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.