Exercise Intolerance in Adult Congenital Heart Disease

Surveillance of adults with congenital heart disease: Current guidelines and actual clinical practice

BACKGROUND AND AIM

Congenital heart disease (CHD) is the most common birth defect with prevalence of 0.8%. Thanks to tremendous progress in medical and surgical practice, nowadays, >90% of children survive into adulthood. Recently European Society of Cardiology (ESC), American College of Cardiology (ACC)/ American Heart Association (AHA) issued guidelines which offer diagnostic and therapeutic recommendations for the different defect categories. However, the type of technical exams and their frequency of follow-up may vary largely between clinicians and centres. We aimed to present an overview of available diagnostic modalities and describe current surveillance practices by cardiologists taking care of adults with CHD (ACHD).

METHODS AND RESULTS

A questionnaire was used to assess the frequency cardiologists treating ACHD for at least one year administrated the most common diagnostic tests for ACHD. The most frequently employed diagnostic modalities were ECG and echocardiography for both mild and moderate/severe CHD. Sixty-seven percent of respondents reported that they routinely address psychosocial well-being.

CONCLUSION

Differences exist between reported current clinical practice and published guidelines. This is particularly true for the care of patients with mild lesions. In addition, some differences exist between ESC and American guidelines, with more frequent surveillance suggested by the Americans.

Predicting the effects of surgically determined parameters on exercise tolerance in Fontan patients

The Fontan physiology is a surgically created circulation for patients with a single functioning ventricle. Patients with this circulation tend to have lower exercise tolerance compared to those with a normal circulation. Important computational and experimental work has been done to investigate this reduction in exercise tolerance. However, there are few systematic modeling studies that focus on the effect of several surgically determined parameters within the same framework. We propose a mathematical model to describe the Fontan circulation under exercise. We then formulate a heuristic based on clinical data from Fontan patients to estimate exercise tolerance. The model is used to investigate the effect of three important surgically determined parameters on exercise tolerance: the systemic arterial compliance, the systemic-venous to pulmonary-venous fenestration, and the resistance of the total cavopulmonary connection.

B-type natriuretic peptide levels predict long-term mortality in a large cohort of adults with congenital heart disease

BACKGROUND AND AIMS

Many adult patients with congenital heart disease (ACHD) are still afflicted by premature death. Previous reports suggested natriuretic peptides may identify ACHD patients with adverse outcome. The study investigated prognostic power of B-type natriuretic peptide (BNP) across the spectrum of ACHD in a large contemporary cohort.

METHODS

The cohort included 3392 consecutive ACHD patients under long-term follow-up at a tertiary ACHD centre between 2006 and 2019. The primary study endpoint was all-cause mortality.

RESULTS

A total of 11 974 BNP measurements were analysed. The median BNP at baseline was 47 (24-107) ng/L. During a median follow-up of 8.6 years (29 115 patient-years), 615 (18.1%) patients died. On univariable and multivariable analysis, baseline BNP [hazard ratio (HR) 1.16, 95% confidence interval (CI) 1.15-1.18 and HR 1.13, 95% CI 1.08-1.18, respectively] and temporal changes in BNP levels (HR 1.22, 95% CI 1.19-1.26 and HR 1.19, 95% CI 1.12-1.26, respectively) were predictive of mortality (P < .001 for both) independently of congenital heart disease diagnosis, complexity, anatomic/haemodynamic features, and/or systolic systemic ventricular function. Patients within the highest quartile of baseline BNP (>107 ng/L) and those within the highest quartile of temporal BNP change (>35 ng/L) had significantly increased risk of death (HR 5.8, 95% CI 4.91-6.79, P < .001, and HR 3.6, 95% CI 2.93-4.40, P < .001, respectively).

CONCLUSIONS

Baseline BNP and temporal BNP changes are both significantly associated with all-cause mortality in ACHD independent of congenital heart disease diagnosis, complexity, anatomic/haemodynamic features, and/or systolic systemic ventricular function. B-type natriuretic peptide levels represent an easy to obtain and inexpensive marker conveying prognostic information and should be used for the routine surveillance of patients with ACHD.

Repaired Tetralogy of Fallot: Have We Understood the Right Timing of PVR?

Despite many advances in surgical repair during the past few decades, the majority of tetralogy of Fallot patients continue to experience residual hemodynamic and electrophysiological abnormalities. The actual issue, which has yet to be solved, is understanding how this disease evolves in each individual patient and, as a result, who is truly at risk of sudden death, as well as the proper timing of pulmonary valve replacement (PVR). Our responsibility should be to select the most appropriate time for each patient, going above and beyond imaging criteria used up to now to make such a clinically crucial decision. Despite several studies on timing, indications, procedures, and outcomes of PVR, there is still much uncertainty about whether PVR reduces arrhythmia burden or improves survival in these patients and how to appropriately manage this population. This review summarizes the most recent research on the evolution of repaired tetralogy of Fallot (from adolescence onwards) and risk factor variables that may favor or delay PVR.

The effects of telerehabilitation in adults with complex biventricular congenital heart conditions: protocol for a multi-centre, randomised controlled trial-CH-FIT

BACKGROUND

Accumulated evidence suggests that exercise training exerts beneficial effects on people with congenital heart conditions. These findings are predominantly derived from small, single-centre exercise trials conducted in outpatient rehabilitation facilities. In recent years, the delivery of exercise interventions remotely has increased through digital communications technology (telerehabilitation). However, very little research to date has been conducted into the efficacy of telerehabilitation in people with a congenital heart condition.

AIMS

To evaluate the effects of a telehealth-delivered exercise intervention in people with a history of a surgical biventricular repair due to a congenital heart condition.

METHODS

One hundred eligible adolescent (≥ 16 years) and adult participants living with a complex biventricular congenital heart condition will be recruited from four Australian sites and randomised to either (1) a 16-week telehealth-delivered combined (aerobic and resistance) exercise training programme of moderate-to-vigorous intensity or (2) usual care (control group), in a 1:1 allocation, with an 8-month follow-up.

OUTCOMES OF INTEREST

The primary outcome will be the change in aerobic capacity expressed as peak oxygen uptake (VO2peak). Secondary outcomes will include changes in vascular function, muscle oxygenation, metabolic profile, body composition and musculoskeletal fitness, neurohormonal activation, neurocognitive function, physical activity levels, dietary and nutritional status, and quality of life. Outcomes will be assessed at baseline, 16 weeks, and 12 months (to determine longer-term maintenance potential).

DISCUSSION

If found to be efficacious, telerehabilitation may be an alternative option for delivering exercise, improving health outcomes, and increasing accessibility to exercise programmes. Efficacy data is required to quantify the clinical significance of this delivery mode of exercise.

TRIAL REGISTRATION

ACTRN12622000050752 Trial registration date: 17 January 2022 Trial registration URL: https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=382635&showOriginal=true&isReview=true Trial registry name: Australian and New Zealand Clinical Trials Registry.

Adults with Congenital Heart Disease and Transplant: Challenges, Opportunities, and Policy

The rate of heart transplantation in adults with congenital heart disease (ACHD) is rising, but the 1-year mortality posttransplantation remains higher than non-ACHD patients. A robust pretransplant assessment and operative and postoperative planning can mitigate much of the perioperative risk. Importantly, ACHD patients who survive the first year have significantly better 10-year survival compared with non-ACHD patients. The current allocation system gives ACHD patients a relatively high priority, but providers must use the prespecified exception requests for higher status, especially for patients with the Fontan circulation. It is vital that ACHD patients with end-stage heart failure are cared for at centers with ACHD subspecialty care.

