Comparing the Efficacy and Safety of Intravenous Thrombolytics in Ischemic Stroke Beyond the 4.5-Hour Time Window: A Systematic Review and Meta-analysis of Randomized Controlled Trials
Zain ul Abideen1, Hassan Waseem2, Dua Ghori3, Faizan Shahzad4, Shamama Kaleem3, Misha Ahmed3, Muhammad Ansari5, Muhammad Ansari6, Rowaid Ahmad6, Justin Chen7, Jamir Pitton Rissardo8, Ana Leticia Fornari Caprara8, Vishnu Byroju9, Brandon Lucke-Wold10, Adam Dmytriw11
1King Edward Medical University, 2Allama Iqbal Medical College, 3Dow Medical College, 4Rawalpindi Medical University, 5Jinnah Sindh Medical University, 6UTMB, 7Texas A&M College of Medicine, 8Cooper University Hospital, 9Cooper University Healthcare, 10University of Florida, 11Massachusetts General Hospital
Objective:

This meta-analysis aims to evaluate the efficacy and safety of intravenous thrombolytics (IVTs) in ischemic stroke beyond the 4.5-hour window.

Background:

Stroke significantly affects global health, and IVTs like tenecteplase and alteplase are highly time-dependent. Although they show potential beyond 4.5 hours, the evidence remains inconclusive.

Design/Methods:

PubMed, Cochrane Central, and ScienceDirect were searched through August 2025. The risk ratios (RRs) were pooled with 95% confidence intervals under the random effects model using Review Manager version 5.4.1. The quality assessment was done using the Cochrane Risk of Bias (RoB) 2.0 tool. An excellent functional outcome is defined as a modified Rankin Scale (mRS) score of 0-1. A good functional outcome is defined as an mRS of 0-2.   

Results:

Thirteen randomized controlled trials involving a total of 3,602 patients were analyzed. Compared to the control group, IVT significantly improved the rates of excellent (RR= 1.22; 95%CI: [1.13, 1.31];p <0.00001; I2 = 0%) and good (RR= 1.11; 95%CI: [1.06, 1.18];p <0.0001; I2 = 0%) functional outcomes. However, the risk of symptomatic (RR= 2.28; 95%CI:[1.35, 3.85];p = 0.002; I2 = 0%) and any (RR= 1.22; 95%CI:[1.01, 1.46];p = 0.04; I2 = 13%) intracranial hemorrhage (ICH) was also higher with IVT; mortality rates, however, showed no significant difference (RR= 1.10; 95%CI:[0.89, 1.36];p = 0.35). Tenecteplase at 0.25 mg/kg did not improve functional outcomes or increase the risk of ICH. Similarly, low-dose 0.60 mg/kg alteplase did not significantly enhance functional outcomes or raise the risk of ICH, while alteplase at 0.90 mg/kg showed results consistent with the overall IVT group.

Conclusions:

IVT significantly improved the functional outcomes (excellent and good) but increased the risk of ICH (symptomatic and any) with comparable mortality, primarily in the alteplase 0.90 mg/kg subgroup. However, the 0.25 mg/kg tenecteplase and 0.60 mg/kg low-dose alteplase showed no increase in functional or hemorrhagic outcomes.

10.1212/WNL.0000000000212969
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