Effect of hemoglobin and oxygen saturation on adverse outcomes in children with tetralogy of fallot: a retrospective observational study.

BACKGROUND: Tetralogy of Fallot (TOF) is a common cyanotic congenital heart malformation that carries a high risk of right-to-left shunting. Anemia is characterized by decreased hemoglobin (Hb) levels that can affect tissue oxygen delivery and impact postoperative recovery in patients. Chronic hypoxia caused by right-to-left shunting of TOF could lead to compensatory increases in Hb to maintain systemic oxygen balance. This study aims to investigate whether preoperative Hb and blood oxygen saturation (SpO2) can predict adverse outcomes in children undergoing corrective surgery for TOF. METHODS: This retrospective study included patients under 18 years of age who underwent corrective surgery for TOF at Fuwai Hospital between January 2016 and December 2018. Adverse outcomes, including in-hospital death, extracorporeal membrane oxygenation implantation, ICU stay > 30 days, and severe complications, were considered as the primary outcome. Univariable and multivariable logistic analyses were performed to identify independent risk factors for adverse outcomes. Propensity score-matched (PSM) analysis was also conducted to minimize the confounding factors. RESULTS: A total of 596 children were included in the study, of which 64 (10.7%) experienced adverse outcomes. Hb*SpO2 < aaHb was identified as an independent risk factor for adverse outcomes (OR = 2.241, 95% CI = 1.276-3.934, P = 0.005) after univariable and multivariable logistic analyses. PSM analysis further confirmed the association between Hb*SpO2 < aaHb and adverse outcomes. Patients with Hb*SpO2 < aaHb had a significantly higher incidence of postoperative adverse outcomes, longer time of mechanical ventilation, and hospital stay, as well as higher in-hospital costs. CONCLUSIONS: Hb*SpO2 < aaHb is significantly associated with adverse outcomes in children undergoing corrective surgery for TOF. Clinicians can use this parameter to early identify high-risk children and optimize their postoperative management.

Tetralogy of fallot in addition to anomalous aortic origin of a coronary artery in a 1-year-old boy: a case report.

BACKGROUND: Anomalous aortic origin of a coronary artery (AAOCA) is a rare congenital heart disease, characterized by the coronary artery inappropriately originates from the aorta. It is usually classified according to the sinus where the coronary artery arises from, while anomalous origin of the right coronary being the most common type. CASE PRESENTATION: In this case report, we described a rare case of Tetralogy of Fallot (TOF) in a 1-year-old boy, who also had the anomalous right coronary artery that originated from the left coronary sinus without an intramural segment. Besides TOF repair, lateral pulmonary translocation was undertaken in order to avoid risks of myocardial ischemia. CONCLUSION: We successfully completed a one-stage operation consisting of TOF repair and pulmonary artery translocation in a 1-year-old boy. We advocated early operation of pulmonic translocation for AAOCA patients without an intramural segment instead of unroofing procedure.

Incidental detection of calcified left coronary artery pseudoaneurysm years after surgery for TOF.

We present images from computed tomography angiography in a 40-year-old female with a calcified pseudo-aneurysm in her left coronary artery, who had previously undergone repair of tetralogy of Fallot.

Proteomics analysis indicated the protein expression pattern related to the development of fetal conotruncal defects.

Abnormal development of embryonic conus arteriosus could lead to conotruncal defects in fetal heart, and increase the incidence of fetal congenital heart disease. Tetralogy of Fallot (TOF) is one of the most common forms of congenital heart disease. It may be helpful for us to solve this clinical problem through exploring the molecular mechanisms of development in embryonic congenital heart disease. Proteomics has attracted much attention in understanding the development of human diseases during the past decades. However, there is still little information about the relationship between protein expression pattern and TOF. In this study, we aimed to explore the potential linkage of proteomics and TOF development. Briefly, 121 differentially expressed proteins were identified from a TOF group, compared with a control group. The expression levels of 34 of these proteins were significantly different (>1.5 absolute fold change, p < 0.05) between the two groups. Gene ontology (GO) and pathway analysis showed that these proteins were mainly associated with carbon metabolism, biosynthesis of antibodies, positive regulation of transcription from RNA polymerase II promoter, nucleus, ATP binding, and so on. The ingenuity pathway analysis (IPA) results indicated that 435 of upstream regulators were identified of these differentially expressed proteins, which might be involved in the development of TOF. Data of string analysis showed the protein-protein interaction network among the differentially expressed proteins and regulators, which are related to TOF. In conclusion, our study explored the protein expression pattern of TOF, which might provide new insights into understanding the mechanism of TOF development and afford potential targets for TOF diagnosis and therapy.

