Effectiveness of Dexmedetomidine as Myocardial Protector in Children With Classic Tetralogy of Fallot Having Corrective Surgery: A Randomized Controlled Trial

OBJECTIVES

Efficacy of dexmedetomidine (DEX) as a cardioprotective agent in Indonesian children undergoing classic tetralogy of Fallot (TOF) repair with cardiopulmonary bypass (CPB).

DESIGN

A prospective, parallel trial using block randomization along with double-blinded preparation of treatment agents by other parties.

SETTING

National Cardiovascular Center Harapan Kita, Indonesia.

PARTICIPANTS

Sixty-six children with classic TOF scheduled for corrective surgery. No children were excluded. All patients had fulfilled the criteria for analysis.

INTERVENTIONS

A total of 0.5 µg/kg bolus of DEX was added to the CPB priming solution, followed by 0.25 µg/kg/h maintenance during bypass. The placebo group used normal saline. Follow-ups were up to 30 days.

MEASUREMENTS AND MAIN RESULTS

Troponin I was lower in the DEX group at 6 hours (30.48 ± 19.33 v 42.73 ± 27.16, p = 0.039) and 24 hours after CPB (8.89 ± 5.42 v 14.04 ± 11.17, p = 0.02). Within a similar timeframe, DEX successfully lowered interleukin-6 (p = 0.03; p = 0.035, respectively). Lactate was lower in the Dex group at 1, 6, and 24 hours after CPB (p < 0.01; p = 0.048; p = 0.035; respectively). Dexmedetomidine increased cardiac output and index from 6 hours after bypass, but vice versa in systemic vascular resistance. Reduction of vasoactive inotropic score was seen during intensive care unit monitoring in the Dex group (p = 0.049). Nevertheless, DEX did not significantly affect the length of ventilation (p = 0.313), intensive care unit stay (p = 0.087), and mortality (p > 0.99).

CONCLUSIONS

Dexmedetomidine during CPB is an effective cardioprotective agent in TOF children having surgery. Postoperative mortality was comparable across groups.

De novo start-loss variant in HIRA in patient with DiGeorge-like syndrome

A case of a newborn with tetralogy of Fallot, corpus callosum hypoplasia, and phenotypic features similar to DiGeorge syndrome. Chromosomal microarray analysis did not reveal any alterations. Whole exome sequencing and Sanger sequencing identified a de novo variant in the HIRA gene resulting in the loss of the start codon.

Assessment of Pulmonary Arterial Vascular Impedance in Fetuses With Tetralogy of Fallot

OBJECTIVE

To evaluate the vascular impedance of the pulmonary arteries in fetuses with tetralogy of Fallot (TOF) by Doppler echocardiography.

METHODS

A total of 42 fetuses with TOF (TOF group) and 84 gestational age-matched normal fetuses (control group) were prospectively collected from the Second Xiangya Hospital of Central South University from August 2022 to January 2023. The severity of TOF was classified into mild TOF (z score ≥-2), moderate TOF (-4 < z score < -2), or severe TOF (z score ≤-4) according to the z score value of the pulmonary annulus diameter. The pulsatility index (PI) of the main pulmonary artery (MPA), distal left pulmonary artery (DLPA), and distal right pulmonary artery (DRPA) were measured by pulsed-wave Doppler. The differences in clinical data and echocardiographic parameters between TOF group, control group, and TOF subgroups were compared.

RESULTS

Compared with the control group, MPA-PI increased significantly, whereas DLPA-PI and DRPA-PI decreased in TOF group (all P < .001). There were no significant differences in MPA-PI and DRPA-PI among mild TOF, moderate TOF, and severe TOF (all P > .05). However, DLPA-PI decreased significantly in severe TOF compared with mild TOF (P < .05).

CONCLUSION

Fetuses with TOF presented increased vascular impedance in the pulmonary trunk and decreased impedance in distal pulmonary artery branches. Further large and follow-up studies are needed to demonstrate the associations between those changed vascular impedances and the development of PA in patients with TOF.

Repaired Tetralogy of Fallot: Have We Understood the Right Timing of PVR?

Despite many advances in surgical repair during the past few decades, the majority of tetralogy of Fallot patients continue to experience residual hemodynamic and electrophysiological abnormalities. The actual issue, which has yet to be solved, is understanding how this disease evolves in each individual patient and, as a result, who is truly at risk of sudden death, as well as the proper timing of pulmonary valve replacement (PVR). Our responsibility should be to select the most appropriate time for each patient, going above and beyond imaging criteria used up to now to make such a clinically crucial decision. Despite several studies on timing, indications, procedures, and outcomes of PVR, there is still much uncertainty about whether PVR reduces arrhythmia burden or improves survival in these patients and how to appropriately manage this population. This review summarizes the most recent research on the evolution of repaired tetralogy of Fallot (from adolescence onwards) and risk factor variables that may favor or delay PVR.

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.

THE EFFECTS OF PREGNANCY IN SUBJECTS WITH REPAIRED TETRALOGY OF FALLOT

BACKGROUND

Previous reports reveal inconsistent findings of right ventricular (RV) changes following pregnancy in subjects with repaired tetralogy of Fallot (rTOF).

METHODS

A two-center, retrospective cohort study which included women with rTOF who completed pregnancy that were matched to nulliparous women with rTOF by age at the time of baseline cardiac magnetic resonance (CMR), RV ejection fraction (RVEF), and indexed RV end-diastolic volume (RVEDVi). Pre-pregnancy and postpartum cardiac magnetic resonance (CMR) were analyzed and compared to sequential CMR of nulliparous subjects with rTOF.

RESULTS

Thirty-six women with rTOF who completed pregnancy were matched to 72 nulliparous women with rTOF. Over a mean period of 3.1 years for the pregnancy group and 2.7 years for the comparison group, there was no significant change in the RVEDVi, RVEF, RV mass, pulmonary regurgitation severity, left ventricular (LV) volumes, LV ejection fraction (LVEF), or LV mass when comparing the baseline CMR and the follow-up CMR in either of the groups. There was a slight increase in RV indexed end-systolic volume (RVESVi) when comparing the baseline CMR and the follow-up CMR in the pregnancy group (68.93, SD 23.34 ml/m2 at baseline vs. 72.97, SD 25.24 ml/m2 at follow-up, p= 0.028). Using a mixed effects model for CMR parameters change over time; when adjusted for time between baseline and follow-up CMR there was no significant difference in rate of change between the pregnancy and comparison groups.

CONCLUSIONS

Most ventricular remodeling parameters measured by CMR did not significantly change in subjects with rTOF who completed pregnancy or in nulliparous subjects with rTOF. In the pregnancy group, RVESVi is larger in those individuals who have undergone pregnancy without a significant change in ventricular function. These patients should be followed longitudinally to determine the long-term ventricular and clinical effects of pregnancy.

Deep learning-based differentiation of ventricular septal defect from tetralogy of Fallot in fetal echocardiography images

BACKGROUND

Congenital heart disease (CHD) seriously affects children's health and quality of life, and early detection of CHD can reduce its impact on children's health. Tetralogy of Fallot (TOF) and ventricular septal defect (VSD) are two types of CHD that have similarities in echocardiography. However, TOF has worse diagnosis and higher morality than VSD. Accurate differentiation between VSD and TOF is highly important for administrative property treatment and improving affected factors' diagnoses.

