Lymphopenia in adults after the Fontan operation: prevalence and associations

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

Background

Patients 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.

Methods

Patients 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.

Results

In 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).

Conclusions

Adult 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.

The Fontan immunophenotype and post-transplant outcomes in children: A multi-institutional study

BACKGROUND

Patients after Fontan palliation represent a growing pediatric population requiring heart transplant (HTx) and often have lymphopenia (L) and/or hypogammaglobinemia that may be exacerbated by protein-losing enteropathy (PLE, P). The post-HTx effects of this altered immune phenotype are not well studied.

METHODS

In this study of the Pediatric Heart Transplant Society Registry, 106 Fontan patients who underwent HTx between 2005 and 2018 were analyzed. The impact of lymphopenia and PLE on graft survival, infection, rejection, and malignancy was analyzed at 1 and 5 years post-HTx.

RESULTS

The following combinations of lymphopenia and PLE were noted: +L+P, n = 37; +L-P, n = 23; -L+P, n = 10; and -L-P, n = 36. Graft survival between the groups was similar within the first year after transplant (+L+P: 86%, +L-P: 86%, -L+P: 87%, -L-P: 89%, p = .9). Freedom from first infection post-HTx was greatest among -L-P patients compared to patients with either PLE, lymphopenia, or both; with a 22.1% infection incidence in the -L-P group and 41.4% in all others. These patients had a significantly lower infection rate in the first year after HTx (+L+P: 1.03, +L-P: 1, -L+P: 1.3, -L-P: 0.3 infections/year, p < .001) and were similar to a non-single ventricle CHD control group (0.4 infections/year). Neither freedom from rejection nor freedom from malignancy 1 and 5 years post-HTx, differed among the groups.

CONCLUSIONS

Fontan patients with altered immunophenotype, with lymphopenia and/or PLE, are at increased risk of infection post-HTx, although have similar early survival and freedom from rejection and malignancy. These data may encourage alternative immunosuppression strategies and enhanced monitoring for this growing subset of patients.

Increased risk of infections in pediatric Fontan patients after heart transplantation

BACKGROUND

Infectious complications are a major cause of morbidity and mortality after HT. Fontan patients may be more susceptible to post-HT infections.

METHODS

This was a single-center, retrospective cohort analysis of pediatric patients undergoing HT for FF physiology or DCM, who underwent induction with ATG. The primary endpoint was an infection in the first 180 days post-HT, defined as positive (1) blood/urine/respiratory culture; (2) viral PCR; (3) skin or wound infection; and/or (4) culture-negative infection if ≥5 days of antibiotics were completed. Secondary endpoints included (1) cell counts after ATG; (2) PTLD; and (3) rejection (≥Grade 2R ACR or pAMR2) in the first 180 days post-HT.

RESULTS

A total of 59 patients (26 FF, 33 DCM) underwent HT at 14.7 (IQR 10.6, 19.5) and 11.7 (IQR 1.4, 13.6) years of age, respectively. The median total ATG received was 7.4 (IQR 4.9, 7.7) vs 7.5 (IQR 7.3, 7.6) mg/kg (p = NS) for FF and DCM patients, respectively. Twenty-three patients (39%) developed an infection 180 days post-HT, with a higher rate of infection in FF patients (54% vs 27%, p = .03). Adjusted for pre-transplant absolute lymphocyte count, FF patients had a higher risk of infection at 30 days post-HT (OR 7.62, 95% CI 1.13-51.48, p = .04). There was no difference in the incidence of PTLD (12% vs 0%; p = .08) or rejection (12% vs 21%; p = .49).

CONCLUSION

Compared to DCM patients, FF patients have a higher risk of infection. Modifications to induction therapy for FF patients should be considered.

Fontan Circulation Associated Organ Abnormalities Beyond the Heart, Lungs, Liver, and Gut: A Systematic Review

Introduction

Patients with a Fontan circulation are at risk for sequelae of Fontan physiology during follow-up. Fontan physiology affects all organ systems and an overview of end-organ damage is needed.

Methods

We performed a systematic review of abnormalities in multiple organ systems for patients with a longstanding Fontan circulation. We searched online databases for articles describing abnormalities in multiple organ systems. Cardio-pulmonary abnormalities, protein losing enteropathy, and Fontan associated liver disease have already extensively been described and were excluded from this systematic review.

Results

Our search returned 5,704 unique articles. After screening, we found 111 articles relating to multiple organ systems. We found abnormalities in, among others, the nervous system, pituitary, kidneys, and musculoskeletal system. Pituitary edema—relating to the unique pituitary vasculature- may affect the thyroid axis. Renal dysfunction is common. Creatinine based renal function estimates may be inappropriate due to myopenia. Both lean muscle mass and bone mineral density are decreased. These abnormalities in multiple organ systems may be related to Fontan physiology, cyanosis, iatrogenic factors, or lifestyle.

Conclusions

Health care providers should be vigilant for hypothyroidism, visual or hearing deficits, and sleep disordered breathing in Fontan patients. We recommend including cystatin C for assessment of renal function. This review may aid health care providers and guide future research.

Systematic Review Registration:https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021232461, PROSPERO, identifier: CRD42021232461.

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.

