Fontan Failure Research Articles

Early Single Center Experience with an Ex Vivo Organ Care System in Pediatric Heart Transplantation

Pediatric heart transplantation (HTx) faces challenges such as limited donor availability and the need for complex reconstructions, particularly in patients with congenital anomalies. Ex vivo perfusion offers a promising approach to minimize graft ischemic time and potentially expand the donor pool. We report our single-center experience using the TransMedics Organ Care System (OCS) for ex vivo perfusion in pediatric HTx. From 2020-2024, eight pediatric patients received OCS-perfused donor hearts. Median recipient age was 13 years (range 9-18), and median weight was 58.8 kg (33.2-127.8). Indications for HTx included dilated cardiomyopathy (n=4), hypertrophic cardiomyopathy (n=1), graft vasculopathy (n=1), and Fontan failure (n=2). Median OCS time was 273 minutes (195-328), and recipient ischemic time was 85 minutes (64-139). Post-transplant, all patients had normal LV function at discharge. Over a median follow-up of 11.9 months, there were no deaths. These findings suggest that ex vivo perfusion is a valuable technique in pediatric HTx.

Outcomes and management of Haemoptysis in the Fontan population

Abstract Background Patients with a Fontan circulation for palliation of a univentricular congenital heart defect commonly possess pulmonary vascular abnormalities including arteriovenous malformations (AVM), aortopulmonary and venous-venous collaterals (1). These vessels are prone to haemorrhage which may result in life-threatening haemoptysis (2). This risk is increased with oral anticoagulant medication, given to reduce the risk of thromboembolism in Fontan patients (3). Management of these patients is difficult, and strategies vary across institutions. Purpose We aim to describe our experience with managing adult Fontan patients presenting with haemoptysis in a tertiary centre with a large Fontan cohort. Methods We retrospectively reviewed the records of 410 adult Fontan patients. Individuals admitted to our institution with an episode of haemoptysis were included. Details relating to anticoagulation regimens, interventions and mortality of patients were captured. Results From a cohort of 410 Fontan patients, 35 haemorrhagic events were observed in 11 patients (2.68%). The median age at initial haemoptysis was 24.5 years (range 19 to 43 years). 6 of the 11 patients were female (54.5%). Haemoptysis recurred in 8 of the 11 patients (72.7%). 2 out of 11 had a prior history of haemoptysis in childhood. All patients were administered with oral vitamin K antagonists at presentation. 24 of the 35 events were managed conservatively with IV fluids, anticoagulation reversal and tranexamic acid (66.7%). 11 events required catheter-based interventions, with coil and/or plug embolization of bleeding vessels. Prior to intervention, CT successfully identified potential bleeding sites in 10 of the 11 events (90.9%) but could not visualise all vessels that were subsequently embolized. The most common culprits for haemoptysis were aortopulmonary collaterals, followed by AVMs and venous-venous collaterals. In severe cases, more extensive management was required including transfusions, bronchoscopy, intubation, surgical exploration (1 patient) and pneumonectomy (1 patient). 3 patients died following recurrent severe haemoptysis (27.3%), and 2 patients died of subsequent Fontan failure and sudden cardiac death respectively. Total mortality of the cohort is 5 out of 11 (45.5%) with a median follow up of 10.75 years (range 3 days to 27 years). Conclusions Haemoptysis is a rare but potentially fatal complication in patients who have undergone a Fontan procedure. The variability in presentation of this condition mandates an individualised approach to management with involvement of a multidisciplinary team. There is a high rate of recurrence following haemoptysis and a comprehensive assessment of all potential bleeding sites is necessary. CT is a useful tool to help facilitate this and guide further management. Our policy is to close all potential sources of bleeding as CT and invasive angiography rarely identifies an active point of bleeding.

Incidence, pathophysiology, and treatment of failing Fontan after the total cavopulmonary connection.

