HRQoL (standardized mean difference = 0.22 [95% CI = -0.16 to 0.60]), pulmonary function (forced vital capacity; MD = 2.07% of predicted value [95% CI = -0.90 to 5.03], or forced expiratory volume at the first second (MD = -0.75% of predicted value [95% CI = -5.45 to 3.95]).

CONCLUSION

This meta-analysis provided high- and moderate-quality evidence that inspiratory muscle training (IMT) improves inspiratory muscle strength and endurance, respectively; and very low-quality evidence for effects on peak oxygen consumption and expiratory muscle strength in individuals with IHD. No superior effects were found in the 6-minute walking test, HRQoL, or pulmonary function compared with the control group.

IMPACT

The results shown in this systematic review with meta-analysis will provide clinicians a better understanding of the effects of IMT in people with IHD. IMT could be integrated into the cardiac rehabilitation management, although more research is needed.

Running on empty: Factors underpinning impaired cardiac output reserve in heart failure with preserved ejection fraction

Heart failure with preserved ejection fraction (HFpEF) is frequently attributed etiologically to an underlying left ventricular (LV) diastolic dysfunction, although its pathophysiology is far more complex and can exhibit significant variations among patients. This review endeavours to systematically unravel the pathophysiological heterogeneity by illustrating diverse mechanisms leading to an impaired cardiac output reserve, a central and prevalent haemodynamic abnormality in HFpEF patients. Drawing on previously published findings from our research group, we propose a pathophysiology-guided phenotyping based on the presence of: (1) LV diastolic dysfunction, (2) LV systolic pathologies, (3) arterial stiffness, (4) atrial impairment, (5) right ventricular dysfunction, (6) tricuspid valve regurgitation, and (7) chronotopic incompetence. Tailored to each specific phenotype, we explore various potential treatment options such as antifibrotic medication, diuretics, renal denervation and more. Our conclusion underscores the pivotal role of cardiac output reserve as a key haemodynamic abnormality in HFpEF, emphasizing that by phenotyping patients according to its individual pathomechanisms, insights into personalized therapeutic approaches can be gleaned.

Left ventricle function and post-transcriptional events with exercise training in pigs

BACKGROUND

Standardized exercise protocols have been shown to improve overall cardiovascular fitness, but direct effects on left ventricular (LV) function, particularly diastolic function and relation to post-transcriptional molecular pathways (microRNAs (miRs)) are poorly understood. This project tested the central hypothesis that adaptive LV remodeling resulting from a large animal exercise training protocol, would be directly associated with specific miRs responsible for regulating pathways relevant to LV myocardial stiffness and geometry.

METHODS AND RESULTS

Pigs (n = 9; 25 Kg) underwent a 4 week exercise training protocol (10 degrees elevation, 2.5 mph, 10 min, 5 days/week) whereby LV chamber stiffness (KC) and regional myocardial stiffness (rKm) were measured by Doppler/speckle tracking echocardiography. Age and weight matched non-exercise pigs (n = 6) served as controls. LV KC fell by approximately 50% and rKm by 30% following exercise (both p < 0.05). Using an 84 miR array, 34 (40%) miRs changed with exercise, whereby 8 of the changed miRs (miR-19a, miR-22, miR-30e, miR-99a, miR-142, miR-144, miR-199a, and miR-497) were correlated to the change in KC (r ≥ 0.5 p < 0.05) and mapped to matrix and calcium handling processes. Additionally, miR-22 and miR-30e decreased with exercise and mapped to a localized inflammatory process, the inflammasome (NLRP-3, whereby a 2-fold decrease in NLRP-3 mRNA occurred with exercise (p < 0.05).

CONCLUSION

Chronic exercise reduced LV chamber and myocardial stiffness and was correlated to miRs that map to myocardial relaxation processes as well as local inflammatory pathways. These unique findings set the stage for utilization of myocardial miR profiling to identify underlying mechanisms by which exercise causes changes in LV myocardial structure and function.

The therapeutic potential of ketones in cardiometabolic disease: impact on heart and skeletal muscle

β-Hydroxybutyrate (βOHB) is the major ketone in the body, and it is recognized as a metabolic energy source and an important signaling molecule. While ketone oxidation is essential in the brain during prolonged fasting/starvation, other organs such as skeletal muscle and the heart also use ketones as metabolic substrates. Additionally, βOHB-mediated molecular signaling events occur in heart and skeletal muscle cells, and via metabolism and/or signaling, ketones may contribute to optimal skeletal muscle health and cardiac function. Of importance, when the use of ketones for ATP production and/or as signaling molecules becomes disturbed in the presence of underlying obesity, type 2 diabetes, and/or cardiovascular diseases, these changes may contribute to cardiometabolic disease. As a result of these disturbances in cardiometabolic disease, multiple approaches have been used to elevate circulating ketones with the goal of optimizing either ketone metabolism or ketone-mediated signaling. These approaches have produced significant improvements in heart and skeletal muscle during cardiometabolic disease with a wide range of benefits that include improved metabolism, weight loss, better glycemic control, improved cardiac and vascular function, as well as reduced inflammation and oxidative stress. Herein, we present the evidence that indicates that ketone therapy could be used as an approach to help treat cardiometabolic diseases by targeting cardiac and skeletal muscles.

Identification of Fatigue Subtypes and Their Correlates in Prevalent Heart Failure: A Secondary Analysis of the Atherosclerosis Risk in Communities Study

BACKGROUND

Among patients with heart failure (HF), fatigue is common and linked to quality of life and functional status. Fatigue is hypothesized to manifest as multiple types, with general and exertional components. Unique subtypes of fatigue in HF may require differential assessment and treatment to improve outcomes. We conducted this study to identify fatigue subtypes in persons with prevalent HF in the ARIC study (Atherosclerosis Risk in Communities) and describe the distribution of characteristics across subtypes.

METHODS

We performed a cross-sectional analysis of 1065 participants with prevalent HF at ARIC visit 5 (2011-2013). We measured exertional fatigue using the Modified Medical Research Council Breathlessness scale and general fatigue using the Patient Reported Outcomes Measurement Information System fatigue scale. We used latent class analysis to identify subtypes of fatigue. Number of classes was determined using model fit statistics, and classes were interpreted and assigned fatigue severity rating based on the conditional probability of endorsing survey items given class. We compared characteristics across classes using multinomial regression.

RESULTS

Overall, participants were 54% female and 38% Black with a mean age of 77. We identified 4 latent classes (fatigue subtypes): (1) high general/high exertional fatigue (18%), (2) high general/low exertional fatigue (27%), (3) moderate general/moderate exertional fatigue (20%), and (4) low/no general and exertional fatigue (35%). Female sex, Black race, lower education level, higher body mass index, increased depressive symptoms, and higher prevalence of diabetes were associated with higher levels of general and exertional fatigue.

