Although the ischemic core is traditionally considered irreversibly injured, emerging evidence suggests it may be reversible on follow-up imaging, particularly after endovascular thrombectomy (EVT). We conducted a systematic review and meta-analysis to assess the prevalence, predictors, and outcomes of ischemic core reversal in acute ischemic stroke (AIS). We searched Medline, Embase, Scopus, and Web of Science through December 2024 for studies reporting core reversal after EVT. Fourteen studies (3640 patients) with baseline and follow-up imaging were included. A random-effects model was used to pool prevalence, associated factors, and outcomes. Core reversal occurred in 17.5% (95% CI: 11.9%–25.1%), more often in MR-based (19.9%) than CT-based (15.9%) studies, and at 24–48 h (19.1%) versus 48–168 h (12.3%). Predictors included shorter onset-to-baseline imaging time (median difference 90 min), IV thrombolysis (OR 1.41, 95% CI: 1.09–1.83), and successful recanalization (TICI 2B–3: OR 2.89, 95% CI: 1.65–5.06). Diabetes was associated with lower odds (OR 0.64, 95% CI: 0.47–0.86). Reversal correlated with better functional outcomes (mRS 0–2: OR 2.11, 95% CI: 1.55–2.86). Ischemic core reversal indicates that early imaging may overestimate infarct volume.
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