Risk of Hemorrhagic Transformation and Its Subtypes After Endovascular Therapy vs Medical Management in Large Core Ischemic Stroke: A Systematic Review and Meta Analysis of Randomized Clinical Trials.
Abstract
Background
Endovascular therapy (EVT) improves outcomes in selected patients with large-core acute ischemic stroke (AIS), but concerns remain regarding hemorrhagic transformation (HT). We evaluated the risk of intracranial hemorrhage (ICH) and its subtypes following EVT versus medical management (MM).
Methods
PubMed, Embase, and Scopus were searched through February 2026. Randomized clinical trials (RCTs) enrolling adults with large-core AIS (ASPECTS ≤5 or ischemic core volume ≥70 mL) were included. Risk ratios (RRs) were pooled using random-effects models.
Results
Six RCTs (n=1,887) and five post hoc publications from same trials were included. EVT increased the risk of any ICH compared with MM (RR=1.80, 95% CI: 1.40-2.30; P<0.001). Risks of HI2 (RR=2.23), PH1 (RR=2.42), and subarachnoid hemorrhage (RR=2.21) were significantly higher, whereas PH2 and intraventricular hemorrhage were not. Symptomatic ICH occurred more frequently after EVT (5.0% vs. 3.1%; P=0.02), but this finding was not robust to sensitivity analyses. In ASPECTS 0-2 neither any ICH nor symptomatic ICH was significantly increased; however, limited sample size and influential studies precluded excluding clinically meaningful risk.
Conclusion
EVT increased radiographic hemorrhage, primarily HI2 and PH1, without a significant increase in PH2. The modest increase in symptomatic ICH was sensitive to the contributing trial and definition.