Clonal Cytopenia of Undetermined Significance in a Patient with Congenital Wilms' Tumor 1 and Acquired DNMT3A Gene Mutations

Congenital mutations of the Wilms' tumor 1 (WT1) gene can lead to various abnormalities, including renal/gonadal developmental disorders and cardiac malformations. Although there have been many reports of somatic WT1 mutations in patients with acute myeloid leukemia and myelodysplastic syndrome, congenital WT1 mutations have not been reported in hematological disorders. We herein report a patient with early-onset clonal cytopenia of undetermined significance that was associated with a congenital mutation of WT1 and an acquired mutation of DNMT3A [encoding DNA (cytosine-5)-methyltransferase 3A].

Neutrophil-to-Lymphocyte and Platelet-to-Lymphocyte Ratio in Univentricular Patients From Birth to Follow-Up After Fontan-Predicting Lymphatic Abnormalities

Background: Reliable laboratory parameters identifying complications after Fontan surgery including the lymphatic abnormalities and the development of protein-losing enteropathy (PLE) are rare. Neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocte ratio (PLR) are inflammatory markers and have been studied to predict outcome and prognosis in various diseases. The aim of this study was to investigate NLR and PLR from birth to follow-up after Fontan and evaluate their use as prognostic parameters for single ventricle patients regarding the development of lymphatic malformations during follow-up. Materials and Methods: Sixty-six univentricular patients who underwent Fontan surgery and had 6-month follow-up magnetic resonance imaging (MRI) with T2 weighted lymphatic imaging after total cavopulmonary connection (TCPC) surgery were included in the study. NLR and PLR were determined at specific time points, from neonatal age to follow-up after Fontan operation and correlated to data from the MRI 6 months after Fontan. Results: NLR and PLR increase significantly over time from the first surgery during infancy to the follow-up after Fontan (both p < 0.0001), with a significant increase after the Glenn surgery for both ratios (each p < 0.0001). Higher NLR (p = 0.002) and higher PLR (p = 0.004) correlated with higher-grade classification of lymphatic abnormalities in T2-weighted imaging 6 months after Fontan surgery and higher NLR correlated with higher transpulmonary gradient prior to Fontan surgery (p = 0.035) Both ratios showed a significant correlation to total protein at follow-up (NLR p = 0.0038; PLR<0.0001). Conclusion: Increased NLR and PLR correlate with higher degree lymphatic malformations after TCPC and therefore might contribute as valuable additional biomarker during follow-up after TCPC. NLR and PLR are simple, inexpensive and easily available parameters to complement diagnostics after TCPC.

Association of Lymphatic Abnormalities with Early Complications after Fontan Operation

Background  Increased central venous pressure is inherent in Fontan circulation but not strongly related to Fontan complication. Abnormalities of the lymphatic circulation may play a crucial role in early Fontan complications.

Methods  This was a retrospective, single-center study of patients undergoing Fontan operation from 2008 to 2015. The primary outcome was significant early Fontan complication defined as secondary in-hospital treatment due to peripheral edema, ascites, pleural effusions, protein-losing enteropathy, or plastic bronchitis. All patients received T2-weighted magnetic resonance images to assess abdominal and thoracic lymphatic perfusion pattern 6 months after Fontan completion with respect to localization, distribution, and extension of lymphatic perfusion pattern (type 1–4) and with application of an area score (0–12 points).

Results  Nine out of 42 patients developed early Fontan complication. Patients with complication had longer chest tube drainage (mean 28 [interquartile range [IQR]: 13–60] vs. 13 [IQR: 2–22] days, p  = 0.01) and more often obstructions in the Fontan circuit 6 months after surgery (56 vs. 15%, p  = 0.02). Twelve patients showed little or no abnormalities of lymphatic perfusion (lymphatic perfusion pattern type 1). Most frequently magnetic resonance imaging showed lymphatic congestion in the supraclavicular region (24/42 patients). Paramesenteric lymphatic congestion was observed in eight patients. Patients with early Fontan complications presented with higher lymphatic area score (6 [min–max: 2–10] vs. 2 [min–max: 0–8]), p  = 0.001) and greater distribution and extension of thoracic lymphatic congestion (type 3–4: n  = 5/9 vs. n  = 1/33, p  = 0.001).

Conclusion  Early Fontan complication is related to hemodynamic factors such as circuit obstruction and to the occurrence and extent of lymphatic congestion.

Imaging of Fontan-associated liver disease

The Fontan operation has dramatically altered the natural history of functionally single ventricle congenital heart disease. Patients who have undergone the Fontan operation are living longer and, thus, noncardiac morbidity resulting from the Fontan operation is increasingly being recognized. Fontan-associated liver disease (FALD), one of the chief morbidities following the Fontan operation, is believed to be a multifactorial process that manifests as hepatic congestion and fibrosis, portal hypertension, and development of focal liver lesions, including malignant tumors. This article reviews the imaging findings of FALD in the pediatric and young adult population, reviews the literature related to the imaging of FALD and discusses possible screening algorithms for this population. The need for further research to better understand the causes of FALD, to establish if early liver stiffness measurements (or their change over time) predict long-term outcomes and complications, and to define optimal liver screening procedures is highlighted.