Aerobic exercise and inspiratory muscle training increase functional capacity in patients with univentricular physiology after Fontan operation: A randomized controlled trial

The impact of exercise training on muscle sympathetic nerve activity: a systematic review and meta-analysis

The purpose of this systematic review and meta-analysis was to examine the effects of exercise training on muscle sympathetic nerve activity (MSNA) in humans. Studies included exercise interventions [randomized controlled trials (RCTs), nonrandomized controlled trials (non-RCTs), or pre-to-post intervention] that reported on adults (≥18 yr) where MSNA was directly assessed using microneurography, and relevant outcomes were assessed [MSNA (total activity, burst frequency, burst incidence, amplitude), heart rate, blood pressure (systolic blood pressure, diastolic blood pressure, or mean blood pressure), and aerobic capacity (maximal or peak oxygen consumption)]. Forty intervention studies (n = 1,253 individuals) were included. RCTs of exercise compared with no exercise illustrated that those randomized to the exercise intervention had a significant reduction in MSNA burst frequency and incidence compared with controls. This reduction in burst frequency was not different between individuals with cardiovascular disease compared with those without. However, the reduction in burst incidence was greater in those with cardiovascular disease [9 RCTs studies, n = 234, mean difference (MD) -21.08 bursts/100 hbs; 95% confidence interval (CI) -16.51, -25.66; I2 = 63%] compared with those without (6 RCTs, n = 192, MD -10.92 bursts/100 hbs; 95% CI -4.12, -17.73; I2 = 76%). Meta-regression analyses demonstrated a dose-response relationship where individuals with higher burst frequency and incidence preintervention had a greater reduction in values post-intervention. These findings suggest that exercise training reduces muscle sympathetic nerve activity, which may be valuable for improving cardiovascular health.NEW & NOTEWORTHY This systematic review and meta-analysis suggests exercise training reduces muscle sympathetic nerve activity (MSNA), which may be valuable for improving cardiovascular health. The reduction in burst incidence was greater among individuals with cardiovascular disease when compared with those without; exercise training may be particularly beneficial for individuals with cardiovascular disease. Meta-regression analyses demonstrated a dose-response relationship, where individuals with higher sympathetic activity preintervention had greater reductions in sympathetic activity post-intervention.

Flexibility: A Hidden But Trainable Morbidity in Pediatric Patients with Congenital Heart Disease

Flexibility is important for range of motion, muscular performance, and injury prevention with exercise. Promoting exercise is important for patients with congenital and pediatric acquired heart disease (CHD), yet there are a paucity of data addressing flexibility in this population. We hypothesized that flexibility was worse in pediatric patients with CHD than the general population but could be improved with directed training. Patients at Boston Children's Hospital who participated in the pediatric Cardiac Fitness Program between 09/2016 and 11/2022 were retrospectively analyzed. Flexibility was assessed via sit-and-reach (SaR) box. Data from baseline and 60 days into the fitness program intervention were compared to age-matched population norms, and changes over time were assessed. Analyses were also stratified by sex and history of sternotomy. Patients with paired baseline and 60-day data were analyzed (n = 46, age 8-23 years old, 52% male). The mean SaR at baseline for CHD patients was 24.3 cm, significantly lower than the population norm (p = 0.002). The mean for male (n = 24, 21.2 cm) and female (n = 22, 27.2 cm) CHD patients was significantly lower than their respective population norms (p = 0.017 and p = 0.026, respectively). After the fitness intervention, flexibility in CHD patients significantly improved to normal, including patients with a history of sternotomy. Flexibility was significantly lower in CHD patients than the general population, but normalized with training. Further research is warranted to investigate associations of flexibility with other measures of fitness, cardiovascular status, and quality of life, as well as benefits gained with training.

