Society of Thoracic Surgeons 53rd Annual Meeting The Optimal Timing of Stage-2-Palliation after the Norwood Operation: A Multi-Institutional Analysis from the Congenital Heart Surgeons’ Society 8 minute presentation! Society of Thoracic Surgeons 53rd Annual Meeting January 23, 2017 JM Meza, EJ Hickey, BW McCrindle, EH Blackstone, BR Anderson, DM Overman, JK Kirklin, CA Caldarone, KJ Guleserian, RW Kim, WM DeCampli, ML Jacobs, ME Mitchell, P Chai, WG Williams, RDB Jaquiss

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Mortality during Staged Palliation Mortality remains high through single ventricle palliation Especially after the Norwood operation and prior to Stage-2- Palliation (S2P) Timing of S2P Physician modifiable Effect of timing of S2P not well understood Often due to intrinsinc patient factors that are not modifiable

Timing of S2P is a complex decision Earlier S2P Reduce volume load on systemic ventricle Eliminate shunt-associated risks Normalize coronary blood flow in those with BT shunt Normalize pulmonary vascular flow and pressure Underdevelopment of pulmonary vasculature Failure of PVR to decrease Later S2P Growth of infant and pulmonary vasculature Potentially decreased resource utilization Increased exposure to risks of Norwood-associated physiology

Hypothesis An optimal timing exists Norwood S2P Fontan ? An optimal timing exists Is based on patient-specific characteristics

Study Population Data Source = CHSS Critical Left Ventricular Outflow Tract Obstruction Registry Neonate ≤ age 30 days at admission to a CHSS institution 2005 onward AV & VA concordance Precludes an adequate systemic cardiac output through the aortic valve Study inclusion criteria Initial post-natal intervention = Norwood operation

Patients and Outcomes

Risk Factors for Death after Norwood Multiphase parametric risk hazard analysis

Outcomes after S2P

Progressing to S2P 1.7-17.2 months old

Risk Factors for Death after S2P

Analyzing Staged Procedures Norwood S2P 4 Years Model 1 Model 2 Parametric conditional survival analysis CS = S(t|s) = S(4 years | S2P) Analysis of Timing 4-year survival vs. age at S2P

Survival After Norwood %

Survival after Norwood, through S2P %

Survival through S2P Probability of Survival Months since Norwood Survival at 4 years = 71±5% Probability of Survival COHORT AVERAGE Months since Norwood

post-Norwood Survival Optimal Timing, by Age Risk-adjusted, 4-Year, post-Norwood Survival Age at S2P (months) “Cohort average”

Optimal Timing, by Age Across various risk profiles Low risk Average-risk Risk-adjusted, 4-Year, post-Norwood Survival High risk Age at S2P (months)

post-Norwood Survival Optimal Timing, by WAZ -5 -4 -3 -2 -1 0 1 2 3 4 5 Risk-adjusted, 4-Year, post-Norwood Survival Weight-for-Age Z-score at the pre-S2P cath “Cohort average”

Optimal Timing, by WAZ Across various risk profiles Risk-adjusted, 4-Year, post-Norwood Survival Weight-for-Age Z-score at the pre-S2P cath -5 -4 -3 -2 -1 0 1 2 3 4 5 Low risk Average-risk High risk

Clinical Implications Low- and average-risk infants Develop or modification of protocols Reduce variability across centers High-risk infants Does not rescue - survival especially poor with early S2P No age/weight changes risk profile Early referral for heart transplantation may maximize survival