Pregnancy outcomes among 31 patients with tetralogy of Fallot, a retrospective study.

BACKGROUND: Tetralogy of Fallot (TOF) is a severe type of congenital heart disease (CHD) and it confers substantial risk to mother and fetus for pregnant women. However, the outcome of pregnancy in women with TOF has not been well studied. METHODS: Women with TOF who have been seen and/or delivered at our tertiary-care hospital between April 2008 and January 2018 were retrospective reviewed. RESULTS: A total of 31 pregnant women with TOF were identified during ten-year period. Among these patients, cardiac defects remained uncorrected in 12 women and were surgically repaired in 19 women. The frequency of miscarriages, premature birth, and the percentage of neonates of small for gestational age (SGA) were greater in the uncorrected group than the surgically repaired group (16.67% vs 0, 50% vs 5.26, 41.67% vs 10.53% respectively). The neonatal mortality and fetal mortality were not observed in the surgically repaired group, but were observed in the uncorrected group [3.23% (1/31) and 6.45(2/31) respectively]. Furthermore, the obstetric and cardiac complications in the two groups were stratified and analyzed. CONCLUSIONS: Surgical correction of TOF is associated with improved maternal and perinatal outcome. However, pregnancy in women with uncorrected TOF was still seen and it was observed at a rate of 1.4/10,000 in our medical center during ten year period. The high degree of ventricular dilatation heart, high functional classifications, serious cardiac arrhythmias and pulmonary hypertension appeared to be associated with maternal and neonatal risks.

NRP1 haploinsufficiency predisposes to the development of Tetralogy of Fallot.

Tetralogy of Fallot (TOF) is the most common cyanotic congenital heart defect. It involves anatomical abnormalities that change the normal flow of blood through the heart resulting in low oxygenation. Although not all of the underlying causes of TOF are completely understood, the disease has been associated with varying genetic etiologies including chromosomal abnormalities and Mendelian disorders, but can also occur as an isolated defect. In this report, we describe a familial case of TOF associated with a 1.8 Mb deletion of chromosome 10p11. Among the three genes in the region one is Neuropilin1 (NRP1), a membrane co-receptor of VEGF that modulates vasculogenesis. Hemizygous levels of NRP1 resulted in a reduced expression at the transcriptional and protein levels in patient-derived cells. Reduction of NRP1 also lead to decreased function of its activity as a co-receptor in intermolecular VEGF signaling. These findings support that diminished levels of NRP1 contribute to the development of TOF, likely through its function in mediating VEGF signal and vasculogenesis.

Existence of mutations in the homeodomain-encoding region of NKX2.5 gene in Iranian patients with tetralogy of Fallot.

BACKGROUND: Tetralogy of Fallot (TOF), the most common cyanotic heart defect and one of the most common congenital heart diseases, occurs mostly sporadically and nonsyndromically. The underlying molecular genetic mechanism is not known. Therefore, the existence of mutations in the homeodomain-encoding region of NKX2.5 gene in Iranian patients with tetralogy of Fallot is evaluated. MATERIALS AND METHODS: In the present study, we analyzed the peripheral blood samples of27 patients in order to find any mutation in the 180 bp homeodomain-encoding region of NKX2.5 gene, which is known to be involved in heart development and diseases. DNA was extracted and all the samples were amplified by polymerase chain reaction (PCR) and sequenced. RESULTS: Twenty-seven patients were included in the study. Twenty-five of them were infants and children (6 days to 11 years of age), one was a teenager (14-years of age), and another was a 33-year-old man [mean ± standard deviation (SD): 5.80 ± 3.90 years]. Thirteen patents were males (mean ± SD: 6.587077 ± 5.02 years) and 14 were females (mean ± SD: 5.0726 ± 2.81 years). One synonymous variant, i.e., c.543G>A was identified in one patient. CONCLUSION: Mutations in the homeodomain-encoding region of NKX2.5 gene may not have an outstanding role in etiology of tetralogy of Fallot patients in Iran.

