Liver fibrosis detected by diffusion-weighted magnetic resonance imaging and its functional correlates in Fontan patients.

OBJECTIVES: The evaluation of Fontan-associated liver disease is often challenging. Diffusion-weighted magnetic resonance imaging can detect hepatic fibrosis from capillary perfusion and diffusion abnormalities from extracellular matrix accumulation. This study investigated its role in the evaluation of liver disease in Fontan patients and explored possible diagnostic methods for early detection of advanced liver fibrosis. METHODS: Stable adult Fontan patients who could safely be examined with magnetic resonance imaging were enrolled, and blood biomarkers, transient elastography were also examined. RESULTS: Forty-six patients received diffusion-weighted imaging; and 58.7% were diagnosed with advanced liver fibrosis (severe liver fibrosis, 37.0%, and cirrhosis 21.7%). Two parameters of hepatic dysfunction, platelet counts (Spearman's ρ: -0.456, P = 0.001) and cholesterol levels (Spearman's ρ: -0.383, P = 0.009), decreased with increasing severity of fibrosis. Using transient elastography, a cut-off value of 14.2 kPa predicted the presence of advanced liver fibrosis, but with a low positive predictive value. When we included platelet count, cholesterol, post-Fontan years and transient elastography values as a composite, the capability of predicting advanced liver fibrosis was the most satisfactory (C statistic 0.817 ± 0.071, P < 0.001). A cut-off value of 5.0 revealed a sensitivity of 78% and a specificity of 82%. CONCLUSIONS: In Fontan patients, diffusion-weighted imaging was helpful in detecting liver fibrosis that was correlated with hepatic dysfunction. A simple score was proposed for long-term surveillance and early detection of advanced liver disease in adult Fontan patients. For adult Fontan patients with a calculated score > 5.0, we may consider timely diffusion-weight imaging and early management for liver complications.

The utility of novel STE parameters in echocardiographic assessment of single ventricle after Fontan palliation.

Background and aims of the study A functionally single ventricle (FSV) refers to a group of congenital heart defects that are not amenable for biventricular correction. The Fontan operation is utilized as surgical treatment for most of FSV patients. The evaluation of FSV function is extremely difficult due to its unique pathophysiology. This study aimed to explore the efficacy of speckle tracking echocardiography (STE) parameters measured at rest and during exercise for comprehensive assessment of univentricular heart. METHODS: We enrolled 37 patients with a functionally single ventricle after the Fontan operation, hospitalized in the Department of Congenital Heart Defects between years 2019 and 2021.The echocardiographic stress tests were performed in the Echocardiography Laboratory of the Congenital Heart Defects Department. The study was conducted on a bicycle ergometer in a semi-recumbent position. The parameters obtained by speckle tracking echocardiography (STE): the longitudinal strain of the FSV free wall (Ɛ) and the longitudinal strain of myocardial layers: subendocardial, medial and subepicardial were analyzed. A transmural longitudinal strain gradient (TG) was calculated as the difference between longitudinal deformation of the subendocardial and subepicardial layers. Current results of cardiac magnetic resonance imaging (CMR) and cardio-pulmonary test (CPET) were also incorporated. Demographic data, past interventions, pharmacological treatment and comorbidities were extracted from medical records. RESULTS: Ɛ at rest and during exercise were not related to the parameters of physical capacity obtained on CPET nor to the CMR results. The transmural strain gradient was dependent on physical performance parameter- peak oxygen uptake- and related to the FSV ejection fraction calculated by magnetic resonance imaging. CONCLUSIONS: The transmural strain gradient and FSV free wall strain are readily measurable and suitable for evaluating single ventricle function. The TG is positively correlated with peak oxygen uptake during the cardiopulmonary test and with the ejection fraction derived from cardiac magnetic resonance imaging. The applicability of these findings in patients undergoing the Fontan procedure warrants further exploration.

Outcomes of extracardiac Fontan operation: A single institution experience with 398 patients.