Respiratory Muscle Function and Exercise Performance in Adult Patients with Fontan Circulation

At rest, a good Fontan circulation can provide a normal cardiac output (CO). However, as a consequence of its unique hemodynamic nature, the limitations of the Fontan circuit are exposed during exercise. We aimed to provide a comprehensive assessment of the pathophysiology of exercise in adult Fontan patients (FPs) and identify factors limiting their functional capacity (FC). In a single-center study conducted in 37 FPs aged ≥16 years and 19 healthy-controls (HCs) who underwent CPET on a cycle ergometer in February and March 2022, the mean peakVO₂ was 21 ± 5.4 mL/kg/min, which was 55% of the predicted value. Morphologically, the left single ventricle showed a higher peakVO₂% predicted value (57.4 ± 14.4% vs. 43.4 ± 8.1%, p = 0.045). The factors associated with low peakVO₂ values were an early flattened or descending O₂ pulse at maximal exertion (52 ± 14% vs. 62 ± 12.5, p = 0.04 and 47.6 ± 9% vs. 60 ± 14, p = 0.018, respectively) and chronotropic insufficiency (53 ± 12% vs. 69.8 ± 20%, p = 0.008). The OUES was found to be a useful parameter to assess the FC in FPs in maximal and submaximal exercise testing. A strong positive correlation was observed between the %OUES and peakVO₂%predicted (r = 0.726, p > 0.001). The lung function was impaired in the FPs, mostly with a mild restrictive pattern (56.8%). The FPs showed lower inspiratory muscle strength compared to the HCs but it was not statistically associated with either the peakVO₂ or VE/VCO₂ slope. Regular intense physical activity improves one's FC. Although FPs have inspiratory muscle weakness, its impact on their FC is unclear. The peakVO₂% predicted grew progressively higher as the level of physical activity increased (low level 49.5 ± 14%, moderate level 55 ± 12%, intense level 69 ± 20%).

Pulmonary Complications in Patients With Fontan Circulation: JACC Review Topic of the Week

The Fontan operation has resulted in significant improvement in survival of patients with single ventricle physiology. As a result, there is a growing population of individuals with Fontan physiology reaching adolescence and adulthood. Despite the improved survival, there are long-term morbidities associated with the Fontan operation. Pulmonary complications are common and may contribute to both circulatory and pulmonary insufficiency, leading ultimately to Fontan failure. These complications include restrictive lung disease, sleep abnormalities, plastic bronchitis, and cyanosis. Cyanosis post-Fontan procedure can be attributed to multiple causes including systemic to pulmonary venous collateral channels and pulmonary arteriovenous malformations. This review presents the unique cardiopulmonary interactions in the Fontan circulation. Understanding the cardiopulmonary interactions along with improved recognition and treatment of pulmonary abnormalities may improve the long-term outcomes in this growing patient population. Interventions focused on improving pulmonary function including inspiratory muscle training and endurance training have shown a promising effect post-Fontan procedure.

Sarcopenia and cardiovascular diseases: A systematic review and meta-analysis

Sarcopenia is an age-related disease and is often accompanied by other diseases. Now, many studies have shown that cardiovascular diseases (CVDs) may raise the incidence rate of sarcopenia. Therefore, the purpose of this study was to conduct a systematic review and meta-analysis to investigate the prevalence of sarcopenia in patients with CVDs compared with the general population, defined as relatively healthy non-hospitalized subjects. The databases of PubMed, Embase, Medline and Web of Science were searched for eligible studies published up to 12 November 2022. Two assessment tools were used to evaluate study quality and the risk of bias. Statistical analysis was conducted using STATA 14.0 and R Version 4.1.2. Thirty-eight out of the 89 629 articles retrieved were included in our review. The prevalence of sarcopenia ranged from 10.1% to 68.9% in patients with CVDs, and the pooled prevalence was 35% (95% confidence interval [95% CI]: 28-42%). The pooled prevalence of sarcopenia was 32% (95% CI: 23-41%) in patients with chronic heart failure (CHF), 61% (95% CI: 49-72%) in patients with acute decompensated heart failure (ADHF), 43% (95% CI: 2-85%) in patients with coronary artery disease, 30% (95% CI: 25-35%) in patients with cardiac arrhythmia (CA), 35% (95% CI: 10-59%) in patients with congenital heart disease and 12% (95% CI: 7-17%) in patients with unclassed CVDs. However, in the general population, the prevalence of sarcopenia varied from 2.9% to 28.6% and the pooled prevalence was 13% (95% CI: 9-17%), suggesting that the prevalence of sarcopenia in patients with CVDs was about twice compared with the general population. The prevalence of sarcopenia was significantly higher only in patients with ADHF, CHF and CA compared with the general population. There is a positive correlation between CVDs and sarcopenia. The prevalence of sarcopenia is higher in patients with CVDs than that in the general population. With global aging, sarcopenia has brought a heavy burden to individuals and society. Therefore, it is important to identify the populations with high-risk or probable sarcopenia in order to do an early intervention, such as exercise, to counteract or slow down the progress of sarcopenia.

