The effect of altering haemodynamics on the plasma concentrations of natriuretic peptides in heart failure.
BACKGROUND
Natriuretic peptide levels reflect haemodynamics in patients with heart failure and may serve as biochemical markers of cardiac filling pressures. The purpose of this study was to detect differences in the kinetic profile between atrial natriuretic peptide (ANP), B-type natriuretic peptide (BNP) and their N-terminal fragments N-ANP and N-BNP, in response to rapid and persistent vasodilatation.


METHODS
Sixteen men and four women aged 63.0+/-10.4 (mean+/-S.D.) with symptomatic congestive heart failure (NYHA III) and pulmonary capillary wedge pressure (PCWP)>18 mm Hg, received a 24-h infusion of nitroglycerin (N=8) or nicorandil (N=12). A reduction of PCWP was achieved for the duration of the study. Natriuretic peptides were measured by radioimmunoassay at baseline, 1, 3, 6, 12 and 24 h.


RESULTS
PCWP and right atrial pressure fell rapidly and then increased modestly. ANP and N-ANP demonstrated a similar pattern. In contrast, BNP and N-BNP levels fell steadily throughout the observation period. This was accompanied by a continuous reduction of systemic vascular resistance (SVR). PCWP was highly correlated to the levels of all the natriuretic peptides. Using a longitudinal regression model evaluating responses over time, we found separate, significant relationships between all peptides and haemodynamic variables


CONCLUSIONS
The atrial natriuretic peptides reflect rapid changes in filling pressures while the B-type peptides respond much slower. B-type peptides are less sensitive to short-term changes in filling pressures, but should reflect changes in SVR better during vasodilator therapy.
Larsen
A I
AI
University of Bergen, Cardiology Division, Stavanger University Hospital, N-4001 Stavanger, Norway. alfil@broadpark.no
Dickstein
K
K
Ahmadi
N S
NS
Aarsland
T
T
Kvaløy
J T
JT
Hall
C
C
D002303:Cardiac Output, Low / Q000097:blood / Q000188:drug therapy*; D018592:Cross-Over Studies; D018450:Disease Progression; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D045265:Natriuretic Peptides / Q000097:blood*; D020108:Nicorandil / Q000494:pharmacology / Q000627:therapeutic use*; D005996:Nitroglycerin / Q000494:pharmacology / Q000627:therapeutic use*; D010446:Peptide Fragments / Q000097:blood / Q000187:drug effects; D011863:Radioimmunoassay; D013318:Stroke Volume / Q000187:drug effects / Q000502:physiology; D013997:Time Factors; D014661:Vasoconstriction / Q000187:drug effects; D014664:Vasodilation / Q000187:drug effects*; D014665:Vasodilator Agents / Q000494:pharmacology / Q000627:therapeutic use*
D045265:Natriuretic Peptides; D010446:Peptide Fragments; D014665:Vasodilator Agents; D020108:Nicorandil; D005996:Nitroglycerin