Inflammatory biomarkers, stroke severity, and 1-month outcomes in minor acute ischaemic stroke by small-vessel occlusion status

The prognostic value of systemic inflammatory biomarkers in acute ischemic stroke (AIS) remains controversial, particularly regarding whether these markers provide information beyond established clinical predictors. In addition, potential differences across stroke aetiological subtypes have not been fully clarified. We examined admission C-reactive protein (CRP), ferritin, and systemic immune-inflammation index (SII) in predominantly minor acute ischaemic stroke (AIS), with exploration by small-vessel occlusion (SVO) status. This prospective single-centre study included 64 patients (36 SVO, 28 non-SVO; median admission National Institutes of Health Stroke Scale [NIHSS], 2). Correlations underwent Benjamini–Hochberg adjustment. Separate Poisson and Firth models assessed 1-month NIHSS and modified Rankin Scale (mRS) 0–1 versus 2–6, with and without admission NIHSS. In SVO, CRP correlated with admission NIHSS (ρ = 0.431, q = 0.020), 1-month NIHSS (ρ = 0.439, q = 0.020), and admission mRS (ρ = 0.468, q = 0.012); CRP–1-month mRS did not meet the adjusted threshold (q = 0.058). In non-SVO, CRP correlated with ferritin (ρ = 0.507, q = 0.025), but no biomarker–clinical score correlation survived adjustment. Multivariable models detected no biomarker association with either outcome; 11 of 64 patients (17.2%) had a 1-month mRS score of 2–6. Admission NIHSS was associated with 1-month NIHSS (mean ratios, 1.30–1.32) and mRS 2–6 (odds ratios, 2.25–2.32; all p < 0.001). CRP correlated with baseline neurological severity and 1-month NIHSS within the SVO group, although this study could not establish whether these associations differed by TOAST subtype. Admission NIHSS was consistently associated with both 1-month outcomes. Larger, adequately powered studies are needed to determine whether inflammatory biomarkers provide prognostic information beyond established clinical measures.