Intravenous Thrombolysis Administration 3-4.5 h After Acute Ischemic Stroke: A Retrospective, Multicenter Study

Area of Science:

• Neurology
• Cardiovascular Medicine
• Pharmacology

Background:

• Intravenous recombinant tissue plasminogen activator (rt-PA) is approved for acute ischemic stroke (AIS) within 3 hours.
• The FDA has not approved rt-PA for the expanded 3-4.5 hour time window.
• This study evaluates rt-PA effectiveness and safety in AIS patients treated between 3-4.5 hours.

Purpose of the Study:

• To investigate the effectiveness of rt-PA in AIS patients treated within 3-4.5 hours.
• To assess the safety profile of rt-PA in this patient group.
• To compare outcomes with a matched control group not receiving thrombolysis.

Main Methods:

• Retrospective, matched cohort study using stroke registries from 16 hospitals (2008-2017).
• Treatment group: AIS patients receiving rt-PA at 3-4.5 hours.
• Control group: Age- and sex-matched AIS patients without contraindications, not receiving thrombolysis.

Main Results:

• 34.0% of rt-PA treated patients achieved modified Rankin Scale (mRS) 0-1 at 90 days, versus 22.7% in the control group (OR 1.75, P=0.001).
• No significant differences in symptomatic intracerebral hemorrhage (ICH), early neurological deterioration, or 3-month mortality.
• Standard vs. low dose rt-PA showed no significant difference in mRS or ICH.

Conclusions:

• Results support rt-PA use in AIS patients 3-4.5 hours after onset.
• rt-PA is an effective and tolerable treatment for functional recovery in this extended time window.
• Further supports expanded rt-PA indications for AIS.