Early age at repair prevents restrictive right ventricular (RV) physiology after surgery for tetralogy of Fallot (TOF): diastolic RV function after TOF repair in infancy

Neurodevelopment in patients with repaired tetralogy of Fallot

Neurodevelopmental sequelae are prevalent and debilitating for patients with congenital heart defects. Patients born with tetralogy of Fallot (TOF) are susceptible for abnormal neurodevelopment as they have several risk factors surrounding the perinatal and perioperative period. Some risk factors have been well described in other forms of congenital heart defects, including transposition of the great arteries and single ventricle heart disease, but they have been less studied in the growing population of survivors of TOF surgery, particularly in infancy and childhood. Adolescents with TOF, even without a genetic syndrome, exhibit neuro-cognitive deficits in executive function, visual-spatial skills, memory, attention, academic achievement, social cognition, and problem-solving, to mention a few. They also have greater prevalence of anxiety disorder, disruptive behavior and attention-deficit hyperactivity disorder. These deficits impact their academic performance, social adjustment, and quality of life, thus resulting in significant stress for patients and their families. Further, they can impact their social adjustment, employment and career development as an adult. Infants and younger children can also have significant deficits in gross and fine motor skills, cognitive deficits and abnormal receptive language. Many of the risk factors associated with abnormal neurodevelopment in these patients are not readily modifiable. Therefore, patients should be referred for evaluation and early intervention to help maximize their neurodevelopment and improve overall outcomes. More study is needed to identify potentially modifiable risk factors and/or mediators of neurodevelopment, such as environmental and socio-economic factors.

Use of Cardiovascular Magnetic Resonance for Risk Stratification in Repaired Tetralogy of Fallot

The risk of premature death in adult patients with repaired tetralogy of Fallot is real and not inconsiderable. From the third decade of life, the incidence of malignant ventricular arrhythmia (VA) is known to exponentially rise. Progressive adverse mechanoelectrical modelling because of years of volume and/or pressure overload from residual pulmonary valve dysfunction and ventricular scar creates the perfect catalyst for VA. Although potentially lifesaving, implantable cardiac defibrillators are associated with substantial psychological and physical morbidity. Better selection of patients most at risk of VA, so that implantable cardiac defibrillators are not inflicted on patients who will never need them, is therefore crucial and has inspired research on this topic for several decades. Cardiovascular magnetic resonance (CMR) enables noninvasive, radiation-free clinical assessment of anatomy and function, making it ideal for the lifelong surveillance of patients with congenital heart disease. Gold standard measurements of ventricular volumes and systolic function can be derived from CMR. Tissue characterization using CMR can identify a VA substrate and provides insight into myocardial disease. We detail risk factors for VA identified using currently available CMR techniques. We also discuss emerging and advanced CMR techniques that have not all yet translated into routine clinical practice. We review how CMR-defined predictors of VA in repaired tetralogy of Fallot can be incorporated into risk scores with other clinical factors to improve the accuracy of risk prediction and to allow for pragmatic clinical application. Finally, we discuss what the future may hold.

Right atrial function early after tetralogy of Fallot repair

Diastolic dysfunction after repair for Tetralogy of Fallot (TOF) is associated with adverse long-term outcomes. Right atrial (RA) mechanics as a proxy of right ventricular (RV) diastolic function in the early post-operative period after surgical repair for TOF has not been reported. We sought to evaluate RA and RV strain prior to hospital discharge after TOF repair and to identify important patient factors associated with strain using a machine learning method. Single center retrospective cohort study of TOF patients undergoing surgical repair, with analysis of RA and RV strain from pre-and post-operative echocardiograms. RA function was assessed by the peak RA strain, systolic RA strain rate, early diastolic RA strain rate and RA emptying fraction. RV systolic function was measured by global longitudinal strain. Pre- and post-operative values were compared using Wilcoxon rank sum test. Gradient boosted machine (GBM) models were used to identify the most important predictors of post-operative strain. In total, 153 patients were enrolled, median age at TOF repair 3.5 months (25th-75th percentile: 2.2- 5.2), mostly male (67%), and White (64.1%). From pre-to post-operative period, there was significant worsening in all RA parameters and in RV strain. GBM models identified patient, anatomic, and surgical factors that were strong predictors of post-operative RA and RV strain. These factors included pulmonary valve and branch pulmonary artery Z scores, birth weight, gestational age and age at surgery, pre-operative RV fractional area change and oxygen saturation, type of outflow tract repair, duration of cardiopulmonary bypass, and early post-operative partial arterial pressure of oxygen. There is significant worsening in RA and RV strain early after TOF repair, indicating early alteration in diastolic and systolic function after surgery. Several patient and operative factors influence post-operative RV function. Most of the factors described are not readily modifiable, however they may inform pre-operative risk-stratification. The clinical application of RA strain and the prognostic implication of these early changes merit further study.

End-Diastolic Forward Flow and Restrictive Physiology in Repaired Tetralogy of Fallot: A Systematic Review and Meta-Analysis

Background

Pulmonary arterial end‐diastolic forward flow (EDFF) following repaired tetralogy of Fallot has been thought to represent right ventricular (RV) restrictive physiology, but is not fully understood. This systematic review and meta‐analysis sought to clarify its physiological and clinical correlates, and to define a framework for understanding EDFF and RV restrictive physiology.

Methods and Results

PubMed/MEDLINE, Embase, Scopus, and reference lists of relevant articles were searched for observational studies published before March 2021. Random‐effects meta‐analysis was performed to identify factors associated with EDFF. Forty‐two individual studies published between 1995 and 2021, including a total of 2651 participants (1132 with EDFF; 1519 with no EDFF), met eligibility criteria. The pooled estimated prevalence of EDFF among patients with repaired tetralogy of Fallot was 46.5% (95% CI, 41.6%–51.3%). Among patients with EDFF, the use of a transannular patch was significantly more common, and their stay in the intensive care unit was longer. EDFF was associated with greater RV indexed volumes and mass, as well as smaller E‐wave velocity at the tricuspid valve. Finally, pulmonary regurgitation fraction was greater in patients with EDFF, and moderate to severe pulmonary regurgitation was more common in this population.

