Background/ Objectives:
Congenital heart defects (CHD) affect nearly 40,000 infants in the United States each year, 25% of which have critical CHD requiring surgical intervention within the first year of life. Despite advances in the perinatal and surgical management, there continues to be high rate of mortality and significant morbidity experienced by survivors. There is a need to examine potentially modifiable risk factors for poor outcomes.
The primary objective of this study is to evaluate the in-hospital mortality and morbidity rates across different gestational ages after cardiac surgery in a single center with a dedicated neonatal cardiac ICU.
Design/Methods:
This is a retrospective, single-center cohort study. We included all neonates with critical CHD who were admitted to the neonatal cardiac ICU at Morgan Stanley Children's Hospital and had cardiac surgery between January 1, 2006-June 30, 2017. We excluded patients whose gestational age could not be determined, medical records were incomplete, or if the initial cardiac surgery were performed at another institution. Gestational age was stratified into 5 groups: 25-34 wks, 35-36 wks, 37-38 wks, 39-40 wks (referent group), and 41-42 wks gestation. Demographic and clinical characteristics were compared between groups and univariate logistic regression analyses were used to evaluate mortality and composite pre and post-operative morbidity. A negative binomial regression model and cox proportional hazards were used to evaluate postoperative duration of mechanical ventilation and length of stay.
Results:
Between January 1, 2006 -June 30, 2017 a total of 1252 neonates with critical congenital heart disease had surgery in our neonatal cardiac ICU. Of these 15 were excluded from study. Demographic data and exposure variables for the study participants are summarized in table 1. The relationship between the outcome variables of hospital mortality, pre-operative, and post-operative composite morbidity, length of mechanical ventilation, length of stay, and the gestational age groups are summarized in table 2 and 3. Compared with the referent group, only neonates born at 34 weeks gestation demonstrated a significantly increased odds of in-hospital mortality within our cohort. Infants born at 36 weeks gestation had a significantly increased odds of pre-operative morbidity. None of the gestational age groups demonstrated a statistically significant increased risk of morbidity in the post-operative. Neonates born at <37 weeks required a significantly longer period of mechanical ventilation in our cohort.
Conclusions:
Preterm birth is associated with worse outcomes after neonatal cardiac surgery. Infants born at 39-40 weeks gestation have the most optimal outcomes following neonatal cardiac surgery. We found that while prematurity remains a risk factor for early mortality, we report improved survival in this extremely high risk group within our cohort when compared to older literature.
