A Simple Risk Index Predicts Endovascular Treatment Outcomes in Acute Ischemic Stroke: Prognostic Value of SPAN-100.

noemie ligot¹marie dagonnier²boris lubicz²nicolas brassart²Gilles Naeije^1*

• ¹Université libre de Bruxelles, Brussels, Belgium
• ²CHU HELORA - Kennedy, Mons, Belgium, mons, Belgium

Background:Mechanical thrombectomy (MT) is a proven intervention for patients with acute ischemic stroke (AIS) due to large vessel occlusion (LVO). However, outcomes after MT remain variable, particularly in high-risk groups. The SPAN-100 index, a simple bedside tool combining age and baseline NIHSS, has been associated with poor outcomes in AIS patients treated with intravenous thrombolysis. This study evaluates the prognostic value of SPAN-100 and its weighted variant (wSPAN) in predicting outcomes following MT.Methods:We conducted a retrospective cohort study of patients with AIS treated with MT between 2015 and 2024 at two Belgian university hospitals. SPAN and wSPAN scores were calculated at admission and patients were stratified by SPAN ≥100 vs. <100. The primary outcome was functional status at 90 days assessed using the modified Rankin Scale (mRS). Secondary outcomes included mortality (mRS = 6) and favorable outcome (mRS ≤3). Discriminative ability was assessed using receiver operating characteristic (ROC) analysis ). PPV and NPV were calculated for SPAN ≥100, and outcome proportions were compared between SPAN-defined groups using Fisher’s exact test.Results:A total of 530 patients were included, of whom 116 had SPAN ≥100. These patients had significantly worse outcomes, with higher mortality (60.0% vs. 17.6%) and lower rates of mRS ≤3 (19.2% vs. 71.6%, both p < 0.001). However, among SPAN ≥100 survivors, nearly half achieved meaningful recovery (mRS ≤3). ROC analysis showed good discrimination for both SPAN and wSPAN: AUCs were 0.77 and 0.78 for mRS ≤3, and 0.80 and 0.81 for mortality. wSPAN showed slightly better model fit (lower AIC/BIC). The SPAN ≥100 threshold had a high PPV for poor outcome and high NPV for survival.Conclusions:SPAN-100 and wSPAN are pragmatic and reliable prognostic tools in AIS patients undergoing MT. While SPAN ≥100 identifies a high-risk group with poorer overall outcomes, it should not be used as an exclusion criterion. Many SPAN ≥100 patients achieve functional recovery, supporting MT as a justified intervention even in older, more severely affected individuals. These findings highlight the importance of combining risk stratification with clinical judgment rather than relying on rigid thresholds.