Stroke Thrombectomy for Large Infarcts with Limited Penumbra: Systematic Review and Meta-Analysis of Randomized Trials

BACKGROUND: Recent randomized trials have suggested that endovascular thrombectomy (EVT) is superior to medical management (MM) for stroke patients with large infarcts. However, whether or how perfusion metrics should be used to guide optimal patient selection for treatment is unknown.

PURPOSE: To synthesize trial results to provide more definitive guidance on the role of EVT for stroke patients with large infarcts based on perfusion metrics.

DATA SOURCES: MEDLINE database from inception up to July 8, 2024. Randomized controlled trials that report the efficacy and safety of EVT for patients with large infarcts (defined by either infarct core volume greater than 50cc or Alberta Stroke Program Early CT Score [ASPECTS] less than 6) stratified by mismatch profile were included.

STUDY SELECTION: Five trials were identified – SELECT2 and ANGEL-ASPECT.

DATA ANALYSIS: The primary outcome was odds of acceptable outcomes (90-day modified Rankin scale [mRS] 0 to 3). Secondary outcome was 90-day mRS 5 or 6. Patients where then subdivided into those with mismatch ratio 1.2–1.8 or penumbra volume 10–15cc (intermediate mismatch) and those with mismatch ratio <1.2 or volume <10cc (low mismatch).

DATA SYNTHESIS: A total of 140 intermediate mismatch (75 EVT and 65 MM) and 60 low mismatch patients (23 EVT and 37 MM) were identified. EVT was significantly associated with higher odds of mRS 0–3 for intermediate mismatch (OR 2.77 [95% CI 1.11–6.89], P = .028), but not low mismatch (OR 1.47 [95% CI 0.44–4.94], P = .54). Similarly, in terms of 90-day poor outcomes (mRS 5–6), EVT for intermediate mismatch patients was significantly associated with lower odds (OR 0.49 [95% CI 0.24 to 0.99], P = .046), while EVT for the low mismatch cohort was not (OR 0.66 [95% CI 0.22 to 1.96], P = .45). There was no significant inter-study heterogeneity observed across study estimates.

CONCLUSIONS: For stroke patients with large infarcts, EVT was beneficial for patients with perfusion mismatch ratio and volume of at least 1.2 and 10cc, but not for those with mismatch ratio <1.2 or volume <10cc.