Conclusions

EDFF is associated with dilated, hypertrophied RVs and longstanding pulmonary regurgitation. Although several studies have defined RV restrictive physiology as the presence of EDFF, our study found no clear indicators of poor RV compliance in patients with EDFF, suggesting that EDFF may have multiple causes and might not be the precise equivalent of RV restrictive physiology.

Does interatrial communication affect post-operative course of children undergoing tetralogy of Fallot repair? Single centre retrospective cohort study: propensity score matching

INTRODUCTION

During tetralogy of Fallot repair, leaving or even create an interatrial communication may facilitate post-operative course particularly with right ventricle restrictive physiology. The aim of our study is to assess the influence of atrial communication on post-operative course of tetralogy of Fallot repair.

METHODS

Retrospectively, we studied all children who had tetralogy of Fallot repair (2003-2018). We divided them into two groups: tetralogy of Fallot repair with interatrial communication (TOFASD) group and tetralogy of Fallot repair with intact atrial septum (TOFIAS) group. We performed propensity match score for specific pre- or intra-operative variables and compared groups for post-operative outcome variables. Secondarily, we looked for right ventricle restrictive physiology incidence and influence of early repair performed before 3 months of age on post-operative course.

RESULTS

One hundred and sixty children underwent tetralogy of Fallot repair including (93) cases of TOFIAS (58%) and (67) cases of TOFASD (42%). With propensity matching score, 52 patients from each group were compared. Post-operative course was indifferent in term of positive pressure ventilation time, vasoactive inotropic score, creatinine and lactic acid levels, duration and amount of chest drainage and length of intensive care unit and hospital stay. Right ventricle restrictive physiology occurred in 38% of patients with no effects on outcome. 12/104 patients (12%) with early repair needed longer pressure ventilation time (p = 0.003) and intensive care unit stay (p = 0.02).

CONCLUSION

Leaving interatrial communication in tetralogy of Fallot repair did not affect post-operative course. As well, right ventricle restrictive physiology did not affect post-operative course. Infants undergoing early tetralogy of Fallot repair may require longer duration of positive pressure ventilation time and intensive care unit stay.

Echocardiographic predictors of severe right ventricular diastolic dysfunction in tetralogy of Fallot: Relations to patient outcomes

BACKGROUND

Previous studies have described echocardiographic indices of right ventricular (RV) diastolic function in patients with tetralogy of Fallot (TOF) but these indices have not been validated against invasive hemodynamic data. The purpose of this study was to determine echocardiographic predictors of severe RV diastolic dysfunction, and the impact of severe RV diastolic dysfunction on transplant-free survival.

METHODS

Cohort study of TOF patients that underwent non-simultaneous cardiac catheterization and echocardiogram at Mayo Clinic. Based on prior studies we selected these indices for assessment: tricuspid E/A, E/e', deceleration time, pulmonary artery forward flow, dilated inferior vena cava (IVC), and hepatic vein diastolic flow reversal (HVDFR). RV diastolic function classes (normal, mild/moderate and severe dysfunction) were created using arbitrary cut-off points of the median values of right ventricular end-diastolic pressure (RVEDP) and right atrial pressure (RAP) for the cohort.

RESULTS

Among 173 patients (age 40 ± 13 years), 68 patients were classified as normal (RVEDP≤14 and RAP≤10), 37 as mild/moderate dysfunction (either RVEDP>14 or RAP>10), and 69 as severe dysfunction (RVEDP>14 and RAP>10). Of the indices assessed, dilated IVC had the best sensitivity of 95% (area under the curve [AUC] 0.689) while HVDFR had the best specificity of 69% (AUC 0.648) for detecting severe RV diastolic dysfunction. Severe RV diastolic dysfunction was an independent risk factor for death/transplant (hazard ratio 2.83, p = 0.009).

CONCLUSION

Severe RV diastolic dysfunction, as defined by invasive hemodynamic indices, was associated with poor prognosis. Echocardiographic indices can identify these high risk patients, and hence improve risk stratification in clinical practice.

Timing of Repair in Tetralogy of Fallot: Effects on Outcomes and Myocardial Health

Early complete repair of tetralogy of Fallot (ToF) prior to 1 year of age has been demonstrated to be safe and has survival benefits over late repair. The age at repair of ToF affects long-term outcomes. This may largely be related to preserved, or comparatively better, myocardial health. Most studies advocate for an age of repair between 3 and 6 months and certainly below the age of 1 year. Patients with severe right ventricular outflow tract obstruction represent an exception to this rule and may require neonatal repair or surgical and catheter-based palliation before surgery. Older age at repair beyond the first birthday leads to unfavorable right ventricular remodeling with increased right ventricular stiffness and hypertrophy and is associated with increased long-term ventricular tachycardia and all-cause mortality. In this article, we review the short- and long-term benefits of early repair, with a focus on long-term morbidity. In conclusion, we emphasize the importance of myocardial health and the relationship to early repair and advocate for the use of magnetic resonance imaging in adult patients with repaired ToF to detect myocardial fibrosis.

Pathophysiologic and Prognostic Implications of Right Atrial Hypertension in Adults With Tetralogy of Fallot

Background

Right atrial pressure (RAP), a composite metric of right ventricular diastolic function, volume status, and right heart compliance, is a predictor of mortality in patients with heart failure due to acquired heart disease. Because patients with tetralogy of Fallot (TOF) might have abnormal right atrial and ventricular mechanics caused by myocardial injury and remodeling, we hypothesized that RAP would be associated with disease severity and cardiovascular adverse events in this population.

Methods and Results

We performed a cohort study of adults with TOF who underwent right heart catheterization at the Mayo Clinic Rochester between 1990 and 2017. The objective was to determine the association between RAP and multiple domains of disease severity in TOF (percentage of predicted peak oxygen consumption, atrial or ventricular arrhythmia, and heart failure hospitalization), as well as cardiovascular adverse events, defined as sustained ventricular tachycardia, resuscitated or aborted sudden death, heart transplantation, or death. Among 225 patients (113 male; mean age: 39±14 years), mean RAP was 10.7±5.2 mm Hg and median was 10 mm Hg (interquartile range: 7–13 mm Hg). Increasing RAP was associated with atrial or ventricular arrhythmias (odds ratio: 5.01; 95% CI, 1.22–23.49; P<0.001), heart failure hospitalization (odds ratio: 1.47; 95% CI, 1.10–2.39; P=0.033) per 5 mm Hg, and worsening exercise capacity (peak oxygen consumption; R²=0.74, r=−0.86, P<0.001). RAP was a predictor of cardiovascular adverse events (hazard ratio: 1.28; 95% CI, 1.10–1.47; P=0.028) per 5 mm Hg.

