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.