Reduced dynamic changes in pulmonary artery compliance during isometric handgrip exercise in patients with heart failure.

Exercise intolerance is a debilitating symptom in heart failure (HF), adversely affecting both quality of life and long-term prognosis. Emerging evidence suggests that pulmonary artery (PA) compliance may be a contributing factor. This study aims to non-invasively assess PA compliance and its dynamic properties during isometric handgrip (HG) exercise in HF patients and healthy controls, using cardiovascular magnetic resonance (CMR). We prospectively enrolled 36 subjects, comprising 17 HF patients (NYHA class II and III) and 19 healthy controls. Participants performed an HG test, and we assessed changes in PA compliance and hemodynamic flow parameters using advanced CMR techniques. We also explored the relationship between CMR-derived PA compliance metrics and established clinical indicators, ensuring the validity of our findings through intra- and interobserver agreements. HF patients had significantly lower resting PA compliance compared to controls (28.9% vs. 50.1%, p < 0.01). During HG exercise, HF patients exhibited a dampened adaptability in PA compliance. Hemodynamic responses, including heart rate and blood pressure, were not significantly different between the groups. Further analyses revealed a significant correlation between changes in PA compliance and functional capacity, and an inverse relationship with NYHA class. Our study demonstrates a marked difference in PA vascular responses during HG exercise between HF patients and healthy controls. The compromised adaptability in PA compliance in HF patients is correlated with diminished functional capacity. These findings have significant clinical implications and may guide future interventional strategies in HF management.

Impaired Cardiac Sympathetic Activity Is Associated With Myocardial Remodeling and Established Biomarkers of Heart Failure.

BACKGROUND: 123Iodine-meta-iodobenzylguanidine scintigraphy is useful for assessing cardiac autonomic dysfunction and predict outcomes in heart failure (HF). The relationship of cardiac sympathetic function with myocardial remodeling and diffuse fibrosis remains largely unknown. We aimed to evaluate the cardiac sympathetic function of patients with HF and its relation with myocardial remodeling and exercise capacity. METHODS AND RESULTS: Prospectively enrolled patients with HF (New York Heart Association class II-III) were stratified into HF with preserved left ventricular ejection fraction [LVEF] ≥45%) and reduced LVEF. Ventricular morphology/function and myocardial extracellular volume (ECV) fraction were quantified by cardiovascular magnetic resonance, global longitudinal strain by echocardiography, cardiac sympathetic function by heart-to-mediastinum ratio from 123iodine-meta-iodobenzylguanidine scintigraphy. All participants underwent cardiopulmonary exercise testing. The cohort included 33 patients with HF with preserved LVEF (LVEF, 60±10%; NT-proBNP [N-terminal pro-B-type natriuretic peptide], 248 [interquartile range, 79-574] pg/dL), 28 with HF with reduced LVEF (LVEF, 30±9%; NT-proBNP, 743 [interquartile range, 250-2054] pg/dL) and 20 controls (LVEF, 65±5%; NT-proBNP, 40 [interquartile range, 19-50] pg/dL). Delayed (4 hours) 123iodine-meta-iodobenzylguanidine heart-to-mediastinum ratio was lower in HF with preserved LVEF (1.59±0.25) and HF with reduced LVEF (1.45±0.16) versus controls (1.92±0.24; P<0.001), and correlated negatively with diffuse fibrosis assessed by ECV (R=-0.34, P<0.01). ECV in segments without LGE was increased in HF with preserved ejection fraction (0.32±0.05%) and HF with reduced left ventricular ejection fraction (0.31±0.04%) versus controls (0.28±0.04, P<0.05) and was associated with the age- and sex-adjusted maximum oxygen consumption (peak oxygen consumption); (R=-0.41, P<0.01). Preliminary analysis indicates that cardiac sympathetic function might potentially act as a mediator in the association between ECV and NT-proBNP levels. CONCLUSIONS: Abnormally low cardiac sympathetic function in patients with HF with reduced and preserved LVEF is associated with extracellular volume expansion and decreased cardiopulmonary functional capacity.

The relationship between aerobic capacity and left atrial size in healthy young males: An observational study.