Development and Initial Validation of a Frailty Score for Pediatric Patients with Congenital and Acquired Heart Disease

Frailty is a multi-dimensional clinical syndrome that is associated with increased morbidity and mortality and decreased quality of life. Children/adolescents with heart disease (HD) perform significantly worse for each frailty domain compared to non-HD peers. Our study aimed to create a composite frailty score (CFS) that can be applied to children/adolescents with HD and evaluate associations between the CFS and outcomes. Children and adolescents (n = 30) with HD (73% single ventricle, 20% heart failure, 7% pulmonary hypertension) were recruited from 2016 to 2017 (baseline). Five frailty domains were assessed at baseline using measures validated for pediatrics: (1) Slowness: 6-min walk test; (2) Weakness: handgrip strength; (3) Fatigue: PedsQL Multi-dimensional Fatigue Scale; (4) Body composition: triceps skinfold thickness; and (5) Physical activity questionnaire. Frailty points per domain (range = 0-5) were assigned based on z-scores or raw questionnaire scores and summed to produce a CFS (0 = least frail; 25 = most frail). Nonparametric bootstrapping was used to identify correlations between CFS and cross-sectional change in outcomes over 2.2 ± 0.2 years. The mean CFS was 12.5 ± 3.5. In cross-sectional analyses of baseline data, correlations (|r|≥ 0.30) were observed between CFS and NYHA class, the number of ancillary specialists, total prescribed medications, heart failure medications/day, exercise test derived chronotropic index and percent predicted VO2peak, and between child and parent proxy PEDsQL. At follow-up, CFS was correlated with an increase in the number of heart failure medications (r = 0.31). CFS was associated with cross-sectional outcomes in youth with heart disease. Longitudinal analyses were limited by small sample sizes due to loss to follow-up.

Medical Therapy and Monitoring in Adult Congenital Heart Disease Heart Failure

Heart failure (HF) in adult congenital heart disease (ACHD) is an increasingly common problem facing ACHD and advanced heart disease and transplant providers. Patients are highly nuanced, and therapies are poorly studied. Standard HF medications are often used in patients who are not targets of large clinical trials. HF management in this data-free zone requires focused, comprehensive team-based care and close follow-up and communication with patients.

Long-term effects of physical training on cardiopulmonary exercise parameters in young patients with congenital heart diseases

INTRODUCTION

Physical activity is recognised as an important intervention in patients with CHD. However, more data on the actual magnitude of physical training impact on functional capacity in this group of patients are still warranted. We aim to assess effort tolerance in a contemporary cohort of patients with congenital heart disease, regularly following a training programme, in comparison with a matched control group.

METHODS

Patients with CHD followed at the sports medicine department, who had undergone cardiopulmonary exercise test between 2011 and 2019, were included. Variables recorded were maximum workload, absolute and indexed maximum oxygen consumption, maximum heart rate, absolute and indexed maximum O2 pulse, ventilatory equivalent of CO2 and oxygen consumption/Work. Trend of cardiopulmonary parameters was analysed over time. Maximal workload, maximum oxygen consumption and ventilatory equivalent of CO2 were compared with a control group of patients with a more sedentary lifestyle, matched for diagnosis, gender, age, and body mass index.

RESULTS

Among one hundred and eleven patients, 73 males (66%) were analysed. Median age was 14 (12-17) years. Twenty-nine patients (27%) were practising sports at competitive level. Maximum oxygen consumption and oxygen consumption % of maximum predicted were not significantly different at follow-up as compared with baseline. Follow-up of maximum oxygen consumption was 38.2 ± 9 ml/kg/min versus 38.6 ± 9.2 ml/kg/min (p = NS) and follow-up of %oxygen consumption was 88 ± 20 versus 87 ± 15 (p = NS). Ventilatory equivalent of CO2 significantly improved in the last test as compared with the baseline: 30 ± 4 versus 33 ± 5 (p = 0.002). As compared with the control group, trained patients displayed a significantly higher maximum workload and oxygen consumption, while ventilatory equivalent of CO2 was not significantly different.

CONCLUSIONS

In our cohort, patients following a regular training programme displayed a significantly higher functional capacity as compared with not trained control group, irrespective of NYHA class. Objective functional capacity was stable over a median follow-up of 3 years.

Hemodynamic Melody of Postnatal Cardiac and Pulmonary Development in Children with Congenital Heart Diseases

Hemodynamics is the eternal theme of the circulatory system. Abnormal hemodynamics and cardiac and pulmonary development intertwine to form the most important features of children with congenital heart diseases (CHDs), thus determining these children's long-term quality of life. Here, we review the varieties of hemodynamic abnormalities that exist in children with CHDs, the recently developed neonatal rodent models of CHDs, and the inspirations these models have brought us in the areas of cardiomyocyte proliferation and maturation, as well as in alveolar development. Furthermore, current limitations, future directions, and clinical decision making based on these inspirations are highlighted. Understanding how CHD-associated hemodynamic scenarios shape postnatal heart and lung development may provide a novel path to improving the long-term quality of life of children with CHDs, transplantation of stem cell-derived cardiomyocytes, and cardiac regeneration.

A surgical mouse model of neonatal right ventricular outflow tract obstruction by pulmonary artery banding

BACKGROUD

Diseased animal models play an extremely important role in preclinical research. Lacking the corresponding animal models, many basic research studies cannot be carried out, and the conclusions obtained are incomplete or even incorrect. Right ventricular (RV) outflow tract (RVOT) obstruction leads to RV pressure overload (PO) and reduced pulmonary blood flow (RPF), which are 2 of the most important pathophysiological characteristics in pediatric cardiovascular diseases and seriously affect the survival rate and long-term quality of life of many children. Due to the lack of a neonatal mouse model for RVOT obstruction, it is largely unknown how RV PO and RPF regulate postnatal RV and pulmonary development. The aim of this study was to construct a neonatal RVOT obstruction mouse model.

METHODS AND RESULTS

Here, we first introduced a neonatal mouse model of RVOT obstruction by pulmonary artery banding (PAB) on postnatal day 1. PAB induced neonatal RVOT obstruction, RV PO, and RPF. Neonatal RV PO induced cardiomyocyte proliferation, and neonatal RPF induced pulmonary dysplasia, the 2 features that are not observed in adult RVOT obstruction. As a result, PAB neonates exhibited overall developmental dysplasia, a sign similar to that of children with RVOT obstruction.

CONCLUSIONS

Because many pediatric cardiovascular diseases are associated with RV PO and RPF, the introduction of a neonatal mouse model of RVOT obstruction may greatly enhance our understanding of these diseases and eventually improve or save the lives of many children.

How to interpret a cardiorespiratory fitness assessment - Key measures that provide the best picture of health, disease status and prognosis

Graded exercise testing is a widely accepted tool for revealing cardiac ischemia and/or arrhythmias in clinical settings. Cardiopulmonary exercise testing (CPET) measures expired gases during a graded exercise test making it a versatile tool that helps reveal underlying physiologic abnormalities that are in many cases only present with exertion. It also characterizes one's health status and clinical trajectory, informs the therapeutic plan, evaluates the efficacy of therapy, and provides submaximal and maximal information that can be used to tailor an exercise intervention. Practitioners can also modify the mode and protocol to allow individuals of all ages, fitness levels, and most disease states to perform a CPET. When used to its full potential, CPET can be a key tool used to optimize care in primary and secondary prevention settings.

Cardiopulmonary Exercise Testing after Surgical Repair of Tetralogy of Fallot-Does Modality Matter?

BACKGROUND

Despite a successful repair of tetralogy of Fallot (rToF) in childhood, residual lesions are common and can contribute to impaired exercise capacity. Although both cycle ergometer and treadmill protocols are often used interchangeably these approaches have not been directly compared. In this study we examined cardiopulmonary exercise test (CPET) measurements in rToF.

METHODS

Inclusion criteria were clinically stable rToF patients able to perform a cardiac magnetic resonance imaging (CMR) and two CPET studies, one on the treadmill (incremental Bruce protocol) and one on the cycle ergometer (ramped protocol), within 12 months. Demographic, surgical and clinical data; functional class; QRS duration; CMR measures; CPET data and international physical activity questionnaire (IPAQ) scores of patients were collected.

RESULTS

Fifty-seven patients were enrolled (53% male, 20.5 ± 7.8 years at CPET). CMR measurements included a right ventricle (RV) end-diastolic volume index of 119 ± 22 mL/m2, a RV ejection fraction (EF) of 55 ± 6% and a left ventricular (LV) EF of 56 ± 5%. Peak oxygen consumption (VO2)/Kg (25.5 ± 5.5 vs. 31.7 ± 6.9; p < 0.0001), VO2 at anaerobic threshold (AT) (15.3 ± 3.9 vs. 22.0 ± 4.5; p < 0.0001), peak O2 pulse (10.6 ± 3.0 vs. 12.1± 3.4; p = 0.0061) and oxygen uptake efficiency slope (OUES) (1932.2 ± 623.6 vs. 2292.0 ± 639.4; p < 0.001) were significantly lower on the cycle ergometer compared with the treadmill, differently from ventilatory efficiency (VE/VCO2) max which was significantly higher on the cycle ergometer (32.2 ± 4.5 vs. 30.4 ± 5.4; p < 0.001). Only the VE/VCO2 slope at the respiratory compensation point (RCP) was similar between the two methodologies (p = 0.150).

