Intravenous thrombolysis for ischemic stroke with hyperdense middle cerebral artery sign: A meta-analysis

Hyperdense middle cerebral artery sign (HMCAS) on admitting to neuroimaging is reported to have prognostic value for poor outcomes after thrombolysis, while evidence from studies comprising a sufficiently large sample size is limited. To detect prognostic predictors after thrombolysis could help improve therapeutic clinical strategies for acute ischemic stroke. We included prospective and retrospective studies of stroke patients that were treated with intravenous thrombolysis, in which functional outcomes (ie, a modified Rankin scale [mRS]) and systematic intracranial hemorrhage (sICH) were assessed in relation to HMCAS during pretreatment head CT. Random-effects models were used to calculate pooled risk ratios (RR) of poor outcomes and sICH for HMCAS patients as compared to patients without HMCAS. Eleven studies permitted identification of 11 818 patients. The risk of poor outcome at 3 months in the HMCAS-positive group was 1.56-fold the negative group (RR, 1.56; 95% CI 1.50-1.62; P < .001). The sICH risk when comparing both groups was found to be non-significant. Sensitivity analysis regarding studies performing thrombolysis within 3 hours also exhibited significant differences in their functional outcomes (RR, 1.56, 95% CI 1.49-1.62; P < .001) in patients with HMCAS as compared to non-HMCAS patients, although this was true for sICH risk. The presence of HMCAS on pretreatment CT predicts a poor outcome at 3 months after intravenous thrombolysis, while its relationship with the incidence of sICH was found to have no statistic value. Our study implies that more aggressive treatment should be considered for HMCAS patients.