Aerobic capacity, defined as peak oxygen uptake (peakVO2), is a marker for aerobic fitness and is associated with left ventricular (LV) systolic and diastolic function. The aim of the study was to explore the relation between left atrial (LA) volume index (LAVI) and aerobic capacity in healthy young male adults. One hundred three healthy young male subjects (mean age: 34.2 ±â€…5.5years) were consecutively included in the study. All subjects underwent echocardiography to assess LAVI, LV systolic and diastolic functions. Aerobic capacity was assessed by cardiopulmonary exercise testing. All patients had normal left ventricular ejection fraction (LVEF). One hundred one subjects had normal LAVI (≤34 mL/m2) while 2 subjects had mildly increased LAVI (35-41 mL/m2). Mean peakVO2 predicted was 82.2 ±â€…14.4%. 64subjects (62.1%) had a peakVO2 < 85% of age-predicted and sex-predicted values and they had higher LAVI compared to those who had a peakVO2 higher than 85% of age-predicted and sex-predicted values (22.0 ±â€…4.8 mL/m2 vs 20.3 ±â€…4.1 mL/m2, P = .055). Notably, only LAVI showed a significant correlation with peakVO2 and predicted breathing reserve (BR), while anaerobic threshold correlated with both LAVI and LVEF. Age was also a significant factor, negatively impacting peakVO2 (r = -0.265, P = .007) and predicted BR (r = -0.282, P = .004). Multivariate analysis revealed that both LAVI and age were independent predictors of peakVO2 and predicted BR. This study suggests that LAVI can be a valuable indicator of aerobic capacity in apparently healthy young males.

Relevance of multidimensional dyspnea assessment in the context of pulmonary rehabilitation.

Objectives: While dyspnea is the main symptom in chronic obstructive pulmonary disease (COPD), it is often inadequately evaluated in pulmonary rehabilitation (PR), as it is typically measured using only the impact dimension (ID). However, dyspnea is a multidimensional construct including perception (PD) and emotional (ED) domains. Our work aimed to study the complementarity of dyspnea dimensions and their respective ability to identify different evolutions during PR. Methods: 145 people with COPD attending PR were included in this retrospective study. Dyspnea scores from the modified Medical Research Council scale (ID) and the Multidimensional Dyspnea Profile questionnaire (PD/ED), exercise capacity, quality of life at the start (T1) and the end of PR (T2) were collected from existing databases/medical files. The evolution of each dyspnea dimension was evaluated using the delta score between T2-T1. PR response was defined using the minimal clinically important difference. Results: Our results show that each dyspnea dimension was associated with different health-outcomes. Positive correlations were found between PD-ED at baseline and between their T2-T1 delta score (ρ = 0.51; ρ = 0.41 respectively, p < .01), but there was no significant correlation between ID-PD or -ED (p > .05). 51% of the patients did not respond on ID, but 85% of them nonetheless responded on either PD or ED. Finally, 92% of patients responded on at least one dimension after PR. Discussion: Our study emphasizes the significance of assessing each dimension of dyspnea independently and complementary, as dimensions are associated with different elements and evolve differently under PR effects. This approach is crucial to identifying weak points and allows professionals to focus on program elements that most effectively address the specific dimension causing problems.

Racial Differences in Diabetic Cardiomyopathy: The ARISE-HF Trial.

BACKGROUND: Diabetic cardiomyopathy (DbCM) increases risk of overt heart failure in individuals with diabetes mellitus. Racial and ethnic differences in DbCM remain unexplored. OBJECTIVES: The authors sought to identify racial and ethnic differences among individuals with type 2 diabetes mellitus, structural heart disease, and impaired exercise capacity. METHODS: The ARISE-HF (Aldolase Reductase Inhibitor for Stabilization of Exercise Capacity in Heart Failure) trial is assessing the efficacy of an aldose reductase inhibitor for exercise capacity preservation in 691 persons with DbCM. Baseline characteristics, echocardiographic parameters, and functional capacity were analyzed and stratified by race and ethnicity. RESULTS: The mean age of the study participants was 67.4 years; 50% were women. Black and Hispanic patients had lower use of diabetes mellitus treatments. Black patients had poorer baseline ventricular function and more impaired global longitudinal strain. Overall, health status was preserved, based on Kansas City Cardiomyopathy Questionnaire scores, but reduced exercise capacity was present as evidenced by reduced Physical Activity Scale for the Elderly (PASE) scores. When stratified by race and ethnicity and compared with the entire cohort, Black patients had poorer health status, more reduced physical activity, and a greater impairment in exercise capacity during cardiopulmonary exercise testing, whereas Hispanic patients also displayed compromised cardiopulmonary exercise testing functional capacity. White patients demonstrated higher physical activity and functional capacity. CONCLUSIONS: Racial and ethnic differences exist in baseline characteristics of persons affected by DbCM, with Black and Hispanic study participants demonstrating higher risk features. These insights inform the need to address differences in the population with DbCM. (Safety and Efficacy of AT-001 in Patients With Diabetic Cardiomyopathy [ARISE-HF]; NCT04083339).