Identification of TBX5 mutations in a series of 94 patients with Tetralogy of Fallot.

Tetralogy of Fallot (TOF) (OMIM #187500) is the most frequent conotruncal congenital heart defect (CHD) with a range of intra- and extracardiac phenotypes. TBX5 is a transcription factor with well-defined roles in heart and forelimb development, and mutations in TBX5 are associated with Holt-Oram syndrome (HOS) (OMIM#142900). Here we report on the screening of 94 TOF patients for mutations in TBX5, NKX2.5 and GATA4 genes. We identified two heterozygous mutations in TBX5. One mutation was detected in a Moroccan patient with TOF, a large ostium secundum atrial septal defect and complete atrioventricular block, and features of HOS including bilateral triphalangeal thumbs and fifth finger clinodactyly. This patient carried a previously described de novo, stop codon mutation (p.R279X) located in exon 8 causing a premature truncated protein. In a second patient from Italy with TOF, ostium secundum atrial septal defect and progressive arrhythmic changes on ECG, we identified a maternally inherited novel mutation in exon 9, which caused a substitution of a serine with a leucine at amino acid position 372 (p.S372L, c.1115C>T). The mother's clinical evaluation demonstrated frequent ventricular extrasystoles and an atrial septal aneurysm. Physical examination and radiographs of the hands showed no apparent skeletal defects in either child or mother. Molecular evaluation of the p.S372L mutation demonstrated a gain-of-function phenotype. We also review the literature on the co-occurrence of TOF and HOS, highlighting its relevance. This is the first systematic screening for TBX5 mutations in TOF patients which detected mutations in two of 94 (2.1%) patients.

Transcatheter Pulmonary Valve in Congenital Heart Disease.

Over the last 2 decades, experience with transcatheter pulmonary valve replacement (TPVR) has grown significantly and has become an effective and reliable way of treating pulmonary valve regurgitation, right ventricular outflow (RVOT) obstruction, and dysfunctional bioprosthetic valves and conduits. With the introduction of self-expanding valves and prestents, dilated native RVOT can be addressed with the transcatheter approach. In this article, the authors review the current practices, technical challenges, and outcomes of TPVR.

Acute Cerebellitis and Obstructive Hydrocephalus: An Unseen Neurological Complication After Surgical Repair for Tetralogy of Fallot.

Acute cerebellitis with obstructive hydrocephalus post-Tetralogy of Fallot surgery is extremely rare but can present aggressively in pediatric cases. Early diagnosis is critical for prompt medical and surgical intervention. We report a fatal case in a 7-year-old boy post-surgery, where neurological symptoms rapidly progressed, leading to drowsiness and intermittent response to commands. Despite initial computed tomography scans showing no abnormality, subsequent scans revealed cerebellitis and hydrocephalus. Treatment with steroids, antibiotics, and cerebrospinal fluid drainage was unsuccessful, and the condition's etiology remained unclear despite negative serological tests and cultures. This highlights the challenge of diagnosing and treating acute cerebellitis, especially when no specific cause is found and when deterioration is swift. The role of opioids in pediatric patients and their potential association with neurosurgical complications is also discussed, prompting further inquiry into postoperative symptoms and opioid-related risks in susceptible individuals.

Myocardial tissue expression of mRNA and preoperative neutrophil-lymphocyte ratio in children undergoing congenital heart surgery.

