Association between anemic status on admission and clinical outcomes of acute large vessel occlusion

Background: Anemia is a frequently observed condition, but its clinical impact on large vessel occlusion (LVO) remains unclear. We examined the association between anemic status on admission and clinical outcomes of LVO in a real-world setting. Methods: We conducted a post-hoc analysis of the RESCUE-Japan Registry 2, a nationwide registry which enrolled 2408 consecutive patients with LVO who were admitted within 24 h of onset. The patients were classified into anemia (< 11 g/dL) and no-anemia (>= 11 g/dL) groups according to their hemoglobin level on admission. The primary outcome was defined as a modified Rankin Scale of 0-2 at day 90. Results: Among the 2373 patients with available baseline hemoglobin data, 307 (13.0%) were classified in the anemia group. Anemia was associated with a lower likelihood of the primary outcome (adjusted odds ratio [OR]: 0.68; 95% confidence interval [CI]: 0.47-0.98) and higher mortality within 90 days (adjusted OR: 1.48; 95% CI: 1.01-2.17). Subgroup analyses showed that the likelihood of achieving the primary outcome between the two groups was different between men and women (P for interaction = 0.049), those with Alberta Stroke Program Early CT Score (ASPECTS) < 6 and ASPECTS >= 6 (P for interaction = 0.02), and those with National Institute of Health Stroke Scale (NIHSS) >= 16 and NIHSS < 16 (P for interaction = 0.005). Conclusions: Anemic state on admission was associated with poorer clinical outcomes of LVO in real-world clinical practice. The effects of anemic status were larger in LVO patients with lower NIHSS or higher ASPECTS.