The relationship between lung function, exercise capacity, oxidant and antioxidant response in primary ciliary dyskinesia and cystic fibrosis.

BACKGROUND: There is a need to identify the complex interplay between various physiological mechanisms in primary ciliary dyskinesia (PCD) and cystic fibrosis (CF). The study investigated the interaction between respiratory function, exercise capacity, muscle strength, and inflammatory and oxidant/antioxidant responses in patients with PCD and CF. METHODS: The study included 30 PCD patients, 30 CF patients, and 29 age and sex-matched healthy subjects. Exercise capacity was assessed using the modified shuttle walk test (MSWT). Handgrip strength (HGS) was used to evaluate general muscle strength. Oxidative stress-inflammatory parameters were also assessed. Pulmonary function test was performed by spirometry. Regarding the forced expiratory volume in 1 second (FEV1) z-score, patients with PCD and CF were subdivided into normal, mild, and severe/moderate groups. RESULTS: Forced vital capacity (FVC) z-scores were lower in PCD and CF patients than controls. FEV1, FEV1/FVC, peak expiratory flow (PEF), and forced mid expiratory flow (FEF25-75%) z-scores were lower in PCD than in the other groups. HGS was lower in both mild PCD and normal CF patients relative to the controls. MSWT distance was lower in severe/moderate PCD patients than controls. Catalase (CAT), glutathione S-transferase (GST), glutathione peroxidase (GPx), and malondialdehyde (MDA) levels did not differ significantly among the study groups, but superoxide dismutase (SOD) level in severe/moderate PCD, and glutathione (GSH) level in normal CF were higher than in controls. Interleukin-6 (IL-6) level was higher in patients with normal PCD and CF compared to the controls. IL-1ß level was higher in PCD compared to controls. Additionally, correlations among these parameters were also determined in some patient groups. CONCLUSION: Homeostasis related to respiratory function, aerobic performance, muscle strength, inflammatory response, and oxidant/antioxidant balance were affected in PCD and CF. Evaluating these mechanisms together may contribute to elucidating the pathophysiology of these rare diseases.

The Long-Term Benefit of Exercise With and Without Manual Therapy for Mild Chronic Obstructive Pulmonary Disease: A Randomized Controlled Trial.

PURPOSE: Chronic obstructive pulmonary disease (COPD) is characterized by decreasing exercise capacity and deteriorating quality of life (QoL). Recent evidence indicates that combining exercise with manual therapy (MT) delivers greater improvements in exercise capacity than exercise alone in moderate COPD. The aim of this study was to investigate whether this combination delivers similar results in mild COPD. METHODS: A total of 71 participants aged 50-65 yr with mild COPD were randomly allocated to two groups: exercise only (Ex) or MT plus exercise (MT + Ex). Both groups received 16 wk of exercise with the MT + Ex group also receiving 8 MT sessions. Lung function (forced vital capacity [FVC] and forced expiratory volume in the 1 st sec [FEV 1 ]), exercise capacity (6-min walk test [6MWT]), and QoL (St George's Respiratory Questionnaire [SGRQ] and Hospital Anxiety and Depression Scale [HADS]) were measured at baseline, 4, 8, 16, 24, 32, and 48 wk. RESULTS: Although there was no difference in the mean effect over time between groups for lung function (FEV 1 , P = .97; FVC, P = .98), exercise capacity (6MWT, P = .98), and QoL (SGRQ, P = .41; HADS anxiety, P = .52; and HADS depression, P = .06), there were clinically meaningful improvements at 48 wk for 6MWT (30 m; 95% CI, 10-51 m; P < .001), SGRQ (6.3 units; 95% CI, 2.5-10.0; P < .001), and HADS anxiety (1.5 units; 95% CI, 0.3-2.8 units; P = .006) across the entire cohort. CONCLUSIONS: While adding MT to Ex did not produce any additional benefits, exercise alone did deliver sustained modest improvements in exercise capacity and QoL in mild COPD.

