To bridge or not to bridge: summary of the new evidence in endovascular stroke treatment

Recently published summaries and meta-analyses of four randomised controlled trials (RCTs)1-5 comparing direct mechanical thrombectomy (dMT) and bridging therapy with intravenous (IV) thrombolytics (alteplase) suggested that dMT is non-inferior to bridging therapy to achieve good functional outcome 3 months after stroke (modified Rankin Score 0-2) with the non-inferiority margin (NIM) <-5%.5-7 However, there were considerable limitations in generalisability as three of the RCTs were performed in the Asian population, and the alteplase dose was different between studies (0.6 mg/kg or 0.9 mg/kg). Recently, preliminary results of two further RCTs (SWIFT-DIRECT8 and DIRECT-SAFE9) were presented at the 2021 World Stroke Congress and other conferences. Both RCTs (SWIFT-DIRECT and DIRECT-SAFE) compared dMT with bridging therapy, assuming a NIM of 12% and 10%, respectively. Both failed to confirm the non-inferiority of dMT approach, although it is worth noting that DIRECT-SAFE was terminated early in June 2021, with only 293 out of planned 780 participants recruited, following the publications of the other RCTs' results.9