Association of Lesion Topography with Functional Outcomes in Acute Ischemic Stroke Patients Considered for, or Receiving, Reperfusion Therapy: A Meta-Analysis

Abstract

Background: The impact of lesion topography (LT), characterised by the Alberta Stroke Programme Early CT Score (ASPECTS), on outcomes after reperfusion therapy in acute ischemic stroke (AIS) is poorly elucidated. We investigated the prognostic accuracy of ASPECTS-based LT assessment and its association with clinical outcomes in AIS patients considered for reperfusion therapy or receiving intravenous thrombolysis (IVT), endovascular thrombectomy (EVT), or none or both. Methods: Studies were identified from PubMed with additional studies added from Google Scholar. The prevalence of individual ASPECTS regions will also be determined. The association of individual ASPECTS regions with the functional outcome at 90 days will be assessed using random-effects modelling for various cut-offs, such as 6, 7 and 8. The association of continuous ASPECTS with the functional outcome at 90 days will also be undertaken. Forest plots of odds ratios (ORs) will be generated. Results: A total of 25 studies have been included in the final analysis, encompassing 11,404 patients. Pooled estimates indicate that the highest prevalence rates were in cases involving the insula and lentiform nucleus. Subgroup analysis for ASPECTS < 6 (OR 6.10; 95% CI 2.50−14.90; p < 0.0001), ASPECTS < 7 (OR 4.58; 95% CI 1.18−17.86; p < 0.0001) and ASPECTS < 8 (OR 2.26; 95% CI 1.32−3.89; p < 0.0001) revealed a significant association with poor functional outcome at 90 days. Decreasing ASPECTS significantly increased the odds of poor functional outcomes at 90 days (SMD −1.15; 95% CI −1.77−−0.52; p < 0.0001). Conclusions: Our meta-analysis demonstrates that decreasing ASPECTS is significantly associated with poor functional outcomes. Individual ASPECTS regions associated with the highest odds of poor functional outcomes were identified. Future studies on the association of LT and clinical outcomes specific to EVT are required.

Keywords: ASPECTS; cerebrovascular disorders; neuroimaging; reperfusion therapy; stroke; topography.

Figure 1

The PRISMA flowchart showing the studies included in the meta-analysis. Abbreviations: N = number of studies; n = number of patients; mRS: modified Rankin Score; ASPECTS: Alberta Stroke Programme Early CT Score.

Figure 2

Proportion of infarcts in specific regions [15,17,18,20,27,28].

Figure 3

Forest plot of estimated effect for the association of: (A) ASPECTS < 6 [27,30,36,37,38], (B) ASPECTS < 7 [24,25,26,34,38], (C) ASPECTS < 8 [6,23,29,31,38] and (D) continuous ASPECTS [16,19,22,33,35,38] with functional outcome at 90 days (mRS 90 days) in acute ischaemic stroke patients receiving, or considered for, reperfusion therapy. Note: IVT ± EVT: All patients received IVT, with or without EVT. EVT ± IVT: All patients received EVT, with or without IVT. No RT: All patients were considered for reperfusion therapy but were not eligible (received neither IVT nor EVT). No RT ± EVT: All patients were not eligible for IVT, but some received EVT. Abbreviations: IVT: intravenous thrombolysis; EVT: endovascular thrombectomy; RT: reperfusion therapy; ASPECTS: Alberta Stroke Programme Early CT Score.

Figure 4

The summary receiver operating characteristics curves for the association of (A) ASPECTS < 6, (B) ASPECTS < 7 and (C) ASPECTS < 8 with functional outcomes at 90 days (mRS 90 days) in acute ischaemic stroke patients considered for, or receiving, reperfusion therapy. Note: the summary receiver operating characteristics curves for the association of continuous ASPECTS with functional outcomes at 90 days (mRS 90 days) in acute ischemic stroke patients receiving reperfusion therapy cannot be generated. Abbreviations: ASPECTS: Alberta Stroke Programme Early CT Score; mRS: modified Rankin Score.