Intravenous thrombolysis for acute ischemic stroke with extended time window

Area of Science:

• Neurology
• Cardiovascular Research
• Medical Interventions

Background:

• Intravenous thrombolysis (IVT) is a key treatment for acute ischemic stroke (AIS).
• Established guidelines recommend IVT within 4.5 hours of stroke onset.
• The efficacy and safety of IVT in patients with unclear symptoms or beyond the 4.5-hour window remain less defined.

Purpose of the Study:

• To evaluate the effectiveness and safety of IVT in acute ischemic stroke patients presenting beyond the standard 4.5-hour time window.
• To assess functional outcomes, symptomatic intracerebral hemorrhage (sICH), and mortality rates associated with extended IVT use.

Main Methods:

• A systematic review and meta-analysis of randomized controlled trials (RCTs) comparing IVT with placebo or usual care in AIS patients with onset >4.5 hours.
• Searched major databases including PubMed, Embase, Web of Science, and Cochrane.
• Key outcomes included favorable functional outcome (mRS 0-1), functional independence (mRS 0-2), sICH, and death at 90 days.
• Subgroup analyses were conducted based on age, stroke severity (NIHSS), and time window (4.5-9.0 h vs. >9.0 h).

Main Results:

• Four RCTs involving 848 patients were included, with a low risk of bias.
• IVT significantly improved favorable functional outcomes (45.8% vs. 36.7%) and functional independence (63.8% vs. 55.7%) at 90 days.
• A higher risk of symptomatic intracerebral hemorrhage (sICH) was observed in the IVT group (3.0% vs. 0.5%).
• No significant difference in 90-day mortality was found between IVT and control groups (7.0% vs. 4.1%).

Conclusions:

• IVT administration in acute ischemic stroke patients with an extended time window (beyond 4.5 hours) can enhance functional recovery at 90 days.
• The potential benefits of improved functional outcomes must be weighed against an increased risk of symptomatic intracerebral hemorrhage (sICH).
• Clinical decision-making for these patients requires a careful balance of the potential benefits and harms associated with IVT.