CONCLUSIONS

The majority of CPET measurements differed according to the modality of testing, with the exception being the VE/VCO2 slope at RCP. Our data suggest that CPET parameters should be interpreted according to test type; however, these findings should be validated in larger populations and in a variety of institutions.

Peak oxygen consumption by smartwatches compared with cardiopulmonary exercise test in complex congenital heart disease

OBJECTIVE

To evaluate for correlation between exercise capacity as assessed by peak oxygen consumption (pVO2) measurement during a cardiopulmonary exercise test (CPET) and smartwatches reporting this parameter in patients with adult congenital heart disease (ACHD) complex lesions.

METHODS

A prospective study that included patients with ACHD either a Fontan circulation or a right ventricle supporting the systemic circulation who underwent two separate CPETs at least 1 year apart. Generalised estimating equations linear regression was performed to identify factors associated with correlation between smartwatch and CPET-derived pVO2.

RESULTS

48 patients (71% with a Fontan circulation, 42% females, mean age 33±9 years) underwent two CPETs between May 2018 and May 2022 with echocardiograms performed within 6 months of each CPET. Apple Watch was the predominant smartwatch used (79%). Smartwatch and CPET measured peak heart rate (Pearson correlation=0.932, 95% CI (0.899, 0.954)) and pVO2 (0.8627, 95% CI (0.8007, 0.9064) and 0.8634, 95% CI (0.7676, 0.9215) in the first and second CPET, respectively) correlated well, with smartwatch-measured pVO2 values measuring higher by a mean of 3.146 mL/kg/min (95% CI (2.559, 3.732)). Changes in pVO2 between the first and the second CPET also correlated well (Pearson correlation=0.9165, 95% CI (0.8549, 0.9525)), indicating that for every 1 mL/(min kg) change in CPET-measured pVO2, there was a corresponding 0.896 mL/(min kg) change in the smartwatch-measured pVO2.

CONCLUSION

Both absolute values and changes over time in pVO2 as measured by smartwatches and CPETs correlate well in patients with complex ACHD.

Adherence to clinical practice guidelines for pulmonary valve intervention after tetralogy of Fallot repair: A nationwide cohort study

Objectives

To determine guideline adherence pertaining to pulmonary valve replacement (PVR) referral after tetralogy of Fallot (TOF) repair.

Methods

Children and adults with cardiovascular magnetic resonance imaging scans and at least moderate pulmonary regurgitation were prospectively enrolled in the Comprehensive Outcomes Registry Late After TOF Repair (CORRELATE). Individuals with previous PVR were excluded. Patients were classified according to presence (+) versus absence (-) of PVR and presence (+) versus absence (-) of contemporaneous guideline satisfaction. A validated score (specific activity scale [SAS]) classified adult symptom status.

Results

In total, 498 participants (57% male, mean age 32 ± 14 years) were enrolled from 14 Canadian centers (2013-2020). Mean follow-up was 3.8 ± 1.8 years. Guideline criteria for PVR were satisfied for the majority (n = 422/498, 85%), although referral for PVR occurred only in a minority (n = 167/498, 34%). At PVR referral, most were asymptomatic (75% in SAS class 1). One participant (0.6%) received PVR without meeting criteria (PVR+/indication-). The remainder (n = 75/498, 15%) did not meet criteria for and did not receive PVR (PVR-/indication-). Abnormal cardiovascular imaging was the most commonly cited indication for PVR (n = 61/123, 50%). The SAS class and ratio of right to left end-diastolic volumes were independent predictors of PVR in a multivariable analysis (hazard ratio, 3.33; 95% confidence interval, 1.92-5.8, P < .0001; hazard ratio, 2.78; 95% confidence interval, 2.18-3.55, P < .0001).

Conclusions

Although a majority of patients met guideline criteria for PVR, only a minority were referred for intervention. Abnormal cardiovascular imaging was the most common indication for referral. Further research will be necessary to establish the longer-term clinical impact of varying PVR referral strategies.

Deep learned representations of the resting 12-lead electrocardiogram to predict at peak exercise

AIMS

To leverage deep learning on the resting 12-lead electrocardiogram (ECG) to estimate peak oxygen consumption (V˙O2peak) without cardiopulmonary exercise testing (CPET).

METHODS AND RESULTS

V ˙ O 2 peak estimation models were developed in 1891 individuals undergoing CPET at Massachusetts General Hospital (age 45 ± 19 years, 38% female) and validated in a separate test set (MGH Test, n = 448) and external sample (BWH Test, n = 1076). Three penalized linear models were compared: (i) age, sex, and body mass index ('Basic'), (ii) Basic plus standard ECG measurements ('Basic + ECG Parameters'), and (iii) basic plus 320 deep learning-derived ECG variables instead of ECG measurements ('Deep ECG-V˙O2'). Associations between estimated V˙O2peak and incident disease were assessed using proportional hazards models within 84 718 primary care patients without CPET. Inference ECGs preceded CPET by 7 days (median, interquartile range 27-0 days). Among models, Deep ECG-V˙O2 was most accurate in MGH Test [r = 0.845, 95% confidence interval (CI) 0.817-0.870; mean absolute error (MAE) 5.84, 95% CI 5.39-6.29] and BWH Test (r = 0.552, 95% CI 0.509-0.592, MAE 6.49, 95% CI 6.21-6.67). Deep ECG-V˙O2 also outperformed the Wasserman, Jones, and FRIEND reference equations (P < 0.01 for comparisons of correlation). Performance was higher in BWH Test when individuals with heart failure (HF) were excluded (r = 0.628, 95% CI 0.567-0.682; MAE 5.97, 95% CI 5.57-6.37). Deep ECG-V˙O2 estimated V˙O2peak <14 mL/kg/min was associated with increased risks of incident atrial fibrillation [hazard ratio 1.36 (95% CI 1.21-1.54)], myocardial infarction [1.21 (1.02-1.45)], HF [1.67 (1.49-1.88)], and death [1.84 (1.68-2.03)].

CONCLUSION

Deep learning-enabled analysis of the resting 12-lead ECG can estimate exercise capacity (V˙O2peak) at scale to enable efficient cardiovascular risk stratification.

Aortic arch shape after arch repair predicts exercise capacity: a multicentre analysis

Aims

Coarctation of the aorta is associated with long-term morbidity including decreased exercise capacity, despite successful repair. In the absence of discrete recoarctation, the haemodynamic mechanism remains unknown. This multicentre study evaluated the relationship between aorta shape, flow, and exercise capacity in patients after arch repair, specifically through the lens of aortic size mismatch and descending aortic (DAo) flow and their association with exercise.

Methods and results

Cardiac magnetic resonance, cardiopulmonary exercise test, and echocardiogram data within 1 year were analysed from 58 patients (age 28 ± 10 years, 48% male) across four centres with history of isolated arch repair. Aortic arch measurements were correlated with % predicted VO2max with subgroup analyses of those with residual arch obstruction, bicuspid aortic valve, and hypertension. Ascending aorta (AAo) to DAo diameter ratio (DAAo/DDAo) was negatively correlated with % predicted VO2max. %DAo flow positively correlated with VO2max. Sub-analyses demonstrated that the negative correlation of DAAo/DDAo with VO2max was maintained only in patients without arch obstruction and with a bicuspid aortic valve. Smaller aortic arch measurements were associated with both hypertension and exercise-induced hypertension.

Conclusion

Aorta size mismatch, due to AAo dilation or small DAo, and associated decreased %DAo flow, correlated significantly with decreased exercise capacity after aortic arch repair. These correlations were stronger in patients without arch obstruction and with a bicuspid aortic valve. Aorta size mismatch and %DAo flow capture multiple mechanisms of altered haemodynamics beyond blood pressure gradient or discrete obstruction and can inform the definition of a successful repair.

