Mechanism and Risk Factors for Death in Adults With Tetralogy of Fallot

The impact of unilateral pulmonary artery stenosis on right ventricular to pulmonary arterial coupling in patients with transposition of the great arteries

BACKGROUND

Unilateral pulmonary artery (PA) stenosis is common in the transposition of the great arteries (TGA) after arterial switch operation (ASO) but the effects on the right ventricle (RV) remain unclear.

AIMS

To assess the effects of unilateral PA stenosis on RV afterload and function in pediatric patients with TGA-ASO.

METHODS

In this retrospective study, eight TGA patients with unilateral PA stenosis underwent heart catheterization and cardiac magnetic resonance (CMR) imaging. RV pressures, RV afterload (arterial elastance [Ea]), PA compliance, RV contractility (end-systolic elastance [Ees]), RV-to-PA (RV-PA) coupling (Ees/Ea), and RV diastolic stiffness (end-diastolic elastance [Eed]) were analyzed and compared to normal values from the literature.

RESULTS

In all TGA patients (mean age 12 ± 3 years), RV afterload (Ea) and RV pressures were increased whereas PA compliance was reduced. RV contractility (Ees) was decreased resulting in RV-PA uncoupling. RV diastolic stiffness (Eed) was increased. CMR-derived RV volumes, mass, and ejection fraction were preserved.

CONCLUSION

Unilateral PA stenosis results in an increased RV afterload in TGA patients after ASO. RV remodeling and function remain within normal limits when analyzed by CMR but RV pressure-volume loop analysis shows impaired RV diastolic stiffness and RV contractility leading to RV-PA uncoupling.

Staged therapeutic surgery for progressive pulmonary regurgitation and pacemaker induced cardiomyopathy after the tetralogy of fallot repair

BACKGROUND

Recently, improvements in the repair of tetralogy of Fallot have increased the need for reoperation in adulthood, and it's not rare that these reoperation candidates suffer from biventricular failure. However, there are no firm treatment guidelines, and each country, and even each facility, treats each case individually.

CASE PRESENTATION

We report the successful staged treatment of pulmonary regurgitation and pacemaker-induced cardiomyopathy with biventricular failure in adulthood in a case of complete atrioventricular block after tetralogy of Fallot repair in childhood. We planned a staged therapeutic strategy with preoperative left ventricular volume reduction with medication, following surgical pulmonary valve replacement concomitant epicardial lead implantation on the lateral basal wall, placed just beneath the generator pocket through 3rd intercostal space. in addition to postoperative intervention with a defibrillator to adjust cardiac resynchronization therapy, resulted in improvement of symptoms.

CONCLUSION

In a patient with biventricular failure after TOF repair, a staged treatment strategy involving medication, PVR, and CRT with a combination of epicardial and intravenous leads could be a useful treatment worth trying before heart transplantation.

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.

Temporal changes in the surgical management of patients with tetralogy of Fallot in Denmark: a nationwide cohort study

OBJECTIVES

To assess temporal changes in the surgical management of patients with tetralogy of Fallot including the timing of interventions, surgical techniques, reinterventions and survival in a nationwide cohort.

METHODS

Patients with tetralogy of Fallot in Denmark were divided into 3 eras based on their year of birth: early (1977-1991), intermediate (1992-2006) and late (2007-2021).

RESULTS

The cohort consisted of 745 patients. Median follow-up was 21.2 years (13.7-30.5). There was a temporal trend towards less shunt palliation (-0.3% per year, 95% CI -0.05 to -0.1). Median age at intracardiac repair was 2.9 years (1.8-5.0), 0.8 years (0.5-1.3) and 0.5 years (0.4-0.7) (P < 0.001) in the early, intermediate and late era, respectively. There was a temporal trend towards less valve-sparing repair (-0.7% per year, 95% CI -0.5 to -1.0) and more repair with transannular patches (0.7% per year, 95% CI 0.5-1.0). Survival at 10 years was 79% (64-76), 90% (87-93) and 95% (92-98) (P < 0.001) and pulmonary valve replacement within the first 10 years after intracardiac repair was performed in 3% (1-6), 12% (8-16) and 21% (13-29) (P < 0.001) in the early, intermediate and late era, respectively.