Comparison of Effects of Liuzijue Exercise and Conventional Respiratory Training on Patients after Cardiac Surgery: A Randomized Controlled Trial

OBJECTIVE

To evaluate the feasibility and safety of Liuzijue exercise (LE) for the clinical effect in patients after cardiac surgery.

METHODS

Totally 120 patients who underwent cardiac surgery and were admitted to the Cardiothoracic Intensive Care Unit of Nanjing Drum Tower Hospital between July and Oclober, 2022 were allocated to the LE group, the conventional respiratory training (CRT) group, and the control group by a random number table at a ratio of 1:1:1; 40 patients in each group. All patients received routine treatment and cardiac rehabilitation. LE group and CRT group respectively performed LE and CRT once a day for 30 min for 7 days. Control group did not receive specialized respiratory training. The forced vital capacity, forced expiratory volume in 1 s, peak inspiratory flow rate, peak expiratory flow rate, maximum inspiratory pressure, maximum expiratory pressure, modified Barthel index (MBI), and Hamilton Rating Scale for Anxiety (HAM-A) were evaluated before, after 3 and 7 days of intervention. In addition, the postoperative length of hospital stay (LOS) and the adverse events that occurred during the intervention period were compared.

RESULTS

A total of 107 patients completed the study, 120 patients were included in the analysis. After 3 days of intervention, the pulmonary function, respiratory muscle strength, MBI and HAM-A of all 3 groups improved compared with that before the intervention (P<0.05 or P<0.01). Compared with the control group, pulmonary function and respiratory muscle strength were significantly improved in the CRT and LE groups (P<0.05 or P<0.01). MBI and HAM-A were significantly improved in the LE group compared with the control and CRT groups (P<0.05 or P<0.01). On the 7th day after intervention, the difference was still statistically significant (P<0.01), and was significantly different from that on the 3rd day (P<0.05 or P<0.01). In addition, on the 7th day of intervention, the pulmonary function and respiratory muscle strength in the LE group were significantly improved compared with those in the CRT group (P<0.01). MBI and HAM-A were significantly improved in the CRT group compared with the control group (P<0.01). There were no significant differences in postoperative LOS among the 3 groups (P>0.05). No training-related adverse events occurred during the intervention period.

CONCLUSIONS

LE is safe and feasible for improving pulmonary function, respiratory muscle strength, the ability to complete activities of daily living and for relieving anxiety of patients after cardiac surgery (Registration No. ChiCTR2200062964).

Peak Work Rate Increases With Lower Extremity-Focused Exercise Training in Adolescents With Fontan Circulation

Background Skeletal muscle deficits are associated with worse exercise performance in the Fontan circulation and may be improved by exercise training. We aimed to assess the change in leg lean mass (a marker of skeletal muscle), exercise performance, and functional health status after a lower extremity-focused exercise intervention in adolescents with Fontan circulation. Methods and Results Densitometry for measurement of leg lean mass, cardiopulmonary exercise test, exercise cardiac magnetic resonance, peripheral vascular testing, physical activity questionnaire, and quality of life assessment were performed at baseline and after a 24-week, hybrid center- and home-based training program. Leg lean mass Z-scores were generated, and exercise parameters were expressed as percentage expected based on reference data. The effect of training was assessed by paired t-tests and simple linear regression. Twenty participants (15.6±1.7 years, 50% male) demonstrated low baseline leg lean mass Z-scores with no significant improvement with training (-1.38±1.02 pre versus -1.31±1.06 post, P=0.33). Maximum and percent predicted work increased from 121.9±29.8 (0.66±0.12) to 131.3±35.1 (0.70±0.15) watts (P=0.02). Peak respiratory exchange ratio increased (1.19±0.02 versus 1.25±0.01, P=0.02) but percent predicted oxygen consumption was unchanged, suggesting higher anaerobic activity after training. Physical activity questionnaire score positively associated with peak work at baseline (ß=18.13 [95% CI, 0.83-35.44], R²=0.21; P=0.04) but physical activity questionnaire, quality of life scores, exercise cardiac magnetic resonance performance, and peripheral vascular function were unchanged with training. Conclusions Peak work rate and anaerobic activity increased with lower extremity-focused training in adolescents with Fontan circulation. Larger studies should test the impact of these changes on functional status and quality of life.