Failing Fontan poses a significant clinical challenge. This study aims to improve patients' outcomes by comprehensively understanding the incidence, pathophysiology, risk factors, and treatment of failing Fontan after total cavopulmonary connection. We performed a retrospective analysis of patients who underwent total cavopulmonary connection at the German Heart Center Munich between 1994 and 2022. The onset of failing Fontan was defined as: protein-losing enteropathy, plastic bronchitis, NYHA class IV, NYHA class III for > one year, unscheduled hospital admissions for heart failure symptoms, and evaluation for heart transplantation. Among 634 patients, 76 patients presented with failing Fontan, and the incidence was 1.48 per 100 patient-years. Manifestations included protein-losing enteropathy (n = 34), hospital readmission (n = 28), NYHA III (n = 18), plastic bronchitis (n = 16), evaluation for heart transplantation (n = 14), and NYHA IV (n = 4). Risk factors for the onset of failing Fontan were dominant right ventricle (p = 0.010) and higher pulmonary artery pressure before total cavopulmonary connection (p = 0.004). A total of 72 interventions were performed in 59 patients, including balloon dilatation/stent implantation in the total cavopulmonary connection pathway (n = 49) and embolization of collaterals (n = 24). Heart transplantation was performed in four patients. The survival after the onset of Fontan failure was 77% at 10 years. Patients with failing Fontan revealed significantly higher zlog-NT-proBNP levels after onset compared to those without (p = 0.021). The incidence of Fontan failure was 1.5 per 100 patient years. Dominant right ventricle and higher pulmonary artery pressure before total cavopulmonary connection were significant risks for the onset of failing Fontan. Zlog-NT-proBNP is only a late marker of Fontan failure.

Long-term outcomes of direct total cavopulmonary connection versus extracardiac conduit in Fontan circulation

ObjectiveThe long-term outcomes of direct total cavopulmonary connection in Fontan circulation have not been reported yet. This study aimed to compare the long-term outcomes of the direct total cavopulmonary connection procedure with the extracardiac conduit procedure in patients undergoing the Fontan. MethodsFrom October 2004 to August 2021, 297 patients undergoing the Fontan operation by extracardiac conduit (n = 268) or direct total cavopulmonary connection (n = 29) procedure at our institution were retrospectively reviewed. The propensity score–matching method was used to match the extracardiac conduit and direct total cavopulmonary connection groups in a 1:2 ratio, yielding 23 patients in the direct total cavopulmonary connection group and 40 patients in the extracardiac conduit group. ResultsThe in-hospital morbidity and mortality were similar between the 2 groups in both prematched and matched cohorts (P > .05). The estimated transplantation-free survival at 10 years in the matched direct total cavopulmonary connection group was 89.7% ± 7.0%, in contrast to 92.8% ± 5.0% in the matched extracardiac conduit group (P = .55). The estimated 10-year estimated freedom from Fontan failure in the matched direct total cavopulmonary connection group was 85.2% ± 8.0%, also similar to the 85.9% ± 6.7% in the matched extracardiac conduit group (P = .72). The direct total cavopulmonary connection pathways at the follow-up were significantly larger than those before Fontan surgery (P < .05). ConclusionsThe direct total cavopulmonary connection procedure is a feasible and effective strategy for highly selected Fontan candidates who have well-developed pulmonary arteries of adequate length and size. This approach not only allows for the potential growth of direct total cavopulmonary connection pathways but also demonstrates noninferior short-term and long-term outcomes in contrast to the extracardiac conduit strategy.

Dapagliflozin Use in Children with Advanced Heart Failure Undergoing Heart Transplantation: A Matched Case-Control Study.

