Abstract Number: PB0058
Meeting: ISTH 2021 Congress
Theme: Coagulation and Natural Anticoagulants » Coagulation Factors and Inhibitors
Background: Direct oral anticoagulants (DOAC) including the anti-Xa inhibitors apixaban, edoxaban and rivaroxaban are effective and safe for the treatment of venous thromboembolism (VTE) also in cancer patients. DOAC are absorbed predominantly in the upper gastrointestinal tract, which raises concern in cancer patients after gastrectomy regarding achievement of adequate DOAC plasma levels.
Aims: We aimed to evaluate the absorption of oral anti-Xa inhibitors in cancer patients after gastrectomy.
Methods: Using chromogenic anti-Xa assays calibrated for apixaban, edoxaban or rivaroxaban (STA Liquid Anti-Xa, Diagnostica Stago), we measured anti-Xa levels in plasma of eight cancer patients after partial or total gastrectomy who required oral anticoagulation because of VTE or atrial fibrillation. Levels were determined immediately before (trough) and 2-3 hours after drug intake (peak). Rivaroxaban was administered with food.
Results: Patient characteristics including anti-Xa levels and coagulation parameters of eight patient with upper gastrointestinal cancer who underwent total or partial gastrectomy before and after administration of an anti-Xa inhibitor are shown in Table 1 and Table 2. All patients had anti-Xa levels well above the detection limit 2-3 hours after drug intake. In two patients edoxaban trough levels were below the detection limit. One Patient was switched to rivaroxaban with trough levels slightly above the detection limit. One patient discontinued edoxaban and refused further anticoagulation. None of the patients had a thromboembolic event during treatment with DOAC, one patient had major bleeding after brachial artery puncture.
Table 1: Patient characteristics and medical history.
| Patient number | Sex | Age | Weight in kg | Surgery | Indication | Duration of anticoagulation in months* | |
| 1 | w | 55 | 70 | total gastrectomy | PE | 8 | |
| 2 | w | 37 | 43 | total gastrectomy | PE, DVT | 8 | |
| 3 | m | 76 | 65 | partial gastrectomy | DVT | 50 | |
| 4 | m | 57 | 65 | total gastrectomy | Splenic vein thrombosis | 26 | |
| 5 | m | 76 | 84 | partial gastrectomy | PE | 11 | |
| 6 | m | 76 | 92 | total gastrectomy | DVT, PE | 4 | |
| 7 | m | 80 | 88 | total gastrectomy | A-fib | 14 | |
| 8 | w | 81 | 39 | total gastrectomy | A-fib | 0,1 | |
Table 1: Patient characteristics and medical history. Abbreviations: PE – pulmonary embolism, DVT – deep vein thrombosis , A-fib – atrial fibrillation; * time from first intake of DOAC until end of observation period
Table 2: Trough and peak anti-Xa levels and coagulation parameters.
| trough level | peak level | ||||||||
| Patient number | DOAC | Dosage | Creatinine Clearance (ml/min) | anti-Xa (ng/ml) |
PT (%) |
aPTT (s) |
anti-Xa (ng/ml) |
PT (%) |
aPTT (s) |
| 1 | Rivaroxaban | 1x20mg | 56,8 | 45 | 100 | 34,1 | 210 | 85 | 44,3 |
| 2 | Edoxaban | 1x30mg | 67,9 | <20 | 71 | 28,8 | 83 | 60 | 33,6 |
| 2 | Rivaroxaban | 1x20mg | 75,8 | 22 | 65 | 29,9 | 39 | 65 | 31,2 |
| 3 | Apixaban | 2×2,5mg | 57,8 | 26 | 87 | 35,0 | 65 | 78 | 38,0 |
| 4 | Rivaroxaban | 1x20mg | 93,7 | 27 | 93 | 30,4 | 437 | 72 | 39,4 |
| 5 | Rivaroxaban | 1x20mg | 67,9 | 65 | 58 | 34,5 | 257 | 47 | 43,0 |
| 6 | Rivaroxaban | 1x20mg | 54,5 | 40 | 80 | 32,8 | 228 | 67 | 40,8 |
| 7 | Edoxaban | 1x60mg | n.a. | 51 | 73 | 39,5 | 195 | 66 | 47,7 |
| 8 | Edoxaban | 1x30mg | 39,9 | <20 | 62 | 40,4 | 171 | 56 | 49,9 |
Table 2: Trough and peak anti-Xa levels and coagulation parameters. Abbreviations: DOAC – direct oral anticoagulant, PT – prothrombin time, aPTT – activated partial thromboplastin time, n.a. – not available; Creatinine clearance estimated with the Cockcroft-Gault equation
Conclusions: Direct oral anti-Xa inhibitors are well absorbed in cancer patients after partial or total gastrectomy, but trough and peak levels vary considerably. Studies investigating clinical endpoints are warranted.
To cite this abstract in AMA style:
Puhr HC, Ilhan-Mutlu A, Quehenberger P, Kyrle PA, Eichinger S, Eischer L. Are Direct Oral Anti-Xa Inhibitors Absorbed in Cancer Patients after Gastrectomy? A Case Series [abstract]. Res Pract Thromb Haemost. 2021; 5 (Suppl 2). https://abstracts.isth.org/abstract/are-direct-oral-anti-xa-inhibitors-absorbed-in-cancer-patients-after-gastrectomy-a-case-series/. Accessed May 16, 2022.« Back to ISTH 2021 Congress
ISTH Congress Abstracts - https://abstracts.isth.org/abstract/are-direct-oral-anti-xa-inhibitors-absorbed-in-cancer-patients-after-gastrectomy-a-case-series/