Endovascular Therapy vs Thrombolysis for Stroke With Large Vessel Occlusion and Mild Symptoms

In patients with mild neurologic deficiency secondary to acute ischemic stroke with large vessel occlusion (LVO), functional outcomes at 3 months were comparable following endovascular therapy (EVT) or intravenous thrombolysis (IVT), according to study results published in Neurology.

While EVT was found to be the most effective modality to obtain functional independence in patients with acute ischemic stroke with LVO of the anterior circulation and moderate to severe stroke symptoms, the outcomes of this modality in patients with mild symptoms are not clear.

The goal of the current study was to compare the efficacy and safety of EVT with or without IVT compared with IVT alone in patients with acute stroke, LVO, and mild symptoms (National Institute of Health Stroke Scale score ≤5).  

The multicenter retrospective study included data from the Swiss Stroke Registry, a national web-based registry designed to collect data on patients with ischemic stroke, hospitalized at certified centers across Switzerland. The primary outcome was favorable functional outcome, defined as modified Rankin Scale (mRS) score of 0 to 1 at 3 months following EVT vs IVT.

Secondary functional outcomes at 3 months were the percentage of functionally independent patients (eg, mRS score 0 to 2), global mRS assessment, and percentage of patients surviving with high disability (eg, mRS score 4–5). Safety end points were mortality at 3 months and occurrence of symptomatic intracranial hemorrhage.

Of 11,356 patients with acute ischemic stroke hospitalized between January 2014 and July 2017, the study cohort included 312 patients: 137 following EVT (68 following EVT alone, 69 following EVT with IVT) and 175 following IVT only. After propensity score matching, 108 subjects in each group were included in the analyses.

The percentage of patients with a favorable outcome at 3 months was not statistically significantly different between the groups: 63% following EVT and 65.7% after IVT.

The mRS score shift analysis showed overall a non-significant trend toward greater mRS score in the group of patients following EVT compared with patients following IVT (adjusted odds ratio 1.09; 95% CI, 0.67-1.78; P =.717), while in both groups the rates of survival with high disability were low.

Mortality rates at 3 months were higher in the group of patients after EVT compared with patients following IVT, but the difference was not statistically significant (9.3% vs 2.8%; P =.06). Symptomatic intracranial hemorrhage was rare in both groups and not significantly different between the groups.

The researchers noted that the study has several limitations, including its non-randomized design, the possibility for uncontrolled confounders, and the lack of a control group (without EVT or IVT). Investigators also noted missing information on radiologic outcomes as follow-up vessel imaging is not routinely performed after IVT.

“Our study is relevant for the ongoing debate concerning the suitability of EVT as optimal treatment for [acute ischemic stroke] with LVO and mild deficits and supports the need for further research to evaluate whether certain subgroups of patients with LVO and mild symptoms benefit from EVT,” concluded the researchers.

Reference

Manni C, Disanti G, Bianco G, et al. Outcome of endovascular therapy in stroke with large vessel occlusion and mild symptoms. [published online October 7, 2019]. Neurology. doi:10.1212/WNL.0000000000008362