OBJECTIVE: The study objective was to evaluate the outcomes of the extracardiac Fontan operation at a single institution. METHODS: We conducted a retrospective study of 398 patients from a single institution who underwent their initial extracardiac Fontan operation between 1997 and 2020. We determined the incidence of and risk factors for failure of the Fontan circulation, which includes death, Fontan takedown, heart transplantation, protein-losing enteropathy, plastic bronchitis, and functional status at the last follow-up. RESULTS: The median follow-up time was 10.3 years (interquartile range, 6.4-14.6). The overall survival was 96% and 86% at 10 and 20 years after extracardiac Fontan operation, respectively. There were 6 early deaths (6/398, 1.5%) and 15 late deaths (15/398, 3.8%). Forty-nine patients (12.5%) developed failure of the Fontan circulation. Freedom from the failure of Fontan circulation was 88% at 10 years and 76% at 20 years. Risk factors for failure of the Fontan circulation were right ventricular dominance (hazard ratio, 4.7; P < .001; 95% CI, 2.1-10.5), aortic atresia (hazard ratio, 5.5; P < .001; 95% CI, 2.3-12.8), and elevated mean pulmonary artery pressure (hazard ratio, 2.3; P = .002; 95% CI, 1.2-6.7). CONCLUSIONS: Rates of failure of the Fontan circulation are low after the contemporary extracardiac Fontan operation. Risk factors for failure of the extracardiac Fontan circulation include right ventricular dominance, aortic atresia, and elevated pulmonary artery pressures.

Early and long-term outcomes following cardiac surgery for patients with heterotaxy syndrome.

Objective: Heterotaxy syndrome is a complex multisystem abnormality historically associated with high morbidity and mortality. We sought to evaluate the early and long-term outcomes after cardiac surgery in heterotaxy syndrome. Methods: This is a single-center retrospective review of patients with heterotaxy syndrome undergoing single-ventricle palliation or primary or staged biventricular repair from 1998 to 2018. Patients were stratified by single ventricle versus biventricular physiology, and the severity of atrioventricular valve regurgitation. Demographics, anatomic characteristics, and early and late outcomes, including the length of stay, mortality, and surgical or catheter reinterventions, were analyzed. Results: Among 250 patients, 150 (60%) underwent biventricular repair. In-hospital mortality was 7.6% (n = 19). Median follow-up was 5.2 (range, 0-16) years. Among survivors to discharge, mortality was 19% (n = 44) and reintervention was 52% (n = 120). Patients with moderate/severe atrioventricular valve regurgitation were older (32 vs 16 months, P = .02), were more likely to experience adverse events during their index surgical admission (72% vs 46%, P < .001), and had longer in-hospital length of stay (20 vs 12 days, P = .009). Among patients with moderate to severe atrioventricular valve regurgitation, single-ventricle palliation is associated with a greater risk of unplanned reintervention compared with patients undergoing biventricular repair (hazard ratio, 2.13; CI, 1.10-4.12; P = .025). Conclusions: There was no significant difference in early or late outcomes in single-ventricle versus biventricular repair strategies in heterotaxy. In the subgroup of patients with moderate/severe atrioventricular valve regurgitation, patients who underwent single-ventricle palliation were 2.5 times more likely to need a late reintervention compared with those undergoing biventricular repair.

Trends and outcomes of heart transplantation in adults with congenital heart disease.

OBJECTIVES: Heart transplantation for adult congenital heart disease is complicated and associated with challenging pretransplant support, long waiting and high early post-transplant mortality. We explored if surgical and medical advances and allocation system changes have affected outcomes. METHODS: From United Network for Organ Sharing database, adults with congenital heart disease listed for heart transplantation were queried. To explore practice and outcome trends, patients were divided into 4 eras (eras 1-3: nearly 3 equal periods from 1992 to 2018, era 4: after 2018, corresponding with new allocation system). Univariate and multivariable analysis was performed to evaluate outcomes. RESULTS: A total of 2737 patients were listed. There was gradual increase in listed and transplanted patients, along with significant increase in use of mechanical support, simultaneous kidney and liver transplantation. While proportion of transplanted remained constant, there was decrease in proportion delisted/died after listing (P = 0.01) and waiting list duration (P = 0.01), especially in era 4. Thirty-day post-transplant mortality remains high; however, it has significantly improved starting era 3 (P = 0.01). Current survival at 1-year and 5-years is 85% and 65%, with improvement mainly related to decreased early death. On multivariable analysis, factors associated with survival were lower glomerular filtration rate (hazard ratio = 0.99, P = 0.042), bilirubin (hazard ratio = 1.17, P<0.001) and mechanical ventilation (hazard ratio = 2.3, P=0.004). CONCLUSIONS: Heart transplantation in adults with congenital heart disease is increasing, along with added complexity, higher usage of pretransplant mechanical support and simultaneous organ transplantation. Despite that, more complex patients do not experience worse outcomes. Early mortality improved but remains high. New donor allocation system allowed shorter waiting time and higher proportion transplanted without altering early mortality.

