Identification and guided treatment of ventricular dysfunction in general practice using blood B-type natriuretic peptide.

Abstract

B-type natriuretic peptide (BNP) is a blood test which detects ventricular wall stretch and is being increasingly used in primary care on limited evidence. To assess the practical implications and potential clinical benefit of measuring BNP to identify and guide the treatment of undiagnosed or under-treated ventricular dysfunction in at-risk patients. Screening study with single-arm intervention. A total of 1918 patients with diabetes mellitus or ischaemic heart disease aged > or =65 years registered with 12 general practices were invited; 76 patients with elevated BNP underwent BNP-guided treatment titration. Eligible patients were invited to attend for a blood test at their own practice; those with a persistently elevated plasma BNP concentration (>43.3 pmol/l) after repeat measurement were offered initiation or up-titration of treatment guided by remeasurement of BNP with a target concentration of <36 pmol/l. Seven-hundred and fifty-nine patients (40%) attended for screening; 76 (10% of 759) commenced treatment titration. Of these 76 patients, 64 (84%) were asymptomatic or had only mild breathlessness. Maximum titration effect was achieved by the second visit when 27 (36%) had achieved the BNP target concentration and the mean reduction was 10.8 pmol/l (P<0.001). The most effective therapeutic step was a switch in beta-blocker to carvedilol or bisoprolol (P<0.001). About 10% of patients with diabetes or cardiovascular disease on GP morbidity registers have a persistently raised plasma BNP concentration. Simple adjustment of their drug treatment may reduce their BNP and associated mortality risk, but further up-titration against BNP is only possible if the within-person biological variability of measurement can be reduced.