OBJECTIVE

TOF and VSD were differentiated using convolutional neural network (CNN) models that classified fetal echocardiography images.

METHODS

We collected 105 fetal echocardiography images of TOF and 96 images of VSD. Four CNN models, namely, VGG19, ResNet50, NTS-Net, and the weakly supervised data augmentation network (WSDAN), were used to differentiate the two congenital heart diseases. The performance of these four models was compared based on sensitivity, accuracy, specificity, and AUC.

RESULTS

VGG19 and ResNet50 performed similarly, with AUCs of 0.799 and 0.802, respectively. A superior performance was observed with NTS-Net and WSDAN specific for fine-grained image categorization tasks, with AUCs of 0.823 and 0.873, respectively. WSDAN had the best performance among all models tested.

CONCLUSIONS

WSDAN exhibited the best performance in differentiating between TOF and VSD and is worthy of further clinical popularization.

Effectiveness of pulmonary valve-sparing strategy for transatrial-transpulmonary repair of tetralogy of Fallot: a single institution experience

OBJECTIVE

We report the midterm results of our strategy utilizing transatrial-transpulmonary repair for tetralogy of Fallot at a single institution in a low-middle income country.

METHODS

Medical records were retrospectively reviewed for 532 consecutive patients who underwent definitive repair of tetralogy of Fallot at our institution from 2010 to 2020.

RESULTS

The median age and weight of patients in the study patients were 11.6 months (interquartile range, 8.6-17.2 months) and 7.5 kg (interquartile range, 6.8-8.8 kg). The pulmonary valve annulus was preserved (no transannular patch) in 398 patients (75%) and a mini-transannular patch was utilized for 134 patients (25%). The overall survival was 98% at 1 year, and 97% at 10-years follow-up, respectively. Longer postoperative ventilation time was the only risk factor correlated to early death (p = 0.004; Odds Risk, 1.04; 95% confidence intervals, 1.01-1.07). Fourteen patients required pulmonary valve replacement (2.6%, 14/532), four required surgical resection to relieve right ventricular outflow tract obstruction (0.8%, 4/532), and freedom from reoperation of the right ventricular outflow tract was 87% at 10 years. The only risk factor for right ventricular outflow tract reoperation was a postoperative systolic pressure gradient through the right ventricular outflow tract of greater than 50 mmHg (p < 0.001; HR, 47; 95% confidence intervals, 9.1-244). In total, 94.6% (471/489) of the patients were asymptomatic at the latest follow-up without significant arrhythmia.

CONCLUSION

At our institution in an low-middle income country, the transatrial-transpulmonary repair for tetralogy of Fallot has excellent midterm results with few reoperations required. Close long-term follow-up is essential for patients who undergo repair with a mini-transannular patch and may eventually require pulmonary valve replacement.

Transcatheter Pulmonary Valve Replacement With the Harmony Valve in Patients Who Do Not Meet Recommended Oversizing Criteria on the Screening Perimeter Plot

BACKGROUND

Anatomic selection for Harmony valve implant is determined with the aid of a screening report and perimeter plot (PP) that depicts the perimeter-derived radius along the right ventricular outflow tract (RVOT) and projects device oversizing. The PP provides an estimation of suitability for implant, but its sensitivity as a screening method is unknown. This study was performed to describe anatomic features and outcomes in patients who underwent Harmony TPV25 implant despite a PP that predicted inadequate oversizing.

METHODS

We reviewed RVOT anatomic features and measurements in patients who underwent transcatheter pulmonary valve replacement with the Harmony TPV25 device despite a PP that predicted inadequate oversizing.

RESULTS

This study included 22 patients. There were no unsuccessful implants or adverse valve-related events. Anatomic features varied, but all patients fit into 1 of 3 anatomic types characterized by differences in RVOT dimensions. Type 1 patients (n=9) had a long RVOT with a choke point and a wide main pulmonary artery. Type 2 patients (n=6) had a short RVOT that was pyramidal in shape, with no choke point, and extensive main pulmonary artery lengthening/expansion during systole. Type 3 patients (n=7) had a short, bulbous main pulmonary artery with a choke point and an open pulmonary artery bifurcation.

CONCLUSIONS

Transcatheter pulmonary valve replacement with the Harmony valve is feasible in some patients whose PP fit analysis predicts inadequate oversizing. All cases in this series fit into 1 of 3 anatomic patterns, which are not identified in the screening report. Implanters must review cases individually to assess the feasibility of the implant.

Impact of right ventriculotomy on cardiac function after pulmonary valve sparing repair of tetralogy of Fallot and double outlet right ventricle with pulmonary stenosis

OBJECTIVES

Pulmonary valve-sparing repair of tetralogy of Fallot and double outlet right ventricle with pulmonary stenosis has the advantage of reduced incidence of late pulmonary valve regurgitation and better-preserved cardiac function. However, a right ventriculotomy is sometimes necessary in order to adequately relieve subvalvular pulmonary stenosis. We aimed to compare postoperative cardiac function and patients' symptoms between pulmonary valve-sparing repair with and without right ventriculotomy.

MATERIALS AND METHODS

We retrospectively collected data from electronic medical records of Ramathibodi Hospital from 1st January 2013 to 31st October 2023. Patients diagnosed with tetralogy of Fallot and double outlet right ventricle with pulmonary stenosis who underwent pulmonary valve-sparing repair were included. Patients who underwent other types of repairs and whose medical record data were significantly missing were excluded. Demographic data, operative, and postoperative details were collected and reviewed.

RESULTS

There were 49 patients included in our study with 10 patients undergoing pulmonary valve-sparing repair with and the other 39 without right ventriculotomy. Before-discharge echocardiographic parameters were generally similar between both groups (tricuspid annular plane systolic excursion = 0.9 versus 0.89 cm, P = 0.737; pressure gradient across pulmonary valve across pulmonary valve = 24 versus 19 mmHg, P = 0.275; left ventricular end-systolic volume index = 17.84 versus 19.19 ml/m2, P = 0.437; left ventricular end-diastolic volume index = 63.79 versus 61.13 ml/m2, P = 0.436). Patients' symptoms were also not statistically different. There was no early and late death up to the end date of our study.

CONCLUSIONS

Right ventriculotomy in pulmonary valve-sparing repair did not result in worse postoperative cardiac function and symptoms. This suggested that the previously thought-to-be hazardous incision could be strongly considered if mandated.

Early Outcomes From a Multicenter Transcatheter Self-Expanding Pulmonary Valve Replacement Registry

BACKGROUND

Transcatheter pulmonary valve replacement (TPVR) with the self-expanding Harmony valve (Medtronic) is an emerging treatment for patients with native or surgically repaired right ventricular outflow tract (RVOT) pulmonary regurgitation (PR). Limited data are available since U.S. Food and Drug Administration approval in 2021.

OBJECTIVES

In this study, the authors sought to evaluate the safety and short-term effectiveness of self-expanding TPVR in a real-world experience.

METHODS

This was a multicenter registry study of consecutive patients with native RVOT PR who underwent TPVR through April 30, 2022, at 11 U.S.

CENTERS

The primary outcome was a composite of hemodynamic dysfunction (PR greater than mild and RVOT mean gradient >30 mm Hg) and RVOT reintervention.