Conclusions

In symptomatic patients with TOF, increasing RAP correlates with multiple domains of disease severity (risk stratification) and predicts future cardiovascular events (prognostication). These data have potential clinical implications in the target population of symptomatic TOF patients.

Symptomatic Tetralogy of Fallot in Young Infants: Primary Repair or Shunt-Pediatric Health Information System Database Analysis

BACKGROUND

Compare the early outcomes and hospital charges of early primary repair and systemic-to-pulmonary artery shunt for neonates and young infants (≤90 days of age) with tetralogy of Fallot using data from the Pediatric Health Information System database.

METHODS

The Pediatric Health Information System database was queried for patients <90 days of age with primary diagnosis of tetralogy of Fallot who underwent nonelective surgical repair or palliation between January 2008 and December 2014. The initial cohort of 821 patients (group 1 early primary repair, N = 554; group 2 systemic-to-pulmonary artery shunt, N = 267) was propensity score matched (248 patients in each group) to account for baseline imbalances in age and prostaglandin use.

RESULTS

Comparison of unmatched groups revealed younger age and higher incidence of extracardiac anomalies ( P = .02) and prematurity ( P = .04) in group 2. Mortality was comparable between the groups (group 1: 20 [4%] of 554 vs group 2: 11 [4%] of 267, P = .74). Irrespective of the type of procedure, prematurity (odds ratio [OR] = 3.3, 95% confidence interval [CI]: 1.5-7.4) and extracardiac anomalies (OR = 2.5, 95% CI: 1.2-5.3) were independent risk factors for mortality. Propensity score-matched analysis revealed no significant differences in patient mortality ( P = 1), duration of ventilation ( P = .64), hospital length of stay ( P = .69), or hospital charges ( P = .08) between the two groups.

CONCLUSION

Outcomes and hospital charges associated with nonelective early primary repair are comparable to systemic-to-pulmonary artery shunt in symptomatic patients <90 days old with tetralogy of Fallot.

Usefulness of Pulmonary Arterial End-Diastolic Forward Flow Late After Tetralogy of Fallot Repair to Predict a "Restrictive" Right Ventricle

The functional significance of pulmonary arterial end-diastolic forward flow (EDFF) in patients with repaired tetralogy of Fallot (rTOF) is not fully understood, with conflicting reports regarding its associations with pulmonary regurgitation (PR), right ventricular (RV) size and function, and so-called restrictive RV physiology. To examine these associations, we retrospectively analyzed 399 patients with rTOF who had contemporaneous echocardiography (Echo) and cardiovascular magnetic resonance (CMR) studies. The median age at TOF repair was 0.7 years (0.21, 2.66), age at CMR was 19.8 years (13.0, 29.4), and interval between Echo and CMR was 48 days (0, 182). Doppler identified EDFF in 122 (31%) patients and CMR in 113 patients (28%). Compared with those without EDFF, patients with EDFF were younger, had greater PR, and higher RV end-diastolic volume, stroke volume, and ejection fraction. Markers of RV restriction such as right atrial size did not differ between groups. On multivariable regression, EDFF was associated with higher RV stroke volume and lower left ventricular end-diastolic volume. The association between Echo and CMR measurements of EDFF was modest (area under the receiver operating characteristic curve = 0.684, r = 0.374, p < 0.001). In conclusion, EDFF was common in this large cohort of patients with rTOF, but its presence and extent varied between Echo and CMR. EDFF was associated with greater PR and larger RV size, but not with markers of poor RV compliance such as right atrial enlargement. Mechanisms beyond RV noncompliance may contribute to the presence of EDFF.

Clinical Progress in the Management of Tetralogy of Fallot in the Dominican Republic: A Case Series

BACKGROUND

Definitive surgical interventions for Dominican children with congenital heart disease, like those of other low- and middle-income countries, have been historically limited.

METHODS

We undertook review of a case series focusing on the surgical correction of complex forms of tetralogy of Fallot at a single center, CEDIMAT Centro Cardiovascular, in the Dominican Republic, over a 30-month period.

RESULTS

According to our criteria, 43 cases were determined to be complex tetralogy of Fallot repairs from the two-year period. Besides tetralogy of Fallot, the cohort had an additional 55 anatomic anomalies that had to be addressed at the time of surgery. Median age at the time of surgery was notably 30 months, and an average of 42 months elapsed from the time of diagnosis to the time of surgery for this group. Only 33% of the cases reviewed had no hypercyanotic crises before repair. Median time to extubation for this group of patients was one day, with a three-day median length of stay in the intensive care setting.

CONCLUSIONS

Our study importantly captures the present experience of a surgical congenital heart program that has recently transitioned from a traditional "mission model" to a now self-sustaining local practice. Both the number and the complexity of the lesions corrected in this caseload represent an advance from the level of care previously provided to children in the Dominican Republic.

Restrictive right ventricular performance assessed by cardiac magnetic resonance after balloon valvuloplasty of critical pulmonary valve stenosis

BACKGROUND

Little data are published about right ventricular diastolic performance in patients with critical pulmonary valve stenosis after balloon pulmonary valvuloplasty thus far.

METHODS

A total of 44 patients with isolated critical pulmonary valve stenosis who had undergone balloon valvuloplasty with haemodynamic recordings were enrolled to the study; 33 patients who came for follow-up underwent further imaging by echocardiography after 6 months and their right ventricular functional parameters were compared with 33 control patients of the same age and sex. Out of 33 patients, 21 underwent cardiac MRI with late gadolinium enhancement to assess the presence of right ventricular fibrosis.

