Spontaneous closure of ventricular septal defects in newborns the first year of life
Authors: Pihl C , Norsk J , Sillesen A.S , Voegg R.O.B , Boyd H , Vejlstrup N , Axelsson A , Bundgaard H , Iversen K 
Published: November 2020

Abstract

Background
Ventricular septal defect (VSD) is one of the most common congenital heart defects. Some VSDs close spontaneously while persistence of the VSD may result in heart failure and, at long term, irreversible pulmonary hypertension. Consequently, identification of factors associated with spontaneous closure are important to ensure relevant clinical follow up of those at risk of a persistent VSD.

Purpose
We aimed to assess the rate of spontaneous closure in a population-based cohort of newborns with VSD and to identify significant predictors for spontaneous closure.

Methods
The study is part of a large-scale population-based study, focusing on cardiac structure and function, including newborns born from 1st April 2016 to 31st October 2018. Newborns with a VSDs at baseline were followed with echocardiography at 3, 6 and 12 months (+30 days) of age. Cox proportional hazard model was used to determine significant predictors of spontaneous closure

Results
Based on echocardiographies of 25.750 newborn, 850 newborns (3.3%) with a VSD were identified. The majority of newborns with VSDs were born at term (88.7%) and the mean age at inclusion was 11.7±8.1 days. VSDs were more frequent in females (57.1%, p&lt;0.001). Of all VSDs, 787l (92.6%) were of a muscular type, 60 (7.0%) of perimembranous type and 3 (0.4%) were of subarterial type. Multiple VSDs were found in 98 (11.5%) cases and all were of a muscular type. Muscular VSDs were significantly smaller than perimembranous VSDs (1.9±0.7 mm vs. 3.7±1.8 mm, p&lt;0.0001). During the follow up period, seven (0.8%) children underwent surgical repair: five (5 of 56) children with perimembranous VSDs and two (two of three) children with subarterial VSDs. Follow-up was complete in 89.4% of all children. After one year 82.6% (601 of 727) VSDs had closed spontaneously. The prevalence of VSD in one-year old children was thus 0.5%. The majority of VSD closed spontaneously during the first 6 months of life (57.6% (419/727)). Muscular VSDs showed significantly higher rate of spontaneous closure compared with perimembranous VSDs (86.9% (582 /670) vs. 46.2% (25/54), p=0.0001) during the first year of life. No subarterial VSDs closed spontaneously during follow-up. Muscular type (p=0.002), size (p&lt;0.001) and presence of one VSD as opposed to multiple (p&lt;0.0025) were associated to spontaneous closure. Sex did not significantly influence spontaneous closure rate (p=0.65).

Conclusion
In a population study including more than 25,000 newborns we found that the vast majority, i.e. almost 9/10 of all VSDs, closed spontaneously during the first year of life, ultimately resulting in a prevalence of VSD in one-year old children of 0.5%. The identified factors associated with spontaneous closure – anatomical location, size and presence of multiple VSDs are of use for future management of VSDs in newborns.

Funding Acknowledgement
Type of funding source: Other. Main funding source(s): The Danish Heart Foundation