Mechanical Thrombectomy Improves Functional Outcomes Independent of Pretreatment With Intravenous Thrombolysis.

BACKGROUND AND PURPOSE Endovascular intervention for emergent large-vessel occlusion (ELVO) has evolved rapidly during the past decade. The question of whether pretreatment with intravenous thrombolysis (IVT) has a significant impact on the functional outcome of patients with ELVO still remains unanswered. METHODS We conducted a systematic review and meta-analysis of all available randomized controlled trials evaluating the efficacy of endovascular therapy (ET) for acute ischemic stroke. We performed a mixed-effects subgroup analysis of the reported odds ratios on the association of ET (versus standard therapy) with 3-month functional outcome, stratified by pretreatment with IVT. RESULTS Six randomized controlled trials were included, comprising 1916 total patients (49.1% receiving ET with IVT pretreatment and 5.6% receiving ET without IVT pretreatment). In the subgroup analysis, ET was associated with a higher likelihood of better 3-month functional outcome in both the subgroup of patients with (odds ratio=1.83; 95% confidence interval, 1.37-2.44; P<0.001) and without (odds ratio=2.47; 95% confidence interval, 1.32-4.63; P=0.001) pretreatment with IVT. We documented no significant effect of IVT pretreatment on the 3-month functional outcome of patients with ELVO undergoing ET, suggesting that ET is effective in all patients with ELVO. Heterogeneity was documented in the IVT pretreatment subgroup (I(2)=68.3%; P for Cochran Q=0.014), but not in the subgroup that did not receive IVT pretreatment (I(2)=0%, P for Cochran Q=0.927). The risk of bias was considered to be generally low in the qualitative assessment of the included trials. CONCLUSIONS Our observation provides evidence and further reassurance to stroke clinicians regarding the efficacy of ET in ELVO independent of pretreatment with IVT.