Factors associated with mortality or transplantation versus Fontan completion after cavopulmonary shunt for patients with tricuspid atresia.

OBJECTIVE: Tricuspid atresia with normally related great vessels (TA) is considered the optimal substrate for the Fontan pathway. The factors associated with death or transplantation after cavopulmonary shunt (CPS) are underappreciated. We aimed to determine factors associated with CPS-Fontan interstage death/transplantation versus transition to Fontan in TA. METHODS: A total of 417 infants younger than 3 months of age with TA were enrolled (January 1999 to February 2020) from 40 institutions into the Congenital Heart Surgeons' Society TA cohort. Parametric competing risk methodology was used to determine factors associated with the competing end points of death/transplantation without Fontan completion, and transition to Fontan. RESULTS: CPS was performed in 382 patients with TA; of those, 5% died or underwent transplantation without transition to Fontan and 91% transitioned to Fontan by 5 years after CPS. Prenatal diagnosis (hazard ratio [HR], 0.74; P < .001) and pulmonary artery band (PAB) at CPS (HR, 0.50; P < .001) were negatively associated with Fontan completion. Preoperative moderate or greater mitral valve regurgitation (HR, 3.0; P < .001), concomitant mitral valve repair (HR, 11.0; P < .001), PAB at CPS (HR, 3.0; P < .001), postoperative superior vena cava interventions (HR, 9.0; P < .001), and CPS takedown (HR, 40.0; P < .001) were associated with death/transplantation. CONCLUSIONS: The mortality rate after CPS in patients with TA is notable. Those with preoperative mitral valve regurgitation remain a high-risk group. PAB at the time of CPS being associated with both increased risk of death and decreased Fontan completion may represent a deleterious effect of antegrade pulmonary blood flow in the CPS circulation.

Major aortopulmonary collateral arteries in a case of unrepaired tricuspid and pulmonary atresia with single ventricle physiology.

Tricuspid and pulmonary atresia with single ventricle physiology and major aortopulmonary collateral arteries (MAPCAs) is a complex cyanotic congenital heart disease with heterogeneous pulmonary artery morphology and arborization. The complex anatomy and physiology, coupled with a dearth of existing literature, pose imitable challenges to treatment. Although the exact surgical algorithm is still unclear, the goal is a well-developed, low-resistance pulmonary vascular bed. A precise understanding of the blood supply to each lung is a requisite for successful surgery, and a multimodality and multidisciplinary approach is compulsory. Herein, we describe a case of tricuspid and pulmonary atresia with single ventricle, MAPCAs and aortopulmonary collateral arteries.

Identification and analysis of KLF13 variants in patients with congenital heart disease.

BACKGROUND: The protein Kruppel-like factor 13 (KLF13) is a member of the KLF family and has been identified as a cardiac transcription factor that is involved in heart development. However, the relationship between KLF13 variants and CHDs in humans remains largely unknown. The present study aimed to screen the KLF13 variants in CHD patients and genetically analyze the functions of these variants. METHODS: KLF13 variants were sequenced in a cohort of 309 CHD patients and population-matched healthy controls (n = 200) using targeted sequencing. To investigate the effect of variants on the functional properties of the KLF13 protein, the expression and subcellular localization of the protein, as well as the transcriptional activities of downstream genes and physical interactions with other transcription factors, were assessed. RESULTS: Two heterozygous variants, c.487C > T (P163S) and c.467G > A (S156N), were identified in two out of 309 CHD patients with tricuspid valve atresia and transposition of the great arteries, respectively. No variants were found among healthy controls. The variant c.467G > A (S156N) had increased protein expression and enhanced functionality compared with the wild type, without affecting the subcellular localization. The other variant, c.487C > T (P163S), did not show any abnormalities in protein expression or subcellular localization; however, it inhibited the transcriptional activities of downstream target genes and physically interacted with TBX5, another cardiac transcription factor. CONCLUSION: Our results show that the S156N and P163S variants may affect the transcriptional function of KLF13 and physical interaction with TBX5. These results identified KLF13 as a potential genetic risk factor for congenital heart disease.

Bosentan Therapy in a Patient with Failed Fontan Procedure: A Case Report.

