Usefulness of the brain natriuretic peptide to atrial natriuretic peptide ratio in determining the severity of mitral regurgitation.
BACKGROUND
Atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) levels were characterized in subjects with mitral regurgitation (MR).


METHODS
Sixty-two cases of moderate or severe chronic MR were studied. The blood levels of neurohormonal factors were stratified by the known MR prognostic factors of New York Heart Association (NYHA) functional class, left ventricular end-diastolic diameters, left ventricular end-systolic diameter (LVDs), ejection fraction (EF), left atrial diameter and presence of atrial fibrillation (AF).


RESULTS
ANP levels were higher in NYHA class II and lower in classes I and III/IV (P=0.0206). BNP levels were higher in NYHA class II than class I (P=0.0355). The BNP/ANP ratio was significantly higher in NYHA classes II and III/IV than in class I (P=0.0007). To differentiate between NYHA classes I/II and III/IV, a cut-off BNP/ANP ratio of 2.97 produced a sensitivity of 78% and specificity of 87%. Compared with subjects in sinus rhythm, patients with AF had an enlarged left atrium and lower ANP levels. The BNP/ANP ratio correlated significantly with left atrial diameter, LVDs and EF (r=0.429, P=0.0017; r=0.351, P=0.0117; and r=-0.349, P=0.0122; respectively), and was significantly higher among all the known operative indications for MR tested (LVDs 45 mm or more, EF 60% or less, NYHA class II or greater and AF; P=0.0073, P=0.003, P=0.0102 and P=0.0149, respectively).


CONCLUSIONS
In chronic MR, levels of ANP and BNP, and the BNP/ANP ratio are potential indicators of disease severity.
Shimamoto
Ken
K
Department of Cardiology, Tokyo Women's Medical University, Aoyama Hospital, Tokyo, Japan.
Kusumoto
Miyako
M
Sakai
Rieko
R
Watanabe
Hirota
H
Ihara
Syunichi
S
Koike
Natsuka
N
Kawana
Masatoshi
M
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D009320:Atrial Natriuretic Factor / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D005260:Female; D006333:Heart Failure / Q000097:blood; D006801:Humans; D008297:Male; D008875:Middle Aged; D008944:Mitral Valve Insufficiency / Q000097:blood* / Q000175:diagnosis; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D011237:Predictive Value of Tests; D012107:Research Design; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index
D015415:Biomarkers; D020097:Natriuretic Peptide, Brain; D009320:Atrial Natriuretic Factor