Dapagliflozin has been associated with euglycemic ketoacidosis in adults with diabetes contributing to poor outcomes when continued prior to surgery. It is unknown if preoperative use of dapagliflozin may lead to adverse events (AE) in nondiabetic children with advanced heart failure (HF) undergoing heart transplantation (HTx). We performed a single-center, matched case-control analysis of nondiabetic primary pediatric HTx recipients < 21years-old who underwent HTx and followed through postoperative day (POD) 3. Cases who received dapagliflozin leading up to HTx (n = 22) were matched by age and cardiac diagnosis to two historical controls who did not receive dapagliflozin (n = 44). Median age at HTx was 13.8years (range 0.36-20.7) and 48% were female. Cardiac diagnoses included cardiomyopathy (45%), Fontan failure (41%), and single ventricle status post stage I palliation (14%). Cases received median dapagliflozin dose of 0.17mg/kg once daily; therapy was stopped one day prior to HTx. There were no significant differences in blood glucose nadirs, arterial blood gas indices including nadirs of pH, bicarbonate, or peaks of arterial blood lactic acid POD0-3. Vasopressor, inotrope, and insulin infusion usage were not different. No patients were treated for severe hypoglycemia, euglycemic ketoacidosis, or urinary tract infections. There were no deaths. Length of stay in ICU and time from HTx to hospital discharge did not differ between cohorts. Use of dapagliflozin in children with advanced HF until HTx is not associated with AE in the immediate postoperative period nor increased length of hospitalization post-HTx. Potential cardiovascular benefits of dapagliflozin in patients awaiting HTx should be prioritized.

Mid-term results and late events after the Fontan operation: A single-center experience.

This study aimed to review our institutional experience with the Fontan operation, the adverse severe events we encountered during mid-term follow-up, and the associated risk factors. In the study, the medical records of 40 patients (22 males, 18 females) who underwent Fontan operation between August 1993 and August 2020 were retrospectively reviewed. The patients were followed up for at least six months. The Fontan operation was performed at a median age of 6.5 years (range, 3 to 22 years), and the mean follow-up time was 4.1±3.8 years (range, 0.5 to 17 years). The most frequently occurring defect was tricuspid atresia (45.0%). Fifteen (37.5%) patients experienced 24 late adverse events. Late complications and severe side effects, in order of frequency, were arrhythmia in eight (53.3%) patients, hypoxia in five (33.3%) patients, and ventricular dysfunction in three (20%) patients. While protein-losing enteropathy and mortality were each observed in two (13.3%) patients, Fontan failure, thromboembolic event, pulmonary arteriovenous fistulae, and ascites were each observed in one (6.6%) patient. When possible risk factors for late complications were examined, a statistical significance was not found. Life expectancy and quality of life of patients with Fontan circulation have increased with advances in surgical technique and increased management success. However, complications are not uncommon after the Fontan operation, and late events remain a significant problem. The results of our study indicate that in mid-term follow-up of patients who underwent Fontan surgery at our institution, although not statistically significant, those who underwent fenestration and those operated at a later age tended to experience more severe events and late complications.

Ventricular Morphology and Outcomes in Fontan Circulation without Hypoplastic Left Heart Syndrome: A Single-Center's Experience.

The impact of dominant ventricular morphology on Fontan patient outcomes remain controversial. This study evaluates long-term results of right ventricle (RV) dominance versus left ventricle (LV) dominance in Fontan circulation without hypoplastic left heart syndrome (HLHS). We retrospectively examined 323 Fontan operations from our center. To minimize pre- and intra-Fontan heterogeneity, 42 dominant RV patients were matched with 42 dominant LV patients using propensity score matching, allowing for a comparative analysis of outcomes between groups. The mean follow-up was 8.0 4.6 years for matched RV dominant and 6.5 4.7 years for matched LV dominant group (p 0.05), showing no significant difference. The cumulative incidence of moderate or greater atrioventricular valve regurgitation was also comparable between the two groups (p 0.05). Similarly, 10-year freedom from death or transplantation following the Fontan operation was 84% 7% in the matched dominant RV group, similar to 81% 7% in the matched dominant LV group (p 0.05). The 10-year freedom from Fontan failure was 78% 8% in the matched dominant RV group, also similar to 75% 8% in the matched dominant LV group (p 0.05). Multivariate analysis did not identify RV dominance as a risk factor for Fontan failure (p 0.05). In the pre- and intra-Fontan context, RV dominance demonstrated similar and comparable long-term outcomes compared to LV dominance in non-HLHS Fontan circulation.

