Into the Blue: First in Man Data on Diving Physiology in Fontan Patients.

Swimming and diving are popular recreational activities. As congenital heart disease, especially patients with univentricular hearts after Fontan palliation are thought to have reduced physiologic capacities for compensation of submersion-associated physiologic demands, current guidelines put restraints on this group of patients. Although these restrictions on doctoral advice place a significant burden on affected patients, it is especially interesting that these guideline recommendations are merely based on physiologic assumptions, i.e., expert consensus. A recent study by Paech et al. presented the first in vivo data on the effects of immersion in Fontan patients, stating no major adverse events in their study group as well as comparable physiologic adaption as reported in the literature for healthy people. Yet, submersion was not reflected in this study, and the current study therefore aimed to conduct a first study for the evaluation of the effects of submersion and apnea diving in Fontan patients. A control group of healthy adults as well as patients recruited from the Heart Center Leipzig, Department of pediatric cardiology underwent a standardized diving protocol including a static as well as dynamic apnea phase. Physiologic data were recorded. This study presents the first structured data on diving physiology in Fontan patients compared to healthy probands. There were no adverse events. The physiologic response to diving seems to be comparable between healthy probands and Fontan patients. Although, healthy probands did reach a much better performance, the basic mechanisms of physiologic adaption seem comparable.

Calf Muscle Oxygenation is Impaired and May Decline with Age in Young Patients with Total Cavopulmonary Connection.

Patients palliated with Total Cavopulmonary Connection have a lower muscle mass and a lower exercise capacity. We assessed calf muscle oxidative metabolism during and after heel raise exercise to exhaustion in young patients with TCPC compared to healthy peers. Near-infrared spectroscopy was used for measuring oxygen metabolism in the medial portion of the gastrocnemius muscle. Forty-three patients with TCPC, aged 6-18 years, were compared with 43 age and sex-matched healthy control subjects. Subgroups were formed to include children (6-12 years) and adolescents (13-18 years) to determine if these age groups influenced the results. During exercise, for the patients compared to controls there was a lower increase in deoxygenated hemoglobin (oxygen extraction) (5.13 ± 2.99au vs. 7.75 ± 4.15au, p = 0.001) and a slower rate of change in total hemoglobin (blood volume) (0.004 ± 0.015au vs 0.016 ± 0.01au, p = 0.001). Following exercise, patients exhibited a slower initial increase in tissue oxygenation saturation index (0.144 ± 0.11au vs 0.249 ± 0.226au, p = 0.007) and a longer half-time to maximum hyperemia (23.7 ± 11.4 s vs 16.8 ± 7.5 s, p = 0.001). On the subgroup level, the adolescents differed compared to healthy peers, whereas the children did not. Young patients with TCPC had impaired oxidative metabolism during exercise and required a longer time to recover. In that the differences were seen in the adolescent group and not in the children group may indicate a declining function with age.

Comparable long-term results of the extracardiac conduit total cavopulmonary connection in heterotaxy to non-heterotaxy patients.

BACKGROUND: Fontan operation in heterotaxy patients has been associated with high mortality. We studied whether adoption of the extracardiac conduit (EC) total cavopulmonary connection (TCPC) in heterotaxy demonstrated comparable results to non-heterotaxy population. METHODS: A retrospective medical record review of 35 consecutive patients with heterotaxy and 70 consecutive patients without heterotaxy syndrome who underwent EC TCPC between 2000 and 2018 was performed. RESULTS: In the 35 heterotaxy patients, 30 were right and 5 were left atrial isomerism. Anomalies of venous return included bilateral superior vena cava in 20 (57.1%), separated hepatic vein in 8 (22.9%), interrupted inferior vena cava in 3 (8.6%), total anomalous pulmonary venous return in 7 (20%), and partial in 2 patients (5.7%). All patients underwent EC TCPC under beating-heart cardiopulmonary bypass except in four patients (11.4%) cardioplegic arrest was needed for cardiac repair. The surgical mortality rate was lower in heterotaxy patients (0% vs. 5.7%; p = 0.299) but statistically not significant. The follow-up ranged from 2 months to 17.8 years (mean 9.4 ± 5.6 years). At 15 years, there was no significant difference between the heterotaxy and non-heterotaxy patients regarding the long-term survival (70% vs. 78.6%; p = 0.443), freedom from reoperation (81.9% vs. 96.5%; p = 0.057), and postoperative arrhythmia (17.1% vs. 7.1%; p = 0.174). CONCLUSIONS: EC TCPC can be performed in heterotaxy patients with comparable early and late results to the non-heterotaxy population. However, the late morbidities regarding the Fontan circulation needs careful follow-up.

