Bridging versus Direct Mechanical Thrombectomy in Acute Ischemic Stroke: A Subgroup Pooled Meta-Analysis for Time of Intervention, Eligibility, and Study Design

Abstract

Background and Aim: The risk/benefit profile of intravenous thrombolysis (IVT) prior to endovascular thrombectomy (EVT) in acute ischemic stroke is still unclear. We provide a systematic review and meta-analysis including studies comparing direct EVT (dEVT) vs. bridging treatment (IVT + EVT), defining the impact of treatment timing and eligibility to IVT on functional status and mortality. Methods: Protocol was registered with PROSPERO (CRD42019135915) and followed PRISMA guidelines. PubMed, EMBASE, and Cochrane Central were searched for randomized controlled trials (RCTs), retrospective, and prospective studies comparing IVT + EVT vs. dEVT in adults (≥18) with acute ischemic stroke. Primary endpoint was functional independence at 90 days (modified Rankin Scale 2a), (ii) mortality, and (iii) symptomatic intracranial hemorrhage (sICH). Subgroup analysis was performed according to study type, eligibility to IVT, and onset-to-groin timing (OGT), stratifying studies for similar OGT. ORs for endpoints were pooled with meta-analysis and compared between reperfusion strategies. Results: Overall, 35 studies were included (n = 9,117). No significant differences emerged comparing patients undergoing dEVT and bridging treatment for gender, hypertension, diabetes, National Institute of Health Stroke Scale score at admission. Regarding primary endpoint, IVT + EVT was superior to dEVT (OR 1.44, 95% CI 1.22–1.69, p < 0.001, p_{heterogeneity}Conclusions: Compared to dEVT, IVT + EVT associates with better functional outcome and lower mortality. Post hoc data from RCTs point to substantial equivalence of reperfusion strategies. Therefore, an adequately powered RCTs comparing dEVT versus IVT + EVT are warranted.