B-type natriuretic peptide for diagnosis and treatment of congestive heart failure.
BACKGROUND
Prognostic classification of congestive heart failure (CHF) is difficult and only possible with the help of additional diagnostic tools. B-type natriuretic peptide (BNP) has been used as a diagnostic and prognostic marker for patients (pts) with CHF. In this study, the clinical value of BNP for stratification and treatment of pts with CHF was evaluated.


METHODS
33 out-pts with CHF (age 57 +/- 12 years) were included. Left-ventricular (LV) ejection fraction (EF) was 27 +/- 8% (mean +/- SD) and NYHA-class 2.4 +/- 0.7. Following parameters were measured: BNP and sodium from blood samples, exercise performance from 6-minute walking test (6MWT, meters) (n = 18), LV end-diastolic diameter (LVEDD) and LV mass (LVM) from 2D-echocardiography (n = 33), as well as LV end-diastolic pressure (LVEDP, n = 23) and systemic vascular resistance (SVR, n = 20) from heart-catheterisation. Ten pts were hospitalised in the preceding 6 months because of worsening CHF or for optimisation of medical therapy. BNP was measured at the beginning and end of the hospital-stay. Follow-up was for 1 year.


RESULTS
Pts with a high NYHA-class had a higher BNP (pg/ml) than those with a low NYHA- class: NYHA I 51 +/- 20, II 281 +/- 223, III 562+/-346 and IV 1061 +/- 126 pg/ml (p = 0.002). BNP correlated with LVEDP (r = 0.50, p <0.02), SVR (r =0.49, p <0.03) and inversely with 6MWT (r =-0.60, p <0.009), LVEF (r = -0.49, p <0.004) and sodium (r = -0.36, p = 0.04). In the hospitalised pts, mean BNP (pg/ml) was 881 +/- 695 at admission,and 532 +/- 435 at discharge (n.s.). Decrease in BNPduring hospitalisation paralleled weight-loss and was significantly greater in patients with >1000 pg/ml BNP at admission (n = 5) as compared to the 5 patients with BNP <1000 (p <0.03). Patients with an adverse event during 1-year follow-up had significantly higher BNP both at steady-state (603 +/-359 pg/ml) and at time of decompensation than patients with a favourable outcome (227 +/- 218 pg/ml,p <0.001).


CONCLUSIONS
BNP correlates well with the clinical severity of CHF (NYHA-class) and is directly related to filling pressure (LVEDP), LV function(LVEF) and exercise performance (6 MWT). Furthermore, BNP has prognostic impact with regard to adverse clinical events.
Kuster
Gabriela M
GM
Swiss Cardiovascular Center, Institute of Clinical Chemistry, University Hospital, Bern, Switzerland.
Tanner
Hildegard
H
Printzen
Gert
G
Suter
Thomas M
TM
Mohacsi
Paul
P
Hess
Otto M
OM
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D009320:Atrial Natriuretic Factor / Q000097:blood* / Q000627:therapeutic use*; D002316:Cardiotonic Agents / Q000097:blood* / Q000627:therapeutic use*; D015331:Cohort Studies; D005080:Exercise Test; D005500:Follow-Up Studies; D006333:Heart Failure / Q000097:blood* / Q000188:drug therapy* / Q000503:physiopathology; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain; D017063:Outcome Assessment, Health Care; D019095:Point-of-Care Systems; D015203:Reproducibility of Results; D018570:Risk Assessment; D012720:Severity of Illness Index
D002316:Cardiotonic Agents; D020097:Natriuretic Peptide, Brain; D009320:Atrial Natriuretic Factor