Association of Sarcopenia and Oxygen Uptake Efficiency Slope in Male Patients With Heart Failure.

PURPOSE: Sarcopenia, the loss of muscle mass and function, is a common comorbidity in patients with heart failure (HF). The skeletal muscle modulates the respiratory response during exercise. However, whether ventilatory behavior is affected by sarcopenia is still unknown. METHODS: We enrolled 169 male patients with HF. Muscle strength was measured by a handgrip dynamometer. Body composition was measured with dual-energy X-ray absorptiometry. Sarcopenia was defined by handgrip strength <27 kg and appendicular lean mass divided by height squared (ALM/height 2 ) <7.0 kg/m 2 . Oxygen uptake efficiency slope (OUES), ventilation (VE), oxygen uptake (VO 2 ), and carbon dioxide output (VCO 2 ) were measured by a cardiopulmonary exercise test. RESULTS: Sarcopenia was identified in 29 patients (17%). At the first ventilatory threshold, VE/VO 2 (36.9 ± 5.9 vs 32.7 ± 6.5; P = .003) and VE/VCO 2 (39.8 ± 7.2 vs 35.3 ± 6.9; P = .004) were higher in patients with sarcopenia compared to those without sarcopenia. At the exercise peak, compared to patients without sarcopenia, patients with sarcopenia had lower OUES (1186 ± 295 vs 1634 ± 564; P < .001), relative VO 2 (16.2 ± 5.0 vs 19.5 ± 6.5 mL/kg/min; P = .01), and VE (47.3 ± 10.1 vs 63.0 ± 18.2 L/min; P < .0001), while VE/VCO 2 (42.9 ± 8.9 vs 38.7 ± 8.4; P = .025) was increased. OUES was positively correlated with ALM/height 2 ( r = 0.36; P < .0001) and handgrip strength ( r = 0.31; P < .001). Hemoglobin (OR = 1.149; 95% CI, 0.842-1.570; P = .038), ALM/height 2 (OR = 2.166; 95% CI, 1.338-3.504; P = .002), and VO 2peak (OR = 1.377; 95% CI, 1.218-1.557; P < .001) were independently associated with OUES adjusted by cofounders. CONCLUSIONS: Our results suggest that sarcopenia is related to impaired ventilatory response during exercise in patients with HF.

Impaired longitudinal systolic-diastolic coupling and cardiac response to exercise in patients with hypertrophic cardiomyopathy.

BACKGROUND: In patients with hypertrophic cardiomyopathy (HCM), impaired augmentation of stroke volume and diastolic dysfunction contribute to exercise intolerance. Systolic-diastolic (S-D) coupling characterizes how systolic contraction of the left ventricle (LV) primes efficient elastic recoil during early diastole. Impaired S-D coupling may contribute to the impaired cardiac response to exercise in patients with HCM. METHODS: Patients with HCM (n = 25, age = 47 ± 9 years) and healthy adults (n = 115, age = 49 ± 10 years) underwent a cardiopulmonary exercise testing (CPET) and echocardiogram. S-D coupling was defined as the ratio of LV longitudinal excursion of the mitral annulus during early diastole (EDexc) and systole (Sexc) and compared between groups. Peak oxygen uptake (peak V̇O2) (Douglas bags), cardiac index (C2H2 rebreathe), and stroke volume index (SVi) were assessed during CPET. Linear regression was performed between S-D coupling and peak V̇O2, peak cardiac index, and peak SVi. RESULTS: S-D coupling was lower in HCM (Controls: 0.63 ± 0.08, HCM: 0.56 ± 0.10, p < 0.001). Peak V̇O2 and stroke volume reserve were lower in patients with HCM (Peak VO2 Controls: 28.5 ± 5.5, HCM: 23.7 ± 7.2 mL/kg/min, p < 0.001, SV reserve: Controls 39 ± 16, HCM 30 ± 18 mL, p = 0.008). In patients with HCM, S-D coupling was associated with peak V̇O2 (r = 0.47, p = 0.018), peak cardiac index (r = 0.60, p = 0.002), and peak SVi (r = 0.63, p < 0.001). CONCLUSION: Systolic-diastolic coupling was impaired in patients with HCM and was associated with fitness and the cardiac response to exercise. Inefficient S-D coupling may link insufficient stroke volume generation, diastolic dysfunction, and exercise intolerance in HCM.