In Memoriam: Professor Marc R. de Leval (April 16, 1941-June 26, 2022) - a tribute.

This manuscript is a personal tribute to Professor Marc de Leval from two of his colleagues: Professor Martin J. Elliott and Professor John E. Deanfield. As stated by the authors: "Marc's career history is presented in the accompanying eulogy from the current Heart & Lung Team at Great Ormond Street Hospital (GOSH), allowing us to highlight Marc's personal qualities that made him such an inspirational colleague. … Marc was, as we have said, the cardiologist's surgeon. He was also the surgeon's cardiologist, bridging the two disciplines and fusing the team. He was delighted by the advent of interventional cardiology and did not see it as a threat or competition, but instead, as appropriate for the well-being of his patients. He recognised how traumatic surgery could be for patients and their families and sought to avoid it whenever possible by alternative treatments. Marc will be remembered with love and admiration by his many patients and their families, whose lives he changed. His technical skill, energy, devotion, humour, intellect and influence will be sorely missed. May he rest in peace."

The Promoter of the Immune-Modulating Gene TIR-Containing Protein C of the Uropathogenic Escherichia coli Strain CFT073 Reacts to the Pathogen's Environment.

The TIR-containing protein C (TcpC) of the uropathogenic Escherichia coli strain CFT073 modulates innate immunity by interfering with the Toll-like receptor and NALP3 inflammasome signaling cascade. During a urinary tract infection the pathogen encounters epithelial and innate immune cells and replicates by several orders of magnitude. We therefore analyzed whether these cell types and also the density of the pathogen would induce the recently defined promoter of the CFT073 tcpC gene to, in time, dampen innate immune responses. Using reporter constructs we found that the uroepithelial cell line T24/83 and the monocytic cell line THP-1 induced the tcpC promoter. Differentiation of monocytic THP-1 cells to macrophages increased their potential to switch on the promoter. Cell-associated CFT073 displayed the highest promoter activity. Since potassium represents the most abundant intracellular ion and is secreted to induce the NLRP3 inflammasome, we tested its ability to activate the tcpC promoter. Potassium induced the promoter with high efficiency. Sodium, which is enriched in the renal cortex generating an antibacterial hypersalinity, also induced the tcpC promoter. Finally, the bacterial density modulated the tcpC promoter activity. In the search for promoter-regulating proteins, we found that the DNA-binding protein H-NS dampens the promoter activity. Taken together, different cell types and salts, present in the kidney, are able to induce the tcpC promoter and might explain the mechanism of TcpC induction during a kidney infection with uropathogenic E. coli strains.

The Fontan and the Sea: First-in-Man Data on Swimming and Diving Physiology in Fontan Patients.

While swimming represents a popular recreational activity, the immersion of the human body into the water requires a complex physiologic adaption of the whole cardiopulmonary and circulatory system. While this sport is regarded as beneficial, especially in cardiovascular patients, current guidelines hypothesized a possible hazardous effect of swimming and especially diving in patients with univentricular hearts after Fontan palliation. Yet, actual data to underline or contradict these assumptions are lacking. Therefore, this study aimed to conduct a first feasibility study for the evaluation of these effects on Fontan physiology and elucidate the gap of evidence currently preventing patients after Fontan palliation from being restricted from swimming or diving on doctoral advice. Patients recruited from the Heart Center Leipzig, Department of pediatric cardiology, underwent spiroergometry treadmill testing followed by a spiroergometry swimming stress test in a counter current pool. Physiologic data were recorded. A short apnea diving test was performed. The current study found similar physiologic reactions comparing treadmill and swimming exercise stress testing. Heart rate response and oxygen uptake were comparable on land and in the water. This study presents the first-in-man data on swimming and diving in Fontan patients. In this small study cohort of three Fontan patients, there were no adverse events triggered by swimming and breath-hold diving seen. Basically, the physiologic response to exercise was comparable on land and in the water.

