Clinical Characteristics and Outcome of Incidental Atrial Septal Openings in Very Low Birth Weight Infants

Abstract

Background: Atrial septal openings (ASOs) are very common in premature infants. Objective: The study aimed to evaluate the prevalence and natural course of ASOs in very low birth weight (VLBW) infants diagnosed in the first week of life and the association of ASOs with various clinical factors. Methods: We retrospectively reviewed the medical records of 217 infants born with a weight of <1,500 g between January 2007 and December 2011. Echocardiography was conducted within the first week of life in all infants. Clinical factors were compared between infants with ASO and those with an intact atrial septum. ASO closure was confirmed by echocardiography at the 3-month follow-up and subsequently every 6 months. Results: The incidence of ASOs was 40.3% in VLBW infants. Patent ductus arteriosus (PDA) was associated with a higher incidence of ASO in a multivariate analysis (OR 4.005, 95% CI 2.015-7.960, p < 0.001), and PDA was a predictor of early ASO closure. The rate of oxygen requirement for at least 28 days was higher in infants with ASO, whereas oxygen dependency at 36 weeks' postmenstrual age did not differ between the infant groups. The mean time of closure was 5.8 ± 7.1 months of age (range 0-36). All followed infants showed spontaneous closure within 3 years. Conclusions: ASOs occur at a relatively high incidence in VLBW infants, but most of these close spontaneously within 3 years. PDA was predictive of ASO at the first echocardiography but did not delay ASO closure. The ASOs in VLBW infants were not a significant cause of concern.