Extending the Treatment Window for Intravenous Thrombolysis in Acute Ischemic Stroke

BACKGROUND AND OBJECTIVES: Intravenous thrombolysis (IVT) is the standard treatment for acute ischemic stroke within 4.5 hours of onset. However, imaging-based selection may extend the treatment window. This systematic review and meta-analysis evaluated the efficacy and safety of IVT administered beyond 4.5 hours after stroke onset or last known well (LKW) in patients selected based on imaging findings. METHODS: A comprehensive search of PubMed, Scopus, and Cochrane Library was performed to identify randomized controlled trials comparing IVT with alteplase or tenecteplase (TNK) administered >4.5 hours after stroke onset/LKW vs standard care. Primary outcomes were 3-month excellent (modified Rankin Scale [mRS] 0-1) functional outcome and symptomatic intracranial hemorrhage (sICH). Secondary outcomes included good (mRS 0-2) functional outcome, recanalization, and 3-month mortality. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using random-effects models. Subgroup analysis assessed differences between alteplase and TNK. RESULTS: = 0.11). DISCUSSION: Among patients selected based on imaging, 4.5-24 hours after stroke onset/LKW, IVT improves outcomes despite an increased risk of sICH. TNK showed similar efficacy to alteplase, with a possible lower risk of sICH; however, direct comparisons in future trials are needed.