Abstract Details

Title Prolongation of INR after tPA in Patients Presenting as a "Stroke Code"

Topic Cerebrovascular Disease and Interventional Neurology

Presentation(s) P06 - (-)

Poster/Presentation
Number 268

Objective

Background BACKGROUND: Thrombolysis with tPA is the mainstay of therapy for acute ischemic stroke (AIS) with hemorrhagic transformation (HT) a potential complication. tPA is nonspecific for fibrin clot and may degrade coagulation factors like fibrinogen, factors V and VIII, and generate breakdown products that interfere with fibrin polymerization. These effects may prolong clotting times including INR, and may contribute to the risk for HT.

Design/Methods DESIGN/METHODS: Patients presenting either directly to our ED or as "drip-and-ship" transfers with possible AIS within 6 hours of symptom onset were prospectively enrolled and their PT measured. INR was calculated from the PT. Exclusion criteria included primary ICH, warfarin use, or other coagulopathy. Patients with diagnosis of AIS were designated cases; stroke mimics were controls. Using a 2-sided t-test, we compared the mean (+SD) INR between patients who received tPA prior to PT draw vs. those who did not.

Results RESULTS: Of 199 enrolled patients (50% female; mean age 62.1 years; median NIHSS 4, IQR 4, 8), 102 were cases and 97 were controls. Mean time from tPA infusion start to PT draw was 2.0 ± 0.8 hrs. A total of 35 (17.6%) patients received tPA, 29 of whom were cases. Of 164 (82.4%) patients who did not receive tPA, 73 were cases. Mean INRs for all patients were significantly higher in the tPA-treated group (1.15±0.16) than in the non-tPA group (1.04±0.09) (p < 0.001). INRs were also significantly higher in tPA-treated vs. not-treated cases (1.16±0.17 vs. 1.05±0.09, p<0.001) and in tPA-treated vs. non-treated controls (1.12±0.11 vs. 1.03±0.09, p=0.027).

Conclusions CONCLUSIONS: We identified a statistically significant increase in INR in patients not on warfarin treated with tPA. While the difference is small and the clinical significance is uncertain, it highlights the non-specificity of tPA, which may contribute to bleeding risk.

Authors/Disclosures
Natalie R. Weathered, MD, FAAN (University of Washington) PRESENTER	Dr. Weathered has nothing to disclose.
	No disclosure on file
Kevin Call, MD	No disclosure on file
Jana Wold, MD (University of Utah Medical Center)	Dr. Wold has nothing to disclose.
	No disclosure on file
Susan T. Herman, MD, FAAN (Barrow Neurological Institute)	The institution of Dr. Herman has received personal compensation in the range of $5,000-$9,999 for serving as a Consultant for Bioserenity. Dr. Herman has received personal compensation in the range of $500-$4,999 for serving as an officer or member of the Board of Directors for National Association of Epilepsy Centers. Dr. Herman has received personal compensation in the range of $0-$499 for serving as an Editor, Associate Editor, or Editorial Advisory Board Member for Current Treatment Options in Neurology. Dr. Herman has received personal compensation in the range of $0-$499 for serving as an Editor, Associate Editor, or Editorial Advisory Board Member for Journal of Clinical Neurophysiology. The institution of Dr. Herman has received research support from Epilepsy Foundation; Epilepsy Learning Healthcare System. The institution of Dr. Herman has received research support from CREMedical. The institution of Dr. Herman has received research support from NIH/NINDS. The institution of Dr. Herman has received research support from Marinus. The institution of Dr. Herman has received research support from Neuroelectrics, Inc. Dr. Herman has received personal compensation in the range of $500-$4,999 for serving as a Medical Director, Neurodiagnostics Program with Laboure College. Dr. Herman has a non-compensated relationship as a Professional Advisory Board member with Epilepsy Foundation that is relevant to AAN interests or activities.
	No disclosure on file
	No disclosure on file
Jennifer J. Majersik, MD, FAAN (University of Utah)	Dr. Majersik has received personal compensation in the range of $10,000-$49,999 for serving as an Editor, Associate Editor, or Editorial Advisory Board Member for Stroke. The institution of Dr. Majersik has received research support from NIH/NINDS. The institution of Dr. Majersik has received research support from NIH/NCATS.

��ɫ��

��ɫ��