BACKGROUND: Increased pulmonary vascular resistance index (PVR) leads to several complications in patients after a Fontan operation. This increase is mainly attributed to the overexpression of endothelin-1 for a long duration after the Fontan procedure. Here, we describe the case of a 3-year-old boy with a failed Fontan operation who was treated with bosentan, an endothelin-1 receptor blocker. CASE REPORT: Cardiac catheterization was performed, which showed a main pulmonary artery pressure (MPAP) of 19 mmHg and PVRI of 5.6 woods/m2. Oral bosentan regimen at a dose of 31.25 mg was initiated twice a day. The treatment was continued as pleural effusion and ascites persisted. No adverse events were observed, and the treatment was well tolerated. Pleural effusion disappeared, and ascites decreased markedly after 4 weeks, whereas the MPAP was 15 mmHg and the PVRI was 4.3 woods/m2. After 3 months of bosentan therapy, the MPAP was 12 mmHg and the PVRI was 4.1 woods/m2. CONCLUSION: We observed that bosentan reduces the PVRI and complications such as pleural effusion and ascites after a failed Fontan procedure.

Evaluation of the anatomic and hemodynamic abnormalities in tricuspid atresia before and after surgery using computational fluid dynamics.

Analysis of hemodynamics inside tricuspid atresia (TA) chamber is essential to the understanding of TA for optimal treatment. In this study, we introduced a combined computational fluid dynamics (CFD) to simulate blood flow in the left ventricle (LV) to study the diastolic flow changes in TA.Real-time 3-dimentional echocardiography loops (ECHO) were acquired in normal control group, in TA patients before surgery (pre-op group) and after surgery (post-op group). ECHO loops were reconstructed and simulated by CFD, the geometric, volumetric changes, and vortices in the LV were studies and compare among 3 groups.Compared with the control group, pre-op TA patients demonstrated significant LV remodeling, manifesting with smaller LV length, larger diameter, width and spherical index, as well as lager volumes; post-op TA group showed revisions in values of both geometric and volumetric measurements. CDF also demonstrated the abnormality of vortices in the pre-op TA patients and the alteration of existence and measurements of vortex in postoperation group.Echo-based CFD modeling can show the abnormality of TA in both LV geometric, volumetric measurements and intracardiac vortices; and CFD is capable to demonstrate the alterations of LV after Fontan and Glenn surgical procedure.

Relation of Increased Epicardial Fat After Fontan Palliation to Cardiac Output and Systemic Ventricular Ejection Fraction.

Epicardial fat produces multiple proinflammatory cytokines and is associated with adverse cardiovascular events. Inflammation and resultant endothelial dysfunction may play a role in progressive myocardial dysfunction among adults with single ventricle physiology after Fontan palliation, but the potential impact of increased epicardial fat volume (EFV) has not been studied. This study sought to determine if there is greater EFV in Fontan patients compared with a group of repaired tetralogy of Fallot (rTOF) patients. We retrospectively measured EFV manually on cardiac magnetic resonance imaging in Fontan patients, ≥15 years, and 1:1 age, sex, and body mass index-matched patients with rTOF. EFV was indexed to body surface area. A random subset of studies was re-measured to assess intra- and interobserver reliability. Fontan patients (n = 63, median age 21.6 years, 51% male, mean body mass index 24.2 ± 5.6 kg/m2) had a larger indexed EFV compared with matched rTOF patients (75.3 ± 29.2 ml/m2 vs 60.0 ± 19.9 ml/m2, p = 0.001). In Fontan patients, indexed EFV was inversely correlated with ventricular ejection fraction (r = -0.26, p = 0.04) and cardiac index (r = -0.33, p = 0.01). Intra- and interobserver reliabilities of the indexed EFV measurements in both groups were excellent (intraclass correlation coefficient ranges from 0.93 to 0.97). In conclusion, indexed EFV is higher in Fontan patients compared with patients with rTOF and is associated with lower ventricular ejection fraction and cardiac index. Increased EFV could play a role in the failing Fontan circulation, but longitudinal studies are necessary to establish any causative role.

Pediatric Fontan patients are at risk for myocardial fibrotic remodeling and dysfunction.

BACKGROUND: Patients with single ventricle (SV) circulations are at risk for ventricular dysfunction. This study investigates whether there is evidence of increased myocardial fibrosis and myocardial dysfunction in children after the Fontan operation. METHODS: Consecutive children after the Fontan operation who underwent cardiac magnetic resonance (CMR) T1 relaxometry with a modified look-locker inversion recovery approach were included in this retrospective study. Native T1 times (T1) and extracellular volume fractions (ECV) in the free wall of the dominant ventricle (left, SLV; right, SRV) were compared with controls and correlated with hemodynamic and clinical parameters. RESULTS: Twenty-one SV patients (9.7±4.6years; 13 SLV; 8 SRV) and 24 healthy control children (13.9±2.6years, p=0.002) were included. T1 and ECV were higher in SRV patients than in controls (1036±46ms vs 974±27ms, p<0.001; 28±4% vs 22±3%, p=0.002) and SLV patients (978±39ms, p=0.002; 23±5%, p=0.012) while there was no difference between SLV patients and controls. Age at bidirectional cavopulmonary connection was correlated with T1 (R=0.55, p=0.015), while systolic blood pressure (R=-0.68, p<0.001) and body weight (R=-0.54, p=0.012) inversely correlated with ECV. T1 negatively correlated with radial and circumferential strain by CMR feature tracking. CONCLUSIONS: Fontan patients with a SRV show increased CMR markers of diffuse myocardial fibrosis, which are associated with decreased myocardial contractility. Whether their increased fibrosis burden conveys a greater risk for long-term complications in this population remains to be investigated.

