Evaluation of three NT-proBNP assays for heart failure

N-terminal pro-B-type natriuretic peptide (NT-proBNP) measurement is recommended by guidelines for diagnosing and managing heart failure (HF). Accurate NT-proBNP measurement is critical for timely and effective treatment, but limited studies have compared NT-proBNP results from multiple platforms, and few studies have compared their concordance using commonly used clinical cutpoints.

The Alinity, PathFast, and Roche NT-proBNP assays were assessed in 276 patient samples, comprising 188 inpatients and 88 outpatients with normal renal function. Correlation and bias among the assays were assessed, and guideline-endorsed clinical cutpoints were used to evaluate concordance.

Passing-Bablok regression revealed a slope of 1.00 (95% CI: 0.99-1.01) for Alinity vs. Roche, 1.14 (1.11-1.16) for PathFast vs. Roche, and 1.11 (1.01-1.13) for PathFast vs. Alinity. Bland-Altman analysis revealed minimal bias among the assays, with the closest agreement observed between PathFast and Alinity (-1.85%, -43.36 to 39.65). On inpatients, the concordance was 0.97 (0.94-0.99) for Alinity vs. Roche, 0.95 (0.92-0.99) for PathFast vs. Roche, and 0.94 (0.91-0.98) for PathFast vs. Alinity. For outpatients, the concordance was 0.92 (0.84-1.00) for Alinity vs. Roche, 0.90 (0.80-1.00) for PathFast vs. Roche, and 0.97 (0.92-1.00) for PathFast vs. Alinity.

Three NT-proBNP assay platforms demonstrated high correlation, minimal bias, and high clinical concordance. The results support the clinical interchangeability of these assays at commonly used and guideline-endorsed cutpoints.