Long-term follow-up in adults after tetralogy of Fallot repair

Characterizing the Use of Exercise Testing in Repaired Tetralogy of Fallot Patients: A Multi-Institutional Survey

Cardiopulmonary exercise testing (CPET) is an important tool used in the management of patients with congenital heart disease. However, there are no clear guidelines for its use in specific populations, such as repaired Tetralogy of Fallot (rTOF). We sought to characterize current practice patterns and attitudes regarding exercise testing in the rTOF population using an online survey distributed to pediatric cardiologists. Analyses were performed using qualitative statistics, Wilcoxon rank-sum, Kruskal-Wallis test, and chi-squared analysis. 103 clinicians completed the survey with 83% routinely sending symptomatic rTOF patients for exercise testing and 59% for asymptomatic patients. Respondents who routinely test asymptomatic patients reported higher levels of perceived helpfulness of exercise testing (p < 0.01) and comfort with CPET interpretation (p < 0.01). Although a large majority of respondents found exercise testing to be helpful (81% either "somewhat" or "very" helpful"), a considerably smaller portion indicated comfort with CPET interpretation (49% either "comfortable" or "very comfortable"). Nearly all respondents (92%) reported changing management primarily based on exercise testing results. However, the frequency of changes varied, with 10% "frequently", 62% "occasionally", 19% "rarely" changing management. There was a statistically significant relationship between the perceived helpfulness of exercise testing and the likelihood of management changes (p < 0.01). While exercise testing is used to make clinical decisions, our findings suggest that in some cases, management changes may be made without a similar degree of confidence in interpreting CPET findings. The variability in attitudes and practices highlights the need for evidence-based guidelines addressing exercise testing in rTOF, particularly for asymptomatic patients.

Pregnancy Considerations in Tetralogy of Fallot

The majority of women with repaired tetralogy of Fallot are able to tolerate pregnancy with a low risk of cardiovascular events. However, proactive contraceptive advice, prepregnancy counselling, and care by a pregnancy heart team with expertise in congenital heart disease are key to ensuring a good outcome for mother and baby. Maternal and fetal risks are increased in the presence of severe valvular stenosis, poorly tolerated arrhythmia, significant ventricular dysfunction, and cyanosis. It is unusual to see cyanotic adults with tetralogy of Fallot, whether unoperated or shunt palliated; pregnancy risks are greatly reduced by completing their repair before pregnancy is undertaken. The multidisciplinary pregnancy heart team should make a risk-stratified pregnancy care plan using a combination of published scoring systems and an individualized assessment of the patient's comorbidities. Low-risk patients may have the majority of their care and give birth in local units, whereas those at high risk should be managed and give birth in a tertiary centre with high-level expertise and intensive care facilities. Age-appropriate conversations about future childbearing and safe and reliable contraception should be part of routine follow-up from teenage years, so that women with tetralogy of Fallot can control their own fertility and make informed decisions about having children.

Health related quality of life in adults after late repair of tetralogy of fallot: experience from a low-middle income country

PURPOSE

Without neonatal screening in low middle-income countries like Pakistan, Tetralogy of Fallot (TOF) is a congenital heart disease which frequently remains untreated beyond infancy. The purpose of this study is to determine and assess outcomes and health related quality of life (HRQOL) in patients who undergo complete repair of TOF as adults.

METHODS

56 patients who underwent complete TOF repair after 16 years of age were included. Patient data was collected via retrospective chart review, and a semi structured interview along with Short-Form 36 (SF-36) questionnaire were used to assess HRQOL.

RESULTS

66.1% of patients were male with the mean age at surgery of 22.3 ± 6.00. All patients had a post-operative NYHA Classification of I or II, 94.6% had an ejection fraction of ≥ 50% and 28.6% showed small residual lesions in follow-up echocardiograms. 32.1% of patients suffered post-operative morbidity. For the quantitative assessment using SF-36 scores, patients showed good scores of median 95 (65-100). A major cause of delay to treatment was lack of consensus between treatments offered by doctors in different parts of Pakistan. There was a pattern of 'inability to fit in' among patients who had had late TOF repair, despite self- reported improved HRQOL.

CONCLUSION

Our results indicate that even with a delayed diagnosis, surgical repair of TOF produces good functional results. However, these patients face significant psychosocial issues. While early diagnosis remains the ultimate goal, patients undergoing late repair should be managed in more holistic manner with attention to psychological impact of the disease as well.

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.

