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.