Efficacy and safety of thrombectomy for acute ischaemic stroke in patients with pre-stroke mRS scores of 2-3: Real-world evaluation from an open-label, prospective, multicentre, observational study.

BACKGROUND: This study assessed the efficacy and safety of thrombectomy for acute ischaemic stroke in a population with pre-stroke modified Rankin scale (mRS) scores of 2-3 using real-world data. METHODS: Our sample set included 2313 consecutive patients enrolled in the Kanagawa Registry of Intravenous and Endovascular Treatment of Acute Ischemic Stroke registry between January 2018 and June 2020 in 40 stroke centres in Kanagawa Prefecture, Japan. Patients treated with intravenous tissue plasminogen activator (t-PA), thrombectomy, or both were included. Patients with pre-stroke mRS scores of 4-5 and those treated only with intra-arterial thrombolysis were excluded. The primary outcome of this study was an mRS score of 0-3 at 90 days after onset to assess the efficacy of thrombectomy for pre-stroke disabled individuals. We performed multivariate logistic regression analyses to investigate independent factors for a 90-day mRS score of 0-3. We also performed nearest-neighbour within-calliper matching between thrombectomy and t-PA only. RESULTS: After excluding patients meeting the exclusion criteria, we analysed data of 2136 consecutive patients, of which 315 (14.7%) had pre-stroke disabilities (mRS score 2-3). A 90-day mRS score of 0-3 was achieved by 33.3% of patients with pre-stroke mRS scores of 2-3. According to multivariate analysis, the National Institutes of Health Stroke Scale (NIHSS) score was an independent factor. Furthermore, after propensity-score matching, thrombectomy showed considerable superiority for achieving a 90-day mRS score of 0-3. CONCLUSION: Intravenous t-PA and especially thrombectomy were safe and effective for the population with pre-stroke disabilities, particularly for patients with low NIHSS scores.