Diagnostic concordance between NT-proBNP and BNP for suspected heart failure.

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.

A translational approach to detecting drug-induced cardiac injury with cardiac troponins: consensus and recommendations from the Cardiac Troponins Biomarker Working Group of the Health and Environmental Sciences Institute.

Cardiac troponins (cTns) are established biomarkers of ischemic heart disease in humans. However, their value as biomarkers of cardiac injury from causes other than ischemic heart disease is now being explored, particularly in drug development. In a workshop sponsored by the Cardiac Troponin Biomarker Working Group of the Health and Environmental Sciences Institute, preclinical, clinical, and regulatory scientists discussed the application of cTns in their respective environments, issues in translating the preclinical application of cTn to clinical studies, and gaps in our understanding of cTn biology and pathobiology. Evidence indicates that cTns are sensitive and specific biomarkers of cardiac injury from varying causes in both animals and humans. Accordingly, monitoring cTns can help ensure patient safety during the clinical evaluation of new drugs. In addition, preclinical characterization of cardiac risk and cTns as biomarkers of that risk can guide relevant clinical application and interpretation. We summarize here the outcomes of the workshop which included consensus statements, recommendations for further research, and a proposal for a cross-disciplinary group of clinical, regulatory, and drug development scientists to collaborate in such research.