Rationale and Design of the Canadian Outcomes Registry Late After Tetralogy of Fallot Repair: The CORRELATE Study

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

Objectives

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

Methods

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

Results

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

Conclusions

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

Electromechanical Dyssynchrony Is Associated With Right Ventricular Remodeling and Dysfunction Independently of Pulmonary Regurgitation Late After Tetralogy of Fallot Repair

BACKGROUND

The aim of this study was to investigate the relationship among right ventricular (RV) dilatation, dysfunction, and electromechanical dyssynchrony (EMD) in patients with repaired tetralogy of Fallot (rTOF).

METHODS

Data from a prospective rTOF registry of subjects with moderate or greater pulmonary regurgitation (PR) and contemporary imaging were analyzed. Electrocardiograms and echocardiograms were analyzed for EMD (prolonged QRS duration [QRSd], echocardiographic septal flash, and mechanical delay) and mechanical dispersion. The relationship among these, RV measurements on cardiac magnetic resonance, exercise capacity, and incident arrhythmia or death was analyzed with adjustment for PR.

RESULTS

In total, 271 patients with rTOF (42% women; median age, 32 years; interquartile range [IQR], 23-34 years) were included. Patients had moderate to severe PR (median PR fraction, 38%; IQR, 30%-47%), moderate to severe RV enlargement (median RV end-diastolic volume index, 161 mL/m2; IQR, 138-186 mL/m2) and mild RV systolic dysfunction (median RV ejection fraction [RVEF], 44%; IQR, 38%-48%). Eleven patients (4%) experienced ventricular arrhythmia or death. Presence of EMD was associated with larger RV size (RV end-diastolic volume index and RV end-systolic volume index, P = .006 and P < .001, respectively) and lower RVEF (P < .001). A sharp inflection in the relation among QRSd, RV size, and RVEF was observed when QRSd exceeded 150 msec (3.1% decrease in RVEF for every 20-msec increase in QRSd between 160 and 200 msec). Similar inflection points were observed for the mechanical delay between the RV basal-lateral and midseptal segments. The mechanical delay was higher in patients with vs without incident atrial arrhythmia (371 vs 276 msec, P = .014).

CONCLUSIONS

In adults with rTOF, EMD is independently associated with larger RV size, lower RVEF, and incident atrial arrhythmias.

Machine Learning for Prediction of Adverse Cardiovascular Events in Adults With Repaired Tetralogy of Fallot Using Clinical and Cardiovascular Magnetic Resonance Imaging Variables

BACKGROUND

Existing models for prediction of major adverse cardiovascular events (MACE) after repair of tetralogy of Fallot have been limited by modest predictive capacity and limited applicability to routine clinical practice. We hypothesized that an artificial intelligence model using an array of parameters would enhance 5-year MACE prediction in adults with repaired tetralogy of Fallot.

METHODS

A machine learning algorithm was applied to 2 nonoverlapping, institutional databases of adults with repaired tetralogy of Fallot: (1) for model development, a prospectively constructed clinical and cardiovascular magnetic resonance registry; (2) for model validation, a retrospective database comprised of variables extracted from the electronic health record. The MACE composite outcome included mortality, resuscitated sudden death, sustained ventricular tachycardia and heart failure. Analysis was restricted to individuals with MACE or followed ≥5 years. A random forest model was trained using machine learning (n=57 variables). Repeated random sub-sampling validation was sequentially applied to the development dataset followed by application to the validation dataset.

RESULTS

We identified 804 individuals (n=312 for development and n=492 for validation). Model prediction (area under the curve [95% CI]) for MACE in the validation dataset was strong (0.82 [0.74-0.89]) with superior performance to a conventional Cox multivariable model (0.63 [0.51-0.75]; P=0.003). Model performance did not change significantly with input restricted to the 10 strongest features (decreasing order of strength: right ventricular end-systolic volume indexed, right ventricular ejection fraction, age at cardiovascular magnetic resonance imaging, age at repair, absolute ventilatory anaerobic threshold, right ventricular end-diastolic volume indexed, ventilatory anaerobic threshold % predicted, peak aerobic capacity, left ventricular ejection fraction, and pulmonary regurgitation fraction; 0.81 [0.72-0.89]; P=0.232). Removing exercise parameters resulted in inferior model performance (0.75 [0.65-0.84]; P=0.002).

