A Model for Predicting Persistent Elevation of Factor VIII among Patients with Acute Ischemic Stroke.

BACKGROUND AND PURPOSE: Elevated levels of coagulation factor VIII (FVIII) may persist independent of the acute-phase response; however, this relationship has not been investigated relative to acute ischemic stroke (AIS). We examined the frequency and predictors of persistently elevated FVIII in AIS patients. METHODS: AIS patients admitted between July 2008 and May 2014 with elevated baseline FVIII levels and repeat FVIII levels drawn for more than 7 days postdischarge were included. The patients were dichotomized by repeat FVIII level for univariate analysis at 150% and 200% activity thresholds. An adjusted model was developed to predict the likelihood of persistently elevated FVIII levels. RESULTS: Among 1616 AIS cases, 98 patients with elevated baseline FVIII had repeat FVIII levels. Persistent FVIII elevation was found in more than 75% of patients. At the 150% threshold, the prediction score ranged from 0 to 7 and included black race, female sex, prior stroke, hyperlipidemia, smoking, baseline FVIII > 200%, and baseline von Willebrand factor (vWF) level greater than 200%. At the 200% threshold, the prediction score ranged from 0-5 and included female sex, prior stroke, diabetes mellitus, baseline FVIII level greater 200%, and baseline vWF level greater than 200%. For each 1-point increase in score, the odds of persistent FVIII at both the 150% threshold (odds ratio [OR] = 10.4, 95% confidence interval [CI] 1.63-66.9, P = .0134) and 200% threshold (OR = 10.2, 95% CI 1.82-57.5, P = .0083) increased 10 times. CONCLUSION: Because an elevated FVIII level confers increased stroke risk, our model for anticipating a persistently elevated FVIII level may identify patients at high risk for recurrent stroke. FVIII may be a target for secondary stroke prevention.

Intravenous Tissue Plasminogen Activator for Wake-Up Stroke: A Propensity Score-Matched Analysis.

GOAL: To evaluate the safety and efficacy of intravenous (IV) tissue plasminogen activator (tPA) in the treatment of wake-up stroke (WUS) using propensity score (PS) analysis. MATERIALS AND METHODS: Consecutive acute ischemic stroke patients meeting inclusion criteria were retrospectively identified from our stroke registry between July 2008 and May 2014, and classified as stroke onset less than or equal to 4.5 hours treated with tPA (control; n = 369), tPA-treated WUS (n = 46), or nontreated WUS (n = 154). The primary outcome of interest for safety was symptomatic intracerebral hemorrhage (sICH), defined as parenchymal hemorrhage associated with a greater than or equal to 4-point increase in National Institutes of Health Stroke Scale (NIHSS) score. Multivariate logistic regression with adjustment for confounders and PS for receiving IV tPA assessed outcomes, along with PS-matched average treatment effect on the treated (ATT). FINDINGS: No significant difference was found in rates of sICH between tPA-treated WUS, nontreated WUS, and controls (2.2%, .7%, and 3%, respectively), or in the odds of sICH between tPA-treated WUS and controls (OR = .53, 95% CI = .06-4.60, P = .568). Among WUS patients, tPA treatment was significantly associated with higher odds of good functional outcome in fully adjusted analyses (OR = 7.22, 95% CI = 2.28-22.88, P = .001). The ATT of tPA for WUS patients demonstrated a significantly greater decrease in NIHSS score at discharge when compared to nontreated WUS patients (-4.32 versus -.34, P = .032). CONCLUSIONS: Comparable rates of sICH between treated WUS and stroke onset less than or equal to 4.5 hours treated with tPA suggest that tPA may be safely used to treat WUS. Superior outcomes for tPA-treated versus nontreated WUS subjects may suggest clinical efficacy of the treatment.

Factor VIII Level is Not Modifiable by Improved Glycemic Control in Patients with Ischemic Stroke.

AIMS: To determine whether the degree of glycemic control was related to change in Factor VIII (FVIII) level in patients with acute ischemic stroke (AIS). METHODS: From our stroke registry, all AIS patients admitted between 07/2008-05/2014 with baseline HbA1c and FVIII levels were eligible. Of these, patients with follow-up HbA1c and FVIII levels post-discharge were included. Elevation in FVIII was defined as level >150%. Diabetic control was categorized according to HbA1c levels:uncontrolled (>7.1%), controlled (5.7-7.0%), and normal (<5.7%) HbA1c and FVIII levels were further analyzed for evidence of a correlation as continuous variables. RESULTS: Among 1,631 AIS cases, 63 patients met inclusion criteria. Of these, 21 patients (33.3%) had uncontrolled diabetes, 27 patients (42.8%) had controlled diabetes, and 15 patients (23.4%) had normoglycemia. Baseline demographic characteristics differed only for history of hyperlipidemia (57.1% uncontrolled, 25.9% controlled, 26.7% normal, p=0.0443). Time between baseline and follow-up measures of both FVIII and HbA1c did not differ between groups (p=0.0812 and p=0.6969, respectively). There was no association between HbA1C group and FVIII level at baseline (p=0.2197) nor between change in HbA1c and change in FVIII from baseline to follow-up (r=0.0147, p=0.9092). Additionally, no statistically significant level at baseline or follow-up. CONCLUSIONS: While hyperglycemia and FVIII level are associated in the acute phase of AIS, long-term glycemic control before or subsequent to AIS was unrelated to FVIII level. Our results suggest that these stroke risk factors are independent of each other and that FVIII level cannot be modified by controlling diabetes.

Sex differences in predictors of ischemic stroke: current perspectives.

Globally, stroke is a significant public health concern affecting more than 33 million individuals. Of growing importance are the differences between males and females in the predictors and overall risk of stroke. Given that women have a higher lifetime risk for stoke and account for more than half of all stroke deaths, sex-specific stroke risk factors merit investigation and may help target public health interventions. This review aims to discuss the current body of knowledge regarding sex-specific predictors of ischemic stroke including both modifiable and non-modifiable risk factors, as well as specific pathologies known to increase stroke risk.