Frequency of Elevations in Markers of Cardiomyocyte Damage in Otherwise Healthy Newborns

Myocardial damage in infancy is a risk factor for eventual cardiac disease. Given that myocardial stress is greatest during the perinatal period and that the neonatal period is when the majority of pediatric heart failure occurs, we sought to determine whether even otherwise healthy neonates might have sub-clinical myocardial damage, and if so, what characteristics might identify them. We assayed umbilical cord and neonatal serum samples from 32 normal neonates for biomarkers of myocardial injury. No neonate had clinical evidence of cardiac or other abnormalities. Serum cardiac troponin T (cTnT) was elevated in 19 of 25 (76%) cords and in 16 of 17 (94%) neonates; levels indicating myocardial infarction (≥0.2 ng/mL) were found in 2 patients (1 umbilical cord and 1 neonatal sample). Creatine kinase-MB was elevated in 6 of 16 (38%) cords and in 8 of 15 (53%) neonates. Cardiac troponin I was elevated in 11% and 17% of samples; myoglobin in 4% and 17%; and high-sensitivity C-reactive protein in 9% and 40%. Measures of myocardial injury were associated with longer hospitalization (r = 0.50, P = 0.04), non-Caucasian race (P = 0.012), lower birth weights (P = 0.014), positive maternal cervical cultures (r = 0.41, P = 0.046), and elevated high sensitivity C-reactive protein (r = 0.66, P = 0.005). In conclusion, clinically occult myocardial injury appears to occur in some healthy newborns, although whether it is pathologic or not remains to be determined

Neonatal Intensive Care Unit Length of Stay Reduction by Heart Rate Characteristics Monitoring

To examine the effect of heart rate characteristics (HRC) monitoring on length of stay among very low birth weight (VLBW; <1500 g birth weight) neonates in the HeRO randomized controlled trial (RCT). We performed a retrospective analysis of length of stay metrics among 3 subpopulations (all patients, all survivors, and survivors with positive blood or urine cultures) enrolled in a multicenter, RCT of HRC monitoring. Among all patients in the RCT, infants randomized to receive HRC monitoring were more likely than controls to be discharged alive and prior to day 120 (83.6% vs 80.1%, P = .014). The postmenstrual age at discharge for survivors with positive blood or urine cultures was 3.2 days lower among infants randomized to receive HRC monitoring when compared with controls (P = .026). Although there were trends in other metrics toward reduced length of stay in HRC-monitored patients, none reached statistical significance. HRC monitoring is associated with reduced mortality in VLBW patients and a reduction in length of stay among infected surviving VLBW infants. ClinicalTrials.gov: NCT00307333