Endovascular thrombectomy in late-window stroke: Do perfusion imaging and large infarcts really matter? A systematic review and meta-analysis of 10 randomized clinical trials

Abstract

Background

Several randomized trials have evaluated the benefits of endovascular thrombectomy (EVT) for anterior circulation large vessel occlusion strokes presenting beyond 6 hours of the last known well (LKW). We aimed to synthesize the results from these trials to provide high-level evidence regarding EVT treatment for patients presenting in the late window.

Methods

A systematic search was conducted through four electronic databases, with no language restriction. Binary outcomes were analyzed using the risk ratio (RR) and 95 % confidence interval (CI), while continuous outcomes were analyzed using the standardized mean difference (SMD) and 95 % CI.

Results

Out of 2824 patients from 10 trials comparing EVT plus BMT and BMT alone among patients with AIS who presented beyond 6 hours of LKW, 1871 patients (n = 981 EVT, n = 890 BMT) were included in the analysis. The results showed benefits toward the EVT than BMT alone in Modified Rankin Scale (mRS) 0–1 (RR= 1.84, 95 %CI= 1.4– 2.4), mRS 0–2 (RR= 2.3, 95 %CI= 1.5– 2.1), and mRS 0–3 (RR= 1.64, 95 %CI= 1.3– 1.63) at three months. No significant difference between EVT and BMT alone groups was found when analyzing either 90-day mortality or symptomatic intracranial hemorrhage. Subgroup analysis showed that there was no significant difference between patients with large core stroke and patients with non-large core stroke in 90-day mRS 0–2 (RR= 3.6 vs 2.37, P-value=0.26). Findings did not show significant difference between perfusion vs non-perfusion imaging modalities in 90-day mRS 0–2 and mortality.

Conclusion

These findings strengthen the previous evidence for the benefits of EVT over medical treatment in managing patients with stroke, even with large ischemic regions in the late time window.