Relation of N-terminal pro-B-type natriuretic peptide to symptoms, severity, and left ventricular remodeling in patients with organic mitral regurgitation

Natriuretic peptides reflect cardiac stress and may therefore be useful in the management of patients with valvular heart disease. Data regarding these biomarkers in organic mitral regurgitation (MR) are sparse. In this study, 144 patients with moderate or severe organic MR were prospectively enrolled in an observational, multicenter study to analyze the relation of N-terminal-pro-B-type natriuretic peptide (NT-pro-BNP) to symptoms, severity of MR, and echocardiographic parameters. NT-pro-BNP levels (median 373 pg/ml, interquartile range 150 to 997) were associated with age, gender, creatinine, New York Heart Association (NYHA) functional class, atrial fibrillation, left ventricular (LV) end-systolic dimension, and the LV ejection fraction. Independent predictors of increased NT-pro-BNP levels were NYHA functional class (p = 0.003), atrial fibrillation (p = 0.005) and LV end-systolic dimension (p = 0.029). MR severity and left atrial dimension were not independently associated with NT-pro-BNP levels. NT-pro-BNP levels increased significantly with NYHA class (p >0.001) but not with MR severity (p = 0.144). NT-pro-BNP levels were significantly higher in symptomatic patients than in asymptomatic patients (582 pg/ml [interquartile range 246-1,360] vs 157 pg/ml [interquartile range 64 to 256], p >0.0001). The area under the receiver-operating characteristic curve to predict symptoms for NT-pro-BNP was 0.80 (95% confidence interval 0.71 to 0.88), which was significantly higher than for all echocardiographic variables (p >0.001 for all). In conclusion, NYHA functional class, atrial fibrillation, and LV end-systolic dimension are independent predictors of increased NT-pro-BNP levels in patients with moderate or severe organic MR. Therefore, NT-pro-BNP may be helpful in the clinical evaluation and management of patients with MR, especially when it is doubtful whether symptoms are related to MR or not.