ABSTRACT NUMBER: ESOC2026A1374 EFFECT OF BASELINE PERFUSION IMAGING PARAMETERS ON ENDOVASCULAR TREATMENT OUTCOMES IN MEDIUM OR DISTAL VESSEL OCCLUSION STROKE: A SECONDARY ANALYSIS OF THE DISTAL TRIAL

Abstract Background and aims The DISTAL trial compared endovascular treatment (EVT) plus best medical treatment (BMT) to BMT alone in medium or distal vessel occlusion (MDVO) stroke and showed no overall benefit of EVT. It is unclear whether perfusion imaging characteristics can identify subgroups who may benefit from EVT. Methods Patients of the DISTAL trial with high-quality perfusion imaging were included (n = 455). Perfusion parameters included ischemic core volume (relative cerebral blood flow [CBF] < 38%), hypoperfused volume (Tmax>6 s), perfusion mismatch volume (Tmax>6 s—CBF < 38% > =10 mL), hypoperfusion intensity ratio (HIR; volume of Tmax>10s/Tmax>6 s) and relative cerebral blood volume (rCBV)-Index (mean CBV within the Tmax>6 s lesion/mean CBV of the unaffected, contralateral side). Primary outcome was the 90-day modified Rankin Scale (mRS) score, analyzed using ordinal regression with interaction terms between treatment arm and perfusion variables. Results Lower core volume (OR:0.97, 95%-CI:0.95–0.99) and present perfusion mismatch (OR:2.04, 1.06–3.95) were independently associated with better 90-day functional outcome, while hypoperfused volume was not (OR: 1.01, 0.99–1.02). The parameters did not modify the treatment effect of EVT (OR:1.01, 0.97–1.04; OR:0.94, 0.38–2.34, and OR:1.00, 0.99–1.02). Higher CBV-Index (>1.0) and higher HIR (>0.4) were associated with greater benefit from EVT. Conclusions In MDVO patients, volume-based imaging parameters at baseline are prognostic but cannot alone identify patients who benefit from EVT, while CBV-Index and HIR may help select patients more likely to benefit. These findings underscore the potential for individualized EVT decision-making guided by perfusion imaging and warrant further investigation. Conflict of interest JS discloses a speaker fee for Medtronic. GA reports consulting and equity from iSchemaView. JH is a consultant for Medtronic and MicroVention and a member of medical advisory boards for iSchemaView and MicroVention. UF reported research support of the Swiss National Science Foundation and the State Secretariat for Education, Research and Innovation; research support of the Swiss Heart Foundation, the Swiss Brain League and the Horton Foundation; research grants from Medtronic and from Stryker, Rapid medical, Penumbra, Medtronic and Phenox, Boehringer Ingelheim; consultancies for Medtronic, Bayer, Boehringer Ingelheim, Boston Scientific, CSL Behring, Merck, Siemens and Takeda (fees paid to institution). Participation in an advisory board for AstraZeneca (former Alexion/Portola), Auzone, Biogen, AbbVie, Siemens, Corxel (fees paid to institution). Member of a clinical event committee (CEC) of the COATING study (Phenox). Member of the data and safety monitoring committee (DSMB) of the TITAN, RESCIND, LATE_MT, IN EXTREMIS and RapidPulse trials. Past president of the Swiss Neurological Society and president-elect of the European Stroke Organization. MP received research grants from the Swiss National Science Foundation (SNF) and Bangerter-Rhyner Stiftung, received unrestricted grant support from Medtronic Inc., Rapid Medical Inc., Penumbra Inc., Siemens Healthineers AG, Stryker Neurovascular Inc., Phenox GmbH (paid to institution), received speaker fees from Stryker Neurovascular Inc., Medtronic Inc., Penumbra Inc., Acandis GmbH, Phenox GmbH, Rapid Medical Inc., Siemens Healthineers AG (paid to institution) and is Sponsor-PI of the DISTAL Trial, SPINNERS Trial, ICARUS Trial. VA, SD, AVE, NR and AB have nothing to disclose. Figure 1 - belongs to Results