CONCLUSIONS

There was a temporal trend towards less shunt palliation and intracardiac repair at a younger age with more use of transannular patches. While survival throughout childhood and adolescence has improved, more patients undergo pulmonary valve replacement during the first 10 years after intracardiac repair.

Avalanches in cardiology

Sudden cardiac death (SCD) accounts for 15%–60% of mortality in patients with heart disease. Generally, this has been attributed to ventricular tachyarrhythmia. However, ventricular tachyarrhythmia has been documented or strongly suspected on clinical grounds in a relatively small proportion of SCD patients (8%–50%). Attempted prophylaxis of SCD by implantation of cardioverter-defibrillator is associated with variable success in different subsets of high-risk cardiac patients (30%–70%). A significant number of SCD, therefore, appear to be due to catastrophic circulatory failure. Multiple interdependent compensatory mechanisms help to maintain circulation in advanced cardiac disease. Rapid, unexpected, and massive breakdown of the compensated state can be precipitated by small and often imperceptible triggers. The initial critical but stable state followed by rapid circulatory failure and death has been considered to be analogous to snow avalanches. It is typically described in patients with left ventricular (LV) dysfunction (ischemic or nonischemic). It is now recognized that SCD can also happen in conditions where the right ventricle (RV) takes the brunt of the hemodynamic load. Advanced pulmonary arterial hypertension and operated patients of tetralogy of Fallot with pulmonary regurgitation are of particular interest to pediatric cardiologists. A large amount of data is available on LV changes and mechanics, while relatively little information is available on the mechanisms of RV adaptation to increased load and RV failure. Whether the triggers and the decompensatory processes are similar for the two ventricles is a moot point. This article highlights the currently available knowledge on the pathophysiology of SCD in RV overload states, with special reference to RV adaptive and decompensatory mechanisms, and therapeutic measures that can potentially interrupt the vicious downward course (cardiac avalanches).

What Is the Importance of Electrocardiography in the Routine Screening of Patients with Repaired Tetralogy of Fallot?

Background: In patients following complete repair of the tetralogy of Fallot, the duration of the QRS complex is associated with the size and mechanical function of the right ventricle, which are contemporarily assessed by cardiac magnetic resonance (CMR). Methods: 38 patients aged 18.0–54.9 years (median age 24.9 years) who had undergone complete repair of the tetralogy of Fallot were examined using CMR and concomitant 24 h ambulatory electrocardiography monitoring. We used statistical analysis to investigate the correlations between electrocardiographic parameters (heart rate, HR; PQ interval, PQ; QRS duration, QRS; and corrected QT interval, QTc) and CMR results (right ventricular ejection fraction, RVEF; right ventricular end-diastolic volume index, RVEDVI; and right ventricular end-systolic volume index, RVESVI) for patients after early and late repair. Results: The ECG-based parameters were not correlated with time since repair. There were significant correlations between QRS duration and RVEF (r = −0.61), RVEDVI (r = 0.56), and RVESVI (r = 0.54) for early operated patients but not for late-operated patients. No other substantial correlations were reported. Conclusion: Despite its role in screening for arrhythmias, electrocardiography has a limited role as a predictor of morphology and function of the right ventricle in patients after repair of the tetralogy of Fallot.

The role of cardiopulmonary exercise testing in predicting mortality and morbidity in people with congenital heart disease: a systematic review and meta-analysis

AIMS

The role of cardiopulmonary exercise testing (CPET) in predicting major adverse cardiovascular events (MACE) in people with congenital heart disease (ConHD) is unknown. A systematic review with meta-analysis was conducted to report the associations between CPET parameters and MACE in people with ConHD.

