Abstract Number: PB1902
Meeting: ISTH 2020 Congress
Background: Patient self-testing (PST) and self-management (PSM) using point-of-care (POC) devices, have been found to improve the quality of anticoagulation, reduce thromboembolic events and all-cause mortality, and is the recommended mode of VKA monitoring by the American society of hematology. Accrued evidence supports the accuracy of LAC insensitive thromboplastins for INR testing in patients with lupus anticoagulant (LAC), however this may not be generalized for patients monitored by POC devices.
Aims: To investigate the accuracy of POC devices for measuring INR in LAC positive and negative patient cohort followed at our outpatient clinic.
Methods: We retrospectively analyzed INR results of consecutive VKA treated patients (with and without evidence of LAC) followed at our clinic and had their INR checked simultaneously by both POC device (CoaguChek® XS) and our laboratory. We used linear regression analysis to evaluate the correlation between INR results from the POC device versus laboratory INR in patients with and without evidence for LAC. We then compared the regression lines by ANCOVA.
Results: We identified 472 paired samples from 102 patients of which 44 (39.2%) were LAC positive treated with VKAs mainly for venous and arterial thrombosis with a median age of 45 years. The ANCOVA full model analysis showed a very good correlation between INR results obtained by the POC device and laboratory INR results in both LAC negative and LAC positive patients (figure). The presence of LAC had no effect in the model on the correlation between POC and lab INRs (p=0.365) while the POC INR results had a very significant effect (p=0.0001) and explained 77% of the variance in lab INR results.
Conclusions: The correlation between INR results obtained by the POC device and the laboratory was comparable for both LAC positive and negative patients, suggesting POC devices may be used for PST and PSM regardless of LAC status.
To cite this abstract in AMA style:Cohen O, Misgav M, Kenet G, Lubetsky A. Laboratory versus Point-of-Care INR Measurement in Patients with Lupus Anticoagulant – A Retrospective Cohort Analysis [abstract]. Res Pract Thromb Haemost. 2020; 4 (Suppl 1). https://abstracts.isth.org/abstract/laboratory-versus-point-of-care-inr-measurement-in-patients-with-lupus-anticoagulant-a-retrospective-cohort-analysis/. Accessed November 29, 2023.
« Back to ISTH 2020 Congress
ISTH Congress Abstracts - https://abstracts.isth.org/abstract/laboratory-versus-point-of-care-inr-measurement-in-patients-with-lupus-anticoagulant-a-retrospective-cohort-analysis/