Integrating Traditional Chinese Medicine Syndrome Score with NIHSS for Improved Prognostic Evaluation in Acute Ischemic Stroke

Aim To investigate whether the traditional Chinese medicine (TCM) heat syndrome score (HSS), alone or in interaction with the National Institutes of Health Stroke Scale (NIHSS), provides additional prognostic information for 90-day functional outcomes in patients with large-artery atherosclerotic acute ischemic stroke (AIS). Methods A total of 149 patients with large-artery atherosclerotic AIS admitted to Xuanwu Hospital, Capital Medical University, between December 2017 and December 2023 were retrospectively included. Demographic characteristics, medical history, laboratory parameters, clinical scores, and inflammatory indices, the neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR), platelet-to-lymphocyte ratio (PLR), and systemic inflammation response index (SIRI), were collected or calculated. Multivariable logistic regression was used to evaluate factors associated with poor 90-day functional outcome (mRS ≥3). An interaction term (NH), defined as the product of mean-centered NIHSS and HSS, was evaluated in the prognostic model. Firth penalized logistic regression, subgroup and sensitivity analyses, ROC analysis, bootstrap internal validation, and restricted cubic spline analysis were additionally performed. Results Among 149 patients, 55 (36.9%) had a poor functional outcome at 90 days. HSS alone was not independently associated with poor outcome, whereas lnNLR remained independently associated with outcome after multivariable adjustment. NH was significantly associated with poor functional outcome in the primary model (OR = 1.072, P = 0.005), and the association remained robust in Firth penalized regression and sensitivity analyses. Adding NH to the Base model resulted in a modest numerical increase in discrimination (AUC = 0.795 vs. 0.760), although the difference was not statistically significant by DeLong’s test ( P = 0.098). Exploratory mediation analysis provided no evidence that C-reactive protein (CRP) mediated the association between NH and poor functional outcome. Conclusion The interaction between NIHSS and HSS was associated with 90-day functional outcome in patients with large-artery atherosclerotic AIS and may provide additional prognostic information beyond conventional clinical factors. However, its incremental predictive value was modest and requires confirmation in larger independent external validation cohorts before clinical implementation.