1. 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

2. We have no disclosures.

3. 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

4. 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

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

6. 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

7. Patients and Outcomes

8. Risk Factors for Death after Norwood
Multiphase parametric risk hazard analysis

9. Outcomes after S2P

10. Progressing to S2P
months old

11. Risk Factors for Death after S2P

12. 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

13. Survival After Norwood%

14. Survival after Norwood, through S2P%

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

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

17. 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)

18. post-Norwood Survival
Optimal Timing, by WAZ
Risk-adjusted, 4-Year,
post-Norwood Survival
Weight-for-Age Z-score
at the pre-S2P cath
“Cohort average”

19. 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
Low risk
Average-risk
High risk

20. 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