Hybrid versus Norwood strategies for single-ventricle palliation.

BACKGROUND: Hybrid and Norwood strategies differ substantially in terms of stage II palliative procedures. We sought to compare these strategies with an emphasis on survival and reintervention after stage II and subsequent Fontan completion. METHODS AND RESULTS: Of 110 neonates with functionally single-ventricle physiology who underwent stage I palliation between 2004 and 2010, 75 (69%) infants (Norwood, n=43; hybrid, n=32) who subsequently underwent stage II palliation were studied. Survival and reintervention rates after stage II palliation, anatomic and physiologic variables at pre-Fontan assessment, and Fontan outcomes were compared between the groups. Predictors for reintervention were analyzed. Freedom from death/transplant after stage II palliation was equivalent between the groups (Norwood, 80.4% versus hybrid, 85.6% at 3 years, P=0.66). Hybrid patients had a higher pulmonary artery (PA) reintervention rate (P=0.003) and lower Nakata index at pre-Fontan evaluation (P=0.015). Aortic arch and atrioventricular valve reinterventions were not different between the groups. Ventricular end-diastolic pressure, mean PA pressure, and ventricular function were equivalent at pre-Fontan assessment. There were no deaths after Fontan completion in either group (Norwood, n=25, hybrid, n=14). CONCLUSIONS: Survival after stage II palliation and subsequent Fontan completion is equivalent between the groups. The hybrid group had a higher PA reintervention rate and smaller PA size. Both strategies achieved adequate physiology for Fontan completion. Evolution of the hybrid strategy requires refinement to provide optimal PA growth.

Shunt Failure-Risk Factors and Outcomes: An Analysis of The Society of Thoracic Surgeons Congenital Heart Surgery Database.

BACKGROUND: Systemic-to-pulmonary shunt failure is a potentially catastrophic complication. We analyzed a large multicenter clinical registry to describe the prevalence and evaluate risk factors. METHODS: Infants (aged ≤365 days) undergoing shunt operations (systemic artery-to-pulmonary artery or systemic ventricle-to-pulmonary artery) in The Society of Thoracic Surgeons Congenital Heart Surgery Database (STS-CHSD) from 2010 to 2015 were included. Multivariable logistic regression was used to evaluate risk factors for in-hospital shunt failure. Model covariates included patient characteristics, preoperative factors, procedural factors including shunt type, and center effects. Centers with more than 15% missing data for key covariates were excluded. RESULTS: Shunt operations were performed in 9,172 infants (118 centers). In-hospital shunt failure occurred in 674 (7.3%). In multivariable analysis, risk factors for in-hospital shunt failure included lower weight at operation (odds ratio [OR], 1.35; p = 0.001), preoperative hypercoagulable state (OR, 2.47; p = 0.031), and the presence of any other STS-CHSD preoperative risk factors (OR, 1.24; p = 0.038). Shunt failure was less likely with a systemic ventricle-to-pulmonary artery shunt than a systemic artery-to-pulmonary artery shunt (OR, 0.65; p = 0.020). Neither cardiopulmonary bypass nor single-ventricle diagnosis was a risk factor for shunt failure. Patients with in-hospital shunt failure had significantly higher rates of operative mortality (31.9% vs 11.1%, p < 0.001) and major morbidity (84.4% vs 29.4%, p < 0.001), and longer median postoperative length of stay among survivors (45 vs 22 days, p < 0.001). CONCLUSIONS: In-hospital shunt failure is common, and associated mortality risk is high. These data highlight at-risk patients and procedural cohorts that warrant expectant surveillance and may benefit from enhanced antithrombotic prophylaxis or other management strategies to reduce shunt failure. These findings may inform planning of future clinical trials.

Initial shunt type at the Norwood operation impacts myocardial function in hypoplastic left heart syndrome.

