SOURCE: Sarraj A, Hill MD, Hussain MS, et al; SELECT2 Collaborators. Endovascular thrombectomy treatment effect in direct vs transferred patients with large ischemic strokes: A prespecified analysis of the SELECT2 trial. JAMA Neurol 2024;81:327-335.
From the very beginning of the use of intravenous thrombolysis and then from the beginning of the use of endovascular thrombectomy (EVT), it was clear that the faster that the treatment was administered and the quicker the restoration of blood flow, the better the outcome for the patient. Recent clinical trials have investigated which patients who have large ischemic core areas would benefit from EVT. Patients have been evaluated with the use of advanced imaging that calculates diffusion and perfusion, as well as visualized ischemic changes as assessed using the Alberta Stroke Program Early CT Score (ASPECTS) on computed tomography (CT) or magnetic resonance imaging (MRI). The SELECT2 trial was structured to identify which patients with large ischemic strokes would benefit from EVT and analyzed the effect of direct arrival at a thrombectomy-capable center compared to transfer from a primary stroke center. It also was designed to assess the treatment effects for patients who presented with low ASPECTS scores of 3 to 5.
The primary analysis for the study was comparing EVT vs. medical management in patients with large ischemic stroke in adults aged 18 to 85 years. Patients had acute ischemic stroke caused by occlusion of the internal carotid or middle cerebral artery and an ASPECTS score of 3 to 5. The main outcome measure was the modified Rankin Scale score at 90 days. A total of 958 patients were screened, but only 352 were eligible for enrollment. Of those enrolled, 41.2% were female, the median age was 66.5 years, 59.9% of the patients were transfers from primary hospitals, and 40.1% of the patients presented directly to the thrombectomy-capable center.
The median transfer time between hospitals was 178 minutes (range, 136-230) and the median ASPECTS decreased from the referring hospital to an EVT-capable center from a median of 5 to 4. Thrombectomy treatment effect was observed in patients who presented directly to the EVT-capable center as well as those who were transferred. A reduction in ASPECTS during transfer was associated with a worse outcome than for patients who had a stable ASPECTS. EVT treatment effect estimates were worse in patients with transfer times of three hours or more. Both directly presenting as well as transferred patients with large ischemic strokes caused by large vessel occlusion all showed benefit from EVT, but the prolonged transfer times and the decline in the ASPECTS for some patients during transfer was associated a worse 90-day outcome.
This study confirms the importance of speed to treatment regardless of the place of arrival for the patient. Extra effort should be made to facilitate transfer and make it as quick as possible if the patient cannot arrive directly at an EVT-capable center.
