Investigators from the Children’s Hospital of Fudan University (CHFU), China, and the Royal Hospital for Children, Scotland, conducted a prospective cohort study to assess the incidence of spontaneous closure of ventricular septal defects (VSDs) in infants. Newborns born at 1 of 3 maternity facilities in China during the February–July 2011 study period were enrolled. All newborns received echocardiography before discharge. Newborns with a VSD also received echocardiography at 3, 6, and 12 months of age and then annually until age 7, or until spontaneous closure or surgical intervention, whichever came first. After 6 months of age, newborns with VSDs had follow-up at the Pediatric Heart Center at the CHFU, where standard of care includes surgical or interventional therapy only for infants with VSDs with clinical symptoms or presentation of left heart overload. Demographics and clinical characteristics (gender, birthweight, and gestational age) were collected at enrollment.
The primary exposure variable was VSD at birth, classified as perimembranous, muscular, or doubly committed juxta-arterial (DCJA). Size of the VSD was categorized as <4mm or ≥4mm. Muscular VSDs were further categorized into midseptal, apical, posteroinferior, and anterosuperior. The primary outcome variable was spontaneous closure of the VSD by age 7, defined as the absence of color flow mapping on echocardiography. Investigators assessed the proportion of infants with VSD, the proportion with spontaneous closure, and the time to spontaneous closure by VSD type.
There were 6,750 newborns born during the study period, all of whom received echocardiography at birth. VSDs were detected in 113 (1.67%), the majority of which were muscular (64%). One patient with a VSD was lost to follow-up.
Overall, spontaneous closure occurred in 88 of the 112 of infants with VSD who had complete follow-up data: 18 of 35 (51%) infants with perimembranous VSD, 70 of 72 (97%) infants with muscular VSD, and 0 of 6 infants with DCJA. Factors associated with persistence of VSD were perimembranous (vs muscular) site and size ≥4 mm (vs <4 mm). There was no significant difference in time to spontaneous closure among those with different types of muscular VSDs.
The investigators conclude that VSDs are uncommon and that most close spontaneously.
Dr Spar has disclosed no financial relationship relevant to this commentary. This commentary does not contain a discussion of an unapproved/investigative use of a commercial product/device.
VSDs are the most common congenital heart defect (CHD), occurring in 40% of patients with CHDs.1 Previous studies have reported a prevalence of VSDs in the population ranging from 2.5–3.9 per 1,000 live births.2,3 Spontaneous closure of VSDs can occur in up to 90% of defects, mostly with smaller defects.4 Even in those with clinically significant VSDs, closure can occur in 25% (mostly small- to medium-sized VSDs).4
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