B-Type Natriuretic Peptide Testing, Clinical Outcomes, and Health Services Use in Emergency Department Patients With Dyspnea A Randomized Trial

Background: B-type natriuretic peptide (BNP) is used to diagnose heart failure, but the effects of using the test on all dyspneic patients is uncertain. Objective: To assess whether BNP testing alters clinical outcomes and health services use of acutely dyspneic patients. Design: Randomized, single-blind study. Patients were assigned to a treatment group through randomized numbers in a sealed envelope. Patients were blinded to the intervention, but clinicians and those who assessed trial outcomes were not. Setting: 2 Australian teaching hospital emergency departments. Patients: 612 consecutive patients who presented with acute severe dyspnea from August 2005 to March 2007. Intervention: BNP testing (n = 306) or no testing (n = 306). Measurements: Admission rates, length of stay, and emergency department medications (primary outcomes); mortality and readmission rates (secondary outcomes). Results: There were no between-group differences in hospital admission rates (85.6% [BNP group] vs. 86.6% [control group]; difference,-1.0 percentage point [95% CI,-6.5 to 4.5 percentage points]; P = 0.73), length of admission (median, 4.4 days [interquartile range, 2 to 9 days] vs. 5.0 days [interquartile range, 2 to 9 days]; P = 0.94), or management of patients in the emergency department. Test discrimination was good (area under the receiveroperating characteristic curve, 0.87 [CI, 0.83 to 0.91]). Adverse events were not measured. Limitation: Most patients were very short of breath and required hospitalization; the findings might not apply for evaluating patients with milder degrees of breathlessness. Conclusion: Measurement of BNP in all emergency department patients with severe shortness of breath had no apparent effects on clinical outcomes or use of health services. The findings do not support routine use of BNP testing in all severely dyspneic patients in the emergency department.