Serum alkaline phosphatase levels at admission are associated with unfavorable prognosis in acute ischemic stroke patients undergoing endovascular thrombectomy

Background Limited data exist on the association between alkaline phosphatase (ALP) levels and outcomes in acute ischemic stroke patients undergoing endovascular thrombectomy. This study aimed to evaluate the relationship between serum ALP levels at admission and unfavorable prognosis following endovascular thrombectomy. Methods This retrospective study included patients who underwent mechanical thrombectomy for acute ischemic stroke (AIS) within 24 h of symptom onset at the Affiliated Hospital of Xuzhou Medical University between October 2018 and May 2025. Blood samples were collected upon admission in the emergency room. Unfavorable prognosis was defined as a modified Rankin Scale score of 3–6 at 90 days. Logistic regression analyses were conducted to examine the relationship between ALP levels and unfavorable prognosis. Results Of the 385 enrolled patients, 209 (54.3%) experienced an unfavorable prognosis. These patients exhibited significantly higher serum ALP levels (83.8 ± 29.5 U/L versus 76.1 ± 27.9 U/L; p = 0.009) compared to those with a favorable prognosis. A significant positive association was found between ALP levels (per 10-unit increase) and unfavorable prognosis (OR: 1.17, 95% CI: 1.06–1.29; p = 0.002) after adjusting for multiple variables. Patients in the highest ALP tertile had significantly higher odds of an unfavorable prognosis compared to those in the lowest tertile (OR: 3.17, 95% CI: 1.61–6.24; p = 0.001). The restricted cubic spline indicated a positive linear relationship between ALP levels and unfavorable prognosis ( p for non-linearity = 0.461). The association between ALP levels and unfavorable prognosis remained stable across different subgroups (all p for interaction > 0.05). Conclusion Our findings demonstrate a positive association between serum ALP levels at admission and unfavorable prognosis in patients with AIS who underwent endovascular thrombectomy.