Management of Junctional Rhythm in Patients After the Fontan Operation: A Multicenter Congenital Cardiology Survey

Sinus node dysfunction with concomitant junctional rhythm (JR) is frequently observed among Fontan patients and has been recognized as a contributor to heart failure. The impact and management of JR is unclear. A survey was mailed to all members of the Pediatric and Congenital Electrophysiology society (PACES) and members were asked to forward the questionnaire to their non-electrophysiology colleagues. Responses were received from 154 physicians (88 electrophysiologists (EP's) and 66 non-EP's (46 pediatric cardiologists and 20 adult congenital cardiologists). There were few differences in the response between EP's and non-EP's. Overall, 57% recommended an annual ambulatory ECG (AECG). A significant majority (80%) opted to continue to follow patients with significant periods of JR on AECG as long as the patients were asymptomatic, and showed no echocardiographic signs of cardiac decompensation. However, 84% would place a pacemaker in a patient with JR who was having open chest surgery for other reasons. Finally, pacemaker placement would be performed by 91% if a patient with JR showed signs of heart failure. Most congenital cardiologists would not recommend pacemaker placement in asymptomatic Fontan patients with JR. Further studies are needed on the Fontan population to determine the impact of SND and JR on longer term outcomes and to determine the role and optimal timing of pacemaker placement in these patients.

Current Management and Future Directions for Pulmonary Arterial Hypertension Associated with Congenital Heart Disease

Current management of patients with congenital heart disease has increased their survival into adulthood. This is accompanied by potential cardiac complications, including pulmonary hypertension associated with congenital heart disease (PAH-CHD). PAH-CHD constitutes a challenging subgroup of pulmonary hypertension and requires expert management to improve quality of life and prognosis. Novel agents have shown a significant improvement in morbidity and mortality in patients with pulmonary arterial hypertension. However, the long-term effects of these medications on PAH-CHD patients remain somewhat uncertain, necessitating treatment plans largely founded on the clinical experience of the healthcare providers. The aim of this review is to summarize the current evidence and future perspectives regarding treatment strategies for PAH-CHD to help better guide management of this complex disease.

The Fontan Udenafil Exercise Longitudinal Trial: Subgroup Analysis

The Pediatric Heart Network's Fontan Udenafil Exercise Longitudinal (FUEL) Trial (Mezzion Pharma Co. Ltd., NCT02741115) demonstrated improvements in some measures of exercise capacity and in the myocardial performance index following 6 months of treatment with udenafil (87.5 mg twice daily). In this post hoc analysis, we evaluate whether subgroups within the population experienced a differential effect on exercise performance in response to treatment. The effect of udenafil on exercise was evaluated within subgroups defined by baseline characteristics, including peak oxygen consumption (VO2), serum brain-type natriuretic peptide level, weight, race, gender, and ventricular morphology. Differences among subgroups were evaluated using ANCOVA modeling with fixed factors for treatment arm and subgroup and the interaction between treatment arm and subgroup. Within-subgroup analyses demonstrated trends toward quantitative improvements in peak VO2, work rate at the ventilatory anaerobic threshold (VAT), VO2 at VAT, and ventilatory efficiency (VE/VCO2) for those randomized to udenafil compared to placebo in nearly all subgroups. There was no identified differential response to udenafil based on baseline peak VO2, baseline BNP level, weight, race and ethnicity, gender, or ventricular morphology, although participants in the lowest tertile of baseline peak VO2 trended toward larger improvements. The absence of a differential response across subgroups in response to treatment with udenafil suggests that the treatment benefit may not be restricted to specific sub-populations. Further work is warranted to confirm the potential benefit of udenafil and to evaluate the long-term tolerability and safety of treatment and to determine the impact of udenafil on the development of other morbidities related to the Fontan circulation.Trial Registration NCT0274115.

Impact of pulsatile pulmonary blood flow on cardiopulmonary exercise performance after the Fontan procedure

Objective

To evaluate the exercise capacity in patients following Fontan-Kreutzer, Fontan-Björk, and total cavopulmonary connection (TCPC).

Methods

Patients who performed exercise capacity tests at least once after the Fontan procedure between 1979 and 2007 were included. Patients after Fontan-Björk procedure were divided into 2 groups according to the pulmonary blood flow (PBF) pattern: patients with pulsatile PBF and those without. Peak oxygen uptake (VO2) was measured and percent-predicted VO2 was calculated.

Results

A total of 227 patients were nominated. The types of Fontan procedure included Fontan-Kreutzer in 48 (21.1%) patients, Fontan-Björk in 38 (16.7%); 11 (4.8%) with pulsatile PBF and 27 (11.9%) without pulsatile PBF; and TCPC in 141 (62.1%). Median age at the Fontan procedure was 4.5 years (interquartile range, 2.1-8.2 years). A total of 978 cardiopulmonary exercise tests were performed at median follow-up of 17.7 years (interquartile range, 11.3-23.4 years) postoperatively. Analysis using linear mixed-effects models demonstrated that percent-predicted VO2 was greater in patients with pulsatile PBF after Fontan-Björk compared with patients after other types of Fontan procedure (P < .001). The same results were obtained when the longitudinal percent predicted VO2 was performed using only patients with tricuspid atresia and double inlet left ventricle (P < .001).

Conclusions

Among long-term survivors after various types of Fontan procedures, patients with pulsatile PBF after the Fontan-Björk procedure demonstrated better exercise performance compared to those after TCPC, those after the Fontan-Kreutzer procedure, and those after the Fontan-Björk procedure with non-pulsatile PBF. The results implicate the importance of pulsatile PBF to maintain the Fontan circulation.

The Role of Cardiopulmonary Testing to Risk Stratify Tetralogy of Fallot Patients

Neonatal repair has completely changed the clinical history of patients with tetralogy of Fallot (ToF); however, these patients carry a significant risk of severe arrhythmias and sudden cardiac death in the long term. The exact mechanism for late sudden cardiac death is multifactorial and still not well defined, and the risk stratification for primary prophylaxis in these patients remains challenging. Cardiopulmonary exercise testing (CPET) is a well-established and safe method to assess cardiopulmonary function in children and adults with congenital heart disease. Several parameters obtained with CPET have been identified as potential prognostic of major adverse cardiovascular events in congenital heart disease. CPET is routinely used to assess functional capacity also in patients with ToF, and there is some evidence showing its usefulness in predicting the cardiac adverse events in patients with repaired ToF. Current guidelines recognize the importance of CPET in the evaluation and management of patients with ToF, but there is no clear consensus on which the CPET parameter or level of exercise intolerance, as measured by CPET, is truly predictive of an increased risk of arrhythmia and major adverse cardiovascular events in this population. Therefore, the aim of this narrative review is to describe the current evidence on the potential use of CPET in the risk stratification of patients with repaired ToF.

Techniques for Cardiac Resynchronization Therapy in Patients with Congenital Heart Disease

Cardiac resynchronization therapy (CRT) for congenital heart disease has shown promising suucess as an adjunct to medical therapy for heart failure. While cardiac conduction defects and need for ventricular pacing are common in congential heart disease, CRT indications, techniques and long term outcomes have not been well establaished. This is a review of the techniques nad short term outcomes of CRT for the following complex congenital heart disease conditions: single ventricle physiology, systemic right ventricle, and the subpulmonic right ventricle.

Long-Term outcomes in adult patients with congenital heart disease considered for transplantation: A single center study

BACKGROUND

Adult congenital heart disease (ACHD) patients pose unique challenges in identifying the time for transplantation and factors influencing outcomes.

OBJECTIVE

To identify hemodynamic, functional, and laboratory parameters that correlate with 1- and 10-year outcomes in ACHD patients considered for transplantation.

METHODS

A retrospective chart review of long-term outcomes in adult patients with congenital heart disease (CHD) evaluated for heart or heart + additional organ transplant between 2004 and 2014 at our center was performed. A machine learning decision tree model was used to evaluate multiple clinical parameters correlating with 1- and 10-year survival.

RESULTS

We identified 58 patients meeting criteria. D-transposition of the great arteries (D-TGA) with atrial switch operation (20.7%), tetralogy of Fallot/pulmonary atresia (15.5%), and tricuspid atresia (13.8%) were the most common diagnosis for transplant. Single ventricle patients were most likely to be listed for transplantation (39.8% of evaluated patients). Among a comprehensive list of clinical factors, invasive hemodynamic parameters (pulmonary capillary wedge pressure (PCWP), systemic vascular pressure (SVP), and end diastolic pressures (EDP) most correlated with 1- and 10-year outcomes. Transplanted patients with SVP < 14 and non- transplanted patients with PCWP < 15 had 100% survival 1-year post-transplantation.

CONCLUSION

For the first time, our study identifies that hemodynamic parameters most strongly correlate with 1- and 10-year outcomes in ACHD patients considered for transplantation, using a data-driven machine learning model.