Midterm prognosis following total correction of tetralogy of fallot in adult patients

Background

Tetralogy of Fallot is a common congenital heart disease characterized by cyanosis. The primary treatment approach involves corrective surgery typically performed within the first year of life to achieve complete resolution. However, certain patients may undergo surgery at an older age. This study seeks to assess the efficacy of surgery by examining the midterm outcomes of total correction of Tetralogy of Fallot when performed in older individuals.

Methods

This interventional-longitudinal study focused on patients who underwent complete surgery to correct tetralogy of Fallot at an advanced age of over 15 years. All of the participants were referred to the Shahid Rajaei Heart and Vascular Center, which is a referral center for congenital heart diseases in Iran, between 2010 and 2020. The surgical procedures for these patients involved primary total correction of tetralogy of Fallot or surgery following by shunt implantation. Prior to the surgery, the necessary information was gathered from the patients' medical records. The patients were then monitored over a 5-year period, during which they received regular check-ups from cardiologist with fellowship in adult congenital heart disease.

Results

A total of 94 participants were enrolled in the study, with an average age of 26.7 ± 9.6 years. Notably, the majority of the participants were male. The study reported a late mortality rate of 3.2%. Furthermore, 17 patients, constituting 18% of the cohort, underwent a secondary surgical procedure. This secondary surgery encompassed 14 cases of Pulmonary Valve Replacement (14.8%) and 3 cases of Ventricular Septal Defect repair (3.1%).

Conclusion

While the optimal age for total correction of Tetralogy of Fallot is conventionally considered to be within the first year of life, this study demonstrated that surgical intervention performed at a later stage of life can yield favorable midterm prognoses. It is imperative to emphasize that individuals unable to undergo surgery at the ideal age due to a multitude of factors should not be deprived of the potential benefits associated with surgical intervention.

Characterizing the Use of Exercise Testing in Repaired Tetralogy of Fallot Patients: A Multi-Institutional Survey

Long-term survival for repaired Tetralogy of Fallot (rTOF) is excellent. We achieve this by close clinical monitoring to stratify prognosis and guide clinical decision-making. Cardiopulmonary exercise stress testing (CPET) is used to help guide clinical decision making; however, there are no clear guidelines for its use in this population. We sought to describe practice variability with regards to exercise testing for rTOF patients and how exercise data is used to guide management. We distributed a survey to pediatric cardiologists via email. Analyses were performed using qualitative statistics, two-sample T-tests, and chi-squared analysis. One-hundred and three clinicians completed the survey with 83% reporting that they routinely send symptomatic rTOF patients for exercise testing and 59% for asymptomatic patients. Respondents who routinely test asymptomatic patients reported higher levels of perceived helpfulness of exercise testing (p = 0.04) and comfort with CPET interpretation (p = 0.03). Nearly all respondents (92%) reported changing management primarily based on exercise testing results, with 62% reporting "occasionally changing management" and 10% reporting "frequently changing management". Results indicated that exercise test results influenced clinical decisions, such as the timing of interventions, need for additional imaging, or the initiation of exercise interventions. There was a statistically significant relationship between the perceived helpfulness of exercise testing and the likelihood of management changes (p < 0.01). The variability in attitudes and practices highlights the need for evidence-based guidelines addressing exercise testing in rTOF, particularly for asymptomatic patients.

Biventricular shape modes discriminate pulmonary valve replacement in tetralogy of Fallot better than imaging indices

Current indications for pulmonary valve replacement (PVR) in repaired tetralogy of Fallot (rTOF) rely on cardiovascular magnetic resonance (CMR) image-based indices but are inconsistently applied, lead to mixed outcomes, and remain debated. This study aimed to test the hypothesis that specific markers of biventricular shape may discriminate differences between rTOF patients who did and did not require subsequent PVR better than standard imaging indices. In this cross-sectional retrospective study, biventricular shape models were customized to CMR images from 84 rTOF patients. A statistical atlas of end-diastolic shape was constructed using principal component analysis. Multivariate regression was used to quantify shape mode and imaging index associations with subsequent intervention status (PVR, n = 48 vs. No-PVR, n = 36), while accounting for confounders. Clustering analysis was used to test the ability of the most significant shape modes and imaging indices to discriminate PVR status as evaluated by a Matthews correlation coefficient (MCC). Geometric strain analysis was also conducted to assess shape mode associations with systolic function. PVR status correlated significantly with shape modes associated with right ventricular (RV) apical dilation and left ventricular (LV) dilation (p < 0.01), RV basal bulging and LV conicity (p < 0.05), and pulmonary valve dilation (p < 0.01). PVR status also correlated significantly with RV ejection fraction (p < 0.05) and correlated marginally with LV end-systolic volume index (p < 0.07). Shape modes discriminated subsequent PVR better than standard imaging indices (MCC = 0.49 and MCC = 0.28, respectively) and were significantly associated with RV and LV radial systolic strain. Biventricular shape modes discriminated differences between patients who did and did not require subsequent PVR better than standard imaging indices in current use. These regional features of cardiac morphology may provide insight into adaptive vs. maladaptive types of structural remodeling and point toward an improved quantitative, patient-specific assessment tool for clinical use.

