Outcome of endovascular therapy in stroke with large vessel occlusion and mild symptoms

Objective To compare outcomes after endovascular therapy (EVT) and IV thrombolysis (IVT) in patients with stroke with emergent large vessel occlusion (LVO) and mild neurologic deficits. Methods This was a retrospective analysis of patients from the Swiss Stroke Registry with admission NIH Stroke Scale score <= 5 and LVO treated by EVT (+/- IVT) vs IVT alone. The primary endpoint was favorable functional outcome (modified Rankin Scale [mRS] score 0-1) at 3 months. Secondary outcomes were independence (mRS score 0-2), mRS score (ordinal shift analysis), and survival with high disability (mRS score 4-5). Safety endpoints were mortality and symptomatic hemorrhage. Results Of 11,356 patients, 312 met the criteria and propensity score method matched 108 in each group. A comparably large proportion of patients with EVT and IVT had favorable outcome (63% vs 65.7% respectively; odds ratio 0.94, 95% confidence interval 0.51-1.72; p = 0.840). Patients with EVT showed a nonsignificant trend toward higher mRS score at 3 months (p = 0.717), while the proportion of surviving patients with high disability was comparably very low in both groups (p = 0.419). Mortality was slightly higher among those with EVT (9.3% vs 2.8%; p = 0.06), and symptomatic intracranial hemorrhage was a rare event in both groups (2.8% vs 0%; p = 0.997). Conclusions In acute ischemic stroke, EVT and IVT appear similarly effective in achieving favorable outcome at 3 months for patients with LVO and mild neurologic symptoms. EVT might be marginally inferior to IVT regarding outcome across all levels of disability and mortality. Further studies are required to determine whether certain subgroups of patients with LVO and mild symptoms benefit from EVT. Classification of evidence This study provides Class III evidence that patients with LVO and mild symptoms receiving either EVT or IVT had similar favorable functional outcomes at 3 months.