title: Relevance of short-term variation of B-type natriuretic peptide in patients with clinically stable heart failure.
abstract: BACKGROUND
  In patients with clinically stable chronic heart failure, circulating B-type natriuretic peptide (BNP) levels may exhibit considerable variation over a period of a few days. The aim of this study was to evaluate the clinical impact of this phenomenon.
  
  
  METHODS
  In 23 patients with clinically stable mild-to-moderate systolic heart failure [median (interquartile range) 72 (64-77) years, left ventricular ejection fraction 30 (27-40)%] and a history of previous hospitalization for heart failure, BNP was measured at two time points [T1 and T2, interval 5 (3-7) days] for calculation of the absolute change in BNP concentrations between T1 and T2 (DeltaBNP; irrespective of whether there was a decrease or increase). Follow-up for rehospitalization was 436 (407-458) days.
  
  
  RESULTS
  In the group overall, DeltaBNP was 26 (9-116) pg/ml [19 (10-28)% of the value at T1]. During follow-up, 8/23 (35%) patients were rehospitalized. BNP concentrations at T1 [340 (187-533) vs. 210 (108-606) pg/ml; P = 0.33] and T2 [328 (125-491) vs. 259 (89-536) pg/ml; P = 0.51] were similar in patients who were rehospitalized and those who were not; however, DeltaBNP was higher in patients requiring rehospitalization [98 (36-186) vs. 19 (6-93) pg/ml; P = 0.04]. Patients with DeltaBNP <26 pg/ml had a longer rehospitalization-free survival than those with DeltaBNP > or = 26 pg/ml (log rank P = 0.02). Sensitivity and specificity of DeltaBNP > or = 26 pg/ml for the prediction of rehospitalization were 88% and 67% respectively.
  
  
  CONCLUSIONS
  In this small study among patients with clinically stable heart failure, higher DeltaBNP over a period of a few days was associated with a higher likelihood of rehospitalization during follow-up.
authors.affiliation: Division of Cardiology, Kantonsspital St. Gallen, Switzerland. micha.maeder@bluewin.ch
authors.forename: Micha Tobias
authors.initials: MT
authors.lastname: Maeder
authors.forename: Dietrich
authors.initials: D
authors.lastname: Hack
authors.forename: Hans
authors.initials: H
authors.lastname: Rickli
authors.forename: Hans Peter Brunner-La
authors.initials: HP
authors.lastname: Rocca
authors.forename: Walter
authors.initials: W
authors.lastname: Riesen
authors.forename: Peter
authors.initials: P
authors.lastname: Ammann
mesh_terms: D000368:Aged; D005260:Female; D006333:Heart Failure / Q000097:blood* / Q000175:diagnosis*; D006801:Humans; D008297:Male; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013223:Statistics as Topic; D013997:Time Factors
chemical_list: D020097:Natriuretic Peptide, Brain