Fontan-associated liver disease: Diagnosis, surveillance, and management

Importance of gamma-glutamyl transferase elevation in patients with Fontan-associated liver disease

AIM

In patients with Fontan-associated liver disease (FALD), gamma-glutamyl transferase (GGT) levels are often elevated, however, its clinical importance is unclear. We investigated the relationship between the clinical course of FALD and GGT levels.

METHODS

We enrolled 145 patients with FALD who underwent right-heart catheterization (RHC) and visited our department. Ursodeoxycholic acid (UDCA) was administered to 62 of the patients. Patients with GGT levels <50 and ≥50 U/L were compared. Follow-up RHC was undertaken in 76 patients. Cases in which GGT levels decreased by ≥10% or <50 U/L were defined as improved (n = 33).

RESULTS

Patients with GGT levels ≥50 U/L had significantly lower levels of albumin and higher levels of alanine transaminase (ALT) but no significant differences in RHC factors. Over a 4.6-year period, 43.4% showed improvement in GGT levels. Improved cases had significantly lower total bilirubin (1.1 vs. 1.6 mg/dL), AST (22 vs. 28 U/L), and ALT (18 vs. 27 U/L) levels than nonimproved cases (n = 29, p < 0.05), and the change in platelet count (-0.5 vs. -3.0 × 10-4/μL) was significantly lower in the latter (p = 0.03). The improvement rate was significantly higher in UDCA-treated cases (55.2%) with GGT levels ≥50 U/L compared to cases not treated with UDCA (18.2%, p = 0.04).

CONCLUSION

In cases of FALD with no improvement in GGT level, the platelet count decreased over time, suggesting progression of fibrosis. Physicians should be aware of the importance of a high GGT level in patients with FALD.

Preoperative passive venous pressure-driven cardiac function determines left ventricular assist device outcomes

BACKGROUND

Right heart output in heart failure can be compensated through increasing systemic venous pressure. We determined whether the magnitude of this "passive cardiac output" can predict LVAD outcomes.

METHODS

This was a retrospective review of 383 patients who received a continuous-flow LVAD at the University of Michigan between 2012 and 2021. Pre-LVAD cardiac output driven by venous pressure was determined by dividing right atrial pressure by mean pulmonary artery pressure, multiplied by total cardiac output. Normalization to body surface area led to the passive cardiac index (PasCI). The Youden J statistic was used to identify the PasCI threshold, which predicted LVAD death by 2 years.

RESULTS

Increased preoperative PasCI was associated with reduced survival (hazard ratio [HR], 2.27; P < .01), and increased risk of right ventricular failure (RVF) (HR, 3.46; P = .04). Youden analysis showed that a preoperative PasCI ≥0.5 (n = 226) predicted LVAD death (P = .10). Patients with PasCI ≥0.5 had poorer survival (P = .02), with a trend toward more heart failure readmission days (mean, 45.09 ± 67.64 vs 35.13 ± 45.02 days; P = .084) and increased gastrointestinal bleeding (29.2% vs 20.4%; P = .052). Additionally, of the 97 patients who experienced readmissions for heart failure, those with pre-LVAD implantation PasCI ≥0.5 were more likely to have more than 1 readmission (P = .05).

CONCLUSIONS

Although right heart output can be augmented by raising venous pressure, this negatively impacts end-organ function and increases heart failure readmission days. Patients with a pre-LVAD PasCI ≥0.5 have worse post-LVAD survival and increased RVF. Using the PasCI metric in isolation or incorporated into a predictive model may improve the management of LVAD candidates with RV dysfunction.

Fontan-Associated Liver Disease: A Review

Fontan-associated liver disease (FALD) is a chronic complication of the Fontan procedure, a palliative surgery for patients with congenital heart disease that results in a single-ventricle circulation. The success of the Fontan procedure has led to a growing population of post-Fontan patients living well into adulthood. For this population, FALD is a major cause of morbidity and mortality. It encompasses a spectrum of hepatic abnormalities, ranging from mild fibrosis to cirrhosis and hepatocellular carcinoma. The pathophysiology of FALD is multifactorial, involving hemodynamic and inflammatory factors. The diagnosis and monitoring of FALD present many challenges. Conventional noninvasive tests that use liver stiffness as a surrogate marker of fibrosis are unreliable in FALD, where liver stiffness is also a result of congestion due to the Fontan circulation. Even invasive tissue sampling is inconsistent due to the patchy distribution of fibrosis. FALD is also associated with both benign and malignant liver lesions, which may exhibit similar imaging features. There is therefore a need for validated diagnostic and surveillance protocols to address these challenges. The definitive treatment of end-stage FALD is also a subject of controversy. Both isolated heart transplantation and combined heart-liver transplantation have been employed, with the latter becoming increasingly preferred in the US. This article reviews the current literature on the epidemiology, pathophysiology, diagnosis, and management of FALD, and highlights knowledge gaps that require further research.

