Prognostic and etiological implications of the susceptibility vessel sign in acute ischemic stroke: An updated meta-analysis

Background The susceptibility vessel sign (SVS) on MRI has been linked to functional outcomes and reperfusion success after endovascular treatment (EVT), suggesting its potential as a prognostic marker. This updated systematic review and meta-analysis aimed to evaluate the prognostic and etiological significance of SVS in acute ischemic stroke (AIS). Methods We conducted a systematic search of PubMed, Embase, and Cochrane in May 2025. Eligible studies included post-hoc analyses of randomized controlled trials (RCTs) and observational studies of AIS patients treated with EVT and/or intravenous thrombolysis (IVT). Pooled risk ratios (RRs) with 95% confidence intervals (CIs) were calculated using a random-effects model. Primary outcome was successful reperfusion (mTICI 2b-3). Secondary outcomes included functional independence (modified Rankin Scale [mRS] score 0–2), mortality, stroke etiology, and time metrics. Results Eighteen studies ( n = 2602) were included. Overall, SVS was not associated with higher reperfusion rates (12 studies; n = 2083; RR: 1.01; 95% CI: 0.93–1.10; p = .832; I 2 = 56.0%), except in the SWI subgroup (2 studies; RR: 1.17; 95% CI: 1.02–1.34; p = .022; I 2 = 0.0%). SVS + was linked to lower 90-day mortality in anterior circulation strokes (3 studies; n = 865; RR: 0.52; 95% CI: 0.36–0.74; p < .001; I 2 = 0%), improved 90-day functional independence in Western populations (7 studies; n = 1481; RR: 1.22; 95% CI: 1.01–1.47, p = .039; I 2 = 37.7%), and in cardioembolic stroke etiology using GRE (9 studies; n = 1058; RR: 1.29; 95% CI: 1.05–1.57; p = .014; I 2 = 36.3%). The mean time from onset to treatment was 238.19 minutes ± 147.5. Conclusions Although SVS + did not predict reperfusion, it was associated with better functional outcomes in Western populations, particularly in cardioembolic stroke, and lower mortality, thereby reinforcing its prognostic value. MRI protocols did not delay treatment, but high heterogeneity limits certainty, highlighting the need for prospective studies.