Early prognostic significance of umbilical cord troponin I in critically ill newborns. Prospective study with a control group

Abstract

To determine the value of cord blood cardiac troponin I levels (cTnl) as an early prognostic factor in critically ill newborns, and to compare cord cTnl levels with the prognostic value of the score for neonatal acute physiology (SNAP). Cord arterial samples were collected routinely for blood gas analysis, and cord venous samples for cTnl and cardiac-specific creatine kinase assay. The study group (n=109) comprised critically ill newborns who required mechanical ventilation. The control group (n = 96) comprised newborns who were either completely healthy (n = 48) or were followed in a level I neonatal care unit due to moderate-severity problems. The critically ill newborns had significantly higher cTnl levels than control babies (median [min-max] 1.4 [0-13] vs. 0 [0-1.8] ng/mL, respectively; P<0.001). In critically ill newborns, non-survivors had significantly higher cTnl levels than survivors (median [min-max] 6.6 [1.3-13.0] vs. 1.3 [0-8.0] ng/mL, respectively; P<0.001). Receiver-operator curve analysis revealed that, compared with SNAP, cTnl was a more sensitive predictor of mortality in critically ill newborns (area under curve=0.96; 95% CI=0.90-1.02). Significantly elevated cord cTnl may be a valuable predictor of mortality in critically ill newborns.