Abstract W P154: Von Willebrand Factor Elevation Threshold for Poor Clinical Outcomes in Patients with Ischemic Stroke
Background: Elevation in von Willebrand factor (vWF) is an independent risk factor for thromboembolic events and acute ischemic stroke (AIS). Laboratory reference ranges categorize levels >150% activity as abnormal. Our prior research demonstrated worse outcomes with severe (>200%) elevation in vWF. We sought to determine the most clinically relevant threshold value for vWF with respect to patient outcome in AIS.
Methods: From our stroke registry, patients admitted with AIS between 07/2008-10/2013 were included if vWF levels were measured during admission. Logistic regression was used to assess differences in baseline, in-hospital, and outcome variables in patients with vWF elevation as compared to those with normal levels. Optimal threshold levels were determined by assessing dichotomized vWF levels using a 5-point incremental analysis of levels with respect to outcome, and subsequent determination of the threshold yielding the largest area under the curve (AUC). The outcome was poor modified Rankin Scale (mRS) score on discharge, defined as mRS>2.
Results: Among 1,453 cases in our registry, inclusion criteria were met for 99 patients. Compared to patients with normal vWF, elevated vWF was associated with age, female gender, and diabetes. vWF elevation threshold of 200% was the best predictor of poor mRS on discharge (OR 2.88, 95% CI 1.32-6.29, p=0.0079) with an AUC of 0.629.
Conclusions: Despite a laboratory cut-off of 150% as a normal value, elevation of vWF >200% is the most clinically useful threshold for the prediction of poor clinical outcome in the setting of AIS based on data from our center.
Author Disclosures: A.A. Samai: None. A.K. Boehme: None. A. George: None. D.J. Monlezun: None. L. Dowell: None. C. Leissinger: None. L. Schluter: None. R. El Khoury: None. S. Martin-Schild: None.
- © 2015 by American Heart Association, Inc.