CONCLUSIONS

In this single-center study, a machine learning-based prediction model comprised of readily available clinical and cardiovascular magnetic resonance imaging variables performed well in an independent validation cohort. Further study will determine the value of this model for risk stratification in adults with repared tetralogy of Fallot.

Patient-Reported Outcomes After Tetralogy of Fallot Repair

BACKGROUND

Comprehensive assessment of tetralogy of Fallot (TOF) outcomes extends beyond morbidity and mortality to incorporate patient-reported outcomes (PROs), including quality of life (QOL) and health status (HS).

OBJECTIVES

This study explored PROs in adolescents and adults with TOF and delineated variables associated with PROs.

METHODS

This was a cross-sectional observational study within a larger prospective registry of adolescents and adults with repaired TOF and moderate or greater pulmonary regurgitation from North America, Europe, and Asia. Participants completed PROs, including a QOL linear analogue scale (QOL-LAS) and an HS visual analogue scale (HS-VAS). Scores were classified according to age cohorts: <18, 18 to 25, 26 to 40, and >40 years.

RESULTS

The study included 607 patients (46.3% female; median age 28.5 years). Median QOL-LAS scores (0-100) were similar across age cohorts (85, 80, 80, 80; P = 0.056). Median HS-VAS scores (0-100) were lowest for the oldest cohort (77) compared with the 3 younger cohorts (85, 80, 80) (P = 0.004). With advancing age, there were increased reports of poor mobility (P < 0.001) and pain or discomfort (P = 0.004); problems in these dimensions were reported by 19.1% and 37.2% of patients aged >40 years, respectively. Of factors associated with superior PROs on multivariable regression modeling (ie, being White, being nonsyndromic, having employment, and having better left ventricular function; P < 0.05), asymptomatic status (functional class I) was the variable associated with the greatest number of QOL and HS measures (P < 0.001).

CONCLUSIONS

Strategies to improve TOF outcomes should consider PROs alongside conventional clinical variables. Factors associated with poorer PROs represent opportunities to intervene to improve the lives of patients with TOF.

Arrhythmias in repaired pediatric and adolescent Fallot tetralogy, correlation with cardiac MRI parameters

Background

Tetralogy of Fallot (TOF) is a common congenital cyanotic heart disease in which arrhythmias could develop even after successful operative repair. Pulmonary regurgitation and right ventricular dilatation develop in many cases. The relation between arrhythmias and right ventricular dilatation is not established. Our aim is to assess the relation in between the degree of right ventricular volume affection and the severity of the pulmonary regurgitation, associated arrhythmias and the need for pulmonary valve repair in Egyptian pediatric and adolescent cases after successful TOF repair.

Results

A cross sectional descriptive study was conducted on 32 cases after successful surgical repair. Transthoracic Doppler echocardiography, 24 h Holter monitoring and cardiac MRI for assessment of pulmonary regurgitation fraction (PRF), ventricular volumes and function were measured. Cases were classified according to right ventricular end diastolic volume index (RVEDVI) into 2 groups with cut off value 150 ml/m2. Mean age of the studied cases was (12.96 ± 3.384) years, mean age at time of surgical repair was (34.23 ± 22.1) months, and mean duration postoperatively was (121.72 ± 41.028) months. Eighteen cases (56%) had RVEDVI ≥ 150 ml/m2, PRF was significantly higher in cases with increased RVEDVI (p value 0.007), with positive significant correlation between RVEDVI and PRF (p value = 0.0001, r = 0.61). Arrhythmias were detected in 18 cases (56%), the most common of which was infrequent supraventricular ectopy. No significant difference in incidence of arrhythmias between the 2 groups (p value = 1) with also no significant correlation between arrhythmias and increased RVEDVI (p value = 0.76, r = 0.05). No difference between cases with and without arrhythmias regarding RVEDVI (p value = 0.56) or PRF (p value = 0.5).