Background: The neutrophil-lymphocyte ratio (NLR) is an easily accessible and inexpensive biomarker that has been shown to predict morbidity and mortality in congenital cardiac surgery. However, its regulatory mechanism remains unclear. This study aims to compare and correlate the tumor necrosis factor alpha (TNF-α), interleukin (IL)-1ß, IL-6, and IL-10 messenger RNAs (mRNAs) with the NLR in patients with tetralogy of Fallot (ToF) and ventricular septal defect (VSD). Methods: A prospective translational study was conducted on 10 children with ToF and 10 with VSD, aged between 1 and 24 months. The NLR was calculated from the blood count taken 24 hours before surgery. The expression of these mRNAs was analyzed in the myocardial tissue of the right atrium prior to cardiopulmonary bypass. Results: Patients with ToF exhibited a higher NLR [ToF 0.46 (interquartile range; IQR) 0.90; VSD 0.28 (IQR 0.17); P=0.02], longer mechanical ventilation time [ToF 24 h (IQR 93); VSD 5.5 h (IQR 8); P<0.001], increased use of vasoactive drugs [ToF 2 days (IQR 1.75); VSD 0 (IQR 1); P=0.01], and longer ICU [ToF 5.5 (IQR 1); VSD 2 (IQR 0.75); P=0.02] and hospital length of stays [ToF 18 days (IQR 17.5); VSD 8.5 days (IQR 2.5); P<0.001]. A negative correlation was found between NLR and oxygen saturation (SaO2) (r=-0.44; P=0.002). In terms of mRNA expression, the ToF group showed a lower expression of IL-10 mRNA (P=0.03). A positive correlation was observed between IL-10-mRNA and SaO2 (r=0.40; P=0.07), and a negative correlation with NLR (r=-0.27; P=0.14). Conclusions: Patients with ToF demonstrated a higher preoperative NLR and lower IL-10 mRNA expression by what appears to be a pro-inflammatory phenotype of cyanotic patients.

Severe pulmonary insufficiency caused by Fallot-type absent pulmonary valve syndrome: A rare reason for neonatal central cyanosis.

INTRODUCTION: Absent Pulmonary Valve Syndrome (APVS) is a rare birth defect where the pulmonary valve is missing or underdeveloped. APVS often occurs alongside Tetralogy of Fallot, (TOF) another heart defect. PRESENTATION OF CASE: A 33-year-old woman gave birth to a male infant with severe pulmonary stenosis (PS) and a large ventricular septal defect (VSD). The infant underwent surgery to close the VSD and resect the stenotic ring. Two years later, he remained asymptomatic with a closed VSD and no pulmonary valve gradient. DISCUSSION: Despite high mortality rates, long-term survival has improved with advancements in surgical repair. This case underscores the significance of early detection and personalized surgical strategies for complex congenital heart defects. CONCLUSION: Early identification of subtle symptoms is crucial for timely intervention, while individualized surgical strategies optimize outcomes. Further research is needed to understand the complex interplay of cardiac anomalies in APVS, particularly the absence of a patent ductus arteriosus in this case.

Total Correction for Tetralogy of Fallot in Patients Weighing Over 10 kg: Experiences and Follow-Up Outcomes.

Background Although the recommended time for total correction of tetralogy of Fallot (TOF) is during infancy, sometimes TOF cases present to healthcare setups after pre-school age, with some cases presenting even beyond adolescence in developing countries. The objective of this study was to assess patients with TOF weighing 10 kg and above who underwent definitive corrective surgical techniques such as transannular patch (TAP), valve-sparing right ventricular outflow tract (RVOT) pericardial patch augmentation, non-ventriculotomy infundibular resection for postoperative complications, hospital stay, and right ventricular (RV) dysfunction in the immediate postoperative period and subsequent outpatient department follow-ups. Methodology This comprehensive, retrospective cohort study included single-center data collected between January 16, 2018, and January 15, 2024. The study included 63 patients diagnosed with TOF weighing 10 kg and above, ensuring a robust and representative sample. Results Of the 119 patients who underwent total correction for TOF, 63 met the study's inclusion criteria of TOF weighing above 10 kg. Of the 63 patients, 55.6% were males, and 44.4% were females. The mean weight of the study participants was 33.4 kg. The mean age was 15.9 years. Of the 63 patients, 39 underwent TAP surgery, 18 underwent RVOT patch augmentation, and six underwent total correction by non-ventriculotomy infundibular resection. There was a significant difference between the type of surgery groups and RV dysfunction, with the TAP group showing a higher incidence of RV dysfunction, indicating a potential risk factor associated with this technique. Conclusions Although TAP has significant immediate postoperative complications compared to other techniques, its long-term follow-up suggests that long-term survival and quality of life, as measured by major adverse cardiac events such as heart failure, arrhythmias, and reoperation rates, are commensurable in adulthood. This indicates that despite the initial challenges, TAP can provide satisfactory outcomes in the long run.