Vectorcardiography signs of a failing Fontan: Heart rate, PR interval, RtQRSvm, QRSvm and SPQRS-T angle as noninvasive markers of late Fontan complications and mortality

BackgroundLimited data exists on interpreting vectorcardiography (VCG) parameters in the Fontan population. ObjectiveThe purpose of this study was to demonstrate the associations between ECG/VCG parameters and Fontan failure (FF). Methods/results107 patients with a Fontan operation after 1990 and without significant ventricular pacing were included. FF and Fontan survival (FS) groups were compared. The average follow-up after Fontan operation was 11.8 years ±7.1 years. 14 patients had FF (13.1%) which was defined as having protein-losing-enteropathy (1.9%), plastic bronchitis (2.8%), Fontan takedown (1.9%), heart transplant (5.6%), NYHA class III-IV (2.8%) or death (0.9%). A 12‑lead ECG at last follow up or prior to FF was assessed for heart rate, PR interval, QRS duration, Qtc and left/right sided precordial measures (P-wave, QRS and T-wave vector magnitudes, spatial P-R and QRS-T angles). Transthoracic echocardiogram evaluated atrioventricular valve regurgitation and ventricular dysfunction at FF or last follow up. A cox multivariate regression analysis adjusted for LV dominance, ventricular dysfunction, HR, PR, QTc, Pvm, QRSvm, SPQRST-angle, RtPvm, RtQRSvm and RtTvm. Ventricular dysfunction, increased heart rate and prolonged PR interval were significantly associated to FF at the multivariate analysis. ROC analysis and Kaplan-meier analysis revealed an increased total mortality associated with a heart rate > 93 bpm, PR interval > 155 mv, QRSvm >1.91 mV, RtQRSvm >1.8 mV and SPQRST angle >92.3 mV with p values <0.001 to 0.018. ConclusionWe demonstrate the importance of ECG/VCG monitoring in the Fontan population and suggest specific indicators of late complications and mortality.

The long-term effects of the fenestration in patients with extracardiac Fontan circulation-a multicenter Korean cohort study based on national Fontan registry.

The long-term effects of fenestration in patients with Fontan circulation remain unclear. We aim to evaluate the fenestration impact on early and late outcomes in patients with extracardiac Fontan (ECF) using a propensity score matching analysis. We performed an extensive retrospective multicenter clinical data review of the Korean Fontan registry and included 1,233 patients with surgical ECF (779 fenestrated, 454 non-fenestrated). Demographics, baseline, and follow-up data were collected and comprehensively analyzed. Patients were divided into two groups according to the baseline presence or absence of surgical fenestration. Subsequently, patients were sub-divided according to the fenestration status at the last follow-up. Propensity-score matching was performed to account for collected data between the 2 groups using a multistep approach. The primary outcomes were survival and freedom from Fontan failure (FFF). We also looked at postoperative hemodynamics, cardiopulmonary exercise test results, oxygen saturations, and functional status. After propensity-score matching (454 matched pairs), there was no difference in survival or FFF between the 2 groups. However, ECF patients with baseline fenestration had significantly lower oxygen saturation (p = 0.001) and lower functional status (p < 0.001). Patients with fenestration had significantly longer bypass times, higher postoperative central venous pressure, higher postoperative left atrial pressure, and less prolonged pleural effusion in the early postoperative period. The propensity score matching according to the fenestration status at the last follow-up (148 matched pairs) showed that patients with a persistent fenestration had significantly lower oxygen saturation levels (p < 0.001). However there were no intergroup differences in the functional status, survival and FFF. Our results showed no long-term benefits of the Fenestration in terms of survival and FFF. Patients with persistent fenestration showed oxygen desaturation but no difference in exercise intolerance was shown between the 2 groups.