CONCLUSIONS

We identified unique subtypes of fatigue in patients with HF who have not been previously described. Within subtype, general and exertional fatigue were mostly concordant in severity, and exertional fatigue only occurred in conjunction with general fatigue, not alone. Further understanding these fatigue types and their relationships to outcomes may enhance our understanding of the symptom experience and inform prognostication and secondary prevention efforts for persons with HF.

Body Composition, Coronary Microvascular Dysfunction, and Future Risk of Cardiovascular Events Including Heart Failure

BACKGROUND

Body mass index (BMI) is a controversial marker of cardiovascular prognosis, especially in women. Coronary microvascular dysfunction (CMD) is prevalent in obese patients and a better discriminator of risk than BMI, but its association with body composition is unknown.

OBJECTIVES

The authors used a deep learning model for body composition analysis to investigate the relationship between CMD, skeletal muscle (SM), subcutaneous adipose tissue (SAT), and visceral adipose tissue (VAT), and their contribution to adverse outcomes in patients referred for evaluation of coronary artery disease.

METHODS

Consecutive patients (n = 400) with normal perfusion and preserved left ventricular ejection fraction on cardiac stress positron emission tomography were followed (median, 6.0 years) for major adverse events, including death and hospitalization for myocardial infarction or heart failure. Coronary flow reserve (CFR) was quantified as stress/rest myocardial blood flow from positron emission tomography. SM, SAT, and VAT cross-sectional areas were extracted from abdominal computed tomography at the third lumbar vertebra using a validated automated algorithm.

RESULTS

Median age was 63, 71% were female, 50% non-White, and 50% obese. Compared with the nonobese, patients with obesity (BMI: 30.0-68.4 kg/m2) had higher SAT, VAT, and SM, and lower CFR (all P < 0.001). In adjusted analyses, decreased SM but not increased SAT or VAT was significantly associated with CMD (CFR <2; OR: 1.38; 95% CI: 1.08-1.75 per -10 cm2/m2 SM index; P < 0.01). Both lower CFR and SM, but not higher SAT or VAT, were independently associated with adverse events (HR: 1.83; 95% CI: 1.25-2.68 per -1 U CFR and HR: 1.53; 95% CI: 1.20-1.96 per -10 cm2/m2 SM index, respectively; P < 0.002 for both), especially heart failure hospitalization (HR: 2.36; 95% CI: 1.31-4.24 per -1 U CFR and HR: 1.87; 95% CI: 1.30-2.69 per -10 cm2/m2 SM index; P < 0.004 for both). There was a significant interaction between CFR and SM (adjusted P = 0.026), such that patients with CMD and sarcopenia demonstrated the highest rate of adverse events, especially among young, female, and obese patients (all P < 0.005).

CONCLUSIONS

In a predominantly female cohort of patients without flow-limiting coronary artery disease, deficient muscularity, not excess adiposity, was independently associated with CMD and future adverse outcomes, especially heart failure. In patients with suspected ischemia and no obstructive coronary artery disease, characterization of lean body mass and coronary microvascular function may help to distinguish obese phenotypes at risk for cardiovascular events.

Prognostic Value of Hemodynamic Gain Index in Patients With Heart Failure With Reduced Ejection Fraction

BACKGROUND

Assessment of functional capacity in patients with heart failure with reduced ejection fraction (HFrEF) is essential for risk stratification, and it traditionally relied on cardiopulmonary exercise testing (CPET)-derived peak oxygen consumption (peak Vo2).

OBJECTIVES

This study sought to investigate the prognostic value of alternative nonmetabolic exercise testing parameters in a contemporary cohort with HFrEF.

METHODS

Medical records of 1,067 consecutive patients with chronic HFrEF who underwent CPET from December 2012 to September 2020 were reviewed for a primary outcome that was a composite of all-cause mortality, left ventricular assist device implantation, and/or heart transplantation. Multivariable Cox regression and log-rank testing were used to determine prognostic values of various exercise testing variables.

RESULTS

The primary outcome was identified in 331 of 954 patients (34.7%) of the HFrEF cohort (median follow-up time, 946 days). After adjustment for demographics, cardiac parameters, and comorbidities, higher hemodynamic gain index (HGI) and peak rate-pressure product (RPP) were associated with greater event-free survival (adjusted HR per doubling: 0.76 and 0.36; 95% CI: 0.67-0.87 and 0.28-0.47; all P < 0.001, respectively). Moreover, HGI (area under the curve [AUC]: 0.69; 95% CI: 0.65-0.72) and peak RPP (AUC: 0.71; 95% CI: 0.68-0.74) were comparable to the standard peak Vo2 (AUC: 0.70; 95% CI: 0.66-0.73; P for comparison = 0.607 and 0.393, respectively) for primary outcome discrimination.

CONCLUSIONS

HGI and peak RPP show good correlation with peak Vo2 in terms of prognostication and outcome discrimination in patients with HFrEF and may serve as suitable alternatives to CPET-derived prognostic variables.

The potential of herbal drugs to treat heart failure: The roles of Sirt1/AMPK

Heart failure (HF) is a highly morbid syndrome that seriously affects the physical and mental health of patients and generates an enormous socio-economic burden. In addition to cardiac myocyte oxidative stress and apoptosis, which are considered mechanisms for the development of HF, alterations in cardiac energy metabolism and pathological autophagy also contribute to cardiac abnormalities and ultimately HF. Silent information regulator 1 (Sirt1) and adenosine monophosphate-activated protein kinase (AMPK) are nicotinamide adenine dinucleotide (NAD+)-dependent deacetylases and phosphorylated kinases, respectively. They play similar roles in regulating some pathological processes of the heart through regulating targets such as peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α), protein 38 mitogen-activated protein kinase (p38 MAPK), peroxisome proliferator-activated receptors (PPARs), and mammalian target of rapamycin (mTOR). We summarized the synergistic effects of Sirt1 and AMPK in the heart, and listed the traditional Chinese medicine (TCM) that exhibit cardioprotective properties by modulating the Sirt1/AMPK pathway, to provide a basis for the development of Sirt1/AMPK activators or inhibitors for the treatment of HF and other cardiovascular diseases (CVDs).

Improving Respiratory Muscle Strength and Overall Function in Patients With Cardiovascular Disease Through Rehabilitation Hospitals

Background

The prevalence of respiratory sarcopenia and its effect on respiratory muscle strength (RMS) in patients with cardiovascular disease (CVD), who are transferred to a convalescent rehabilitation hospital after acute care and require continuous cardiac rehabilitation (CR), is currently unclear. This study aimed to assess changes in RMS, physical function, and activities of daily living (ADL) before and after CR performed in a rehabilitation hospital.

