Admission serum tropomyosin 4 levels predict 1-year functional outcomes in acute ischemic stroke

Background Tropomyosin 4 (TPM4) regulates neurite outgrowth and vascular pathology but its role as a biomarker for predicting outcomes in stroke patients is unclear. This study investigated the association between serum TPM4 levels and 1-year functional outcomes in acute ischemic stroke (AIS) patients. Methods AIS patients admitted within 24 h post-onset from the Chengdu Stroke Registry were included. Serum TPM4 levels were measured by enzyme-linked immunosorbent assay (ELISA). Poor functional outcomes were defined as a modified Rankin Scale (mRS) score >2 at 1 year after stroke onset. Multivariate logistic regression assessed TPM4’s association with outcomes, with its predictive incremental value evaluated by discrimination, reclassification, and overall performance metrics. Results Among 181 patients (median age 66 years, 64.1% male), 59 (32.6%) experienced poor outcomes at 1 year, including 16 deaths (8.8%). Serum TPM4 levels on admission were negatively correlated with the National Institutes of Health Stroke Scale (NIHSS) score ( r = −0.185, p = 0.013). Adjusted for confounders, lower serum TPM4 levels were independently associated with 1-year poor functional outcomes (adjusted OR 0.045, 95% CI [0.005–0.393], p = 0.005). Serum TPM4 levels had acceptable discriminative ability for predicting poor outcomes (AUROC 0.706, 95% CI [0.621–0.791], p < 0.0001). Incorporating TPM4 into the basic model significantly improved the predictive power for poor functional outcomes (net reclassification index: 31.87%, p = 0.041; integrated discrimination improvement: 5.01%, p = 0.008; Brier score decreased from 0.16 to 0.15, p = 0.012). Conclusions Lower serum TPM4 levels on admission were independently associated with poor functional outcomes at 1 year in AIS patients, suggesting that TPM4 may serve as a potential biomarker for long-term outcomes and offer insights into its potential role in stroke pathophysiology. These findings need to be further verified in external cohorts.