METHODS AND RESULTS

Electronic databases were systematically searched on 30 April 2020 for eligible publications. Two authors independently screened publications for inclusion, extracted study data, and performed risk of bias assessment. Primary meta-analysis pooled univariate hazard ratios across studies. A total of 34 studies (18 335 participants; 26.2 ± 10.1 years; 54% ± 16% male) were pooled into a meta-analysis. More than 20 different CPET prognostic factors were reported across 6 ConHD types. Of the 34 studies included in the meta-analysis, 10 (29%), 23 (68%), and 1 (3%) were judged as a low, medium, and high risk of bias, respectively. Primary univariate meta-analysis showed consistent evidence that improved peak and submaximal CPET measures are associated with a reduce risk of MACE. This association was supported by a secondary meta-analysis of multivariate estimates and individual studies that could not be numerically pooled.

CONCLUSION

Various maximal and submaximal CPET measures are prognostic of MACE across a variety of ConHD diagnoses. Further well-conducted prospective multicentre cohort studies are needed to confirm these findings.

Outcomes of adults with repaired tetralogy of Fallot from the national Scottish Cohort

BACKGROUND

The adult population of repaired tetralogy of Fallot is increasing and at risk of pre-mature death and arrhythmia. This study evaluates risk factors for adverse outcome and the effect of pulmonary valve replacement within a national cohort.

METHODS

A retrospective cohort study of 341 adult repaired tetralogy of Fallot (16-72 years) managed through a single national service was undertaken incorporating over 1200 patient-years of follow-up. Demographics, cardiopulmonary exercise testing, cardiac magnetic resonance, reintervention (including pulmonary valve replacement), and clinical events were analysed. The influence of these parameters on a primary outcome (death or arrhythmia) was evaluated.

RESULTS

Compared with an age-/gender-matched population, patients experienced a reduced survival, particularly males over 55 years (standardised mortality ratio : 6.12, 95% CI: 1.64-15.66, p = 0.004). Cox proportional hazards modelling identified increased indexed right ventricle (RV) end-diastolic volume (hazard ratio (HR): 2.86, 95% CI: 1.4-5.85, p = 0.004) and female gender (HR (male): 0.37, 95% CI: 0.14-0.98, p = 0.045) to be predictors significantly associated with the primary outcome. Pulmonary valve replacement undertaken at indexed RV end-diastolic volume = 145 ml/m2 reduced RV volumes and QRS duration but did not improve cardiopulmonary exercise testing nor NYHA class. Pulmonary valve replacement during cohort period was associated with increased risk of primary outcome (HR: 2.82, 95% CI: 1.36-5.86, p = 0.005).

CONCLUSIONS

Although the majority of adult tetralogy of Fallot were asymptomatic in NYHA 1, cardiopulmonary exercise testing revealed important deficits. Tetralogy of Fallot survival was reduced compared to the general population. Female gender and increasing RV end-diastolic volume predicted adverse events. Pulmonary valve replacement reduced RV volumes and QRS duration but did not improve primary outcome.

Prognostic Value of Preoperative Absolute Lymphocyte Count in Children With Tetralogy of Fallot

Background

Tetralogy of Fallot (TOF) is the most common cyanotic congenital heart disease. Absolute lymphocyte count (ALC) is a low‐cost and easy‐to‐obtain inflammatory indicator; however, its association with the prognosis of patients with TOF remains unknown. This study aimed to determine the prognostic value of preoperative ALC in children with TOF.

Methods and Results

This retrospective study included 707 patients aged <6 years who underwent corrective operations for TOF between January 2016 and December 2018 in Fuwai Hospital, China. The end points were mortality, extracorporeal membrane oxygenation placement, postoperative hospital stay >30 days, and severe postoperative complications; patients were grouped on the basis of prognosis: poor prognosis (n=76) and good prognosis (n=631). Univariable and multivariable logistic regression analyses were performed to identify the independent risk factors for poor prognosis, on which a risk scoring system was based. The receiver operating characteristic curve was used to assess model performance. Using another model without ALC, the effect of the addition of ALC was assessed. Results suggested that ALC was an independent factor with a cutoff point of 4.36×10⁹/L. The addition of ALC improved the area under the curve from 0.771 to 0.781 (P<0.001). To avoid reverse causality and further control for confounding factors, the patients were further divided on the basis of ALC level, and a propensity score matching was performed; 117 paired patients were identified for further analysis. Low ALC levels had an odds ratio of 3.500 (95% CI, 1.413–8.672).

