Correlation between N-terminal pro B-natriuretic peptide and ultrasonic backscatter: implications for diastolic dysfunction in hypertension.

OBJECTIVE: This study was designed to determine how N-terminal pro brain-natriuretic peptide (NT-proBNP) levels correlate with cyclic variation of integrated backscatter (CVIBS) as a reflection of abnormal diastolic function in hypertension. PATIENTS: Forty essentially hypertensive patients were studied. CVIBS values were obtained from the septal wall in the parasternal long-axis view. Twelve had normal diastolic function, 18 had impaired relaxation, and 10 had pseudonormal pattern.
RESULTS: Patients with normal diastolic function had a mean NT-proBNP concentration of 34 +/- 17 pg/ml and a mean CVIBS value of 7.1 +/- 0.9 dB; those with impaired relaxation had a mean NT-proBNP concentration of 71 +/- 25 pg/ml and a mean CVIBS value of 6.7 +/- 1.1 dB. Patients with pseudonormal pattern had the highest NT proBNP levels (206 +/- 75 pg/ml) and lowest CVIBS values (5.7 +/- 0.9 dB). An NT-proBNP value of 62 pg/ml had a sensitivity of 83% and a specificity of 91%; a CVIBS value of 7.2 dB had a sensitivity of 83.3% and a specificity of 66.7% for detecting diastolic dysfunction. An NT-proBNP value of 120 pg/ml had a sensitivity of 76% and a specificity of 96%; a CVIBS value of 6.1 dB had a sensitivity of 87.5% and a specificity of 75% for detecting severe diastolic dysfunction. A close correlation was found between the NT-proBNP and CVIBS values (r: 0.54, P < 0.05).
CONCLUSION: Combinative use of NT-proBNP and CVIBS can detect the presence of diastolic abnormalities on echocardiography. A good correlation was found between the NT-proBNP and CVIBS values in detecting diastolic dysfunction in essentially hypertensive patients.