Predictors of Symptomatic Intracranial Hemorrhage after Endovascular Thrombectomy in Acute Ischemic Stroke: A Systematic Review and Meta-Analysis

Introduction: This meta-analysis assessed the predictors of symptomatic intracranial hemorrhage (sICH) after endovascular thrombectomy (EVT) for patients with acute ischemic stroke. Methods: PubMed, Embase, the Cochrane Central Register of Controlled Trials, and Web of Science were searched for studies published from inception to February 16, 2021. We included studies that evaluated the predictors of sICH after EVT. The random-effect model or fixed-effect model was used to pool the estimates according to the heterogeneity. Results: A total of 25 cohort studies, involving 15,324 patients, were included in this meta-analysis. The total incidence of sICH was 6.72 percent. Age (MD = 2.57, 95% CI: 1.53-3.61; p < 0.00001), higher initial NIHSS score (MD = 1.71, 95% CI: 1.35-2.08, p < 0.00001), higher initial systolic blood pressure (MD = 7.40, 95% CI: 5.11-9.69, p < 0.00001), diabetes mellitus (OR = 1.36, 95% CI: 1.10-1.69, p = 0.005), poor collaterals (OR = 3.26, 95% CI: 2.35-4.51; p < 0.0001), internal carotid artery occlusion (OR = 1.55, 95% CI: 1.26-1.90; p < 0.0001), longer procedure time (MD = 18.92, 95% CI: 11.49-26.35; p < 0.0001), and passes of retriever > 3 (OR = 3.39, 95% CI: 2.45-4.71; p < 0.0001) were predictors of sICH, while modified thrombolysis in cerebral infarction score >= 2b (OR = 0.61, 95% CI: 0.46-0.79; p = 0.0002) was associated with a decreased risk of sICH. There were no significant differences in the female gender, initial serum glucose, initial ASPECT score, atrial fibrillation, oral anticoagulants, antiplatelet therapy, intravenous thrombolysis, general anesthesia, neutrophil-to-lymphocyte ratio, and emergent stenting. Conclusions: This study identified many predictors of sICH. Some of the results lack robust evidence given the limitations of the study. Therefore, larger cohort studies are needed to confirm these predictors.