title: Biomarker responses during and after treatment with nesiritide infusion in patients with decompensated chronic heart failure.
abstract: BACKGROUND
  Objective methods to assess the adequacy of medication therapy for patients with advanced heart failure are lacking. Serial measurements of biomarkers might be beneficial. Therapy guided by N-terminal pro-B-type natriuretic peptide (NT-proBNP) might be helpful because NT-proBNP should be lowered by therapies that decrease endogenous BNP secretion.
  
  
  METHODS
  NT-proBNP and BNP were measured in a nonconsecutive patient cohort receiving clinically indicated intravenous nesiritide. Blood samples were drawn before, at 6 and 24 h during, and at 6 h after infusion. A reduction in NT-proBNP was defined as a decrease from baseline during infusion ("infusion responders") of >3 SD of the variability of the assay measurement (approximately 20%). Patients with decreases >20% in both NT-pro BNP and BNP at 6 h post infusion were designated "biochemical responders".
  
  
  RESULTS
  Forty patients [27 males; mean (SE) age, 68 (2) years; mean (SE) left ventricular ejection fraction, 25 (1.4)%] were studied. All patients improved clinically. Overall, the changes in NT-proBNP were a 18 (4.6)% [mean (SE)] and 19.8% (median) decrease from baseline at 24 h of infusion and a 22 (6.0)% and 17.8% decrease at 6 h post infusion (P <0.001 compared with baseline). In a large number of patients, decreases in NT-proBNP were, however, within the variability of the assay. Subgroup analysis showed that 22 of 40 patients were infusion responders with a >20% decrease from baseline in NT-proBNP during nesiritide infusion, whereas only 12 patients were biochemical responders with >20% decreases from baseline postinfusion for both NT-proBNP and BNP.
  
  
  CONCLUSIONS
  In this study, many patients had decreased NT-proBNP and BNP values after therapy with nesiritide, but the majority of patients did not demonstrate biochemically significant decreases in analytes despite a clinical response. Until we know more about the responses of natriuretic peptides to therapies such as nesiritide, a strategy of monitoring NT-proBNP and BNP to guide therapy cannot be universally advocated.
authors.affiliation: Division of Cardiovascular Diseases and Internal Medicine, Mayo Clinic Rochester, MN 55905, USA. miller.wayne@mayo.edu
authors.forename: Wayne L
authors.initials: WL
authors.lastname: Miller
authors.forename: Karen A
authors.initials: KA
authors.lastname: Hartman
authors.forename: Mary F
authors.initials: MF
authors.lastname: Burritt
authors.forename: Daniel D
authors.initials: DD
authors.lastname: Borgeson
authors.forename: John C
authors.initials: JC
authors.lastname: Burnett
authors.forename: Allan S
authors.initials: AS
authors.lastname: Jaffe
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000097:blood; D002908:Chronic Disease; D015331:Cohort Studies; D016903:Drug Monitoring / Q000379:methods; D005260:Female; D006333:Heart Failure / Q000188:drug therapy*; D006801:Humans; D007118:Immunoassay; D007262:Infusions, Intravenous; D008163:Luminescent Measurements; D008297:Male; D020097:Natriuretic Peptide, Brain / Q000008:administration & dosage / Q000097:blood* / Q000627:therapeutic use*; D009419:Nerve Tissue Proteins / Q000097:blood*; D010446:Peptide Fragments / Q000097:blood*; D011498:Protein Precursors / Q000097:blood*; D011994:Recombinant Proteins / Q000008:administration & dosage / Q000627:therapeutic use; D016896:Treatment Outcome
chemical_list: D015415:Biomarkers; D009419:Nerve Tissue Proteins; D010446:Peptide Fragments; D011498:Protein Precursors; D011994:Recombinant Proteins; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain