Outcomes of implementing cardiac risk stratification and perinatal care recommendations for prenatally diagnosed congenital heart disease

Introduction
Prenatal diagnosis of congenital heart disease (CHD) can best achieve decreases in perinatal mortality and improvements in preoperative clinical status when combined with risk stratification and active perinatal management. This study assessed implementation of a four-tier risk classification system for prenatally diagnosed CHD based on the need for emergent neonatal cardiac intervention (ENCI), each with specific perinatal care recommendations.

Material and methods
Prenatally diagnosed fetuses with CHD were risk stratified, and fetal, perinatal and postnatal data were collected with the primary aim to assess risk stratification accuracy. Secondary aims assessed adherence to perinatal management recommendations and evaluation of outcomes compared to a non-risk stratified historical cohort.

Results
The study cohort comprised 84 patients prenatally diagnosed with CHD with assigned ENCI level. This included ENCI level 1 (n = 4), level 2 (n = 16), level 3 (n = 50), and level 4 (n = 14). Cardiac intervention was performed emergently in 8 cases (9.5%), non-emergently in neonates in 56 cases (67%), and before one year of age in an additional 15 cases (18%). Our classification system correctly risk stratified 90.4% (76/84) of infants with CHD based on their need for neonatal cardiac intervention. No ENCI level 1 or 2 risk stratified infants required neonatal intervention, and only one of the 50 ENCI level 3 cases required an unanticipated ENCI. Thus, the ENCI classification system correctly identified 98.5% (69/70) of patients who did not require emergent neonatal cardiac intervention in the first 48 hours of life. For perinatal management recommendations, the delivery notifications were appropriately sent 94% of the time, neonatology was present for 99% of recommended deliveries, and PGE was started according to recommendations in 93% (53/57) of ENCI level 3 and 4 cases. The ENCI cohort (2012-2014) compared to an earlier non-risk stratified cohort of 146 patients (2008-2011) showed no difference in survival (p = 0.66) or hospital length of stay (p = 0.19).

Conclusions
Implementation of our prenatal risk stratification system accurately predicted the need for emergent neonatal cardiac intervention, and adherence to perinatal management recommendations was high