Conclusion

Holter detected arrhythmias after successful surgical repair of TOF were significantly associated with increased postoperative duration but not with PRF or RVEDVI.

National and regional registries for congenital heart diseases: Strengths, weaknesses and opportunities

BACKGROUND

We aim to establish a new and informative bi-national Registry for Congenital Heart Disease (CHD) patients in Australia and New Zealand, to document the burden of disease and clinical outcomes for patients with CHDs across the lifespan. When planning for the implementation of this Registry, we sought to evaluate the strengths and weaknesses of existing national and large regional CHD databases.

METHODS

We characterised 15 large multi-institutional databases of pediatric and/or adult patients with CHD, documenting the richness of their datasets, the ease of linkage to other databases, the coverage of the target cohort and the strategies utilised for quality control.

RESULTS

The best databases contained demographic, clinical, physical, laboratory and patient-reported data, and were linked at least to the national/regional death registry. They also employed automatic data verification and regular manual audits. Coverage ranged from around 25% of all eligible CHD cases for larger databases to near 100% for some smaller registries of patients with specific CHD lesions, such as the Australia and New Zealand Fontan Registry.

CONCLUSIONS

Existing national and regional CHD databases have strengths and weaknesses; few combine complete coverage with high quality and regularly audited data, across the broad range of CHDs.

How pulmonary valve regurgitation after tetralogy of fallot repair changes the flow dynamics in the right ventricle: An in vitro study

Tetralogy of Fallot is the most common cyanotic congenital disease, affecting 10% of children with congenital heart disease. The surgical management of patients with Tetralogy of Fallot leads, however, to significant detrimental effects on the right ventricle including pulmonary valve regurgitation. This experiment aimed to simulate different cases of pulmonary valve regurgitation with varying degrees of severity in order to observe the changes in flow structures present in the right ventricle. Planar time-resolved particle image velocimetry measurements have been performed on a custom-made double activation simulator reproducing flow conditions in a model of a right ventricle. Changes in flow characteristics in the right ventricle have been evaluated in terms of velocity fields and profiles, tricuspid inflow jet orientation and viscous energy dissipation. Our results show that pulmonary valve regurgitation significantly alters the flow in the right ventricle mostly by impairing the diastolic inflow through the tricuspid valve and by increasing viscous energy loss. This fundamental work should allow for a better understanding of such changes in the RV flow dynamics. It may also help in developing new strategies allowing for a better follow-up of patients with repaired TOF and for decision-making in terms of pulmonary valve replacement.

Characteristics of Cardiovascular Magnetic Resonance Imaging and Outcomes in Adults With Repaired Truncus Arteriosus

The cardiovascular magnetic resonance imaging (CMR) features of adults with repaired truncus arteriosus (rTA) are largely undefined. We sought to explore CMR characteristics in rTA and to identify associations between imaging findings and cardiovascular outcomes. Adults with rTA and CMR were identified and anatomic subtypes (1-4) were assigned (Collett and Edwards classification). CMR characteristics, clinical data at last follow-up and adverse cardiovascular outcome were recorded. Twenty-seven adults (19% male) were studied (median age at cardiovascular magnetic resonance 26 years [interquartile range 18 to 40]) over 5.2-year duration [interquartile range 2.5 to 7.5]. With the exception of mildly increased RV mass (30 ± 12 g/m²), cardiac chamber measurements were within the normal range. In CMR measurements, only pulmonary artery peak velocity differed in subtypes (highest in subtype 3, 318 ± 26 cm/s, p = 0.029). Number of cardiovascular interventions in adulthood was moderately correlated with left ventricular end-diastolic volume (r = 0.463, p = 0.015), left ventricular ejection fraction (r = 0.425, p = 0.027) and neoaortic root size (r = 0.398, p = 0.039). Cardiovascular events (nonmutually exclusive) in 5 of 27 patients (19%) included death (n = 1), heart failure (n = 1), ventricular tachycardia (n = 1), and atrial tachycardia (n = 3). Increased cardiovascular risk was associated with decreased right ventricular ejection fraction (odds ratio 1.153, confidence interval 1.003 to 1.326, p = 0.046) and smaller ascending aorta diameter (odds ratio 1.758, confidence interval 1.037 to 2.976, p = 0.036). In conclusion, decreased right ventricular ejection fraction and smaller ascending aorta on cardiovascular magnetic resonance were associated with adverse events in rTA.

