NEW YORK (Reuters Health) - Infants born with a congenital heart defect that goes uncorrected have a much greater risk of dying than their counterparts who have the heart defect corrected, suggest results of a new study.

The birth heart defect known as patent ductus arteriosus, or PDA, afflicts mainly infants who are born very prematurely. The defect occurs when a large blood vessel near the heart -- the ductus arteriosus -- fails to close at birth. The condition leads to abnormal blood flow between the aorta and pulmonary artery, two major blood vessels surrounding the heart.

Because the standard of care has been to attempt to close the PDA in preterm infants, there is little information on the outcome of infants with a persistently open ductus arteriosus.

Dr. Shahab Noori from University of Oklahoma, Oklahoma City and colleagues examined the possible impact of the failure to close the PDA on death in 301 infants who were born prematurely weighing 1500 grams or less.

"Basically what we found was that preterm infants whose ductus arteriosus failed to close either spontaneously or with medication had an eight-fold increase in risk of dying during the initial hospital stay," Noori told Reuters Health.

In the January 2009 issue of Pediatrics, the investigators point out that the 41 infants with a persistently open ductus arteriosus had lower birth weight and were less mature than the 260 infants with a closed ductus arteriosus.

According to the clinicians, the "unadjusted" death rate was 70 percent in infants with an open ductus arteriosus versus 11 percent in those with a closed ductus arteriosus.

"The increased odds of mortality was noted even when known risk factor for death such as degree of prematurity and infection were taken into account," Noori said.

"Although our study does not establish the patent ductus arteriosus as the cause of increased mortality, it strongly raises this possibility," Noori concluded.

SOURCE: Pediatrics, January 2009.

• More News on Congenital Heart Defects
• More News on Premature Babies

Related MedlinePlus Pages:

• Congenital Heart Defects
• Premature Babies