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.

Oxygen inhalation decreases the central venous pressure in adult patients late after Fontan operations.

BACKGROUND: Elevated central venous pressure (CVP) and decreased arterial oxygen saturation (SaO2) are the characteristics of patients after Fontan operations and determine morbidity and mortality in the long-term. Oxygen inhalation therapy theoretically increases SaO2 and may decrease the elevated CVP in these patients. However, there is no previous study to support this hypothesis. This study aimed to determine the acute effects of oxygen inhalation on the hemodynamics of adult patients late after Fontan operations using cardiac catheterization. METHODS: This study enrolled 58 consecutive adult patients (median age, 30 years; female, n = 24) who had undergone Fontan operations. We assessed the hemodynamic changes during oxygen inhalation (2 L/min) with a nasal cannula in cardiac catheterization. We divided the studied patients into two groups according to the reduction in CVP during oxygen inhalation using the median value: responders (>2 mmHg) and non-responders (≤2 mmHg). Clinical characteristics of the responders to oxygen inhalation were investigated with uni- and multivariate analyses. RESULTS: SaO2 increased from 93.3 % (91.3-94.5 %) to 97.5 % (95.2-98.4 %) (p < 0.001) and CVP decreased from 12 mmHg (11-14 mmHg) to 10 mmHg (9-12 mmHg) (p < 0.001) after oxygen inhalation. There was a weak but significant correlation between the increase in SaO2 and the decrease in CVP (R = 0.29, p = 0.025). Pulmonary blood flow increased from 4.1 L/min (3.5-5.0 L/min) to 4.4 L/min (3.7-5.3 L/min) (p = 0.007), while systemic blood flow showed no significant changes. A multivariate analysis revealed that high baseline CVP was associated with a larger decrease in CVP (>2 mmHg) after oxygen inhalation. CONCLUSIONS: Oxygen inhalation increased SaO2 and decreased CVP, especially in patients with high baseline CVP. Further studies with home oxygen therapy are needed to investigate the long-term effects of oxygen inhalation in adult patients who underwent Fontan operations.

Hemoadsorption Contribution in Failing Fontan Pediatric Heart Transplantation.

INTRODUCTION: A systemic inflammatory response is triggered in patients undergoing cardiothoracic surgery with cardiopulmonary bypass (CPB). This response is particularly evident in pediatric patients, especially those of low weight and after undergoing long CPB, and can severely impair the surgical result. Adsorptive blood purification techniques have been proposed to limit this systemic inflammatory response. To test its efficacy, we added the hemoadsorption filter Jafron HA 380 to CPB in a much compromised pediatric patient who underwent heart transplantation. METHODS: A 10-year-old single ventricle patient previously treated with Fontan operation was listed for heart transplantation due to the evidence of failing Fontan condition. He experienced many episodes of cardiac arrest and underwent heart transplantation in much compromised general and hemodynamic conditions. The hemoadsorption filter Jafron HA 380 was used for all the duration of CPB, and the inflammatory biomarker interleukin 6 (IL-6) was assayed. RESULTS: Postoperative outcome was uneventful and comparable to that of elective pediatric heart transplantation. IL-6 levels showed an impressive postoperative reduction, and after 2 days, the IL-6 level was comparable with a typical uneventful post-transplant course. CONCLUSIONS: The use of hemoadsorption filter can contribute to improve the pediatric transplant results, especially in very high-risk patients.

Mitochondrial dysfunction is associated with the severity of liver fibrosis in patients after the Fontan operation.

The gold standard for determining the severity of liver disease in Fontan patients is now liver biopsy. Since it is an invasive procedure, this study determined the possibility of applying mitochondrial function from isolated peripheral blood mononuclear cells (PBMCs) as a non-invasive indicator of liver fibrosis. Fontan patients (n = 37) without known liver disease were analysed cross-sectionally. Patients were classified according to their histology using the METAVIR score as follows; F0/F1-no/mild fibrosis; F2-moderate fibrosis; and F3/F4-cirrhosis. Peripheral blood mononuclear cells were assessed for mitochondrial activity and apoptosis. This study did not find any significant differences in cardiac function among the groups according to liver histology. Interestingly, our findings indicated a significant decrease in maximal respiration and spare respiratory capacity, in both the moderate (F2) and cirrhosis (F3/F4) groups compared with the group without significant fibrosis (F0/F1). Moreover, the cirrhosis group exhibited higher levels of apoptosis and lower levels of live cells, compared with both the moderate and no significant fibrosis groups. In conclusion, the degree of liver fibrosis in Fontan patients is strongly correlated with mitochondrial dysfunction in PBMCs. Mitochondrial function and apoptosis could potentially serve as novel markers for tracking the progression of liver fibrosis in these patients.