Right ventricular fibrosis is associated with cardiac remodelling after pulmonary valve replacement

Objective

The relationship between right ventricular (RV) fibrosis and right heart reverse remodelling following pulmonary valve replacement (PVR) has not been well studied in adults with repaired tetralogy of Fallot (rTOF). Our aims were to histologically quantify RV fibrosis and to explore the relationship between fibrosis severity and cardiac remodelling post-PVR.

Methods

Adults with rTOF and pre-PVR cardiovascular (CMR) imaging were consented to procurement of RV muscle during PVR. Samples were stained with picrosirius red to quantify collagen volume fraction. Clinical data at baseline and at last follow-up were reviewed. Adverse cardiovascular outcomes included death, sustained arrhythmia and heart failure.

Results

Fifty-three patients (male 58%, 38±11 years) were studied. Those with severe fibrosis (collagen volume fraction >11.0%, n=13) had longer aortic cross-clamp times at initial repair compared with the remainder of the population (50 vs 33 min, p=0.018) and increased RV mass:volume ratio pre-PVR (0.20 vs 0.18 g/mL, p=0.028). Post-PVR, the severe fibrosis group had increased indexed RV end-systolic volume index (RVESVi) (74 vs 66 mL/m2, p=0.044), decreased RVESVi change (Δ29 vs Δ45 mL/m2, p=0.005), increased RV mass (34 vs 25 g/m2, p=0.023) and larger right atrial (RA) area (21 vs 17 cm2, p=0.021). A trend towards increased heart failure events was observed in the severe fibrosis group (15% vs 0%, p=0.057).

Conclusions

Severe RV fibrosis was associated with increased RVESVi, RV mass and RA area post-PVR in rTOF. Further study is required to define the impact of fibrosis and persistent right heart enlargement on clinical outcomes.

Surgery for Tetralogy of Fallot in Adults: Early Outcomes

Objective

To study the in-hospital outcome of adult patients who had undergone surgical repair for Tetralogy of Fallot.

Methods

A retrospective descriptive study was conducted at the Punjab Institute of Cardiology searching the hospital records. All those adult patients who had undergone repair for Tetralogy of Fallot from January 2012 to December 2014 were included in the study. All the patients were operated by the same surgical team. Patients who underwent primary repair as well as those with previous palliative procedures were included in the study. Thirty days outcome was studied by recording variables from the database. Data was analysed using Statistical Package for Social Sciences version 16.

Results

A total of 80 patients was included in the study, in which there were 48 (60%) male patients and 32 (40%) female patients. Mean age was 21±0.21 years. Those with previous palliation were 15 (18.75%). The associated problems observed were: atrial septal defect 27 (33.75%), right aortic arch 30 (37.5%), patent ductus arteriosus 6 (7.5%) and double outlet right ventricle 3 (3.75%). In-hospital mortality recorded was 7 (8%). Postoperative complications encountered were low cardiac output syndrome 9 (11.25%), pleural effusion requiring tapping 3 (3.75%), reoperation for bleeding 3 (3.8%), pulmonary regurgitation (moderate to severe) 20 (25%) which occurred in the transannular patch group only and atrial arrhythmia 4 (5%).

Conclusion

A large number of adult patients are still operated for tetralogy of Fallot in Pakistan. With increasing experience in the technique the mortality and morbidity is comparable to international literature.

