Risk factors of hemorrhagic transformation in acute ischaemic stroke: A systematic review and meta-analysis

Background: Hemorrhagic transformation (HT) following reperfusion therapies for acute ischaemic stroke often predicts a poor prognosis. This systematic review and meta-analysis aims to identify risk factors for HT, and how these vary with hyperacute treatment [intravenous thrombolysis (IVT) and endovascular thrombectomy (EVT)].Methods: Electronic databases PubMed and EMBASE were used to search relevant studies. Pooled odds ratio (OR) with 95% confidence interval (CI) were estimated.Results: A total of 120 studies were included. Atrial fibrillation and NIHSS score were common predictors for any intracerebral hemorrhage (ICH) after reperfusion therapies (both IVT and EVT), while a hyperdense artery sign (OR = 2.605, 95% CI 1.212-5.599, I-2 = 0.0%) and number of thrombectomy passes (OR = 1.151, 95% CI 1.041-1.272, I-2 = 54.3%) were predictors of any ICH after IVT and EVT, respectively. Common predictors for symptomatic ICH (sICH) after reperfusion therapies were age and serum glucose level. Atrial fibrillation (OR = 3.867, 95% CI 1.970-7.591, I-2 = 29.1%), NIHSS score (OR = 1.082, 95% CI 1.060-1.105, I-2 = 54.5%) and onset-to-treatment time (OR = 1.003, 95% CI 1.001-1.005, I-2 = 0.0%) were predictors of sICH after IVT. Alberta Stroke Program Early CT score (ASPECTS) (OR = 0.686, 95% CI 0.565-0.833, I-2 =77.6%) and number of thrombectomy passes (OR = 1.374, 95% CI 1.012-1.866, I-2 = 86.4%) were predictors of sICH after EVT.Conclusion: Several predictors of ICH were identified, which varied by treatment type. Studies based on larger and multi-center data sets should be prioritized to confirm the results.

Automated summary

This systematic review and meta-analysis aimed to identify risk factors for hemorrhagic transformation (HT) following reperfusion therapies for acute ischemic stroke, and how these factors vary with different treatments. The results showed that atrial fibrillation and the NIHSS score were common predictors for any intracerebral hemorrhage (ICH) after reperfusion therapies, while a hyperdense artery sign and number of thrombectomy passes were predictors of ICH after intravenous thrombolysis (IVT) and endovascular thrombectomy (EVT), respectively. Age and serum glucose level were common predictors for symptomatic ICH (sICH) after reperfusion therapies.