Exercise response in post-acute coronary syndrome patients survived to COVID-19 infection.

AIMS: Many studies evaluated the functional response in post-Covid-19 patients; however, they systematically excluded patients with concomitant acute coronary syndrome (ACS). We evaluated the long-term functional capacity assessed by cardiopulmonary exercise test (CPET) in patients hospitalized for ACS and concomitant SARS-CoV2 infection. The secondary aim was to investigate the functional response in patients with symptoms related to "long COVID-19 syndrome" (LCS). METHODS: This cross-sectional case-control study compared 20 patients with ACS and concomitant SARS-COV2 infection with 20 patients without COVID-19. At the follow-up visit (between 6 and 12 months after revascularization procedure) all patients underwent a CPET. RESULTS: Patients with previous ACS and concomitant COVID-19 showed a reduced O2 consumption than controls (predicted peak V̇O2 74.00% vs 86.70%; p = 0.01) with a high degree of ventilatory inefficiency (VE/ V̇CO2 slope 38.04 vs 30.31; p = 0.002). 50% of subjects with previous COVID-19 disease showed symptoms related to "LCS"; this subgroup demarcates the characteristic reduced exercise capacity found in the entire COVID + group. CONCLUSIONS: This study is the first in literature having analyzed the long-term functional capacity phenotype in a population of ACS patients and concomitant SARS-CoV2 infection. Severe ventilatory inefficiency emerged as the functional signature of these patients. Moreover, the subset of patients with symptoms related to LCS has the most compromised long term reduced exercise capacity and an altered ventilation control.

Echocardiographic assessment for cardiopulmonary function in patients with congenital heart disease-related pulmonary arterial hypertension.

BACKGROUND: For patients with congenital heart disease-related pulmonary arterial hypertension (CHD-PAH), cardiopulmonary exercise testing (CPET) can reflect cardiopulmonary reserve function. However, CPET may not be readily accessible for patients with high-risk conditions or limited mobility due to disability. Echocardiography, on the other hand, serves as a widely available diagnostic tool for all CHD-PAH patients. This study was aimed to identify the parameters of echocardiography that could serve as indicators of cardiopulmonary function and exercise capacity. METHODS: A cohort of 70 patients contributed a total of 110 paired echocardiogram and CPET results to this study, with 1 year interval for repeated examinations. Echocardiography and exercise testing were conducted following standardized procedures, and the data were collected together with clinically relevant indicators for subsequent statistical analysis. Demographic comparisons were performed using t-tests and chi-square tests. Univariate and multivariate analyses were conducted to identify potential predictors of peak oxygen uptake (peak VO2) and the carbon dioxide ventilation equivalent slope (VE/VCO2 slope). Receiver operating characteristic (ROC) analysis was used to assess the performance of the parameters. RESULTS: The ratio of tricuspid annular plane systolic excursion to pulmonary artery systolic pressure (TAPSE/PASP) was found to be the only independent indicator significantly associated with both peak VO2 and VE/VCO2 slope (both p < 0.05). Additionally, left ventricular ejection fraction (LVEF) and right ventricular fractional area change (FAC) were independently correlated with the VE/VCO2 slope (both p < 0.05). TAPSE/PASP showed the highest area under the ROC curve (AUC) for predicting both a peak VO2 ≤ 15 mL/kg/min and a VE/VCO2 slope ≥ 36 (AUC = 0.91, AUC = 0.90, respectively). The sensitivity and specificity of TAPSE/PASP at the optimal threshold exceeded 0.85 for both parameters. CONCLUSIONS: TAPSE/PASP may be a feasible echocardiographic indicator for evaluating exercise tolerance.

Longitudinal strain correlates with 6-minute walk distance whereas ejection fraction and diastolic parameters do not.

