Sjoerd S.M. Bossers

Computational fluid dynamics in Fontan patients to evaluate power loss during simulated exercise

Objective Exercise intolerance is common in total cavopulmonary connection (TCPC) patients. It has been suggested that power loss (Ploss) inside the TCPC plays a role in reduced exercise performance. Our objective is to establish the role of Ploss inside the TCPC during increased flow, simulating exercise in a patient-specific way. Methods Cardiac MRI (CMR) was used to obtain flow rates from the caval veins during rest and increased flow, simulating exercise with dobutamine. A 3D reconstruction of the TCPC was created using CMR data. Computational fluid dynamics (CFD) simulations were performed to calculate Ploss inside the TCPC structure for rest and stress conditions. To reflect the flow distribution during exercise, a condition where inferior caval vein (IVC) flow was increased twofold compared with rest was added. 29 TCPC patients (15 intra-atrial lateral tunnel (ILT) and 14 extracardiac conduit (ECC)) were included. Results Mean Ploss at rest was 1.36±0.94 (ILT) and 3.20±1.26 (ECC) mW/m2 (p<0.001), 2.84±1.95 (ILT) and 8.41±3.77 (ECC) mW/m2 (p<0.001) during dobutamine and 5.21±3.50 (ILT) and 15.28±8.30 (ECC) mW/m2 (p=0.001) with twofold IVC flow. The correlation between cardiac index and Ploss was exponential (ILT: R2=0.811, p<0.001; ECC: R2=0.690, p<0.001). Conclusions Ploss inside the TCPC structure is limited but increases with simulated exercise. This relates to the anatomy of TCPC and the surgical technique used. In all flow conditions, ILT patients have lower Ploss than ECC patients. We did not find a relationship between Ploss and exercise capacity.

Exercise capacity in children after total cavopulmonary connection: Lateral tunnel versus extracardiac conduit technique

OBJECTIVES In patients with univentricular heart disease, the total cavopulmonary connection (TCPC) is the preferred treatment. TCPC can be performed using the intra-atrial lateral tunnel (ILT) or extracardiac conduit (ECC) technique. The purpose of the present study was to evaluate exercise capacity in contemporary TCPC patients and compare the results between the 2 techniques. METHODS A total of 101 TCPC patients (ILT, n=42; ECC, n=59; age, 12.2±2.6 years; age at TCPC completion, 3.2±1.1 years) underwent cardiopulmonary exercise testing. The patients were recruited prospectively from 5 tertiary referral centers. RESULTS For the entire group, the mean peak oxygen uptake was 74%±14%, peak heart rate was 90%±8%, peak workload was 62%±13%, and slope of ventilation versus carbon dioxide elimination (VE/VCO2 slope) was 127%±30% of the predicted value. For the ILT and ECC groups, patient age, age at TCPC completion, body surface area, peak workload, and peak heart rate were comparable. The percentage of predicted peak oxygen uptake was lower in the ILT group (70%±12% vs 77%±15%; P=.040), and the percentage of predicted VE/VCO2 slope was greater in the ILT group (123%±36% vs 108%±14%; P=.015). In a subgroup analysis that excluded ILT patients with baffle leak, these differences were not statistically significant. CONCLUSIONS Common exercise parameters were impaired in contemporary Fontan patients. Chronotropic incompetence was uncommon. The peak oxygen uptake and VE/VCO2 slope were less favorable in ILT patients, likely related to baffle leaks in some ILT patients. These results have shown that a reduced exercise capacity in Fontan patients remains an important issue in contemporary cohorts. The ECC had a more favorable exercise outcome at medium-term follow-up.

