Relationship between N-terminal pro-B-type natriuretic peptide (Nt-proBNP) and cardiac cycle efficiency in cardiac surgery.
N-terminal pro-B-type natriuretic peptide (Nt-proBNP) is a peptide released from myocardium in response to ventricular wall stress and dysfunction. Nt-proBNP plasma levels are elevated in a variety of cardiovascular disorders and are largely used for diagnosis and treatment of cardiac diseases. The cardiac cycle efficiency (CCE) is a haemodynamic variable that represents the left ventricle wall stress and the heart's effort to maintain an adequate blood flow to tissues. We investigated the relationship between Nt-proBNP and CCE values in patients undergoing cardiac surgery. Twenty-five patients undergoing aortic valve replacement were studied. Plasma Nt-proBNP concentrations were performed by electroluminescence immunoassay before starting surgery (t0), at the end of extracorporeal circulation (t1) and 3 hours after surgery (t2). CCE measurements were acquired at the same intervals and correlations with Nt-proBNP levels were calculated. Nt-proBNP plasma concentration was 1430 ± 341 pg/ml at t0, peaked significantly at t1 (2129 ± 561 pg/ml, p<0.001) and moderately decreased at t2 (1924 ± 477 pg/ml, p<0.05). A direct correlation between Nt-proBNP measured at t0 and t1 was found (r=0.91, p<0.001). Overall, a negative correlation between CCE and proBNP values was found (r=-0.89, p<0.01). Correlations between CCE and Nt-proBNP were -0.91, -0.83 and -0.88, at t0, t1 and t2, respectively (p<0.01). Nt-proBNP levels reflect the severity of left ventricle dysfunction in patients undergoing cardiac surgery. CCE correlated well with serum Nt-proBNP levels and seems to be a useful variable to monitor the left ventricular stress and recovery during the various phases of surgery.
Unit of Cardiothoracic Anaesthesia and Intensive Care, Department of Surgery and Bioengineering, University of Siena, Viale Bracci 1, 53100, Siena, Italy. scolletta@unisi.it
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Scolletta
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Ranaldi
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Carlucci
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Franchi
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Romano
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Biagioli
D000368:Aged; D000465:Algorithms; D001021:Aortic Valve / Q000601:surgery*; D001024:Aortic Valve Stenosis / Q000097:blood / Q000503:physiopathology / Q000601:surgery*; D006348:Cardiac Surgical Procedures; D004452:Echocardiography; D005260:Female; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D008297:Male; D008991:Monitoring, Physiologic / Q000379:methods*; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D010446:Peptide Fragments / Q000097:blood*; D013997:Time Factors; D016277:Ventricular Function, Left / Q000502:physiology*
D010446:Peptide Fragments; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain