title: NT-proBNP response to dobutamine stress echocardiography predicts left ventricular contractile reserve in dilated cardiomyopathy.
abstract: BACKGROUND
  Brain natriuretic peptide (BNP) and left ventricular (LV) inotropic reserve are major prognostic indexes in heart failure (HF).
  
  
  OBJECTIVE
  To investigate the relationship between N-terminal-proBNP (NT-proBNP) changes in response to dobutamine stress echocardiography (DSE) and the LV inotropic reserve, in HF patients with dilated cardiomyopathy (DC).
  
  
  METHODS
  We studied 41 patients with DC, LVEF 31.6+/-7.7%, NYHA class II-III and 15 controls. Plasma NT-proBNP levels were measured before and 60 min after three 5-min stages of dobutamine (5 to 15 microg/kg/min).
  
  
  RESULTS
  Based on NT-proBNP changes in response to dobutamine, patients were categorized into two groups: In Group A circulating NT-proBNP levels fell (-16.6+/-7.8%), and in Group B they increased (8.4+/-9.1%). Group A had a marked improvement in WMSI compared to Group B (32.1+/-9.7% vs. 18.8+/-15.9%, p<0.001). Multivariate analysis showed that NT-proBNP changes were an independent predictor of LV inotropic reserve (b= -0.55, p<0.001). A reduction of 21.3% in plasma NT-proBNP levels in response to dobutamine predicted an improvement in WMSI of >25% with a sensitivity of 100% and a specificity of 92.3%.
  
  
  CONCLUSIONS
  NT-proBNP changes in response to dobutamine reflect improvement in LV contractility and constitute an independent predictor of LV inotropic reserve in patients with DC.
authors.affiliation: Department of Cardiology, Heraklion University Hospital, Crete, Greece.
authors.forename: Frangiskos I
authors.initials: FI
authors.lastname: Parthenakis
authors.forename: Alexandros P
authors.initials: AP
authors.lastname: Patrianakos
authors.forename: Costas N
authors.initials: CN
authors.lastname: Haritakis
authors.forename: Evangelos A
authors.initials: EA
authors.lastname: Zacharis
authors.forename: Eva G
authors.initials: EG
authors.lastname: Nyktari
authors.forename: Panos E
authors.initials: PE
authors.lastname: Vardas
mesh_terms: D000368:Aged; D002311:Cardiomyopathy, Dilated / Q000097:blood* / Q000000981:diagnostic imaging*; D002316:Cardiotonic Agents / Q000494:pharmacology; D004280:Dobutamine / Q000494:pharmacology; D025401:Echocardiography, Stress; D005260:Female; D006333:Heart Failure / Q000097:blood / Q000000981:diagnostic imaging; D006801:Humans; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction / Q000187:drug effects*; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D010446:Peptide Fragments / Q000097:blood*
chemical_list: D002316:Cardiotonic Agents; D010446:Peptide Fragments; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain; D004280:Dobutamine