RESULTS

A total of 243 patients underwent TPVR at a median age of 31 years (Q1-Q3: 19-45 years). Cardiac diagnoses were tetralogy of Fallot (71%), valvular pulmonary stenosis (21%), and other (8%). Acute technical success was achieved in all but 1 case. Procedural serious adverse events occurred in 4% of cases, with no device embolization or death. Hospital length of stay was 1 day in 86% of patients. Ventricular arrhythmia prompting treatment occurred in 19% of cases. At a median follow-up of 13 months (Q1-Q3: 8-19 months), 98% of patients had acceptable hemodynamic function. Estimated freedom from the composite clinical outcome was 99% at 1 year and 96% at 2 years. Freedom from TPVR-related endocarditis was 98% at 1 year. Five patients died from COVID-19 (n = 1), unknown causes (n = 2), and bloodstream infection (n = 2).

CONCLUSIONS

In this large multicenter real-world experience, short-term clinical and hemodynamic outcomes of self-expanding TPVR therapy were excellent. Ongoing follow-up of this cohort will provide important insights into long-term outcomes.

Bilateral remote ischemic conditioning in children: A two-center, double-blind, randomized controlled trial in young children undergoing cardiac surgery

Objective

The study objective was to determine whether adequately delivered bilateral remote ischemic preconditioning is cardioprotective in young children undergoing surgery for 2 common congenital heart defects with or without cyanosis.

Methods

We performed a prospective, double-blind, randomized controlled trial at 2 centers in the United Kingdom. Children aged 3 to 36 months undergoing tetralogy of Fallot repair or ventricular septal defect closure were randomized 1:1 to receive bilateral preconditioning or sham intervention. Participants were followed up until hospital discharge or 30 days. The primary outcome was area under the curve for high-sensitivity troponin-T in the first 24 hours after surgery, analyzed by intention-to-treat. Right atrial biopsies were obtained in selected participants.

Results

Between October 2016 and December 2020, 120 eligible children were randomized to receive bilateral preconditioning (n = 60) or sham intervention (n = 60). The primary outcome, area under the curve for high-sensitivity troponin-T, was higher in the preconditioning group (mean: 70.0 ± 50.9 μg/L/h, n = 56) than in controls (mean: 55.6 ± 30.1 μg/L/h, n = 58) (mean difference, 13.2 μg/L/h; 95% CI, 0.5-25.8; P = .04). Subgroup analyses did not show a differential treatment effect by oxygen saturations (pinteraction = .25), but there was evidence of a differential effect by underlying defect (pinteraction = .04). Secondary outcomes and myocardial metabolism, quantified in atrial biopsies, were not different between randomized groups.

Conclusions

Bilateral remote ischemic preconditioning does not attenuate myocardial injury in children undergoing surgical repair for congenital heart defects, and there was evidence of potential harm in unstented tetralogy of Fallot. The routine use of remote ischemic preconditioning cannot be recommended for myocardial protection during pediatric cardiac surgery.

Longitudinal ECG changes in tetralogy of Fallot and association with surgical repair

Background

ECG abnormalities have been linked to adverse changes in right ventricular (RV) morphology and poor clinical outcomes in repaired Tetralogy of Fallot (rTOF). Our aim was to describe how ECG changes progress in early and intermediate follow-up and whether types of surgical strategy at the time of primary repair affected these changes.

Methods

We studied patients with rTOF born 2000-2018 operated at our institution. Seven time points in relation to primary repair, follow-up, and pulmonary valve replacement (PVR) were identified. Patients correct with valve sparing repair (VSR), trans-annular patch (TAP) including with a monocusp valve (TAP + M) and with at least 3 ECGs were included. PQ interval, QRS duration, dispersion, and fragmentation, QTc duration and dispersion, JTc as well as presence of a right bundle branch block (RBBB) were analyzed. Medical records were reviewed for demographic and surgical data.

Results

Two hundred nineteen patients with 882 ECGs were analyzed with a median follow-up time of 12.3 years (8.4, 17) with 41 (19%) needing PVR during the study period. QRS duration increased at time of primary repair to discharge from 66 msec (IQR 12) to 129 msec (IQR 27) (p < 0.0001) and at 1- and 6- year follow-up but showed only a modest and temporary decrease after PVR. QTc increased at the time of primary repair as well as prior to PVR. PQ interval showed a small increase at the time of primary repair, was at its highest prior to PVR and decreased with PVR. Type of surgical repair affected mainly QTc and JTc and was consistently longer in the TAP + M group until PVR. In VSR, QTc and JTc were prolonged initially compared to TAP but were similar after 1 year. After PVR, there were no differences in adverse ECG changes between surgical groups.

Conclusions

PQ interval and QRS duration best correspond to the assumed volume load whereas the relationship with QTc and JTc is more complex, suggesting that these represent more complex remodeling of the myocardium. Before PVR, QTc and JTc are longer in the TAP + M group which may be due to a longer surgical incision.

A 4-month-old male with Raghib syndrome: a rare case report from Syria

Introduction and importance

Raghib syndrome is a rare congenital complication consisting of the termination of the left superior vena cava (LSVC) in the left atrium, an unroofed coronary sinus, and an atrial septal defect most often found in the posterior-inferior angle of the atrial septum. Both a right-to-left and a left-to-right intracardiac shunt exist. In most circumstances, they do not show any symptoms.

Presentation of case

The patient presented with a persistent left superior vena cava draining into the left atrium, an unroofed coronary sinus, and a secondary atrial septal defect (ASD). Transthoracic echocardiography was used to diagnose the condition, and surgery was applied as the primary treatment.

Clinical discussion

It was formerly believed that this complex was exclusive to Raghib syndrome; however, cases have been found in which the interatrial connection is the aperture of the unroofed coronary sinus in patients with a normal atrial septum.

Conclusion

Extracardiac treatment for this illness reduces the load on the left atrial suture and may stop further arrhythmias. There is no possibility of pulmonary vein flow restriction when there are no atrial tunnels.

Percutaneous pulmonary valve implantation in a patient with a single pulmonary artery and distal narrowing

Percutaneous pulmonary valve implantation is established as a safe and effective method of treating patients with disfunction of right ventricular outflow tract. Modifications of this method allow for an increasingly wider use of this less invasive treatment. We present a staged percutaneous pulmonary valve implantation into a single-branch pulmonary artery in a paediatric patient with tetralogy of Fallot after patch repair.

Long-Term Outcomes of Cardiac Resynchronization Therapy in Patients With Repaired Tetralogy of Fallot: A Multicenter Study

BACKGROUND

A growing number of patients with tetralogy of Fallot develop left ventricular systolic dysfunction and heart failure, in addition to right ventricular dysfunction. Although cardiac resynchronization therapy (CRT) is an established treatment option, the effect of CRT in this population is still not well defined. This study aimed to investigate the early and late efficacy, survival, and safety of CRT in patients with tetralogy of Fallot.

METHODS

Data were analyzed from an observational, retrospective, multicenter cohort, initiated jointly by the Pediatric and Congenital Electrophysiology Society and the International Society of Adult Congenital Heart Disease. Twelve centers contributed baseline and longitudinal data, including vital status, left ventricular ejection fraction (LVEF), QRS duration, and NYHA functional class. Outcomes were analyzed at early (3 months), intermediate (1 year), and late follow-up (≥2 years) after CRT implantation.

