Bluetooth enabled point-of-care INR device validation for warfarin management

Systems employing point-of-care (POC) INR monitoring with patient self-testing require test accuracy, data integrity, patient compliance, and prompt two-way communication for high quality warfarin management. With a goal of validating a POC Bluetooth capable device for prompt INR transfer to electronic medical record, two POC INR devices were compared against an internal plasma INR reference.

A multicenter study (February 14, 2023 - August 29, 2023) comparing concordance of two commercially available POC devices, Vantus and CoaguChek XS (Pro and Plus), against a plasma INR reference, was pursued among warfarin treated patients. Appropriateness of dosing decisions were assessed for each device.

Across three Mayo Clinic sites, 151 warfarin treated patients agreed to participate. Atrial fibrillation (41.7 %), venous thromboembolism (33.1 %) and heart valve prosthesis (19.9 %) were common indications with target INR range 2.0-3.0 in 89 %. For the CoaguChek devices, 86.1 % of values fell within 0.4 INR units compared with plasma INR referent (CoaguChek - plasma INR correlation R² = 0.95). For the Vantus device, 88.7 % of values fell within 0.4 INR units of plasma INR values (Vantus - plasma INR correlation R² = 0.96). Mean (± standard deviation) deviation from plasma INR was 0.2 ± 0.3 for CoaguChek compared to 0.1 ± 0.2 for Vantus (p < 0.001). Using the plasma INR as the gold standard for dosing recommendations, appropriate dosing recommendations were similar between devices: CoaguChek 83.4 % vs Vantus 82.7 %.

Compared to a plasma referent, INR values obtained from the CoaguChek and Vantus devices exhibited strong correlation with plasma INR values without systemic bias.