Methods

Of 50 consecutive patients transferred to a rehabilitation hospital for ongoing CR, 30 fulfilled the inclusion criteria. Maximal inspiratory and expiratory pressures (MIP and MEP, respectively) were measured at transfer, and patients with decreased RMS were diagnosed with respiratory sarcopenia. RMS, physical function, exercise tolerance, ADL ability, and health-related quality of life (HR-QoL) were measured and compared at transfer and discharge.

Results

The prevalence of respiratory sarcopenia at the time of transfer to the rehabilitation hospital was 93.3%. RMS assessments at transfer and discharge demonstrated significant improvements in %MIP (from 46.3±26.1% to 63.6±33.7%) and %MEP (from 44.8±17.3% to 56.6±21.8%). Short physical performance battery, gait speed, handgrip strength, and knee extension muscle strength significantly improved, along with significant prolongation of 6-min walking distance as a measure of exercise tolerance. ADL assessment using the functional independence measure revealed significant improvement, as did HR-QoL assessed according to the five-dimension, five-level, EuroQoL instrument, following CR.

Conclusions

Although respiratory sarcopenia was highly prevalent among patients with CVD who required transfer to a rehabilitation hospital after acute care, continuous CR significantly improved RMS, ADL, physical function, and exercise tolerance. These findings support the continued expansion of CR, particularly in dedicated rehabilitation hospitals.

Time of eating and mortality in U.S. adults with heart failure: Analyses of the National Health and Nutrition Examination Survey 2003-2018

BACKGROUND AND AIMS

Promising associations have been demonstrated between delayed last eating occasion and cardiorespiratory fitness in adults with heart failure (HF), however, it is unknown if time of eating is associated with clinical endpoints such as mortality. This study aimed to examine associations between time of eating variables and all-cause and cardiovascular mortality in the National Health and Nutrition Examination Survey (NHANES).

METHODS AND RESULTS

Participants self-disclosed HF diagnosis. Two dietary recalls were obtained and categorical variables were created based on mean time of first eating occasion (8:31 AM), last eating occasion (7:33 PM) and eating window (11.02 h). Mortality was obtained through linkage to the National Death Index. Covariate-adjusted Cox proportional hazard regression models were created examining the association between time of eating and mortality. Participants (n = 991) were 68 (95 % CI 67-69) years of age, 52.6 (95 % CI 49.0-56.3)% men and had a body mass index of 32.5 (95 % CI 31.8-33.2) kg/m2 with follow up time of 68.9 (95 % CI 64.8-72.9) person-months. When models were adjusted for time of eating variables and all other covariates, extending the eating window beyond 11.02 h was associated with decreased risk of cardiovascular (HR 0.36 [95 % CI 0.16-0.81]), but not all-cause mortality. Time of first and last eating occasions were not associated with mortality.

CONCLUSIONS

In adults with HF, an extended eating window is associated with reduced risk for cardiovascular mortality. Randomized controlled trials should examine if extending the eating window can improve prognostic indicators such as cardiorespiratory fitness in this population.

Update on obesity, the obesity paradox, and obesity management in heart failure

Obesity is a major public health challenge worldwide. It is costly, predisposes to many cardiovascular (CV) diseases (CVD), is increasing at an alarming rate, and disproportionately affects people of low-socioeconomic status. It has a myriad of deleterious effects on the body, particularly on the CV system. Obesity is a major risk factor for heart failure (HF) and highly prevalent in this population, particularly in those with HF with preserved ejection fraction (HFpEF), to the extent that an obesity HFpEF phenotype has been proposed in the literature. However, once HF is developed, an obesity paradox exists where those with obesity have better short- and mid-term survival than normal or underweight individuals, despite a greater risk for hospitalizations. It may be argued that excess energy reserve, younger patient population, higher tolerability of HF therapy and better nutritional status may account for at least part of the obesity paradox on survival. Furthermore, body mass index (BMI) may not be an accurate measure of body composition, especially in HF, where there is an excess volume status. BMI also fails to delineate fat-free mass and its components, which is a better predictor of functional capacity and cardiorespiratory fitness (CRF), which particularly is increasingly being recognized as a risk modifier in both healthy individuals and in persons with comorbidities, particularly in HF. Notably, when CRF is accounted for, the obesity paradox disappears, suggesting that improving CRF might represent a therapeutic target with greater importance than changes in body weight in the setting of HF. In this narrative review, we discuss the current trends in obesity, the causal link between obesity and HF, an update on the obesity paradox, and a description of the major flaws of BMI in this population. We also present an overview of the latest in HF therapy, weight loss, CRF, and the application of these therapeutic approaches in patients with HF and concomitant obesity.

Assessment of health-related quality of life in patients with Chagas cardiomyopathy using Minnesota living with heart failure questionnaire: A validation study

OBJECTIVE

Chagas cardiomyopathy (ChC) is the most severe clinical form of Chagas disease and, in association with psychosocial factors, can compromise the health-related quality of life (HRQoL) of affected patients. To date, there is no specific instrument to assess the HRQoL of these patients, and the Minnesota Living with Heart Failure Questionnaire (MLwHFQ), specific for heart failure, is being used both in research and current clinical practice. Therefore, we aimed to verify the validity of the MLwHFQ in the assessment of HRQoL of patients with ChC.

METHODS

Fifty patients with ChC (50.6 ± 10.1 years, NYHA I-III) were evaluated. The MLwHFQ, Short-Form of Health Survey (SF-36), Beck Depression Inventory (BDI), and Human Activity Profile (HAP) were applied. All patients underwent echocardiography and Cardiopulmonary Exercise Testing (CPET).

RESULTS

The MLwHFQ score correlated with almost all SF-36 domains (with r-value ranging from -0.38 to -0.69), except pain (p = 0.118). The MLwHFQ score also correlated with the BDI score (r = 0.748; p < 0.001), HAP score (r = -0.558; p = 0.001), peak oxygen uptake (r = -0.352; p = 0.01), and left ventricular ejection fraction (r = -0.329; p = 0.021). There was no significant difference in the score found on the MLwHFQ among NYHA classes (p = 0.101), as well as between patients with systolic dysfunction (n = 30) and preserved cardiac function (n = 20) (p = 0.058). Similarly, there was no significant difference in the score found on the physical (p = 0.423) and mental (p = 0.858) components of SF-36 between patients with systolic dysfunction and preserved cardiac function (p = 0.271 and p = 0.609, respectively). There was also no difference in the mental component of SF-36 among NYHA classes (p = 0.673). However, the HRQoL using the physical component of SF-36 was worse in advanced NYHA classes (p = 0.014).

CONCLUSION

MLwHF correlated with most SF-36 HRQoL domains, depressive symptoms, physical activity, and systolic function and seems to be valid in assessing the HRQoL of ChC patients.

