Investigating ICH severity with dabigatran and warfarin utilizing mouse models and novel imaging techniques
Won SY, Schlunk F, Dinkel J, Karatas H, Leung W, Hayakawa K, et al. Imaging of Contrast Medium Extravasation in Anticoagulation-Associated Intracerebral Hemorrhage With Dual-Energy Computed Tomography. Stroke. 2013
In their current article in Stroke, Won and colleagues have utilized a mouse model of collagenase-induced ICH to investigate ICH in the setting of dabigatran and warfarin use via 3 main aims: to establish an ICH model in which contrast extravasation (CE) can be quantified by dual energy CT (DECT); to characterize CE in ICH occurring during warfarin and dabigatran anticoagulation; and to verify PCC as a useful agent in ameliorating hematoma expansion in warfarin associated ICH. Authors found that DECT picked up on CE that hadn’t been visualized on non-con CT; that mice in the warfarin group had longer active bleeding with larger bleed sizes and worse symptomatic outcomes than those in the dabigatran or control groups; and that PCC normalized INRs and decreased bleeding size/severity in warfarin-treated groups.
Results in this study seemed to echo prior studies that showed decreased rates of ICH with patients treated with dabigatran vs warfarin. There are some limitations to translating the results of this study to human populations that need to be considered however, such as the levels of radiation/contrast utilized to measure CE, the method of ICH induction, and the recurrent question of how INR levels compare to dTT levels of warfarin and dabitatran respectively. That being said, investigating ways to better quantify active bleeding in ICH, and to have animal models in place that can be utilized in the development of potential antidotes are critical as NOAC use becomes more widespread.
Regardless of how you feel about the NOACs, the future is now, and more and more patients are showing up in the ER taking them. As data continues to accumulate, the true risks and benefits of these medications will play out. While it does, wouldn’t it be fantastic to have methods for rapid monitoring and drug reversal when needed?