Prognostic threshold levels of NT-proBNP testing in primary care

Chronic heart failure (HF) is a common condition with a poor prognosis. As delayed diagnosis and treatment of HF patients in primary care can be detrimental, risk-stratified waiting lists for echocardiography might optimize resource utilization. We investigated whether a prognostic threshold level of the cardiac peptide, NT-proBNP, could be identified. From 2003-2005, 5875 primary care patients with suspected HF (median age 73 years) had NT-proBNP analysed in the Copenhagen area. Eighteen percent died and 20% had a cardiovascular (CV) hospitalization (median follow-up time: 1127 and 1038 days, respectively). In Cox proportional hazards regression models regarding NT-proBNP levels, the fourth decile (range: 83-118 pg/mL) was associated with a 90% (95% CI: 30-190, P < 0.01) increased risk for CV hospitalization and the seventh decile (range: 229-363 pg/mL) was associated with an 80% (95% CI: 20-190, P = 0.01) increased mortality risk after adjustment for age, sex, previous hospitalization, CV diseases, and chronic diseases. We identified prognostic threshold levels for mortality and CV hospitalization for NT-proBNP in primary care patients suspected of HF. Our results have the potential to be used to risk-stratify waiting lists for echocardiography.