Multimodality Imaging Assessment of Tetralogy of Fallot: From Diagnosis to Long-Term Follow-Up

Tetralogy of Fallot (TOF) is the most common complex congenital heart disease with long-term survivors, demanding serial monitoring of the possible complications that can be encountered from the diagnosis to long-term follow-up. Cardiovascular imaging is key in the diagnosis and serial assessment of TOF patients, guiding patients' management and providing prognostic information. Thorough knowledge of the pathophysiology and expected sequalae in TOF, as well as the advantages and limitations of different non-invasive imaging modalities that can be used for diagnosis and follow-up, is the key to ensuring optimal management of patients with TOF. The aim of this manuscript is to provide a comprehensive overview of the role of each modality and common protocols used in clinical practice in the assessment of TOF patients.

Overcoming Underpowering in the Outcome Analysis of Repaired-Tetralogy of Fallot: A Multicenter Database from the CMR/CT Working Group of the Italian Pediatric Cardiology Society (SICPed)

Background: Managing repaired tetralogy of Fallot (TOF) patients is still challenging despite the fact that published studies identified prognostic clinical or imaging data with rather good negative predictive accuracy but weak positive predictive accuracy. Heterogeneity of the initial anatomy, the surgical approach, and the complexity of the mechanism leading to dilation and ventricular dysfunction explain the challenge of predicting the adverse event in this population. Therefore, risk stratification and management of this population remain poorly standardized. Design: The CMR/CT WG of the Italian Pediatric Cardiology Society set up a multicenter observational clinical database of repaired TOF evaluations. This registry will enroll patients retrospectively and prospectively assessed by CMR for clinical indication in many congenital heart diseases (CHD) Italian centers. Data collection in a dedicated platform will include surgical history, clinical data, imaging data, and adverse cardiac events at 6 years of follow-up. Summary: The multicenter repaired TOF clinical database will collect data on patients evaluated by CMR in many CHD centers in Italy. The registry has been set up to allow future research studies in this population to improve clinical/surgical management and risk stratification of this population.

Novel Therapeutic Strategies in Heart Failure in Adult Congenital Heart Disease: of Medicines and Devices

PURPOSE OF REVIEW

This paper reviews the latest literature on the growing field of heart failure in the adult congenital heart disease population.

RECENT FINDINGS

After highlighting the increasing prevalence and a few of the unique potential causes, including the concept of early senescence, this review begins with novel medical management strategies such as the angiotensin II receptor blocker and neprilysin inhibitors and sodium glucose cotransporter-2 inhibitors. Then, it addresses the latest applications of percutaneous techniques like implantable hemodynamic monitoring, transcatheter pulmonary and aortic valve replacement, and mitral clips. Cardiac resynchronization therapy and novel lymphatic system imaging and intervention are then described. Finally, the use of mechanical support devices, temporary and durable, is discussed as well as heart and combined heart and liver transplantation. There have been recent exciting advances in the strategies used to manage adult congenital heart disease patients with heart failure. As this population continues to grow, it is likely we will see further rapid evolution in this field.

Decreased cardiac reserve in asymptomatic patients after arterial switch operation for transposition of the great arteries

BACKGROUND

Exercise capacity is impaired in patients after arterial switch operation (ASO) for complete transposition of the great arteries. Maximal oxygen consumption is related with outcome.

OBJECTIVES

This study assessed ventricular function by advanced echocardiography and cardiac magnetic resonance (CMR) imaging at rest and during exercise, to determine exercise capacity in ASO patients, and to correlate exercise capacity with ventricular function as potential early marker of subclinical impairment.

METHODS

Forty-four patients (71% male, mean age 25 ± 4 years - range 18-40 years) were included during routine clinical follow-up. Assessment involved physical examination, 12‑lead ECG, echocardiography, and cardiopulmonary exercise test (CPET) (day 1). On day 2 CMR imaging at rest and during exercise was performed. Blood was sampled for biomarkers.

RESULTS

All patients reported New York Heart Association class I, the overall cohort had an impaired exercise capacity (80 ± 14% of predicted peak oxygen consumption). Fragmented QRS was present in 27%. Exercise CMR showed that 20% of patients had abnormal contractile reserve (CR) of the left ventricle (LV) and 25% had reduced CR of the right ventricle (RV). CR LV and CR RV were significantly associated with impaired exercise capacity. Pathological patterns on myocardial delayed enhancement and hinge point fibrosis were detected. Biomarkers were normal.

CONCLUSION

This study found that in some asymptomatic ASO patients electrical, LV and RV changes at rest, and signs of fibrosis are present. Maximal exercise capacity is impaired and seems to be linearly related to the CR of the LV and the RV. Therefore, exercise CMR might play a role in detecting subclinical deterioration of ASO patients.

Repair of Aortic Regurgitation in Young Adults: Sooner Rather Than Later

Background Establishing surgical criteria for aortic valve replacement (AVR) in severe aortic regurgitation in young adults is challenging due to the lack of evidence-based recommendations. We studied indications for AVR in young adults with severe aortic regurgitation and their outcomes, as well as the relationship between presurgical echocardiographic parameters and postoperative left ventricular (LV) size, function, clinical events, and valve-related complications. Methods and Results Data were collected retrospectively on 172 consecutive adult patients who underwent AVR or repair for severe aortic regurgitation between 2005 and 2019 in a tertiary cardiac center (age at surgery 29 [22-41] years, 81% male). One-third underwent surgery before meeting guideline indications. Postsurgery, 65% achieved LV size and function normalization. LV ejection fraction showed no significant change from baseline. A higher presurgical LV end-systolic diameter correlated with a lack of LV normalization (odds ratio per 1-cm increase 2.81, P<0.01). The baseline LV end-systolic diameter cut-off for predicting lack of LV normalization was 43 mm. Pre- and postoperative LV dimensions and postoperative LV ejection fraction predicted clinical events during follow-up. Prosthetic valve-related complications occurred in 20.3% during an average 5.6-year follow-up. Freedom from aortic reintervention was 98%, 96.5%, and 85.4% at 1, 5, and 10 years, respectively. Conclusions Young adult patients with increased baseline LV end-systolic diameter or prior cardiac surgery are less likely to achieve LV normalization after AVR. Clinicians should carefully balance the long-term benefits of AVR against procedural risks and future interventions, especially in younger patients. Evidence-based criteria for AVR in severe aortic regurgitation in young adults are crucial to improve outcomes.

Cardiopulmonary functional capacity in Taiwanese children with ventricular septal defects

BACKGROUND

Children with ventricular septal defects (VSDs) are considered to have no difference in cardiopulmonary functional capacity with healthy children of the same age; however, studies have shown contradictory findings. The aim of this study was to assess whether Taiwanese children with VSDs exhibited cardiopulmonary deficits.

METHODS

This is a retrospective cohort study with the data collected from January 2010 to December 2021. All patients and controls (age-, sex-, and body mass index -matched) underwent cardiopulmonary exercise testing (CPET) and pulmonary function test.

RESULTS

In total, 157 VSD patients (80 patients with surgically closed VSDs, 77 patients with unrepaired VSDs) and 157 healthy controls were recruited. Pulmonary function test showed significant among-group differences in maximal voluntary ventilation (MVV) (p = 0.015). The surgically closed group had lower MVV compared to the control group. Regarding CPET, we found VSD patients had lower peak oxygen uptake than the controls (surgically closed group: 30.84 ± 6.27 ml/kg/min; unrepaired group: 32.00 ± 5.95 ml/kg/min; control group: 36.76 ± 6.50 ml/kg/min, p < 0.001). There was also significant among-group differences in aerobic capacity (surgically closed group: 21.20 ± 4.39 ml/kg/min; unrepaired group: 21.68 ± 4.47 ml/kg/min; control group: 26.25 ± 4.33 ml/kg/min, p < 0.001). In addition, the surgically closed group had lower heart rate average at anaerobic threshold than the control group (surgically closed group: 138.11 ± 16.42 bpm; control group: 145.78 ± 15.53 bpm, p = 0.002).

CONCLUSION

Taiwanese children with VSD, whether surgically closed or not, have poorer cardiopulmonary performance than age-matched healthy children, and the results of the surgically closed group were even worse.