Modeling Physiological Flow in Fontan Models With Four-Dimensional Flow Magnetic Resonance Imaging, Particle Image Velocimetry, and Arterial Spin Labeling.

The Fontan procedure is a successful palliation for single ventricle defect. Yet, a number of complications still occur in Fontan patients due to abnormal blood flow dynamics, necessitating improved flow analysis and treatment methods. Phase-contrast magnetic resonance imaging (MRI) has emerged as a suitable method for such flow analysis. However, limitations on altering physiological blood flow conditions in the patient while in the MRI bore inhibit experimental investigation of a variety of factors that contribute to impaired cardiovascular health in these patients. Furthermore, resolution and flow regime limitations in phase contrast (PC) MRI pose a challenge for accurate and consistent flow characterization. In this study, patient-specific physical models were created based on nine Fontan geometries and MRI experiments mimicking low- and high-flow conditions, as well as steady and pulsatile flow, were conducted. Additionally, a particle image velocimetry (PIV)-compatible Fontan model was created and flow was analyzed with PIV, arterial spin labeling (ASL), and four-dimensional (4D) flow MRI. Differences, though nonstatistically significant, were observed between flow conditions and between patient-specific models. Large between-model variation supported the need for further improvement for patient-specific modeling on each unique Fontan anatomical configuration. Furthermore, high-resolution PIV and flow-tracking ASL data provided flow information that was not obtainable with 4D flow MRI alone.

Echocardiographic characteristics in Fontan patients before the onset of protein-losing enteropathy or plastic bronchitis.

BACKGROUND: It was this study's objective to evaluate the echocardiographic characteristics and flow patterns in abdominal arteries of Fontan patients before the onset of protein-losing enteropathy (PLE) or plastic bronchitis (PB). DESIGN: In this retrospective cohort investigation, we examined 170 Fontan patients from 32 different centers who had undergone echocardiographic and Doppler ultrasound examinations between June 2006 and May 2013. Follow-up questionnaires were completed by 105 patients a median of 5.3 (1.5-8.5) years later to evaluate whether one of the complications had occurred since the examinations. RESULTS: A total of 91 patients never developed PLE or PB ("non-PLE/PB"); they were compared to 14 affected patients. Eight of the 14 patients had already been diagnosed with "present PLE/PB" when examined. Six "future PLE/PB" patients developed those complications later on and were identified on follow-up. The "future PLE/PB" patients presented significantly slower diastolic flow velocities in the celiac artery (0.1 (0.1-0.5) m/s vs 0.3 (0.1-1.0) m/s (P = .04) and in the superior mesenteric artery (0.0 (0.0-0.2) m/s vs 0.2 (0.0-0.6) m/s, P = .02) than the "non-PLE/PB" group. Median resistance indices in the celiac artery were significantly higher (0.9 (0.8-0.9) m/s vs 0.8 (0.6-0.9) m/s, (P = .01)) even before the onset of PLE or PB. CONCLUSION: An elevated flow resistance in the celiac artery may prevail in Fontan patients before the clinical manifestation of PLE or PB.

Use of a new low profile Occlutech PLD device for closure of Fontan fenestrations.

For some higher risk patients, fenestrations are still created in total cavopulmonary connection conduits completing the Fontan circulation for univentricular hearts. If these fenestrations remain patent and hemodynamics are favorable, they are closed to improve oxygenation and exercise tolerance and to decrease the risk of paradoxical emboli. Depending on the type of fenestration, different devices are used. Unfortunately, the search for the ideal device is still ongoing. We propose the first experience with the off-label use of the new Occlutech paravalvular leak device. This device offers the combination of a small delivery sheath size, high flexibility, less material, and a low profile. The low profile in particular could be an advantage in order to reduce the risk of thrombus formation in the low velocity flow environment of the Fontan circulation. © 2015 Wiley Periodicals, Inc.

