Abstract 3305: Intensive Lipid-lowering and Early Functional Outcome in Acute Ischemic Stroke: Propensity Score Matching Analysis

Abstract

Background This retrospective case-control study was designed to compare the effect of early high-dose atorvastatin treatment on early functional outcome in acute ischemic stroke patients using propensity score matching (PSM). Study design and population Acute ischemic stroke patients were selected from prospectively collected hospital-based stroke registry. Because the purpose of this study was comparing two treatment strategies for statin treatment, patients with cardioembolic stroke subtype or other-etiology were excluded. Patients were allocated into two groups: Intensive treatment group (atorvastatin 80mg; IT) and conventional treatment group (atorvastatin 10-40mg or other lipid-lowering agent; CT). All the patients were prescribed for aspirin 300mg at admission except for the patients who were considered for thrombolysis. After admission, the patients were prescribed for antithrombotics according to the clinical decision of the attending physician. All other practice guidelines except management of dyslipidemia were followed for previously published guidelines for management of stroke patients. Detailed demographic factors, vascular risk factors, laboratory parameters and vascular imaging were recorded. The end points were composed of two parameters. First, early neurological deterioration (END) defined as 4 points or more deterioration of National Institute of Health Stroke Score (NIHSS) from admission to the seventh hospital day. In case of discharge before the seventh hospital day, NIHSS at discharge was substituted for that of the seventh hospital day. Second, favorable outcome was defined as 0-2 of modified Rankin Score (mRS) measured at 3 months from the onset of stroke. Because baseline characteristics between the groups was supposed to be different, propensity score matching was performed to adjust for potential selection biases and confounding. A logistic regression model was fitted relating treatment strategies (IT and CT) to pretreatment patient characteristics. For the comparison between IT and CT in terms of END and favorable outcome, McNemar test were performed. Results: Among the study population, data of 178 patients for IT and 218 patients for CT were collected. Between the groups, history of previous stroke, TOAST classification, and previous medication of clopidogrel showed significant difference. There was no significant difference of 90-day favorable outcome and END. After PSM, 116 patients for each group were selected. There was no significant difference of baseline characteristics between the groups after PSM. There was no significant difference between IT and CT in terms of 90-day favorable outcome (75.3% in IT and 78.4% in CT, p = 0.457) and END (IT 72.3%, CT 78.6%, p = 0.097). Conclusion In this study, effect of intensive lipid-lowering treatment in acute stroke patients was negligible in terms of early functional outcome.