Impact of preoperative risk factors on outcomes after Norwood palliation for hypoplastic left heart syndrome

Background: Infants with hypoplastic left heart syndrome (HLHS) are susceptible to pre-Norwood comorbidities (PCs) and complications. This study aimed to describe the effect of PCs on timing and survival of Norwood palliation (NP). Methods: A single-center, retrospective review of infants with HLHS who underwent initial NP between 2003 and 2010 was performed. PCs included intact atrial septum, >= moderate atrioventricular regurgitation (AVVR), no antenatal diagnosis, mitral stenosis/aortic atresia subtype, genetic abnormality, and prematurity. Complications included pre-NP mechanical ventilation, inotropic support, infection, arrhythmia, and end-organ injury. The primary outcome measure was survival after NP. Results: 113 patients were included with 78 (69%) patients having at least one PC and 61 (78%) of those patients having at least one complication. Patients with PCs underwent NP later than those without PCs (7 vs 6 days, P = .036) as well as when associated with a complication (8 vs 5 days, P < .001). Patients with PCs had similar post-Norwood hospital length of stay (P = .116) except when the PC occurred in conjunction with a complication (28 vs 21 days; P = .015). In-hospital mortality post-NP was 10% and interstage mortality was 15%. On multivariable analysis, >= moderate AVVR was associated with increased overall mortality (OR 2.8, 95% CI 1.3-6.2). Age at NP was not associated with mortality (P = .638). Conclusions: Although PCs are common in infants with HLHS, only >= moderate AVVR was associated with increased mortality in this single-center experience. Older age at NP was not a significant risk factor for interstage mortality.