Ventricular function and cardiac reserve in contemporary Fontan patients

BACKGROUND/OBJECTIVE Total cavopulmonary connection (TCPC) has been the preferred treatment for patients with univentricular hearts. Current TCPC-techniques are the intra-atrial lateral tunnel (ILT) and the extracardiac conduit (ECC). We aimed to determine ventricular function during rest and stress, and to compare results for both techniques and for left (LV) versus right ventricular (RV) dominance. METHODS 99 patients, aged 12.5 ± 4.0 years underwent echocardiography and magnetic resonance imaging (MRI), and 69 patients underwent stress MRI. RESULTS Echocardiography showed impaired systolic and diastolic function. MRI parameters were comparable between ILT and ECC at rest. During dobutamine there was a decrease in end-diastolic volume (EDVi) (91 ± 21 vs. 80 ± 20 ml/m(2) p<0.001). Ejection fraction (EF) and cardiac index (CI) during dobutamine were lower for ILT patients (59 ± 11 (ILT) vs. 64 ± 7% (ECC), p=0.027 and 4.2 ± 1.0 (ILT) vs. 4.9 ± 1.0L/min/m(2) (ECC), p=0.006), whereas other parameters were comparable. TEI-index was higher in ILT-patients (0.72 ± 0.27 (ILT) vs. 0.56 ± 0.22 (ECC), p=0.002). Diastolic function was frequently impaired in patients with a dominant RV (67% (RV) vs. 39% (LV), p=0.011). Patients with dominant LVs had smaller end-systolic volume (ESVi) (40 ± 13 (LV) vs. 47 ± 16 (RV) ml/m(2), p=0.030) and higher EF (55 ± 8 (LV) vs. 49 ± 9 ml/m(2) (RV), p=0.001) and contractility (2.3 ± 0.8 (LV) vs. 1.9 ± 0.7 mmHg/ml/m(2) (RV), p=0.050) during rest and higher EF during dobutamine (63 ± 8 (LV) vs. 58 ± 10 ml/m(2) (RV), p=0.043). CONCLUSION Ventricular function is relatively well preserved in modern-day Fontan patients. With dobutamine stress there is a decrease in EDVi. ECC patients have higher CI and EF during stress. Patients with a dominant RV have lower systolic, including impaired contractility, and diastolic function.

Does functional health status predict health-related quality of life in children after Fontan operation?

PURPOSE It is important to identify those children with a Fontan circulation who are at risk for impaired health-related quality of life. We aimed to determine the predictive value of functional health status - medical history and present medical status - on both physical and psychosocial domains of health-related quality of life, as reported by patients themselves and their parents. METHODS We carried out a prospective cross-sectional multi-centre study in Fontan patients aged between 8 and 15, who had undergone staged completion of total cavopulmonary connection according to a current technique before the age of 7 years. Functional health status was assessed as medical history - that is, age at Fontan, type of Fontan, ventricular dominance, and number of cardiac surgical procedures - and present medical status - assessed with magnetic resonance imaging, exercise testing, and rhythm assessment. Health-related quality of life was assessed with The TNO/AZL Child Questionnaire Child Form and Parent Form. RESULTS In multivariate prediction models, several medical history variables, such as more operations post-Fontan completion, lower age at Fontan completion, and dominant right ventricle, and present medical status variables, such as smaller end-diastolic volume, a higher score for ventilatory efficiency, and the presence of sinus node dysfunction, predicted worse outcomes on several parent-reported and self-reported physical as well as psychosocial health-related quality of life domains. CONCLUSIONS Medical history and worse present medical status not only predicted worse physical parent-reported and self-reported health-related quality of life but also worse psychosocial health-related quality of life and subjective cognitive functioning. These findings will help in identifying patients who are at risk for developing impaired health-related quality of life.

Regional Ventricular Performance and Exercise Training in Children and Young Adults After Repair of Tetralogy of Fallot Randomized Controlled Pilot Study

Background—Public-health guidelines recommend patients with congenital heart disease to exercise. Studies have shown that patients with congenital heart disease can improve physical exercise capacity. The effect of training on regional ventricular performance has hardly been studied. We performed a pilot study to assess whether an exercise training program would result in adverse changes of regional ventricular performance in patients with corrected tetralogy of Fallot. Methods and Results—Multicenter prospective randomized controlled pilot study in patients with tetralogy of Fallot aged 10 to 25 years. A 12-week standardized aerobic dynamic exercise training program (3 one-hour sessions per week) was used. Pre- and post-training cardiopulmonary exercise tests, MRI, and echocardiography, including tissue-Doppler imaging, were performed. Patients were randomized to the exercise group (n=28) or control group (n=20). One patient in the exercise group dropped out. Change in tissue-Doppler imaging parameters was similar in the exercise group and control group (change in right ventricle free wall peak velocity E′ exercise group, 0.8±2.6 cm/s; control group, 0.9±4.1; peak velocity A′ exercise group, 0.4±2.4 m/s; control group 4.6±18.1 cm/s). Conclusions—This randomized controlled pilot study provides preliminary data suggesting that regional ventricular performance is well maintained during 3-month aerobic dynamic exercise training in children and young adults with repaired tetralogy of Fallot. This information might help patients adhere to current public-health guidelines. Clinical Trial Registration—URL: http//:www.trialregister.nl. Unique identifier: NTR2731.

