Anticoagulant Therapy

Heparin Curve to Measure DOACs?

Does your facility measure rivaroxaban or apixaban using a chromogenic substrate anti-Xa assay based on unfractionated heparin [UFH] calibrators or UFH-low molecular weight heparin [UFH-LWMH] ‘hybrid” calibrators, or do you require rivaroxaban and apixaban calibrators? I [Geo] received a 6-22-22 response from international hemostasis expert Robert Gosselin, who cited several references. Many of us use […]

Anticoagulant Therapy

April 2022 QQ: Measuring Heparin Summary

Hello, our April 2022 Quick Question asks, “How do you measure unfractionated heparin [UFH]?” Our 37 respondents answered… Chromogenic anti-Xa using a hybrid curve: 38% [14] Chromogenic anti-Xa using the UFH curve: 14% [5] Anti-Xa and PTT: 22% [8] PTT: 26% [9] The majority of respondents are using the chromogenic anti-Xa heparin assay, and most […]

Anticoagulant Therapy

April 2022 QQ: Measuring Heparin

Our April 2022 Quick Question reprises our May 16, 2012 post, “Who Uses the Hybrid Curve?” but adds a twist based on May JE, Siniard RD, Taylor LJ, Marques MB, Gangaraju R. From activated partial thromboplastin time to anti-factor Xa and back again; the evolution of monitoring unfractionated heparin. Am J Clin Pathol 2022;157:321–7 HTTPS://DOI.ORG/10.1093/AJCP/AQAB135. […]

Anticoagulant Therapy

March 2022 Quick Question Summary

The stem of our March 2022 Quick Question was, “How do you measure the anti-Xa DOACs rivaroxaban or apixaban?” The question drew 33 responses and here are the answer selections: We don’t measure the anti-Xa DOACs: 24% [8] Chromogenic anti-Xa using DOAC-specific calibrators and controls: 64% [21] Chromogenic anti-Xa using the unfractionated heparin curve: 3% […]

Anticoagulant Therapy

March 2022 Quick Question: Measuring Anti-Xa DOACs

Please review and answer our March 2022 Quick Question, submitted by colleague and coagulation expert Dave McGlasson. Although the US FDA has never approved the chromogenic anti-Xa assay for the direct oral anticoagulants rivaroxaban and apixaban, calibrators and controls are available from several distributors. Many facilities are called upon to assay for plasma concentration in […]

Anticoagulant Therapy

Measuring DOACs

Here is a helpful article from the January 17, 2022 issue of CAP Today: “Measuring Direct Oral Anticoagulants—When, How.”

Anticoagulant Therapy

PIVKA

George is updating a book chapter and asks if there is a reason to continue using the phrase “proteins induced by vitamin K absence/antagonists” [PIVKA], now termed des-gamma-carboxy- II, VII, IX, or X. Does any laboratory continue to offer a PIVKA assay?

Anticoagulant Therapy

The Fiix-PT Assay; Improves on PT-INR?

I [Geo] received a communication from Dr. Pall Onundarson, Hematology Laboratory and Thrombosis and Hemostasis Service, Faculty of Medicine, University of Iceland, Reykjavik, Iceland, about the Fiix-PT assay designed to monitor vitamin K antagonist [warfarin, Coumadin] therapy unaffected by reductions in FVII and FIX which the authors claim to play little role in clinical anticoagulation. […]

Anticoagulant Therapy

December 2021 Quick Question: Thrombosis Risk Profile

Our December 2021 question asks, “The resident orders a thrombosis risk profile on an inpatient being treated for a pulmonary embolism [PE]. How do you respond?” This question is inspired by a case study we developed for Rutgers’ CLSC 5124 Advanced Hemostasis fall, 2021 online graduate course. Above is a screen capture that lists several […]

Anticoagulant Therapy

June, 2021 Quick Question: Dabigatran Reversal Agent

Our June, 2021 Quick Question asks, “What is the trademark name of the dabigatran reversal agent?” Here are the answers from our 25 respondents. Andexxa: 0% Bevyxxa: 8% [2] Praxbind: 88% [22] KCentra: 0% Aripazine: 4% [1] No one was stumped by this one, perhaps as we had recently posted a question about Andexxa, which […]

Anticoagulant Therapy

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George Fritsma is a medical laboratory scientist, educator, and author. George is a member of the International Society on Thrombosis and Hemostasis, the International Society for Laboratory Hematology, and the American Society for Clinical Laboratory Science.

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