RESULTS

A total of 44 patients (40.3±19.2 years) with tetralogy of Fallot and CRT were enrolled. Twenty-nine (65.9%) patients had right ventricular pacing before CRT upgrade. The left ventricular ejection fraction improved from 32% [24%-44%] at baseline to 42% [32%-50%] at early follow-up (P<0.001) and remained improved from baseline thereafter (P≤0.002). The QRS duration decreased from 180 [160-205] ms at baseline to 152 [133-182] ms at early follow-up (P<0.001) and remained decreased at intermediate and late follow-up (P≤0.001). Patients with upgraded CRT had consistent improvement in left ventricular ejection fraction and QRS duration at each time point (P≤0.004). Patients had a significantly improved New York Heart Association functional class after CRT implantation at each time point compared with baseline (P≤0.002). The transplant-free survival rates at 3, 5, and 8 years after CRT implantation were 85%, 79%, and 73%.

CONCLUSIONS

In patients with tetralogy of Fallot treated with CRT consistent improvement in QRS duration, left ventricular ejection fraction, New York Heart Association functional class, and reasonable long-term survival were observed. The findings from this multicenter study support the consideration of CRT in this unique population.

Multidetector Computed Tomography Assessment of Anatomical Ventricular Tachycardia Isthmuses in Repaired Tetralogy of Fallot

BACKGROUND

Tetralogy of Fallot (TOF) is associated with risk for sustained monomorphic ventricular tachycardia (VT). Preemptive electrophysiology study before transcatheter pulmonary valve placement is increasing, but the value of MDCT for anatomical VT isthmus assessment is unknown.

OBJECTIVES

The purpose of this study was to determine the impact of multidetector computed tomography (MDCT) in the evaluation of sustained monomorphic VT for repaired TOF.

METHODS

Consecutive pre-transcatheter pulmonary valve MDCT studies were identified, and anatomical isthmus dimensions were measured. For a subset of patients with preemptive electrophysiology study, MDCT features were compared with electroanatomical maps.

RESULTS

A total of 61 repaired TOFs with MDCT were identified (mean 35 ± 14 years, 58% men) with MDCT electroanatomical map pairs in 35 (57%). Calcification corresponding to patch material was present in 46 (75%) and was used to measure anatomical VT isthmuses. MDCT wall thickness correlated positively with number of ablation lesions and varied with functional isthmus properties (blocked isthmus 2.6 mm [Q1, Q3: 2.1, 4.0 mm], slow conduction 4.8 mm [Q1, Q3: 3.3, 6.0 mm], and normal conduction 5.6 mm [Q1, Q3: 3.9, 8.3 mm]; P < 0.001). A large conal branch was present in 6 (10%) and a major coronary anomaly was discovered in 3 (5%). Median ablation lesion distance was closer to the right vs the left coronary artery (10 mm vs 15 mm; P = 0.01) with lesion-to-coronary distance <5 mm in 3 patients.

CONCLUSIONS

MDCT identifies anatomical structures relevant to catheter ablation for repaired TOF. Wall thickness at commonly targeted anatomical VT isthmuses is associated with functional isthmus properties and increased thermal energy delivery.

Hybrid Stent Implantation Into Right Ventricular Outflow Tract in a Newborn With Tetralogy of Fallot

A case is presented of a newborn with tetralogy of Fallot and aortic coarctation. Progressive right ventricular outflow tract (RVOT) obstruction required urgent surgical therapy. Coronary artery crossing the outflow tract made ventriculotomy impossible. Hybrid RVOT stent implantation was performed, providing effective pulmonary flow and enabling postponing of corrective jumping graft implantation.

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.

Right ventricular outflow tract stenting for late presenter unrepaired Fallot physiology: a single-center experience

Objectives

The purpose of this study was to assess the clinical outcome after right ventricular outflow tract (RVOT) stenting in late presenter patient with unrepaired Fallot physiology.

Background

In younger patients, RVOT stenting is an alternative to mBTT shunt; however, there have been few reports of this palliative technique in late presenter population, including adults.

Methods

This was a single-center, retrospective study of nonrandomized, palliated Fallot patients. Clinical outcomes such as left ventricular ejection fraction and saturation were measured in 32 individuals following RVOT stenting in adults (n = 10) and children (n = 22). The Statistical Package for Social Science (SPSS) 26.0 software was used to analyze the statistical data.

Results

During the procedure, the average stent diameter and length were 8.84 ± 1.64 mm and 35.46 ± 11.23 mm, respectively. Adult patients received slightly longer stents than pediatric patients (43.60 ± 11.64 mm vs. 31.77 ± 9.07 mm). Overall, patients' saturation increased from 58.56 ± 19.03% to 91.03 ± 8.98% (p < 0.001), as did their left ventricular ejection fraction (LVEF) from 64.00 ± 18.21% to 75.09 ± 12.98% (p = 0.001). Three patients improved their LVEF from 31 to 55%, 31 to 67%, and 26 to 50%. The median length of stay was 8 (2-35) days, with an ICU stay of 2 (0-30) days. The median time from RVOT stent palliation to total repair was 3 months (range: 1 month-12 months).

Conclusions

RVOT stenting is a safe and effective method for increasing saturation and ejection fraction not only in newborn infants but also in late presenters, including adults with unrepaired Fallot physiology.

Impact of pulmonary stenosis on right ventricular global longitudinal strain in repaired tetralogy of Fallot patients post transcatheter pulmonary valve replacement

BACKGROUND

Mixed pulmonary disease with pulmonary regurgitation (PR) and stenosis (PS) in repaired tetralogy of Fallot (rTOF) can negatively impact ventricular health. Myocardial strain has been shown to be more sensitive at detecting occult ventricular dysfunction compared to right ventricular ejection fraction (RV EF). We hypothesize that rTOF patients with predominant PS will have lower RV global longitudinal strain (RV GLS) prior to and post-transcatheter pulmonary valve replacement (TPVR).

METHODS

A retrospective cohort of rTOF patients who underwent cardiac magnetic resonance (CMR) and cardiac catheterization for right ventricular pressure (RVSP) measurement were analyzed at three time points: before valve implantation, at discharge and within 18 months post-TPVR. Patients were dichotomized into three groups based on RVSP: 0%-49%, 50%-74%, and >75%. RV GLS and left ventricular (LV) GLS by speckle tracking echocardiography (STE) were obtained from the apical 4-chamber using TomTec software (TOMTEC IS, Germany).

RESULTS

Forty-eight patients were included. Every 14.3% increase in preimplantation RVSP above 28% was associated with an absolute magnitude 1% lower RV GLS (p = .001). Preimplantation RVSP when 75% or higher had 3.36% worse RV GLS than the lowest bin (p = .014). Overall, average RV strain magnitude was higher when preimplantation RVSP was less than 50% and had greater improvement over the three time points. Higher post implantation RVSP correlated with lower strain magnitude.

CONCLUSION

Patients with significant PS (>50%) may benefit from earlier PVR and not depend solely on RV size and EF. Myocardial strain may be a more sensitive marker of function; however, larger, prospective studies are needed.

