Association between time to treatment and clinical outcomes in endovascular thrombectomy beyond 6 hours without advanced imaging selection

Abstract

BackgroundThe effectiveness and safety of endovascular thrombectomy (EVT) in the late window (6–24 hours) for acute ischemic stroke (AIS) patients selected without advanced imaging is undetermined. We aimed to assess clinical outcomes and the relationship with time-to-EVT treatment beyond 6 hours of stroke onset without advanced neuroimaging.MethodsPatients who underwent EVT selected with non-contrast CT/CT angiography (without CT perfusion or MR imaging), between October 2015 and March 2020, were included from a national stroke registry. Functional and safety outcomes were assessed in both early (<6 hours) and late windows with time analyzed as a continuous variable.ResultsAmong 3278 patients, 2610 (79.6%) and 668 (20.4%) patients were included in the early and late windows, respectively. In the late window, for every hour delay, there was no significant association with shift towards poorer functional outcome (modified Rankin Scale (mRS)) at discharge (adjusted common OR 0.98, 95% CI 0.94 to 1.01, p=0.27) or change in predicted functional independence (mRS ≤2) (24.5% to 23.3% from 6 to 24 hours; aOR 0.99, 95% CI0.94 to 1.04, p=0.85). In contrast, predicted functional independence was time sensitive in the early window: 5.2% reduction per-hour delay (49.4% to 23.5% from 1 to 6 hours, p=0.0001). There were similar rates of symptomatic intracranial hemorrhage (sICH) (3.4% vs 4.6%, p=0.54) and in-hospital mortality (12.9% vs 14.6%, p=0.33) in the early and late windows, respectively, without a significant association with time.ConclusionIn this real-world study, there was minimal change in functional disability, sICH and in-hospital mortality within and across the late window. While confirmatory randomized trials are needed, these findings suggest that EVT remains feasible and safe when performed in AIS patients selected without advanced neuroimaging between 6–24 hours from stroke onset.

Direct to angiosuite strategy versus standard workflow triage for endovascular therapy: systematic review and meta-analysis

“…Finally, the latest generation of software has been tested to quantitatively determine ASPECTS and infarct volumes 55 56. However, based on recent publications which showed that more simplified methods to triage late window patients for EVT might be as accurate as advanced imaging,57–59 it is reasonable to suggest that incorporating FPCT not only optimizes patient selection in the early window but may also expand DTAS strategy to late window patients at centers where FP technology is available.…”

Late Window Imaging Selection for Endovascular Therapy of Large Vessel Occlusion Stroke: An International Survey

“…19 Similar results were found in other studies. 36 These data indicate that NCCT might be a reasonable imaging alternative for patient selection in the extended time window challenging the current guidelines stating that advanced imaging is required. The lower cost of plain CT (compared with CTP or MRI) and conservation of contrast for parenchymal selection may be other advantages to consider particularly for low-and middle-income countries, and in the setting of finite resources.…”

Common Data Elements Reported in Mechanical Thrombectomy for Acute Ischemic Stroke: A Systematic Review of Active Clinical Trials

“…The only data element prevalent in all studies was LWK. However, it is not an indicator of homogeneity: while the studies required the LWK to be known for initial consideration, the actual recruitment was based on different cut-offs ranging from ≤4.5 to 24 h. Although several studies have shown good safety and efficacy trials for EVT up to 24 h of LWK, the functional outcomes are still variable among different intervals, limiting any future efforts to pool them together [ 2 , 3 , 4 , 5 ]. The encountered heterogeneity of ASPECTS categorization has been observed in large core trials, with valid concerns being raised about the inconsistency of ASPECTS grading, its ability to define “large core,” and the reliability of capturing targeted patients [ 20 ].…”

“…Over the past years, several randomized clinical trials have assessed and validated the efficacy and safety of endovascular thrombectomy (EVT) in acute stroke patients, mainly the anterior circulation occlusion [ 2 , 3 , 4 , 5 ]. As a result, this evolving treatment modality is now considered the standard of care for acute ischemic stroke patients (AIS), with a concrete level 1 class A level of evidence [ 6 , 7 ].…”