Association of hyperdense middle cerebral artery sign with clinical outcome in patients treated with tissue plasminogen activator

Background and Purpose-The hyperdense middle cerebral artery sign (HMCAS) i s a marker of thrombus in the middle cerebral artery. The aim of our study was to find out the frequency of the HMCAS, its association with initial ne urological severity and early parenchymal ischemic changes on CT, its relev ance to clinical outcome, and the efficacy of intravenous recombinant tissu e plasminogen activator (rtPA) in patients with the HMCAS, Methods-Secondary analysis of the data from 620 patients who received eithe r rtPA or placebo in the European Cooperative Acute Stroke Study I(ECASS I) , a double-blind, randomized, multicenter trial. The baseline CT scans were obtained within 6 hours from the onset of symptoms. Functional and neurolo gical outcomes were assessed using the modified Rankin Scale and the Scandi navian Stroke Scale at day 90. Results-We found an HMCAS in 107 patients( 17.7%). The initial neurological deficit was more severe in patients with the HMCAS than in those lacking t his sign (P<0.0001). Early cerebral edema and mass effect were also more co mmon in patients with the HMCAS (P<0.0001). The HMCAS was related to the ri sk of poor functional outcome (grade of 3 to 6 on the modified Rankin Scale ) on univariate analysis: 90 patients (84%) with the HMCAS and 310 patients (62%) lacking this sign were dependent or dead at day 90 (P<0.0001). Howev er, this association was no longer significant in a logistic model accounti ng for the effect of age, sex, treatment with rtPA, initial severity of neu rological deficit and early parenchymal ischemic changes on CT. Patients wi th the HMCAS who were given rtPA had better neurological recovery than thos e who received placebo (P=0.0297). Conclusions-The HMCAS is associated with severe brain ischemia and poor fun ctional outcome. However, it has no significant independent prognostic valu e when accounting for the effect of initial severity of neurological defici t and of early parenchymal ischemic changes on CT. Patients with the HMCAS may benefit from intravenous rtPA.