Abstract W P137: Blood Viscosity Determinants and Clinical Outcome after Ischemic Stroke
Backgrounds and Purposes: Both hematocrit (Hct) and fibrinogen (Fbg) are major blood viscosity determinants. Blood viscosity is known to be an important regulator of cerebral blood flow. However, the relationships of Hct and Fbg with clinical outcome after ischemic stroke are controversial. We aimed to elucidate association of these viscosity determinants with clinical outcome.
Methods: Consecutive patients with acute ischemic stroke admitted to our hospital within 7 days after the onset of symptoms between January 2011 and March 2013 were retrospectively studied from our single-center prospective stroke database. Plasma levels of Hct and Fbg were measured on admission. Yield shear stress (YSS) was calculated using the following equation: 13.5 (10-12) (Fbg)2 (Hct-6)3. Initial stroke severity was assessed using the National Institutes of Health Stroke Scale (NIHSS). Favorable outcome was defined as the modified Rankin Scale (mRS) 0 or 1 at 3 months.
Results: Of 1322 consecutive inpatients, 311 with premorbid mRS 2-5 and 139 with incomplete clinical data were excluded, and the remaining 872 were studied. Patients who had favorable outcome were younger (70±12 vs. 74±11, p<0.001), more commonly male (69.1 vs. 58.3 %, p=0.001), had lower NIHSS (median 2 vs. 9, p<0.001),had more hypertension (57.6 vs. 42.4 %, p=0.01) and less frequently had atrial fibrillation (21.4 vs. 37.5 %, p<0.001) than those without. Hct was 40.6±4.9 % in patients with favorable outcome and 39.2±5.4 % in those without (p<0.001). Fbg concentration was 332±74 mg/dl and 354±84 mg/dl (p<0.001), respectively, and YSS was 0.069±0.004 and 0.071±0.005 (p=0.44). Fbg (per 10 mg/dl, OR, 0.96; 95% CI, 0.94-0.98; p<0.001) and YSS (per 0.01, OR, 0.96; 95% CI, 0.92-0.99; p=0.002) remained independently significant to predict favorable outcome after adjustment for sex, age, comorbid disease and NIHSS, but Hct was not (per 1mg/dl; OR, 1.00; 95% CI, 0.97-1.04; p=0.69)
Conclusions: Lower fibrinogen and lower yield shear stress, rather than hematocrit, were independently associated with favorable outcome in acute ischemic stroke.
Author Disclosures: K. Nishimura: None. M. Koga: None. K. Nagatsuka: None. K. Minematsu: None. K. Toyoda: None.
- © 2014 by American Heart Association, Inc.