The time from onset to reperfusion is associated with clinical outcomes in acute ischemic stroke due to large vessel occlusion (LVO); nevertheless, the time limit of the continuing procedure remains unclear. We analyzed the relationship between procedure time and clinical outcomes in patients with LVO who underwent endovascular treatment (EVT).
We assessed 1,247 patients who underwent EVT for LVO. Data were obtained from our multicenter registry, and patients were included if data on procedure time were available. Multivariate analysis was performed to assess the impact of procedure time on clinical outcomes using the following parameters: favorable outcome (the modified Rankin score of 0-2 at 90 days), mortality within 90 days, symptomatic intracranial hemorrhage within 72 h after stroke onset, and procedure-related complications.
The rate of favorable outcomes linearly decreased with increasing procedure time, but there was no linear relationship between procedure time and other outcomes. The adjusted odds ratio for 30-minute delay in procedure time was 0.76 (95% confidence interval, 0.68-0.84) for favorable outcome, 1.15 (0.97-1.36) for mortality, 1.08 (0.87-1.33) for symptomatic intracranial hemorrhage, and 0.92 (0.75-1.16) for complications. Significant interactions in the effect of procedure time on favorable outcome were observed between the subgroups stratified by age (≥75 or <75 years). Younger patients had a greater deleterious effect of delayed reperfusion.
Increasing procedure time was associated with less favorable outcomes, but not with the rate of mortality, symptomatic intracerebral hemorrhage, or complications in our cohort.

© 2021 S. Karger AG, Basel.