Dyslipidemia in adults with congenital heart disease: A systematic review and meta-analysis

AIMS

Several particular characteristics of patients with congenital heart disease could affect lipid levels. The objectives of this study were: a) to analyze the prevalence of dyslipidemia in congenital heart disease patients; 2) to compare lipid levels between congenital heart disease patients and a control group.

DATA SYNTHESIS

This systematic review and meta-analysis was performed according to PRISMA guidelines (PROSPERO CRD42023432041). A literature search was performed to detect studies that have reported lipid levels or the prevalence of dyslipidemia in congenital heart disease patients. We performed a qualitative analysis (studies that reported dyslipidemia prevalence) and quantitative analysis (studies that compared lipid values between congenital heart disease patients and controls). In total, 29 observational studies involving 22,914 patients with congenital heart disease and 641,086 controls were eligible for this review. The reported presence of "hyperlipidemia" or "dyslipidemia" ranged from 14.3% to 69.9%. When studies analyzed lipid variables dichotomously between congenital heart disease patients and controls, the results were conflicting. The quantitative analysis showed that patients with congenital heart disease have lower levels of total cholesterol (MD: -18.9 [95% CI: -22.2 to -15.7]; I2 = 93%), LDL-C (MD: -10.7 [95% CI: -13.1 to -8.3]; I2 = 90%) and HDL-C (MD: -6.3 [95% CI: -7.7 to -4.9]; I2 = 95%) compared to controls.

CONCLUSIONS

The qualitative analysis showed some concerns, but the quantitative analysis indicates that congenital heart disease patients showed lower levels of total cholesterol, LDL-C, and HDL-C compared to controls. New research should be developed to clarify this relevant topic.

Biological Age in Congenital Heart Disease-Exploring the Ticking Clock

Over the past 50 years, there has been a major shift in age distribution of patients with congenital heart disease (CHD) thanks to significant advancements in medical and surgical treatment. Patients with CHD are, however, never cured and face unique challenges throughout their lives. In this review, we discuss the growing data suggesting accelerated aging in this population. Adults with CHD are more often and at a younger age confronted with age-related cardiovascular complications such as heart failure, arrhythmia, and coronary artery disease. These can be related to the original birth defect, complications of correction, or any residual defects. In addition, and less deductively, more systemic age-related complications are seen earlier, such as renal dysfunction, lung disease, dementia, stroke, and cancer. The occurrence of these complications at a younger age makes it imperative to further map out the aging process in patients across the spectrum of CHD. We review potential feasible markers to determine biological age and provide an overview of the current data. We provide evidence for an unmet need to further examine the aging paradigm as this stresses the higher need for care and follow-up in this unique, newly aging population. We end by exploring potential approaches to improve lifespan care.

Unique Pulmonary Hypertensive Vascular Diseases Associated with Heart and Lung Developmental Defects

Although pediatric pulmonary hypertension (PH) shares features and mechanisms with adult PH, there are also some significant differences between the two conditions. Segmental PH is a unique pediatric subtype of PH with unclear and/or multifactorial pathophysiological mechanisms, and is often associated with complex congenital heart disease (CHD), pulmonary atresia with ventricular septal defect, and aortopulmonary collateral arteries. Some cases of complex CHD, associated with a single ventricle after Fontan operation, show pathological changes in the small peripheral pulmonary arteries and pulmonary vascular resistance similar to those observed in pulmonary arterial hypertension (PAH). This condition is termed as the pediatric pulmonary hypertensive vascular disease (PPHVD). Recent advances in genetics have identified the genes responsible for PAH associated with developmental defects of the heart and lungs, such as TBX4 and SOX17. Targeted therapies for PAH have been developed; however, their effects on PH associated with developmental heart and lung defects remain to be established. Real-world data analyses on the anatomy, pathophysiology, genetics, and molecular biology of unique PPHVD cases associated with developmental defects of the heart and lungs, using nationwide and/or international registries, should be conducted in order to improve the treatments and prognosis of patients with these types of pediatric PH.