Management of Junctional Rhythm in Patients After the Fontan Operation: A Multicenter Congenital Cardiology Survey.

Sinus node dysfunction with concomitant junctional rhythm (JR) is frequently observed among Fontan patients and has been recognized as a contributor to heart failure. The impact and management of JR is unclear. A survey was mailed to all members of the Pediatric and Congenital Electrophysiology society (PACES) and members were asked to forward the questionnaire to their non-electrophysiology colleagues. Responses were received from 154 physicians (88 electrophysiologists (EP's) and 66 non-EP's (46 pediatric cardiologists and 20 adult congenital cardiologists). There were few differences in the response between EP's and non-EP's. Overall, 57% recommended an annual ambulatory ECG (AECG). A significant majority (80%) opted to continue to follow patients with significant periods of JR on AECG as long as the patients were asymptomatic, and showed no echocardiographic signs of cardiac decompensation. However, 84% would place a pacemaker in a patient with JR who was having open chest surgery for other reasons. Finally, pacemaker placement would be performed by 91% if a patient with JR showed signs of heart failure. Most congenital cardiologists would not recommend pacemaker placement in asymptomatic Fontan patients with JR. Further studies are needed on the Fontan population to determine the impact of SND and JR on longer term outcomes and to determine the role and optimal timing of pacemaker placement in these patients.

Late development of intra-atrial reentrant tachycardia in lateral tunnel Fontan patients and the preventive role of prophylactic cryoablation.

OBJECTIVE: Intra-atrial reentrant tachycardia is an important late-onset complication in patients undergoing the Fontan procedure. However, the protective effects of prophylactic cryoablation against late-onset intra-atrial reentrant tachycardia are unclear. This study investigated the late development of intra-atrial reentrant tachycardia in patients undergoing the lateral tunnel Fontan procedure and the role of prophylactic cryoablation. METHODS: This was a single-center retrospective cohort study of patients who underwent the lateral tunnel Fontan procedure between 1988 and 2003. Univariate and multivariable competing risks regression models were used to determine the associations of prophylactic cryoablation and covariates with the outcomes of interest: late-onset intra-atrial reentrant tachycardia, all-cause mortality, and cardiovascular mortality. RESULTS: In total, 130 patients who underwent the lateral tunnel Fontan procedure, 30 of whom had undergone prophylactic cryoablation, were included in this study and followed up for a median of 23.6 years (interquartile range, 17.7-26.5). Intra-atrial reentrant tachycardia was identified in 14 patients (10.8%), none of whom underwent prophylactic cryoablation. The median Fontan-to-intra-atrial reentrant tachycardia time was 17.2 years (interquartile range, 11.1-23.1). Prophylactic cryoablation was protective against late-onset intra-atrial reentrant tachycardia (P < .0001) and cardiovascular mortality (P < .0001) in the type 3 test. CONCLUSIONS: None of the patients who underwent prophylactic cryoablation developed late-onset intra-atrial reentrant tachycardia during a median follow-up time of 22.9 years. Our study demonstrated that prophylactic cryoablation was effective in preventing late-onset intra-atrial reentrant tachycardia and cardiovascular mortality in patients undergoing the lateral tunnel Fontan.

Transcatheter thrombectomy of acute pulmonary embolism in an adult Fontan patient: a case report.

