Christopher W Farnsworth1, Adam L Bailey1, Alan S Jaffe2, Mitchell G Scott3. 1. Department of Pathology and Immunology, Division of Laboratory and Genomic Medicine, Washington University, St. Louis, MO, United States. 2. Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN, United States. 3. Department of Pathology and Immunology, Division of Laboratory and Genomic Medicine, Washington University, St. Louis, MO, United States. Electronic address: mgscott@wustl.edu.
Abstract
OBJECTIVES: BNP and NT-proBNP are viewed as comparable in their ability to diagnose and monitor HF in clinical guidelines. However, no recent large-scale study has directly established diagnostic concordance between BNP and NT-proBNP. This study sought to assess diagnostic concordance of BNP and NT-proBNP for ruling in and ruling out heart failure (HF). METHODS: Simultaneous BNP and NT-proBNP testing was performed on 2729 patient samples with routinely ordered BNP testing. Hospital location, age, sex, creatinine, BNP and NT-proBNP were also recorded. Recommended cutoffs for BNP and NT-proBNP for ruling in and out HF were used for assessing diagnostic concordance and correlation. RESULTS: In the ED setting, concordance between BNP and NT-proBNP was 0.695 (95% CI, 0.668-0.723) by weighted kappa using the recommended cutoffs for the acute setting. In non-ED patients, the concordance was 0.642 (95% CI, 0.580-0.705) using non-acute setting cutoffs. In the ED setting, patients with eGFR <60 mL/min/1.73m2 had lower overall concordance (0.626; 95% CI 0.580-0.672) compared to those with eGFR >60 mL/min/1.73m2 (0.707, 95% CI 0.669-0.744). Patients with an eGFR <15 mL/min/1.73m2 had a much higher ratio of NT-proBNP to BNP than patients with eGFR >60 mL/min/1.73m2 (17.0 vs. 4.7, P < .001). Linear regression revealed an r2 of 0.52 in the ED setting and 0.49 in the non-ED setting between BNP and NT-proBNP. For 368 patients with multiple measurements of natriuretic peptides, 19.7% of paired temporal measurements had an increase in one peptide and a decrease in the other. CONCLUSION: The current cutoffs for diagnosing HF for NT-proBNP and BNP have relatively low diagnostic concordance and correlation, particularly among patients with chronic kidney disease.
OBJECTIVES:BNP and NT-proBNP are viewed as comparable in their ability to diagnose and monitor HF in clinical guidelines. However, no recent large-scale study has directly established diagnostic concordance between BNP and NT-proBNP. This study sought to assess diagnostic concordance of BNP and NT-proBNP for ruling in and ruling out heart failure (HF). METHODS: Simultaneous BNP and NT-proBNP testing was performed on 2729 patient samples with routinely ordered BNP testing. Hospital location, age, sex, creatinine, BNP and NT-proBNP were also recorded. Recommended cutoffs for BNP and NT-proBNP for ruling in and out HF were used for assessing diagnostic concordance and correlation. RESULTS: In the ED setting, concordance between BNP and NT-proBNP was 0.695 (95% CI, 0.668-0.723) by weighted kappa using the recommended cutoffs for the acute setting. In non-ED patients, the concordance was 0.642 (95% CI, 0.580-0.705) using non-acute setting cutoffs. In the ED setting, patients with eGFR <60 mL/min/1.73m2 had lower overall concordance (0.626; 95% CI 0.580-0.672) compared to those with eGFR >60 mL/min/1.73m2 (0.707, 95% CI 0.669-0.744). Patients with an eGFR <15 mL/min/1.73m2 had a much higher ratio of NT-proBNP to BNP than patients with eGFR >60 mL/min/1.73m2 (17.0 vs. 4.7, P < .001). Linear regression revealed an r2 of 0.52 in the ED setting and 0.49 in the non-ED setting between BNP and NT-proBNP. For 368 patients with multiple measurements of natriuretic peptides, 19.7% of paired temporal measurements had an increase in one peptide and a decrease in the other. CONCLUSION: The current cutoffs for diagnosing HF for NT-proBNP and BNP have relatively low diagnostic concordance and correlation, particularly among patients with chronic kidney disease.