Higher dose dobutamine stress MR imaging in repaired Tetralogy of Fallot: observer variance of volumetric assessment compared with normal volunteers.

PURPOSE: To investigate changes in image quality and observer variance between rest and higher-dose dobutamine stress MR imaging (DS-MR) in tetralogy of Fallot (TOF) patients and in a group of normal healthy volunteers using both axial and short axis orientation for cardiac volumetric assessment. MATERIALS AND METHODS: Eighteen adult patients (age 34 ± 13) with TOF and severe pulmonary regurgitation and 10 healthy volunteers underwent ventricular MR volumetry at baseline and during dobutamine infusion of 10 µg/kg/min and 20 µg/kg/min. Inter-observer and intra-observer agreement was calculated by coefficient of variance (COV). RESULTS: Inter-observer comparison showed good agreement for left ventricle (LV) and right ventricle (RV) end-diastolic volumes at rest and both stress levels in TOF patients (axial geometry) and in normal volunteers (short axis). During dobutamine stress, the COV in TOF patients increased for LV end-systolic volume (LV-ESV) with each level, suggesting less agreement between observers. In contrast, RV-ESV was much more comparable with a COV < 10 at each condition. All volumetric measurements in normal volunteers showed good inter-observer agreement. Excellent intra-observer agreement could be seen for all volumetric parameters with COV levels below 7. CONCLUSION: Volumetric assessment during DS-MR shows excellent inter-observer agreement, except for LV-ESV in the TOF patients at higher doses of dobutamine. The axial geometry appears to be reproducible for assessment of RV parameters, and could be considered superior to short axis imaging in patients with repaired TOF.

Adverse events after repair of tetralogy of Fallot: prediction models by machine learning of a retrospective cohort study in western China.

Background: The incidence of clinical adverse events after tetralogy of Fallot (TOF) repair remains high. This study was performed to explore risk factors for adverse events and develop a prediction model through machine learning (ML) to forecast the incidence of clinical adverse events after TOF repair. Methods: A total of 281 participants who were treated with cardiopulmonary bypass (CPB) at our hospital from January 2002 to January 2022 were included in the study. Risk factors for adverse events were explored by composite and comprehensive analyses. Five artificial intelligence (AI) models were used for ML to build prediction models and screen out the model with the best performance in predicting adverse events. Results: CPB time, differential pressure of the right ventricular outflow tract (RVOTDP or DP), and transannular patch repair were identified as the main risk factors for adverse events. The reference point for CPB time was 116.5 minutes and that for right ventricular (RV) outflow tract differential pressure was 70 mmHg. SPO2 was a protective factor, with a reference point of 88%. By integrating the results for the training and validation cohorts, we confirmed that, among all models, the logistic regression (LR) model and Gaussian Naive Bayes (GNB) model were stable, showing good discrimination, calibration and clinical practicability. The dynamic nomogram can be used as a predictive tool for clinical application. Conclusions: Differential pressure of the RV outflow tract, CPB time, and transannular patch repair are risk factors, and SPO2 is a protective factor for adverse events after complete TOF repair. In this study, models developed by ML were established to predict the incidence of adverse events.

Distinct non-contrast computerized tomography head findings in a patient with secondary polycythemia in rural Nepal: a captivating case report highlighting diagnostic challenges.

