Supplementary Material for: Lactate Dehydrogenase Predicts Hemorrhagic Transformation in Patients with Acute Ischemic Stroke

Introduction: Hemorrhagic transformation (HT) is a severe but frequent complication of acute ischemic stroke (AIS). This study aimed to evaluate the relationship between serum LDH levels and HT. Methods: We retrospectively included 542 AIS patients with HT and 1091 age and gender-matched patients without HT. Demographic and clinical data were obtained from medical records, and blood samples were obtained within 24 hours after admission. The characteristics of groups were compared. With the receiver operating characteristic curve (ROC) analysis, we assessed the discriminating capacity of LDH levels in predicting HT in patients with AIS. The logistic regression model was used to determine the connection between LDH and HT. Results: The HT group had considerably higher LDH levels than the non-HT group [263.0 (216.0-323.3) U/L vs. 178.0 (162.0-195.0) U/L, P < 0.001]. We also observed that the levels of LDH in the parenchymal hemorrhage (PH) subgroup were significantly higher than those in the hemorrhagic infarction (HI) subgroup [281.0 (230.0-340.0) U/L vs. 258.0 (209.0-311.0) U/L, P < 0.001]. The area under the ROC curve (AUC) of LDH was 0.890 (95% CI 0.874-0.905, P < 0.001). Besides, logistic regression revealed that high LDH levels (LDH > 215 U/L) showed a higher risk of HT [odds ratio (OR) = 10.958, 95% confidence level (CI) 7.964-15.078, P < 0.001]. Conclusion: High LDH levels were linked with an increased risk of HT in AIS patients. Practical measures should be considered in patients with increased LDH levels (LDH > 215 U/L).

引言：出血性转化（Hemorrhagic transformation, HT）是急性缺血性脑卒中（acute ischemic stroke, AIS）一种严重且常见的并发症。本研究旨在探讨血清乳酸脱氢酶（lactate dehydrogenase, LDH）水平与HT之间的关联。
方法：本研究回顾性纳入542例合并HT的AIS患者，以及1091例年龄、性别匹配的未合并HT患者。从电子病历中提取人口统计学与临床资料，并于患者入院后24小时内采集血液样本。对两组患者的临床特征进行比较分析。通过受试者工作特征曲线（receiver operating characteristic curve, ROC）评估LDH水平预测AIS患者发生HT的区分能力；采用logistic回归模型分析LDH水平与HT之间的相关性。
结果：HT组患者的LDH水平显著高于非HT组[263.0（216.0~323.3）U/L vs. 178.0（162.0~195.0）U/L，P < 0.001]。此外，脑实质出血（parenchymal hemorrhage, PH）亚组患者的LDH水平亦显著高于出血性梗死（hemorrhagic infarction, HI）亚组[281.0（230.0~340.0）U/L vs. 258.0（209.0~311.0）U/L，P < 0.001]。LDH的ROC曲线下面积（area under the ROC curve, AUC）为0.890（95%置信区间CI：0.874~0.905，P < 0.001）。Logistic回归分析显示，高LDH水平（LDH > 215 U/L）与HT发生风险升高显著相关[优势比（odds ratio, OR）=10.958，95%置信区间CI：7.964~15.078，P < 0.001]。
结论：AIS患者的高LDH水平与HT发生风险升高存在显著关联。对于LDH水平升高（LDH > 215 U/L）的患者，应考虑采取针对性临床干预措施。