Background: The Fontan operation is a well-described palliative procedure for functional single-ventricle patients. This population has an increased risk of thrombo-embolic events. Adequate imaging, and therefore diagnosis, requires an understanding of the unique anatomy and physiology of a Fontan. Optimal strategies for the prevention and treatment of thrombo-embolic complications in the Fontan population are poorly defined. Case summary: A 28-year-old female with a history of Ebstein anomaly of the tricuspid valve status post-Fontan presented with chest pain and acute hypoxia. Computed tomographic angiography (CTA) reported a submassive pulmonary embolism (PE). She was initiated on a heparin drip. Catheterization demonstrated elevated Fontan pressures and a large thrombus in the right lower pulmonary artery that was removed with an aspiration device. The patient was transitioned to a direct oral anticoagulant (DOAC) following the procedure. Discussion: Thrombotic complications are common in the adult Fontan population. Given the morbidity and mortality associated with this complication, the use of proper imaging techniques is imperative. Traditional CTA imaging for PE in Fontan patients often has contrast filling defects related to their anatomy and physiology. Utilization of adequate imaging techniques helps decrease cost and additional radiation exposure. In addition, it avoids inappropriate hospitalization, need for anticoagulation, and potential need for catheterization toconfirm or exclude the presence of PE. For Fontan patients with a thrombus, prior event, and no contraindications, current guidelines recommend oral anticoagulation with a vitamin K antagonist; however, there are increasing data on the use of DOACs in this population.

Duplex ultrasound abnormalities of the lower limb veins might precede clinical venous reflux signs in post-Fontan adolescents and young adults.

OBJECTIVE: After the Fontan operation (ie, direct anastomosis of the caval veins to the pulmonary arteries, constituting right ventricular bypass circulation), high central venous pressure can lead to peripheral venous stasis and venous valvar insufficiency. We hypothesized that post-Fontan patients are at a higher risk of developing lower extremity venous lesions detectable using duplex ultrasound, even if clinical signs of chronic venous disease might not be evident. METHODS: A total of 87 transplantation-free survivors after the Fontan procedure who reached adolescence or young adulthood (current age, 15-30 years) participated in a leg vein duplex ultrasound study. The median age at the Fontan procedure, median age at the vein study, and median interval between the two were 3.65 years (interquartile range [IQR], 3.1-5.3 years), 21.7 years (IQR, 18.9-24.7 years), and 16.6 years (IQR, 14.9-19.4 years), respectively. Duplex ultrasound scanning was performed using a venous ultrasound imaging system (Logiq P7; GE Healthcare). The patients were categorized according to the presence of venous reflux (VR) in the superficial, deep, or perforating venous systems: no VR, superficial VR (SVR), deep VR (DVR), perforating VR (PVR), and a combination of multiple venous systems. Correlation of the duplex ultrasound-detected venous lesions with clinical severity using the modified CEAP (clinical, etiological, anatomical, pathophysiological) classification was analyzed using Spearman's correlation analysis. RESULTS: Leg pain was reported by 48 of 87 patients (55.2%). The duplex ultrasound findings for the cohort were no VR in 21 patients (24.1%), SVR in 22 (25.3%), isolated PVR in 21 (24.1%), and reflux of multiple venous systems in 23 patients, including SVR and PVR in 19, DVR and PVR in 1, and SVR, PVR, and DVR in 3 patients. Although the patients with advanced venous lesions detected by duplex ultrasound tended to have a higher CEAP clinical class (P < .001), VR of any venous system on duplex ultrasound was present even in patients with a lower CEAP clinical class. The CEAP clinical class was C0 for 66 patients (76%), and VR of any venous system was present on duplex ultrasound in 66 patients (76%). CONCLUSIONS: The prevalence of lower extremity venous lesions detected by duplex ultrasound is strikingly high in post-Fontan adolescents and young adults, and duplex ultrasound-detected venous abnormalities can precede clinical manifestations. Early detection and timely intervention for leg vein problems are mandatory for post-Fontan patients, especially for those considered to have risk factors for developing chronic lower extremity venous disease.

Associations Between Characteristics of Individuals With Fontan Circulation With Blood and Urine Biomarkers of Kidney Injury and Dysfunction.

