Abstract 3251: Relationship Between tPA and Factor VIII Levels in Patients with Acute Ischemic Stroke
Background: Factor VIII levels may be screened as part of a hypercoagulable work-up in patients with ischemic stroke. However, it is unknown how treatment with IV tPA may affect these levels during the acute phase of ischemic stroke.
Methods: From our prospective registry, we identified patients who presented with acute ischemic stroke to our stroke center between July 2008 and April 2011 and determined if factor VIII levels had been measured during the acute hospitalization. We compared mean factor VIII levels using independent sample t test in patients not treated with IV tPA to post-tPA treatment levels using independent samples t tests.
Results: Of the 72 patients who had factor VIII levels checked during admission, 25 (34.7%) received IV tPA. The mean factor VIII level was observed to be lower in patients who were treated with tPA (140.8 vs 180.5, p=0.048). Patients who experienced averted stroke (36%, 9/25) had significantly lower mean factor VIII level than patients who completed infarction on diffusion-weighted MRI (64%, 16/25) (132.7 vs 175.2, p=0.002). Of patients with post-tPA factor VIII levels, the mean factor VIII level of those whose samples were drawn within 24 hours of tPA were not different than the mean factor VIII level of those whose samples were drawn more than 24 hours after tPA (p=0.784).
Conclusion: Our observations found that factor VIII levels were lower in both patients treated with IV tPA and in patients with averted stroke. As factor VIII levels were drawn after thrombolytic therapy was administered, this raises the question of whether tPA lowers factor VIII levels or if factor VIII can serve as a potential surrogate marker for recanalization. Prospective studies examining factor VIII levels (1) before and after treatment with IV tPA and (2) in comparison to recanalization are needed to clarify this interesting observation.
- © 2012 by American Heart Association, Inc.