BNP thresholds should be adjusted with patient age
By Mark Pownall
Age-related cut-off points for B-type natriuretic peptide (BNP) more accurately screen for heart failure - minimising unnecessary echocardiograms – compared to a single cut-off.
An analysis of data from 5,508 patients in 10 studies suggests three age-related cut-off points all had higher sensitivity with fewer false negatives compared with a single cut-off of 400ng/l.
Most patients screened according to age were referred on for echocardiography if they needed it and very few patients with systolic dysfunction were ruled out of further investigation.
The researchers used threshold values of above 50ng/l for those under 50, 75ng/l for those aged 50-75 and 250ng/l for those over 75.
A single cut-off point for all ages has problems, as older patients tend to have significantly higher levels of BNP, the researchers point out. 2008 European Society of Cardiology guidelines recommended the 400ng/l threshold, which carries a substantial risk of missing patients with reduced left ventricular systolic function.
Study lead Professor Per Hildebrandt, head of the cardiology clinic at Frederiksberg Hospital Copenhagen, said: ‘Age-dependent decision limits will optimise the diagnostic accuracy, minimise the risk of a missed diagnosis of reduced left ventricular systolic function, and rationalise echocardiographic follow-up.'
European Heart Journal, online June 2