Risk factors for death or heart transplantation in single ventricle physiology (tricuspid atresia, pulmonary atresia and heterotaxy) a systematic review and meta-analysis

BACKGROUND: In this study we sought to evaluate risk factors (RFs) for death or heart transplantation (D-HT) in single-ventricle (SV) physiology due to tricuspid atresia (TA), pulmonary atresia‒intact ventricular septum (PA-IVS), and heterotaxy with SV (HX), clinical conditions for which outcome data are limited. METHODS: To conduct a systematic review, we included citations that evaluated occurrence of D-HT in SV physiology of TA, PA-IVS, and HX in English articles published between January 1998 and December 2017 based on inclusion and exclusion criteria, following the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. The Cochrane Risk of Bias in Non-Randomized Studies-Interventions (ROBINS-I) tool for non-randomized studies was used to assess the risk of bias. Meta-analysis was performed if RF data were available in more than 3 studies. RESULTS: Of 11,629 citations reviewed, 30 met inclusion criteria. All 30 were observational, retrospective studies. In all, 1,770 patients were included, 481 died and 21 underwent HT (63 lost to follow-up); 723 patients reached Fontan completion. We found that systemic ventricular dysfunction (odds ratio [OR] 20.7, confidence interval [CI] 10.0–42.5, I 2 = 0%) and atrioventricular valve regurgitation (AVR) were associated with risk of D-HT (OR 3.7, CI 1.9–6.9, I 2 = 14%). RF associations with D-HT could not be derived for right ventricle‒dependent coronary circulation, pulmonary arteriovenous malformations, total anomalous pulmonary venous return, arrhythmias, and pulmonary atresia. CONCLUSIONS: This systematic review and meta-analysis has identified a high mortality rate in children born with non-HLHS SV heart disease and points to potential under-utilization of HT. Systemic ventricular dysfunction and AVR were identified as RFs for D-HT in this subset of patients SV with TA, PA-IVS, and HX.