Refining the Tmax malignant profile in large ischemic core patients receiving endovascular treatment

Background and purpose: A significant proportion of patients with large ischemic core volume (LICV) have poor outcome despite successful recanalization. We aimed to assess the optimal cutoff for hypoperfusion volume, defined as Tmax > 6-seconds lesion size, to identify a malignant profile in LICV patients and predict poor functional outcome after endovascular treatment (EVT). Materials and methods: Sixty-six consecutive LICV with multimodal CT study protocol within 24 h from onset. A receiver operating characteristic curve analysis was used to identify the optimal Tmax > 6-seconds lesion volume cutoff to define a malignant profile. Logistic regression was used to evaluate the predictive value of malignant profile for poor functional outcome (defined as modified Rankin Scale 4–6 at 3 months). Results: Tmax > 6-seconds volume had good discriminative ability for poor clinical outcome (AUC 0.85; 95 % CI 0.74–0.92). The best cut-off value for poor outcome was ≥160 mL (84 % sensitivity, 85 % specificity, 89 % positive predictive value, 80 % negative predictive value) and represented our definition of malignant profile. Among the 66 included patients, 39 (59 %) had poor functional outcome, of whom 29 (74.3 %) showed a malignant profile. The presence of malignant profile (OR = 9.11, 95 %CI = 2.78–29.80) and unsuccessful recanalization status (OR = 3.51, 95 %CI = 1.01–12.72) were independently associated with poor functional outcome in LICV patients. Patients with malignant profile showed higher hemorrhagic transformation (p = 0.026) and mortality (p = 0.013) rates compared to patients without malignant profile. Conclusions: Tmax > 6-seconds lesion volume ≥160 mL identified the malignant profile and predicts unfavorable outcome in LICV patients undergoing EVT within 24-hours from stroke onset.