Abstract TP347: The Effects of Early Anticoagulation Resumption with Apixaban on the Acute Stroke Patients
Background and Purpose: The optimal timing and safety of early anticoagulation using non-vitamin K antagonist oral anticoagulants after acute stroke or transient ischemic attack (TIA) have not been fully investigated. The aims of this study were (1) to assess the risk-benefit profile of early apixaban initiation in stroke/TIA patients and (2) to determine the association between events and plasma concentration of the early apixaban exposure.
Patients and Methods: We studied acute stroke/TIA patients with non-valvular atrial fibrillation admitted to our hospital and started apixaban from May 2013 to March 2015. The blood samples were drawn just before (0h) and 4 hours (4h) after taking apixaban median 5 (4-6) days of initiation to measure apixaban concentration (C0h, C4h) based on anti-FXa chromogenic assay.
Results: Of a total 90 patients (66 men, 79±9 y), 8 started apixaban median 3 days (IQR 2-6 days) after TIA, 69 did apixaban median 5 (3-9) days after ischemic stroke, and 13 did median 6 (3-7) days after intracerebral hemorrhage. C0h/C4h was 214±112/320±136 ng/mL in total, 170±100/239±106 ng/ml in 54 patients taking 2.5 mg apixaban BID, and 243±110/375±128 ng/mL in 36 patients taking 5 mg BID. During acute hospitalization (median 19 days), one patient experienced non-fatal gastrointestinal (GI) bleeding (C0h/C4h; 551/546 ng/mL). For median 8.4 (IQR 3.3-12.2) month-follow up in 86 patients who continued apixaban after discharge, three had clinically relevant hemorrhages: 1 subdural hematoma (C0h/C4h; 110/170 ng/mL) and 2 GI bleeding events (331/642, 395/529 ng/mL). The rate of clinically relevant hemorrhages was 6.7 %/year overall. Both C0h and C4h were higher in four patients with bleeding than the others (mean C0h 347 versus 204 ng/mL; p=0.018, C4h 472 versus 308 ng/mL; p=0.012). The receiver operating characteristic curve analysis revealed that C0h over 331 ng/mL predicted the hemorrhagic events with sensitivity 75% and specificity 89% (AUC 0.75). None developed ischemic stroke/TIA during the same period.
Conclusion: Early starting apixaban after acute stroke/TIA was safe. Bleeding events could occur in patients with trough apixaban exposure over 331 ng/mL.
Author Disclosures: T. Matsuki: None. K. Toyoda: Honoraria; Modest; Bayer Yakuhin, Ltd., Bristol Myers Squibb K.K., Nippon Boehringer Ingelheim Co.,Ltd., Phizer. A. Okamoto: None. T. Okata: None. T. Miyata: None. K. Nagatsuka: Honoraria; Modest; Bayer Yakuhin, Ltd, Boehringer Ingelheim GmbH, DAIICHI SANKYO Co., Ltd., Pfizer, Bristol-Myers Squibb. K. Minematsu: None.
- © 2016 by American Heart Association, Inc.