Permanent trans-venous pacing in an extra-cardiac Fontan circulation.

AIMS: In patients with an extra-cardiac Fontan circulation, there is no direct access to the heart. The insertion of a permanent pacemaker requires surgery to insert epicardial pacing wires. We present the implantation of a permanent endocardial pacing lead from the superior vena cava (SVC) into the atrium via direct passage from the right pulmonary artery (RPA). METHODS AND RESULTS: A permanent pacing lead was passed directly from the SVC to the RPA and then into the atrial mass. Direct passage from the RPA (attached directly to the right SVC) into the atrial mass was achieved using a trans-septal puncture needle. CONCLUSION: This novel technique is an alternative to epicardial pacing in patients with an extra-cardiac Fontan circulation, thus avoiding the need for surgical intervention. It may also be applied to gain access to the atrial mass for arrhythmia ablation therapy.

Long-Term Serial Follow-Up of Pulmonary Artery Size and Wall Shear Stress in Fontan Patients.

Pulmonary arterial (PA) flow is abnormal after the Fontan operation and is marked by a lack of pulsatility. We assessed the effects of this abnormal flow on the size and function of the PA's in Fontan patients in long-term serial follow-up. Twenty-three Fontan patients with serial follow-up were included. Median age was 11.1 (9.5-16.0) years at baseline and 15.5 (12.5-22.7) years at follow-up. Median follow-up duration was 4.4 (4.0-5.8) years. Flow and size of the left pulmonary artery were determined using phase-contrast MRI. From this wall shear stress (WSS), distensibility and pulsatility were determined. A group of healthy peers was included for reference. Flow and pulsatility were significantly lower in patients than in controls (p < 0.001). Mean area was comparable in patients and controls, but distensibility was significantly higher in controls (p < 0.001). Mean and peak WSS were significantly lower in Fontan patients (p < 0.001). Between baseline and follow-up, there was a significant increase in normalized flow (15.1 (14.3-19.1) to 18.7 (14.0-22.6) ml/s/m(2), p = 0.023). Area, pulsatility, distensibility and WSS did not change, but there was a trend toward a lower mean WSS (p = 0.068). Multivariable regression analysis showed that flow, area and age were important predictors for WSS. WSS in Fontan patients is decreased compared to healthy controls and tends to decrease further with age. Pulsatility and distensibility are significantly lower compared to healthy controls. Pulmonary artery size, however, is not significantly different from healthy controls and long-term growth after Fontan operation is proportionate to body size.

Effects of landiolol on refractory tachyarrhythmia after total cavopulmonary connection: a retrospective, observational, cohort study.

The onset of tachyarrhythmia after the Fontan procedure (total cavopulmonary connection; TCPC) should be considered a medical emergency. Landiolol is an ultra-short-acting ß1-selective blocker whose effect on tachyarrhythmia after TCPC is unclear. We evaluated the efficacy and safety of landiolol for tachyarrhythmia after TCPC. Consecutive patients undergoing TCPC were enrolled from January 2007 to December 2011. Of 435 pediatric open heart surgeries, 28 patients underwent TCPC. Of the 28 patients, 13 were treated with landiolol for critical tachyarrhythmia. Excluding three patients who received landiolol during surgery, we investigated the remaining 10 patients and statistical analysis was performed without a 10-year-old patient as outlier. The median age was 4.08 years. The subjects comprised five patients with sinus tachycardia, four with junctional ectopic tachycardia and one with paroxysmal supraventricular tachycardia. The initial dose was 4.7 ± 2.3 µg/kg/min, without a loading dose. Landiolol reduced the heart rate from 151.8 ± 23.2 at the start to 132.9 ± 20.0 at 1 h and 126.1 ± 24.9 at 2 h (P < 0.01 and P < 0.01, respectively), without blood pressure decrease (P = 0.235). Landiolol was effective in treating critical tachyarrhythmia without hemodynamic deterioration. We believe that landiolol is a promising option for postoperative tachyarrhythmia after the Fontan procedure.

