Supplementary Material for: Early Blood Pressure Reduction in Acute Ischemic Stroke with Various Severities: A Subgroup Analysis of the CATIS Trial

Background: Clinical trials have generally showed a neutral effect of blood pressure (BP) reduction on clinical outcomes among acute ischemic stroke patients. We conducted a prespecified subgroup analysis to assess whether disease severity modifies the effect of early antihypertensive treatment on death and disability among patients with acute ischemic stroke. Methods: In the China Antihypertensive Trial in Acute Ischemic Stroke, 4,071 patients with acute ischemic stroke and elevated BP were randomly assigned to receive antihypertensive treatment or to discontinue all hypertension medications within 48 h of symptom onset. The primary outcome was a combination of death and major disability at 14 days or hospital discharge. In this subgroup analysis, participants were categorized into 3 groups according to their baseline NIH Stroke Scale (NIHSS) scores (0-4, 5-15, or ≥16). Results: At 24 h after randomization, mean systolic BP differences (95% CIs) were -8.5 (-10.0 to -7.1), -9.8 (-11.4 to -8.3), and -9.1 (-14.4 to -3.8) mm Hg between the treatment and control groups (all p values Conclusion: Early BP reduction with antihypertensive medications did not reduce or increase the risk of death, major disabilities, recurrent instances of stroke, and vascular events in acute ischemic stroke patients with a variety of disease severities.

研究背景：既往临床试验普遍显示，急性缺血性卒中患者接受血压（blood pressure, BP）降低治疗对临床结局无显著影响。本研究开展预先设定的亚组分析，旨在评估疾病严重程度是否会改变早期降压治疗对急性缺血性卒中患者死亡与残疾风险的影响。
研究方法：本研究依托中国急性缺血性卒中降压试验（China Antihypertensive Trial in Acute Ischemic Stroke），共纳入4071例急性缺血性卒中伴血压升高患者，在症状发作后48小时内随机分配至降压治疗组或停用全部降压药物的对照组。本研究的主要结局为发病14天或出院时死亡与重度残疾的复合终点。本次亚组分析中，受试者按照基线美国国立卫生研究院卒中量表（NIH Stroke Scale, NIHSS）评分被分为3组：0~4分、5~15分及≥16分。
研究结果：随机分组后24小时，治疗组与对照组的平均收缩压差值（95%置信区间，95% CIs）分别为-8.5（-10.0~-7.1）mmHg、-9.8（-11.4~-8.3）mmHg及-9.1（-14.4~-3.8）mmHg（所有P值[原文此处未完整给出]）。
研究结论：对于不同疾病严重程度的急性缺血性卒中患者，早期采用降压药物降低血压，既未降低也未增加其死亡、重度残疾、卒中复发及血管事件的风险。