RESULTS

The right ventricular systolic pressure (p<0.0001) and right ventricular outflow tract gradient (p<0.0001) decreased acutely (p<0.0001) after balloon valvuloplasty. During follow-up, M-mode left ventricular end diastolic dimension (p<0.001) and end systolic dimension increased (p<0.001), whereas right ventricular end diastolic dimension decreased (p<0.001). Compared with controls, patients (n=33) had significantly reduced tricuspid annular Ea and higher E/Ea (p<0.001). Right ventricular systolic dysfunction was also suggested by reduced tricuspid annular systolic velocity (p<0.001). Late gadolinium enhancement was demonstrated in 13 out of 21 patients with restrictive physiology, which involves the anterior right ventricular outflow tract, anterior wall, and inferior wall. The right ventricular late gadolinium enhancement score correlated positively with age (r=0.7, p<0.001) and right ventricular mass index (r=0.52, p<0.001).

CONCLUSION

The persistence of right ventricular diastolic dysfunction after relief of chronic pressure overload of critical pulmonary valve stenosis suggests that a factor - other than increase in afterload - is involved in this physiology. Fibrosis is the most likely factor responsible for persistence of restrictive physiology as documented by late gadolinium enhancement.

Distinctive Hemodynamics in the Immediate Postoperative Period of Patients with a Longer Cardiac Intensive Care Stay Post-Tetralogy of Fallot Repair

OBJECTIVE

After complete surgical repair the majority of tetralogy of Fallot (ToF), patients stay ≤2 days in the Cardiac Intensive Care Unit (CICU) while some may stay longer. We undertook this study to investigate the factors associated with shorter vs. longer length of stay in the CICU to help manage resources effectively.

DESIGN

Patients who underwent ToF repair at Aga Khan University, Pakistan, between July 2006 and December 2011 were studied in a case-control design. Clinical parameters were compared between short stay group (SSG) (≤2 days) and long stay group (LSG) (>2 days). Odds ratios were calculated, and regression was performed.

RESULTS

Ninety-eight patients (LSG 65, SSG 33) were included. Patients with lower preoperative saturation were 2.67 times more likely to be in the LSG group (P = .02). At 4 hours postoperatively, patients with a higher inotropic score (odds ratio [OR] = 3.03, confidence interval [CI] = 1.19-7.7, P = .02), higher central venous pressure (OR = 3.04, CI = 1.27-7.32, P = .013), and significant tachycardia at 4 hours (OR = 3.5, CI = 1.19-10.3. P = .02) were at risk for having a prolonged CICU stay. On multivariate analysis, significant postoperative tachycardia at 4 hours (z-score ≥3) was highly specific (sensitivity = 38.5%, specificity = 84.9%) for predicting the chances of being in the LSG. Other predictors included preop O(2) saturation ≤82.5% (sensitivity = 61.1%, specificity = 63.0%) and CVP ≥10 mm Hg at 4 hours (sensitivity = 55.4%, specificity = 71.9%).

CONCLUSION

Patients who end up staying longer in the CICU have features that are distinctive in the immediate postoperative period, and this can help clinicians in identifying patients who may need more support.

Echocardiographic assessment after surgical repair of tetralogy of fallot

Surgical correction of tetralogy of Fallot is still one of the most frequently performed intervention in pediatric cardiac surgery, and in many cases, it is far from being a complete and definitive correction. It is rather an excellent palliation that solves the problem of cyanosis, but predisposes the patients to medical and surgical complications during follow-up. The decision-making process regarding the treatment of late sequel is among the most discussed topics in adult congenital cardiology. In post-operative Fallot patients, echocardiography is used as the first method of diagnostic imaging and currently allows both a qualitative observation of the anatomical alterations and a detailed quantification of right ventricular volumes and function, of the right ventricular outflow tract, and of the pulmonary valve and pulmonary arteries. The literature introduced many quantitative echocardiographic criteria useful for the understanding of the pathophysiological mechanisms involving the right ventricle and those have made much more objective any decision-making processes.

Pulmonary Valve Replacement With a Bovine Pericardial Valve

Objectives:

From a population of 90 patients after pulmonary valve replacement with a biological valve (Carpentier-Edwards Perimount valve), 56 of 80 available patients were examined five years after surgery.

Background:

Pulmonary valve replacement is needed in many patients with congenital heart disease. Homografts have limited availability and predictable degeneration, and mechanical valves require anticoagulation. No superiority of one kind of pulmonary valve replacement has been shown. Biological valves that are readily available are being used and evaluated in increasing numbers.

Methods:

In this cross-sectional study, five years following surgery, data were gathered from hospital charts, echocardiography, stress echocardiography, magnetic resonance imaging, and exercise testing.

Results:

In 90 patients, there were three new valve replacements, one early cardiac death, and four late noncardiac deaths. Echocardiographic assessment of the study group showed pulmonary Doppler velocities (m/s) before, after operation, and at five-year follow-up of 2.8 ± 1.1, 1.6 ± 0.4, and 2.3 ± 0.7, respectively. The assessed insufficiencies (0-3) at the same times were 2.3 ± 1.0, 0.3 ± 0.4, and 1.1 ± 0.8. Maximal oxygen uptake increased from 65.6% ± 10.1% to 77.1% ± 18.2% of predicted and QRS width increased by 7 ± 23ms. Valve degeneration could be associated with young age but not with diagnosis or valve size.

Conclusion:

In our study, the biological valve in the pulmonary position showed excellent mid-term results with few reoperations, low gradients, and mild to moderate insufficiency. Oversizing, in contrast to young age, was not a risk factor for valve degeneration. In younger patients, this allows later percutaneous replacement, reducing the need for further surgery. However, longer follow-up is needed.

Routine primary repair of tetralogy of Fallot in the neonate

Uncertainty surrounds both the timing and ideal form of early management of tetralogy of Fallot. Some centers perform early complete repair in all patients regardless of age, symptoms and morphology. Others recommend a two-stage approach involving initial palliation in symptomatic neonates and young infants and those with unfavorable anatomy (anomalous coronary anatomy or hypoplastic pulmonary arteries). Advantages of early anatomic correction include alleviation of cyanosis, normal growth and organ development, removal of stimulus for right ventricular hypertrophy and avoidance of risks associated with initial palliation. With recent advances in anesthetic, operative and postoperative management, routine primary repair of tetralogy of Fallot in the neonate and young infant can be accomplished with excellent early and mid-term results. However, long-term follow-up is necessary to assess the impact of early repair on late right ventricular function, arrhythmias and need for reintervention.

