RV Dominance and AV Valve Regurgitation in Fontan Circulation

Quick Takes

  • In patients with Fontan circulation and atrioventricular valve regurgitation, RV dominance is associated with increased risk of death or transplantation.
  • Early atrioventricular valve surgery alone was not associated with increased risk of poor outcomes.

Study Questions:

What is the impact of ventricular dominance and atrioventricular valve (AVV) operation on outcomes with a Fontan circulation and ≥ moderate AVV regurgitation?

Methods:

A retrospective review was performed using the Australian and New Zealand Fontan Registry. Propensity score matching was used to assess the impact of AVV operation before or at Fontan completion on clinical outcomes.

Results:

A total of 1,703 survivors of the Fontan operation between 1987 and 2021 were studied. Patients undergoing AVV operation were more likely to have right ventricular (RV) dominance or an atrioventricular septal defect (AVSD). Death or transplantation was significantly higher in patients who underwent AVV operation before or at Fontan completion compared with those who did not (20 years: 18% vs. 13%; p = 0.03). After propensity score matching, there was no significant difference in death or transplantation between the groups (20 years: 18% vs. 16%; p = 0.41). Only patients with RV dominance who developed ≥ moderate AVV regurgitation after Fontan operation were at increased risk of death or transplantation (hazard ratio, 2.8; 95% confidence interval, 1.4-5.3; p < 0.01). In patients with left ventricular dominance, there was no significant difference in death or transplantation between patients with ≥ moderate AVV regurgitation compared with those with < moderate regurgitation (p < 0.8).

Conclusions:

The authors concluded that RV dominance but not AVV surgery itself was associated with poor outcomes. Moderate or greater AVV regurgitation is associated with a significantly increased risk of death or transplantation, but only in patients with RV dominance.

Perspective:

Recent studies have suggested worse outcomes in patients with single ventricles of left ventricular morphology, which has been felt related to AVV regurgitation in patients with single right ventricles. This study demonstrated worse outcomes in patients with AVV regurgitation and RV dominance. Patients with RV dominance may be less able to increase their ejection fraction as compensation for AVV regurgitation, leading to worsening ventricular dilatation and AVV regurgitation. This study both confirms the importance of AVV regurgitation as a risk for poor outcomes in patients with RV dominance. A proactive approach towards intervention on AVV regurgitation may be considered, although further study is required to better clarify indications for AVV intervention in this patient population.

Clinical Topics: Arrhythmias and Clinical EP, Cardiac Surgery, Congenital Heart Disease and Pediatric Cardiology, Heart Failure and Cardiomyopathies, Invasive Cardiovascular Angiography and Intervention, Implantable Devices, EP Basic Science, Cardiac Surgery and Arrhythmias, Cardiac Surgery and CHD and Pediatrics, Cardiac Surgery and Heart Failure, Congenital Heart Disease, CHD and Pediatrics and Arrhythmias, CHD and Pediatrics and Interventions, CHD and Pediatrics and Quality Improvement, Acute Heart Failure, Heart Transplant, Interventions and Structural Heart Disease

Keywords: Atrioventricular Block, Cardiac Surgical Procedures, Dilatation, Fontan Procedure, Heart Defects, Congenital, Heart Failure, Heart Septal Defects, Heart Transplantation, Heart Ventricles, Outcome Assessment, Health Care, Stroke Volume, Tricuspid Valve Insufficiency


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