Reperfusion therapies for ischemic stroke in dementia and cognitive impairment: A systematic review and meta-analysis

Background: Endovascular thrombectomy (EVT) and intravenous thrombolysis (IVT) have an unclear benefit in those with pre-stroke dementia or cognitive impairment, as these patients were often excluded from landmark stroke trials. We performed a systematic review and meta-analysis to assess the outcomes of IVT and EVT in these populations. Aims: Our systematic review, conforming to the Meta-Analysis of Observational Studies in Epidemiology guidelines, investigated studies on acute ischemic stroke patients with pre-stroke dementia or cognitive impairment treated with IVT or EVT. Primary outcome was favorable 90-day outcome (mRS 0–2). Secondary outcomes included 90-day mortality, symptomatic intracranial hemorrhage (SICH), and radiographic intracranial hemorrhage (ICH). Summary of review: Nine articles were identified, with five observational studies of IVT use in patients with (n = 1078) and without dementia (n = 2805) being selected for the meta-analysis. There were no significant differences in favorable outcome (adjusted OR: 0.61, 95% CI 0.24–1.59), mortality (unadjusted OR: 1.19, 95% CI 0.86–1.64), ICH (unadjusted OR: 1.32, 95% CI 0.79–2.19), and symptomatic ICH (unadjusted OR: 0.94, 95% CI 0.70–1.25) for patients undergoing IVT with pre-stroke dementia versus those without. One EVT study (n = 615 with dementia vs n = 9600 without) found no significant differences in outcomes apart from an increased odds of ICH for those with pre-existing dementia (adjusted OR: 1.57, 95% CI 1.03–2.40). A pooled analysis of three IVT studies showed no significant association of cognitive impairment (n = 93 vs n = 211 without) with all assessed outcomes, whereas a study of EVT found that pre-stroke cognitive impairment was associated with poor 90-day outcomes (mRS 3–6). Conclusion: These results suggest no substantial safety issues in the use of IVT or EVT for patients with pre-existing dementia or cognitive impairment compared to those without. However, the efficacy of these therapies in this demographic remains uncertain. Further rigorous studies that include a more nuanced outcome measurement approach are warranted. Registration: URL: https://www.crd.york.ac.uk/PROSPERO/; Unique identifier: CRD42021240499.