Endovascular treatment for anterior circulation ischaemic stroke is effective and safe within a 6 h window. MR CLEAN-LATE aimed to assess efficacy and safety of endovascular treatment for patients treated in the late window (6–24 h from symptom onset or last seen well) selected on the basis of the presence of collateral flow on CT angiography (CTA). MR CLEAN-LATE was a multicentre, open-label, blinded-endpoint, randomised, controlled, phase 3 trial done in 18 stroke intervention centres in the Netherlands. Patients aged 18 years or older with ischaemic stroke, presenting in the late window with an anterior circulation large-vessel occlusion and collateral flow on CTA, and a neurological deficit score of at least 2 on the National Institutes of Health Stroke Scale were included. Patients who were eligible for late-window endovascular treatment were treated according to national guidelines (based on clinical and perfusion imaging criteria derived from the DAWN and DEFUSE-3 trials) and excluded from MR CLEAN-LATE enrolment. Patients were randomly assigned (1:1) to receive endovascular treatment or no endovascular treatment (control), in addition to best medical treatment. Randomisation was web based, with block sizes ranging from eight to 20, and stratified by centre. The primary outcome was the modified Rankin Scale (mRS) score at 90 days after randomisation. Safety outcomes included all-cause mortality at 90 days after randomisation and symptomatic intracranial haemorrhage. All randomly assigned patients who provided deferred consent or died before consent could be obtained comprised the modified intention-to-treat population, in which the primary and safety outcomes were assessed. Analyses were adjusted for predefined confounders. Treatment effect was estimated with ordinal logistic regression and reported as an adjusted common odds ratio (OR) with a 95% CI. This trial was registered with the ISRCTN, ISRCTN19922220. Between Feb 2, 2018, and Jan 27, 2022, 535 patients were randomly assigned, and 502 (94%) patients provided deferred consent or died before consent was obtained (255 in the endovascular treatment group and 247 in the control group; 261 [52%] females). The median mRS score at 90 days was lower in the endovascular treatment group than in the control group (3 [IQR 2–5] 4 [2–6]), and we observed a shift towards better outcomes on the mRS for the endovascular treatment group (adjusted common OR 1·67 [95% CI 1·20–2·32]). All-cause mortality did not differ significantly between groups (62 [24%] of 255 patients 74 [30%] of 247 patients; adjusted OR 0·72 [95% CI 0·44–1·18]). Symptomatic intracranial haemorrhage occurred more often in the endovascular treatment group than in the control group (17 [7%] four [2%]; adjusted OR 4·59 [95% CI 1·49–14·10]). In this study, endovascular treatment was efficacious and safe for patients with ischaemic stroke caused by an anterior circulation large-vessel occlusion who presented 6–24 h from onset or last seen well, and who were selected on the basis of the presence of collateral flow on CTA. Selection of patients for endovascular treatment in the late window could be primarily based on the presence of collateral flow. Collaboration for New Treatments of Acute Stroke consortium, Dutch Heart Foundation, Stryker, Medtronic, Cerenovus, Top Sector Life Sciences & Health, and the Netherlands Brain Foundation.

中文翻译：

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荷兰缺血性卒中和侧枝循环 CT 血管造影 (MR CLEAN-LATE) 患者在 6-24 小时后进行血管内治疗与不进行血管内治疗：一项多中心、开放标签、盲终点、随机、对照、3 期试验

前循环缺血性卒中的血管内治疗在 6 小时内有效且安全。MR CLEAN-LATE 旨在评估根据 CT 血管造影 (CTA) 上是否存在侧支血流而选择的晚期窗口（症状出现后 6-24 小时或最后一次观察良好）接受治疗的患者的血管内治疗的有效性和安全性。MR CLEAN-LATE 是一项多中心、开放标签、盲终点、随机、对照、3 期试验，在荷兰 18 个卒中干预中心进行。纳入的患者年龄为 18 岁或以上，患有缺血性卒中，在晚期窗口出现 CTA 上的前循环大血管闭塞和侧枝循环，并且美国国立卫生研究院卒中量表的神经功能缺损评分至少为 2。符合晚窗血管内治疗资格的患者根据国家指南（基于 DAWN 和 DEFUSE-3 试验得出的临床和灌注成像标准）进行治疗，并排除在 MR CLEAN-LATE 入组之外。除最佳药物治疗外，患者还被随机分配（1:1）接受血管内治疗或不接受血管内治疗（对照）。随机化是基于网络的，区块大小从 8 到 20 不等，并按中心分层。主要结果是随机化后 90 天的改良 Rankin 量表 (mRS) 评分。安全性结果包括随机分组后 90 天的全因死亡率和有症状的颅内出血。所有随机分配的提供延期同意或在获得同意之前死亡的患者均包含修改后的意向治疗人群，其中对主要结局和安全性结局进行了评估。针对预定义的混杂因素调整了分析。治疗效果通过序数逻辑回归进行评估，并报告为调整后的共同比值比 (OR)，CI 为 95%。该试验已在 ISRCTN 注册，ISRCTN19922220。2018年2月2日至2022年1月27日期间，535名患者被随机分配，其中502名（94%）患者提供了延期同意或在获得同意之前死亡（血管内治疗组255名，对照组247名；261名患者） 52%]女性）。血管内治疗组 90 天时的中位 mRS 评分低于对照组 (3 [IQR 2–5] 4 [2–6])，并且我们观察到血管内治疗的 mRS 结局向更好的方向转变组（调整后的共同 OR 1·67 [95% CI 1·20–2·32]）。各组之间的全因死亡率没有显着差异（255 名患者中的 62 名患者 [24%]，247 名患者中的 74 名患者 [30%]；调整后 OR 0·72 [95% CI 0·44–1·18]）。血管内治疗组中症状性颅内出血的发生率高于对照组（17 [7%] 4 [2%]；调整后 OR 4·59 [95% CI 1·49–14·10]）。在这项研究中，血管内治疗对于前循环大血管闭塞引起的缺血性卒中患者有效且安全，这些患者在发病后 6-24 小时内就诊或最后一次就诊情况良好，并且根据 CTA 上是否存在侧支血流进行选择。选择在晚期窗口进行血管内治疗的患者主要基于侧支血流的存在。急性中风新疗法联盟、荷兰心脏基金会、Stryker、美敦力、Cerenovus、Top Sector 生命科学与健康以及荷兰大脑基金会的合作。