Pulmonary stenosis and pulmonary regurgitation: both ends of the spectrum in residual hemodynamic impairment after tetralogy of Fallot repair

Repair of tetralogy of Fallot (TOF) has shown excellent outcomes. However it leaves varying degrees of residual hemodynamic impairment, with severe pulmonary stenosis (PS) and free pulmonary regurgitation (PR) at both ends of the spectrum. Since the 1980s, studies evaluating late outcomes after TOF repair revealed the adverse impacts of residual chronic PR on RV volume and function; thus, a turnaround of operational strategies has occurred from aggressive RV outflow tract (RVOT) reconstruction for complete relief of RVOT obstruction to conservative RVOT reconstruction for limiting PR. This transformation has raised the question of how much residual PS after conservative RVOT reconstruction is acceptable. Besides, as pulmonary valve replacement (PVR) increases in patients with RV deterioration from residual PR, there is concern regarding when it should be performed. Regarding residual PS, several studies revealed that PS in addition to PR was associated with less PR and a small RV volume. This suggests that PS combined with PR makes RV diastolic property to protect against dilatation through RV hypertrophy and supports conservative RVOT enlargement despite residual PS. Also, several studies have revealed the pre-PVR threshold of RV parameters for the normalization of RV volume and function after PVR, and based on these results, the indications for PVR have been revised. Although there is no established strategy, better understanding of RV mechanics, development of new surgical and interventional techniques, and evidence for the effect of PVR on RV reverse remodeling and its late outcome will aid us to optimize the management of TOF.

Is there any need for a shunt in the treatment of tetralogy of Fallot with one source of pulmonary blood flow?

OBJECTIVES

In symptomatic patients, performing a primary repair of tetralogy of Fallot (TOF), irrespective of age or placing a shunt, remains controversial. The aim of the study was to analyse the policy of primary correction.

METHODS

Between May 2005 and May 2012, a total of 87 consecutive patients with TOF, younger than 6 months of age, underwent primary correction. All patients had one source of pulmonary blood flow, with or without a patent ductus arteriosus. The median age at surgery was 106 ± 52.3 days (8-180 days). Twelve patients (13.8%) were newborns. Two groups were analysed: group I, patients <1 month of age; group II, patients between 2-6 months of age.

RESULTS

There was no early or late death at 7 years of follow-up. There was no difference in bypass time or hospital stay between the two groups, but the Aristotle comprehensive score (P < 0.0001), ICU stay (P = 0.030) and the length of ventilation (P = 0.014) were significantly different. Freedom from reoperation was 87.3 ± 4.3% and freedom from reintervention was 85.9 ± 4.2% at 7 years, with no difference between the two groups. Neurological development was normal in all patients, but 1 patient in Group II had cerebral seizures and showed developmental delay. Growth was adequate in all patients, except those with additional severe non-cardiac malformations that caused developmental delay. Eighty-five per cent of the patients were without cardiac medication.

CONCLUSIONS

Even in symptomatic neonates and infants <6 months of age, primary repair of TOF can be performed safely and effectively. One hundred per cent survival at 7 years suggests that early primary repair causes no increase in mortality in the modern era. Shunting is not necessary, even in symptomatic newborns, thus avoiding the risk of shunt-related complications and repeated hospital stays associated with a staged approach.

Restrictive right ventricular physiology after tetralogy of Fallot repair is associated with fibrosis of the right ventricular outflow tract visualized on cardiac magnetic resonance imaging

AIMS

To determine whether the restrictive physiology seen in Tetralogy of Fallot (TOF) patients can be explained by fibrosis of the right ventricular (RV) outflow tract. The aetiology for restrictive RV physiology after TOF repair is not known.

METHODS AND RESULTS

TOF patients (n = 31, 13 girls, 10.2 years ± 2.8) were included 9.2 ± 2.9 years after total correction and examined with cardiac magnetic resonance (CMR) and Doppler echocardiography. Cine, flow, and late gadolinium contrast enhanced (LGE) CMR imaging were performed to quantify RV volumes, pulmonary flow and regurgitation (PR), and fibrosis. Healthy children (n = 12) were investigated with CMR of the pulmonary flow. Forward flow during atrial contraction above mean + 2 SD of healthy subjects was set as a marker of restrictive physiology. Four patients were excluded due to suboptimal LGE-CMR. Fisher's exact test was used to determine the association between restrictive physiology and fibrosis. Sixteen patients showed fibrosis in the right ventricular outflow tract (RVOT) on LGE-CMR and 14 of them showed restrictive physiology on CMR. Of the 11 patients without fibrosis in the RVOT, 1 showed restrictive physiology. The odds ratio for RVOT fibrosis in patients with restrictive RV physiology was 70.0 (CI: 5.6-882.7, P < 0.001). The transannular patch repair did not differ between the groups (P = 0.37). The degree of RVOT fibrosis correlated positively with PR (r(2) = 0.38, P < 0.001) and RV volumes (r(2) = 0.51 for end-diastolic volume and r(2) = 0.47 for end-systolic volume, P < 0.001).

CONCLUSION

There is a strong association between the restrictive RV physiology detected on CMR and fibrosis of the RVOT in children after TOF repair.

Assessment of a right-ventricular infundibulum-sparing approach in transatrial-transpulmonary repair of tetralogy of Fallot

OBJECTIVE

The study aimed to evaluate the outcome of transatrial-transpulmonary repair of tetralogy of Fallot in relation to a right-ventricular outflow tract (RVOT)-sparing surgery.

METHODS

Based on the surgical management of right-ventricular outflow tract obstruction (RVOTO) at repair of tetralogy of Fallot, 140 children were retrospectively divided into three groups: (1) pulmonary valve (PV)-sparing, (2) infundibulum-sparing and (3) extended trans-annular patch (TAP). Clinical and echocardiographic outcome was assessed with regards to three equally divided study time eras between January 1994 and June 2010.

