Effect of Premorbid Antiplatelet Medication Use on Delayed Cerebral Ischemia After Aneurysmal Subarachnoid Hemorrhage: A Propensity Score-matched Study

Introduction Delayed cerebral ischemia (DCI) is a serious complication of aneurysmal subarachnoid hemorrhage (aSAH) and a major predictor of poor functional outcomes in patients surviving the initial insult. Several theories have postulated that platelet activation, microthrombi formation, and subsequent vasospasm are mechanisms involved. We, therefore, assessed the effect of premorbid antiplatelet medication (APM) use on discharge functional outcomes and cerebral infarction due to DCI in patients presenting with aSAH. Methods Retrospective analysis of patients admitted to a single US center with aSAH from 2007 to 2016 was performed. Patients who were receiving APM prior to admission were then matched to those who did not receive them using nearest-neighbor propensity-score-matching (PSM) controlling for the following variables: age, hypertension, smoking status, Hunt-&-Hess classification, and management type. Results Out of the 267 patients identified, 38 (14.2%) were on APMs when admitted. On univariate analysis, patients on APM were older (p < 0.001) and more likely to be hypertensive (p = 0.005). Modified Rankin Scale (mRS) at discharge was significantly worse for patients on APMs compared to those who were not (mRS 3-6 in 55.3% vs 32.7%; p = 0.007). No significant difference in cerebral infarction due to DCI was found (p = 0.82). PSM resulted in 20 patients in the APMs group and 20 patients in the comparison group. After matching, no significant difference was found in discharge mRS (p = 0.56) and cerebral infarction due to DCI (p = 0.7). Conclusion This study identified no significant effect of admission APMs on discharge functional outcomes and cerebral infarction due to DCI in aSAH patients after matching.