Right heart overload contributes to cardiac natriuretic hormone elevation in patients with heart failure.
BACKGROUND
Atrial and brain natriuretic peptides (ANP and BNP) plasma concentration increases and holds a prognostic significance in patients with left ventricular dysfunction. We assessed the hypothesis that right ventricular (RV) overload might significantly contribute to plasma elevation of cardiac natriuretic hormones in patients with heart failure.


METHODS
Forty-one patients with cardiomyopathy and depressed left ventricular (LV) function (ejection fraction, EF, <40%), underwent cardiac magnetic resonance imaging (MRI) and resting plasma determination of ANP and BNP. Nineteen healthy subjects were also studied as control group. Ventricular volumes and function were assessed by MRI.


RESULTS
In the group of patients, LVEF was 22.6+/-1.2% (controls: 61.2+/-1.3%, P<0.001, mean+/-S.E.M.), while RVEF was 48.2+/-2.5% (controls: 66.7+/-1.6%, P<0.001); LV and RV end diastolic/systolic volumes, corrected by body surface area, were 143+/-7/114+/-7 ml/m2 (controls 70+/-3/27+/-2 ml/m2, both P<0.001) and 66+/-3/37+/-4 ml/m2 (controls: 63+/-4/21+/-2 ml/m2, P<0.01 only for end-systolic volume). BNP plasma value was on average 324+/-39 pg/ml (range: 23-1280, controls 10+/-2 pg/ml), ANP value was 144+/-17 pg/ml (range: 26-534, controls 15+/-1 pg/ml). BNP positively correlated with either end-diastolic or end-systolic RV volume in patients, less with LV systolic, and not with LV diastolic volume. Moreover, a significant negative correlation was observed between BNP and either LVEF or RVEF. Conversely, ANP showed a significant correlation only with end-systolic RV volume and with both RVEF and LVEF. When multivariate stepwise linear regression analysis was applied LVEF resulted the only independent predictor for ANP plasma values (R=0.591, P<0.001), while LVEF and RV end-diastolic volume for BNP (R=0.881, P<0.001, and R=0.881, P=0.035, respectively).


CONCLUSIONS
Right heart overload contributes independently to plasma elevation of natriuretic peptides. RV involvement, which is known to independently worsen prognosis in patients with cardiomyopathy, might contribute to their established prognostic power, inducing compensatory secretion of plasma cardiac natriuretic hormones.
Passino
Claudio
C
Institute of Clinical Physiology, National Research Council, Pisa, Italy. passino@ifc.cnr.it
Maria Sironi
Anna
A
Favilli
Brunella
B
Poletti
Roberta
R
Prontera
Concetta
C
Ripoli
Andrea
A
Lombardi
Massimo
M
Emdin
Michele
M
D000368:Aged; D009320:Atrial Natriuretic Factor / Q000097:blood; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D003971:Diastole; D005260:Female; D006333:Heart Failure / Q000097:blood* / Q000503:physiopathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D045283:Natriuretic Agents / Q000097:blood*; D020097:Natriuretic Peptide, Brain / Q000097:blood; D011237:Predictive Value of Tests; D011379:Prognosis; D012107:Research Design; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D013318:Stroke Volume; D013599:Systole; D016277:Ventricular Function, Left; D016278:Ventricular Function, Right
D015415:Biomarkers; D045283:Natriuretic Agents; D020097:Natriuretic Peptide, Brain; D009320:Atrial Natriuretic Factor