Abstract 65: Effect of Prestroke Statin Use on Stroke Severity and Early Functional Recovery

Abstract

Background: Experimental studies suggest that prestroke statin treatment has dual effect of neuroprotection during ischemia and neurorestoration after ischemic injury. However, human clinical stroke studies of small to modest sample sizes have shown inconsistent results regarding these effects. Methods: We analyzed the Clinical Research Center for Stroke-5 data set for patients hospitalized with acute ischemic stroke in 12 academic hospitals between April 1, 2008 and January 31, 2012. Primary endpoint was the initial stroke severity as measured by the National Institutes of Health Stroke Scale (NIHSS) score. Secondary endpoints were mRS 0-2 proportion and overall distribution of mRS outcomes at discharge. Propensity score (PS) analysis were used to adjust baseline characteristics between statin users and non-users in addition to multivariable analyses. Results: Among 8,340 patients included in this study (age, 67±13 years; men, 59.6%; initial median NIHSS score [interquartile range, IQR], 3 [2-7]), 964 patients (11.6%) were taking statins before the index stroke. Prestroke statin users had significantly lesser initial NIHSS score than that of non-users (unadjusted mean [95% CI], 4.6 [4.3-4.9] versus 5.4[5.3-5.6], p <0.0001; median [IQR]), 3 (IQR, 1-6) versus 3 (IQR, 2-7) , p <0.0001).The difference remained significant after adjustment for covariates (adjusted mean, 6.0 [5.5-6.5] versus 6.6 [6.1-7.0]; p=0.0062) as well as PS-matched cohort (adjusted mean, 4.8[4.3-5.2] versus 5.4[5.1-5.7], p=0.0298). After adjusting for covariates including initial NIHSS score, statin users had more frequent mRS 0-2 outcome (adjusted OR [95% CI], 1.50 [1.21-1.86]; p=0.0002) and greater favorable shift on the mRS score at discharge than those of non-users (adjusted OR [95% CI], 1.26 [1.08-1.48]; p=0.003). In PS-matched cohort, similar associations were also found for dichotomized outcomes (adjusted OR [95% CI], 1.55 [1.22-1.97]; p=0.0003) and for ordinal outcomes (adjusted OR [95% CI], 1.28 [1.07-1.52]; p=0.0058). Conclusions: Prestroke statin use was independently associated with lesser stroke severity at presentation and better early functional outcome, suggesting dual effect of neuroprotection and neurorestoration in human clinical strokes.