Target mismatch criteria in acute ischemic stroke patients with distal-medium vessel occlusion

Introduction: The efficacy of endovascular treatment (EVT) in ischemic stroke patients with distal-medium vessel occlusion (DMVO) remains unclear. We evaluated whether CT-perfusion target mismatch criteria (TMC) could predict functional independence in patients with M2 non- or codominant middle cerebral artery DMVO. Materials and methods: This retrospective study analyzed consecutive patients with M2 DMVO receiving EVT and imaged with multimodal CT study protocol within 24 h from onset. A receiver operating characteristic curve analysis was used to identify the infarct core volume cutoff to predict functional independence (modified Rankin Scale 0–2 at 3-months). This parameter was subsequently considered as part of TMC together with penumbra volume ⩾ 10 mL and mismatch ratio ⩾1.2. The association between TMC and functional independence was tested with logistic regression. Results: A total of 115 patients with M2 were included. Infarct core volume had good discriminative ability for functional independence (AUC 0.75; 95%CI 0.64–0.84) and the best cut-off value was ⩽30 mL (77% sensitivity, 61% specificity, 69% positive predictive value, 70% negative predictive value). TMC were independently associated with functional independence (OR [odds ratio] = 6.50, 95%CI = 2.37–17.77, p < 0.001), excellent outcome (modified Rankin scale 0–1 at 3-months, OR = 3.28, 95%CI = 1.30–8.31, p = 0.012) and final infarct volume (B = −35.52, p = 0.004). After including interaction terms, a significant treatment effect on functional independence was observed between successful recanalization and TMC (OR = 3.82, 95%CI = 1.64–8.89, p = 0.002). Discussion and conclusion: In patients with M2 non- or codominant DMVO receiving EVT, TMC identified as core volume ⩽30 mL, penumbra volume ⩾ 10 mL, and mismatch ratio ⩾ 1.2, were associated with better functional outcome. Our findings suggest that functional independence after EVT was not directly related to successful recanalization, which is indeed effective only in patients with a favorable baseline imaging profile, including a small infarct core size, and in the presence of small penumbra volumes.