Impact of workflow times on successful reperfusion after endovascular treatment in the late time window

Background and Purpose Successful and complete reperfusion should be the aim of every endovascular thrombectomy (EVT) procedure. However, the effect of time delays on successful reperfusion in late window stroke patients presenting 6-to-24 h from onset has not been investigated.Materials and Methods We pooled individual patient-level data from seven trials and registries for anterior circulation stroke patients treated with EVT between 6 and 24 h from onset. We explored the impact of delays across multiple interval times, including onset to hospital arrival; hospital arrival to arterial puncture; imaging to arterial puncture; and onset to arterial puncture. Our primary outcome was successful reperfusion, defined as a modified thrombolysis in cerebral infarction (mTICI) score of 2b-3. Logistic regression analyses were performed to assess the association between each of the interval times and successful reperfusion.Results We included 608 patients. The median age was 70 years (IQR 58-79), and 307 (50.5%) were females. Successful reperfusion was achieved in 494 (81.2%) patients. Patients with successful reperfusion had lower NIHSS scores (median 15 [IQR11-19] vs 17 [11-21], p = .02) and significantly shorter hospital arrival to arterial puncture time (90 min [60-150] vs 110 min [84.5-150], p = .01) than unsuccessful reperfusion. The odds of successful reperfusion decreased by 15% for every one-hour delay in arrival-to-puncture time (adjusted odds ratio 0.85, 95% CI: 0.75-0.95). Other workflow times did not impact the rate of successful reperfusion.Conclusion Faster hospital arrival to arterial puncture time is associated with higher odds of successful reperfusion in late window stroke patients.