Are We Getting Better?: Ongoing Challenges of Atrioventricular Valve Repair in Children With Single Ventricle Physiology.

Background: This study aimed to assess impact of atrioventricular valve (AVV) regurgitation onset, timing of AVV repair (AVVr), ventricular morphology, and era effect on AVVr outcomes in a single ventricle population.

Methods: A retrospective review of 155 patients with single ventricle physiology who underwent AVVr between 1998 and 2022 was conducted. Transplant-free survival, discharge alive, and AVV reoperation were assessed using the Kaplan-Meier survival method, stratified by the timing of AVVr (Group1 [G1], prebidirectional cavopulmonary shunt, N=33; G2, at or post-shunt, N=93; G3, at or post-Fontan, N=29). Cox proportional hazard models were used to assess the association of the timing of AVVr with death or transplant.

Results: Transplant-free survival at 10 years was lowest in G1 (G1, 16% [95% CI, 4%-35%]; G2, 65% [95% CI, 53%-74%]; G3, 85% [95% CI, 65%-94%], <0.001). In the multivariate analysis, AVVr prebidirectional cavopulmonary shunt was an independent risk factor for failure to be discharged alive (<0.001) but not for overall survival (=0.12). Meanwhile, the likelihood of discharge alive improved over the period in the entire cohort (<0.001), and right ventricle morphology (=0.02) and weight <5 kg (<0.01) at AVVr were significantly associated with death. In the multistate model, persistent or recurrent AVV regurgitation and ventricular dysfunction post-sAVVr were significantly associated with death, with hazard ratios of 3.8 (95% CI, 2.0-7.3, <0.001) and 32 (95% CI, 13-77, <0.001), respectively.

Conclusions: Patients with single ventricles who required AVVr, particularly before bidirectional cavopulmonary shunt, have poorer transplant-free survival with no meaningful improvement over the past 2 decades. Small weight and morphologic right ventricle were strongly associated with increased mortality. Alternative treatment strategies should be considered for this high-risk subgroup.