Defining diastolic dysfunction post-Fontan: Threshold, risk factors, and associations with outcomes

Area of Science:

• Cardiology
• Pediatric Cardiology
• Congenital Heart Disease

Background:

• Patients with single ventricle physiology post-Fontan procedure face high risks of diastolic dysfunction (DD) and elevated end-diastolic pressure (EDP).
• Early identification and management of DD are crucial for improving long-term outcomes in this population.

Purpose of the Study:

• To establish the optimal EDP threshold indicative of adverse outcomes following the Fontan procedure.
• To identify clinical and imaging predictors associated with the development of DD in Fontan patients.

Main Methods:

• Utilized data from the Fontan Outcome Registry using Cardiac Magnetic Resonance Examinations (FORCE).
• Included patients who underwent cardiac catheterization and cardiac magnetic resonance (CMR) within a two-year window.
• Defined a composite outcome including mortality, arrhythmias, plastic bronchitis, protein-losing enteropathy, or transplant listing.

Main Results:

• Analyzed 861 patients (mean age 16.4 ± 9.3 years); DD was defined at an optimal EDP threshold >13 mm Hg.
• Diastolic dysfunction (DD) was present in 11.3% of patients and was associated with a >3-fold increased risk of adverse outcomes (HR 3.37).
• Predictors of DD included older age at catheterization, higher BMI, non-left ventricular morphology, and larger ventricular end-diastolic volume (EDV).

Conclusions:

• Elevated EDP >13 mm Hg signifies diastolic dysfunction (DD) and is linked to a significantly higher risk of adverse outcomes post-Fontan.
• Older age, higher BMI, non-left ventricular morphology, and increased EDV are key risk factors for DD.
• Screening catheterization in patients with risk factors may aid in early DD detection and tailored management strategies.