Strong relationship between NT-proXNP levels and cardiac output following cardiac surgery in neonates and infants.
BACKGROUND
NT-proXNP, a new natriuretic peptide analyte, incorporates information about the concentrations of both N-terminal pro-atrial and pro-brain natriuretic peptides (NT-proANP, NT-proBNP). We aimed to investigate whether NT-proXNP is a reliable indicator of the cardiac index (CI) and the hemodynamic state in neonates and infants undergoing an open heart surgery.


METHODS
We enrolled 26 children under the age of 1 year into this prospective study. All patients underwent an elective cardiac operation with cardiopulmonary bypass (CPB) to achieve complete biventricular repair. Peri-operative hemodynamic parameters were assessed by transpulmonary thermodilution and natriuretic peptide levels were recorded.


RESULTS
The NT-proXNP level correlated significantly with the simultaneously measured NT-proANP level (r=0.60, P<0.001), but more strongly with the NT-proBNP level (r=0.89, P<0.001) and the arithmetic sum of both (r=0.88, P<0.001). NT-proXNP had a strong correlation with CI (r=-0.85, P<0.001), the stroke volume index (r=-0.80, P<0.001) and the global ejection fraction (r=-0.67, P<0.009) throughout the post-operative period. Conventionally measured parameters such as heart rate, mean arterial pressure and pulse-pressure product exhibited weaker correlations with CI than NT-proXNP. Among laboratory values, creatinine levels correlated significantly with CI (r=-0.77, P<0.001) and NT-proXNP (r=0.76, P<0.001) during the post-operative period. A post-operative NT-proXNP level of 3079 pmol/l was diagnostic for CI <3 l/min/m(2) with 89% sensitivity and 90% specificity (area under the curve: 0.91 +/- 0.05).


CONCLUSIONS
NT-proXNP is a good marker of cardiac output following pediatric cardiac surgery and might be a useful tool in the recognition of a low output state.
Breuer
T
T
Department of Pediatric Anesthesia and Intensive Care, Gottsegen György Hungarian Institute of Cardiology, Budapest, Hungary.
Skoumal
R
R
Horkay
F
F
Merkely
B
B
Ala-Kopsala
M
M
Leppäluoto
J
J
Vuolteenaho
O
O
Ruskoaho
H
H
Tóth
M
M
Székely
A
A
D015415:Biomarkers; D002302:Cardiac Output / Q000502:physiology*; D006348:Cardiac Surgical Procedures; D003404:Creatinine / Q000097:blood; D004265:DNA Helicases / Q000378:metabolism*; D004562:Electrocardiography; D005260:Female; D006330:Heart Defects, Congenital / Q000601:surgery; D006339:Heart Rate / Q000502:physiology; D006352:Heart Ventricles / Q000601:surgery; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D009687:Nuclear Proteins / Q000378:metabolism*; D011184:Postoperative Period; D011446:Prospective Studies; D011498:Protein Precursors / Q000378:metabolism; D013318:Stroke Volume / Q000502:physiology; D013815:Thermodilution; D000075924:X-linked Nuclear Protein
D015415:Biomarkers; D009687:Nuclear Proteins; D011498:Protein Precursors; D003404:Creatinine; D004265:DNA Helicases; C092332:ATRX protein, human; D000075924:X-linked Nuclear Protein