Abdominal CT and MRI Findings of Portal Hypertension in Children and Adults with Fontan Circulation.

Background Portal hypertension in the Fontan circulation is a function of elevated systemic venous pressure and liver fibrosis. Purpose To quantify the prevalence of radiologic evidence of portal hypertension and elevated VAST score (one point each for varices, ascites, splenomegaly, and thrombocytopenia) of 2 or greater in children and adults with Fontan circulation and to determine the association with hemodynamics and adverse outcomes. Materials and Methods This was a retrospective study of individuals with Fontan circulation who underwent abdominal MRI or CT for focal liver lesion surveillance between January 2012 and December 2019. Portal hypertension was defined as the presence of at least two of the following: varices, ascites, or splenomegaly. Fontan deterioration was defined as a composite of heart failure signs or symptoms requiring diuretic escalation, placement of a ventricular assist device, heart transplant, or death. Relationships between variables and the composite end point were assessed using univariable and multivariable logistic regression. Results A total of 123 patients (age range, 9-55 years; 32 children) were evaluated (median age, 23 years; IQR, 17-30 years; 63 male patients). Median time since diagnosis of Fontan circulation was 16 years (IQR, 12-23 years). Twenty-five of the 123 patients (20%) had radiologic evidence of portal hypertension, and 34 (28%) had a VAST score of 2 or greater. Fontan deterioration occurred in 25 of the 123 patients (20%); median follow-up duration was 0.4 year (IQR, 0.1-3.1 years). Compared with patients who had Fontan circulation without deterioration, patients with Fontan deterioration were more likely to have moderate or severe ventricular systolic dysfunction (P < .01), moderate or severe atrioventricular valve regurgitation (P < .01), higher Fontan pressure (P = .01), radiologic evidence of portal hypertension (P < .01), and VAST score of 2 or greater (P < .01). Conclusion Radiologic evidence of portal hypertension at abdominal imaging in children and adults with Fontan circulation was associated with higher venous pressures and an increased risk for Fontan deterioration. These characteristics may be used to identify patients who warrant comprehensive hemodynamic evaluation. © RSNA, 2022.

Relation of Magnetic Resonance Elastography to Fontan Circulatory Failure in a Cohort of Pediatric and Adult Patients.

Elevated magnetic resonance elastography (MRE)-derived liver stiffness may be associated with worse outcomes in people with Fontan circulation. We sought to evaluate the association between liver stiffness and Fontan failure or portal hypertension. Single center cross-sectional retrospective study of people with Fontan circulation who underwent MRE between 2011 and 2020. The cohort was divided into adult (age ≥ 21 years) and pediatric (< 21 years) groups. Fontan circulatory failure (FF) was defined as any of the following: death, transplantation, ventricular assist device, heart failure symptoms requiring escalation of diuretics. Radiologic portal hypertension was defined as the presence of one or more of the following: splenomegaly, ascites, or gastrointestinal varices. 128 patients were included (average age = 22.6 ± 8.7 years) and 58 (45%) were children. Median liver stiffness was 4.3 kPa (interquartile range (IQR) 3.8-5.8) for the entire cohort. Thirty patients (23%) developed FF (16 adults, 14 children). Liver stiffness was higher in adults with FF compared to those without FF (4.9 (IQR 4.0-6.0) vs. 4.2 (IQR 3.8-4.7) kPa, p = 0.04). There was no difference in liver stiffness between pediatric patients with and without FF (4.4 (IQR 4.1-5.4) vs. 4.4 (IQR 3.8-5.0), p = 0.5). Adults with radiologic portal hypertension and adults with moderate or severe atrioventricular valve regurgitation had higher liver stiffness than adults without. MRE-derived liver stiffness is associated with atrioventricular valve regurgitation, portal hypertension, and poor clinical outcomes in adults with Fontan circulation. There was no association between liver stiffness and FF in pediatric patients. This difference may be due to the progressive nature of Fontan-associated liver disease.

Lymphopenia in adults after the Fontan operation: prevalence and associations.

Lymphopenia is common in adults who have had a Fontan operation although its aetiology and clinical implications remain unknown. Previous work suggests an association between lymphopenia and both liver disease and splenomegaly. The objective of this study was to assess the prevalence of lymphopenia in adults with a Fontan circulation and evaluate its associations with risk factors and clinical outcomes. Using a retrospective cohort study design, we studied 73 adult Fontan patients (age 25.0 ± 8.4 years) who had a complete blood count and abdominal imaging performed. Patients with protein-losing enteropathy were excluded. Clinical data were extracted from hospital records. The mean white blood cell count was 6580 ± 220/ml with a mean lymphocyte count of 1223 ± 508/ml. Lymphopenia, defined as lymphocyte count <1000/ml, was present in 23 (32%) patients. Patients with lymphopenia had a lower total white blood cell count (5556 ± 2517 versus 7136 ± 1924/ml, p = 0.009) and a lower platelet count (162 ± 69 versus 208 ± 69 k/ml, p = 0.008). Lymphopenia was also associated with findings of portal hypertension, including splenomegaly (36 versus 14%, p = 0.04), varices (22 versus 6%, p = 0.04), and ascites (39 versus 14%, p = 0.02). Lymphopenia did not correlate with any cardiac imaging, haemodynamic or exercise testing variables. In conclusion, lymphopenia is common in adult Fontan patients and is associated with markers of portal hypertension. Larger studies are needed to better define the relationship between lymphopenia and clinical outcomes.

Hepatic Steatosis in Patients With Single Ventricle and a Fontan Circulation.

Background Hepatic steatosis, caused by nonalcoholic fatty liver disease, is a leading cause of chronic liver disease. The interplay between hepatic steatosis and the development of liver disease following the Fontan procedure is not well understood. This study examined the prevalence and associations of hepatic steatosis in patients with a Fontan circulation. Methods and Results This was a single-center retrospective study of 95 patients with a Fontan circulation with liver magnetic resonance imaging performed between 2012 and 2019. The average age at magnetic resonance imaging was 21.5±8.5 years. The percent liver fat signal was determined using magnetic resonance chemical shift-encoded proton density fat fraction imaging. Hepatic steatosis was defined as liver fat ≥5% and was present in 10.5% of the cohort. The presence of hepatic steatosis was associated with higher body mass index (29±4 versus 24±6 kg/m2, P=0.006), a higher frequency of obesity (50% versus 12%, P=0.015), lower high-density lipoprotein cholesterol (35±9 versus 43±14 mg/dL, P=0.050), and greater subcutaneous fat thickness (2.6±0.7 versus 1.8±1.0 cm, P=0.043). There was no association between hepatic steatosis and cardiovascular imaging or hemodynamic variables from cardiac catheterization. Conclusions Risk factors for hepatic steatosis in patients with Fontan circulation include obesity and dyslipidemia, similar to what is seen in the general population. Fontan hemodynamics were not associated with hepatic steatosis.

Long-Term Kidney Function After the Fontan Operation: JACC Review Topic of the Week.

The Fontan procedure has improved survival and quality of life for patients with single ventricle physiology. Along with extended life expectancy comes a growing population that is experiencing long-term multiorgan adverse effects. Whereas cardiorenal interactions have been extensively studied in patients with a structurally normal heart, these are less well understood in patients with a single ventricle. Several studies have investigated the prevalence of reduced glomerular filtration rate and albuminuria in the Fontan population; however, the long-term implication of renal dysfunction is not well established in this population. This paper provides a concise review of the published reports on the pathophysiology and spectrum of Fontan-associated renal disease. It also identifies gaps in currently available evidence that can guide ongoing and future research.