Association of B-Type Natriuretic Peptide Activation to Left Ventricular End-Systolic Remodeling in Organic and Functional Mitral Regurgitation

B-type natriuretic peptide (BNP) is activated with mitral regurgitation (MR), but it is unclear whether BNP activation is uniform in organic and functional MR and whether it merely reflects symptoms or is a biomarker of left ventricular (LV) geometric and functional alterations. Comprehensive Doppler echocardiography and hormonal measurements were performed prospectively in 99 patients, 50 with organic MR, 28 with functional MR (with similar LV enlargement 130 ± 21 vs 141 ± 40, p = 0.18, and age 64 ± 13 vs 66 ± 12 years, p = 0.56) and 21 controls subjects of similar age. Compared with the controls, the patients with MR displayed LV remodeling and BNP activation. In those with functional MR compared with those with organic MR, despite a lower regurgitant volume (25 ± 25 vs 96 ± 29 ml), higher BNP levels were noted (385 ± 388 vs 70 ± 97 pg/ml, p 90 pg/ml, the odds ratio of an end-systolic volume index value of ≥60 ml/m 2 was 16 (95% confidence interval 5.5 to 45). In conclusion, BNP activation with MR is more pronounced in those with functional than those with organic MR, even after stratification for functional class, and independently reflects the severity of the LV alteration. Pronounced BNP activation is linked to a higher end-systolic volume index, for which it is a biomarker, irrespective of MR etiology and symptoms.