NT-proBNP response to dobutamine stress echocardiography predicts left ventricular contractile reserve in dilated cardiomyopathy.
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.
Parthenakis
Frangiskos I
FI
Department of Cardiology, Heraklion University Hospital, Crete, Greece.
Patrianakos
Alexandros P
AP
Haritakis
Costas N
CN
Zacharis
Evangelos A
EA
Nyktari
Eva G
EG
Vardas
Panos E
PE
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*
D002316:Cardiotonic Agents; D010446:Peptide Fragments; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain; D004280:Dobutamine