Somatic GATA4 mutation contributes to tetralogy of Fallot

Tetralogy of Fallot (TOF) is the most prevalent cyanotic congenital heart pathology and causes infant morbidity and mortality worldwide. GATA-binding protein 4 (GATA4) serves as a pivotal transcriptional factor for embryonic cardiogenesis and germline GATA4 mutations are causally linked to TOF. However, the effects of somatic GATA4 mutations on the pathogenesis of TOF remain to be ascertained. In the present study, sequencing assay of GATA4 was performed utilizing genomic DNA derived from resected heart tissue specimens as well as matched peripheral blood specimens of 62 patients with non-familial TOF who underwent surgical treatment for TOF. Sequencing of GATA4 was also performed using the heart tissue specimens as well as matched peripheral venous blood samples of 68 sporadic cases who underwent heart valve displacement because of rheumatic heart disorder and the peripheral venous whole blood samples of 216 healthy subjects. The function of the mutant was explored by dual-luciferase activity analysis. Consequently, a new GATA4 mutation, NM_002052.5:c.708T>G;p.(Tyr236*), was found in the heart tissue of one patient with TOF. No mutation was detected in the heart tissue of the 68 cases suffering from rheumatic heart disorder or in the venous blood samples of all 346 individuals. GATA4 mutant failed to transactivate its target gene, myosin heavy chain 6. Additionally, this mutation nullified the synergistic transactivation between GATA4 and T-box transcription factor 5 or NK2 homeobox 5, two genes causative for TOF. Somatic GATA4 mutation predisposes TOF, highlighting the significant contribution of somatic variations to the molecular pathogenesis underpinning TOF.

Technical performance scores associate with early prognosis of tetralogy of Fallot repair

Objective

This study aimed to investigate the relationship between technical performance scores (TPS) and the early prognosis of tetralogy of Fallot repair (TOF).

Methods

A retrospective study was conducted on TOF repair patients at our center from Oct 2017 to Oct 2022. Patients were classified into Class 1 (no residua), Class 2 (minor residua), or Class 3 (major residua) based on TPS derived from predischarge echocardiograms and need for reintervention. Statistical methods were used to assess the association between TPS and early prognosis.

Results

A total of 75 TOF repair patients (40% female, 60% male) were analyzed and categorized into TPS1 (24%), TPS2 (53.3%), and TPS3 (22.6%) based on pre-discharge echocardiographic findings. The median follow-up time was 7.0 months. The multivariable Cox regression analysis indicated that TPS3 scores are associated with a 12.68-fold increase in risk compared to TPS1 and TPS2 scores [95% CI = 12.68 (0.9∼179.28), P = 0.06]. The Spearman rank correlation analysis revealed a weak positive correlation between TPS classification and low cardiac output syndrome (r = 0.26, P = 0.03). However, there were no significant differences in ICU stay or duration of mechanical ventilation among the groups.

Conclusion

TPS3 after intracardiac TOF repair is associated with higher risk of early re-intervention, highlighting the importance of close follow-up and monitoring in this patient population. Patients who develop low cardiac output syndrome in the early postoperative period may have residual defects that require prompt identification.

Congenital heart defects in Arabian horses and the prospects of genetic testing: A review

Congenital heart defects (CHDs) can have profound and potentially life-threatening consequences on horses' health and performance capability. While CHDs are rare in the general horse population, the Arabian breed is disproportionately overrepresented and thus is widely suspected to be genetically predisposed. This review discusses the most common CHDs in Arabian horses, including ventricular septal defect (VSD), tetralogy of Fallot (TOF), patent duct arteriosus (PDA), tricuspid valve atresia (TVA) and atrial septal defect (ASD). This review also explores how future research into the genetic factors that likely underpin many CHDs can revolutionise the way these disorders are managed in Arabian horses.

Pulmonary Valve Replacement in Tetralogy of Fallot: Procedural Volume and Durability of Bioprosthetic Pulmonary Valves

BACKGROUND

Robust data on changes in pulmonary valve replacement (PVR) procedural volume and predictors of bioprosthetic pulmonary valve (BPV) durability in patients with tetralogy of Fallot (TOF) are scarce.

OBJECTIVES

This study sought to assess temporal trends in PVR procedural volume and BPV durability in a nationwide, retrospective TOF cohort.

METHODS

Data were obtained from patient records. Robust linear regression was used to assess temporal trends in PVR procedural volume. Piecewise exponential additive mixed models were used to estimate BPV durability, defined as the time from implantation to redo PVR with death as a competing risk, and to assess risk factors for reduced durability.

RESULTS

In total, 546 PVR were performed in 384 patients from 1976 to 2021. The annual number of PVR increased from 0.4 to 6.0 per million population (P < 0.001). In the last decade, the transcatheter PVR volume increased by 20% annually (P < 0.001), whereas the surgical PVR volume did not change significantly. The median BPV durability was 17 years (Q1: 10-Q3: 10 years-not applicable). There was no significant difference in the durability of different BPV after adjustment for confounders. Age at PVR (HR: 0.78 per 10 years from <1 year; 95% CI: 0.63-0.96; P = 0.02) and true inner valve diameter (9-17 mm vs 18-22 mm HR: 0.40; 95% CI: 0.22-0.73; P = 0.003 and 18-22 mm vs 23-30 mm HR: 0.59; 95% CI: 0.25-1.39; P = 0.23) were associated with reduced BPV durability in multivariate models.

CONCLUSIONS

The PVR procedural volume has increased over time, with a greater increment in transcatheter than surgical PVR during the last decade. Younger patient age at PVR and a smaller true inner valve diameter predicted reduced BPV durability.

Transcatheter Pulmonary Valve Replacement With Balloon-Expandable Valves: Utilization and Procedural Outcomes From the IMPACT Registry

BACKGROUND

Transcatheter pulmonary valve replacement (TPVR) has expanded and evolved since its initial commercial approval in the United States in 2010.

OBJECTIVES

This study sought to characterize real-world practice, including patient selection, procedural outcomes, complications, and off-label usage.

METHODS

Characteristics and outcomes for patients undergoing balloon-expandable TPVR were collected from the American College of Cardiology National Cardiovascular Data Registry IMPACT (Improving Pediatric and Adult Congenital Treatment) Registry.

RESULTS

Between April 2016 and March 2021, 4,513 TPVR procedures were performed in patients with a median age of 19 years, 57% with a Melody (Medtronic Inc) and 43% with a SAPIEN (Edwards Lifesciences) valve. Most implanting centers performed <10 cases annually. One-third of transcatheter pulmonary valve implants were into homograft conduits, one-third were into bioprosthetic valves (BPVs), 25% were in native or patched right ventricular outflow tracts (RVOTs), and 6% were into Contegra (Medtronic Inc) conduits. Over the course of the study period, SAPIEN valve use grew from ∼25% to 60%, in large part because of implants in patients with a native/patched RVOT. Acute success was achieved in 95% of patients (95.7% in homografts, 96.2% in BPVs, 94.2% in native RVOTs, and 95.4% in Contegra conduits). Major adverse events occurred in 2.4% of procedures, more commonly in patients with a homograft (2.9%) or native RVOT (3.4%) than a prior BPV (1.4%; P = 0.004).

CONCLUSIONS

This study describes novel population data on the use and procedural outcomes of TPVR with balloon-expandable valves. Over time, there has been increasing use of TPVR to treat regurgitant native RVOT anatomy, with the SAPIEN valve more commonly used for this application.

Risk Factors Associated With Prolonged Mechanical Ventilation and Length of Stay After Repair of Tetralogy of Fallot

BACKGROUND

This study examined preoperative, intraoperative, and postoperative data to identify factors that are associated with prolonged mechanical ventilation (PMV) and prolonged intensive care unit length of stay (ICU LOS) in tetralogy of Fallot (TOF) patients undergoing repair surgery.

