The International Normalized Ratio calibrated for rivaroxaban has the potential to normalize prothrombin time results for rivaroxaban‐treated patients: results of an in vitro study

Tripodi, Armando; Chantarangkul, Veena; Guinet, C.; Samama, M

doi:10.1111/j.1538-7836.2010.04106.x

Cited by 112 publications

(106 citation statements)

References 7 publications

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“…This model of calibration proved feasible and effective to minimize the between-thromboplastin variability of PT-ratio induced by rivaroxaban [28]. However, the system has not yet been implemented.…”

Section: Rivaroxaban-pt-ratio ( Pt-ratio) =mentioning

confidence: 99%

“…However, the PT or APTT prolongations are heavily dependent on the reagent composition used for testing. Tripodi et al [28] have recently shown that the adoption of the INR VKA to report PT results for patients on rivaroxaban rather than minimizing, increases the between-thromboplastin variability and should therefore not be used to report PT results in these patients. Attempts have been made to devise a PT-ratio valid for rivaroxaban in which the rivaroxaban sensitivity index (called rivaroxaban-SI) is calculated by substituting in the calibration plot (working thromboplastin vs. standard thromboplastin) plasmas from patients on VKA for plasmas from patients on rivaroxaban.…”

Section: International Normalized Ratio (Inr)mentioning

confidence: 99%

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How to report results of prothrombin and activated partial thromboplastin times

Tripodi

Lippi

Plebani

2016

Clinical Chemistry and Laboratory Medicine (CCLM)

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Prothrombin time (PT) and activated partial thromboplastin time (APTT) are the most widely used tests to investigate coagulation abnormalities. Varied result reporting have been introduced over the years for the two tests, thus making their interpretation rather confusing in different clinical settings. PT results have been reported as clotting time, percentage activity, PT-ratio (patient-tonormal clotting time) and as international normalized ratio (INR). The INR scale has been devised to harmonize results stemming from different thromboplastins from patients on treatment with vitamin K antagonists. Therefore, there are some theoretical and evidence-based considerations that make the INR formally invalid when the test is used to analyze patients in other clinical settings. Unfortunately, this limitation has been frequently overlooked, and the INR has been (and is currently) used as a universal system of results harmonization. The APTT has been historically reported as clotting time or as ratio (patient-to-normal clotting time). In this opinion paper we review the current state-of-the-art for result reporting and attempt to give practical guidance on how PT and APTT should be reported in different clinical conditions for which the tests are requested.

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Section: Rivaroxaban-pt-ratio ( Pt-ratio) =mentioning

confidence: 99%

Section: International Normalized Ratio (Inr)mentioning

confidence: 99%

How to report results of prothrombin and activated partial thromboplastin times

Tripodi

Lippi

Plebani

2016

Clinical Chemistry and Laboratory Medicine (CCLM)

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“…16,19 Between-reagent variability should be considered when interpreting results. 16,19,26,30 BLOOD, 16 MAY 2013 x VOLUME 121, NUMBER 20 THE LABORATORY AND THE DIRECT ORAL ANTICOAGULANTS 4033…”

Section: Potentially Useful Othersmentioning

confidence: 99%

The laboratory and the direct oral anticoagulants

Tripodi

2013

Blood

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Although direct oral anticoagulants do not need laboratory testing for dose adjustment, there are instances when laboratory measurement of the drug anticoagulant effect may be useful. They include before initiation of treatment, before surgical or invasive procedures, on the occasion of hemorrhagic or thrombotic events, and whenever immediate reversal of anticoagulation is needed. Choice of tests should be primarily based on their prompt availability. Accordingly, the dilute-thrombin or the ecarin clotting times are best suited for dabigatran and the prothrombin time or the anti-FXa for rivaroxaban.

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“…In particular, PT results should be expressed as the clotting time ratio (patient ⁄ normal), or INR valid for this drug. Expression of the results as an INR valid for patients on VKAs is strongly discouraged as it was shown that this dramatically increases the between-reagent variability [29].…”

Section: Recommended Testsmentioning

confidence: 99%

“…Results are dependent on the type of thromboplastin used for testing, but evidence has been provided that standardization across reagents is feasible by employing an international sensitivity index (ISI) based on plasma supplemented with increasing doses of rivaroxaban [29]. This index (ISIrivaroxaban) was successfully used to convert PT ratio into INR calibrated for rivaroxaban (INR-rivaroxaban) [29], which proved effective in minimizing between-thromboplastin variability [29]. (iii) APTT.…”

Section: Rivaroxaban and Apixabanmentioning

confidence: 99%