Background: Because endovascular thrombectomy (ET) is appropriate only for patients with acute ischemic stroke (AIS) due to large vessel occlusion (LVO), it’s applicability is limited to a subset of ischemic stroke population. However, as patients with LVO-AIS typically present with severe deficits, larger infarct volumes, and worse final outcomes, ET’s contribution in reducing population-level stroke-related disability and death may be disproportionately higher.
Methods: We conducted a systematic literature review to identify articles reporting, among consecutively encountered acute cerebral ischemia patients: 1) the frequency of LVO; 2) the proportion of disabled or fatal outcomes (mRS 3-6) due to patients with LVO (disability attributable fraction due to LVO); and 3) the proportion of fatal outcomes due to patients with LVO, (mortality attributable fraction due to LVO). We calculated pooled OR estimates and 95% CI using fixed-effects models.
Results: Three studies met search criteria, enrolling 1487 acute cerebral ischemia patients with early vessel imaging. The proportion of all acute cerebral ischemia presentations due to LVO was 48.4% (95% CI 24.4-72.5). Disabled or worse outcomes were more frequent in LVO than non-LVO patients, 62.5% vs 26.8%, OR 4.5 (95% CI 3.6-5.7), p<0.0001. Consequently, the proportion of all disability or worse outcomes from ischemic stroke attributable to LVO patients was 55.2%. Fatal outcomes were also more frequent in LVO than non-LVO patients, 23.0% vs 6.8%, 4.1 (95% CI 2.5-6.6), p<0.0001. Consequently, the proportion of all fatal outcomes from ischemic stroke attributable to LVO patients was 73.1%. Using consensus projections that 24.8% of all AIS are due to LVOs treatable within 8h in a well-developed regional stroke system of care, patients treatable with thrombectomy account for 32.1% of disability or worse outcomes and 37.6% of fatal outcomes among all ischemic strokes.
Conclusion: One-quarter of acute cerebral ischemia patients due to LVO are eligible for ET, but accounts for nearly one-third of ischemia-related disability, and more than one-third of ischemia-related death. Further dissemination of ET therapy may have substantial benefit on population health.