ABSTRACT NUMBER: ESOC2026A1089 MECHANICAL THROMBECTOMY IN PATIENTS WITH LARGE VESSEL OCCLUSION AND LOW NIHSS: FUNCTIONAL AND SAFETY OUTCOMES IN THE SEVILLE-HUELVA NODE

Abstract Background and aims Mechanical thrombectomy (MT) is the standard treatment for acute ischemic stroke with large vessel occlusion (LVO) and NIHSS ≥6. Its role in NIHSS ≤5 remains controversial. 8-10.6% cases with NIHSS ≤5 have a LVO, and one-third will have mRS ≥3 at 90 days. Meta-analyses show uncertain functional benefits of MT and increased risk of symptomatic intracranial hemorrhage (sICH) compared to best-medical-treatment (BMT). Methods The ARTISTA registry prospectively records interventional stroke cases at Hospital Universitario Virgen del Rocío (Seville-Huelva node) since 2017. A retrospective cohort including all patients treated with MT, pre-procedural NIHSS 0-8 and LVO were selected. Stratifications were performed according to NIHSS, occlusion site (anterior/posterior circulation) and basal mRS. Functional and safety outcomes were studied. Results A total of 890 cases of NIHSS 0-8 were analysed (24% of total registry). 405 cases (10.9%) had NIHSS ≤5. Reperfusion TICI 2b-3 was reached in 93.7%. In anterior circulation with NIHSS ≤5, excellent (mRS 0-1) and good (mRS 0-2) functional outcome at 90 days were achieved in 68% and 82% respectively. In patients with basal mRS ≤1 functional outcomes were higher (85% and 89% respectively). sICH rate was 3.9%, in-hospital mortality 2%, and 90-day mortality 4.4%. In posterior circulation with NIHSS ≤5, excellent and good functional outcomes were 56% and 72% respectively, no sICH, but higher mortality (9.4% in-hospital; 12% at 90 days). Conclusions Mechanical thrombectomy in selected patients of our institution with LVO and low NIHSS demonstrates favorable functional and safety outcomes, specially in anterior circulation and better basal functionality. Conflict of interest Christian Norambuena Aguayo: nothing to disclose