Role of exercise therapy and cardiac rehabilitation in heart failure

Heart failure (HF) is a common cause of hospitalization and death, and the hallmark symptoms of HF, including dyspnea, fatigue, and exercise intolerance, contribute to poor patient quality of life (QoL). Cardiac rehabilitation (CR) is a comprehensive disease management program incorporating exercise training, cardiovascular risk factor management, and psychosocial support. CR has been demonstrated to effectively improve patient functional status and QoL among patients with HF. However, CR participation among patients with HF is poor. This review details the mechanisms of dyspnea and exercise intolerance among patients with HF, the physiologic and clinical improvements observed with CR, and the key components of a CR program for patients with HF. Furthermore, unmet needs and future strategies to improve patient participation and engagement in CR for HF are reviewed.

Molecular mechanisms underlying sarcopenia in heart failure

The loss of skeletal muscle, also known as sarcopenia, is an aging-associated muscle disorder that is disproportionately present in heart failure (HF) patients. HF patients with sarcopenia have poor outcomes compared to the overall HF patient population. The prevalence of sarcopenia in HF is only expected to grow as the global population ages, and novel treatment strategies are needed to improve outcomes in this cohort. Multiple mechanistic pathways have emerged that may explain the increased prevalence of sarcopenia in the HF population, and a better understanding of these pathways may lead to the development of therapies to prevent muscle loss. This review article aims to explore the molecular mechanisms linking sarcopenia and HF, and to discuss treatment strategies aimed at addressing such molecular signals.

Right ventricular outflow tract diameter change with exercise: a prospective exercise echocardiography and invasive CPET study

While cardiac output reserve with exercise predicts outcomes in cardiac and pulmonary vascular disease, precise quantification of exercise cardiac output requires invasive cardiopulmonary testing (iCPET). To improve the accuracy of cardiac output reserve estimation with transthoracic echocardiography (TTE), this prospective study aims to define changes in right ventricular outflow tract diameter (RVOTd) with exercise and its relationship with invasively measured haemodynamics. Twenty subjects underwent simultaneous TTE and iCPET, with data collected at rest, leg-raise, 25 W, 50 W (n = 16), 75 W (n = 14), and 100 W (n = 6). This was followed by a second exercise study with real-time RV pressure-volume loops at similar stages (except leg-raise). The overall cohort included heart failure with preserved ejection fraction (n = 12), pulmonary arterial hypertension (n = 5), and non-cardiac dyspnoea (n = 3). RVOTd was reverse engineered from the TTE-derived RVOT velocity time integral (VTI) and iCPET-derived stroke volume, using the formula: Fick stroke volume = RVOT VTI × RVOT area (wherein RVOT area = π × [RVOTd/2]2). RVOTd increased by nearly 3-4% at every 25 W increment. Using linear regression models, where each subject is treated as a categorical variable and adjusting for subject intercept, RVOTd was correlated with haemodynamic variables (cardiac output, heart rate, pulmonary artery and RV pressures). Of all the predictor haemodynamic variables, cardiac output had the highest r2 model fit (adjusted r2 = 0.68), with a unit increase in cardiac output associated with a 0.0678 increase in RVOTd (P < 0.001). Our findings indicate that RVOTd increases by 3-4% with every 25 W increment, predominantly correlated with cardiac output augmentation. These results can improve the accuracy of cardiac output reserve estimation by adjusting for RVOTd with graded exercise during non-invasive CPET and echocardiogram. However, future studies are needed to define these relationships for left ventricular outflow tract diameter.

Consensus document on palliative care in cardiorenal patients

There is an unmet need to create consensus documents on the management of cardiorenal patients since, due to the aging of the population and the rise of both pathologies, these patients are becoming more prevalent in daily clinical practice. Chronic kidney disease coexists in up to 40%-50% of patients with chronic heart failure cases. There have yet to be consensus documents on how to approach palliative care in cardiorenal patients. There are guidelines for patients with heart failure and chronic kidney disease separately, but they do not specifically address patients with concomitant heart failure and kidney disease. For this reason, our document includes experts from different specialties, who will not only address the justification of palliative care in cardiorenal patients but also how to identify this patient profile, the shared planning of their care, as well as knowledge of their trajectory and the palliative patient management both in the drugs that will help us control symptoms and in advanced measures. Dialysis and its different types will also be addressed, as palliative measures and when the decision to continue or not perform them could be considered. Finally, the psychosocial approach and adapted pharmacotherapy will be discussed.

Research trends and hotspots in exercise rehabilitation for coronary heart disease: A bibliometric analysis

Exercise rehabilitation can improve the prognosis of patients with coronary heart disease. However, a bibliometric analysis of the global exercise rehabilitation for coronary heart disease (CHD) research topic is lacking. This study investigated the development trends and research hotspots in the field of coronary heart disease and exercise rehabilitation. CiteSpace software was used to analyze the literature on exercise therapy for CHD in the Web of Science Core Collection database. We analyzed the data of countries/institutions, journals, authors, keywords, and cited references. A total of 3485 peer-reviewed papers were found, and the number of publications on the topic has steadily increased. The most productive country is the USA (1125), followed by China (477) and England (399). The top 3 active academic institutions are Research Libraries UK (RLUK) (236), Harvard University (152), and the University of California System (118). The most commonly cited journals are Circulation (2596), The most commonly cited references are "Exercise-based cardiac rehabilitation for coronary heart disease" (75), Lavie CJ had published the most papers (48). World Health Organization was the most influential author (334 citations). The research frontier trends in this field are body composition, participation, and function. Research on the effects of physical activity or exercise on patients with CHD is a focus of continuous exploration in this field. This study provides a new scientific perspective for exercise rehabilitation and CHD research and gives researchers valuable information for detecting the current research status, hotspots, and emerging trends for further research.

Inspiratory Muscle Strength in Chagas Cardiomyopathy: A Systematic Scoping Review

The increase in inflammatory markers associated with persistent chronic fibrosing myocarditis, a characteristic of chronic Chagas disease, can result in a reduction in inspiratory muscle strength (IMS) in Chagas cardiomyopathy (CC). However, literature in this field is still scarce. This review aimed to map and summarize the evidence regarding IMS in patients with CC. The inclusion criteria included reports with adult participants with a CC diagnosis, with or without heart failure (HF). The core concept examined was the maximum inspiratory pressure evaluated in the untrained and trained groups in the pre-training period. The context was open, including but not limited to hospitals and health centers. Two authors independently identified eligible studies and extracted the data. Descriptive synthesis was used as the primary strategy for analyzing the results. Nine studies (five clinical trials, three cross-sectional, and one cohort) were included. The CC classification differed among the studies, with no mention of HF in five and no CC staging specification in six. IMS was assessed using a manovacuometer, and only six studies analyzed and interpreted the data concerning the predicted values. The CC population with HF appeared to have impaired IMS. All studies involved only Brazilian volunteers. In conclusion, randomized clinical trials evaluating IMS and the effects of inspiratory muscle training need to be conducted to better understand the prevalence and risk of inspiratory muscle weakness in the CC population, as well as the effects of training. Such studies should be conducted at different stages of CC in different populations and countries.