Peripheral and respiratory muscle strength in children and adolescents with CHD: systematic review and meta-analysis

Patients with CHD are less active if compared with controls and have limited functional capacity, related to muscle weakness and fatigue. The aim of this study was to evaluate the peripheral and respiratory muscle strength of children and adolescents with CHD with systematic review and meta-analysis. The review included observational and randomised control trial studies which evaluated peripheral and respiratory muscle strength in children and adolescents with CHD under 18 years old. The peripheral muscle strength was evaluated through dynamometry and respiratory muscle strength through manovacuometry. In studies that compared patients with CHD and respective control groups, it was possible to perform a meta-analysis. A total of 5634 articles met the criteria of eligibility, 15 were included in the systematic review, and 4 were included in the meta-analysis. Twelve studies assessed peripheral muscle strength with a reduction in patients with CHD. In the meta-analysis, patients with CHD had lower muscle strength than controls (-34.07 nm; 95% CI, -67.46 to -0.68; I2 47%; p for heterogeneity = 0.05), and the meta-analysis of the handgrip muscle strength showed no significant difference between patients with CHD and controls (0.08 nm; 95% CI, -6.39 to 6.55; I2 98%; p for heterogeneity <0.00001). The meta-analysis in the present study  showed lower limb muscle strength in patients with CHD in comparison to controls. In contrast, no difference was found regarding hand grip strength. Also, the review showed lower respiratory muscle strength in patients with CHD, yet no meta-analysis was possible to perform.

Prediction and prognosis of reintubation after surgery for Stanford type A aortic dissection

Background

Reintubation is a serious adverse respiratory event after Stanford type A aortic dissection surgery (AADS), however, published studies focused on reintubation after AADS are very limited worldwide. The objectives of the current study were to establish an early risk prediction model for reintubation after AADS and to clarify its relationship with short-term and long-term prognosis.

Methods

Patients undergoing AADS between 2016–2019 in a single institution were identified and divided into two groups based on whether reintubation was performed. Independent predictors were identified by univariable and multivariable analysis and a clinical prediction model was then established. Internal validation was performed using bootstrap method with 1,000 replications. The relationship between reintubation and clinical outcomes was determined by univariable and propensity score matching analysis.

Results

Reintubation were performed in 72 of the 492 included patients (14.6%). Three preoperative and one intraoperative predictors for reintubation were identified by multivariable analysis, including older age, smoking history, renal insufficiency and transfusion of intraoperative red blood cells. The model established using the above four predictors showed moderate discrimination (AUC = 0.753, 95% CI, [0.695–0.811]), good calibration (Hosmer-Lemeshow χ² value = 3.282, P = 0.915) and clinical utility. Risk stratification was performed and three risk intervals were identified. Reintubation was closely associated with poorer in-hospital outcomes, however, no statistically significant association between reintubation and long-term outcomes has been observed in patients who were discharged successfully after surgery.

Conclusions

The requirement of reintubation after AADS is prevalent, closely related to adverse in-hospital outcomes, but there is no statistically significant association between reintubation and long-term outcomes. Predictors were identified and a risk model predicting reintubation was established, which may have clinical utility in early individualized risk assessment and targeted intervention.