METHODS

A retrospective study was carried out after approval from the institutional review board. All patients (age 0-52 years) who underwent TOF repair from January 2016 to September 2022 were included. Prolonged mechanical ventilation was defined as >24 h of ventilation, while prolonged ICU LOS was defined as ICU stay >3 days.

RESULTS

A total of 922 patients were included, among whom 288 (31.2%) were intubated for >24 h and 222 (24.1%) stayed in ICU for >3 days. Younger age (odds ratio [OR] = 2, 95% confidence interval [CI] 1.2-3.3, P = .007), lower weight (OR = 2.1, 95% CI 1.2-3.5, P = .003), and residual lesion (OR = 3.27, 95% CI 1.2-8.7, P = .017) were associated with PMV. Moreover, independent risk factors for prolonged ICU LOS are similar to PMV risk factors, including younger age (OR = 2.3, 95% CI 1.28-4.12, P = .005), lower weight (OR = 2.83, 95% CI 1.58-5, P < .001), underweight status (OR = 1.7, 95% CI 1.12-2.57, P = .012), and residual lesion (OR = 3.79, 95% CI 1.43-10.05, P = .007). Both aortic cross-clamp and cardiopulmonary bypass times did not exhibit clinically significant risk factors toward PMV and prolonged ICU LOS.

CONCLUSIONS

The risk factors for PMV and prolonged ICU LOS were residual lesion, younger age, and lower weight. Nutritional status contributed to the risk of prolonged ICU LOS, but not PMV. Consideration of these factors may provide optimal care to improve the outcome following TOF corrective surgery.

Meta-analysis reveals differential gene expression in tetralogy of Fallot versus controls

OBJECTIVES

Tetralogy of Fallot (TOF) is the most common cyanotic congenital heart defect in the United States. We aimed to identify genetic variations associated with TOF using meta-analysis of publicly available digital samples to spotlight targets for prevention, screening, and treatment strategies.

METHODS

We used the Search Tag Analyze Resource for Gene Expression Omnibus (STARGEO) platform to identify 39 TOF and 19 non-TOF right ventricle tissue samples from microarray data and identified upregulated and downregulated genes. Associated gene expression data were analyzed using ingenuity pathway analysis and restricted to genes with a statistically significant (p < .05) difference and an absolute experimental log ratio >0.1 between disease and control samples.

RESULTS

Our analysis identified 220 genes whose expression profiles were significantly altered in TOF vs. non-TOF samples. The most striking differences identified in gene expression included genes FBXO32, PTGES, MYL12a, and NR2F2. Some top associated canonical pathways included adrenergic signaling, estrogen receptor signaling, and the role of NFAT in cardiac hypertrophy. In general, genes involved in adaptive, defensive, and reparative cardiovascular responses showed altered expression in TOF vs. non-TOF samples.

CONCLUSIONS

We introduced the interpretation of open "big data" using the STARGEO platform to define robust genomic signatures of congenital heart disease pathology of TOF. Overall, our meta-analysis results indicated increased metabolism, inflammation, and altered gene expression in TOF patients. Estrogen receptor signaling and the role of NFAT in cardiac hypertrophy represent unique pathways upregulated in TOF patients and are potential targets for future pharmacologic treatments.

How best can we name the channels seen in the setting of deficient ventricular septation?

Surgical repair of channels between the ventricles is enhanced when the surgeon knows precisely where to place a patch, or baffle, so as to restore septal integrity. The paediatric cardiologist should provide the necessary information. Communication will be enhanced if the same words are used to account for the structures in question. Currently, however, the same term, namely "ventricular septal defect," is used to account for markedly different areas within the heart. Closure of perimembranous defects found in hearts with concordant or discordant ventriculo-arterial connections restores the integrity of the ventricular septum, at the same time separating the systemic and pulmonary blood streams. When both arterial trunks arise from the right ventricle, in contrast, the surgeon when placing a baffle so as to separate the blood streams, does not close the channel most frequently described as the "ventricular septal defect." In this review, we show that the perimembranous lesions as found in hearts with concordant or discordant ventriculo-arterial connections are the right ventricular entrances to the areas subtended beneath the hinges of the leaflets of the aortic or pulmonary valves. When both arterial trunks arise from the right ventricle, and the channel between the ventricles is directly subaortic, then the channel termed the "ventricular septal defect" is the left ventricular entrance to the comparable space subtended beneath the aortic root. We argue that recognition of these fundamental anatomical differences enhances the appreciation of the underlying morphology of the various lesions that reflect transfer, during cardiac development, of the aortic root from the morphologically right to the morphologically left ventricle.

Tetralogy of Fallot: Hypoxia, the villain of the story?

BACKGROUND

Tetralogy of Fallot (ToF) is a cyanotic congenital heart disease, composed of four malformations: persistent communication between the right and the left ventricle, pulmonary stenosis, overriding aorta, and right ventricle hypertrophy. The etiology of this disease is not entirely known as yet, but it has been proposed that the pathology has genetic components. During embryonic development, the fetus is exposed to a physiological hypoxia to facilitate the formation of blood vessels and blood cells through de novo processes.

METHODS

After researching scientific databases on the implications of oxygen on the normal and abnormal development of organs, especially the heart, we were able to propose that oxygen deprivation may be the cause of the disease.

RESULTS

During this period, the hypoxia-inducible factor is activated and triggers transcriptional responses that enable adaptation to the hypoxic environment through angiogenic activation. High levels of this protein can alter certain physiological pathways, such as those related to the vascular endothelial growth factor. Research has shown that prolonged oxygen deprivation during embryological development can lead to the occurrence of congenital heart diseases, such as ToF.

CONCLUSIONS

Studies using animal models have demonstrated that the deficiency or disruption of a protein called "CITED2," which plays an important role in cardiac morphogenesis and its loss, results in the alteration of pluripotent, cardiac, and neural lineage differentiation, thereby disrupting the normal development of the heart and other tissues.

Long-term outcomes of tetralogy of Fallot repair: A 30-year experience with 960 patients

OBJECTIVE

This study evaluates the long-term results of tetralogy of Fallot repair and assesses the risk factors for adverse outcomes.

METHODS

This retrospective study included 960 patients who underwent transatrial transpulmonary tetralogy of Fallot repair between 1990 and 2020.

RESULTS

A transannular patch was placed in 722 patients, and pulmonary valve preservation was achieved in 233 patients. The median age at tetralogy of Fallot repair was 9.4 (interquartile range, 6.2-14.2) months. The median follow-up duration was 10.6 (interquartile range, 5.4-16.3) years. There were 8 early deaths (0.8%) and 20 late deaths (2.1%). Genetic syndrome and pulmonary valve annulus Z score less than -3 were risk factors for mortality. The survival was 97.7% (95% confidence interval, 96.4-98.5) and 94.5% (95% confidence interval, 90.9-96.7) at 10 and 30 years, respectively. Freedom from any reoperation was 86.4% (95% confidence interval, 83.6-88.7) and 65.4% (95% confidence interval, 59.8-70.4) at 10 and 20 years, respectively. Postoperative right ventricular outflow tract peak gradient of 25 mm Hg or greater correlated with reoperation. Propensity score-matched analysis demonstrated that freedom from pulmonary valve replacement at 15 years was higher in the pulmonary valve preservation group compared with the transannular patch group (98.2% vs 78.4%, P = .004). Freedom from reoperation for right ventricular outflow tract obstruction at 15 years was lower in the pulmonary valve preservation group compared with the transannular patch group (P = .006).

