Inferior Vena Cava Diameter Predicts Nephropathy in Patients Late After Fontan Palliation

Area of Science:

• Pediatric Cardiology
• Nephrology
• Congenital Heart Disease

Background:

• Fontan palliation improves survival for single ventricle congenital heart defect patients.
• These patients face long-term risks of nephropathy, evidenced by microalbuminuria.

Purpose of the Study:

• To determine if echocardiographic measures of indexed inferior vena cava diameter (iIVC) or cardiac index (CI) can predict nephropathy in Fontan patients.
• To investigate the relationship between iIVC, CI, and abnormal microalbumin-creatinine ratio (MCR).

Main Methods:

• A single-center case-control study involving 39 asymptomatic Fontan patients and 29 healthy controls.
• Echocardiographic measurements of iIVC and CI were performed.
• Abnormal MCR in first-morning void urine was the primary outcome.

Main Results:

• 33% of Fontan patients had abnormal MCR.
• Mean iIVC was significantly larger in Fontan patients compared to controls (p < 0.0001).
• A strong positive correlation (r=0.62; p < 0.001) was found between MCR and iIVC. All patients with abnormal MCR had iIVC > 1 cm/m².
• No significant relationship was observed between CI and MCR.

Conclusions:

• Nephropathy is prevalent in Fontan survivors, necessitating screening.
• Echocardiographic iIVC measurement is a potential screening tool for nephropathy.
• An iIVC > 1 cm/m² warrants further renal evaluation in Fontan patients.