In recent years, the development of intravenous thrombolysis has greatly improved the rate of recanalization and reperfusion in patients with acute ischemic stroke, increasing the proportion of patients with good outcome and reduced mortality. The guideline recommends that patients with ischemic stroke should be treated with intravenous thrombolysis within 4.5 hours. The latest meta-analysis found that ischemic stroke with onset time of 4.5-9 hours with infarction core volume <70ml, ischemic penumbra volume >10ml, and hypoperfusion volume / infarction core volume >1.2 could be benefit from intravenous thrombolysis (the ratio of mRS 0-1 in 3 months, thrombolysis vs non thrombolysis: 35.4% vs 29.5%). Thus, the time window is not an absolute constant indicator. In theory, compared with time window, the physiological window based on the concept of ischemic penumbra is more reasonable.~In 2015, the AHA/ASA guidelines recommended that patients with ischemic stroke with large vessel occlusion should receive endovascular treatment within 6 hours. The DAWN clinical trial has shown that patients with ischemic stroke with large vessel occlusion with onset time of 6-24 hours could be benefit from endovascular treatment after screening by multi-mode imaging (CT perfusion or MR perfusion). As a result, the 2018 AHA/ASA guidelines extended the endovascular treatment window to 24 hours for patients with large vessel occlusion stroke that meet the standard of perfusion. Therefore, we hypothesize that patients with ischemic stroke with onset time of 4.5-24 hours with a definite penumbra may also benefit from intravenous thrombolysis.~Thus, the purpose of this study is to explore whether the patients with ischemic stroke with onset time of 4.5-24 hours can benefit from intravenous thrombolysis if they meet the standard of CT perfusion screening (infarction core volume <70ml, ischemic penumbra volume >10ml, and hypoperfusion volume / infarction core volume >1.2).
The development of intravenous thrombolysis has greatly improved the rate of recanalization and reperfusion in patients with acute ischemic stroke, increasing the proportion of patients with good outcome and reduced mortality. The guideline recommends that patients with ischemic stroke should be treated with intravenous thrombolysis within 4.5 hours. The latest meta-analysis found that ischemic stroke with onset time of 4.5-9 hours with infarction core volume <70ml, ischemic penumbra volume >10ml, and hypoperfusion volume / infarction core volume >1.2 could be benefit from intravenous thrombolysis. The DAWN clinical trial has shown that patients with ischemic stroke with large vessel occlusion with onset time of 6-24 hours could be benefit from endovascular treatment after screening by multi-mode imaging. Therefore, we hypothesize that patients with ischemic stroke with onset time of 4.5-24 hours with a definite penumbra may also benefit from intravenous thrombolysis. The purpose of this study is to explore whether the patients with ischemic stroke with onset time of 4.5-24 hours can benefit from intravenous thrombolysis if they meet the standard of CT perfusion screening.