Abstract 9897: Impact of Extracorporeal Membrane Oxygenation and Cardiopulmonary Resuscitation on Norwood Procedure Outcomes: Data from the Single Ventricle Reconstruction Trail

Abstract

Background: Extracorporeal membrane oxygenation (ECMO) and cardiopulmonary resuscitation (CPR) are reported risk factors for worse outcome after the Norwood procedure (NP). The Single Ventricle Reconstruction (SVR) trial randomized infants with hypoplastic left heart syndrome to a modified Blalock-Taussig shunt (MBTS) or right ventricular to pulmonary artery shunt (RVPAS). We explored associations between ECMO and/or CPR with death and transplant. Methods: Outcomes for 549 SVR patients using the shunt in place at end of the NP (MBTS 268, RVPAS 281) were compared among: CPR alone (CPR, n=37), ECMO alone (ECMO, n=49), ECMO required to regain circulation after CPR (E-CPR, n=36) and neither CPR nor ECMO (“none”, n=427). Cox proportional hazards regression with a time-dependent group indicator was used to model time to death or transplant. The interaction of patient group and shunt type was also examined. Results: Mean follow-up was 2.7 ± 1.9 years. Gestational age, age at surgery, size of ascending aorta, presence of significant tricuspid regurgitation, systolic function and shunt type were similar among the 4 groups. Low birth weight was more common in CPR or E-CPR groups (p<.001). Patients receiving CPR, ECMO or E-CPR had a higher incidence of transplant or death (p<.0001). With adjustment for surgeon and birth weight, interaction analysis showed poorer outcome with MBTS in the “none” group but not in the E-CPR group (interaction p = .014). The hazard ratio for MBTS vs. RVPAS in E-CPR was 0.48 (95% CI 0.21, 1.11) vs. 1.54 (95% CI 1.04, 2.28) for “none”. A similar pattern was seen with ECMO (interaction p = .047). A differential effect of shunt type was not observed for CPR vs. “none” patients. Conclusions: Patients requiring CPR and/or ECMO after the Norwood procedure have significantly increased early mortality and/or transplant and remain at risk for attrition remote from the initial event. The RVPAS was not found to be superior to the MBTS in patients requiring ECMO or E-CPR.