Background Fontan circulation is associated with kidney injury and dysfunction, often unappreciated until Fontan circulatory failure. We hypothesized that cystatin C-estimated glomerular filtration rate (eGFR) would identify chronic kidney disease more frequently and that urine kidney injury biomarkers would be higher with declining Fontan physiological features. Methods and Results We enrolled 100 ambulatory individuals. Blood and urinary laboratory measurements were compared with demographics and clinically obtained data. Different eGFR equations were used for individuals aged ≥19 years and <19 years. Chronic kidney disease was defined as eGFR <90 mL/min per 1.73 m2. Median (25th-75th percentile) age was 19 (14-26) years, and 43% were female patients. Cystatin C eGFR detected chronic kidney disease (37%) in more patients than creatinine eGFR (11%). Cystatin C eGFR was positively associated, and skeletal muscle mass was negatively associated, with creatinine eGFR in both univariate (cystatin C eGFR ß=0.44±0.12, P=0.0006; skeletal muscle mass ß=-0.72±0.32, P=0.03) and multivariable analysis (cystatin C eGFR ß=0.43±0.12, P=0.0005; skeletal muscle mass ß=-0.69±0.29, P=0.02). Urine neutrophil gelatinase-associated lipocalin concentration correlated with Fontan pressure (r=0.28; P=0.04), ventricular end-diastolic pressure (r=0.28; P=0.04), and body fat mass (r=0.26; P=0.03). Conclusions Cystatin C eGFR identified more kidney dysfunction, likely attributable to creatinine eGFR being confounded by skeletal muscle mass. Elevated urine neutrophil gelatinase-associated lipocalin was associated with worse Fontan hemodynamics and higher percentage body fat, suggesting that higher venous pressure and higher adiposity are associated with ongoing kidney injury.

Pulmonary Complications in Patients With Fontan Circulation: JACC Review Topic of the Week.

The Fontan operation has resulted in significant improvement in survival of patients with single ventricle physiology. As a result, there is a growing population of individuals with Fontan physiology reaching adolescence and adulthood. Despite the improved survival, there are long-term morbidities associated with the Fontan operation. Pulmonary complications are common and may contribute to both circulatory and pulmonary insufficiency, leading ultimately to Fontan failure. These complications include restrictive lung disease, sleep abnormalities, plastic bronchitis, and cyanosis. Cyanosis post-Fontan procedure can be attributed to multiple causes including systemic to pulmonary venous collateral channels and pulmonary arteriovenous malformations. This review presents the unique cardiopulmonary interactions in the Fontan circulation. Understanding the cardiopulmonary interactions along with improved recognition and treatment of pulmonary abnormalities may improve the long-term outcomes in this growing patient population. Interventions focused on improving pulmonary function including inspiratory muscle training and endurance training have shown a promising effect post-Fontan procedure.

Magnetic resonance three-dimensional steady-state free precession imaging of the thoracic duct in patients with Fontan circulation and its relationship to outcomes.

BACKGROUND: Lymphatic complications are common in patients with Fontan circulation. Three-dimensional balanced steady-state free precession (3D bSSFP) angiography by cardiovascular magnetic resonance (CMR) is widely used for cardiovascular anatomical assessment. We sought to determine the frequency of thoracic duct (TD) visualization using 3D bSSFP images and assess whether TD characteristics are associated with clinical outcomes. METHODS: This was a retrospective, single-center study of patients with Fontan circulation who underwent CMR. Frequency matching of age at CMR was used to construct a comparison group of patients with repaired tetralogy of Fallot (rTOF). TD characteristics included maximum diameter and a qualitative assessment of tortuosity. Clinical outcomes included protein-losing enteropathy (PLE), plastic bronchitis, listing for heart transplantation, and death. A composite outcome was defined as presence of any of these events. RESULTS: The study included 189 Fontan patients (median age 16.1 years, IQR 11.0-23.2 years) and 36 rTOF patients (median age 15.7 years, IQR 11.1-23.7 years). The TD diameter was larger (median 2.50 vs. 1.95 mm, p = 0.002) and more often well visualized (65% vs. 22%, p < 0.001) in Fontan patients vs. rTOF patients. TD dimension increased mildly with age in Fontan patients, R = 0.19, p = 0.01. In Fontan patients, the TD diameter was larger in those with PLE vs. without PLE (age-adjusted mean 4.11 vs. 2.72, p = 0.005), and was more tortuous in those with NYHA class ≥ II vs. class I (moderate or greater tortuosity 75% vs. 28.5%, p = 0.02). Larger TD diameter was associated with a lower ventricular ejection fraction that was independent of age (partial correlation = - 0.22, p = 0.02). More tortuous TDs had a higher end-systolic volume (mean 70.0 mL/m2 vs. 57.3 mL/m2, p = 0.03), lower creatinine (mean 0.61 mg/dL vs. 0.70 mg/dL, p = 0.04), and a higher absolute lymphocyte count (mean 1.80 K cells/µL vs. 0.76 K cells/µL, p = 0.003). The composite outcome was present in 6% of Fontan patients and was not associated with TD diameter (p = 0.50) or tortuosity (p = 0.09). CONCLUSIONS: The TD is well visualized in two-thirds of patients with Fontan circulation on 3D-bSSFP images. Larger TD diameter is associated with PLE and increased TD tortuosity is associated with an NYHA class ≥ II.