BACKGROUND: Impaired functional capacity is a common symptom in patients with heart failure. Standard measures of left ventricular (LV) function, such as ejection fraction (EF) and LV diastolic parameters, do not correlate with measures of functional capacity. The aim of this study is to determine if measures of global and regional LV strain better correlate with 6-minute walk distance than does EF or measures of LV diastolic function. METHODS: 120 patients referred to a cardiology clinic for evaluation of known or suspected heart failure were approached for enrollment. Of those 120 patients, 58 had an echocardiogram within 3 months of enrollment with images adequate for regional and global strain assessment, had no contra-indication to exercise testing, and had no previously documented non-cardiac explanation for dyspnea on exertion. In those 58 patients, 6-minute walk distance was measured, LV EF was determined with Simpson's biplane method, and global and regional longitudinal strain were measured with TomTec Image Arena 4.5.1 software. RESULTS: LV EF had no correlation with 6-minute walk distance (r = 0.22, p = 0.09) even when controlling for age, gender, and BMI (p = 0.07). No measures of LV diastolic function (including E velocity, Deceleration Time, e' annular velocities, or E/e') had a correlation with 6-minute walk distance. Multiple measures of global and regional LV longitudinal systolic function had a correlation with 6-minute walk distance. Longitudinal strain of the basal LV segments had the strongest correlation with 6-minute walk distance (r= -0.36, p = 0.005), and correlation persisted after controlling for age, gender, BMI, and systolic blood pressure (p = 0.004). CONCLUSIONS: Longitudinal strain correlates with a measure of functional capacity, but LVEF and traditional measures of LV diastolic dysfunction do not. Measures of longitudinal strain, especially in basal LV segments, will likely be an important marker of clinically relevant LV function.

Interventions with a clear focus on achieving behaviour change are important for maintaining training-related gains in people with chronic obstructive pulmonary disease: a systematic review.

QUESTIONS: In people with chronic obstructive pulmonary disease (COPD) who complete an exercise training program (ETP) offered at a sufficient dose to result in training-related gains, to what extent are these gains maintained 12 months after program completion? Do variables such as the application of behaviour change techniques moderate the maintenance of these training-related gains? DESIGN: Systematic review, meta-analysis and meta-regression of randomised controlled trials. PARTICIPANTS: People with stable COPD. INTERVENTION: Trials were included if they applied ≥ 4 weeks of a whole-body ETP and reported outcome data immediately following program completion and 12 months after initial program completion. The control group received usual care that did not include a formal exercise training component. OUTCOME MEASURES: Exercise tolerance, health-related quality of life and dyspnoea during activities of daily living. DATA SOURCES: EMBASE, PEDro, PubMed and the Cochrane Library. RESULTS: Nineteen randomised trials with 2,103 participants were found, of which 12 had a sufficiently similar design to be meta-analysed. At 12 months after ETP completion, compared with the control group, the experimental group demonstrated better exercise tolerance (SMD 0.48, 95% CI 0.19 to 0.77) and quality of life (SMD 0.22, 95% CI 0.03 to 0.41) with no clear effect on dyspnoea. Meta-regression using data from all 19 trials demonstrated that the magnitude of between-group differences at the 12-month follow-up was moderated by: behaviour change being a core aim of the strategies implemented following completion of the ETP; the experimental group receiving more behaviour change techniques during the program; and the magnitude of between-group change achieved from the program. CONCLUSION: At 12 months after completion of an ETP of ≥ 4 weeks, small gains were maintained in exercise tolerance and health-related quality of life. Applying behaviour change techniques with a clear focus on participants integrating exercise into daily life beyond initial program completion is important to maintain training-related gains. REGISTRATION: CRD42020193833.

Strength training improves functional capacity of individuals with chronic heart failure: Randomized clinical trial.