Short-term results of serial cardiopulmonary exercise testing in adults with repaired coarctation of the aorta

BACKGROUND

Data on the evolution of exercise capacity in adults with repaired coarctation of the aorta (CoA) are scarce. We aimed to investigate the evolution and change of measures of exercise capacity obtained by cardiopulmonary exercise testing (CPET) in adults with repaired CoA.

METHODS

Patients 16 years of age and older with CoA, who performed at least two maximal CPETs in our institution, were included in the study. The first and last available tests were used for comparative statistical analysis of common exercise variables.

RESULTS

Sixty patients (43 men) performed serial maximal CPET. Mean age at first assessment was 30 ± 10 years (range 17-68). Mean time between first and last assessment was 3.5 years (range 1-7). Mean peak VO2 was 85.6 ± 20.4% of the predicted value at the initial test, and 87.0 ± 20.5% at the final test (p = 0.294). There were no significant differences in the mean values of oxygen pulse, VO2 at anaerobic threshold, systolic and diastolic blood pressures and peak heart rate between the two assessments. There was a slightly higher VE/VCO2 slope at the final test (p = 0.047). Higher age and Borg scale were found to be related with a decline in percent-predicted peak VO2 from initial to final assessment.

CONCLUSION

In adults with repaired CoA, we found no significant change in peak VO2 during a mean follow-up of 3.5 years, yet a small increase in VE/VCO2 slope was observed. Higher age was predictive for a decline in percent-predicted peak VO2, starting in the third decade of life.

The Current Role of Cardiopulmonary Exercise Test in the Diagnosis and Management of Pulmonary Hypertension

Pulmonary arterial hypertension (PAH) is a progressive disease with a poor prognosis if left untreated. Despite remarkable achievements in understanding disease pathophysiology, specific treatments, and therapeutic strategies, we are still far from a definitive cure for the disease, and numerous evidences have underlined the importance of early diagnosis and treatment to improve the prognosis. Cardiopulmonary exercise testing (CPET) is the gold standard for assessing functional capacity and evaluating the pathophysiological mechanisms underlying exercise limitation. As effort dyspnea is the earliest and one of the main clinical manifestations of PAH, CPET has been shown to provide valid support in early detection, differential diagnosis, and prognostic stratification of PAH patients, being a useful tool in both the first approach to patients and follow-up. The purpose of this review is to present the current applications of CPET in pulmonary hypertension and to propose possible future utilization to be further investigated.

The cardiorespiratory optimal point as a discriminator of lesion severity in adults with congenital heart disease

BACKGROUND

Peak oxygen consumption (VO2peak), which depends on maximal exertion and is reduced in adults with congenital heart disease (ACHD), is associated with lesion severity. The lowest ventilatory equivalent for oxygen (the minimum value of VE/VO2) reflects the cardiorespiratory optimal point (COP) as best possible respiration-circulatory interaction and may discriminate between lesion types without the need for maximal exertion. However, data on COP in ACHD is scarce.

METHODS

We retrospectively analyzed stable ACHD with moderate (N.=13) and severe lesions (N.=17) reporting to our outpatient clinic undergoing cardiopulmonary exercise testing. The primary outcome of the study was the difference of COP between moderate and severe lesions. Secondary outcomes were between group differences of the submaximal variable exercise oxygen uptake efficiency slope (OUES) and peak O2 pulse (O2pulsemax) as a surrogate for peripheral oxygen extraction and stroke volume increase during exercise.

RESULTS

The group of severe lesions displayed higher COP (29.5±7.0 vs. 25.2±6.2, P=0.028) as well as lower O2pulsemax (13.3±8.4 vs. 14.9±3.4 mL/beat/kg 102, P=0.038). VO2peak (17.4±6.5 vs. 20.8±8.5 mL/kg/min, P=0.286) and OUES (1.5±0.7 vs. 1.8±0.9, P=0.613) showed a trend towards lower values in severe lesions. COP was a better between group discriminator than O2pulsemax (area under the curve 73.8% vs. 72.4%).

CONCLUSIONS

As a submaximal variable, COP discriminated between moderate and severe lesions and may prove beneficial in a highly vulnerable population that is often unable to undergo exertional testing.

Facility-Based and Virtual Cardiac Rehabilitation in Young Patients with Heart Disease During the COVID-19 Era

Cardiac rehabilitation (CR) is an important tool for improving fitness and quality of life in those with heart disease (HD). Few pediatric centers use CR to care for these patients, and virtual CR is rarely used. In addition, it is unclear how the COVID-19 era has changed CR outcomes. This study assessed fitness improvements in young HD patients participating in both facility-based and virtual CR during the COVID-19 pandemic. This retrospective single-center cohort study included new patients who completed CR from March 2020 through July 2022. CR outcomes included physical, performance, and psychosocial measures. Comparison between serial testing was performed with a paired t test with P < 0.05 was considered significant. Data are reported as mean ± standard deviation. There were 47 patients (19 ± 7.3 years old; 49% male) who completed CR. Improvements were seen in peak oxygen consumption (VO₂, 62.3 ± 16.1 v 71 ± 18.2% of predicted, p = 0.0007), 6-min walk (6 MW) distance (401 ± 163.8 v 480.7 ± 119.2 m, p =  < 0.0001), sit to stand (16.2 ± 4.9 v 22.1 ± 6.6 repetitions; p =  < 0.0001), Patient Health Questionnaire-9 (PHQ-9) (5.9 ± 4.3 v 4.4 ± 4.2; p = 0.002), and Physical Component Score (39.9 ± 10.1 v 44.9 ± 8.8; p = 0.002). Facility-based CR enrollees were less likely to complete CR than virtual patients (60%, 33/55 v 80%, 12/15; p = 0.005). Increases in peak VO₂ (60 ± 15.3 v 70.2 ± 17.8% of predicted; p = 0.002) were seen among those that completed facility-based CR; this was not observed in the virtual group. Both groups demonstrated improvement in 6 MW distance, sit-to-stand repetitions, and sit-and-reach distance. Completion of a CR program resulted in fitness improvements during the COVID-19 era regardless of location, although peak VO₂ improved more for the in-person group.

ehealth technology in cardiac exercise therapeutics for pediatric patients with congenital and acquired heart conditions: a summary of evidence and future directions

Many children and adolescents with congenital and acquired heart disease (CHD) are physically inactive and participate in an insufficient amount of moderate-to-vigorous intensity exercise. Although physical activity (PA) and exercise interventions are effective at improving short- and long-term physiological and psychosocial outcomes in youth with CHD, several barriers including resource limitations, financial costs, and knowledge inhibit widespread implementation and dissemination of these beneficial programs. New and developing eHealth, mHealth, and remote monitoring technologies offer a potentially transformative and cost-effective solution to increase access to PA and exercise programs for youth with CHD, yet little has been written on this topic. In this review, a cardiac exercise therapeutics (CET) model is presented as a systematic approach to PA and exercise, with assessment and testing guiding three sequential PA and exercise intervention approaches of progressive intensity and resource requirements: (1) PA and exercise promotion within a clinical setting; (2) unsupervised exercise prescription; and (3) medically supervised fitness training intervention (i.e., cardiac rehabilitation). Using the CET model, the goal of this review is to summarize the current evidence describing the application of novel technologies within CET in populations of children and adolescents with CHD and introduce potential future applications of these technologies with an emphasis on improving equity and access to patients in low-resource settings and underserved communities.

Death, reoperation, and late cardiopulmonary function after truncus repair

Objective

To identify the late surgical outcomes of truncus arteriosus.

Methods

Fifty consecutive patients with truncus arteriosus who underwent surgery between 1978 and 2020 at our institute were enrolled in this retrospective, single institutional cohort study. The primary outcome was death and reoperation. The secondary outcome was late clinical status, including exercise capacity. The peak oxygen uptake was measured by a ramp-like progressive exercise test on a treadmill.

Results

Nine patients underwent palliative surgery, which resulted in 2 deaths. Forty-eight patients went on to truncus arteriosus repair, including 17 neonates (35.4%). The median age and body weight at repair were 92.5 days (interquartile range, 10-272 days) and 3.85 kg (interquartile range, 2.9-6.5 kg), respectively. The survival rate at 30 years was 68.5%. Significant truncal valve regurgitation (P = .030) was a risk factor for survival. Survival rates were similar between in the early 25 and late 25 patients (P = .452). The freedom from death or reoperation rate at 15 years was 35.8%. Significant truncal valve regurgitation was a risk factor (P = .001). The mean follow-up period in hospital survivors was 15.4 ± 12 years (maximum, 43 years). The peak oxygen uptake, which was performed in 12 long-term survivors at a median duration from repair of 19.7 years (interquartile range, 16.8-30.9 years), was 70.2% of predicted normal (interquartile range, 64.5%-80.4%).

