Endovascular Treatment Decision Making in Patients with Low Baseline ASPECTS: Insights from UNMASK EVT, an International Multidisciplinary Study

•Low baseline ASPECTS scores were significantly associated with a decision to refrain from EVT under physicians’ current local resources (aOR 1.09, CI 1.05–1.13) and under assumed ideal conditions (aOR:1.12, CI 1.08–1.16).•Nevertheless, more 50% of the participants would offer EVT in patients with baseline ASPECTS 5. However, a recent meta-analysis from the HERMES-group showed treatment benefit in patients with ASPECTS ≤ 5. We aimed to explore how physicians across different specialties and countries approach endovascular treatment decision-making in acute ischemic stroke patients with low baseline ASPECTS. In a multidisciplinary survey, 607 stroke physicians were randomly assigned 10 out of a pool of 22 case-scenarios, 3 of which involved patients with low baseline ASPECTS (A:40-year old with ASPECTS 4, B:33-year old with ASPECTS 2 C:72-year old with ASPECTS 3), otherwise fulfilling all EVT-eligibility criteria. Participants were asked how they would treat the patient A) under their current local resources and B) under assumed ideal conditions, without any external (monetary, policy-related or infrastructural) restraints. Overall and scenario-specific decision rates were calculated. Clustered multivariable logistic regression analysis was used to determine the association of baseline ASPECTS with endovascular treatment-decision. Baseline ASPECTS score was significantly associated with current (OR:1.09, CI 1.05–1.13) and ideal endovascular treatment-decision (OR:1.12, CI 1.08–1.16). Overall current and ideal treatment decision-rates for the low ASPECTS scenarios were 57.1% and 57.6%. Current and ideal rates for the two younger patients were higher (scenario A:69.9/60.4%, scenario B:60.0/61.5%) compared to the 72-year old patient (41.3/40.2%). Most physicians decided to proceed with endovascular treatment despite low baseline ASPECTS, particularly in younger patients. This may have implications on the design and execution of low ASPECTS randomized trials.