Clinical Outcome Score Predicts Adverse Neurodevelopmental Outcome After Infant Heart Surgery

Abstract

Background: The purpose of this study was to determine whether a clinical outcome score derived from early postoperative events is associated with Bayley-III scores at 18 to 24 months among infants undergoing cardiopulmonary bypass surgery.

Methods: Included were infants aged 6 weeks or less who underwent surgery between 2005 and 2009, all of whom were referred for neurodevelopmental evaluation at 18 to 24 months. We excluded children with chromosomal abnormalities. The prespecified clinical outcome score had a range of 0 to 7. Lower scores indicated a more rapid postoperative recovery. Patients requiring extracorporeal life support were assigned a score of 7.

Results: One hundred and ninety-nine subjects were included. Surgical procedures were arterial switch (72), Norwood (60), repair of total anomalous pulmonary venous connection (29), and other (38). Nine subjects had postoperative extracorporeal life support. Mean clinical outcome score in the Norwood group was 4.0 ± 1.4 versus the arterial switch group (2.6 ± 1.5, p < 0.001), total anomalous pulmonary venous connection group (2.8 ± 1.8, p < 0.01), and other group (4.0 ± 1.8, p = not significant). Among children who had a clinical outcome score of 4 or greater, there was a decrease in Bayley-III cognitive score of 5.7 (95% confidence interval: 1.5 to 9.9, p = 0.009), a decrease in language score of 10.0 (95% confidence interval: 4.9 to 15.1, p < 0.001), and a decrease in motor score of 9.7 (95% confidence interval: 4.8 to 14.5, p < 0.001). Time until lactate of 2.0 mmol/L or less and highest 24-hour inotrope score increased with increasing clinical outcome score (p < 0.0001).

Conclusions: Clinical outcome scores of 4 or greater were associated with significantly lower Bayley-III scores at 18 to 24 months. This score may be valuable as an endpoint when evaluating novel potential therapies for this high-risk population.