Correlations of thrombus MMP-9 level with clinical characteristics and inflammatory markers in acute ischemic stroke

To investigate the associations between thrombus Matrix Metalloproteinase-9 (MMP-9) level and the systemic inflammatory characteristics in patients with Acute Ischemic Stroke (AIS), and to evaluate the value of thrombus MMP-9 as a prognostic indicator of AIS. This study enrolled 31 patients with AIS according to both clinical and imaging diagnostic criteria. All patients underwent mechanical thrombectomy within 24 h of symptom onset. The demographic data and basic clinical information were recorded. Mean optical density (MOD) of MMP-9 in thrombi and serum inflammatory markers were measured. Correlation between thrombus MMP-9 MOD and serum inflammatory markers was analyzed. Independent risk factors for long-term prognosis were identified using multivariate logistic regression. The predictive value of thrombus MMP-9 for AIS outcomes was assessed via ROC curve analysis. MOD of thrombus MMP-9 was significantly correlated with peripheral blood neutrophil-to-lymphocyte ratio (NLR), absolute neutrophil count (ANC), C-reactive protein-to-albumin ratio (CAR), absolute lymphocyte count (ALC), and monocyte-to-lymphocyte ratio (MLR). Patients with higher MMP-9 level exhibited significantly higher admission National Institutes of Health Stroke Scale (NIHSS) scores, 90-day modified Rankin Scale (mRS) scores, incidence of hemorrhagic transformation (HT), and pneumonia rate compared to those with lower MMP-9 level. Patients with poor outcomes had higher thrombus MMP-9 level, higher prevalence of hypertension, more thrombectomy device passes, longer puncture-to-recanalization time, higher HT rates, higher admission NIHSS scores, higher NLR, higher MLR, and higher pneumonia incidence, but lower rates of successful recanalization after the first thrombectomy pass. Furthermore, higher thrombus MMP-9 level may serve as an independent risk factor for poor 3-month functional outcomes. ROC analysis showed that thrombus MMP-9 was associated with poor outcomes with an area under the curve (AUC) of 0.915 (sensitivity 87.1%, specificity 87.5%). High thrombus MMP-9 level correlates with systemic inflammatory markers, clinical severity, 3-month poor outcomes, and incidence of complications (including HT and pneumonia). These findings suggest thrombus MMP-9 may serve as a potential prognostic biomarker; however, larger multicenter studies are required for validation.