[Intravenous thrombolysis for acute ischemic stroke: past, present and future]

The efficacy of intravenous thrombolysis using alteplase, a recombinant tissue plasminogen activator (IV t-PA) within a 4.5-hour time window for acute ischemic stroke patients has been well established. However, a tight time window allows a minority of stroke patients to receive IV t-PA, and low recanalization rates of large intracranial artery occlusions limit the efficacy of IV t-PA. To overcome the limitations of IV t-PA, clinical trials regarding IV t-PA based on DWI-PWI mismatch or DWI-FLAIR mismatch, next-generation agents of t-PA, dose modification of alteplase, sonothrombolysis, and so on are going on worldwide. Shortening of the time of door to treatment (needle or femoral puncture) plays a very important role to enhance the efficacy of acute reperfusion therapy including IV t-PA and acute stroke endovascular therapy, and as a consequence, it could contribute to improve the entire stroke outcomes due to an increase of acute reperfusion therapy-eligible patients.