Comparison of short-and long-term prognostic differences and validation of clinical prediction models between two types of mechanical thrombectomy in patients with acute ischemic stroke aged 75 years and above

Background As the global population ages, the incidence of acute ischemic stroke (AIS) among individuals aged 75 years and older is steadily increasing. Mechanical thrombectomy (MT) has become a standard treatment for AIS, with two commonly employed approaches: bridging thrombectomy (BT) and direct mechanical thrombectomy (DMT). However, the efficacy and safety of these strategies in elderly patients remain inconclusive. Methods This single-center retrospective study included AIS patients aged 75 years and older who underwent BT or DMT at Liuan City Hospital of Traditional Chinese Medicine, affiliated with Anhui University of Traditional Chinese Medicine, between December 2020 and August 2024. After propensity score matching (PSM), patients were compared in terms of neurological outcomes (NIHSS, mRS), inflammatory markers (CRP, NLR, SII, SIRI), and complication rates at 24 h, 7 days, and 90 days post-treatment. A predictive model for 90-day functional outcome was developed using univariate and multivariate regression analyses and evaluated for performance. Results A total of 87 patients were enrolled, and CRP levels on day 7 after treatment were significantly higher in the BT group than in the DMT group ( P = 0.008). Multivariate analysis identified time to puncture, NIHSS at 24 h, and CRP at 7 days as independent predictors of 90-day poor functional outcome. Patients with a pre-puncture time >3.25 h had a 6.36-fold higher risk of poor prognosis than those with ≤ 3.25 h. For every 1 mg/L increase in C-reactive protein at 7 days postoperatively, the risk of poor prognosis increased by 2%, with a significant risk rise when the level exceeded 28.175 mg/L. Patients with a NIHSS score >14.5 at 24 h postoperatively had a 2.22-fold higher risk of poor prognosis than those with ≤ 14.5. The predictive model demonstrated high accuracy, with an area under the curve (AUC) of 0.93. And the risk value of 0.319 is the judgment point to distinguish high and low risk groups. Conclusion In AIS patients aged 75 years and older, both BT and DMT yielded comparable short- and long-term neurological outcomes. Onset Puncture Time, Postoperative NIHSS at 24 h and CRP at 7 days were key prognostic factors. The developed model may serve as a reliable tool for individualized prognosis assessment and optimization of treatment strategies in elderly stroke patients.