Pneumonia After Cardiovascular Surgery: Incidence, Risk Factors and Interventions

Postoperative pneumonia (POP) is prevalent in patients undergoing cardiovascular surgery, associated with poor clinical outcomes, prolonged hospital stay and increased medical costs. This article aims to clarify the incidence, risk factors, and interventions for POP after cardiovascular surgery. A comprehensive literature search was performed to identify previous reports involving POP after cardiovascular surgery. Current situation, predictors and preventive measures on the development of POP were collected and summarized. Many studies showed that POP was prevalent in various cardiovascular surgical types, and predictors varied in different studies, including advanced age, smoking, chronic lung disease, chronic kidney disease, cardiac surgery history, cardiac function, anemia, body mass index, diabetes mellitus, surgical types, cardiopulmonary bypass time, blood transfusion, duration of mechanical ventilation, repeated endotracheal intubation, and some other risk factors. At the same time, several targeted interventions have been widely reported to be effective to reduce the risk of POP and improve prognosis, including preoperative respiratory physiotherapy, oral care and subglottic secretion drainage. Through the review of the current status, risk factors and intervention measures, this article may play an important role in clinical prevention and treatment of POP after cardiovascular surgery.

Exercise Training for People Living with a Fontan Circulation: An Underutilized Intervention

Surgical repair for children born with single ventricle congenital heart disease, culminating in the Fontan operation, has resulted in dramatic improvements in survival; children born with these lesions are now typically expected to survive well into adulthood. Most, but not all, individuals with a Fontan circulation have reduced exercise capacity compared with the general population that in turn is associated with increased cardiovascular morbidity and mortality. The cause of reduced exercise capacity is multifactorial. A significant contributor is the absence of a subpulmonary ventricular pump, which limits preload and appropriate cardiac output augmentation to meet the increased metabolic demands that occur with exercise. While in its infancy relative to adults with acquired heart disease, the evidence to date suggests that exercise interventions to improve exercise capacity and Fontan physiology in children and adults with Fontan circulation are safe, effective and well tolerated. However, many knowledge gaps remain, including a detailed understanding of the unique physiological adaptations that occur, the optimal approach to exercise in this population and the effectiveness of home-based interventions utilizing telemedicine and remote physiologic monitoring technologies. Furthermore, the long-term impact of such interventions on the Fontan-cardiovascular system, physical activity levels, health-related quality of life, and late cardiovascular morbidity and mortality are not well characterized. In this review, we outline the factors associated with reduced exercise capacity in individuals with Fontan circulation, review the experience to date of dedicated interventions to improve exercise capacity, and highlight the current knowledge gaps in the field and priorities for further study.

Endurance training may improve exercise capacity, lung function and quality of life in Fontan patients

Children born with univentricular hearts undergo staged surgical procedures to a Fontan circulation. Long-term experience with Fontan palliation has shown dramatically improved survival but also of a life-long burden of an abnormal circulation with significant morbidity. Many Fontan patients have reduced exercise capacity, oxygen uptake, lung function and quality of life. Endurance training may improve submaximal, but not maximal, exercise capacity, lung function and quality of life. Physical activity and endurance training is also positively correlated with sleep quality. Reviewing the literature and from our single-centre experience, we believe there is enough evidence to support structured individualised endurance training in most young Fontan patients.

Impairments in Pulmonary Function in Fontan Patients: Their Causes and Consequences

Patients with a Fontan circulation lack a sub-pulmonary ventricle with pulmonary blood flow passively redirected to the lungs. In the Fontan circulation, ventilation has a significant influence on pulmonary blood flow and cardiac output both at rest and with exercise. Children and adults with a Fontan circulation have abnormalities in lung function. In particular, restrictive ventilatory patterns, as measured by spirometry, and impaired gas transfer, as measured by the diffusing capacity of carbon monoxide, have been frequently observed. These abnormalities in lung function are associated with reduced exercise capacity and quality of life. Moderate to severe impairment in lung volumes is independently associated with reduced survival in adults with congenital heart disease. Skeletal and inspiratory muscle weakness has also been reported in patients with a Fontan circulation, with the prospect of improving respiratory muscle function through exercise training programs. In this review, we will present data on cardiopulmonary interactions in the Fontan circulation, the prevalence and severity of impaired lung function, and respiratory muscle function in this population. We will discuss potential causes for and consequence of respiratory impairments, and their impact on exercise capacity and longer-term Fontan outcome. We aim to shed light on possible strategies to reduce morbidity by improving respiratory function in this growing population of patients.