Association of patient-level characteristics with long-term outcomes after Fontan palliation: Rationale, design, and baseline characteristics of the Pediatric Cardiac Care Consortium Fontan cohort study

BackgroundThe Fontan operation is used to palliate single ventricle congenital heart defects (CHD) but poses significant morbidity and mortality risks. We present the design, planned analyses, and rationale for a long-term Fontan cohort study aiming to examine the association of patient characteristics at the time of Fontan with post-Fontan morbidity and mortality. Methods and ResultsWe used the Pediatric Cardiac Care Consortium (PCCC), a US-based, multicenter registry of pediatric cardiac surgeries to identify patients who underwent the Fontan procedure for single ventricle CHD between 1 and 21 years of age. The primary outcomes are in-hospital Fontan failure (death or takedown) and post-discharge mortality through 2022. A total of 1461 (males 62.1%) patients met eligibility criteria and were included in the analytical cohort. The median age at Fontan evaluation was 3.1 years (IQR: 2.4–4.3). While 95 patients experienced in-hospital Fontan failure (78 deaths and 17 Fontan takedown), 1366 (93.5%) survived to discharge with Fontan physiology and formed the long-term analysis cohort. Over a median follow-up of 21.2 years (IQR: 18.4-24.5) 184 post-discharge deaths occurred. Thirty-year post Fontan survival was 75.0% (95% CI: 72.3%-77.8%) for all Fontan types with higher rates for current techniques such as lateral tunnel and extracardiac conduit 77.1% (95% CI: 73.5-80.8). ConclusionThe PCCC Fontan study aims to identify predictors for post-Fontan morbidity and mortality, enabling risk- stratification and informing surveillance practices. Additionally, the study may guide therapeutic interventions aiming to optimize hemodynamics and enhance Fontan longevity for individual patients.

Patient-specific closed-loop model of the fontan circulation: Calibration and validation

The Fontan circulation, designed for managing patients with a single functional ventricle, presents challenges in long-term outcomes. Computational methods offer potential solutions, yet their application in cardiology practice remains largely unexplored. Our aim was to assess the ability of a patient-specific, closed-loop, reduced-order blood flow model to simulate pulsatile blood flow in the Fontan circulation. Using one-dimensional models, we simulated the aorta, superior and inferior venae cavae, and right and left pulmonary arteries, while lumping heart chambers and remaining vessels into zero-dimensional models. The model was calibrated with patient-specific haemodynamic data from combined cardiac catheterisation and magnetic resonance exams, using a novel physics-based stepwise methodology involving simpler open-loop models. Testing on a 10-year-old, anesthetised patient, demonstrated the model's capability to replicate pulsatile pressure and flow in the larger vessels and ventricular pressure. Average relative errors in mean pressure and flow were 2.9 % and 3.6 %, with average relative point-to-point errors (RPPE) in pressure and flow at 5.2 % and 16.0 %. Comparing simulation results to measurements, mean aortic pressure and flow values were 50.7 vs. 50.4 mmHg and 41.6 vs. 41.9 ml/s, respectively, while ventricular pressure values were 28.7 vs. 27.4 mmHg. The model accurately described time-varying ventricular volume with a RPPE of 2.9 %, with mean, minimum, and maximum ventricular volume values for simulation results vs. measurements at 59.2 vs. 58.2 ml, 38.0 vs. 37.6 ml, and 76.0 vs. 74.4 ml, respectively. It provided physiologically realistic predictions of haemodynamic changes from pulmonary vasodilation and atrial fenestration opening. The new model and calibration methodology are freely available, offering a platform to virtually investigate the Fontan circulation's response to clinical interventions and explore potential mechanisms of Fontan failure. Future efforts will concentrate on broadening the model's applicability to a wider range of patient populations and clinical scenarios, as well as testing its effectiveness.

Anesthetic challenges in patients with multicompartmental lymphatic failure after Fontan palliation undergoing transcatheter thoracic duct decompression.

