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Evaluation of a new PT‐INR monitoring system in patients with the antiphospholipid syndrome
Author(s) -
Braham S.,
Novembrino C.,
Moia M.,
Torresani E.,
Tripodi A.
Publication year - 2016
Publication title -
international journal of laboratory hematology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.705
H-Index - 55
eISSN - 1751-553X
pISSN - 1751-5521
DOI - 10.1111/ijlh.12523
Subject(s) - medicine , antiphospholipid syndrome , point of care , bland–altman plot , point of care testing , vitamin k , gastroenterology , limits of agreement , thrombosis , nuclear medicine , immunology , pathology
Summary Introduction Patients on anticoagulant therapy with vitamin K antagonists (VKA) need frequent INR monitoring. Reliability of point‐of‐care (POC) devices for measuring INR needs rigorous evaluation, particularly in patient with the antiphospholipid syndrome (APS). The aim of this study was to evaluate the accuracy of the ProTime InRhythm ™ System (here called device) for INR measurement in patients with APS on VKA. Methods We compared the device INR vs . the laboratory INR measurement for blood samples from 29 APS‐positive and 31 APS‐negative patients consecutively enrolled. APS was confirmed by positive serological and/or phospholipid‐dependent coagulation tests. Chromogenic factor X assay was used to evaluate anticoagulation. Bland–Altman difference plot for paired INR (POC vs . laboratory) was used to evaluate agreement between the device and the laboratory. The device INR relationship with factor X chromogenic assay was evaluated by orthogonal regression analysis. Results Overall, 97% of the device INR measurements were similar to laboratory INR values with an absolute difference less than 0.4 units. Correlation coefficient for the device INR vs . factor X was −0.69 ( P < 0.0001, CI 95% −0.80 to −0.52). Conclusions The ProTime InRhythm System ™ is an accurate point‐of‐care device for measuring INR also in patients with and without APS.