INTRODUCTION: Chronic heart failure (CHF) is characterized by dyspnea, exercise intolerance and impaired quality of life. Physical exercise is a key point in the treatment of these outcomes. OBJECTIVE: To evaluate the effect of 24 weeks of two different training strategies on functional capacity, muscle strength and quality of life in individuals with CHF. METHODS: The following tests and evaluations were performed before and after 24 weeks of training: exercise test, one-repetition maximum test (1- RM) and Minnesota Living with Heart Failure Questionnaire (MLHFQ). Subjects were randomized according to the modality they would perform first: aerobic training group (ATG - n=6) or strength training group (STG - n=7). RESULTS: The sample consisted of 13 individuals (10 men), aged 55 ± 12 years and a left ventricular ejection fraction (LVEF) of 38.8 ± 5.3%. There was a significant increase in V'O 2peak only in STG (STG: 26.92 ± 9.81 vs 30.52 ± 8.39 mL.kg -1 .min -1 - p=0.025; ATG: 19.60 ± 7,00 vs 22.42 ± 8.54 mL.kg -1 .min -1 - p=0.119). Both groups showed significant improvements in muscle strength (STG: 45 ± 17 vs 51 ± 20 kg - p=0.001; ATG: 38 ± 19 vs 42 ± 20 kg - p=0.012). There was no significant difference in quality of life (STG: 30 ± 18 vs 24 ± 20 - p=0.109; ATG: 36 ± 16 vs 26 ± 15 - p=0.143). CONCLUSION: The early implementation of strength training improves functional capacity and muscle strength of individuals with CHF.

Mitochondria Transplantation: Rescuing Innate Muscle Bioenergetic Impairment in a Model of Aging and Exercise Intolerance.

ABSTRACT: Arroum, T, Hish, GA, Burghardt, KJ, Ghamloush, M, Bazzi, B, Mrech, A, Morse, PT, Britton, SL, Koch, LG, McCully, JD, Hüttemann, M, and Malek, MH. Mitochondria transplantation: Rescuing innate muscle bioenergetic impairment in a model of aging and exercise intolerance. J Strength Cond Res 38(7): 1189-1199, 2024-Mitochondria, through oxidative phosphorylation, are crucial for energy production. Disease, genetic impairment, or deconditioning can harm muscle mitochondria, affecting energy production. Endurance training enhances mitochondrial function but assumes mobility. Individuals with limited mobility lack effective treatments for mitochondrial dysfunction because of disease or aging. Mitochondrial transplantation replaces native mitochondria that have been damaged with viable, respiration-competent mitochondria. Here, we used a rodent model selectively bred for low-capacity running (LCR), which exhibits innate mitochondrial dysfunction in the hind limb muscles. Hence, the purpose of this study was to use a distinct breed of rats (i.e., LCR) that display hereditary skeletal muscle mitochondrial dysfunction to evaluate the consequences of mitochondrial transplantation. We hypothesized that the transplantation of mitochondria would effectively alleviate mitochondrial dysfunction in the hind limb muscles of rats when compared with placebo injections. In addition, we hypothesized that rats receiving the mitochondrial transplantation would experience an improvement in their functional capacity, as evaluated through incremental treadmill testing. Twelve aged LCR male rats (18 months old) were randomized into 2 groups (placebo or mitochondrial transplantation). One LCR rat of the same age and sex was used as the donor to isolate mitochondria from the hindlimb muscles. Isolated mitochondria were injected into both hindlimb muscles (quadriceps femoris, tibialis anterior (TA), and gastrocnemius complex) of a subset LCR (n = 6; LCR-M) rats. The remaining LCR (n = 5; LCR-P) subset received a placebo injection containing only the vehicle without the isolated mitochondria. Four weeks after mitochondrial transplantation, rodents were euthanized and hindlimb muscles harvested. The results indicated a significant (p < 0.05) increase in mitochondrial markers for glycolytic (plantaris and TA) and mixed (quadricep femoris) muscles, but not oxidative muscle (soleus). Moreover, we found significant (p < 0.05) epigenetic changes (i.e., hypomethylation) at the global and site-specific levels for a key mitochondrial regulator (transcription factor A mitochondrial) between the placebo and mitochondrial transplantation groups. To our knowledge, this is the first study to examine the efficacy of mitochondrial transplantation in a rodent model of aging with congenital skeletal muscle dysfunction.

Effectiveness of pulmonary rehabilitation programmes and/or respiratory muscle training in patients with post-COVID conditions: a systematic review.

