Children Born to HIV-Positive Women at Greater Risk of Heart Abnormalities Than Other Infants, Study Says
Children born to women with HIV-1 are at greater risk of developing heart abnormalities, regardless of their HIV status, than children born to HIV-negative women, according to a study published today on the Lancet's Web site. Steven Lipshultz of the University of Rochester and colleagues compared 600 infants born to women with HIV in Houston, Boston, New York City and Los Angeles between May 1990 and January 1994 to 195 children born to women who were HIV negative. Of the infants born to women with the virus, 93 tested HIV-positive, 463 were HIV-negative and 44 were excluded from the analysis due to incomplete follow-up or death. All of the children were tested for cardiac function using echocardiography every four to six months for up to five years. HIV-positive children had a significantly higher heart rate at all ages -- averaging 10 beats per minute more than HIV-negative children born to women with HIV (Lipshultz et al., Lancet, 6/18). A faster heart rate can be "an indication of a weakened heart or abnormalities in the brain or nervous system," which regulate heart function, Lipshultz said (Wentzel, Rochester Democrat & Gazette, 6/18). Both HIV-positive children and HIV-negative children born to women with HIV had decreased low left ventricular functioning, also called low left ventricular fractional shortening, at birth through the age of eight months. At that time, HIV-negative children born to women with HIV had fractional shortening similar to children in the control group, while children with HIV continued to have fractional shortening significantly lower than children in the control group up until the age of 20 months (Lancet, 6/18). The diminished functioning of the lower left ventricle means that the children could not effectively pump oxygenated blood to their bodies (Rochester Democrat & Gazette, 6/18). Lower left ventricular mass was similar at birth for all children born to women with HIV, but became significantly higher in HIV-positive children from the ages of four to 30 months. The authors note that because cardiac dysfunction was found in both HIV-positive and HIV-negative children who were born to women with HIV, the "intrauterine environment" appears to play a role in developing heart disease. They state that this association needs outside confirmation from additional studies and theorize that HIV-1, other infections, maternal and postnatal nucleoside analogue and other drug use, maternal nutrition, placental abnormalities, racial and ethnic differences and mitochondrial dysfunction are possible candidates for the cause of cardiac impairment. They note that a report by their group concluded that zidovudine was not associated with acute or chronic cardiac abnormalities in infants exposed to the drug. Based on their findings, the authors recommend that "continuing follow-up and appropriate treatment strategies should be considered for all children born to women infected with HIV-1" (Lancet, 6/18).
Screen Children Born With HIV
In an accompanying commentary, Gregory Ensing of the University of Michigan's Congenital Heart Center writes that because congestive heart failure in association with HIV-1 has a two-year mortality rate of 75% and because decreased fractional shortening and increased left-ventricular-posterior-wall-thickness were indicators of mortality independent of CD4+ T cell count, children born with HIV should receive "repeated echocardiographic screening." However, Ensing does not endorse routine screening for all children born to women with HIV, regardless of their HIV status, because racial and postnatal nutritional differences between the study and control groups may explain the differences in cardiac function, making the need for routine screening "uncertain" (Ensing, Lancet, 6/18). However, Dr. George Sopko, a cardiologist at the National Heart, Lung and Blood Institute, which helped fund the study, said, "Children born to HIV-infected mothers need to be very carefully followed. ... The other message is that Mom needs to do everything in her power to get the best treatment there is to minimize the effect of HIV" (Rochester Democrat & Gazette, 6/18). The researchers were unable to closely match the characteristics of the external control group with the internal control group (HIV-negative children born to HIV-positive women), meaning that some of the non-significant results "could have resulted from small external control sample size" (Lipshultz et al., Lancet, 6/18). In the United States, about 6,000 HIV-positive women give birth every year, with 300 to 400 infants being born with the virus (Rochester Democrat & Gazette, 6/18).