Lymphatic flow abnormalities are central to the development of protein losing enteropathy, plastic bronchitis, ascites and pleural effusions in patients palliated to the Fontan circulation. These complications can occur in isolation or multicompartmental (two or more). The treatment of multicompartmental lymphatic failure aims at improving thoracic duct drainage. Re-routing the innominate vein to the pulmonary venous atrium decompresses the thoracic duct, as atrial pressure is lower than systemic venous pressure in Fontan circulation. Transcatheter thoracic duct decompression is a new minimally invasive procedure that involves placing covered stents from the innominate vein to the atrium. Patients undergoing this procedure require multiple general anesthetics, presenting challenges in managing the sequelae of disordered lymphatic flow superimposed on Fontan physiology. We reviewed the first 20 patients at the Center for Lymphatic Imaging and Intervention at a tertiary care children's hospital presenting for transcatheter thoracic duct decompression between March 2018 and February 2023. The patients ranged in age from 3 to 26 years. The majority had failed prior catheter-based lymphatic intervention, including selective embolization of abnormal lympho-intestinal and lympho-bronchial connections to treat lymphatic failure in a single compartment. Fourteen had failure in three lymphatic compartments. Patients were functionally impaired (ASA 3-5) with significant comorbidities. Concurrent with thoracic duct decompression, three patients required fenestration closure for the resultant decrease in oxygen saturation. Ten patients had improvement in symptoms, seven had no changes and three have limited follow up. Five (25%) of these patients were deceased as of January 2024 due to non-lymphatic complications from Fontan failure.

(1390) - Pioneering Successful Transplantation with a Ventricular Assist Device in Fontan Failure: The First Experience in South Korea

(1390) - Pioneering Successful Transplantation with a Ventricular Assist Device in Fontan Failure: The First Experience in South Korea

The Prevalence of Scoliosis after Fontan Circulation Surgery Followed-Up to Adolescence.

The advancement of surgical techniques and perioperative management for congenital heart disease (CHD) has increased life expectancy. The surgical creation of the Fontan circulation maintains pulmonary blood flow without relying on an effective pump from the abnormal heart, relying on peripheral vascular resistance to maintain effective flow through the lungs. Unfortunately, this delicate mechanism is compromised when scoliosis restricts ventilation, leading to Fontan failure and a poor prognosis for life. This report describes the prevalence of scoliosis with Fontan completion surgery and the role of screening and surgical correction. Ninety-six consecutive Japanese patients undergoing Fontan completion surgery for CHD between 2000 and 2017 were identified in our institutional records. The inclusion criterion was at least 7 years of follow-up after Fontan completion surgery, while the exclusion criteria were congenital, syndromic, and neuromuscular scoliosis. Radiographic and clinical parameters, including cardio-thoracic ratio (CTR) for cardiomegaly and cyanosis saturation, were compared between with and without scoliosis. There were 23 and 40 patients in the scoliosis and no scoliosis groups, respectively. The mean age at the final follow-up was 18.5 and 16.7 years in the scoliosis and no scoliosis groups, respectively (p=0.02). Mean CTR was 43.7% and 39.4% in the scoliosis and no scoliosis groups (p=0.016), and the mean saturation in room air at the final follow-up was 88.8% and 93.2%, respectively (p=0.036). There were no significant differences to clarify the risk factors with multivariate logistic regression analysis. The prevalence of scoliosis with Fontan completion surgery was 36.5%. Screening for scoliosis is important for children with Fontan circulation surgery as part of their routine follow-up at least until they reach adolescence.

Dielectric elastomer actuator-based valveless pump as Fontan failure assist device: introduction and preliminary study.

Fontan failure refers to a condition in which the Fontan circulation, a surgical procedure used to treat certain congenital heart defects, becomes insufficient, leading to compromised cardiac function and potential complications. This in vitro study therefore investigates the feasibility of bladeless impedance-driven cavopulmonary assist device via dielectric elastomer actuator (DEA) as a means to address Fontan failure. A cavopulmonary assist device, constructed using DEA technologies and employing the impedance pump concept, is subjected to in vitro testing within a closed-loop setup. This study aims to assess the device's functionality and performance under controlled conditions, providing valuable insights into its potential application as a cavopulmonary assistive technology. The DEA-based pump, measuring 50 mm in length and 30 mm in diameter, is capable of achieving substantial flow rates within a closed-loop setup, reaching up to 1.20 l/min at an activation frequency of 4 Hz. It also provides a broad range of working internal pressures (<10 to >20 mmHg). Lastly, the properties of the flow (direction, magnitude, etc.) can be controlled by adjusting the input signal parameters (frequency, amplitude, etc.). In summary, the results suggest that the valveless impedance-driven pump utilizing DEA technology is promising in the context of cavopulmonary assist devices. Further research and development in this area may lead to innovative and potentially more effective solutions for assisting the right heart, ultimately benefiting patients with heart-related health issues overall, with a particular focus on those experiencing Fontan failure.

