Pre-stroke functional status and prognosis following mechanical thrombectomy: Systematic review and meta-analysis

IntroductionMechanical thrombectomy (MT) is an endovascular approach applicable to large- and medium-vessel occlusion in the context of ischemic stroke (IS), with recanalization rates superior to 80% and favorable clinical outcomes. However, its benefits in patients with pre-existing functional disability remain unclear because these individuals are typically excluded from randomized controlled trials (RCTs). This systematic review and meta-analysis therefore aimed to assess how pre-stroke functional status influences key prognostic outcomes after MT.MethodologyPubMed, Embase, Scopus, Web of Science, and Cochrane Library databases were searched for English studies published from inception to September 2025. Observational cohorts and RCTs were included if they evaluated patients with IS treated with MT, comparing outcomes (functional outcomes, recanalization, complications, and mortality) between patients with and without pre-stroke disability (PD and NPD, respectively). Disability was mainly defined as a pre-stroke modified Rankin Scale (mRS) ≥2 or ≥3, and analyses were stratified accordingly. Data were pooled using a random-effects model, and heterogeneity was explored with Baujat plots and leave-one-out analyses.ResultsThis review included 12 studies comprising 26,444 patients, of whom 2,837 had PD and 23,607 had NPD. Most studies defined PD as a pre-stroke mRS ≥3. Patients with PD had higher rates of diabetes (28.9% vs 18.5%), hypertension (78.9% vs 66.0%), and atrial fibrillation (46.7% vs 29.4%). In contrast, NIHSS, ASPECTS, occlusion site, and time to treatment were similar between groups. Intravenous thrombolysis was less frequently administered in the PD group (33.8% vs 46.9%). No significant difference was observed in favorable functional outcomes between patients with PD and NPD (OR = 0.68; 95% CI: 0.39-1.16). Otherwise, 90-day mortality was higher in PD patients (OR = 2.75; 95% CI: 2.38-3.18). Finally, the risk of symptomatic intracranial hemorrhage and the rate of successful recanalization did not differ significantly between groups (OR = 1.19; 95% CI: 0.98-1.43, and OR = 0.89; 95% CI: 0.71-1.11, respectively).ConclusionPre-stroke disability was not significantly associated with functional outcomes or reduced recanalization rates after mechanical thrombectomy, although the substantial heterogeneity in functional outcomes warrants cautious interpretation. Pre-stroke disability was associated with higher 90-day mortality, which may be related to a greater baseline comorbidity burden and clinical vulnerability. These results support considering thrombectomy in selected patients with prior disability, while highlighting the need for individualized assessment. High-quality prospective studies are still required to confirm these findings.