Syndromic and Non-Syndromic Patients with Repaired Tetralogy of Fallot: Does It Affect the Long-Term Outcome?

Background: The impact of genetic syndromes on cardiac magnetic resonance imaging (cMRI) parameters, particularly on right and/or left ventricular dysfunction, associated with clinical parameters following the repair of Tetralogy of Fallot (rToF) is not well known. Therefore, this study aimed to assess the differences in clinical, surgical, and cMRI data in syndromic and non-syndromic rToF patients. Methods: All syndromic rToF patients undergoing a cMRI without general anesthesia between 2010 and 2020 who were able to match with non-syndromic ones for birth date, sex, type of surgery, timing of cMRI, and BSA were selected. Demographic, clinical, surgical, MRI, ECG, and Holter ECG data were collected. Results: A total of one hundred and eight rToF patients equally subdivided into syndromic and non-syndromic, aged 18.7 ± 7.3 years, were studied. Del22q11.2 and Down syndrome (DS) were the most frequent syndromes (42.6% and 31.5%, respectively). Regarding the cMRI parameters considered, left ventricular (LV) dysfunction (LVEF < 50%) was more frequently found in syndromic patients (p = 0.040). In addition, they were older at repair (p = 0.002) but underwent earlier pulmonary valve replacement (PVR) (15.9 ± 5.6 vs. 19.5 ± 6.0 years, p = 0.049). On multivariate Cox regression analysis, adjusted for age at first repair, LV dysfunction remained significantly more associated with DS than del22q11.2 and non-syndromic patients (HR of 5.245; 95% CI 1.709–16.100, p = 0.004). There were only four episodes of non-sustained ventricular tachycardia in our cohort. Conclusions: Among the cMRI parameters commonly taken into consideration in rToF patients, LV dysfunction seemed to be the only one affected by the presence of a genetic syndrome. The percentage of patients performing PVR appears to be similar in both populations, although syndromic patients were older at repair and younger at PVR. Finally, the number of arrhythmic events in rToF patients seems to be low and unaffected by chromosomal abnormalities.

Computational analysis of cardiac structure and function in congenital heart disease: Translating discoveries to clinical strategies

Increased availability and access to medical image data has enabled more quantitative approaches to clinical diagnosis, prognosis, and treatment planning for congenital heart disease. Here we present an overview of long-term clinical management of tetralogy of Fallot (TOF) and its intersection with novel computational and data science approaches to discovering biomarkers of functional and prognostic importance. Efforts in translational medicine that seek to address the clinical challenges associated with cardiovascular diseases using personalized and precision-based approaches are then discussed. The considerations and challenges of translational cardiovascular medicine are reviewed, and examples of digital platforms with collaborative, cloud-based, and scalable design are provided.

Huge right ventricular outflow tract aneurysm late following total repair of tetralogy of Fallot leading to orthotopic heart transplantation

Described herein are 3 patients who underwent successful orthotopic heart transplantation (OHT) because of huge, calcified right ventricular outflow tract (RVOT) aneurysms after repair of tetralogy of Fallot 35, 43, and 59 years earlier. Two of the 3 patients developed recurring episodes of ventricular tachycardia simulating arrhythmogenic right ventricular cardiomyopathy.

Dysregulation of Notch signaling in cardiac mesenchymal cells of patients with tetralogy of Fallot

BACKGROUND

Tetralogy of Fallot (TF) is a severe congenital defect of heart development. Fine-tuned sequential activation of Notch signaling genes is responsible for proper heart chamber development. Mutations in Notch genes have been associated with TF. The aim of this study was to analyze the activity of the Notch pathway in cardiac mesenchymal cells derived from ventricular tissue of TF patients.