Tetralogy of Fallot repair in patients presenting after Infancy: A single surgeon experience

Objective:

To determine the early surgical outcomes of Tetralogy of Fallot (TOF) repair in children and young adults operated after the age of one year.

Methods:

In this retrospective study, 307 cases of primary repair of Tetralogy of Fallot were done between September 2012 to February 2017, at CPE Institute of cardiology, Multan. Out of 307 operated patients, 4 (1.3%) patients had previous modified Blalock Taussig shunts, 2 (0.6%) associated ASD with TOF, 3 (0.9%) co-association of TOF with PDA, 2 (0.6%) had large conal arterial branch crossing the annulus, 3 (0.9%) had dextrocardia with situs inversus, 12 (3.9%) TOF with double outlet right ventricle (DORV), 2 (0.6%) were associated with complete AV canal defect, 8 (2.60%) with absent pulmonary valve syndrome, 15 (5.5%) with left pulmonary artery stenosis. Data of post-operative complications and operative parameters was recorded for all patients.

Results:

Mean age of operated patients was 9.56±4.89 years. Post-operative complications occurred in 7.8% of patients. Most common post-operative complications were pleural effusion with a frequency of 12(3.9%) patients, and complete heart block in one patient. Insignificant small residual VSD was diagnosed in 8 (2.6%) patients. One moderately large VSD was closed surgically after one year of 1^st surgery. Moderate to severe pulmonary valve regurgitation was diagnosed in 114 (37.1%) patients. Mild to moderate tricuspid regurgitation in 15 (4.8%) patients and moderate right ventricular outflow tract obstruction (RVOT) in 16 (5.2%) patients. Thirty-day mortality was only four (1.3%).

Conclusion:

Surgical correction of Tetralogy of Fallot (TOF) in children after one year carries good operative outcomes with minimum morbidity and mortality.

The Role of Cardiopulmonary Exercise Testing for Decision Making in Patients with Repaired Tetralogy of Fallot

Tetralogy of Fallot is the most common form of cyanotic congenital heart disease. As a result of the surgical strategies employed at the time of initial repair, chronic pulmonary regurgitation (PR) is prevalent in this population. Despite sustained research efforts, patient selection and timing of pulmonary valve replacement (PVR) to address PR in young asymptomatic patients with repaired tetralogy of Fallot (rToF) remain a fundamental but as yet unanswered question in the field of congenital heart disease. The ability of the heart to compensate for the chronic volume overload imposed by PR is critical in the evaluation of the risks and benefits of PVR. The difficulty in clarifying the functional impact of PR on the cardiovascular capacity may be in part responsible for the uncertainty surrounding the timing of PVR. Cardiopulmonary exercise testing (CPET) may be used to assess abnormal cardiovascular response to increased physiologic demands. However, its use as a tool for risk stratification in asymptomatic adolescents and young adults with rToF is still ill-defined. In this paper, we review the role of CPET as a potentially valuable adjunct to current risk stratification strategies with a focus on asymptomatic rToF adolescents and young adults being considered for PVR. The role of maximal and submaximal exercise measurements to identify young patients with a decreased or borderline low peak VO₂ resulting from impaired ventricular function is explored. Current knowledge gaps and research perspectives are highlighted.

Pulmonary Valve Procedures Late After Repair of Tetralogy of Fallot: Current Perspectives and Contemporary Approaches to Management