RESULTS

Over a 15-year study period, median age decreased from 11 (2-101) to 5 (1-11) months (p<0.001), whereas type of RVOT repair changed significantly between the first and the last era (group 1: 18-40%, group 2: 25-40% vs group 3: 57-20% (p=0.002)). Mortality was 0%. Complications were mainly related to clinical restrictive RV physiology (27%) and arrhythmia (10%). This cardiac morbidity remained constant over the eras and was associated with younger age (p=0.04), increased postoperative right ventricle/left ventricle (RV/LV) pressure ratio (p=0.01) and type of RVOT repair at the cost of TAP (p=0.03). Median follow-up of 8 years (1-16 years) showed an overall freedom from RVOT re-operation of 84% and 73%, respectively at 5 and 10 years. Most re-operations were for residual/recurrent RVOTO (12%) occurring more frequently in the latter era: 16% versus 7% in era 1 (p=0.08). Late echocardiographic evaluation revealed a strong correlation between severity of pulmonary regurgitation and increased RV/LV size ratio, which was mainly determined by increased TAP length (p<0.001) and duration of follow-up (p=0.06).

CONCLUSION

In a 15-year's experience with transatrial-transpulmonary correction of tetralogy of Fallot, a valve- and infundibulum-sparing approach has been advanced by lowering the age for elective repair. This change has been performed without compromising immediate clinical outcome, despite an increased early re-operation rate for residual obstruction. However, longer follow-up will disclose whether this approach is protective against progressive and late RV dysfunction.

Determinants and functional impact of restrictive physiology after repair of tetralogy of Fallot: new insights from magnetic resonance imaging

BACKGROUND

The presence of end-diastolic forward flow (EDFF) in the pulmonary arteries is commonly regarded as a hallmark of restrictive physiology of the right ventricle (RV) which, in turn, has been associated with a better long-term prognosis in patients after TOF repair. However, controversy persists over the beneficial clinical consequences of restrictive physiology. We aimed at determining the clinical relevance of restrictive physiology late after TOF repair.

METHODS

Fifty magnetic resonance examinations of 50 patients (age 13.0 ± 2.8 years, 26 males) with repaired TOF were evaluated. The patients were divided into: Group-1 with and Group-2 without EDFF; Group-A with smaller RVs (<170 ml/m2) and Group-B with larger RVs (≥ 170 ml/m2). Maximum oxygen consumption as percent of predicted (VO2max-pred) at a recent exercise test was recorded.

RESULTS

Groups-1 and 2 did not differ with regard to their right ventricular end-diastolic volume, pulmonary regurgitant volume, or QRS duration. Patients in Group-1 had a higher VO2max-pred than patients in Group-2 (70.3% versus 54.7% of predicted, p<0.01). In Group-1A versus 2A (RV<170 ml/m(2), with and without EDFF) this difference persisted, but in Group B there was no difference in VO2max-pred between patients with and without EDFF. The flow volume of EDFF correlated with VO2max-pred (r=0.444, p=0.007).

CONCLUSIONS

End-diastolic forward flow measured by magnetic resonance is present in patients with small and large RVs. The presence of EDFF is associated with better exercise tolerance, but only in patients with relatively small RVs.

Transesophageal Echocardiography in Tetralogy of Fallot

Transesophageal echocardiography (TEE) plays an important role in the anatomical, functional, and hemodynamic assessment of patients with congenital heart disease (CHD). This imaging approach has been applied to both children and adults with a wide range of cardiovascular malformations. Extensive clinical experience documents significant contributions, particularly in the perioperative setting. In fact, in the current medical era, many consider this technology to be an essential adjunct to surgical and anesthetic management in CHD. This review focuses on the applications of TEE in patients with tetralogy of Fallot (TOF), the most common form of cyanotic heart disease. Emphasis is given to the perioperative use of this imaging modality and benefits derived during the prebypass and postbypass periods. Limitations and pitfalls relevant to the TEE assessment in patients with this anomaly are also addressed.

Perioperative care of children with tetralogy of fallot

OPINION STATEMENT

Complete surgical repair of tetralogy of Fallot (TOF) around 3 months of age is the commonly undertaken management strategy in many centers and has excellent outcomes. Intervention at an earlier age, including the newborn period, may be required for children with symptoms. Early extubation from mechanical ventilation where possible may help improve outcomes for children undergoing complete repair of TOF.

Relation of right ventricular dilation, age of repair, and restrictive right ventricular physiology with patient-reported quality of life in adolescents and adults with repaired tetralogy of fallot

The present study aimed to determine the predictors of patient-reported quality of life and restrictive right ventricular (RV) physiology in adolescents and adults with repaired tetralogy of Fallot. A total of 62 patients (median age 28.5 years, range 14 to 69) undergoing cardiovascular magnetic resonance imaging completed the Short Form 36-item questionnaire, version 2, a validated quality of life assessment. RV inflow curves were generated from the sum of tricuspid inflow and pulmonary insufficiency. The patient-reported quality of life was comparable to population norms. Patients repaired after 1 year of age showed a strong trend toward a greater likelihood of physical component summary age-adjusted z-score ≤-1 (odds ratio 7.50, 95% confidence interval 0.90 to 62.3, p = 0.06). Patients with a RV ejection fraction of <45% reported decreased physical component summary (p = 0.02) and physical functioning (p = 0.02) scores. The RV end-diastolic volume, pulmonary regurgitation, and diastolic indexes did not predict the quality of life. The indexed RV end-diastolic volume was related to diastolic abnormalities, correlating with a greater peak early filling rate (r = 0.71, p <0.0001), ratio of peak early to atrial filling rates (r = 0.45, p = 0.006), and showing a strong trend with the end-diastolic forward flow in the pulmonary trunk (odds ratio 2.67 for moderate dilation and 3.50 for severe dilation, p = 0.06). Patients who underwent repair before 1 year old were more likely to have end-diastolic forward flow (15 of 17 vs 25 of 42, p = 0.03). In conclusion, the RV ejection fraction and age of repair were the best predictors of quality of life in this population, in whom end-diastolic forward flow and associated diastolic parameters appeared to reflect an overdistended ventricle, which might suggest a role for early pulmonary valve replacement.

Restrictive right ventricular physiology and right ventricular fibrosis as assessed by cardiac magnetic resonance and exercise capacity after biventricular repair of pulmonary atresia and intact ventricular septum

BACKGROUND

The hypertrophic myocardium, myocardial fiber disarray, and endocardial fibroelastosis in pulmonary atresia and intact ventricular septum (PAIVS) may provide anatomic substrates for restrictive filling of the right ventricle.