OBJECTIVES: We investigated the impact of initial shunt type, a Blalock-Taussig (BT) shunt versus a right ventricle to pulmonary artery conduit (RV-PA) on myocardial function at different stages of surgical palliation in patients with hypoplastic left heart syndrome (HLHS). METHODS: A population-based cohort of 63 Finnish children with HLHS (BT n = 23, RV-PA n = 40) born between 2003 and 2010 were studied retrospectively by echocardiography prior to Stages 1, 2 and 3 palliation and 0.5-3 years after Stage 3. For comparison of systolic myocardial function, we evaluated the RV fractional area change (FAC), strain, strain rate and mechanical synchrony from the apical 4-chamber view by velocity vector imaging. RESULTS: There were no intergroup differences in demographics during the study period. At baseline, no intergroup differences were detected in RV systolic myocardial function. Before Stage 2, RV FAC was higher ( P = 0.03) in the RV-PA conduit group. At Stage 3, an increase in all systolic myocardial functional parameters was observed in the BT shunt group. After Stage 3, the BT shunt group had better RV systolic function. In multiple regression analysis, the shunt type and the stage of palliation had an impact on myocardial function. CONCLUSIONS: Although patients with HLHS initially palliated with a BT shunt demonstrate lower RV FAC after Stage I, RV FAC improves after Stage 2 with better systolic performance after Stage 3 compared with those initially palliated with an RV-PA conduit.

Factors affecting death and progression towards next stage following modified Blalock-Taussig shunt in neonates.

OBJECTIVES: The modified Blalock-Taussig shunt (BTS) is utilized to palliate neonates born with restrictive pulmonary blood flow including those with single ventricle (SV) or biventricular (BV) cardiac anomalies. We aim in the current study to report palliation outcomes of neonates with BTS and to examine factors affecting death and progression to the subsequent stage of palliation or repair. METHODS: Between 2002 and 2012, 341 patients underwent BTS including 175 with SV and 166 with BV anomalies. Competing risk analysis modelled events after BTS (death or transplantation, transition to Glenn shunt or biventricular repair) and examined risk factors affecting outcomes. RESULTS: SV patients had a higher incidence of extracorporeal membrane oxygenation (ECMO) support requirement (12 vs 4%, P = 0.004) and unplanned cardiac reoperation (14 vs 7%, P = 0.051) than their BV counterparts. Additionally, hospital mortality was higher in SV than in BV patients (15 vs 3%, P < 0.001). In SV patients, competing risk analysis showed that, 2 years following BTS, 27% of patients had died or received transplantation and 73% had undergone the Glenn shunt. On multivariable analysis, factors associated with time until death or transplantation prior to Glenn were cardiopulmonary bypass [hazard ratio (HR) 3.6 (2.0-6.4), P < 0.001], unplanned cardiac reoperation [HR 2.4 (1.3-4.6), P = 0.007], pulmonary atresia [HR 2.0 (1.1-3.7), P = 0.026] and the shunt size/weight ratio [HR 1.3 (1.1-1.4) per 0.1 increase, P = 0.001]. In BV patients, competing risk analysis showed that, 2 years following BTS, 13% of patients had died or received transplantation, 85% had undergone biventricular repair and 2% were alive without biventricular repair. On multivariable analysis, factors associated with time until death or transplantation prior to biventricular repair were genetic syndromes and extracardiac malformations [HR 6.1 (2.0-18.2), P = 0.001], weight ≤2.5 kg [HR 5.6 (2.0-16.0), P = 0.001] and male gender [HR 3.4 (1.1-11.0), P = 0.041]. CONCLUSIONS: Palliation with BTS continues to be associated with significant operative morbidity and mortality. In addition to hospital death, there is an important interstage attrition risk prior to subsequent palliation or biventricular repair. Inherent patient characteristics (i.e. genetic syndromes and low weight) and anatomical details (i.e. SV, pulmonary atresia and concomitant cardiac anomalies) are associated with worse survival.