Prognostic value of systemic inflammation response index in successfully recanalized acute large vessel occlusion stroke patients: a retrospective study

Background Endovascular therapy (EVT), with or without intravenous thrombolysis, is the standard reperfusion treatment for acute large vessel occlusion stroke (ALVOS). However, nearly half of the patients still experience poor functional outcomes despite successful recanalization. This study aimed to investigate the relationship between baseline Systemic Inflammation Response Index (SIRI) and 90-day functional outcomes as well as hemorrhagic transformation (HT) in successfully recanalized ALVOS patients undergoing EVT from two stroke centers in Zhejiang, China. Methods We conducted a dual-center, retrospective study enrolling 287 successfully recanalized ALVOS patients who underwent EVT. A good functional outcome was defined as a modified Rankin Scale (mRS) score of 0–2 at 90 days, while a poor outcome was defined as mRS 3–6. Univariate and multivariate logistic regression analyses were employed to explore the relationship between SIRI levels and 90-day neurological outcomes and HT. The predictive capability of SIRI for functional outcomes was assessed using receiver operating characteristic (ROC) curve analysis. Results The mean age of the 287 included patients was 70.9 ± 13.0 years, with 168 (58.5%) being male. The mean SIRI level was 1.72 ± 1.92, which was significantly lower in the good outcome group (1.26 ± 1.10) than in the poor outcome group (2.22 ± 2.42, p 0.001). The area under the ROC curve (AUC) for SIRI predicting a poor outcome was 0.63 (95% CI: 0.56–0.69, P 0.001). Incorporating SIRI into the age + NIHSS model significantly improved prognostic accuracy for 90 day outcomes (AUC increase from 0.76 to 0.79, ΔAUC = 0.035, p = 0.023). However, no significant association was found between SIRI levels and either hemorrhagic transformation (OR 1.08, 95% CI: 0.94–1.23, p = 0.29) or symptomatic intracranial hemorrhage (OR 1.12, 95% CI: 0.94–1.33, p = 0.22). Conclusion A higher baseline SIRI level is associated with 90-day poor functional outcomes in successfully recanalized ALVOS patients after EVT, but not with hemorrhagic transformation. And adding SIRI to an age + NIHSS-based model significantly enhances prognostic discrimination. SIRI may serve as a readily available biomarker associated with early functional outcomes and could have potential value in prognostic assessment.