Multimodal integration of carotid plaque ultrasound radiomics and dynamic systemic immune-inflammation trajectories for subacute risk stratification after stroke thrombectomy: development and internal validation of an exploratory prognostic model

Abstract

BACKGROUND We hypothesized that integrating macroscopic carotid plaque architecture, quantified via ultrasound radiomics, would yield a highly accurate prognostic framework for 90-day functional outcomes in patients undergoing EVT. METHODS This single-center, retrospective cohort study consecutively included 316 AIS-LVO patients who underwent successful EVT (modified Thrombolysis in Cerebral Infarction score ≥2b) within 24 hours of symptom onset. Patients were partitioned into a discovery (N=221) and an internal validation cohort (N=95) using stratified random sampling. To capture temporal inflammatory heterogeneity, the SII was measured at days 0, 1, 3, and 7, and clustered using LCMM. Concurrently, high-dimensional radiomic features strictly adhering to the IBSI guidelines were extracted from baseline two-dimensional carotid ultrasound images. A radiomics score (Rad-score) was constructed utilizing LASSO regression. Four progressive predictive models were developed, culminating in an Extreme Gradient Boosting (XGBoost) multimodal architecture. The primary endpoint was an unfavorable 90-day functional outcome (modified Rankin Scale score 3 to 6). RESULTS An unfavorable outcome occurred in 166 of 316 patients (52.5%). The LCMM objectively identified three longitudinal SII phenotypes. The "persistent high-inflammation" trajectory (Class 3, 17.0% of patients) was independently associated with an increased risk of an unfavorable outcome compared to the "rapid resolution" trajectory (Class 1) (adjusted odds ratio [aOR], 4.85; 95% confidence interval [CI], 2.20 to 10.85; P<0.001). The ultrasound Rad-score, comprising 9 core textural features, also demonstrated robust independent predictive value (aOR, 1.52; 95% CI, 1.21 to 1.92 per 0.1-point increase; P<0.001). In the strictly isolated internal validation cohort, the full multimodal XGBoost model achieved an area under the receiver operating characteristic curve (AUC) of 0.92 with an accuracy of 86.3%, sensitivity of 88.0%, and specificity of 84.4%. This performance was statistically superior to the standard clinical baseline model (AUC, 0.74; 95% CI, 0.63 to 0.84; P<0.001 via DeLong test). Furthermore, the multimodal paradigm demonstrated clinical reclassification utility, yielding a continuous net reclassification improvement of 0.985 and an integrated discrimination improvement of 0.194 (95% CI, 0.128 to 0.260). CONCLUSIONS An exploratory model integrating baseline carotid plaque ultrasound radiomics with Day-0-to-Day-7 systemic immune-inflammation trajectories was associated with 90-day functional outcome after EVT and, on internal validation.