What frail, older patients talk about when they talk about self-care-a qualitative study in heart failure care

BACKGROUND

Self-care plays a crucial role in the management of heart failure (HF) and is especially important for older patients who are frail. However, there is limited knowledge about how frail, older patients with HF perceive and experience self-care. Therefore, the aim of this study was to describe the experiences of self-care among frail, older patients with HF.

METHODS

A qualitative descriptive design with semi-structured interviews with frail, older patients diagnosed with HF (n = 19; median age 82 years). Thematic analysis, guided by Braun and Clarke, was used to analyse the data.

RESULTS

Two main themes emerged from the analysis: 1) "To maintain my health," encompassing various aspects such as hygiene practices, engaging in physical activity, medication adherence, following a healthy diet, and ensuring adequate rest; and 2) "To maintain my well-being and happiness," highlighting the importance of hobbies, maintaining independence, participating in social activities, and creating a supportive environment.

CONCLUSION

This study provides valuable insights into the perspectives of frail, older patients with HF regarding self-care. It was observed that older patients often associate self-care with general well-being, hygiene, and happiness. Clear communication between healthcare providers and patients is essential to align different perspectives on self-care and ensure that self-care plans are tailored to individual needs. Moreover, addressing the emotional well-being and happiness of patients should be prioritized, as these factors play a significant role in promoting self-care adherence.

Skeletal muscle quality, measured via phase angle, and cardiorespiratory fitness in patients with obesity and heart failure with preserved ejection fraction

OBJECTIVES

Cardiorespiratory fitness (CRF) is influenced by body composition quantity and quality in heart failure with preserved ejection fraction (HFpEF) and obesity. Bioelectrical impedance analysis (BIA) provides a noninvasive quantitative and qualitative body composition assessment. The aim of this study was to determine the role of phase angle (PhA), a BIA-measure of skeletal muscle quality and body cell mass, on CRF in patients with obesity and HFpEF.

METHODS

Fifty-nine consecutive outpatients with HFpEF underwent cardiopulmonary exercise testing to measure CRF. Single-frequency segmental BIA was used to measure PhA and body composition quantity. Resting Doppler echocardiography and biomarkers were measured to assess cardiac function and systemic inflammation.

RESULTS

Compared with patients with lower PhA, patients with higher PhA (above mean 5.8°) presented a greater absolute peak oxygen consumption (VO2; 1.83 [1.3-2.1] versus 1.39 [1.1-1.6] L/min, P = 0.003), VO2 peak adjusted for body weight (17.5 [12.3-18.1] versus 13.3 [12.7-15.2] mL/kg/min, P = 0.040), and a lower edema index (48.7 [2.9] versus 51.4% [2.7], P < 0.001) and N-terminal pro-B-type natriuretic peptide (NT-proBNP; 64 [50-121] versus 183 [68-343.5] pg/dL, P < 0.001). In the overall sample, PhA was correlated with absolute VO2 peak (r = 0.468, P < 0.001), VO2 peak adjusted for body weight (r = 0.368, P = 0.004), VO2 peak adjusted for fat-free mass (r = 0.315, P = 0.015), edema index (r = -0.508, P < 0.001), and NT-proBNP (r = -0.579, P < 0.001). PhA remained a significant predictor for CRF even after adjustment for potential confounders and HFpEF severity.

CONCLUSION

In patients with obesity and HFpEF, a greater PhA is an independent predictor for favorable CRF.

Low-dose exercise protects the heart against established myocardial infarction via IGF-1-upregulated CTRP9 in male mice

Regular exercise is recommended as an important component of therapy for cardiovascular diseases in clinical practice. However, there are still major challenges in prescribing an optimized exercise regimen to individual patients with established cardiac disease. Here, we tested the effects of different exercise doses on cardiac function in mice with established myocardial infarction (MI). Exercise was introduced to mice with MI after 4 weeks of surgery. Low-dose exercise (15 min/day for 8 weeks) improved mortality and cardiac function by increasing 44.39% of ejection fractions while inhibiting fibrosis by decreasing 37.74% of distant region. Unlike higher doses of exercise, low-dose exercise consecutively upregulated cardiac expression of C1q complement/tumor necrosis factor-associated protein 9 (CTRP9) during exercise (>1.5-fold). Cardiac-specific knockdown of CTRP9 abolished the protective effects of low-dose exercise against established MI, while cardiac-specific overexpression of CTRP9 protected the heart against established MI. Mechanistically, low-dose exercise upregulated the transcription factor nuclear receptor subfamily 2 group F member 2 by increasing circulating insulin-like growth factor 1 (IGF-1), therefore, upregulating cardiac CTRP9 expression. These results suggest that low-dose exercise protects the heart against established MI via IGF-1-upregulated CTRP9 and may contribute to the development of optimized exercise prescriptions for patients with MI.

Anodal transcranial direct current stimulation associated with aerobic exercise on the functional and physical capacity of patients with heart failure with reduced ejection fraction: ELETRIC study protocol

BACKGROUND

The hallmark symptom of heart failure (HF) is severe exercise intolerance. Fortunately, accumulated evidence suggests that exercise programs improve physical performance, enhance autonomy in daily activities and quality of life, and reduce cardiovascular and other hospitalizations. Recently, experimental studies have explored the application of non-invasive brain stimulation techniques, especially transcranial direct current stimulation (tDCS), aiming to improve physical performance due to its ability to modulate brain functioning. The primary objective of the present study is to evaluate the effects of anodal tDCS associated with aerobic exercise on the functional capacity of patients with HF with reduced ejection fraction (HFrEF). Secondary objectives are to compare the effects of tDCS associated with aerobic exercise vs. sham-tDCS associated with aerobic exercise on cardiopulmonary exercise capacity; inflammatory cytokines; and quality of life.

METHODS

This is a two-arm, prospectively registered, randomized trial with concealed allocation, double-blind, and intention-to-treat analysis. Forty-four patients with HFrEF will be recruited. The experimental group will undertake 25-30 min aerobic exercise training associated with tDCS, for 4 weeks. The control group will undergo the same aerobic exercise training, but with sham-tDCS. The primary outcome will be functional performance by the 6-min walk test. Secondary outcomes will include cardiopulmonary exercise capacity, inflammatory cytokines, and quality of life. Outcomes will be collected by a researcher blinded to group allocation at baseline (T0) and after 4 weeks of intervention (T1).

