Surgical pathways and risk categories in the management of hypoplastic left heart syndrome and variants

The distribution of risk factors in neonates with hypoplastic left heart syndrome is heterogeneous, and their impact remains unclear. We describe the risk categories, surgical strategies, and outcomes in this population.

Retrospective chart review was performed for 233 consecutive neonates undergoing surgery for hypoplastic left heart syndrome and variants at a single center in 2006-2023. The criteria for our risk categories were determined by expert consensus, refined based on Cox regression for mortality, and applied retrospectively to a historical cohort.

Of the 233 patients with hypoplastic left heart syndrome, 75 (32%) were standard risk, 128 (55%) were intermediate risk, and 30 (13%) were high risk. A total of 212 patients (91%) underwent primary Norwood and 21 patients (9%) underwent hybrid stage 1. Surgical strategy was strongly correlated with risk category, with more hybrid stage 1 performed in higher-risk patients (P < .001). Operative mortality and mortality at last follow-up (median, 4.3 years [0.6-10.1]) were strongly correlated with risk category (1% and 8% for standard risk, 14% and 23% for intermediate risk, and 27% and 57% for high risk, respectively [P < .001 and P < .001]). High-risk patients post-2015 had comparable mortality when stratified by surgical strategy (P = .46).

The risk categories presented here effectively stratify patients by operative mortality and mortality at last follow-up and are strongly correlated with surgical strategy. These risk categories may pave the way to develop a predictive risk model to guide decision-making for patients with hypoplastic left heart syndrome.