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Neonatal Outcomes in Very Preterm Infants With Severe Congenital Heart Defects: An International Cohort Study
Mikael Norman1, Stellan Håkansson2, Satoshi Kusuda3
1Department of Neonatal Medicine Karolinska University Hospital and Karolinska Institutet Stockholm Sweden.
Insights
Severe congenital heart defects (CHDs) significantly increase mortality risk in very preterm infants. These critical heart conditions are linked to higher death rates and bronchopulmonary dysplasia in vulnerable newborns.
Area of Science:
- Neonatal Medicine
- Pediatric Cardiology
- Perinatal Epidemiology
Background:
- Very preterm infants face elevated risks of mortality and severe morbidity.
- Congenital heart defects (CHDs) represent a significant concern in this high-risk population.
- Understanding the specific impact of severe CHDs on very preterm infants is crucial for risk assessment and management.
Purpose of the Study:
- To investigate the association between severe congenital heart defects (CHDs) and adverse outcomes in very preterm infants.
- To quantify the risks of mortality and specific morbidities in relation to severe CHDs.
- To analyze how different types of severe CHDs and gestational age influence these risks.
Main Methods:
- A multinational cohort study included very preterm infants (24-31 weeks gestation, <1500g birth weight) born between 2007-2015.
- Severe CHDs were identified using ICD-9 and ICD-10 codes and categorized by their physiological impact.
- In-hospital mortality was the primary outcome; neonatal brain injury, necrotizing enterocolitis, bronchopulmonary dysplasia, and retinopathy of prematurity were secondary outcomes. Adjusted and propensity score-matched analyses were performed.
Main Results:
- Infants with severe CHDs (0.77% of cohort) had a significantly higher mortality rate (18.6% vs. 8.9% in controls; OR 2.30).
- Severe CHD was associated with increased risk of bronchopulmonary dysplasia but not neonatal brain injury, necrotizing enterocolitis, or retinopathy of prematurity.
- Congestive heart failure-causing CHDs had the highest mortality risk (OR 4.96). Mortality risk for infants with CHD increased with gestational age, particularly at 31 weeks (OR 10.9).
Conclusions:
- Severe congenital heart defects are independently associated with substantially increased in-hospital mortality in very preterm infants.
- The specific type of severe CHD, particularly those causing congestive heart failure, significantly impacts mortality risk.
- Gestational age plays a role, with higher risks observed in infants closer to term among those with severe CHDs.
Abstract:
Background Very preterm infants are at high risk of death or severe morbidity. The objective was to determine the significance of severe congenital heart defects (CHDs) for these risks. Methods and Results This cohort study included infants from 10 countries born from 2007-2015 at 24 to 31 weeks' gestation with birth weights <1500 g. Severe CHDs were defined by International Classification of Diseases, Ninth Revision (ICD-9) and Tenth (ICD-10) codes and categorized as those compromising systemic output, causing sustained cyanosis, or resulting in congestive heart failure. The primary outcome was in-hospital mortality. Secondary outcomes were neonatal brain injury, necrotizing enterocolitis, bronchopulmonary dysplasia, and retinopathy of prematurity. Adjusted and propensity score-matched odds ratios (ORs) were calculated. Analyses were stratified by type of CHD, gestational age, and network. A total of 609 (0.77%) infants had severe CHD and 76 371 without any malformation served as controls. The mean gestational age and birth weight were 27.8 weeks and 1018 g, respectively. The mortality rate was 18.6% in infants with CHD and 8.9% in controls (propensity score-matched OR, 2.30; 95% CI, 1.61-3.27). Severe CHD was not associated with neonatal brain injury, necrotizing enterocolitis, or retinopathy of prematurity, whereas the OR for bronchopulmonary dysplasia increased. Mortality was higher in all types, with the highest propensity score-matched OR (4.96; 95% CI, 2.11-11.7) for CHD causing congestive heart failure. While mortality did not differ between groups at <27 weeks' gestational age, adjusted OR for mortality in infants with CHD increased to 10.9 (95% CI, 5.76-20.70) at 31 weeks' gestational age. Rates of CHD and mortality differed significantly between networks. Conclusions Severe CHD is associated with significantly increased mortality in very preterm infants.
