Abstract DP294: FRET Score: Predictors Of Futile Recanalization Following Endovascular Thrombectomy- A Multicenter Cohort Study From The EVATRISP Collaboration

Background: Endovascular thrombectomy (EVT) is the treatment of choice for large vessel occlusion (LVO) stroke, yet nearly half of successfully recanalized patients fail to achieve functional independence, a phenomenon known as futile recanalization (FR). Despite its frequency and clinical impact, predictors of FR remain poorly defined in large, heterogeneous populations. We aimed to develop a score based on predictors of FR. Methods: Using data from the prospective, multicenter EVATRISP collaboration, we included EVT-treated LVO patients with known pre-stroke functional status, modified Thrombolysis in Cerebral Infarction (mTICI) score, and 90-day modified Rankin Scale (mRS). FR was defined as mRS ≥3 at 90 days despite mTICI ≥2b. Patients with FR were compared to those with mRS ≤2. The cohort was randomly split into derivation (70%) and validation (30%) sets. Multivariable logistic regression identified predictors used to construct the Futile Recanalization following Endovascular Thrombectomy (FRET) score, which underwent internal validation. Results: Of 9,909 patients, 73% achieved successful recanalization and 47% experienced FR. In the derivation set, FR was independently associated with older age, diabetes, ischemic heart disease, higher NIHSS, anterior cerebral artery occlusion, seizures at presentation, non-use of intravenous thrombolysis and lower ASPECTS. FR patients had more intracerebral hemorrhage, longer hospital stays and higher mortality. The FRET score demonstrated good discrimination (AUC 0.721), with FRET≥3 indicating high risk. Validation yielded similar performance (AUC 0.708). Conclusions: The FRET score enables early identification of EVT candidates at high risk for FR, supporting more selective intervention and potentially reducing futile, resource-intensive procedures.