The relationship of high plasma levels of atrial and brain natriuretic peptides with disease severity in mitral valve stenosis

Objectives: We aimed to determine plasma levels of atrial (ANP) and brain (BNP) natriuretic peptides in patients with mitral stenosis (MS), and to seek clinical and echocardiographic correlations with these peptides. Study design: Thirty-eight patients (33 females, 5 males; mean age 44 +/- 9 years) with MS and 12 healthy controls (10 females, 2 males; mean age 46 +/- 7 years) were examined by echocardiography. All the patients were in sinus rhythm. Venous blood samples were taken to measure ANP and BNP levels. Results: Compared with controls, patients with MS had significantly higher plasma ANP (6 +/- 4 ng/ml vs 45 +/- 33 ng/ml) and BNP (12 +/- 7.2 pg/ml vs 79 +/- 55 pg/ml) levels (p<0.001). Diameters of the left atrium and left atrial volume index were significantly increased (p<0.001), and early (p=0.001) and late (p=0.02) diastolic velocities measured at the lateral annulus of the mitral valve were significantly decreased in the patient group. Systolic velocities showing systolic function of the left ventricle were found similar. Increased ANP and BNP levels showed significant correlations with functional capacity (r=0.43, p=0.007 and r=0.44, p=0.006, respectively), estimated pulmonary artery systolic pressure (r=0.37, p=0.022 and r=0.39, p=0.019), and left atrial volume index (r=0.48, p=0.003 and r=0.41, p=0.015). Mitral valve area was significantly correlated only with the ANP level (r=-0.37, p=0.022). In multivariate regression analysis, left atrial volume index and estimated pulmonary artery systolic pressure were found to be independent predictors for both BNP (beta=0.32, p=0.040 and beta=0.34, p=0.030, respectively) and ANP (beta=0.40, p=0.010 and beta=0.32, p=0.040) levels. Conclusion: Our data suggest that left atrial volume index and estimated pulmonary artery systolic pressure are strongly correlated with increases in BNP and ANP levels in MS, making BNP and ANP helpful in determining the severity of MS in patients with insufficient echocardiographic data.