Delivering Serious News in Pediatric Cardiology-A Pilot Program.

Pediatric cardiology fellows receive limited training on delivering serious news. This is a teachable skill through simulation-based communication. While studies have shown the use of communication courses in pediatrics, there have been none in pediatric cardiology. Pediatric cardiologists recognize the importance of good communication and desire further development of these skills. Based on an internal needs assessment, three cases were developed; fetal hypoplastic left heart syndrome, teenager with new hypertrophic cardiomyopathy, and young-adult with Fontan failure. A 4-h simulation course using evidence-based methods to teach delivering serious news was designed, consisting of a didactic session, case demonstration and small group case-based encounters with simulated patients. Trainees completed standardized pre/post-course surveys to assess perception of skill and preparedness. Paired survey responses were compared. Six pediatric cardiology fellows participated. Only 33% had received formal training in delivering serious news and 17% in techniques of responding to patient's emotions. The proportion of participants who felt good about their ability to deliver serious news and deal with a family's emotions increased from 0 to 83%. The proportion of participants who felt prepared to provide serious news about a patient's illness increased from 17 to 67%. Given the small number of participants, results were not statistically significant. All participants felt that the course was valuable in improving communication skills. A formal communication course increased perception of skill and preparedness among trainees. We provide an evidence-based framework and clinical cases for delivering serious news in pediatric cardiology, which is generalizable to other training programs.

Impact of the Rudimentary Chamber on Outcomes in Fontan Patients.

Background: We sought to evaluate the influence of the rudimentary ventricle on long-term outcomes after the Fontan operation, focusing on exercise capacity and cardiac performance. Methods: Between 1995 and 2021, 290 patients underwent a total cavopulmonary connection. "Two-ventricle" Fontan circulation was defined as a rudimentary ventricle >30% of the dominant ventricle or >50% of its predicted normal value. This cohort was compared with patients with single-ventricle Fontan circulation. The primary endpoint was Fontan failure, and the secondary endpoints were VO2 and cardiac catheterization data at ten years postoperatively. Results: The median follow-up after the Fontan operation was 7.9 years (interquartile range: 1.9-13.9). No significant difference was found in Fontan failure-free survival between the "two-ventricle" Fontan circulation group and the single-ventricle Fontan circulation group (83/91, 93% vs 156/199, 78%), respectively at 20 years; P = .11). No significant difference was found in VO2 or cardiac performance except cardiac index, with 2.9 (2.3-4.8) versus 2.5 (2.3-4.3) L/min/m2 (P = .047). Fifty-one patients in the "two-ventricle" Fontan circulation group were followed up for over ten years after the Fontan operation. In the subgroup analysis of this cohort, the rudimentary ventricular end-diastolic volume/dominant ventricular end-diastolic volume ratio showed a significant positive correlation with dominant ventricular end-diastolic pressure (r = 0.58 [95% CI 0.35-0.74], P = .002) and a significant negative correlation with VO2 (r = -0.61 [95% CI -0.80 to -0.28], P = .001). Conclusions: The rudimentary ventricle was not significantly associated with any clinical disadvantages regarding Fontan failure. However, a large rudimentary ventricle was significantly associated with higher end-diastolic pressure and lower exercise capacity.

