Background and Purpose: White blood cell count (WBC), a marker of the atherosclerotic burden, has reportedly been a predictor of poor outcome in the general stroke population. The purpose of this study was to clarify associations between WBC on admission and outcomes among patients having acute ischemic stroke with nonvalvular atrial fibrillation (NVAF), that was principally cardioembolic.
Methods: Of those enrolled in the multicenter observational Stroke Acute Management with Urgent Risk-factor Assessment and Improvement (SAMURAI)-NVAF study, acute ischemic stroke/TIA patients (within 7 days of onset) with NVAF with premorbid modified Rankin Scale (mRS) score of 0-2 were included in the analysis. WBC on admission was categorized into quartiles. Associations between WBC count and major disability or death (mRS score of 3-6) at 90 days and 2 years were analyzed using logistic and proportional odds regression models.
Results: A total of 789 patients were studied (306 women, 76.2±9.5 years old, the median NIHSS score was 6 [IQR, 2-16], the median WBC count was 6700 [IQR, 5475-8300], the median mRS score at 90 days was 2 [IQR, 1-4], the median mRS score at 2 years was 2 [IQR, 0-5]). WBC had a significant linear association with major disability or death at 90 days (adjusted odds ratio [OR] for highest versus lowest quartile 3.53; 95% confidence interval [CI] 2.07-6.13; P for trend<0.001). Associations were similar for the outcome at 2 years (adjusted OR for highest versus lowest quartile 2.16; 95% CI 1.31-3.56; P for trend<0.001).
Conclusions: Higher WBC count on admission seems to predict a short- and long-term poor outcome in acute ischemic stroke patients with NVAF.
Clinical Trial Registration: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01581502.