Stability of direct oral anticoagulants in whole blood and plasma from patients in steady state treatment

Rivaroxaban and Apixaban Anti-Xa Measurements: Impact of Plasma Storage for 7 Days at Room Temperature

“…On day 2, all measurements were within the 80 to 120% pre-defined range of acceptability. 5,6 On day 7, only two measurements were out of this range: rivaroxaban concentration of 76% of its baseline value (30, 24 and 22 ng/mL at baseline, on day 2 and day 7, respectively) and apixaban concentration of 77% of its baseline value (13, 14 and 10 ng/mL at baseline, on day 2 and day 7, respectively). These values of below 30 ng/mL were close to the limit of quantification.…”

“…In a preliminary study including 10 rivaroxaban and 10 apixaban measurements, McGrail et al reported good stability over at least 8 and 48 hours when tubes were stored at room temperature and at 5°C, respectively. 5 The major strengths of this study are its larger size (85 blood samples), the wide range of DOAC measurements, the use of two different reagent/coagulometer combinations in two distinct laboratories and its long observation timeframe (up to 7 days). Moreover, rather than a crude statistical comparison, we adopted a more clinical approach to assess the acceptability of the drift.…”

“…With a clinical-rather than statistical-point of view, we considered that the drift in rivaroxaban and apixaban concentrations was irrelevant if measurements on day 2 and day 7 fell within the pre-defined range of acceptability of 80 to 120% of the baseline value. 5,6 A Mann-Whitney test was used to compare, between-centres, the day 2 and day 7 differences from baseline and a p-value of < 0.05 was considered significant.…”

Impact of different preanalytical conditions on results of lupus anticoagulant tests

“…Several studies evaluating changes in hemostasis parameters only use acceptance criteria for bias. These studies state that the mean change should be within clinical significant limits (definitions differ from ±5% to ±20%), some including 99% CI of the mean, or define the desirable bias based on biological or analytical variation. Our study demonstrates the important fact that storage conditions may lead to increased analytical variability, and consequently, several results may exceed the allowable TE even though the bias is reasonably low (Figure D; B, B −80°C , C, C −80°C ).…”

Argatroban is stable in citrated whole blood for 24 hours

“…Although statistically significant changes observed, these were not clinically relevant as the result would not have changed the patient's treatment. A recent direct oral anticoagulant (DOAC) stability study performed by McGrail et al stated acceptable stability criterion as 80%‐120% of the baseline result, but suggest in DOAC even a 20% deviation may not be clinically relevant. McGrail et al tested the DTI dabigatran whole blood stability in patient plasma samples; however, little comparison to our results can be made due to 5 samples been analysed with baseline being 30 minutes post venepuncture at room temperature, 1 hour and 2 hours prior to centrifugation.…”