BIOCHEMICAL DETECTION OF LEFT-VENTRICULAR SYSTOLIC DYSFUNCTION

Background In previous studies on the use of natriuretic peptides to d etect left-ventricular systolic dysfunction, a higher rate of cardiac disorders in the control groups than in the study groups could have le d to bias. We investigated the effectiveness of plasma N-terminal atri al natriuretic peptide (NT-ANP) and brain natriuretic peptide (BNP) co ncentrations to show left-ventricular systolic dysfunction in a random sample of the general population. Methods We randomly selected 2000 p articipants aged 25-74 years from family physicians' lists in Glasgow, UK. We sent all participants questionnaires, 1653 respondents underwe nt echocardiography and electrocardiography. We took a left-ventricula r ejection fraction of 30% or less to show left-ventricular systolic d ysfunction. NT-ANP and BNP were measured in plasma by RIAs. Findings 1 252 participants had analysable electrocardiograms and echocardiograms , completed available blood samples. Median and BNP were significantly higher in participants with left-ventricular systolic dysfunction (2. 8 ng/mL [IQR 1.8-4.6] and 24.0 pg/mL [18.0-33.0]) than in those withou t (1.3 ng/mL [0.9-1.8] and 7.7 pg/mL [3.4-13.0]; each p<0.001). Among participants with left-ventricular systolic dysfunction, both symptoma tic and asymptomatic subgroups had raised NT-ANP and BNP concentration s, A BNP concentration of 17.9 pg/mL or more gave a sensitivity of 77% and specificity of 87% in all participants, and 92% and 72% in partic ipants aged 55 years or older, NT-ANP Interpretation Measurement of BN P could be a cost-effective method of screening for left-ventricular s ystolic dysfunction in the general population, especially if its use w ere targeted to individuals at high risk.