OBJECTIVETo explore the clinical value of plasma N-terminal pro-brain natriuretic peptide (NT-proBNP) detection in the diagnosis of diastolic heart dysfunction.

METHODSNinety patients with diastolic heart dysfunction and left ventricular ejection fraction (LVEF)>or=45% were divided into 3 groups according to the findings by conventional echocardiography and/or tissue Doppler imaging, namely impaired relaxation pattern group (n=58), pseudonormal pattern group (n=22) and restrictive filling pattern group (n=10). Ten patients with normal heart function served as the control group. Plasma NT-proBNP level was determined in all the subjects and its correlation to diastolic heart dysfunction was analyzed.

RESULTSCompared with the control group, all the 3 case groups had significantly higher plasma NT-proBNP level (P<0.01). Plasma NT-proBNP level increased gradually with the severity of diastolic dysfunction. Spearman rank correlation analysis indicated that lg(NT-proBNP) was positively correlated to the severity of diastolic dysfunction. Simple linear regression showed that 52.7% of the total variation of lg(NT-proBNP) was correlated to the severity of the condition. The ROC curve demonstrated a sensitivity of 80%, specificity of 90%, positive predictive value of 84.2% and the negative predictive value of 87.1% for NT-proBNP level of 133 ng/L in predicting diastolic heart dysfunction regardless of the clinical manifestations, and the sensitivity was 81.7% and specificity was 75% for NT-proBNP level at 280.25 ng/L in predicting symptomatic diastolic heart dysfunction; the sensitivity was 81.2% and the specificity was 92.6% for NT-proBNP at 655 ng/L in predicting moderate to severe diastolic heart dysfunction.

CONCLUSIONPlasma NT-proBNP level increases gradually with the severity of diastolic dysfunction and has a high clinical value in severity rating and assisting the diagnosis of diastolic dysfunction.