Conclusions

Low preoperative ALC represents an independent predictor of poor prognosis in children with TOF.

[The adult with tetralogy of fallot: what the clinical cardiologist needs to know]

Tetralogy of Fallot (TOF) is the most common cyanotic congenital heart disease. After more than seven decades of the first palliative surgery, TOF prognosis has changed dramatically. The prevalence of TOF is approximately 3 per 10 000 births, representing 7 to 10% of congenital heart disease. With a higher survival into adulthood, the clinical cardiologist faces challenges in the management of this population, from severe pulmonary regurgitation to heart failure and ventricular arrhythmias. Its prevalence is approximately 3 per 10 000 live births, representing 7 to 10% of congenital heart disease. This review will describe the most relevant aspects of the care of adult patients with this disease.

Heart failure in adult congenital heart disease: tetralogy of Fallot

The number of rTOF patients who survive into adulthood is steadily rising, with currently more than 90% reaching the third decade of life. However, rTOF patients are not cured, but rather have a lifelong increased risk for cardiac and non-cardiac complications. Heart failure is recognized as a significant complication. Its occurrence is strongly associated with adverse outcome. Unfortunately, conventional concepts of heart failure may not be directly applicable in this patient group. This article presents a review of the current knowledge on HF in rTOF patients, including incidence and prevalence, the most common mechanisms of heart failure, i.e., valvular pathologies, shunt lesions, left atrial hypertension, primary left heart and right heart failure, arrhythmias, and coronary artery disease. In addition, we will review information regarding extracardiac complications, risk factors for the development of heart failure, clinical impact and prognosis, and assessment possibilities, particularly of the right ventricle, as well as management strategies. We explore potential future concepts that may stimulate further research into this field.

Peritoneal dialysis in an adult patient with tetralogy of Fallot diagnosed with incomplete Alagille syndrome

BACKGROUND

Alagille syndrome is an autosomal dominant disorder usually caused by pathogenic variants of the JAG1 gene. In the past, cholestasis was a condition sine qua non for diagnosis of the syndrome. However, recent advancements in genetic testing have revealed that clinical presentations vary from lack of symptoms, to multiorgan involvement. Tetralogy of Fallot, the most frequent complex congenital heart defect in Alagille Syndrome, very rarely leads to renal failure requiring dialysis - there are only single reports of such cases in the literature, with none of them in Alagille Syndrome.

CASE PRESENTATION

A 41-year-old woman suffering from cyanosis, dyspnea and plethora was admitted to the hospital. The patient suffered from chronic kidney disease and tetralogy of Fallot and had been treated palliatively with Blalock-Taussig shunts in the past; at admission, only minimal flow through the left shunt was preserved. These symptoms, together with impaired mental status and dysmorphic facial features, led to extensive clinical and genetic testing including whole exome sequencing. A previously unknown missense variant c.587G > A within the JAG1 gene was identified. As there were no signs of cholestasis, and subclinical liver involvement was only suggested by elevated alkaline phosphatase levels, the patient was diagnosed with incomplete Alagille Syndrome. End-stage renal disease required introduction of renal replacement therapy. Continuous ambulatory peritoneal dialysis was chosen and the patient's quality of life significantly increased. However, after refusal of further treatment, the patient died at the age of 45.

CONCLUSIONS

Tetralogy of Fallot should always urge clinicians to evaluate for Alagille Syndrome and offer patients early nephrological care. Although tetralogy of Fallot rarely leads to end-stage renal disease requiring dialysis, if treated palliatively and combined with renal dysplasia (typical of Alagille Syndrome), it can result in severe renal failure as in the presented case. There is no standard treatment for such cases, but based on our experience, peritoneal dialysis is worth consideration. Finally, clinical criteria for the diagnosis of Alagille Syndrome require revision. Previously, diagnosis was based on cholestasis - however, cardiovascular anomalies are found to be more prevalent. Furthermore, the criteria do not include renal impairment, which is also common.

