Analytical Evaluation of a Point-of-Care Platform for Glycated Hemoglobin and N-Terminal Pro-B-Type Natriuretic Peptide Testing in Cardiometabolic Care

Abstract

Background: Heart failure is a frequent complication of diabetes, highlighting the importance of integrated cardiometabolic assessment. Glycated hemoglobin (HbA1c) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) represent complementary biomarkers reflecting glycemic control and myocardial stress. Point-of-care testing (POCT) platforms may facilitate decentralized diagnostics and shorten analytical turnaround time. The aim of this study was to evaluate the analytical performance of the AFIAS-3 point-of-care fluorescence immunoassay platform for HbA1c and NT-proBNP measurements in comparison with established central laboratory methods.

Methods: This single-center verification study included 50 patient samples for each analyte. HbA1c measurements obtained using AFIAS-3 were compared with Tosoh G8 high-performance liquid chromatography (HPLC), while NT-proBNP measurements were compared with the cobas 8000 electrochemiluminescence immunoassay. Analytical precision and accuracy were assessed using manufacturer quality control materials. Method comparison was performed using Passing–Bablok regression, Bland–Altman analysis, and Spearman correlation. Agreement at clinical thresholds was evaluated using Cohen’s kappa statistics.

Results: For HbA1c, analytical precision was excellent, with coefficients of variation of 1.9% and 1.8%. Correlation with the reference method was strong (r = 0.98), and the mean bias was minimal (−0.03%). Agreement at the diagnostic threshold of 6.5% was excellent (κ = 0.92). For NT-proBNP, coefficients of variation were 5.3% and 15.4%. Correlation with the central laboratory method was very high (r = 0.99), although proportional bias was observed at higher concentrations (slope 1.24). Agreement at clinically relevant thresholds remained substantial.

Conclusions: The AFIAS-3 POCT platform demonstrated excellent analytical agreement for HbA1c and acceptable agreement for NT-proBNP at clinically relevant thresholds. Dual biomarker POCT may support decentralized cardiometabolic diagnostics, although NT-proBNP values at higher concentrations should be interpreted cautiously.