Abstract: Objective  To investigate the risk factors of hemorrhagic transformation (HT) after ischemic stroke (IS).
Methods  The in-hospital IS patients from the China Stoke Center Alliance (CSCA) registry database from August 1, 2015, to July 31, 2019 were enrolled in the retrospective analysis. According to the presence of HT or not after IS during hospitalization, all the subjects were divided into IS with HT group and IS without HT group. Differences in demographics, unhealthy life behaviors, disease history, in-hospital treatments, past and in-hospital medications and disease severity score of NIHSS were collected between the groups. A multivariate Poisson regression model was used to identify risk factors of HT after IS. 
Results  A total of 828 652 IS patients were enrolled in this study, with a median age of 67 years and 518 063 (62.5%) males, and the median NIHSS score was 3 points. Multivariate analysis showed that age (RR 1.01, 95%CI 1.00-1.01), stroke severity (RR 1.06, 95%CI 1.05-1.06), atrial fibrillation (RR 2.56, 95%CI 2.35-2.78), myocardial infarction (RR 1.33, 95%CI 1.11-1.60), peripheral vascular disease (RR 1.26, 95%CI 1.06-1.51), in-hospital thrombolysis treatment (RR 2.21, 95%CI 2.05-2.37), thrombectomy (RR 2.02, 95%CI 1.79-2.28), previous use of anticoagulants (RR 0.79, 95%CI 0.70-0.90), previous use of antiplatelet drugs (RR 0.87, 95%CI 0.81-0.93), in-hospital anticoagulant therapy (RR 0.57, 95%CI 0.51-0.65) and in-hospital antiplatelet therapy (RR 0.22, 95%CI 0.20-0.23) were independent risk factors for HT after IS.
Conclusions  HT is a common complication in IS patients. Older age, stroke severity, atrial fibrillation, myocardial infarction, peripheral vascular disease, in-hospital thrombolysis treatment and thrombectomy were independent risk factors for HT after IS. Prior and in-hospital use of antithrombotic drugs were protective factors for HT.

Key words: Ischemic stroke; Hemorrhagic transformation; Risk factor

摘要： 目的 调查中国缺血性卒中（ischemic stroke，IS）患者出血转化（hemorrhagic transformation，HT）的危险因素。
方法 本研究数据来源于中国卒中中心联盟（China Stoke Center Alliance，CSCA）多中心登记数据库2015年8月1日—2019年7月31日连续入组的IS患者。按照是否发生HT，研究对象被划分为HT组和无HT组。收集组间的人口学特征、不良生活行为、既往疾病史、院内治疗、既往和院内用药以及疾病严重程度的差异。对上述指标进行多因素Poisson回归，以分析HT的危险因素。 
结果 本研究纳入828 652例IS患者，男性518 063例（62.5%），年龄中位数67岁，入院NIHSS评分的中位数为3分。多因素分析发现，年龄（RR 1.01，95%CI 1.00～1.01）、卒中严重程度（RR 1.06，95%CI 1.05～1.06）、心房颤动（RR 2.56，95%CI 2.35～2.78）、心肌梗死（RR 1.33，95%CI 1.11～1.60）、周围血管病（RR 1.26，95%CI 1.06～1.51）、院内溶栓（RR 2.21，95%CI 2.05～2.37）、取栓治疗（RR 2.02，95%CI 1.79～2.28）、既往使用抗凝药物（RR 0.79，95%CI 0.70～0.90）、既往使用抗血小板药物（RR 0.87，95%CI 0.81～0.93）、院内抗凝治疗（RR 0.57，95%CI 0.51～0.65）和院内抗血小板治疗（RR 0.22，95%CI 0.20～0.23）是HT的独立影响因素（均P<0.01）。
结论 HT是IS患者较为常见的并发症，高龄、卒中严重程度、心房颤动、心肌梗死、周围血管病、院内溶栓和取栓治疗是HT的独立危险因素。既往及院内使用抗栓药物是HT的保护因素。

关键词: 缺血性卒中; 出血转化; 影响因素