CONCLUSIONS

The long-term outcomes of tetralogy of Fallot repair are excellent. A postoperative right ventricular outflow tract peak gradient less than 25 mm Hg appears to be optimal to prevent reoperation. If the pulmonary valve size is suitable, pulmonary valve preservation reduces the risk of pulmonary valve replacement, yet increases the reoperation rate for right ventricular outflow tract obstruction.

Treating Tet Spells With Disopyramide in a 72-Year-Old Awaiting Primary Repair of Tetralogy of Fallot

An adult with unrepaired tetralogy of Fallot presented with frequent tet spells. Her course was complicated by severe cyanotic spells and tachycardia-bradycardia syndrome that limited beta blocker use to stabilize her spells. She markedly improved after disopyramide initiation and underwent successful tetralogy of Fallot repair with excellent functional outcome.

Evaluation and Management of Sudden Death Risk in Repaired Tetralogy of Fallot

Although substantial progress has been made to prevent sudden cardiac death in repaired tetralogy of Fallot patients, ventricular arrhythmia and sudden death continue to be major causes of morbidity and mortality in these patients. Greater survival in contemporary cohorts has been attributed to enhanced surgical techniques, more effective management of heart failure, and increased efforts in risk stratification and management of ventricular arrhythmias. More recently, our understanding of predictive risk factors has evolved into personalized risk prediction tools that rely on comprehensive demographic, imaging, functional, and electrophysiological data. However, the universal applicability of these different scoring systems is limited due to differences between study cohorts, types of anatomic repair, imaging modalities, and disease complexity. Noninvasive risk stratification is critical to identify those who may derive benefit from catheter ablation or cardioverter defibrillator implantation for primary prevention. Ultimately, assessment and risk stratification by a multidisciplinary team is crucial to analyze the various complex factors for every individual patient and discuss further options with patients and their families.

Comparison between the modified Blalock-Taussig shunt and right ventricular outflow tract stent in the palliative treatment for tetralogy of Fallot

OBJECTIVES

For patients with tetralogy of Fallot (TOF) who are not suitable candidates for primary corrective surgery or have a high surgical risk, transcatheter right ventricular outflow tract (RVOT) stent implantation is considered a safe and effective palliative intervention. This study aims to investigate the therapeutic outcomes of RVOT stent implantation in neonates and infants with TOF in comparison with the modified Blalock-Taussig shunt (mBTS) and to compare the impact of the 2 palliative interventions on arterial oxygen saturation and pulmonary artery development in pediatric patients.

METHODS

Clinical data of 32 patients with TOF admitted to the Second Xiangya Hospital of Central South University from March 2011 to March 2021 were retrospectively collected. The patients were divided into an mBTS group (undergoing mBTS, n=15) and a stent implantation group (undergoing RVOT stenting, n=17) according to the surgical procedures. The 2 groups were assessed and compared in the surgical-related arterial oxygen saturation, postoperative complication rate, mortality rate, and re-intervention rate. The development of the patients' main pulmonary artery, right pulmonary artery, and left pulmonary artery was assessed by z-scores according to echocardiographic results.

RESULTS

The children in the stent implantation group were younger and less weighed compared with the mBTS group (both P<0.05). Compared with the preoperative period, children in the stent implantation group had significantly higher arterial oxygen saturation [(75±17)% vs (96±3)%, P=0.026]; z-scores of pulmonary trunk [(-2.82±1.27) points vs (0.86±0.77) points, P=0.014], right pulmonary artery [(-1.88±0.59) points vs (-0.28±0.71) points, P=0.011], and left pulmonary artery [(-2.34±0.36) points vs (-1.67±0.36) points, P=0.036] were significantly increased. However, there were no significant differences in arterial oxygen saturation and pulmonary artery z-scores between pre- and post-mBTS procedures (all P>0.05).

CONCLUSIONS

RVOT stent would have good surgical outcomes used in TOF patients with low weight and severe comorbidities. It also leads to an higher postoperative oxygen saturation and better promotion of pulmonary artery growth with RVOT stent compared to mBTS.

The prevalence of abnormal spirometry in children with CHD

BACKGROUND

The burden of pulmonary disease in children with CHD remains under-recognised. Studies have examined children with single ventricle and two ventricle heart disease and documented a decreased forced vital capacity. Our study sought to further explore the pulmonary function of children with CHD.

METHODS

A retrospective review was performed of spirometry in CHD patients over a 3-year period. Spirometry data were corrected for size, age, and gender and analysed using z-scores.

RESULTS

The spirometry of 260 patients was analysed. About 31% had single ventricle (n = 80, 13.6 years (interquartile range 11.5-16.8)) and 69% had two ventricle circulation (n = 180, 14.4 years (interquartile range 12.0-17.3)). Single ventricle patients were found to have a lower median forced vital capacity z-score compared to two ventricle patients (p = 0.0133). The prevalence of an abnormal forced vital capacity was 41% in single ventricle patients and 29% in two ventricle patients. Two ventricle patients with tetralogy of Fallot and truncus arteriosus had similar low forced vital capacity comparable to single ventricle patients. The number of cardiac surgeries predicted an abnormal forced vital capacity in two ventricle patients except tetralogy of Fallot patients.

CONCLUSION

Pulmonary morbidity in patients with CHD is common with a decreased forced vital capacity noted in single ventricle and two ventricle patients. Forced vital capacity is lower in patients with single ventricle circulation; however, two ventricle patients with tetralogy of Fallot or truncus arteriosus have similar lung function in comparison to the single ventricle group. The number of surgical interventions was predictive of forced vital capacity z-score in some but not all two ventricle patients and not predictive in single ventricle patients suggesting a multifactorial to pulmonary disease in children with CHD.

A uniform strategy of primary repair of tetralogy of Fallot: Transventricular approach results in low reoperation rate in the first decade

OBJECTIVES

To review outcomes after a uniform strategy of transventricular repair of tetralogy of Fallot.

METHODS

A total of 244 consecutive patients underwent transventricular primary repair of tetralogy of Fallot from 2004 to 2019. Median age at operation was 71 days; 57 (23%) patients were premature; 57 (23%) patients had low birth weight (<2.5 kg), and 40 (16%) had genetic syndromes. The diameter of pulmonary valve annulus, right pulmonary artery (PA), and left PA were 6.0 ± 1.8 mm (z score, -1.7 ± 1.3), 4.3 ± 1.4 mm (z score, -0.9 ± 1.2) and 4.1 ± 1.5 mm (z score, -0.5 ± 1.3).

RESULTS

Three (1.2%) operative deaths were recorded. Ninety patients (37%) underwent transannular patching. Postoperative echocardiographic peak right ventricular outflow tract gradient decreased from 72 ± 27 mm Hg to 21 ± 16 mm Hg. Median intensive care unit and hospital stay were 3 and 7 days. The survival rate at 10 years was 94.6% ± 1.8%. Reintervention was required 86 times (55 catheter interventions) in 56 patients following tetralogy of Fallot repair. The freedom from all-cause reintervention rate at 10 years was 70.5% ± 3.6%. Cyanotic spells (hazard ratio, 2.14; 95% CI, 1.22-3.90; P < .01) and smaller pulmonary valve annulus z score (hazard ratio, 1.26; 95% CI, 1.01-1.59; P = .04) were associated with increasing risk of all reinterventions. Freedom from redo surgery for right ventricular outflow tract obstruction and right ventricular dilatation at 10 years were, respectively, 85.0% ± 3.1% and 98.7% ± 0.9%. Freedom from valve implantation was 96.7% ± 1.5% at 10 years.

