Endovascular treatment of low NIHSS score(<6) combined with large vessel occlusion: a meta-analysis

At present, there is still debate about the treatment strategies for acute ischemic stroke patients with low National Institute of Health Stroke Scale (NIHSS) scores (<6 points) and large vessel occlusion (LVO). Our objective is to assess whether endovascular treatment (EVT) could be beneficial in acute ischemic stroke patients with low NHISS scores and LVO.

We searched the PubMed, Embase, Cochrane Library, and Web of Science databases to obtain articles related to EVT for patients with low NHISS score with LVO until 1 January 2024. The primary outcome was a good functional outcome (modified Rankin Scale [mRS] 0-2). Effect sizes were computed as risk ratio (RR) with random-effects or fixed-effects models. The quality of articles was evaluated through the Cochrane risk assessment tool and the Newcastle-Ottawa Scale.

A total of 2,275 articles were obtained through the search, and articles that did not meet the inclusion criteria were excluded after review of the title, abstract, and full text. Finally, 2 randomized controlled trials (RCTs) and 22 cohort studies met the inclusion criteria. In the EVT group, 77.8% of patients achieved a good functional outcome, while 77.1% of patients achieved functional independence in the best medical treatment (BMT) group. EVT was not associated with excellent functional outcome (mRS 0-1; risk ratio 1.04 [95% CI, 0.97-1.11]) or with a good functional outcome (mRS 0-2; risk ratio 1.00 [95% CI, 0.95-1.04]). Symptomatic intracranial hemorrhage was more common in patients receiving EVT (risk ratio 2.82 [95% CI, 2.18-3.65]). There was no correlation between EVT and 3-month mortality (risk ratio 1.15 [95% CI, 0.93-1.43]).

This meta-analysis shows that, in patients with low NIHSS score combined with LVO, EVT did not demonstrate clear improvement in neurologic outcomes but was associated with an increased incidence of symptomatic intracranial hemorrhage (sICH) compared to BMT.