Conclusions

Truncal valve regurgitation was a risk factor for both survival and reoperation, thus improvement of truncal valve surgery is essential for better life prognosis and quality of life. Slightly reduced exercise tolerance was common in long-term survivors.

Minimal-Access Atrial Septal Defect (ASD) Closure

Progress towards the development and adoption of minimally invasive techniques in cardiac surgery has been slower than that seen in other surgical specialties. Congenital heart disease (CHD) patients represent an important population within cardiac disease, of which atrial septal defect (ASD) is one of the most common diagnoses. Management of ASD encompasses a range of minimal-access and minimally invasive approaches, including transcatheter device closure, mini-sternotomy, thoracotomy, video-assisted, endoscopic, and robotic approaches. In this article, we will discuss the pathophysiology of ASD, along with diagnosis, management, and indications for intervention. We will review the current evidence supporting minimally invasive and minimal-access surgical ASD closure in the adult and paediatric patient, highlighting peri-operative considerations and areas for further research.

Successful complex percutaneous intervention in patient with Fontan circulation and severe heart failure: A case report

We report the case of a successful complex percutaneous intervention in a patient with Fontan circulation and severe heart failure. The patient presented with cyanosis; Fontan conduit stenosis was detected, and the fenestration was patent. The complex interventional procedure allowed for a long-term stabilization of the patient's condition.

Elevated oxidative stress in patients with congenital heart disease and the effect of cyanosis: a meta-analysis

Oxidative stress is an important pathophysiological mechanism in the development of numerous cardiovascular disorders. To improve therapy and preventive strategies, clinicians need a better understanding of the underlying pathophysiological mechanisms of congenital heart diseases (CHD). The objective of this meta-analysis was to determine whether oxidative stress is elevated in patients with CHD compared to healthy controls, and to evaluate whether a difference in oxidative stress parameters can be observed between patients with cyanotic (cCHD) and acyanotic CHD (aCHD). Therefore, 21 studies investigating oxidative stress in peripheral blood of both children and adults with CHD were reviewed. Different methods to assess the oxidant status were compared and divided into three categories: pro-oxidative or anti-oxidative stress markers and the ratio of pro-to-anti oxidative stress markers. This meta-analysis showed elevated oxidative stress levels in patients with CHD, and more specifically in patients with cCHD. Moreover, this indicates that there could be potential in oxidative stress measurements as a new biomarker of disease severity. Further research will be needed to clarify the exact role of oxidative stress and its contributors in CHD in order to get a better and more in-depth understanding of the underlying pathophysiology of CHD, especially the higher susceptibility of the right ventricle (RV) to progress to heart failure (HF). This could facilitate the development of antioxidant treatments and RV-specific HF therapies, which are necessary to improve survival in these patients and could be of particular importance in cCHD.

Surrogates of Muscle Mass on Cardiac MRI Correlate with Exercise Capacity in Patients with Fontan Circulation

BACKGROUND

Sarcopenia is an increasingly recognized marker of frailty in cardiac patients. Patients with a history of congenital heart disease and Fontan procedure have a higher risk of developing progressive muscle wasting. Our objective was to determine if we could use routine cardiac MRI (CMR) for the surveillance of muscle wasting.

METHODS

A retrospective study of all Fontan patients (n = 75) was conducted at our institution, with CMR performed from 2010 to 2022 and exercise stress testing performed within 12 months (4.3 ± 4.2 months). The skeletal muscle area (SMA) for the posterior paraspinal and anterior thoracic muscles were traced and indexed for body surface area (BSA). Patients were stratified by percentile into the upper and lower quartiles, and the two groups were compared. Multivariable regression was performed to control for sex and age.

RESULTS

There was a significant positive association of both anterior (r = 0.34, p = 0.039) and paraspinal (r = 0.43, p = 0.007) SMA to peak VO2. Similarly, paraspinal but not anterior SMA was negatively associated with the VE/VCO2 (r = -0.45, p = 0.006). The upper quartile group had significantly more males (18/19 vs. 8/20; p = 0.0003) and demonstrated a significantly higher peak VO2 (32.2 ± 8.5 vs. 23.8 ± 4.7, p = 0.009), a higher peak RER (1.2 ± 0.1 vs. 1.1 ± 0.04, p = 0.007), and a significantly lower VE/VCO2 (32.9 ± 3.6 vs. 40.2 ± 6.2, p = 0.006) compared to the lowest quartile. The association of SMA to VO2 peak and VE/VCO2 was redemonstrated after controlling for sex and age.

CONCLUSION

Thoracic skeletal muscle area may be an effective surrogate of muscle mass and is correlated to several measures of cardiorespiratory fitness post-Fontan. CMR would be an effective tool for the surveillance of sarcopenia in post-Fontan patients given its accessibility and routine use in these patients.

Characteristics of exercise intolerance in different subgroups of pulmonary arterial hypertension associated with congenital heart disease

BACKGROUND

Exercise intolerance is a major manifestation of pulmonary arterial hypertension associated with congenital heart disease (PAH-CHD). We aimed to investigate the characteristics of exercise intolerance in different subgroups of PAH-CHD.

METHODS

We retrospectively enrolled 171 adult patients with PAH-CHD and 30 age and sex-matched healthy subjects and performed cardiopulmonary exercise testing. Gas exchange parameters, including peak oxygen uptake (peak V̇o₂), anaerobic threshold, and the slope of ventilatory equivalent for carbon dioxide (V̇e/V̇co₂ slope), were recorded.

RESULTS

The median age of patients at enrollment was 27.8 years, and 131 (76.6%) were female. Peak V̇o₂ was reduced in patients compared to healthy controls (median, 14.8 ml/kg/min versus 26.9 ml/kg/min, p < 0.001). Of all 171 patients, 60 (35.1%) had Eisenmenger syndrome, 35 (20.5%) had PAH associated with systemic-to-pulmonary shunts (PAH-SP), 39 (22.8%) had PAH with small defects (PAH-SD), and 37 (21.6%) had PAH after cardiac defect correction (PAH-CD). Patients with Eisenmenger syndrome had the lowest peak V̇o₂ (p = 0.003) and the highest V̇e/V̇co₂ slope (p = 0.012), compared with other patients, representing the worst exercise capacity and ventilatory efficiency. Patients with PAH-SP had the best exercise capacity among the four groups, indicated by the highest peak V̇o₂ (p = 0.003) compared with other patients. Peak V̇o₂ was negatively correlated with pulmonary vascular resistance (r = -0.411, p < 0.001).

CONCLUSIONS

Exercise capacity was severely reduced in patients with PAH-CHD. Among the four subgroups, patients with Eisenmenger syndrome had the worst exercise capacity and ventilatory efficiency.

Overshoot of the Respiratory Exchange Ratio during Recovery from Maximal Exercise Testing in Young Patients with Congenital Heart Disease

Introduction: The overshoot of the respiratory exchange ratio (RER) after exercise is reduced in patients with heart failure. Aim: The present study aimed to investigate the presence of this phenomenon in young patients with congenital heart disease (CHD), who generally present reduced cardiorespiratory fitness. Methods: In this retrospective study, patients with CHD underwent a maximal cardiopulmonary exercise testing (CPET) assessing the RER recovery parameters: the RER at peak exercise, the maximum RER value reached during recovery, the magnitude of the RER overshoot and the linear slope of the RER increase after the end of the exercise. Results: In total, 117 patients were included in this study. Of these, there were 24 healthy age-matched control subjects and 93 young patients with CHD (transposition of great arteries, Fontan procedure, aortic coarctation and tetralogy of Fallot). All patients presented a RER overshoot during recovery. Patients with CHD showed reduced aerobic capacity and cardiorespiratory efficiency during exercise, as well as a lower RER overshoot when compared to controls. RER magnitude was higher in the controls and patients with aortic coarctation when compared to those with transposition of great arteries, previous Fontan procedure, and tetralogy of Fallot. The RER magnitude was found to be correlated with the most relevant cardiorespiratory fitness and efficiency indices. Conclusions: The present study proposes new recovery indices for functional evaluation in patients with CHD. Thus, the RER recovery overshoots analysis should be part of routine CPET evaluation to further improve prognostic risk stratifications in patients with CHD.