BACKGROUND: The term "post-COVID-19 condition" refers to the symptomatology that appears between four to twelve weeks after Covid-19 infection. These symptoms can persist for weeks or even months, significantly diminishing the quality of life for affected individuals. The primary objective of this study was to assess the effectiveness of pulmonary rehabilitation programs and/or respiratory muscle training on respiratory sequelae in patients with post-COVID condition. METHODS: The literature search was conducted in the following databases: PubMed, PEDro, Embase, Cochrane, Scopus, and Web of Science. Randomized clinical trials were included in which participants were aged 18 years or older. Articles were excluded if at least one of the therapies did not involve pulmonary rehabilitation or respiratory muscle training, if the participants were COVID positive, if studies lacked results, and finally, if interventions were conducted without supervision or at home. This review only encompasses supervised non-virtual interventions. This study adheres to the PRISMA statement and has been registered in the PROSPERO database (CRD42023433843). RESULTS: The outcomes obtained in the included studies are assessed across the following variables: Exercise capacity using the 6-minute walk test, Dyspnea, fatigue, Pulmonary function, Maximum inspiratory pressure, and Quality of life. CONCLUSION: Despite the absence of a specific treatment at present, it was evident from this review that a well-structured pulmonary rehabilitation program that incorporates both aerobic and muscular strength exercises along with techniques and inspiratory muscle exercises was the most effective form of treatment.

Iron deficiency in patients with a Fontan circulation and its impact on exercise capacity.

BACKGROUND: Iron deficiency (ID) has been reported in patients with congenital heart disease. There is, however, a scarcity of data on its prevalence in patients with a Fontan circulation. The aim of this study is to investigate the prevalence of ID in Fontan patients and to investigate the association between ID and exercise capacity in this population. METHODS AND RESULTS: Blood count and haematological parameters were determined in plasma of 61 Fontan patients (51% female, mean age 29±9 years). ID was defined as transferrin saturation (TSAT) ≤19.8%. The prevalence of ID was 36% (22/61 patients). Especially among women, the diagnosis of ID was highly prevalent (52%) despite normal haemoglobin levels (153.7±18.4 g/L). Mean ferritin levels were 98±80 µg/L and mean TSAT levels were 22%±12%. Cardiopulmonary exercise testing was performed in 46 patients (75%). Patients with ID had a lower peak oxygen uptake (V̇O2peak) (1397±477 vs 1692±530 mL/min; p=0.039), although this relationship was confounded by sex. The presence of ID increased the likelihood of not achieving a respiratory exchange ratio (RER) ≥1.1 by 5-fold (p=0.035). CONCLUSION: ID is highly prevalent among patients with a Fontan circulation. V̇O2peak is lower in patients with ID. Fontan patients with ID are less likely to achieve an RER≥1.1 during cardiopulmonary exercise testing.

Effects of exercise training on cardiac output in subjects with heart failure with preserved ejection fraction (HFpEF) - a protocol for a systematic review and meta-analysis.

BACKGROUND: Patients with heart failure with preserved ejection fraction (HFpEF) commonly experience exercise intolerance, resulting in reduced cardiorespiratory fitness. This is characterised by a decreased maximal oxygen uptake (V̇O2peak), which is determined by the product of cardiac output (CO) and arteriovenous oxygen difference (a-vDO2). While exercise training has been shown to improve V̇O2peak in HFpEF patients, the effects on CO remain unclear. The aim of this study is to systematically review and analyse the current evidence on the effects of supervised exercise training on CO in patients with HFpEF. METHODS: We will systematically search for literature describing the effects of supervised exercise training on CO in patients with HFpEF. All eligible studies published before 30 June 2023 in the following electronic databases will be included: MEDLINE (Ovid), Embase (Ovid), SPORTDiscus (EBSCOhost), and CENTRAL (Cochrane Library). Effect sizes will be extracted for CO before and after a supervised exercise training intervention at rest and maximal exercise. Mass of heterogeneity (I2) will be calculated, and either fixed-effect models or random-effect models will be used for meta-analysis. To detect a potential publication bias, funnel plot analyses will be performed. DISCUSSION: While several studies have reported a positive effect of supervised exercise training on cardiorespiratory fitness, attempts to assess the underlying determinants of V̇O2peak, CO, and a-vDO2 are much scarcer, especially in patients with HFpEF. From a physiological perspective, measuring CO before and after supervised exercise training seems to be a reasonable way to accurately operationalise a potential improvement in cardiac function. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42022361485.