Abstract T MP57: Are The Recommendations For The Emergency Management Of Acute Ischemic Stroke Patients On Novel Oral Anticoagulants Sufficient?
Background: Acute ischemic stroke (AIS) patients receiving novel oral anticoagulants (NOAC) are commonly excluded from thrombolytic therapy as reliable bedside tests for anticoagulation monitoring are lacking. We aimed to prospectively investigate the applicability of our institutional protocol for the management of AIS patients on NOAC that is based on expert recommendations
Methods: We studied consecutive AIS patients not receiving NOAC and hospitalized general patients receiving NOAC. We performed standard coagulation tests including INR, activated partial thromboplastin time (aPTT), thrombin time (TT) and trough level tests for dabigatran, rivaroxaban and apixaban. In AIS patients, blood samples were taken immediately after admission.
Results: We enrolled 40 patients: mean age 73±15 yrs, 30% male, median NIHSS 3 (range 0-17), 62.5% AIS. Fifteen patients received NOAC (i.e., 5 dabigatran, 5 rivaroxaban, 5 apixaban). In AIS patients not receiving NOAC, coagulation parameters were within normal limits (INR 0.99±0.07, aPTT 27.4±2.6, TT 16.7±1.2) and significantly lower than in those on dabigatran (INR 1.28±0.15, aPTT 39.6±7.4, TT 111.9±40.8; p<0.001), rivaroxaban (INR 1.42±0.51, aPTT 32.6±4.7, TT 17±1.3; p<0.001) and apixaban (INR 1.2±0.01, p<0.001; except for aPTT 30.2±4.3, p=0.14). In patients not receiving NOAC, dabigatran was not detectable in plasma as opposed to those on dabigatran, where its concentration (79±78 ng/ml; p<0.001) was above the predefined threshold of <31 ng/ml that precludes thrombolysis. According to the predefined threshold of <4 ng/ml, rivaroxaban anti-Xa activity was elevated in 19/25 (76%) patients not receiving NOAC, but lower than in patients prescribed to rivaroxaban (8.4±4.9 vs. 54±33.6 ng/ml, p=0.0004). In patients on apixaban, anti-Xa activity (1.28±0.25 E/ml) was far above currently suggested heparin-equivalent therapeutic trough levels (i.e., 0.1-0.2 E/ml).
Conclusions: In AIS patients potentially amenable to thrombolytic therapy, altered routine coagulation tests may point to an intake of NOAC. Predefined values for dabigatran, rivaroxaban and apixaban need to be adjusted in a larger validation study and individually validated by local laboratories to be prepared for emergency situations.
Author Disclosures: J. Kepplinger: None. K. Barlinn: None. S. Gehrisch: None. J. Beyer-Westendorf: None. V. Puetz: None. U. Bodechtel: None.
- © 2014 by American Heart Association, Inc.