Biochemical diagnosis of ventricular dysfunction in elderly patients in general practice: observational study.

OBJECTIVE To investigate the usefulness of measuring plasma concentrations of B type natriuretic peptide in the diagnosis of left ventricular systolic dysfunction in an unselected group of elderly people. DESIGN Observational study. SETTING General practice with four centres in Poole, Dorset. PARTICIPANTS 155 elderly patients aged 70 to 84 years. MAIN OUTCOME MEASURES Diagnostic characteristics of plasma B type natriuretic peptide measured by radioimmunoassay as a test for left ventricular systolic dysfunction assessed by echocardiography. RESULTS The median plasma concentration of B type natriuretic peptide was 39.3 pmol/l in patients with left ventricular systolic dysfunction and 15.8 pmol/l in those with normal function. The proportional area under the receiver operator curve was 0.85. At a cut-off point of 18.7 pmol/l the test sensitivity was 92% and the predictive value 18%. CONCLUSIONS Plasma concentration of B type natriuretic peptide could be used effectively as an initial test in a community screening programme and, possibly, using a low cut-off point, as a means of ruling out left ventricular systolic dysfunction. It is, however, not a good test to "rule in" the diagnosis, and access to echocardiography remains essential for general practitioners to diagnose heart failure early.