Ventricular Response to Dobutamine Stress CMR Is a Predictor for Outcome in Fontan Patients

The Fontan operation is used to treat patients with a functional univentricular heart [(1)][1]. Long-term complications include circulatory failure, thromboembolic events, arrhythmias, and death [(1,2)][1]. Cardiovascular magnetic resonance (CMR) using exercise or pharmacological stress might

Regional Ventricular Performance and Exercise Training in Children and Young Adults After Repair of Tetralogy of FallotCLINICAL PERSPECTIVE: Randomized Controlled Pilot Study

Background—Public-health guidelines recommend patients with congenital heart disease to exercise. Studies have shown that patients with congenital heart disease can improve physical exercise capacity. The effect of training on regional ventricular performance has hardly been studied. We performed a pilot study to assess whether an exercise training program would result in adverse changes of regional ventricular performance in patients with corrected tetralogy of Fallot. Methods and Results—Multicenter prospective randomized controlled pilot study in patients with tetralogy of Fallot aged 10 to 25 years. A 12-week standardized aerobic dynamic exercise training program (3 one-hour sessions per week) was used. Pre- and post-training cardiopulmonary exercise tests, MRI, and echocardiography, including tissue-Doppler imaging, were performed. Patients were randomized to the exercise group (n=28) or control group (n=20). One patient in the exercise group dropped out. Change in tissue-Doppler imaging parameters was similar in the exercise group and control group (change in right ventricle free wall peak velocity E′ exercise group, 0.8±2.6 cm/s; control group, 0.9±4.1; peak velocity A′ exercise group, 0.4±2.4 m/s; control group 4.6±18.1 cm/s). Conclusions—This randomized controlled pilot study provides preliminary data suggesting that regional ventricular performance is well maintained during 3-month aerobic dynamic exercise training in children and young adults with repaired tetralogy of Fallot. This information might help patients adhere to current public-health guidelines. Clinical Trial Registration—URL: http//:www.trialregister.nl. Unique identifier: NTR2731.

Regional Ventricular Performance and Exercise Training in Children and Young Adults After Repair of Tetralogy of FallotCLINICAL PERSPECTIVE

Background—Public-health guidelines recommend patients with congenital heart disease to exercise. Studies have shown that patients with congenital heart disease can improve physical exercise capacity. The effect of training on regional ventricular performance has hardly been studied. We performed a pilot study to assess whether an exercise training program would result in adverse changes of regional ventricular performance in patients with corrected tetralogy of Fallot. Methods and Results—Multicenter prospective randomized controlled pilot study in patients with tetralogy of Fallot aged 10 to 25 years. A 12-week standardized aerobic dynamic exercise training program (3 one-hour sessions per week) was used. Pre- and post-training cardiopulmonary exercise tests, MRI, and echocardiography, including tissue-Doppler imaging, were performed. Patients were randomized to the exercise group (n=28) or control group (n=20). One patient in the exercise group dropped out. Change in tissue-Doppler imaging parameters was similar in the exercise group and control group (change in right ventricle free wall peak velocity E′ exercise group, 0.8±2.6 cm/s; control group, 0.9±4.1; peak velocity A′ exercise group, 0.4±2.4 m/s; control group 4.6±18.1 cm/s). Conclusions—This randomized controlled pilot study provides preliminary data suggesting that regional ventricular performance is well maintained during 3-month aerobic dynamic exercise training in children and young adults with repaired tetralogy of Fallot. This information might help patients adhere to current public-health guidelines. Clinical Trial Registration—URL: http//:www.trialregister.nl. Unique identifier: NTR2731.