HYPOTHESIS

Restrictive right ventricle (RV) physiology is related to RV fibrosis and exercise capacity in patients after biventricular repair of PAIVS.

METHODS

A total of 27 patients, age 16.5 +/- 5.6 years, were recruited after biventricular repair of PAIVS. Restrictive RV physiology was defined by the presence of antegrade diastolic pulmonary flow and RV fibrosis assessed by late gadolinium enhancement (LGE) cardiac magnetic resonance. Their RV function was compared with that of 27 healthy controls and related to RV LGE score and exercise capacity.

RESULTS

Compared with controls, PAIVS patients had lower tricuspid annular systolic and early diastolic velocities, RV global longitudinal systolic strain, systolic strain rate, and early and late diastolic strain rates (all P < 0.05). A total of 22 (81%, 95% confidence interval: 62%-94%) PAIVS patients demonstrated restrictive RV physiology. Compared to those without restrictive RV physiology (n = 5), these 22 patients had lower RV global systolic strain, lower RV systolic and early diastolic strain rates, higher RV LGE score, and a greater percent of predicted maximum oxygen consumption (all P < 0.05).

CONCLUSION

Restrictive RV physiology reflects RV diastolic dysfunction and is associated with more severe RV fibrosis but better exercise capacity in patients after biventricular repair of PAIVS.

Tetralogy of Fallot

Tetralogy of Fallot is the most common form of cyanotic congenital heart disease, and one of the first to be successfully repaired by congenital heart surgeons. Since the first procedures in the 1950s, advances in the diagnosis, perioperative and surgical treatment, and postoperative care have been such that almost all those born with tetralogy of Fallot can now expect to survive to adulthood. The startling improvement in outcomes for babies born with congenital heart disease in general-and for those with tetralogy of Fallot in particular-is one of the success stories of modern medicine. Indeed, in many countries adults with tetralogy of Fallot outnumber children. Consequently, new issues have emerged, ranging from hitherto unpredicted medical complications to issues with training for caregivers and resource allocation for this population of survivors. Therefore, evolution of treatment, recognition of late complications, research on disease mechanisms and therapies-with feedback to changes in care of affected children born nowadays-are templates on which the timely discussion of organisation of care of those affected by congenital heart diseases from the fetus to the elderly can be based. Here, we focus on new developments in the understanding of the causes, diagnosis, early treatment, and late outcomes of tetralogy of Fallot, emphasising the continuum of multidisciplinary care that is necessary for best possible lifelong treatment of the 1% of the population born with congenital heart diseases.

Direction of preoperative ventricular shunting affects ventricular mechanics after Tetralogy of Fallot repair

BACKGROUND

Tetralogy of Fallot (TOF) typically results in clinical cyanosis or volume overload of the left ventricle (LV), depending on the direction and magnitude of shunting across the ventricular septal defect (VSD). The present study examines the effects of surgical TOF repair on LV mechanics and compares these changes between patients with VSD shunts that are predominantly right-to-left (R-L; "blue TOF") and those with VSD shunts that are predominantly left-to-right (L-R; "pink TOF").

METHODS AND RESULTS

Eleven patients (6 R-L and 5 L-R) 4.3 to 18.4 months old (median 7.1 months old) were studied. LV end-diastolic area (EDA) was calculated from transesophageal echocardiograms obtained during initiation and weaning of cardiopulmonary bypass. LV end-diastolic pressure was measured by micromanometer. Compliance was assessed by end-diastolic pressure-area curves. Contractility was assessed from preload recruitable stroke work by the stroke work-versus-LV EDA relation. VSD shunt direction was determined by preoperative Doppler echocardiography. Changes in LV function at the conclusion of cardiopulmonary bypass included decreased stroke area (from 6.6 +/- 0.9 to 4.1 +/- 0.4 cm(2)/m(2), P=0.012) and ejection fraction (from 55 +/- 2% to 41 +/- 3%, P<0.001). LV EDA at a common pressure in 8 patients decreased (from 10.4 +/- 1.4 to 7.6 +/- 1.2 cm(2)/m(2), P=0.003), which suggests a decrease in ventricular compliance. Additionally, the end-diastolic pressure-area curves shifted to the left in all patients. Preload recruitable stroke work decreased (from 34.8 +/- 2.4 to 21.8 +/- 2.6 mm Hg, P=0.007), which demonstrates a decrease in ventricular contractility. When separated by preoperative shunt direction, LV EDA increased in R-L patients by 0.9+/-0.5 cm(2)/m(2) postoperatively but decreased in L-R patients by 4.3 +/- 0.8 cm(2)/m(2) (P<0.001). Area ejection fraction decreased in all patients independent of shunting or change in LV EDA.

CONCLUSIONS

LV diastolic and systolic function are depressed after TOF repair. Mechanical effects of the VSD patch and myocardial depressant effects of ischemia and reperfusion during surgery probably contribute to the observed changes in LV mechanics. Different effects of surgical repair on LV preload in pink and blue TOF also contribute to the spectrum of clinical results observed after surgery.

In-utero intervention for severe congenital heart disease

The concept of fetal therapy is well established for many disorders diagnosed before birth but practical issues regarding its introduction into clinical practice are more difficult. Cardiac malformations are common, with major lesions affecting about 3.5 per thousand pregnancies; however, only a small proportion of these is likely to benefit from an intrauterine intervention. In addition, there are no good animal models of human cardiac disease and our knowledge of the underlying mechanisms is at best sketchy. This combination of factors has resulted in slow progress in developing effective therapies for the intrauterine management of cardiac disease. Recent research and clinical developments have included percutaneous valvuloplasty for severe aortic and pulmonary stenosis, perforation of the closed or restrictive inter-atrial septum and pacing for complete heart block. Progress in these endeavours has been variable but - overall - shows promise for treatment of the human fetus.

Diastolic Function in Repaired Tetralogy of Fallot at Rest and during Stress: Assessment with MR Imaging

PURPOSE

To prospectively assess, with magnetic resonance (MR) imaging, right ventricular (RV) diastolic function after repair of tetralogy of Fallot (TOF) at rest and during pharmacologic stress and to study relationship between main pulmonary artery end-diastolic forward flow (EDFF) (indicative of restrictive RV physiology) and clinical status.

