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

BACKGROUND Current stroke treatment guidelines restrict level 1A recommendations for endovascular therapy to patients with baseline ASPECTS score > 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. METHODS 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. RESULTS 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%). CONCLUSION 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