Subclinical myocardial injury in small-for-gestational-age neonates

Abstract

Objective: Small-for-gestational-age (SGA) infants are at risk for premature death from cardiovascular disease (myocardial infarction and stroke), hypertension, and diabetes in adult life. Severeintrauterine growth restriction is often associated with subclinical cardiovascular abnormalities detectable during fetal echocardiography. The objective of this study was to determine whether SGA newbornshave evidence of myocardial injury at birth.Study design: Cardiac troponin I, a specific marker of myocardial injury widely used for the diagnosis of myocardial infarction in adults, was determinedin umbilical cord blood. Umbilical cord venous blood was obtained at the time of birth from 72 SGA newborns (birth weight below the 10th centile for gestational age) and 309 newborns whose birth weightswere appropriate for gestational age (AGA). Cardiac troponin I was determined with a commercially available immunoassay (sensitivity 0.2 ng/ml) employed in clinical laboratories (Immulite 2000, DiagnosticProducts Corp., Los Angeles, CA).Results: Cardiac troponin I was not detectable in any of the blood samples from AGA infants. In contrast, 4.2% (3/72) of SGA infants had detectable cardiac troponinI in umbilical cord blood (Fisher's exact test, p = 0.007).Conclusion: A subgroup of SGA newborns undergoes myocardial injury before birth. This insult may predispose to the developmentof adult premature cardiovascular disease and death.