CONCLUSIONS

A uniform strategy of primary repair of tetralogy of Fallot through a transventricular approach resulted in low reoperation rate in the first decade. The need of pulmonary valve implantation was limited to <4% at 10 years.

Right Ventricle and Epigenetics: A Systematic Review

There is an increasing recognition of the crucial role of the right ventricle (RV) in determining the functional status and prognosis in multiple conditions. In the past decade, the epigenetic regulation (DNA methylation, histone modification, and non-coding RNAs) of gene expression has been raised as a critical determinant of RV development, RV physiological function, and RV pathological dysfunction. We thus aimed to perform an up-to-date review of the literature, gathering knowledge on the epigenetic modifications associated with RV function/dysfunction. Therefore, we conducted a systematic review of studies assessing the contribution of epigenetic modifications to RV development and/or the progression of RV dysfunction regardless of the causal pathology. English literature published on PubMed, between the inception of the study and 1 January 2023, was evaluated. Two authors independently evaluated whether studies met eligibility criteria before study results were extracted. Amongst the 817 studies screened, 109 studies were included in this review, including 69 that used human samples (e.g., RV myocardium, blood). While 37 proposed an epigenetic-based therapeutic intervention to improve RV function, none involved a clinical trial and 70 are descriptive. Surprisingly, we observed a substantial discrepancy between studies investigating the expression (up or down) and/or the contribution of the same epigenetic modifications on RV function or development. This exhaustive review of the literature summarizes the relevant epigenetic studies focusing on RV in human or preclinical setting.

Patterns of Aortic Dilation in Tetralogy of Fallot: An Analysis of 100 Fetal Echocardiograms Compared With Matched Controls

Background Although aortic dilation is common in tetralogy of Fallot (TOF), its progression and risk of dissection are not well understood. The mechanism of dilation is primarily attributed to increased flow in utero; an alternative is unequal septation of the truncus arteriosus resulting in a larger aorta and inherently hypoplastic pulmonary artery (PA). If the latter is true, we hypothesize the aorta to PA ratio in TOF is stable throughout gestation, and sums of great artery dimensions are similar to controls. Methods and Results We performed a single-center retrospective study of fetuses with TOF (2014-2020) and matched controls. We compared sums of diameters, circumferences, and cross-sectional areas of the aorta and PA and evaluated the aorta to PA ratio across gestation in 2 TOF subtypes: pulmonary stenosis and atresia (TOF-PA). There were 100 echocardiograms with TOF (36% TOF-PA) with median gestational age of 31 weeks (interquartile range 26.5-34.4) and median maternal age of 34 years (interquartile range 30-37). There were no differences in sums of great artery dimensions between TOF-pulmonary stenosis and controls. In TOF-PA, sums were significantly lower than controls (P values <0.01). The aorta to PA ratio was stable throughout gestation (Pearson's r=0.08 [95% CI, -0.12 to 0.27], -0.06 [95% CI, -0.25 to 0.14]). Conclusions The aorta in fetal TOF is large but grows proportionally throughout gestation, with sums of great artery dimensions similar to controls. TOF-PA appears distinct from TOF-pulmonary stenosis (with smaller sums), warranting further investigation. In conclusion, our findings suggest an intrinsic developmental mechanism contributes to aortic dilation in TOF.

ACR Appropriateness Criteria® Congenital or Acquired Heart Disease

Pediatric heart disease is a large and diverse field with an overall prevalence estimated at 6 to 13 per 1,000 live births. This document discusses appropriateness of advanced imaging for a broad range of variants. Diseases covered include tetralogy of Fallot, transposition of great arteries, congenital or acquired pediatric coronary artery abnormality, single ventricle, aortopathy, anomalous pulmonary venous return, aortopathy and aortic coarctation, with indications for advanced imaging spanning the entire natural history of the disease in children and adults, including initial diagnosis, treatment planning, treatment monitoring, and early detection of complications. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Unrepaired tetralogy of Fallot in a 71 years old woman: A case report and review of the literature

Tetralogy of Fallot (ToF) is the most common cyanotic congenital heart disease (CHD) in infants. The four components that constitute ToF are an overriding aorta over the crest of the interventricular septum, obstruction in the right ventricular outflow tract, right ventricular hypertrophy, and a typically large non-restricted ventricular septal defect. ToF may also be associated with other extracardiac abnormalities, including patent ductus arteriosus or multiple aortopulmonary collateral arteries, which can impact the patient's survival. Patients with unoperated ToF rarely reach adulthood, and it is extremely rare to discover undiagnosed ToF in individuals over 60 years old. In this report, we describe an unusual case of a woman with unrepaired ToF who survived until the age of 71. She was fairly asymptomatic until the 7th decade of her life and complained only of dyspnea on exertion. The patient declined corrective cardiac surgery and preferred conservative management.

P-wave asystole after a tetralogy of Fallot correction surgery

A rarely seen arrhythmia is the p-wave asystole also mentioned ventricular asystole, ventricular standstill, or third-degree atrioventricular block with no ventricular escape rhythm. It is the result of the lack of impulse formation in ventricles (absence of idioventricular automaticity) or the failure of impulse transmission to ventricles (conduction disturbance)(1). As the name implies, the ventricles stop pumping, resulting in no effective cardiac output during the phenomenon. It is a potentially fatal rhythm disorder and need immediate diagnosis and treatment. We planned to present a case of p-wave asystole, which developed after tetralogy of Fallot total correction surgery.

Right ventricular outflow tract obstruction associated with neointimal tissue accumulation and distortion of the Harmony TPV25 stent frame: Potential mechanisms and treatment

BACKGROUND

The Harmony TPV25 transcatheter pulmonary valve (Medtronic Inc.) is constructed with a self-expanding stent frame comprising six zigged nitinol wires sewn together and covered with knitted polyester fabric, with flared inflow and outflow ends and a porcine pericardial valve sutured to the central portion of the device. It was approved for treatment of pulmonary regurgitation after prior right ventricular outflow tract repair in 2021. Early outcomes of this procedure have been excellent, but little is known about valve durability or ultimate mechanisms of dysfunction.

METHODS

We collected data on patients who underwent reintervention for TPV25 dysfunction and described findings related to distortion of the stent frame and tissue accumulation.

RESULTS

We describe six patients who underwent valve-in-valve implant for TPV25 obstruction (peak catheterization gradient peak 28-73 mmHg) 10-28 months after implant. In all cases, there was tissue accumulation within the inflow and valve-housing segments of the device and deformation of the self-expanding valve frame characterized by variable circumferential narrowing at the junction between the valve housing and the inflow and outflow portions of the device, with additional geometric changes in all segments. All six patients underwent valve-in-valve implant that results in a final peak gradient ≤10 mmHg and no regurgitation.

DISCUSSION

The occurrence of short-term Harmony TPV25 dysfunction in multiple patients with a similar appearance of frame distortion and tissue accumulation within the inflow and valve housing portions of the device suggests that this may be an important failure mechanism for this valve. Potential causes of the observed findings are discussed. It is possible to treat this mechanism of TPV25 dysfunction with valve-in-valve implant using balloon expandable transcatheter valves.