Quantification of ventricular stress in univentricular hearts during early childhood using age-independent zlog-NT-proBNP.

BACKGROUND: Children with univentricular hearts (UVH) undergo up to three palliative surgical procedures to achieve complete circulatory separation (Fontan circulation). As a marker of cardiac wall stress, NT-proBNP is a promising tool to assess systemic ventricular load in these patients. However, different reference intervals (RI) apply to each stage, as NT-proBNP is highly age-dependent. METHODS: Children undergoing systemic-to-pulmonary (SP) shunt placement (stage 1), bidirectional cavopulmonary shunt (BCPS, stage 2) or total cavopulmonary connection (TCPC, stage 3) between 2011 and 2021 with NT-proBNP measurement within 7 days before surgery were included. Furthermore, outpatients after TCPC with NT-proBNP measurement were enrolled. Biomarker levels were evaluated using its age-adjusted z-score ("zlog-NT-proBNP"; age-independent RI, -1.96 to +1.96), allowing comparison between different stages and revealing changes in systemic ventricular load independent of the marked physiological decline in RI with age. RESULTS: Overall, 289 children (227 before, 62 after TCPC) met the eligibility criteria. Median time between blood sampling and surgery (SP shunt/BCPS/TCPC) was 2 [1-3] days and 3.2 [2.0-4.5] years after TCPC. Age-adjusted zlog-NT-proBNP levels were 3.47 [2.79-3.93] in children with native UVH (before SP shunt), 3.10 [1.89-3.58] at stage 1 (before BCPS), 1.08 [0.51-1.88] at stage 2 (before TCPC), and 1.09 [0.72-1.75] at stage 3 (after TCPC/Fontan completion). Consequently, BCPS revealed the strongest decrease (median - 2.02 logarithmized standard deviations, p < 0.001). CONCLUSIONS: In children with UVH undergoing staged Fontan palliation, zlog-NT-proBNP is a highly promising tool for course assessment of systemic ventricular load, independent of the age-related decline in physiological NT-proBNP concentration.

Retrospective study of preoperative sildenafil in prolonged pleural effusion after Fontan.

Background: By rerouting the systemic venous return into the pulmonary circulation, the Fontan operation is perhaps the most effective palliative procedure in patients with complex congenital heart disease. The Fontan, however, still comes with several significant complications and morbidities, one of them being postoperative prolonged pleural effusion. In our center from 2017 to 2021, 10% of all our patients who underwent Fontan operation developed prolonged pleural effusion. With this study, we aimed to analyze the preoperative use of sildenafil for 6 months and its role in prolonged pleural effusion after the Fontan operation. Materials and Methods: In total, 158 patients were included in the analysis. The cohort was divided into patients who developed prolonged pleural effusion after Fontan surgery (n = 17) and those who did not (n = 141). We analyzed several risk factors and the history of sildenafil use in each group in the cohort. We found that patients who used sildenafil for at least 6 months prior to Fontan surgery versus those who did not use (n = 112 vs. n = 46) were found to be at lower risk of developing prolonged pleural effusion (odds ratio [OR]: 0.32 [confidence interval 95%: 0.11-0.88], P = 0.027). Conclusion: Preoperative administration of sildenafil for at least 6 months before Fontan might reduce the risk of postoperative prolonged pleural effusion.

Transport and Anaesthesia Consideration for Transcatheter Patent Ductus Arteriosus Closure in Premature Infants.

Transcatheter device closure of patent ductus arteriosus (PDA) in preterm infants has been proven to be a feasible and safe technique with promising results when compared to surgical ligation. However, managing transport and anaesthesia in extremely premature infants with haemodynamically significant PDA and limited reserves presents unique challenges. This review article focuses on the key considerations throughout the clinical pathway for the PDA device closure, including referral hospital consultation, patient selection, intra- and inter-hospital transport, and anaesthesia management. The key elements encompass comprehensive patient assessment, meticulous airway management, optimised ventilation strategies, precise thermoregulation, patient-tailored sedation protocols, vigilant haemodynamic monitoring, and safe transport measures throughout the pre-operative, intra-operative, and post-operative phases. A multidisciplinary approach enhances the chances of procedure success, improves patient outcomes, and minimises the risk of complications.

