Identification and guided treatment of ventricular dysfunction in general practice using blood B-type natriuretic peptide
Mant D., Hobbs R., Glasziou P., Wright L., Hare R., Perera R., Price C., Cowie M.
Background: 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. Aim: 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. Design of study: Screening study with single-arm intervention. Setting: A total of 1918 patients with diabetes mellitus or ischaemic heart disease aged ≥65 years registered with 12 general practices were invited; 76 patients with elevated BNP underwent BNP-guided treatment titration. Method: 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. Results: Seven-hundred and fifty-nine patients (40%) attended for screening; 76 (10% of 759) commenced treatment tiltration. 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 carvedliol or bisoprotol (P < 0.001). Conclusion: 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. © British Journal of Geneneral Practice.