Supplementary Material for: Prestroke Antiplatelet Agents in First-Time Ischemic Stroke Are Related to Subtypes

<b><i>Background:</i></b> It is not well known whether prestroke antiplatelet agents (PAs) are associated with the subtypes of ischemic stroke. <b><i>Methods:</i></b> We screened patients in a hospital-based stroke registry. Patients who were admitted with a diagnosis of first-time ischemic stroke within 5 days of symptom onset were included. Ischemic stroke subtypes were classified in accordance with the Trial of ORG 10172 in Acute Stroke Treatment classification based on stroke mechanism: large-artery atherosclerosis (LA), cardioembolism (CE), small vessel occlusion (SVO), other determined (OC) or undetermined causes (UC). Multinomial logistic regression analyses were performed to evaluate the effect of PA on stroke subtypes before and after propensity score matching. <b><i>Results:</i></b> Among 3,025 patients, 748 (24.7%) were taking antiplatelet agents prior to stroke. After propensity score matching, 1,190 patients were ultimately included. The PA group was associated with strokes caused by SVO rather than LA in multinomial logistic regression of an unmatched dataset. However, multivariable analysis after propensity score matching demonstrated that PA use was associated with a higher probability of SVO and CE (OR 2.05, p &lt; 0.001 and OR 1.62, p = 0.05, respectively) compared with LA. <b><i>Conclusions:</i></b> PAs were associated with specific index stroke subtypes.

**<i>背景：</i>** 目前尚不明确卒中前抗血小板药物（prestroke antiplatelet agents，PAs）是否与缺血性脑卒中亚型存在关联。**<i>方法：</i>** 本研究依托医院脑卒中登记库筛选研究对象，纳入症状发作5天内入院且确诊为首次缺血性脑卒中的患者。依据《急性脑卒中治疗中ORG 10172试验》（Trial of ORG 10172 in Acute Stroke Treatment，简称TOAST）分型标准，按发病机制将缺血性脑卒中亚型分为大动脉粥样硬化型（large-artery atherosclerosis，LA）、心源性栓塞型（cardioembolism，CE）、小血管闭塞型（small vessel occlusion，SVO）、其他明确病因型（other determined，OC）及不明原因型（undetermined causes，UC）。分别在倾向得分匹配前后，采用多项logistic回归分析评估抗血小板药物对脑卒中亚型的影响。**<i>结果：</i>** 本研究共纳入3025例患者，其中748例（24.7%）于脑卒中发病前使用了抗血小板药物。经倾向得分匹配后，最终纳入1190例患者。在未匹配数据集的多项logistic回归分析中，抗血小板药物组与小血管闭塞型脑卒中相关，而非大动脉粥样硬化型脑卒中。但经倾向得分匹配后的多变量分析显示，与大动脉粥样硬化型相比，使用抗血小板药物与小血管闭塞型（优势比OR=2.05，P<0.001）及心源性栓塞型（OR=1.62，P=0.05）脑卒中的发生概率显著升高。**<i>结论：</i>** 卒中前抗血小板药物与特定的本次缺血性脑卒中亚型存在关联。