Ambivalence is associated with decreased physical activity and cardiorespiratory fitness among adolescents with critical congenital heart disease

BACKGROUND

Adolescents with congenital heart disease (CHD) are insufficiently physically active. Given that increasing physical activity may reduce their cardiovascular risk, it is important to identify correlates of this behavior. Perceived benefits of and barriers to physical activity are associated with physical activity engagement. Existing research has only considered these constructs separately. This population may be ambivalent toward physical activity (i.e., perceive both strong benefits and barriers). The association of ambivalence and physical activity related outcomes is unknown among this at-risk population.

OBJECTIVE

Determine the association of ambivalence and sedentary behavior, moderate-to-vigorous physical activity (MVPA), and cardiorespiratory fitness (VO2Peak) among adolescents with CHD.

METHODS

The present study is an analysis of data from an eligibility assessment for a randomized clinical trial of an intervention to promote MVPA among adolescents aged 15 to 18 years with moderate or complex CHD. Participants (N = 84) completed a survey assessing perceived benefits and barriers from which ambivalence toward physical activity was calculated, an exercise stress test to measure VO2Peak, and wore an accelerometer for one week to determine their engagement in sedentary behavior and MVPA. Linear regression analyses determined associations between ambivalence and physical activity related outcomes. RESULTS: Greater ambivalence toward physical activity was associated with increased sedentary behavior, decreased MVPA, and reduced VO2Peak, adjusting for demographic and clinical covariates.

CONCLUSIONS

Ambivalence is associated with objectively measured physical activity (sedentary behavior, MVPA) and a biomarker of cardiovascular health (VO2Peak). Screening for ambivalence may help clinicians identify those most likely to benefit from physical activity-related education.

Exercise Capacity in Patients with Pulmonary Atresia with Intact Ventricular Septum: Does the Type of Surgical Repair Matter?

Two standard surgical palliative options for neonates born with pulmonary atresia and intact ventricular septum (PA/IVS) include uni-or biventricular repair. Whenever feasible, the biventricular repair is considered to have better exercise capacity (XC) and outcomes. However, there is a paucity of data comparing objective XC between these two surgical techniques. Our aim was to compare XC, including longitudinal changes in patients with PA/IVS following uni-biventricular repair. We performed a single-center retrospective study of survivors with repaired PA/IVS who underwent comprehensive treadmill cardiopulmonary exercise testing. Initial and latest exercise parameters were compared for longitudinal analysis. Demographic and exercise parameters were collated. Peak oxygen uptake (VO₂ in ml/kg/min), an indicator of maximal aerobic capacity, peak heart rate, and other measures of spirometry performed at the same time were collected. Recorded parameters included, (a) Percentage of predicted VO₂ (% VO2) normalized for age, weight, height, and gender, (b) % oxygen (O₂) pulse, (c) anaerobic threshold (AT), (d) Chronotropic index (CI), (e) % Breathing reserve, (f) Forced vital capacity (FVC), (g) % Forced Expiratory volume in 1 s (FEV1), (h) Maximum voluntary ventilation (MVV), and (i) VE/VCO₂. Appropriate statistical tests were performed, and a p value < 0.05 was considered significant. A total of 35 patients (43% male, 57% univentricular repair) were included, with a mean (SD) age of 20.1(7.5) years. Patients with univentricular palliation demonstrated significantly impaired peak heart rate, chronotropic index (0.50 ± 0.2 vs. 0.90 ± 0.1, p = 0.02), VE/VCO₂ (35.4 ± 5.0 vs. 30.2 ± 2.8, p = 0.001), and %FVC (78.3 ± 8.3 vs. 88.6 ± 15.1, p = 0.02). There was a trend towards reduction in % VO₂ in the Fontan patients though it was statistically similar between the groups (68.4 ± 21.4 vs. 81.2 ± 18.9, p = 0.07). Longitudinal data were available for 11 patients in each group, and there was no longitudinal decline in their exercise parameters over similar intermediate follow-up duration [6.8 (UV) vs. 5.3 (BV) years]. We conclude that young survivors with PA/IVS with prior univentricular palliation demonstrated an objective impairment in their chronotropic parameters compared with the biventricular repair. However, this did not translate into a significant difference in their exercise capacity. There was no longitudinal decline in exercise capacity or other parameters over intermediate follow-up.

Which risk score best predicts cardiovascular outcome in pregnant women with congenital heart disease?

BACKGROUND

Management of pregnancy and risk stratification in women with congenital heart diseases (CHD) are challenging, especially due to physiological haemodynamic modifications that inevitably occur during pregnancy.

AIMS

To compare the accuracy of the existing pregnancy cardiovascular risk scores in prediction of maternal complications during pregnancy in CHD patients.

METHOD AND RESULTS

From 2007 to 2018, all pregnant women with a CHD who delivered birth after 20 weeks of gestation were identified. The discriminating power and the accuracy of the five existing pregnancy cardiovascular risk scores [CARPREG, CARPREG II, HARRIS, ZAHARA risk scores, and modified WHO (mWHO)] were evaluated.Out of 104 pregnancies in 65 CHD patients, 29% experienced cardiovascular complications during pregnancy or post-partum. For the five scores, the observed rate of cardiovascular events was higher than the expected risk. The values of area under the ROC curve were 0.75 (0.62-0.88) for mWHO, 0.65 (0.53-0.77) for CARPREG II, 0.60 (0.40-0.80) for HARRIS, 0.59 (0.47-0.72) for ZAHARA, and 0.58 (0.43-0.73) for CARPREG.

CONCLUSION

The modified WHO classification appeared to better predict cardiovascular outcome in pregnant women with CHD than the four other existing risk scores.Clinical Trial Registration: Clinicaltrials.gov: NCT04221048.

Congenital heart disease-associated pulmonary dysplasia and its underlying mechanisms

Clinical observation indicates that exercise capacity, an important determinant of survival in patients with congenital heart disease (CHD), is most decreased in children with reduced pulmonary blood flow (RPF). However, the underlying mechanism remains unclear. Here, we obtained human RPF lung samples from children with tetralogy of Fallot as well as piglet and rat RPF lung samples from animals with pulmonary artery banding surgery. We observed impaired alveolarization and vascularization, the main characteristics of pulmonary dysplasia, in the lungs of RPF infants, piglets, and rats. RPF caused smaller lungs, cyanosis, and body weight loss in neonatal rats and reduced the number of alveolar type 2 cells. RNA sequencing demonstrated that RPF induced the downregulation of metabolism and migration, a key biological process of late alveolar development, and the upregulation of immune response, which was confirmed by flow cytometry and cytokine detection. In addition, the immunosuppressant cyclosporine A rescued pulmonary dysplasia and increased the expression of the Wnt signaling pathway, which is the driver of postnatal lung development. We concluded that RPF results in pulmonary dysplasia, which may account for the reduced exercise capacity of patients with CHD with RPF. The underlying mechanism is associated with immune response activation, and immunosuppressants have a therapeutic effect in CHD-associated pulmonary dysplasia.

Long-Term Results of Serial Exercise Testing and Echocardiography Examinations in Patients with Pulmonary Stenosis

Pulmonary stenosis (PS) affects cardiopulmonary function and exercise performance. Cardiopulmonary exercise testing (CPET) together with transthoracic echocardiography (TTE) can measure exercise performance, PS progression, and treatment effects. We assessed exercise capacity in PS patients using these methods. We enrolled 28 PS patients aged 6-35 years who received surgery, balloon pulmonary valvuloplasty, and follow-up care. The control population was selected by a 1:1 matching on age, sex, and body mass index. Baseline and follow-up peak pulmonary artery pulse wave velocity (PAV) were compared using TTE. Initial CPET revealed no significant differences in anaerobic metabolic equivalent (MET), peak oxygen consumption (VO₂), and heart rate recovery between the two groups, nor were significant differences in pulmonary function identified. Within the PS group, there were no significant differences in MET, peak VO₂, and heart rate recovery between the baseline and final CPET. Similarly, no significant differences were observed between the baseline and final PAV. The exercise capacity of patients with properly managed PS was comparable to that of healthy individuals. However, during the follow-up, declining trends in pulmonary function, aerobic metabolism, and peak exercise load capacity were observed among adolescents with PS. This study provides long-term data suggesting that PS patients should be encouraged to perform physical activity. Regular reevaluation should also be encouraged to limit performance deterioration.