Comparison of the Diagnostic Characteristics of Two B-Type Natriuretic Peptide Point-of-Care Devices

BackgroundB-type natriuretic peptide (BNP) is used to diagnose heart failure (HF).ObjectiveTo compare the accuracy of two commercially available point-of-care (POC) devices for measuring B-type natriuretic peptide (BNP) in emergency department (ED) patients with suspected heart failure using the central laboratory testing results as the criterion standard.MethodsVenous blood samples were collected from adults with suspected heart failure and split into three samples for BNP analysis: central laboratory (Siemens ADIVA Centaur; Siemens, Deerfield, IL), Triage BNP POC device (Biosite, San Diego, CA), and i-STAT BNP POC device (Abbott, East Windsor, NJ). The criterion standard for BNP levels was the central laboratory.ResultsTwo hundred fifty patients were enrolled. Mean (SD) age was 70.7 (13.8) years; 200 (80%) were over age 55 years; 146 (58.4%) were male. A final hospital discharge diagnosis of heart failure was made in 108 (42%) patients. The i-STAT system yielded a result within a median of 9 min (interquartile range [IQR] 9–10 min). The Triage device yielded a result within a median of 19 min (IQR 15–22 min); p < 0.001. The device failure rate for the central laboratory (8 failures, 3.2%) was significantly higher than that of the i-STAT device (1 failure, 0.4%, p = 0.04), but not statistically different than the Triage device (3 failures, 1.2%). Neither the Triage nor the i-STAT were statistically different than the central laboratory result in terms of sensitivity; the i-STAT was less specific than the Triage result (p = 0.003). The area under the curve for the Triage device was 0.95 (95% confidence interval [CI] 0.91–0.98), whereas the area under the curve for the i-STAT device was 0.98 (95% CI 0.96–0.99; p < 0.01).ConclusionsBoth POC devices tested were accurate and rarely failed; however, the i-STAT was faster with single use.