Introduction: Tetralogy of Fallot is a cyanotic congenital heart disease which if untreated leads to death by adulthood. In rare cases who survive this can lead to secondary polycythemia due to chronic hypoxia who can present with multiple indistinct symptoms leading to diagnostic dilemma. Case presentation: The authors present a rare case of secondary polycythemia diagnosed in early fifties with the unique non-contrast computerized tomography head findings who presented with a spectrum of long standing symptoms and a history of neurological manifestations. Clinical discussion: Patients diagnosed with polycythemia in adulthood can have a background of an untreated congenital heart disease, which can be complemented further by appropriate radiological investigations in a resource poor setting. Conclusion: Polycythemia secondary to an untreated congenital heart disease in the age beyond 50 is a rare occurrence. The presentation of these patients might present clinicians with a diagnostic challenge which can be mitigated with an appropriate knowledge of the peculiar non-contrast computerized tomography head findings.

Whole-exome sequencing revealed novel genetic alterations in patients with tetralogy of Fallot.

Background: The most prevalent cyanotic congenital heart disease (CHD) phenotype is tetralogy of Fallot (TOF). Rare genetic variations have been identified as significant risk factors for CHD. Thus, this research sought to identify the pathogenic variations and molecular etiologies of TOF. Methods: This study employed whole-exome sequencing (WES) and Sanger sequencing to identify pathogenic variations in DNA samples from patients with TOF. The pathogenicity of the variations was predicted using an in-silico approach. Results: We enrolled 17 patients with TOF in this study. Among these patients, 14 had mutations in TOF-related genes, including GJB2, TBX15, CTNS, SPINK1, GATA6, PRIMOL, GDF15, SLC17A9, AIFM1, FOXC2, KLF13, ABCA4, CPA6, FKBP10, ASPA, SBF1, HBA2, IGLL1, GNE, and KLHL10. We also gathered WES data from three participants without TOF, who comprised the control group, but no variations were found in the indicated genes. Further analysis showed that the patients with FKBP10 and GNE variants had more serious clinical symptoms. Sanger sequencing confirmed that the two variants were heterozygous in TOF patients. Conclusions: We identified several genetic variants associated with TOF and confirmed that FKBP10 and GNE variants were associated with TOF severity. The findings of this study help researchers and clinicians on genetic counseling with the verification of the potential of WES in detecting TOF and help implement early interventions for patients with TOF.

Right ventricular electromechanical dyssynchrony in adults with repaired Tetralogy of Fallot.

Background and purpose: Electromechanical dyssynchrony, manifested by right bundle branch block and regional wall mechanical dysfunction, contributes to inefficient RV function in repaired Tetralogy of Fallot (ToF). This study aims to evaluate the synchronicity of multiple RV walls using two-dimensional multi-plane echocardiography (2D-MPE) in order to augment current understanding of the mechanisms behind RV dyssynchrony. Methods: Sixty-nine adult ToF patients [aged 33 (23-45) years; 61% male] and twenty-five matched healthy controls underwent deformational analysis of the RV lateral, anterior, inferior and septal walls following 2D-MPE acquisitions. RV synchronicity was assessed by the intra-RV deformation delay between each basal RV wall and mid-septal segment in addition to mechanical dispersion calculated across four, six and eight segments (MD). Results: All RV wall-septum delays plus MD-4 and MD-6 indices were significantly greater in ToF patients compared to healthy controls (p < 0.001-0.03). In ToF patients, the lateral and anterior RV walls were last to reach peak deformation and anterior wall longitudinal strain was lower (p = 0.001). Post systolic shortening of at least one RV wall segment was identified in 19 (28%) ToF patients. Despite similar ECG characteristics, lateral and anterior wall-septum delays were significantly longer in patients with greater degrees of dyssynchrony (73 [37-108]ms vs. 37 [0-63]ms, p = 0.006; 91 [52-116]ms vs. 41 [1-69]ms, p = 0.013), although RV ejection fraction (RVEF) was not significantly lower. MD-4 and MD-8 indices displayed moderate negative associations with RVEF, strengthened by inclusion of lateral wall longitudinal strain (r = 0.64/0.65; p ≤0.01). Conclusion: RV dyssynchrony in ToF is characterised by electromechanical delays between the lateral, anterior and septal walls, with anterior wall dysfunction likely associated with surgical repair of the RV outflow tract. Prospectively, 2D-MPE may have an emerging role evaluating RV mechanical response to electrical resynchronisation therapy.