Few topics in adult congenital heart disease have approached the level of scrutiny bestowed on pulmonary valve replacement (PVR) strategies late after tetralogy of Fallot (TOF) repair. Despite the successes of primary surgery for TOF, there is a growing group of adults with residual right ventricular outflow tract and pulmonary valve dysfunction. Patients with residual chronic pulmonic regurgitation as a consequence of earlier surgery can later develop symptoms of exercise intolerance and complications including heart failure, tachyarrhythmias, and sudden cardiac death. Optimal timing of PVR has sparked debate, which has catalyzed increasing research efforts over the past decade. Although performance of PVR in the absence of symptoms is currently on the basis of the rationale that achievement of complete reverse remodelling is highly desirable, whether this approach results in improvement in patient outcomes in the long-term has yet to be shown. Surgical PVR and percutaneous pulmonary valve intervention are different techniques with specific advantages and disadvantages that require careful consideration for each individual patient, alongside the need for requisite reinterventions over the course of a patient's lifetime. Criteria pertaining to referral strategies are ever being refined as newer technologies for percutaneous therapies continue to evolve. In this article we review the literature surrounding the indications for, the optimal timing of, and the approaches to pulmonary valve procedures in adults with previously repaired TOF.

Clinical Databases and Registries in Congenital and Pediatric Cardiac Surgery, Cardiology, Critical Care, and Anesthesiology Worldwide

The growth in large-scale data management capabilities and the successful care of patients with congenital heart defects have coincidentally paralleled each other for the last three decades, and participation in multicenter congenital heart disease databases and registries is now a fundamental component of cardiac care. This manuscript attempts for the first time to consolidate in one location all of the relevant databases worldwide, including target populations, specialties, Web sites, and participation information. Since at least 1,992 cardiac surgeons and cardiologists began leveraging this burgeoning technology to create multi-institutional data collections addressing a variety of specialties within this field. Pediatric heart diseases are particularly well suited to this methodology because each individual care location has access to only a relatively limited number of diagnoses and procedures in any given calendar year. Combining multiple institutions data therefore allows for a far more accurate contemporaneous assessment of treatment modalities and adverse outcomes. Additionally, the data can be used to develop outcome benchmarks by which individual institutions can measure their progress against the field as a whole and focus quality improvement efforts in a more directed fashion, and there is increasing utilization combining clinical research efforts within existing data structures. Efforts are ongoing to support better collaboration and integration across data sets, to improve efficiency, further the utility of the data collection infrastructure and information collected, and to enhance return on investment for participating institutions.

A first population-based long-term outcome study in adults with repaired tetralogy of Fallot in Malta

OBJECTIVES

To determine overall and reintervention-free survival for repaired Maltese tetralogy of Fallot patients and to investigate the potential impact of gender, age at repair, genetic syndromes, previous palliation, and type of repair on these outcomes.

DESIGN

All 130 tetralogy of Fallot patients born before the end of 1997 included in the local database were extracted. Surgical repair type, age at repair and operative survival were analyzed among the 103/130 repaired patients. Kaplan-Meier survival analyses were performed on the 75 repair survivors with complete follow-up data (mean follow-up 26.37 ± 9.27 (range 9.95-51.21) years).

RESULTS

Patients born after 1985 were operated at a younger age (median 1.28 years) compared with patients born before 1985 (median 9.64 years) (P < .001). Transannular patch repair was the commonest operation among patients born after 1985 (43.90%), while repair without transannular patch use prevailed among those born before 1985 (66.13%). 90.24% of patients born after 1985 survived reparative surgery compared with 70.37% of those born before 1985. Of the 75 repair survivors, 7 (9.33%) died of cardiac causes and 22 (29.33%) needed reintervention during follow-up. Overall estimated mean survival was 45.56 years (95% CI 41.67-49.24) with estimated survival rate of 77.5% at 40 years from repair. Estimated mean reintervention-free survival was 37.71 years (95% CI 33.75-41.66) with estimated reintervention-free survival rate of 59.2% at 40 years. Patients with genetic syndromes had significantly lower overall survival after repair. Transannular patch repair was associated with significantly lower reintervention-free survival (median 32.37 years (95% CI 12.75-51.99)) compared with repair without transannular patch [median 44.21 years (95% CI 43.06-45.35); P = .03].

CONCLUSIONS

Although survival after tetralogy of Fallot repair in contemporary patients is very good, cardiac death can occur at any stage and structural reintervention is common. Regular follow-up with imaging and rhythm monitoring remains of utmost importance in all patients.