MATERIALS AND METHODS

Institutional medical ethics committee approval and patient or parent informed consent were obtained. Patients with TOF corrected through the transatrial-transpulmonary approach underwent MR imaging at rest and during dobutamine stress and maximal exercise testing. Two-dimensional (2D) cine volumetric data were acquired. Flow measurements were performed with a standard 2D flow-sensitized sequence. MR imaging flow curves for tricuspid and pulmonary valves were combined into RV time-volume change curves, from which indexes of RV filling were derived. Patient results were compared with published data in control subjects. Student t tests, Mann-Whitney U tests, analysis of covariance, and paired and one-sample t tests were used.

RESULTS

Thirty-six patients (mean age at repair, 0.9 year +/- 0.5 [standard deviation]; median age at study inclusion, 17 years [range, 7-23 years]; 26 male and 10 female patients) were included. Abnormalities in RV filling included impaired relaxation (prolonged deceleration time, P = .002; smaller early filling fraction, P = .02) in the entire group compared with published data in healthy control subjects and signs of restriction to RV filling (smaller atrial filling fraction and higher early filling/atrial filling peak ratio, P < .05 for both) in patients with EDFF (n = 24) compared with patients without EDFF (n = 12). Stress response was abnormal in patients with EDFF, who developed impaired RV relaxation not appreciated at rest. Patients with EDFF had more severe pulmonary regurgitation (P < .05) and poorer exercise performance (P < .001).

CONCLUSION

In patients with TOF corrected with currently widely accepted surgical strategies, pulmonary artery EDFF relates to worse clinical state at mid- to long-term follow-up. Dobutamine stress imaging may unmask abnormalities in RV diastolic filling not appreciated with rest imaging alone.

The right ventricle in congenital heart disease

In patients with congenital heart disease the right ventricle (RV) may support the pulmonary (subpulmonary RV) or the systemic circulation (systemic RV). During the last 50 years evidence is accumulating that RV dysfunction develops in many of these patients and leads to considerable morbidity and mortality. Therefore RV function in certain groups of congenital heart disease patients needs close surveillance and timely and appropriate intervention to optimise outcomes. Despite major progress being made, assessing the RV either in the subpulmonary or the systemic circulation remains challenging, often requiring a multi-imaging approach and expertise (echocardiography, magnetic resonance imaging, nuclear and occasionally invasive assessment with angiography). This review discusses the implications of volume and pressure loading of the RV in the context of congenital heart disease and describes the most relevant imaging modalities for monitoring RV function.

Severe pulmonary regurgitation late after total repair of tetralogy of Fallot: surgical considerations

BACKGROUND

After total repair of tetralogy of Fallot (TOF-R) with transannular patching (TAP), severe pulmonary regurgitation (PR) is reported to develop in up to 30% of patients at a follow-up of 20 years, and 10-15% or more need pulmonary valve replacement (PVR). In this study, time-related progression of PR and right ventricular (RV) dilatation, and functional recovery of the RV after PVR are analyzed, and the possible causes of PR and timing of PVR are discussed.

METHODS

Eighteen patients, who late after TOF-R with TAP underwent PVR for severe PR, were chosen for the study. NYHA class, QRS duration, RV dilatation index (RVDI = RVEDD/LVEDD), and RV-distal pulmonary artery (PA) peak systolic gradient were reviewed and retrospectively analyzed.

RESULTS

TOF-R was performed at a mean age of 5.1 +/- 3.9 years (range: 0.6-12.8 years); the mean time interval from TOF-R to PR grade 3 onset was 11.8 +/- 7.0 years (range: 3.3-27.4 years), and from TOF-R to PVR was 18.5 +/- 7.8 years (range: 8.7-37.1 years). At PVR, 11 patients were in NYHA class II-III, all patients had severe PR (grade 3/3) and severe RV enlargement, 4 patients had ventricular arrhythmias, 7 patients significant distal pulmonary artery stenosis, and 2 patients small nonrelevant residual VSD. The mean preoperative RVDI (normal: 0.5) was 0.99 +/- 0.14 (range: 0.75-1.3), the mean QRS duration 170 +/- 24 ms (140-220 ms), and the mean RV-distal PA peak systolic pressure gradient 33.3 +/- 19.0 mmHg (range: 10-60 mmHg). Patients aged at TOF-R> 5 years had considerably longer redo-free intervals than their younger counterparts: mean 23.1 years (range 8.7-37.1 years) vs 14.8 years (range: 9.3-21.2 years), respectively. The redo-free intervals and the duration of severe PR correlated inversely with the RV-PA gradient. At a mean follow-up of 1.3 years (2 weeks-5 years), the mean RVDI decreased from 0.99 +/- 0.14 to 0.69 +/- 0.15, the mean validity class improved from 2.5 to 1.1. One patient died.

CONCLUSIONS

After TOF-R with TAP, the progression of PR has very individual dynamics, resulting in extremely varying redo-free intervals. Concomitant pulmonary stenosis seems to exaggerate progression of PR. PVR results in effective reduction of diastolic dimensions of severely dilated RV and in improvement of validity class. Referred PVR in no-risk cases seems to be justified.

How to start and sustain a successful pediatric cardiac intensive care program: A combined clinical and administrative strategy

OBJECTIVE: To delineate key clinical and administrative factors in starting a pediatric cardiac intensive care program and to introduce a scorecard concept to measure excellence in such a new program. Methods: Review of current clinical research data in pediatric cardiac intensive care and administrative business concepts for their application to the pediatric cardiac intensive care program. RESULTS: Although clinical concepts in cardiac intensive care are useful as basic philosophical strategies at the bedside, administrative principles are essential in operational strategies vital to the success of such a program. Using both clinical and business administrative concepts, a balanced strategy can be formulated. CONCLUSIONS: Starting a pediatric cardiac intensive care program is a difficult endeavor. A combined clinical and administrative approach is needed in starting and sustaining excellence in a pediatric cardiac intensive care program. Monitoring excellence in such a program warrants application of a scorecard system.