Exercise capacity after total cavopulmonary anastomosis: a longitudinal paediatric and adult study

AIMS

Fontan palliation is a surgical strategy for patients with complex congenital heart disease, in whom biventricular circulation cannot be achieved. Long-term survival is negatively affected by the absence of sub-pulmonary ventricle and increased systemic venous pressure. Exercise capacity is a known predictor of overall survival and quality of life in congenital heart defects. We aim to track individual trends of peak oxygen uptake (V̇O₂ peak) after total cavopulmonary connection (TCPC), identify predictors of deterioration, and derive a disease-specific reference V̇O₂ peak dataset.

METHODS AND RESULTS

A retrospective study of serial cardiopulmonary exercise testing (CPET) data, gathered from all patients who underwent TCPC in the Czech Republic between 1992 and 2016. Of 354 consecutive patients with TCPC, 288 (81.4%) patients underwent one or more CPETs yielding 786 unique V̇O₂ peak values used as a reference dataset. Longitudinal data were available in 206 (58.2%) patients, who underwent a median (inter-quartile range) of 3.0 (2.0-5.0) CPETs over a mean (standard deviation) of 8.9 (5.5) years. The decline of exercise capacity with age was linear and not faster than in healthy peers (P = 0.47), but relative values of V̇O₂ peak in TCPC patients were 12.6 mL/min/kg lower. Single ventricular morphology and pulmonary artery size had no significant influence on the exercise capacity dynamics. V̇O₂ peak decline correlated negatively with the trend of body mass index z-score (P = 0.006) and was faster in women than men (P = 0.008).

CONCLUSIONS

Total cavopulmonary connection patients have significantly reduced exercise capacity. The age-related decline paralleled the healthy population and correlated negatively with the body mass index trend. The presented V̇O₂ peak reference dataset may help the clinicians to grade the severity of exercise capacity impairment in individual TCPC patients.

Exercise Intolerance, Benefits, and Prescription for People Living With a Fontan Circulation: The Fontan Fitness Intervention Trial (F-FIT)-Rationale and Design

Background: Despite developments in surgical techniques and medical care, people with a Fontan circulation still experience long-term complications; non-invasive therapies to optimize the circulation have not been established. Exercise intolerance affects the majority of the population and is associated with worse prognosis. Historically, people living with a Fontan circulation were advised to avoid physical activity, but a small number of heterogenous, predominantly uncontrolled studies have shown that exercise training is safe-and for unique reasons, may even be of heightened importance in the setting of Fontan physiology. The mechanisms underlying improvements in aerobic exercise capacity and the effects of exercise training on circulatory and end-organ function remain incompletely understood. Furthermore, the optimal methods of exercise prescription are poorly characterized. This highlights the need for large, well-designed, multi-center, randomized, controlled trials. Aims and Methods: The Fontan Fitness Intervention Trial (F-FIT)-a phase III clinical trial-aims to optimize exercise prescription and delivery in people with a Fontan circulation. In this multi-center, randomized, controlled study, eligible Fontan participants will be randomized to either a 4-month supervised aerobic and resistance exercise training program of moderate-to-vigorous intensity followed by an 8-month maintenance phase; or usual care (control group). Adolescent and adult (≥16 years) Fontan participants will be randomized to either traditional face-to-face exercise training, telehealth exercise training, or usual care in a three-arm trial with an allocation of 2:2:1 (traditional:telehealth:control). Children (<16 years) will be randomized to either a physical activity and exercise program of moderate-to-vigorous intensity or usual care in a two-arm trial with a 1:1 allocation. The primary outcome is a change in aerobic exercise capacity (peak oxygen uptake) at 4-months. Secondary outcomes include safety, and changes in cardiopulmonary exercise testing measures, peripheral venous pressure, respiratory muscle and lung function, body composition, liver stiffness, neuropsychological and neurocognitive function, physical activity levels, dietary and nutritional status, vascular function, neurohormonal activation, metabolites, cardiac function, quality of life, musculoskeletal fitness, and health care utilization. Outcome measures will be assessed at baseline, 4-months, and 12-months. This manuscript will describe the pathophysiology of exercise intolerance in the Fontan circulation and the rationale and protocol for the F-FIT.