Optimizing Patient Selection for Endovascular Treatment in Acute Ischemic Stroke (SELECT): A Prospective, Multicenter Cohort Study of Imaging Selection

Abstract

Objective The primary imaging modalities used to select patients for endovascular thrombectomy (EVT) are noncontrast computed tomography (CT) and CT perfusion (CTP). However, their relative utility is uncertain. We prospectively assessed CT and CTP concordance/discordance and correlated the imaging profiles on both with EVT treatment decisions and clinical outcomes. Methods A phase 2, multicenter, prospective cohort study of large‐vessel occlusions presented up to 24 hours from last known well was conducted. Patients received a unified prespecified imaging evaluation (CT, CT angiography, and CTP with Rapid Processing of Perfusion and Diffusion software mismatch determination). The treatment decision, EVT versus medical management, was nonrandomized and at the treating physicians’ discretion. An independent, blinded, neuroimaging core laboratory adjudicated favorable profiles based on predefined criteria (CT:Alberta Stroke Program Early CT Score ≥ 6, CTP:regional cerebral blood flow (<30%) < 70ml with mismatch ratio ≥ 1.2 and mismatch volume ≥ 10ml). Results Of 4,722 patients screened from January 2016 to February 2018, 361 patients were included. Two hundred eighty‐five (79%) received EVT, of whom 87.0% had favorable CTs, 91% favorable CTPs, 81% both favorable profiles, 16% discordant, and 3% both unfavorable. Favorable profiles on the 2 modalities correlated similarly with 90‐day functional independence rates (favorable CT = 56% vs favorable CTP = 57%, adjusted odds ratio [aOR] = 1.91, 95% confidence interval [CI] = 0.40–9.01, p = 0.41). Having a favorable profile on both modalities significantly increased the odds of receiving thrombectomy as compared to discordant profiles (aOR = 3.97, 95% CI = 1.97–8.01, p < 0.001). Fifty‐eight percent of the patients with favorable profiles on both modalities achieved functional independence as compared to 38% in discordant profiles and 0% when both were unfavorable (p < 0.001 for trend). In favorable CT/unfavorable CTP profiles, EVT was associated with high symptomatic intracranial hemorrhage (sICH) (24%) and mortality (53%) rates. Interpretation Patients with favorable imaging profiles on both modalities had higher odds of receiving EVT and high functional independence rates. Patients with discordant profiles achieved reasonable functional independence rates, but those with an unfavorable CTP had higher adverse outcomes. Ann Neurol 2020;87:419–433

Quantified ischemic core’s radiological hypodensity and risk of parenchymal hematoma in > 4.5 h-window stroke thrombectomy

“…The second HERMES metanalysis provided preliminary data suggesting that carefully selected patients with large cores (ASPECTS 3-5) may have more favorable functional outcomes despite an increased risk of ICH 14 . In line with these results, the SELECT trial 15 showed that in patients with unfavorable CT/favorable CTP, thrombectomy was associated with a reduction in mortality compared to medical management with similar safety outcomes regarding sICH. There are clinical trials underway to clarify this issue, in which after our results, the darkness of the ischemic core could be assessed together with core volume to evaluate its relative contribution to bleeding risk in this particular subset of EVT patients.…”

Acute reperfusion therapies for acute ischemic stroke patients with unknown time of symptom onset or in extended time windows: an individualized approach

“…Patients with favorable CT but unfavorable CT perfusion profiles had lower functional independence and high rates of symptomatic ICH, neurological worsening, and mortality. 137 A recent commentary of the SELECT2 Investigators meticulously delineates the uncertainty behind simple neuroimaging for patients with larger cores and is relevant for the debate for extended time windows. 138 Using the Alberta Stroke Program Early CT score (ASPECTS) to estimate established infarction is a strategy appearing simple but in practice is prone to errors; even after ASPECTS training, one in three readings from neuroradiologists resulted in misclassification (ASPECTS 0–2 versus 3–5 versus 6–8) in 20 illustrative cases.…”

Endovascular thrombectomy in patients with large core ischemic stroke: a cost-effectiveness analysis from the SELECT study

“…"The Optimizing Patient Selection for Endovascular Treatment in Acute Ischemic Stroke (SELECT): a Prospective Multicenter Cohort Study of Imaging Selection" 22 enrolled patients with stroke attributable to large-vessel occlusion who were treated with endovascular thrombectomy plus medical management or medical management alone, based on CT or CTP findings, up to 24 hours from the point that they were last known to be well at 9 comprehensive stroke centers across the United States. The decision to proceed with EVT vs medical management alone was made at the discretion of the local investigators in a nonrandomized fashion.…”

“…We sought to assess EVT cost-effectiveness by performing a cost-effectiveness analysis for EVT as compared to medical management only (MM) using outcomes in patients with large ischemic core infarcts on CT (ASPECTS <6), CTP (rCBF <30% volume ≥ 50 cm 3 ) or both from the SELECT study, a prospective, multicenter cohort study of imaging selection 22 .…”