Clinical Implication of Natriuretic Peptides and Left Atrial Volume for the Screening Methods of Advanced Diastolic Dysfunction in the Community

ABSTRACT

BACKGROUND: Recently, B-natriuretic peptide (BNP) level and left atrial volume index (LAVi) were known to correlate with indices of LV diastolic function. As a screening method, we tried to evaluate the efficacy to BNP, ANP, and LAVi to predict the advanced diastolic dysfunction that means myocardial relaxation abnormality and elevated LV filling pressure. METHODS: In 100 patients who referred for echocardiography, Doppler recording of the mitral inflow and tissue Doppler imaging of the mitral annulus were obtained and classified into 4 diastolic function grades (normal, impaired relaxation, pseudonormal, and restrictive). Advanced diastolic dysfunction was defined as pseudonormal and restrictive physiology. LAVi was measured by modified Simpson's method in apical 4-chamber view at end-systole. Plasma levels of BNP and ANP were measured on the same day as echocardiogram was done. RESULTS: BNP and ANP levels were increased as diastolic function grade was worsening (BNP 60+/-92, 108+/-204, 778+/-1,023 and 1,426+/-1,421 pg/ml, p<0.001; ANP 22+/-30, 23+/-26, 94+/-92, 96+/-61 pg/ml, p<0.001). LAVi was also increased as diastolic dysfunction was advanced 24+/-7 ml/m2, 27+/-9 ml/m2, 37+/-12 ml/m2, 45+/-12 ml/m2, p<0.001. The areas under the curve of receiver-operator characteristic curve for BNP, ANP and LAVi to detect the advanced diastolic dysfunction were 0.91, 0.88 and 0.84, respectively. BNP of 137 pg/ml, ANP of 34 pg/ml, and LAVi of 30 ml/m2 were the best values of sensitivity and specificity, respectively. CONCLUSION: These data suggest that BNP, ANP and LAVi provide meaningful sensitivity and specificity for the detection of advanced diastolic dysfunction, respectively. Among these, BNP is better than ANP or LAVi for the screening method to predict the advanced diastolic dysfunction.