Improved Exercise Performance in Patients With Tricuspid Atresia After the Fontan-Björk Modification With Pulsatile Systolic Pulmonary Flow.

BACKGROUND: After the Fontan-Björk modification for tricuspid atresia, some patients show pulsatile systolic pulmonary flow. We compared the hemodynamic findings and the clinical presentation of patients with and without pulsatile systolic flow after atrioventricular connection. METHODS: According to the pulmonary flow pattern by pulsed-wave Doppler assessment of transthoracic echocardiography, 41 patients after atrioventricular connection were divided into two groups: patients who showed dominant pulsatile systolic pulmonary flow (group P, n = 11), and patients who did not (group N, n = 30). RESULTS: Mean follow-up time was 27.8 ± 4.7 years in group P and 25.3 ± 3.8 years in group N (p = 0.1). Patients in group P had significantly less frequently catheter ablation procedures for tachyarrhythmia (9% versus 50%, p = 0.03). No patient in group P had had cardiac decompensation, whereas 7 patients (23%) in group N had had an episode of cardiac decompensation (p = 0.08). Cardiopulmonary exercise testing revealed that patients in group P showed higher oxygen uptake compared with patients in group N (25.0 ± 7.3 versus 19.6 ± 6.0 mL · kg(-1) · min(-1), p = 0.03). Patients in group P showed higher systolic pulmonary artery pressure (21.3 ± 8.4 versus 16.8 ± 4.5 mm Hg, p = 0.05), higher right ventricular end-diastolic volume index (88.6 ± 30.2 versus 50.3 ± 28.5 mL · L(-1) · m(-2), p = 0.03), and higher right ventricle to left ventricle ratio of end-diastolic volume index (1.4 ± 0.6 to 0.7 ± 0.3, p = 0.01). CONCLUSIONS: Patients with pulsatile systolic flow in the pulmonary artery had better hemodynamic and better exercise performance compared with patients without pulsatile systolic flow after atrioventricular connection. A sufficient volume and function of the right ventricle is a prerequisite to create pulsatile systolic flow.

Successful staged Fontan completion for a tricuspid atresia patient with left ventricular non-compaction.

We report a case of Fontan completion for a tricuspid atresia (TA) patient with left ventricular non-compaction (LVNC). The patient was diagnosed with TA (Ia) with LVNC by fetal echocardiography. Because the unfavourable prognosis of LVNC was anticipated, Imidapril as well as Carvedilol were administered to improve cardiac function, from the early stages of infancy. Staged Fontan completion with fenestration was successfully achieved with improvement of LV function.

Surgical management of competing pulmonary blood flow affects survival before Fontan/Kreutzer completion in patients with tricuspid atresia type I.

OBJECTIVES: To determine the association between surgical management of pulmonary blood flow (PBF) at initial and staged procedures with survival to Fontan/Kreutzer operation (Fontan) in patients with tricuspid atresia. METHODS: Infants aged <3 months with tricuspid atresia type I (n = 303) were enrolled from 34 institutions (1999-2013). Among those who underwent surgical intervention (n = 302), initial procedures were: systemic to pulmonary artery shunt (SPS; n = 189; 62%); pulmonary artery banding (PAB; n = 50; 17%); and superior cavopulmonary connection (SCPC; n = 63; 21%). Multiphase parametric-hazard models were used to analyze competing outcomes. RESULTS: Risk-adjusted 6-year survival was lower after SPS (85%; P = .04) versus PAB (93%) or SCPC (93%). Survival after SPS when the main pulmonary artery (MPA) was closed (n = 21) or banded (n = 4) was 60%, versus 93% without MPA intervention (P = .02). After SPS, survival before SCPC was lower with an open ductus arteriosus (n = 7; 76% vs 97%; P = .02). Similarly, after SPS, risk-adjusted survival was similar to that for patients who had an initial PAB or SCPC when MPA intervention was avoided and the ductus arteriosus either closed spontaneously before SPS, or was closed during SPS. For all patients reaching SCPC (n = 277), survival to Fontan was not significantly influenced by whether PBF persisted through the MPA. CONCLUSIONS: Tricuspid atresia patients with SPS represent a high-risk subgroup. Avoiding an open ductus arteriosus and concomitant MPA intervention during SPS may help mitigate the risk associated with SPS. The presence of antegrade PBF through the MPA, at initial and staged operations, did not significantly influence survival to Fontan operation.

