Microarray results have limited value in predicting immediate post-operative outcomes in neonates and infants with congenital heart defects in the cardiac intensive care unit, but children with copy number variants should be included in future CHD research.
Key Findings
Results
Of 304 infants included in the study, 108 (35.5%) had abnormal microarray results and 196 (64.5%) had normal microarray results.
Of 412 total infants with surgical admissions to the CICU between 2014 and 2019, 43 were excluded for no longitudinal follow-up and 65 for no microarray results.
The study was a single-center retrospective cohort study covering admissions from 1 January 2014 to 31 December 2019.
Both normal and abnormal microarray groups had similar distributions of gestational age and birth weight.
Results
Fundamental diagnoses and primary procedures differed significantly between the normal and abnormal microarray groups.
The difference in fundamental diagnoses and primary procedures between groups was statistically significant (p < 0.005).
STS score, deep hypothermic circulatory arrest (DHCA) time, and bypass time were each significantly lower in children with abnormal microarrays than in those with normal microarrays across the study.
The lower STS scores in the abnormal microarray group suggest these patients underwent less complex cardiac surgeries overall.
Results
Patients with abnormal microarray results had a higher incidence of gastrostomy (G)-tube placement during their lifetime compared to infants with normal microarrays.
G-tube placement was identified as a longitudinal outcome through chart review.
This finding represents one of the few outcome measures where the abnormal microarray group showed a worse result compared to the normal microarray group.
G-tube placement reflects longer-term feeding difficulties, which may be associated with underlying genetic conditions identified on microarray.
Results
In the subgroup analysis of infants requiring cardiac surgery within 30 days of life, there were no detectable differences in surgical and PCICU outcomes between normal and abnormal microarray groups.
This finding held despite significant differences in fundamental diagnoses and primary procedures between the two groups within this subgroup.
Wilcoxon rank-sum and chi-square tests were used to compare outcomes between groups.
Outcomes compared were those defined and collected in the PC4 registry.
Results
DHCA time was significantly lower in the abnormal microarray subgroup in the second subgroup analysis involving specific cardiac diagnoses.
The second subgroup analysis compared normal and abnormal microarray groups in children presenting with VSD, AVSD, aortic stenosis (AS), or Tetralogy of Fallot (TOF).
DHCA time being lower in the abnormal microarray group is consistent with the overall study finding that this group underwent less complex procedures.
The specific diagnoses included in this subgroup (VSD, AVSD, AS, TOF) represent some of the more common congenital heart defects.
Conclusions
Abnormal microarray results did not predict worse immediate post-operative outcomes in the cardiac intensive care unit for neonates and infants with congenital heart defects.
The study queried both the Society of Thoracic Surgery (STS) and Pediatric Cardiac Critical Care (PCICU) registries (PC4) for outcome data.
Despite at least 33% of CHD-affected infants estimated to have genetic defects, the prognostic power of microarray screening for immediate outcomes was found to be limited.
The authors conclude that 'microarray results have limited value in predicting immediate post-operative outcomes.'
What This Means
This research examined whether abnormal genetic test results (specifically microarray tests, which detect extra or missing segments of DNA called copy number variants) could predict how sick babies with heart defects would do after heart surgery. The researchers looked at 304 infants who had heart surgery at a single hospital between 2014 and 2019, comparing outcomes between those who had normal versus abnormal genetic test results. They found that while the two groups differed in the types of heart defects they had and the types of surgeries they received, the abnormal genetic test group actually underwent less complex surgeries overall, as measured by lower surgical risk scores and shorter times on bypass machines.
The key practical finding was that having an abnormal microarray result did not predict worse outcomes in the cardiac intensive care unit immediately after surgery. Even when the researchers looked specifically at the sickest newborns (those needing surgery within the first 30 days of life) or at specific heart defect types, there were still no meaningful differences in post-surgical outcomes between the genetic groups. The one notable longer-term difference was that children with abnormal microarray results were more likely to need a feeding tube (gastrostomy tube) at some point in their lives, suggesting ongoing feeding difficulties related to their underlying genetic conditions.
This research suggests that while genetic testing is now standard practice for babies with heart defects, the results of microarray tests may not be particularly useful for predicting how a child will do in the immediate aftermath of heart surgery. However, the authors emphasize that children with copy number variants should still be included in future research on congenital heart disease, as genetic factors may influence longer-term outcomes beyond the immediate surgical recovery period that this study was able to capture.
Devine D, Tien A, He H, Baust T, Ghassemzadeh R, Lin J. (2026). Genetic Variation and Association with Post-Operative Outcomes for Neonates and Infants in the Cardiac Intensive Care Unit.. Genes. https://doi.org/10.3390/genes17080910