Differential Impact of Pulmonary Regurgitation on Patients With Surgically Repaired Pulmonary Stenosis Versus Tetralogy of Fallot

Patients with repaired pulmonary stenosis (PS) or tetralogy of Fallot (TOF) both develop pulmonary regurgitation (PR) leading to right ventricular (RV) dilatation and dysfunction. We aimed to characterize differential effects of chronic PR in these populations. Patients with surgically repaired PS were matched 1:2 by age and PR fraction with patients with TOF. Patients with previous pulmonary valve replacement were excluded. Cardiovascular magnetic resonance data were compared; peak longitudinal and circumferential systolic strain by feature tracking were compared to evaluate differential contribution of the RV sinus and outflow tract, respectively. PS (n = 24, 41 ± 13 years old) and TOF (n = 47, 39 ± 13 years old) patients did not differ in RV end-diastolic volume (153 ± 45 vs 154 ± 45 ml/m(2), p = 0.99) or diastolic function. However, patients with PS had preserved RV ejection fraction (54.3 ± 4.4% vs 48.0 ± 7.1%, p <0.0001). Differences were greater in RV circumferential (-15.8 ± 3.3 vs -11.8 ± 3.4, p <0.0001) than longitudinal strain (-18.0 ± 3.8 vs -15.9 ± 3.8, p = 0.04), with particular decrease in the infundibulum (-17.4 ± 7.5 vs -6.8 ± 6.3, p <0.0001). Late gadolinium enhancement in the RV outflow tract was more frequent in patients with TOF (70.2% vs 45.8%, p = 0.001). In conclusion, surgical repair of PS leads to similar RV dilatation and diastolic dysfunction compared to patients with TOF, but differential effects on ventricular systolic function, largely related to differences in the outflow tract. With different patterns of scarring and ventricular remodeling, further study is needed to clarify whether criteria for pulmonary valve replacement in patients with PS should differ from those with TOF.

NT-proBNP Indicates Left Ventricular Impairment and Adverse Clinical Outcome in Patients With Tetralogy of Fallot and Pulmonary Regurgitation

BACKGROUND

The goal of this study was to interrelate N-terminal B-type natriuretic peptide (NT-proBNP) levels and cardiac magnetic resonance imaging-derived ventricular function, mass, and volumes in adults with pulmonary regurgitation after Fallot repair and to evaluate the prognostic relevance of these parameters regarding adverse clinical outcome.

METHODS

Eighty-one patients (aged 26.3 ± 7.4 years; male sex, 45.7%; New York Heart Association class I, 72.8%; pulmonary valve velocity, < 3 m/s) were included. At baseline cardiac magnetic resonance imaging and NT-proBNP measurements were performed.

RESULTS

During a mean observation time of 6.9 ± 2.6 years, 13 patients (16.1%) had sustained supraventricular arrhythmias or heart failure (2.4 per 100 patient-years). Multivariate Cox analysis identified NT-proBNP, left ventricular (LV) end-systolic volume index and LV ejection fraction, right ventricular (RV) end-diastolic volume index, and tricuspid regurgitation as independent predictors of adverse events. NT-proBNP correlated with LV but not with RV parameters. In receiver operating characteristic curve analysis using significant variables of the multivariate analysis, NT-proBNP was superior to all other parameters to detect patients at risk (area under the curve [AUC], 0.873; 95% confidence interval, 0.772-0.974). LV end-systolic volume index (AUC, 0.734), RV end-diastolic volume index (AUC, 0.645) und tricuspid regurgitation (AUC, 0.747) showed lower diagnostic accuracy.

CONCLUSIONS

Even in mildly symptomatic patients with pulmonary regurgitation after Fallot repair NT-proBNP is a strong predictor of adverse outcome. It is rather associated with LV but not with RV impairment. In severe pulmonary regurgitation an increase in the level of NT-proBNP and LV impairment seem to provide additional useful information for the timing of pulmonary valve replacement.