Lymphopenia in the Adult Population With Fontan Physiology: A Potential New Marker for Disease Assessment

BackgroundPatients with complex congenital heart disease and Fontan palliation frequently develop extracardiac disease, including hematologic abnormalities, such as lymphopenia. However, the clinical implications of this finding are poorly understood and are therefore the topic of this investigation. MethodsPatients with Fontan physiology in our centre (1999-2018) were evaluated for the presence and impact of lymphopenia. The cohort was divided into a group with lymphopenia (L) (2 consecutive absolute lymphocyte counts ≤ 1∗103 K/ μL) and a group who had never had lymphopenia (NL). Clinical characteristics and hospital admissions (762 patient-years) were evaluated. ResultsIn 62 adult patients with Fontan physiology (aged 34 ± 9 years; 32 women [52%]), the patients who developed lymphopenia earliest did so 8 years after Fontan completion, with up to 60% of patients developing lymphopenia by 30 years. Lymphopenia was found to be associated with portal hypertension (varices, ascites, splenomegaly, and thrombocytopenia [VAST] score)—NL: 0 (0-2) vs L: 2 (0-4), P < 0.0001). A total of 76 heart failure and 81 arrhythmia-associated admissions occurred per 1000 patient-years. At 40 years post-Fontan, the probability of a heart failure admission was higher in the L group (L: 51 [86%] vs NL: 8 [14%], P < 0.01). ConclusionsAdult patients with Fontan physiology and lymphopenia demonstrated portal hypertension and lymphatic dysfunction more commonly, perhaps suggesting that this may be a marker of Fontan congestion and early Fontan failure. Further investigation into the relationship between lymphopenia, clinical outcomes, and Fontan function is needed.

Pacemaker-Related Factors and Outcomes of Fontan Patients - Impact of Paced QRS Duration.

Permanent pacemaker (PPM) implantation has been identified as a risk factor for morbidity and mortality after Fontan operation. This study investigated the factors associated with outcomes in patients with Fontan physiology who underwent PPM implantation. We retrospectively reviewed 508 patients who underwent Fontan surgery at Asan Medical Center between September 1992 and August 2022. Of these patients, 37 (7.3%) received PPM implantation. Five patients were excluded, leaving 32 patients, of whom 11 were categorized into the poor outcome group. Poor outcomes comprised death, heart transplantation, and "Fontan failure". Clinical, Fontan procedure-related, and PPM-related factors were compared between the poor and good outcome groups. Ventricular morphology, Fontan procedure-associated factors, pacing mode, high ventricular pacing rate, and time from first arrhythmia to PPM implantation did not differ significantly between the 2 groups. However, the poor outcome group exhibited a significantly longer mean paced QRS duration (P=0.044). Receiver operating characteristic curve analysis revealed a paced QRS duration cut-off value of 153 ms with an area under the curve of 0.73 (P=0.035). A longer paced QRS duration was associated with poor outcomes, indicating its potential to predict adverse outcomes among Fontan patients.

In vitro investigation of axial mechanical support devices implanted in the novel convergent cavopulmonary connection Fontan.

The 2 opposing inflows and 2 outflows in a total cavopulmonary connection make mechanical circulatory support (MCS) extremely challenging. We have previously reported a novel convergent cavopulmonary connection (CCPC) Fontan design that improves baseline characteristics and provides a single inflow and outflow, thus simplifying MCS. This study aims to assess the feasibility of MCS of this novel configuration using axial flow pumps in an in vitro benchtop model. Three-dimensional segmentations of 12 single-ventricle patients (body surface area 0.5-1.75 m2) were generated from cardiovascular magnetic resonance images. The CCPC models were designed by connecting the inferior vena cava and superior vena cava to a shared conduit ascending to the pulmonary arteries, optimized in silico. The 12 total cavopulmonary connection and their corresponding CCPC models underwent in vitro benchtop characterization. Two MCS devices were used, the Impella RP® and the PediPump. MCS successfully and symmetrically reduced the pressure in both vena cavae by >20 mmHg. The devices improved the hepatic flow distribution balance of all CCPC models (Impella RP®P = 0.045, PediPump P = 0.055). The CCPC Fontan design provides a feasible MCS solution for a failing Fontan by balancing hepatic flow distribution and symmetrically decompressing the central venous pressure. Cardiac index may also improve with MCS. Additional studies are needed to evaluate this concept for managing Fontan failure.