Abstract Number: PB0315
Meeting: ISTH 2020 Congress
Theme: Coagulation and Natural Anticoagulants » Critical Care and Perioperative
Background: Each year, millions of patients treated with direct acting oral anticoagulants (DOAC) require invasive procedures. In PAUSE, a prospective cohort study of 3,007 DOAC-treated patients undergoing elective procedures, a standardized interruption strategy was associated with a low risk of bleeding and low residual DOAC levels in many, but not all patients. DOAC-specific assays are not widely available whereas routine coagulation tests, comprising prothrombin time (PT), activated partial thromboplastin time (aPTT) and thrombin time (TT), are widely available.
Aims: To assess whether PT, aPTT and TT can identify patients with elevated residual DOAC levels after DOAC interruption for procedures.
Methods: As a pre-specified sub-analysis of PAUSE, a blood sample was obtained immediately pre-procedure. We compared PT (Siemens Thromborel), aPTT (Siemens Dade Actin FS) and TT (Sigma-Aldrich) with DOAC levels assessed by dilute thrombin time (Hemoclot, Hyphen BioMed) for dabigatran, and anti-factor Xa levels (Hyphen BioMed) for rivaroxaban and apixaban. All tests were performed on a STAr-Evolution analyzer (Diagnostica Stago) in a central lab. In the absence of a validated threshold, DOAC levels were categorized as low (< 50ng/ml) or very low (< 30ng/ml).
Results: Following standardized interruption, the majority of patients had low residual DOAC levels. Distribution of residual DOAC levels by PT (rivaroxaban, apixaban), aPTT, and TT (dabigatran) are shown in Figure 1. Most patients with normal routine coagulation assays had low or very low residual DOAC levels: 88.6% for apixaban (PT), 96.4% for rivaroxaban (PT), and 98.1 and 100% for dabigatran (aPTT and TT). However, elevated routine assays were poor predictors of high residual activity (Table 1).
Conclusions: Use of a standardized DOAC interruption strategy led to low or very low residual DOAC levels in a majority of patients. Due to low specificity, routine coagulation tests are not helpful as a rapid screening test to detect pre-procedure residual DOAC levels.
| Apixaban | Rivaroxaban | Dabigatran | Dabigatran | |||||
| Residual DOAC level (ng/mL) | PT≤15 (N=385) | PT>15 (N=86) | PT≤15 (N=194) | PT>15 (N=44) | aPTT≤35 (N=432) | aPTT>35 (N=100) | TT≤30 (N=254) | TT>30 (N=272) |
| <30 | 290 (75.32%) | 60 (69.77%) | 174 (89.69%) | 36 (81.82%) | 401 (92.82%) | 69 (69.00%) | 254 (100.00%) | 211 (77.57%) |
| 30-50 | 51 (13.25%) | 12 (13.95%) | 13 (6.70%) | 4 (9.09%) | 23 (5.32%) | 13 (13.00%) | 0 (0.00%) | 35 (12.87%) |
| >50 | 44 (11.43%) | 14 (16.28%) | 6 (3.09%) | 3 (6.82%) | 8 (1.85%) | 18 (18.00%) | 0 (0.00%) | 26 (9.56%) |
[Very low, low, and elevated DOAC levels in patients with normal vs elevated routine coagulation assay results (N, %)]
[Distribution of residual DOAC levels by PT (rivaroxaban and apixaban) and aPTT and TT (dabigatran)]
To cite this abstract in AMA style:
Vanassche T, Li N, Coppens M, Spyropoulos A, Schulman S, Syed S, Arnaoutoglou E, Douketis JD. Routine Coagulation Assays for the Detection of Residual NOAC Levels in Patients Undergoing Elective Invasive Procedures [abstract]. Res Pract Thromb Haemost. 2020; 4 (Suppl 1). https://abstracts.isth.org/abstract/routine-coagulation-assays-for-the-detection-of-residual-noac-levels-in-patients-undergoing-elective-invasive-procedures/. Accessed September 21, 2023.« Back to ISTH 2020 Congress
ISTH Congress Abstracts - https://abstracts.isth.org/abstract/routine-coagulation-assays-for-the-detection-of-residual-noac-levels-in-patients-undergoing-elective-invasive-procedures/