Plasma amino-terminal pro-brain natriuretic peptide and accuracy of heart-failure diagnosis in primary care: a randomized, controlled trial.

OBJECTIVES The purpose of this study was to determine the effect of amino-terminal pro-brain natriuretic peptide (N-BNP) on the diagnostic accuracy of heart failure (HF) in primary care. BACKGROUND The accurate diagnosis of patients with suspected HF presenting in primary care is difficult. Amino-terminal pro-brain natriuretic peptide is present in high levels in cardiac dysfunction and may improve the diagnostic accuracy of HF in primary care. METHODS The Natriuretic Peptides in the Community Study was a prospective, randomized controlled trial of the effect of N-BNP on the accuracy of HF diagnosis. Patients presenting to their general practitioner (GP) with symptoms of dyspnea and/or peripheral edema were included. The GPs formulated an initial diagnosis based on clinical assessment. All patients underwent a full cardiologic assessment that included echocardiography and N-BNP. Each patient was randomized to the BNP group (GP received the N-BNP result) or the control group (GP did not receive the N-BNP result). Patients were then reviewed by their GP, and their diagnosis was reviewed. The primary end point was the accuracy of the GPs' diagnoses compared with the panel standard. RESULTS A total of 305 patients were included; mean age was 72 years, 65% were female. Seventy-seven patients met the panel criteria for HF. The diagnostic accuracy improved 21% in the BNP group and 8% in the control group (p = 0.002). The main impact of N-BNP measurement on diagnostic accuracy was the GPs' correctly ruling out HF. The number needed to diagnose by N-BNP measurement was seven patients. CONCLUSION This study demonstrates that N-BNP measurement significantly improves the diagnostic accuracy of HF by GPs over and above customary clinical review.