Prognostic implications of inferior vena cava haemodynamics in ambulatory patients with tetralogy of Fallot

AIMS

Right atrial pressure (RAP) provides a composite measure of right ventricular diastolic dysfunction, right atrial compliance, and volume status, and these three variables are typically abnormal in adults with repaired tetralogy of Fallot (TOF). RAP is a well-established prognostic metric in patients with pulmonary hypertension, and recent data suggest that RAP is associated with clinical outcomes in TOF. The purpose of this study was to determine the role of inferior vena cava (IVC) haemodynamics (size and collapsibility) for the assessment of RAP and its potential application for risk stratification and prognostication in the TOF population.

METHODS AND RESULTS

Adult TOF patients with echocardiographic assessment of IVC haemodynamics were divided into patients with (derivation cohort, n = 256) and without (validation cohort, n = 492) cardiac catheterization data. We assessed the correlation between IVC haemodynamics, RAP, and disease severity indices [arrhythmias, peak oxygen consumption (VO₂ ), and heart failure hospitalization] in derivation cohort and compared it with the correlations in the validation cohort. IVC haemodynamics correlated with RAP (r = 0.52, P < 0.001), with disease severity indices {atrial arrhythmias [area under the curve (AUC) 0.81], ventricular arrhythmias [AUC 0.67], heart failure hospitalizations [AUC 0.78], and peak VO₂ [r = 0.53]}, and with transplant-free survival in the derivation cohort. Similar correlations between IVC haemodynamics, disease severity indices, and transplant-free survival were also observed in the validation cohort.

CONCLUSIONS

These findings suggest that IVC haemodynamics can potentially be used for risk stratification and prognostication in TOF patients and can complement the current risk models that are based predominately on right ventricular volumes and systolic function.

Impact of Inferior Venae Cava Assessment in Tetralogy of Fallot

Background

Inferior vena cava (IVC) size and collapsibility provide a noninvasive estimate of right heart filling pressures, an important determinant of right heart hemodynamic performance that is not measured by cardiac magnetic resonance imaging (CMRI). We hypothesized that compared with CMRI risk model alone, a combined CMRI-IVC risk model will have better correlation with disease severity and peak oxygen consumption in patients with tetralogy of Fallot (TOF).

Methods

We performed a retrospective review of patients with TOF with moderate/severe pulmonary regurgitation who underwent CMRI and echocardiography. A CMRI risk model was constructed using right ventricular (RV) end-diastolic volume index, RV end-systolic volume index, RV ejection fraction, and left ventricular ejection fraction. We added IVC hemodynamic classification to the CMRI indices to create CMRI-IVC risk model, and IVC hemodynamics were modeled as a categorical variable: normal vs mild/moderately abnormal (dilated IVC or reduced collapsibility) vs severely abnormal IVC hemodynamics (dilated IVC and reduced collapsibility). We defined disease severity as atrial arrhythmias, ventricular arrhythmias, and heart failure hospitalization.

Results

Of 207 patients, 131 (63%), 72 (35%), and 4 (2%) had normal, mild/moderately abnormal, and severely abnormal IVC hemodynamics, respectively. Compared with the CMRI risk model, the CMRI-IVC risk model had a better correlation with disease severity (area under the curve, 0.62; 95% confidence interval, 0.51-0.74 vs area under the curve 0.84, 95% confidence interval, 0.78-0.91, P = 0.006) and peak oxygen consumption (r = 0.35, P = 0.042 vs r = 0.43, P = 0.031, Meng test P = 0.026).

Conclusions

The combined CMRI-IVC risk model had a better correlation with disease severity compared with CMRI indices alone and can potentially improve risk stratification in the population with TOF.