Medical and Economic Long-Term Effects of B-Type Natriuretic Peptide Testing in Patients with Acute Dyspnea Tobias Breidthardt, 1 Kirsten Laule, 1 Anne-Henny Strohmeyer, 1 Christian Schindler, 2 Sophie Meier, 1 Michael Fischer, 1 Andre ´ Scholer, 3 Markus Noveanu, 1 Michael Christ, 1 Andre ´ P. Perruchoud, 1 and Christian Mueller 1* Background: The objective of this prospective study was to assess the medical and economic long-term effects of using B-type natriuretic peptide (BNP) con- centrations in the management of patients with acute dyspnea. Methods: We performed follow-up analysis of the B- Type Natriuretic Peptide for Acute Shortness of Breath Evaluation, a randomized study including 452 patients who presented to the emergency department with acute dyspnea. Participants were randomly assigned to a di- agnostic strategy involving the rapid measurement of BNP concentrations (n  225) or standard assessment (n  227). Mortality was assessed at 720 days, morbidity and economic data at 360 days. Results: BNP testing induced several important changes in initial patient management, including a reduction in the initial hospital admission rate, the use of intensive care, and initial time to discharge. At 720 days, 172 deaths had occurred. Cumulative all-cause 720-day mor- tality was not different between the BNP group (37%) and the control group (36%, P  0.6). Morbidity as reflected by days spent in-hospital at 360 days was significantly lower in the BNP group [median 12 days ([interquartile range 2–28 days)] compared with the control group [median 16 (7–32)] days, P  0.025]. Functional status was similar in both groups. Economic outcome as quantified by total treatment cost at 360 days was significantly improved in the BNP group (mean $10 144 vs $12 748 in the control group, P  0.008). Conclusions: Rapid BNP testing in patients with acute dyspnea has no effect on long-term mortality. However, morbidity as quantified by days spent in-hospital and economic outcome are still improved at 360 days. © 2007 American Association for Clinical Chemistry The evaluation and management of patients presenting to the emergency department (ED) 4 with acute dyspnea is challenging. Among more than 30 diagnoses that may be responsible for acute dyspnea, heart failure (HF) is very common and clinically important (1–3 ). Unfortunately, the rapid and accurate differentiation of HF from other causes of acute dyspnea often remains elusive. Misdiag- nosis of HF can lead to morbidity, mortality, and in- creased resource utilization. The cost of HF is estimated to be $100 billion a year in Europe and the US, 70% of which is due to hospitalization (1–3 ). Therefore, accurate and cost-effective diagnosis and management of HF is of paramount importance. B-type natriuretic peptide (BNP) seems to be extremely helpful in this setting. BNP concentrations are quantita- tive markers of HF—the more severe the disease, the higher the BNP concentration (4, 5). The use of BNP concentrations in addition to clinical judgment signifi- cantly increases the accuracy of the clinical evaluation (6–9). The randomized B-Type Natriuretic Peptide for Acute Shortness of Breath Evaluation (BASEL) study showed that the use of BNP concentrations improved initial patient management and was cost-effective at 6 months (10, 11). It is currently unknown whether the use 1 Department of Internal Medicine, University Hospital, Basel, Switzer- land. 2 Institute for Social and Preventive Medicine, Basel, Switzerland. 3 Department of Laboratory Medicine, University Hospital, Basel, Switzer- land. * Address correspondence to this author at: Department of Internal Med- icine, University Hospital, Petersgraben 4, CH 4031 Basel, Switzerland. Fax 0041-61-2655353; e-mail chmueller@uhbs.ch. Received November 6, 2006; accepted May 31, 2007. Previously published online at DOI: 10.1373/clinchem.2006.081448 4 Nonstandard abbreviations: ED, emergency department; HF, heart fail- ure; BNP, B-type natriuretic peptide; BASEL, B-Type Natriuretic Peptide for Acute Shortness of Breath Evaluation; NYHA, New York Heart Association. Clinical Chemistry 53:8 000 – 000 (2007) Evidence-Based Laboratory Medicine and Test Utilization 1 http://www.clinchem.org/cgi/doi/10.1373/clinchem.2006.081448 The latest version is at Papers in Press. Published June 22, 2007 as doi:10.1373/clinchem.2006.081448 Copyright (C) 2007 by The American Association for Clinical Chemistry