Background: Recent randomized trials demonstrated the efficacy of endovascular therapy (EVT) in managing acute ischemic stroke (AIS), though EVT was initiated <6 hours from time last seen well in nearly all patients, and posterior circulation strokes were excluded. Current data is limited for patients receiving EVT >6 hours, and more so for those with posterior circulation strokes. We aim to assess safety and clinical outcome of EVT in patients presenting >6 hours, with anterior or posterior circulation strokes.
Methods: We conducted a retrospective review of patients with AIS receiving EVT >6 hours between 2012-2015, including those with unknown time of onset and wake-up strokes. Outcomes observed include mRS at ≥90 days, rates of recanalization (TICI 2b-3), sICH and mortality.
Results: A total of 34 patients were identified presenting with AIS and receiving EVT >6 hours, including 25 anterior and 9 posterior circulation strokes. See Table 1 for comparison with published data from recent EVT trials.
Conclusion: Our results are not significantly different from some of the recent trials. MR CLEAN, the only trial that did not employ advanced imaging in patient selection, had similar outcomes. The IV-tPA only groups of recent trials (where data is available) also produced comparable results. It should be noted that the patients in our study all have large vessel occlusions and high NIHSS, are mostly ineligible for tPA, and thus would be expected to have very poor outcomes without treatment. Our data supports the possibility of expanding the EVT window to >6 hours, and with advanced imaging screening, better rates of functional outcome/mortality may still be achieved. DAWN and DEFUSE3 trials currently underway should provide further insight into this subject.