NT-proBNP to exclude heart failure in primary care - a pragmatic, cluster-randomized study

Heart failure (HF) is difficult to recognize in primary care. N-terminal pro B-type natriuretic peptide (NT-proBNP) can be used as a rule-out test in HF due to its high negative predictive value. We aim to determine whether the number per 1000 patients of HF diagnoses increase among patients referred from primary care to an outpatient HF clinic, if general practitioners (GPs) were offered NT-proBNP in a real-life setting. All GP practices covered by Randers Regional Hospital were randomized to an intervention group (34 GP practices) and a control group (35 GP practices) in this pragmatic, cluster-randomized controlled trial. The main outcome was the number of patients referred to echocardiography and diagnosed with HF in each group. The number of patients per 1000 diagnosed with HF in the two groups was the same (0.09 (0.02-0.16) vs. 0.14 (0.07-0.21), p = .3541). A total of 700 NT-proBNP analyses, of which 611 were unique, were requested from 31 GP practices in 17.5 months. A total of 184 patients were referred to echocardiography on suspicion of HF. The number of patients per 1000 referred in the intervention group was significantly higher (p < .010). NT-proBNP was measured in 36.6% of referred patients in the intervention group. Significantly more women were diagnosed with HF in the intervention group (56.3% vs. 0%, p = .019). Hence, increased diagnostic effectiveness could not be shown in this real-life setting.