Microbleeds, cerebral hemorrhage, and functional outcome after endovascular thrombectomy

Objective—To determine whether the presence, number, and distribution of cerebral microbleeds (CMBs) on pretreatment MRI scans are associated with an increased risk of intracerebral hemorrhage (ICH) or poor functional outcome following endovascular thrombectomy (EVT) for acute ischemic stroke (AIS).

Methods—We analyzed prospectively collected data of consecutive patients treated by EVT for AIS, in a comprehensive stroke center where MRI is the first-line pretreatment imaging. Neuroradiologists blinded to clinical data rated CMBs on T2* sequence using a validated scale. We investigated associations of pre-treatment CMB presence, burden (1, 2–4, and ≥5), and presumed pathogenesis with ICH and poor 3-month functional outcome (modified Rankin score >2).

Results—Among 513 patients, 281 (54.8%) had a poor outcome and 89 (17.3%) had ≥1 CMBs. A total of 190 (37%) patients experienced ICH, in which 66 (12.9%) were symptomatic. CMB burden was associated with worse outcome in a univariabl...