Utility of plasma n-terminal pro brain natriuretic peptide in the assessment of left ventricular systolic dysfunction

ABSTRACT

The diagnosis of heart failure [HF] is difficult, with both overdiagnosis and underdiagnosis occurring commonly in practice. Echocardiography is a standard technique in the evaluation of left ventricular function. Natriuretic peptides have been proposed as useful markers of left ventricular dysfunction. The aim of the study was to evaluate the utility of plasma amino-terminal pro-brain natriuretic peptide [NT-proBNP] for the detection of left ventricular systolic dysfunction. We measured NT-proBNP in 70 patients referred for cardiac and echocardiographic evaluation due to known symptomatic HF in 20 and high risk for HF in 50 patients. Left ventricular ejection fraction [LVEF] was determined by echocardiography and patients were categorized into 2 groups, patients with LVEF >45% and patients with LVEF<45%. There were 39 patients with LVEF >45% [31 men and 8 women with a mean age of 53 +/- 5.1 years] and 31 patients with LVEF <45% [29 men and 2 women with a mean age of 59 +/- 6.1]. There were no differences between groups regarding age or body mass index. The mean NT-proBNP concentration in patients with LVEF <45% was significantly higher than that in patients with LVEF >45% [1025 +/- 697.5 pg/ml vs. 55 +/- 30.3 pg/ml, p<0.0001]. All patients with LVEF <45% had NT-proBNP value >100 pg/ml and 36 of 39 patients with LVEF >45% had NT-proBNP value <100 pg/ml. Using this cut-off value the NT proBNP was 100% sensitive and 92% specific with negative predictive value of 92% and positive predictive value of 94% for detection of patients with LVEF <45%. Our results suggest that measurement of NT-proBNP with a commercially available diagnostic kit can be reliable for detection of left ventricular systolic dysfunction as indicated by LVEF <45%