N-Terminal Pro-B Type Natriuretic Peptide Imply Left Ventricular Diastolic Function but Is a Low Sensitivity Marker

Background: Correlations between NT-proBNP with diastolic echocardiographic parameters were not analyzed precisely. We sought to evaluate the clinical implication of NT-proBNP on the LV diastolic function in large scale databases. Methods: NT-proBNP (n = 23,029) and echocardiography databases (n = 48,750) were collected. Cases measured within 24 hours were enrolled and increased serum creatinine level (>2.0 pg/mL) or acute coronary syndrome were excluded. Finally, echocardiographic parameters were compared with serum NT-proBNP levels in 1852 patients. Results: Among patients (54% female, mean age 63.0 ± 0.3), 460 patients (24.8%) showed preserved LV systolic functions (LVEF ≥ 40%, 53.5 ± 0.4%). NT-proBNP levels were significantly correlated with LVEF (r = −0.52, P = .01), LA volume index (r = 0.50, P = .01), E/E′ (r = 0.44, P = .01), RV systolic pressure (r = 0.43, P = .01) and LV mass index (r = 0.40, P = .01). NT-proBNP showed low sensitivities to determine E/E′ ratio above 15 and LAVI above 27 on cut-off values of the ROC curve with specificity of 80% (51.7% at 686.6 ng/L, 58.7% at 643.1 ng/L). Interestingly, in patients with preserved systolic function (55.9% male, mean age 61.2 ± 0.7), NT-proBNP showed slightly high sensitivity than in total study group (53.5% at 717.0 ng/L, 60.9% at 443.3 ng/L). Conclusions: Although NT-proBNP was proved as a useful parameter for assessing LV diastolic function as well as systolic function, it showed relatively low sensitivity to determining LV diastolic function. Therefore, NT-proBNP may imply LV diastolic function but should be interpreted with combining clinical informations.