Thrombocytopenia and In-hospital Mortality Risk among Ischemic Stroke Patients

Abstract

Thrombocytopenia has been associated with increased mortality in nonstroke conditions. Because its role in acute ischemic stroke is less well understood, we sought to determine whether thrombocytopenia at admission for acute ischemic stroke was associated with in-hospital mortality. We used data from a retrospective cohort of stroke patients (1998-2003) at 5 U.S. hospitals. Risk factors considered included conditions that can lead to thrombocytopenia (e.g., liver disease), increase bleeding risk (e.g., hemophilia), medications with antiplatelet effects (e.g., aspirin), and known predictors of mortality (e.g., National Institutes of Health Stroke Scale and Charlson Comorbidity Index scores). Logistic regression modeling evaluated the adjusted association between thrombocytopenia, defined as platelets <100,000/μL, and in-hospital mortality. Among 1233 acute ischemic stroke patients, thrombocytopenia was present in 2.3% (n = 28). A total of 6.1% (n = 75) of patients died in the hospital. In unadjusted analyses, thrombocytopenia was associated with higher mortality (8/28 [28.6%] v 67/1205 [5.6%]; P < .0001). Thrombocytopenia was also independently associated with in-hospital mortality after adjustment for National Institutes of Health Stroke Scale score and comorbidities, with an odds ratio of 6.6 (95% confidence interval 2.3-18.6). Admission thrombocytopenia among patients presenting with acute ischemic stroke predicts in-hospital mortality.