B-type natriuretic peptide as a marker of the effects of enalapril in patients with heart failure.
BACKGROUND
A-Type and B-type natriuretic peptides are cardiac hormones whose circulating levels reflect the severity of heart failure. It is not known how plasma levels of these hormones respond to changes in cardiac function that occur as a result of treatment with angiotensin-converting enzyme (ACE) inhibitors.


METHODS
Enalapril was administered at 5 mg/d for 3 months in 24 patients with chronic heart failure, and for the next 3 months at 15 mg/d in the high-dose group (n = 12) and 5 mg/d in the low-dose group (n = 12). We measured plasma levels of A-type or B-type natriuretic peptides, as well as conventional measures of cardiac function, such as the cardiothoracic ratio, left ventricular end-diastolic volume, and percent fractional shortening.


RESULTS
Mean (+/- SD) plasma levels of both hormones decreased promptly after 2 weeks of therapy (A-type natriuretic peptide: 140 +/- 107 pg/mL to 81 +/- 68 pg/mL, P = 0.01; B-type natriuretic peptide: 305 +/- 278 pg/mL to 190 +/- 178 pg/mL, P = 0.01). These reductions were sustained throughout therapy. In contrast, the cardiothoracic ratio, left ventricular end-diastolic dimension, and percent fractional shortening had not changed significantly after 3 months of treatment, although improvements were seen after 6 months of treatment. After 6 months, plasma levels of both A-type and B-type natriuretic peptides were significantly lower in the high-dose group than in the low-dose group (A-type natriuretic peptide: 48 +/- 25 pg/mL vs. 57 +/- 27 pg/mL, P = 0.01; B-type natriuretic peptide: 78 +/- 58 pg/mL vs. 139 +/- 61 pg/mL, P = 0.005), whereas no significant differences were observed in the other measures of cardiac function.


CONCLUSIONS
Plasma levels of A-type and B-type natriuretic peptides appear to be more sensitive markers of heart failure than conventional echocardiographic parameters and cardiothoracic ratios. Measurement of these hormones might be useful for monitoring the effects of treatment with ACE inhibitors.
Yoshimura
Michihiro
M
Department of Cardiovascular Medicine, Kumamoto University School of Medicine, Japan.
Mizuno
Yuji
Y
Nakayama
Masafumi
M
Sakamoto
Tomohiro
T
Sugiyama
Seigo
S
Kawano
Hiroaki
H
Soejima
Hirofumi
H
Hirai
Nobutaka
N
Saito
Yoshihiko
Y
Nakao
Kazuwa
K
Yasue
Hirofumi
H
Ogawa
Hisao
H
D000368:Aged; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000627:therapeutic use*; D009320:Atrial Natriuretic Factor / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D004656:Enalapril / Q000627:therapeutic use*; D005260:Female; D006333:Heart Failure / Q000097:blood / Q000188:drug therapy*; D006801:Humans; D008297:Male; D020097:Natriuretic Peptide, Brain
D000806:Angiotensin-Converting Enzyme Inhibitors; D015415:Biomarkers; D020097:Natriuretic Peptide, Brain; D004656:Enalapril; D009320:Atrial Natriuretic Factor