DISCUSSION

Although previous studies have investigated the combined effect of tDCS on T3 area and physical performance and have suggested that tDCS could have reduced ratings of perceived exertion by affecting the activity of the insular cortex, and therefore increase exercise tolerance, this study is the first to evaluate the effects of the addition of anodal tDCS to aerobic exercise training for improving physical and functional performance, decreasing the perceived exertion, altering the quantification of inflammatory cytokines, and improving the subclinical values of the cardiopulmonary test in patients with HFrEF, which could result in an important advance in cardiac rehabilitation for patients with chronic HF.

TRIAL REGISTRATION

Brazilian Registry of Clinical Trials (ReBEC) RBR-10w787j6. Registered on 25 April 2023. https://ensaiosclinicos.gov.br/pesquisador.

Does COVID-19 impair V̇o2peak in patients with cardiorespiratory disease? Insight from cardiopulmonary responses to maximal exercise pre- and post-illness

Reduced exercise capacity has been suggested as a cardinal sequela of COVID-19. However, only cross-sectional approaches that either do not consider individuals with concomitant cardiorespiratory disease or account for exercise capacity before infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) support this assumption. Is reduced exercise capacity a sequela of SARS-CoV-2 infection in patients with concomitant cardiorespiratory disease? We retrospectively reviewed cardiopulmonary exercise testing (CPET) data collected across three hospitals between October 2018 and March 2022. Forty-two patients who completed a CPET before and after COVID-19 and 25 patients who performed two separate CPETs but did not contract COVID-19 (CTL) were included. Within each patient, the same test protocol was performed at the first and second CPETs. The time between CPETs was similar between the groups (COVID-19 489 ± 534 vs. CTL 534 ± 257 days, P = 0.662). The COVID-19 group performed the CPETs 312 ± 232 days before and 176 ± 110 days after infection. Exercise time, peak heart rate, peak systolic pressure, oxygen uptake (V̇o2) at anaerobic threshold, peak ventilation, and ventilatory efficiency were not different between the CPETs in both groups. Peak V̇o2 was reduced from before to after SARS-CoV-2 infection. However, the change in V̇o2peak from the first to the second CPET was not different between COVID-19 vs. CTL. Accounting for V̇o2peak before COVID-19 and including a group of control patients, we find limited evidence for reduced exercise capacity as a sequela of SARS-CoV-2 infection in patients with concomitant cardiorespiratory disease.NEW & NOTEWORTHY There is accumulating evidence that reduced exercise capacity is, or can be, an outcome following COVID-19. However, evidence to date relies upon cross-sectional approaches that either do not consider patients with concomitant cardiorespiratory disease or account for pre-infection exercise capacity data. Accounting for V̇o2peak before COVID-19 and including a group of control patients, we find limited evidence for reduced exercise capacity as a sequela of SARS-CoV-2 infection in patients with concomitant cardiorespiratory disease.

Obesity-Related Biomarkers Are Associated With Exercise Intolerance and HFpEF

BACKGROUND

Obesity and adiposity are associated with an increased risk of heart failure with preserved ejection fraction (HFpEF); yet, specific underlying mechanisms remain unclear. We sought to examine the association of obesity-related biomarkers including adipokines (leptin, resistin, adiponectin), inflammatory markers (CRP [C-reactive protein], IL-6 [interleukin-6]), and insulin resistance (HOMA-IR) with HFpEF status, exercise capacity, and cardiovascular outcomes.

METHODS

We studied 509 consecutive patients with left ventricular ejection fraction ≥50% and chronic dyspnea, who underwent clinically indicated cardiopulmonary exercise test with invasive hemodynamic monitoring between 2006 and 2017. We defined HFpEF based on the presence of elevated left ventricular filling pressures at rest or during exercise. Fasting blood samples collected at the time of the cardiopulmonary exercise test were used to assay obesity-related biomarkers. We examined the association of log-transformed biomarkers with HFpEF status and exercise traits using multivariable-adjusted logistic regression models.

RESULTS

We observed associations of obesity-related biomarkers with measures of impaired exercise capacity including peak VO2 (P≤0.002 for all biomarkers). The largest effect size was seen with leptin, where a 1-SD higher leptin was associated with a 2.35 mL/kg per min lower peak VO2 (β, -2.35±0.19; P<0.001). In addition, specific biomarkers were associated with distinct measures of exercise reserve including blood pressure (homeostatic model assessment of insulin resistance, leptin, adiponectin; P≤0.002 for all), and chronotropic response (CRP, IL-6, homeostatic model assessment of insulin resistance, leptin, and resistin; P<0.05 for all). Our findings suggest that among the obesity-related biomarkers studied, higher levels of leptin and CRP are independently associated with increased odds of HFpEF, with odds ratios of 1.36 (95% CI, 1.09-1.70) and 1.25 (95% CI, 1.03-1.52), respectively.

CONCLUSIONS

Specific obesity-related pathways including inflammation, adipokine signaling, and insulin resistance may underlie the association of obesity with HFpEF and exercise intolerance.

Practical guidelines for exercise prescription in patients with chronic heart failure

Chronic heart failure (HF) is a major cause of morbidity, mortality, disability, and health care costs. A hallmark feature of HF is severe exercise intolerance, which is multifactorial and stems from central and peripheral pathophysiological mechanisms. Exercise training is internationally recognized as a Class 1 recommendation for patients with HF, regardless of whether ejection fraction is reduced or preserved. Optimal exercise prescription has been shown to enhance exercise capacity, improve quality of life, and reduce hospitalizations and mortality in patients with HF. This article will review the rationale and current recommendations for aerobic training, resistance training, and inspiratory muscle training in patients with HF. Furthermore, the review provides practical guidelines for optimizing exercise prescription according to the principles of frequency, intensity, time (duration), type, volume, and progression. Finally, the review addresses common clinical considerations and strategies when prescribing exercise in patients with HF, including considerations for medications, implantable devices, exercise-induced ischemia, and/or frailty.

Effects of high intensity interval-based inspiratory muscle training in patients with heart failure: A single-blind randomized controlled trial

BACKGROUND

Given the promising effects of inspiratory muscle training (IMT), determining the most appropriate IMT protocol will optimize the training benefits.

OBJECTIVES

The objective of this study was to determine the effects of high intensity interval-based inspiratory muscle training (H-IMT) on cardiovascular, pulmonary, physical, and psychosocial functions in patients with heart failure and reduced ejection fraction (HFrEF).

METHODS

Thirty-four patients with HFrEF were randomly assigned to the H-IMT or control group for 3 days/week, 8 weeks training period. The H-IMT group performed IMT at least 70% of the maximal inspiratory pressure, whereas the control group performed unloaded IMT. Each session occurred 7 sets with a total of 21 min consisting of 2-min training and 1-min interval. Heart rate variability (HRV), arterial stiffness, respiratory muscle strength and endurance, diaphragm thickness, quadriceps strength, functional capacity, frailty, dyspnea, fatigue, disease-specific health-related quality of life (HRQoL), and generic HRQoL were evaluated at baseline and after 8 weeks training period by blinded assessors.