METHODS

Cardiac mesenchymal cells were isolated from 42 TF patients and from 14 patients with ventricular septal defects (VSDs), used as a comparison group. The Notch pathway was analyzed by estimating the expression of Notch-related genes by qPCR. Differentiation and proliferation capacity of the cells was estimated.

RESULTS

The TF-derived cells demonstrated a dysregulated pattern of Notch-related gene expression comparing to VSD-derived cells. Correlation of Notch signaling activation level by HEY1/HES1 expression level with proliferation and cardiogenic-like differentiation of cardiac mesenchymal cells was observed but not with clinical parameters nor with the age of the patients.

CONCLUSIONS

The data suggest a contribution of dysregulated Notch signaling to the pathogenesis of tetralogy of Fallot and importance of Notch signaling level for the functional state of cardiac mesenchymal cells, which could be critical considering these cells for potential cell therapy approaches.

Identifying Risk Factors for Massive Right Ventricular Dilation in Patients With Repaired Tetralogy of Fallot

In repaired tetralogy of Fallot (rTOF), pulmonary insufficiency results in varying degrees of right ventricle (RV) dilation. A subset of patients is diagnosed at initial cardiac magnetic resonance imaging (CMR) with a massively dilated RV, far beyond pulmonary valve replacement (PVR) criteria, which is unlikely to return to normal size after PVR. This study aimed to identify risk factors for massive RV dilation at initial CMR. This nested case-control study included all patients at our institution with rTOF and massive RV dilation (indexed RV end-diastolic volume [RVEDVi] ≥200 ml/m²) on initial CMR. Patients were matched by age at first CMR, gender, and type of repair with rTOF controls with RVEDVi<200 ml/m². In 39 cases (median RVEDVi 227 ml/m², interquartile range [IQR] 213 to 250) and 73 controls (median RVEDVi 155 ml/m², IQR 130 to 169), repair at >6 months of age, longer QRS duration, and non-Caucasian race were significantly associated with massive RV dilation on univariate analysis. In multivariate analysis, repair at >6 months of age (adjusted odds ratio [AOR] 2.90, 95% confidence interval [CI] 1.12 to 7.55, p = 0.03), longer QRS duration (AOR = 1.03, 95% CI 1.01 to 1.05, p = 0.005), and non-Caucasian race (AOR = 7.84, 95% CI 1.76 to 34.8, p = 0.01) remained independently associated with massive RV dilation. Era of repair, history of systemic to pulmonary shunt palliation, genetic anomaly, and additional cardiac lesions did not differ between groups. In conclusion, these risk factors identify a subset of patients who may benefit from earlier CMR evaluation to avoid massive irreversible RV dilation.

4D flow MRI versus conventional 2D for measuring pulmonary flow after Tetralogy of Fallot repair

BACKGROUND

After tetralogy of Fallot (TOF) repair, pulmonary regurgitation and right ventricular function must be monitored. Conventional (2D) cardiac magnetic resonance (CMR) is currently the clinical reference method for measuring pulmonary regurgitation. However, 4DFlow CMR has been reported to provide a more comprehensive flow analysis than 2D CMR. We aimed to compare 4DFlow CMR to 2D CMR for assessing pulmonary regurgitation and flow, as well as aortic flow, in children and adults after surgical repair of TOF.

METHODS

Retrospective analysis of patients with repaired TOF admitted for cardiac MRI with 4DFlow acquisition from 2016 to 2018. Linear regression was used to assess correlations and Bland-Altman analyses were performed.

RESULTS

The 60 included patients had a mean age of 18.2 ± 10.4 years (range, 2-54 years). Significant correlations between the two techniques were found for pulmonary regurgitant fraction (R [2] = 0.6642, p < 0.0001), net pulmonary flow (R [2] = 0.6782, p < 0.0001), forward pulmonary flow (R [2] = 0.6185, p < 0.0001), backward pulmonary flow (R [2] = 0.8192, p < 0.0001), and aortic valve flow (R [2] = 0.6494, p < 0.0001). The Bland-Altman analysis showed no significant bias, narrow limits of agreement, and few scattered points. The correlation between pulmonary and aortic flow was better with 4DFlow CMR than with 2D CMR (R [2] = 0.8564, p < 0.0001 versus R [2] = 0.4393, p < 0,0001, respectively). Interobserver reliability was good.

CONCLUSION

These results establish the feasibility and reliability of 4DFlow CMR for assessing pulmonary flow in a large paediatric and adult population with repaired TOF. 4DFlow CMR may be more reliable than 2D MRI for pulmonary flow assessment after TOF repair.