Intraarterial Thrombolysis Within the First Three Hours After Acute Ischemic Stroke in Selected Patients

Geoffrey A. Donnan MD, FRACP Stephen M. Davis MD, FRACP Section Editors: Several factors determine outcome after an acute ischemic stroke (AIS). These include type of stroke, speed of occlusion, presence of collateral circulation, as well as comorbid medical conditions. Recanalization is important in improving outcome. The results of the large German stroke registry, the MERCI registry, the MULTI-MERCI trial demonstrate a clear correlation of arterial recanalization with improved outcome after AIS.1The only approved therapy for improving outcome of AIS came from the NINDS intravenous thrombolysis trial in 1995 demonstrating an ARR of 11% to 13% after 3 months in achieving a modified Rankin score (mRS) of ≤1 across all groups of patients with AIS.2 Interestingly, patients treated within 90 minutes did better than those treated after 90 minutes within the 3-hour window. This difference was significant and suggests that earlier treatment is associated with a better outcome. However, when analyzed by stroke severity, the magnitude of the benefit declined with increasing NIHSS scores. Patients with NIHSS scores >20 had a ≤6% ARR in achieving mRS <1 at …