Cost-Effectiveness of BNP Measurement in Acute Dyspnea
Abstract & Commentary
By David J. Pierson, MD, Editor, Professor, Pulmonary and Critical Care Medicine, Harborview Medical Center, University of Washington, Seattle, is Editor for Critical Care Alert.
Synopsis: This study in patients presenting to the emergency department with acute dyspnea showed that rapid BNP testing is cost-effective during the initial hospital encounter as well as at 180 days.
Source: Mueller C, et al. Arch Intern Med. 2006;166:1081-1087.
Mueller and colleagues at the University Hospital in Basel, Switzerland, investigated the clinical utility and cost-effectiveness of immediately measuring the serum level of B-type natriuretic peptide (BNP) in patients presenting to the emergency department with acute dyspnea. The clinical results of the BNP Acute Shortness of Breath Evaluation (BASEL) study, a randomized single-blind clinical trial of 452 patients, were published in 2004.1 This paper presents a prospectively identified cost-effectiveness analysis from that study.
Patients presenting with acute dyspnea who did not have trauma, severe renal disease, or cardiogenic shock, were randomized to have immediate measurement of BNP using a point-of-care assay or to receive conventional assessment and management without BNP measurement. The patients were generally elderly (mean age, 71 years). About half of them had known coronary artery disease, and slightly fewer had known obstructive lung disease. Heart failure was considered unlikely if the BNP level was < 100 pg/mL (36% of patients), most likely if the level was > 500 pg/mL (36%), and uncertain if the level was between 100 and 500 pg/mL (28%).
Patients in the BNP group had appropriate therapy initiated more rapidly (median time, 63 vs 90 min; P = 0.03) and were less likely to be admitted to the hospital (75% vs 85%; P = 0.008), than patients in the conventional care group. In addition, patients in the BNP group were less likely to be admitted to the ICU (15% vs 24%; P = 0.01). BNP-assigned patients had shorter hospital lengths of stay, both initially (median, 8 vs 10 days; P = 0.02) and during the 180-day observation period (10 vs 14 days; P = 0.005). The diagnosis of COPD exacerbation was made more often in the BNP group than in the control group (23% vs 11%, respectively; P = 0.001). Total initial treatment costs were less in the BNP group ($5410 vs $7264; P = 0.006), as were total treatment costs at 180 days ($7930 vs $10,503; P = 0.004). All-cause mortality initially and at 180 days (about 20%) was not different in the 2 groups.
BNP testing has become widespread in the assessment of patients with dyspnea, as well as in suspected heart failure and for following the course of patients with known heart failure. Its utility seems to be greatest when there is diagnostic uncertainty—when the patient does not have clear features of heart failure or another, non-cardiac cause for acute dyspnea.
Although the BASEL study looked only at patients presenting to the emergency department, it is tempting to assume that BNP testing would also be both clinically useful and cost-effective in evaluating hospitalized patients who develop acute dyspnea (although this has not been studied). In an editorial on BNP and cost-effectiveness analysis accompanying the paper by Mueller et al, Hlatky and Heidenreich2 conclude by stating, "In patients with neither clear evidence of heart failure nor an extremely low suspicion of heart failure, it is reasonable to expect that BNP testing will lead to a definitive diagnosis more rapidly and will pay for itself with more efficient clinical management." Based on the findings of Mueller et al in the BASEL study, I agree.
- Mueller C, et al. N Engl J Med. 2004;350:647-654.
- Hlatky M, Heidenreich P. Arch Intern Med. 2006;166:1063-1064.