LSM by VCTE in Post-Fontan Patients

Cuadros, et al. Role of transient elastography in the diagnosis and prognosis of Fontan-associated liver disease.

The Fontan procedure serves as the primary palliative surgical intervention for enhancing survival in patients with congenital heart disease and single-ventricle physiology. Post-surgical hemodynamic alterations cause splanchnic congestion and reduced pulsatility, leading to hepatic congestion and subsequent chronic liver disease, portal hypertension, and associated complications.

VCTE represents a particularly valuable approach for post-Fontan patients, given the increased procedural risks associated with invasive liver assessment in this population.

The objective of this study was to evaluate the relationship between LSM by VCTE and FALD, establish diagnostic cut-off values for FALD and advanced FALD, and assess the correlation between LSM and clinically significant outcomes.

Retrospective single-center study (Hospital Universitario La Paz, Madrid)
Included 91 post-Fontan patients of >18 years

Study period: Jan 2017 – Nov 2023

Median LSM was significantly higher in patients with FALD than in those without (27.7 vs 14.6 kPa, P < 0.05), and higher in advanced FALD compared to non-advanced FALD (29.5 vs 19.0 kPa, P < 0.05).

LSM by VCTE correlated with clinically relevant events (OR = 1.07; 95% CI: 1.01–1.13; P = 0.021) and all-cause mortality (OR = 1.23; 95% CI: 1.02–1.47; P = 0.026).

FALD cut-off values:

• Optimal: 20 kPa (sensitivity 92.3%; specificity 80%)
• Rule-out: 15 kPa (sensitivity 96.9%)
• Rule-in: 25 kPa (specificity 100%)

Advanced FALD cut-off values:

• Optimal: 25 kPa (sensitivity 69.6%; specificity 68.4%)
• Rule-out: 20 kPa (sensitivity 95.7%)
• Rule-in: 40 kPa (specificity 94.8%)

Clinical Algorithm Developed based on LSM by TE and elapsed time since Fontan surgery (See Figure 2):

• LSM < 15 kPa: No FALD
• LSM ≥ 25 kPa: FALD present
• LSM 15-25 kPa: Consider time since surgery (< 10 years = no FALD, > 10 years = FALD present)
• Rule-in and rule-out FALD: AUROC, 0.877; sensitivity, 95.4%; specificity, 80%; PPV, 96.9%; NPV, 72.7%; accuracy, 93.3%

Figure 2 – Fontan-associated liver disease algorithm based on the liver stiffness measurement by transient elastography and elapsed time

These results indicate that most patients’ post-Fontan surgery develop liver damage, highlighting the importance of monitoring FALD and its complications in patient management.

FALD is primarily due to sinusoidal congestion rather than necroinflammation. Therefore, traditional scores like APRI and FIB-4, which rely on cytolytic enzymes, may be less appropriate.

VCTE is useful for prognosis in patients with FALD with specific cut-off values and based on elapsed time since Fontan surgery.

In adult post-Fontan patients, FibroScan serves as an effective non-invasive tool for diagnosing Fontan-associated liver disease. The correlation between liver stiffness measurements and major clinical outcomes demonstrates its prognostic value in this patient population.