Mitral Regurgitation and Serum N-Terminal Pro-Brain Natriuretic Peptide Levels in Children: A Modification of Adult Criteria

Mitral regurgitation can result from congenital heart disease, rheumatic valve disease, or other congenital malformations of the mitral valve. Faulty valves require surgical repair or replacement. However, echocardiographic and biochemical parameters that inform surgical decision-making for adults may not be appropriate for children. To investigate whether adult parameters can be used in children, we correlated echocardiographic parameters with serum N-terminal pro-brain natriuretic peptide (NT-proBNP) levels in children with chronic mitral regurgitation. Our sample comprised 45 patients and 38 healthy children. M-mode measurements, left atrial and left ventricular volumes, and Doppler and tissue Doppler echocardiograms were collected. We graded mitral regurgitation according to European Association of Echocardiography recommendations and indexed effective regurgitant area, vena contracta, and regurgitant volume to body surface area. Patients were grouped by regurgitation severity (mild vs moderate or severe) and left ventricular end-systolic dimension (normal vs enlarged). The NT-proBNP level was higher in patients than in controls (P=0.003), higher in patients with moderate or severe regurgitation (P=0.02), and higher in patients with an enlarged left ventricle (P=0.003). Serum NT-proBNP levels correlated with effective regurgitant area (r=0.47; P=0.002), vena contracta width (r=0.46; P=0.003), regurgitant volume (r=0.32; P=0.04), left ventricular end-systolic diameter (r=0.58; P <0.001), and left atrial diameter (r=0.62; P <0.001). An NT-proBNP value of 66 pg/mL differentiated the mild regurgitation group from the moderate or severe regurgitation group. Our results correlating NT-proBNP and echocardiographic parameters indexed to body surface area indicate that these adult criteria can be used in children to grade mitral regurgitation and inform surgical decision-making.