RESULTS

Statistically significant between-group differences were observed in the time domain parameters of HRV, arterial stiffness, inspiratory and quadriceps muscle strength, respiratory muscle endurance, diaphragm thickness, functional capacity, frailty, dyspnea, fatigue, and disease-specific HRQoL in favor of the H-IMT group (p<0.05).

CONCLUSIONS

H-IMT is an effective protocol for improving cardiac autonomic function, arterial stiffness, inspiratory and quadriceps muscle strength, respiratory muscle endurance, diaphragm thickness, functional capacity, frailty, dyspnea, fatigue, and disease-specific quality of life in patients with HFrEF.

CLINICAL TRIAL REGISTRATION

NCT04839211.

Exercise Rehabilitation for People With End-Stage Kidney Disease: Who Will Fill the Gaps?

Exercise rehabilitation is a well established therapy for reducing morbidity and mortality and improving quality of life and function across chronic conditions. People with dialysis-dependent kidney failure have a high burden of comorbidity and symptoms, commonly characterised as fatigue, dyspnoea, and the inability to complete daily activities. Despite more than 30 years of exercise research in people with kidney disease and its established benefit in other chronic diseases, exercise programs are rare in kidney care and are not incorporated into routine management at any stage. In this review, we describe the mechanisms contributing to exercise intolerance in those with end-stage kidney disease and outline the role of exercise rehabilitation in addressing the major challenges to kidney care: cardiovascular disease, symptom burden, and physical frailty. We also draw on existing models of exercise rehabilitation from other chronic conditions to inform the way forward and challenge the status quo of exercise rehabilitation in both practice and research.

Quantitative Evidence of the effect of Baduanjin exercise on quality of life and cardiac function in adults with chronic heart failure

BACKGROUND

This study aimed to assess the effects of Baduanjin exercise on the quality of life (QoL), cardiac function, and maximal oxygen consumption (VO2max) in patients with chronic heart failure (CHF).

METHODS

A systematic search of relevant literature published from inception until February 2023 was performed in the Scopus, PubMed, MEDLINE, CINAHL, Cochrane Library, SPORTDiscus, and China National Knowledge Infrastructure databases. We included randomized controlled trials (RCTs) that examined the effects of Baduanjin exercise on QoL (Minnesota Living with Heart Failure Questionnaire [MLHFQ]), cardiac function (N-terminal B-type natriuretic peptide [NT-Pro BNP] and left ventricular ejection fraction [LVEF]), and VO2max in patients with CHF.

RESULTS

Fifteen studies (1180 participants) were included in this analysis. The synthesized results suggested that Baduanjin exercise contributed to significant improvements in the MLHFQ scores (standard mean difference [SMD] = 1.10, 95% confidence interval [CI]: 0.81 to 1.39, p < 0.001), NT-Pro BNP levels (SMD = 0.62, 95% CI: 0.31 to 0.93, p < 0.01), LVEF (SMD = 0.53, 95% CI: 0.18 to 0.88, p < 0.01), and VO2max (SMD = 0.92, 95% CI: 0.24 to 1.60, p < 0.001) compared with the results of the control groups. Subgroup analyses revealed that engaging in Baduanjin exercise 5-7 times per week was more effective in improving the MLHFQ score compared with 3-4 times per week (p = 0.04).

CONCLUSION

Evidence from the meta-analysis support the beneficial effects of Baduanjin exercise on the QoL, cardiac function, and VO2max in patients with CHFin China. For optimal QoL improvements, it is recommended to engage in Baduanjin exercise 5-7 times per week for 30-60 min, over a duration of at least 8 weeks. In terms of NT-Pro BNP, Baduanjin exercise sessions of 30-60 min, 2-7 times per week, for a minimum of 8 weeks are recommended.

Empagliflozin induces the transcriptional program for nutrient homeostasis in skeletal muscle in normal mice

Sodium-glucose cotransporter 2 inhibitors (SGLT2i) improve heart failure (HF) outcomes across a range of patient characteristics. A hypothesis that SGLT2i induce metabolic change similar to fasting has recently been proposed to explain their profound clinical benefits. However, it remains unclear whether SGLT2i primarily induce this change in physiological settings. Here, we demonstrate that empagliflozin administration under ad libitum feeding did not cause weight loss but did increase transcripts of the key nutrient sensors, AMP-activated protein kinase and nicotinamide phosphoribosyltransferase, and the master regulator of mitochondrial gene expression, PGC-1α, in quadriceps muscle in healthy mice. Expression of these genes correlated with that of PPARα and PPARδ target genes related to mitochondrial metabolism and oxidative stress response, and also correlated with serum ketone body β-hydroxybutyrate. These results were not observed in the heart. Collectively, this study revealed that empagliflozin activates transcriptional programs critical for sensing and adaptation to nutrient availability intrinsic to skeletal muscle rather than the heart even in normocaloric condition. As activation of PGC-1α is sufficient for metabolic switch from fatigable, glycolytic metabolism toward fatigue-resistant, oxidative mechanism in skeletal muscle myofibers, our findings may partly explain the improvement of exercise tolerance in patients with HF receiving empagliflozin.

Right Ventricular Function and Exercise Tolerance in Patients with ST-Elevation Myocardial Infarction

BACKGROUND

Following ST-segment elevation myocardial infarction (STEMI), patients with cardiac dysfunction have limitations in performing physical activity. Right ventricular (RV) function is a determinant in improving functional capacity, and cardiac rehabilitation (CR) is essential for this patient cohort.

OBJECTIVE

To evaluate the association of RV function with exercise tolerance after a CR program in patients with STEMI.

METHODS

Retrospective cohort study in patients with STEMI from January to December 2019. They underwent an echocardiographic assessment of RV function before a 16-session CR program. A cardiopulmonary exercise (CPX) testing was performed before and after the CR program. We analyzed whether RV function measured before CR was significantly associated with exercise tolerance before and after the CR program and the degree of improvement. Comorbidity, demographic and anatomic variables were documented. A p-value < 0.05 was considered statistically significant.

RESULTS

A total of 109 patients were included. Of all, 3.7% had global RV dysfunction, 10.1% had radial RV dysfunction, and 11% had longitudinal RV dysfunction. An association between radial or longitudinal RV dysfunction and the absence of improvement in cardiorespiratory fitness (> 1 peak VO2equivalents) was observed (p = 0.028, p = 0.008, respectively). A significant correlation was observed between longitudinal RV dysfunction with initial peak VO2equivalents (pVO2eq) (p = 0.046), final pVO2eq (p = 0.003), and difference in pVO2eq (p = 0.009). A correlation was also identified between global RV dysfunction and the initial pVO2eq (p = 0.045), final pVO2eq (p = 0.012), and difference in pVO2eq (p = 0.032).

