By Matthew E. Fink, MDLouis and Gertrude Feil Professor and Chair, Department of Neurology, Associate Dean for Clinical Affairs, New York Presbyterian/Weill Cornell Medical College
SOURCE: Albers GW, Lansberg MG, Brown S, et al; AURORA Investigators. Assessment of optimal patient selection for endovascular thrombectomy beyond 6 hours after symptom onset: A pooled analysis of the AURORA database. JAMA Neurol 2021;78:1064-1071.
Since 2015, when multiple clinical trials were published showing the efficacy of endovascular thrombectomy (EVT) for large vessel occlusion within six hours of stroke onset, additional criteria have been developed to identify those patients who will benefit from EVT beyond six hours. Some studies have used a clinical/imaging mismatch to identify appropriate patients and others have used a target perfusion mismatch profile using magnetic resonance imaging or computed tomography perfusion scans. The AURORA investigators collected patient data from six large clinical trials (DAWN, N Engl J Med 2018; DEFUSE3, N Engl J Med 2018; REVASCAT, N Engl J Med 2015; ESCAPE, N Engl J Med 2015; RESILIENT, N Engl J Med 2020; and POSITIVE, J Neurointerv Surg 2021) and performed a meta-analysis to determine if a clinical mismatch or an imaging mismatch protocol was better at predicting good outcomes in patients treated between six hours and 24 hours after the onset of clinical stroke symptoms. Data were pooled from each study, and analysis was performed using mixed effects modeling.
The primary outcome was reduction in disability as measured by the modified Rankin scale score at 90 days. Outcomes were evaluated to determine whether response to treatment differed based on the imaging profile among patients based on the time of last known well. The benefits of treatment were compared between a clinical mismatch group and the target perfusion mismatch group, and then an undetermined profile subgroup. In the combined studies, there were 505 eligible patients, with a mean age of 68.4 years, and 54.9% were women. A total of 266 patients were assigned to the EVT group and 239 patients were assigned to the control group. In the clinical mismatch subgroup and the target perfusion mismatch group, endovascular therapy was associated with a reduction in disability at 90 days compared to the control group.
Benefits were observed in all of the EVT treatment subgroups, with odds ratios for improvement in outcome of 4.95 and 5.01, respectively, with P < 0.001 in both groups. This meta-analysis shows that both criteria, clinical mismatch and target perfusion mismatch, can reliably select patients who will benefit from endovascular therapy between six and 24 hours from onset of stroke symptoms.