Development and validation of a predictive model for low cardiac output syndrome after surgical repair of tetralogy of Fallot.

Background: Low cardiac output syndrome (LCOS) remains a serious postoperative complication for children with tetralogy of Fallot (TOF), which often leads to increased morbidity and mortality. Early identification of LCOS and timely management are critical for better outcomes. This study aimed to develop a prediction model incorporating pre- and intraoperative characteristics for LCOS within 24 hours after surgical repair of TOF in children. Methods: The training dataset consisted of patients with TOF who underwent surgical repair in 2021, while the validation dataset consisted of patients in 2022. The univariable and multivariable logistic regression analyses were performed to recognize the risk factors of postoperative LCOS and a predictive model was established based on multivariable logistic regression analysis in the training dataset. Model predictive power was assessed using the area under the receiver operating characteristic curve (AUC). The calibration of the nomogram was evaluated and the Hosmer-Lemeshow test was used to assess the good fit. Decision curve analysis (DCA) was used to estimate the net benefits of the prediction model at different threshold probabilities. Results: In the multivariable logistic analysis, peripheral oxygen saturation, mean blood pressure, and central venous pressure were independent risk factors for postoperative LCOS. The AUC of the predictive model for postoperative LCOS was 0.84 (95% CI: 0.77-0.91) and 0.80 (95% CI: 0.70-0.90) in the training and validation datasets, respectively. The calibration curve for the probability of LCOS showed good agreement between the prediction by nomogram and actual observation both in the training and validation datasets. The Hosmer-Lemeshow test yielded nonsignificant statistics both in the training and validation datasets (P=0.69 and 0.54, respectively), indicating a good fit. The DCA revealed that more net benefits would be obtained by using the nomogram to predict LCOS than that achieved in either the treat-all-patient scheme or the treat-none scheme both in the training and validation datasets. Conclusions: This study is the first to incorporate pre- and intraoperative characteristics to develop a predictive model for LCOS after surgical repair of TOF in children. This model showed good discrimination, good fit and clinical benefits.

Midterm prognosis following total correction of tetralogy of fallot in adult patients.

Background: Tetralogy of Fallot is a common congenital heart disease characterized by cyanosis. The primary treatment approach involves corrective surgery typically performed within the first year of life to achieve complete resolution. However, certain patients may undergo surgery at an older age. This study seeks to assess the efficacy of surgery by examining the midterm outcomes of total correction of Tetralogy of Fallot when performed in older individuals. Methods: This interventional-longitudinal study focused on patients who underwent complete surgery to correct tetralogy of Fallot at an advanced age of over 15 years. All of the participants were referred to the Shahid Rajaei Heart and Vascular Center, which is a referral center for congenital heart diseases in Iran, between 2010 and 2020. The surgical procedures for these patients involved primary total correction of tetralogy of Fallot or surgery following by shunt implantation. Prior to the surgery, the necessary information was gathered from the patients' medical records. The patients were then monitored over a 5-year period, during which they received regular check-ups from cardiologist with fellowship in adult congenital heart disease. Results: A total of 94 participants were enrolled in the study, with an average age of 26.7 ± 9.6 years. Notably, the majority of the participants were male. The study reported a late mortality rate of 3.2%. Furthermore, 17 patients, constituting 18% of the cohort, underwent a secondary surgical procedure. This secondary surgery encompassed 14 cases of Pulmonary Valve Replacement (14.8%) and 3 cases of Ventricular Septal Defect repair (3.1%). Conclusion: While the optimal age for total correction of Tetralogy of Fallot is conventionally considered to be within the first year of life, this study demonstrated that surgical intervention performed at a later stage of life can yield favorable midterm prognoses. It is imperative to emphasize that individuals unable to undergo surgery at the ideal age due to a multitude of factors should not be deprived of the potential benefits associated with surgical intervention.