Possible effects of left pulmonary artery stenting in single ventricle patients on bronchial area, lung volume and lung function.

Background: Left pulmonary artery (LPA) stenting is often required in single ventricle (SV) patients. Due to their close anatomical relationship an LPA stent could potentially compress the left main bronchus (LMB). We assessed the impact of LPA stenting on bronchial size, pulmonary volumes, and lung function in a cohort of SV patients. Methods: Forty-nine patients underwent cardiovascular magnetic resonance (CMR) and 36 spirometry 11 (8-15) years after Fontan. All patients were free of respiratory symptoms. LPA stents were inserted in 17 (35%) patients at 8.8 (3.4-12.6) years. Area/shape of the main bronchi (n = 46) and lung volumes (n = 47) were calculated from CMR-ZTE images for each lung and transformed in right-to-left (r/l) ratio and indexed for BSA. The effect of early stent insertion (prior to stage III) was analyzed. Results: Patients with LPA stent had larger r/l ratio for main bronchus area (p < 0.001) and r/l ratio difference for lung volumes was slightly larger in patients with early stenting. A trend toward a deformation of LMB shape in patients with LPA stent and toward a higher prevalence of abnormal spirometry in patients with early stent implantation was observed. Conclusions: In this cohort of patients, early insertion of LPA stents seems to relate with smaller LMB sizes and a trend toward smaller left lung volume and higher prevalence of impaired lung function. Whether these findings are caused by the stent or, at least to a certain degree, present prior to the implantation needs to be verified.

Fluid Overload in Pediatric Univentricular Patients Undergoing Fontan Completion.

BACKGROUND: Fluid overload (FO) is known to occur frequently after pediatric cardiac surgery and is associated with morbidity and mortality. Fontan patients are at risk to develop FO due to their critical fluid balance. Furthermore, they need an adequate preload in order to maintain adequate cardiac output. This study aimed to identify FO in patients undergoing Fontan completion and the impact of FO on pediatric intensive care unit (PICU) length of stay (LOS) and cardiac events, defined as death, cardiac re-surgery or PICU re-hospitalization during follow-up. METHODS: In this retrospective single center study, the presence of FO was assessed in 43 consecutive children undergoing Fontan completion. RESULTS: Patients with more than 5% maximum FO had an extended PICU LOS (3.9 [2.9-6.9] vs. 1.9 [1.0-2.6] days; p < 0.001) and an increased length of mechanical ventilation (21 [9-121] vs. 6 [5-10] h; p = 0.001). Regression analysis demonstrated that an increase of 1% maximum FO was associated with a prolonged PICU LOS of 13% (95% CI 1.042-1.227; p = 0.004). Furthermore, patients with FO were at higher risk to develop cardiac events. CONCLUSIONS: FO is associated with short-term and long-term complications. Further studies are needed to determine the impact of FO on the outcome in this specific population.

Thoracic lymphatic anomalies in patients with univentricular hearts: correlation of morphologic findings in isotropic T2-weighted MRI with the outcome after fontan palliation.

