Background

Direct mechanical thrombectomy (dMT) may result in similar outcomes compared to a bridging approach with intravenous thrombolysis (IVT+MT) in acute ischaemic stroke. Recent randomised controlled trials (RCTs) have varied in their design and non-inferiority margins (NIM).

Aim

We sought to meta-analyse accumulated trial data to assess the difference and non-inferiority in clinical and procedural outcomes between dMT and bridging therapy.

Summary of review

We conducted a systematic review of electronic databases following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Random effects meta-analyses were conducted for the pooled data. The primary outcome was good functional outcome at 90 days (modified Rankin Scale (mRS)≤2). Secondary outcomes included excellent functional outcome (mRS≤1), mortality, any intracranial haemorrhage (ICH), symptomatic ICH, successful reperfusion (TICI2b) and procedure-related complications. Four RCTs comprising 1633 patients (817 dMT, 816 bridging therapy) were included. There were no statistical differences for the 90-day good functional outcome (OR=1.02, 95%CI 0.84-1.25, p=0.54, I2=0%), and the absolute risk difference was 1% (95% CI −4% to 5%). The lower 95% CI falls within the strictest NIM of -10% among included RCTs. dMT reduced the odds of successful reperfusion (OR=0.76, 95%CI 0.60-0.97, p=0.03, I2=0%) and any ICH (OR=0.65, 95%CI 0.49-0.86, p=0.003, I2=38%). There was no difference in the remaining secondary outcomes. The risk of bias for all studies was low.

Conclusion

The combined trial data assessing dMT versus bridging therapy showed no difference in improving good functional outcome. The wide non-inferiority thresholds set by individual trials are in contrast with the clinical consensus on minimally important differences. However, our pooled analysis indicates non-inferiority of dMT with a 4% margin of confidence. The application of these findings is limited to patients presenting directly to MT-capable centres and real-world workflow times may differ against those achieved in a trial setting.

背景

在急性缺血性卒中中，与静脉溶栓（IVT+MT）桥接方法相比，直接机械取栓（dMT）可能产生相似的结果。最近的随机对照试验 (RCT) 在设计和非劣效性边际 (NIM) 方面各不相同。

目的

我们试图对累积的试验数据进行荟萃分析，以评估 dMT 和桥接治疗之间临床和程序结果的差异和非劣效性。

审查总结

我们按照系统评价和元分析的首选报告项目 (PRISMA) 指南对电子数据库进行了系统评价。对汇总数据进行了随机效应荟萃分析。主要结果是 90 天时良好的功能结果（改良的 Rankin 量表 (mRS) ≡2）。次要结果包括出色的功能结果 (mRS??1)、死亡率、任何颅内出血 (ICH)、有症状的 ICH、成功再灌注 (TICIï??³2b) 和手术相关并发症。包括 1633 名患者（817 名 dMT，816 名桥接疗法）的四项 RCT。90 天良好功能结局无统计学差异（OR=1.02, 95%CI 0.84-1.25, p=0.54, I2=0%），绝对风险差异为 1%（95% CI ?? ??4% 到 5%）。在纳入的 RCT 中，较低的 95% CI 属于 -10% 的最严格 NIM。dMT 降低了再灌注成功的几率（OR=0.76, 95%CI 0.60-0.97, p=0.03, I2=0%）和任何 ICH（OR=0.65, 95%CI 0.49-0.86, p=0.003, I2=38 %）。其余次要结局没有差异。所有研究的偏倚风险都很低。

结论

评估 dMT 与桥接疗法的联合试验数据显示，在改善良好的功能结果方面没有差异。个别试验设定的广泛的非劣效性阈值与关于最小重要差异的临床共识形成对比。然而，我们的汇总分析表明 dMT 具有 4% 的置信区间的非劣效性。这些发现的应用仅限于直接向具有 MT 能力的中心就诊的患者，现实世界的工作流程时间可能与在试验环境中实现的工作流程时间不同。