Therapy of Patients with Cardiac Malposition.

Positional abnormalities per se do not require treatment, but in their place, the accompanying pulmonary pathology in dextroposition patients and pathophysiologic hemodynamic abnormalities resulting from multiple defects in patients with cardiac malposition should be the focus of treatment. At the time of the first presentation, treating the pathophysiologic aberrations caused by the defect complex, whether it is by improving the pulmonary blood flow or restricting it, is the first step. Some patients with simpler or single defects are amenable to surgical or transcatheter therapy and should be treated accordingly. Other associated defects should also be treated appropriately. Biventricular or univentricular repair dependent on the patient's cardiac structure should be planned. Complications in-between Fontan stages and after conclusion of Fontan surgery may occur and should be promptly diagnosed and addressed accordingly. Several other cardiac abnormalities unrelated to the initially identified heart defects may manifest in adulthood, and they should also be treated.

Successful coil embolisation of tortuous portosystemic venous shunts using a steerable microcatheter in a patient with polysplenia after a Fontan-type operation.

Portosystemic venous shunts occur in patients with polysplenia after the Fontan operation. In the long term, these shunts are associated with hyperammonaemia and portal-systemic encephalopathy. Since some shunts are long and tortuous, catheter interventions to close them could be challenging. Instead, a steerable microcatheter could be used for coil embolisation of tortuous portosystemic venous shunts.

Clinical aspects and targeted inspiratory muscle training in children and adolescents with Fontan circulation: a randomized controlled trial.

Background: Since 1968, thousands of patients with a morphologically or functionally univentricular heart have been treated with a total cavopulmonary connection/Fontan operation. Because of the resulting passive pulmonary perfusion, blood flow is assisted by the pressure shift during respiration. Respiratory training is known to improve exercise capacity and cardiopulmonary function. However, there are limited data on whether respiratory training can also improve physical performance after Fontan surgery. The aim of the present study was to clarify the effects of six months of daily home-based inspiratory muscle training (IMT) aimed at increasing physical performance by strengthening respiratory muscles, improving lung function and peripheral oxygenation. Methods: In this non-blinded randomized controlled trial, the effects of IMT on lung capacity and exercise capacity were measured in a large cohort of 40 Fontan patients (25% female; 12.3±2.2 years) who were under regular follow-up by the outpatient clinic of the Department of Congenital Heart Defects and Pediatric Cardiology of the German Heart Center Munich. After a lung function test and a cardiopulmonary exercise test, patients were randomly assigned in a parallel arm design to either an intervention group (IG) or a control group (CG) via stratified and computer-generated letter randomization from May 2014 to May 2015. The IG completed a daily, telephone-monitored IMT of three sets of 30 repetitions for six months with an inspiratory resistive training device (POWERbreathe medic®), the CG continued their usual daily activities without an IMT until the second examination within the timeframe of November 2014 until November 2015. Results: After six months of IMT, lung capacity values in the IG (n=18) did not increase significantly compared to the CG [n=19; ΔFVC: IG: 0.21±0.16 l vs. CG 0.22±0.31 l; P=0.946 (CI: -0.16, 0.17); ΔFEV1: CG: 0.14±0.30 vs. IG: 0.17±0.20 P=0.707 (CI: -0.20, 0.14)]. Exercise capacity did not improve significantly, yet the maximum workload achieved trended to improve with an increase of 14% in the IG vs. 6.5% in the CG [P=0.113 (CI: -15.8, 1.76)]. There was a significant increase of oxygen saturation at rest in the IG compared to the CG [IG: 3.31%±4.09% vs. CG: 0.17%±2.92%, P=0.014 (CI: -5.60, -0.68)]. Compared to the CG, the mean oxygen saturation at peak exercise no longer dropped below 90% in the IG. This observation is thus not statistically significant, yet of clinical relevance. Conclusions: The results of this study show benefits of an IMT in young Fontan patients. Even if some data are not statistically significant, they may still be clinically relevant and may contribute to a multidisciplinary approach in patient care. IMT should therefore be an additional target and integrated into the training program to improve the prognosis of Fontan patients. Trial Registration: German Clinical Trials Register; DRKS.de; registration ID: DRKS00030340.