Objectives: In this study we examined the correlation between the extent of thoracic lymphatic anomalies in patients after surgical palliation by total cavopulmonary connection (TCPC) and their outcome in terms of clinical and laboratory parameters. Materials and methods: We prospectively examined 33 patients after TCPC with an isotropic heavily T2-weighted MRI sequence on a 3.0 T scanner. Examinations were performed after a solid meal, slice thickness of 0.6 mm, TR of 2400 ms, TE of 692 ms, FoV of 460 mm, covering thoracic and abdominal regions. Findings of the lymphatic system were correlated with clinical and laboratory parameters obtained at the annual routine check-up. Results: Eight patients (group 1) showed type 4 lymphatic abnormalities. Twentyfive patients (group 2) presented less severe anomalies (type 1-3). In the treadmill CPET, group 2 reached step 7.0;6.0/8.0 vs. 6.0;3.5/6.8 in group 1 (p = 0.006*) and a distance of 775;638/854 m vs. 513;315/661 m (p = 0.006*). In the laboratory examinations, group 2 showed significantly lower levels of AST, ALT and stool calprotectin as compared to group 1. There were no significant differences in NT-pro-BNP, total protein, IgG, lymphocytes or platelets, but trends. A history of ascites showed 5/8 patients in group 1 vs. 4/25 patients in group 2 (p = 0.02*), PLE occurred in 4/8 patient in group 1 vs. 1/25 patients in group 2 (p = 0.008*). Conclusion: In the long-term follow-up after TCPC, patients with severe thoracic and cervical lymphatic abnormalities showed restrictions in exercise capacity, higher liver enzymes and an increased rate of symptoms of imminent Fontan-failure such as ascites and PLE.

Role of Cardiovascular Imaging in the Follow-Up of Patients with Fontan Circulation.

Since its first description in 1971, the Fontan procedure and its modifications have led to a substantial improvement in the survival rates of patients with a variety of types of complex Congenital Heart Disease (CHD) characterised by the presence of a single, dominant ventricle. However, despite the significant improvement of the prognosis over the years, Fontan patients are still exposed to several cardiovascular and systemic complications. It is, therefore, important to fully understand the pitfalls hidden behind a Fontan anatomy and the potential predictors of ventricular failure. Cardiovascular imaging plays a key role in this context, allowing for the early identification of complications with important prognostic implications. Echocardiography remains the first-line imaging modality for serial evaluation of Fontan patients. However, there is a growing role of cardiovascular magnetic resonance and cardiac computed tomography from pre-operative assessment to longitudinal follow-up. The aim of this paper will be to provide a comprehensive overview of the role, strengths, and weaknesses of each imaging modality in the assessment of congenital cardiac conditions palliated with the Fontan procedure.

The Epidemiology of Persons Living with Fontan in 2020 and Projections for 2030: Development of an Epidemiology Model Providing Multinational Estimates.

INTRODUCTION: Fontan surgery is a palliative procedure performed in children with a functionally univentricular heart. Improvements in surgical technique over the past 30 years have increased life expectancy in this rare population. However, the epidemiology of persons living with Fontan is poorly understood. This study aimed to estimate the 2020 and 2030 prevalence of persons living with a Fontan circulation in 11 countries across the US, Europe, Australia and New Zealand, by procedure type: [atriopulmonary connection (AP), lateral tunnel total cavopulmonary connection (LT-TCPC) or extracardiac total cavopulmonary connection (EC-TCPC)]; and age group: [children (< 12 years), adolescents (12-17 years), and adults (≥ 18 years old)] by building an epidemiologic model. METHODS: The annual number of Fontan surgeries by country in 2010-2020 were extracted from hospital or claims databases, via procedure codes. The epidemiology of persons living with Fontan was modelled by applying these surgery frequencies to mid-year populations from 1972 to 2020 and overlaying an uptake curve. A literature search identified: 30-day mortality rates, long-term survival, and median age at surgery. Averages of these estimates were inputted into the model to project prevalence in 2030. RESULTS: The number of persons living with Fontan in 2020 across the 11 countries was estimated to be 47,881 [66 people per million (ppm)], rising to 59,777 (79 ppm) by 2030. In 2020, this population was 55% adults, 17% adolescents and 28% children shifting to 64%, 13% and 23%, respectively, in 2030. Among all persons living with Fontan, 74%/18%/9% are estimated to have EC-TCPC/LT-TCPC/AP, respectively, in 2020, and 83%/14%/4% in 2030. CONCLUSIONS: According to this epidemiology model, the Fontan population is growing, partly driven by increased survival rates with the more recent LT-TCPC and EC-TCPC procedures (compared with AP). The 2020/2030 prevalence of persons living with Fontan is 66/79 ppm.