CONCLUSIONS

RV dysfunction is associated with a lower capacity to exercise; CR programs can be extended or modified in these patients.

Contribution of hemoglobin concentration to cardiorespiratory fitness in black African American patients with recently decompensated heart failure and reduced ejection fraction

BACKGROUND

Previous studies have shown that patients with heart failure with reduced ejection fraction (HFrEF) and anemia have reduced peak oxygen consumption (VO2). Black or African American (B-AA) patients have a higher prevalence of anemia and are underrepresented in clinical studies of HFrEF. The aim of this study was to determine the contribution of hemoglobin to peak VO2 in B-AA patients recently hospitalized for acute decompensated HFrEF.

METHODS

We analyzed cardiopulmonary exercise testing (CPX) data measured within two weeks of discharge for acute decompensated HF in B-AA patients with HFrEF (left ventricular ejection fraction [LVEF] ≤40%) without severe anemia (Hb<8 g/dL). Blood samples were collected prior to CPX. Data are reported as median [interquartile range] and compared between groups with the Mann-Whitney, Chi-Square, and Spearman's rank tests.

RESULTS

We included 81 patients; 27 (33%) women, 57 [27-79] years of age, Body Mass Index of 33 [15-55] kg/m2 and LVEF of 30 [23-36] %. Hemoglobin ranged between 9.1 to 18.1 g/dL (median= 13.3 [11.9-14.5] g/dL); 26 (32%) were considered to have anemia based on a Hb concentration of males <13 g/dL and females <12 g/dL. Peak VO2 was lower in patients with anemia (11.8 [10.0-14.2] vs. 14.1 [10.6-17.0] mL·kg-1·min-1; P=0.010) with a significant correlation between peak VO2 and hemoglobin concentration (R=+0.455; P<0.001).

CONCLUSIONS

Anemia is prevalent among B-AA patients with recently decompensated HFrEF and appears to be a significant contributor to reductions in peak VO2.

Functional training improves peak oxygen consumption and quality of life of individuals with heart failure: a randomized clinical trial

BACKGROUND

Functional training may be an effective non-pharmacological therapy for heart failure (HF). This study aimed to compare the effects of functional training with strength training on peak VO₂ and quality of life in individuals with HF.

METHODS

A randomized, parallel-design and examiner-blinded controlled clinical trial with concealed allocation, intention-to-treat and per-protocol analyses. Twenty-seven participants with chronic HF were randomly allocated to functional or strength training group, to perform a 12-week physical training, three times per week, totalizing 36 sessions. Primary outcomes were the difference on peak VO₂ and quality of life assessed by cardiopulmonary exercise testing and Minnesota Living with Heart Failure Questionnaire, respectively. Secondary outcomes included functionality assessed by the Duke Activity Status Index and gait speed test, peripheral and inspiratory muscular strength, assessed by hand grip and manovacuometry testing, respectively, endothelial function by brachial artery flow-mediated dilation, and lean body mass by arm muscle circumference.

RESULTS

Participants were aged 60 ± 7 years, with left ventricular ejection fraction 29 ± 8.5%. The functional and strength training groups showed the following results, respectively: peak VO₂ increased by 1.4 ± 3.2 (16.9 ± 2.9 to 18.6 ± 4.8 mL.kg^-1.min^-1; p time = 0.011) and 1.5 ± 2.5 mL.kg^-1.min^-1 (16.8 ± 4.0 to 18.6 ± 5.5 mL.kg^-1.min^-1; p time = 0.011), and quality of life score decreased by 14 ± 15 (25.8 ± 14.8 to 10.3 ± 7.8 points; p time = 0.001) and 12 ± 28 points (33.8 ± 23.8 to 19.0 ± 15.1 points; p time = 0.001), but no difference was observed between groups (peak VO₂: p interaction = 0.921 and quality of life: p interaction = 0.921). The functional and strength training increased the activity status index by 6.5 ± 12 and 5.2 ± 13 points (p time = 0.001), respectively, and gait speed by 0.2 ± 0.3 m/s (p  time = 0.002) in both groups.

CONCLUSIONS

Functional and strength training are equally effective in improving peak VO₂, quality of life, and functionality in individuals with HF. These findings suggest that functional training may be a promising and innovative exercise-based strategy to treat HF.

TRIAL REGISTRATION

NCT03321682. Registered date: 26/10/2017.

Wildland fire, air pollution and cardiovascular health: is it time to focus on the microvasculature as a risk assessment tool?

Climate change favors weather conditions conducive to wildland fires. The intensity and frequency of forest fires are increasing, and fire seasons are lengthening. Exposure of human populations to smoke emitted by these fires increases, thereby contributing to airborne pollution through the emission of gas and particulate matter (PM). The adverse health outcomes associated with wildland fire exposure represent an important burden on the economies and health systems of societies. Even though cardiovascular diseases (CVDs) are the main of cause of the global burden of diseases attributable to PM exposure, it remains difficult to show reliable associations between exposure to wildland fire smoke and cardiovascular disease risk in population-based studies. Optimal health requires a resilient and adaptable network of small blood vessels, namely, the microvasculature. Often alterations of this microvasculature precede the occurrence of adverse health outcomes, including CVD. Biomarkers of microvascular health could then represent possible markers for the early detection of poor cardiovascular outcomes. This review aims to synthesize the current literature to gauge whether assessing the microvasculature can better estimate the cardiovascular impact of wildland fires.

Targeting gut microbiota-derived kynurenine to predict and protect the remodeling of the pressure-overloaded young heart

Pressure-overloaded left ventricular remodeling in young population is progressive and readily degenerate into heart failure. The aims of this study were to identify a plasma metabolite that predicts and is mechanistically linked to the disease. Untargeted metabolomics determined elevated plasma kynurenine (Kyn) in both the patient cohorts and the mice model, which was correlated with remodeling parameters. In vitro and in vivo evidence, combined with single-nucleus RNA sequencing (snRNA-seq), demonstrated that Kyn affected both cardiomyocytes and cardiac fibroblasts by activating aryl hydrocarbon receptors (AHR) to up-regulate hypertrophy- and fibrosis-related genes. Shotgun metagenomics and fecal microbiota transplantation revealed the existence of the altered gut microbiota-Kyn relationship. Supplementation of selected microbes reconstructed the gut microbiota, reduced plasma Kyn, and alleviated ventricular remodeling. Our data collectively discovered a gut microbiota-derived metabolite to activate AHR and its gene targets in remodeling young heart, a process that could be prevented by specific gut microbiota modulation.