Canonical wnt signaling regulates atrioventricular junction programming and electrophysiological properties.

RATIONALE: Proper patterning of the atrioventricular canal (AVC) is essential for delay of electrical impulses between atria and ventricles, and defects in AVC maturation can result in congenital heart disease. OBJECTIVE: To determine the role of canonical Wnt signaling in the myocardium during AVC development. METHODS AND RESULTS: We used a novel allele of ß-catenin that preserves ß-catenin's cell adhesive functions but disrupts canonical Wnt signaling, allowing us to probe the effects of Wnt loss of function independently. We show that the loss of canonical Wnt signaling in the myocardium results in tricuspid atresia with hypoplastic right ventricle associated with the loss of AVC myocardium. In contrast, ectopic activation of Wnt signaling was sufficient to induce formation of ectopic AV junction-like tissue as assessed by morphology, gene expression, and electrophysiological criteria. Aberrant AVC development can lead to ventricular pre-excitation, a characteristic feature of Wolff-Parkinson-White syndrome. We demonstrate that postnatal activation of Notch signaling downregulates canonical Wnt targets within the AV junction. Stabilization of ß-catenin protein levels can rescue Notch-mediated ventricular pre-excitation and dysregulated ion channel gene expression. CONCLUSIONS: Our data demonstrate that myocardial canonical Wnt signaling is an important regulator of AVC maturation and electric programming upstream of Tbx3. Our data further suggest that ventricular pre-excitation may require both morphological patterning defects, as well as myocardial lineage reprogramming, to allow robust conduction across accessory pathway tissue.

Slow pathway modulation in a patient with tricuspid valve atresia.

Owing to increased life expectancy, patients with grown-up congenital heart disease nowadays present various types of arrhythmias. We report treatment of a 27-year-old patient with tricuspid and pulmonary atresia who was referred to our department with symptomatic tachycardia. During electrophysiologic study, a diagnosis of typical AV-nodal re-entrant tachycardia was made, and he was successfully treated despite the described anatomic malformation.

A case of Seckel syndrome with tricuspid atresia.

Seckel syndrome is an autosomal recessive disease presenting with marked growth retardation, microcephalic dwarfism, some facial and skeletal abnormalities. Tricuspid atresia is a rare and life threatening cyanotic congenital heart diseases, with an incidence of 1% to 3%. It is feature of the anatomically normally related great arteries with a large ventricular septum defect and stenosis of right ventricular outflow tract. Tricuspid atresia has never been reported in patients with Seckel syndrome. Here we report a 15-day-old girl baby diagnosed as having Seckel syndrome with tricuspid atresia.

Heterogeneity of regional function and relation to ventricular morphology in patients with fontan circulation.

The relation between underlying ventricular morphology and regional function in patients with Fontan circulation remains unclear. The aim of this study was to compare regional function and its heterogeneity in patients with tricuspid atresia (TA), biventricular apex-forming morphology (BiV), and controls. Nineteen patients (median age 12 years) with Fontan circulation who presented consecutively were prospectively enrolled and compared with age- and heart rate-matched controls. Most patients were in New York Heart Association class I (63%). Longitudinal systolic strain (S), systolic strain rate (SRsys), and early diastolic strain rate (SRdia) peaks were obtained from 6 ventricular segments, and a coefficient of variation by segment was calculated as a measure of regional heterogeneity. Systolic S, SRsys and SRdia peaks were decreased at the right and left lateral walls in both patient groups compared with controls (p ≤0.001 for all). Patients with TA had higher systolic S and SRsys in the middle of the right lateral wall than those with BiV morphology (p = 0.009 and p = 0.001, respectively). The mean coefficients of variation assessed by S and SRsys were similar in controls and patients with TA but lower in those with BiV than in controls and patients with TA (p <0.001 and p = 0.01, respectively). The mean coefficient of variation assessed by SRdia was greater only in patients with BiV than in controls (p = 0.001). In conclusion, patients with Fontan circulation have more heterogeneous systolic and early diastolic regional function than healthy control subjects, and patients with TA have better systolic regional function in the middle of the right lateral wall and less systolic heterogeneity than patients with BiV morphology.