Risk factors and predictive model for non-aspiration stroke-associated infections in patients with acute ischemic stroke followed by intravenous thrombolysis.

This study aims to analyze the clinical characteristics, risk factors, and prediction model of non-aspiration stroke-associated infections (NASAI) in patients with acute ischemic stroke (AIS) who received intravenous alteplase thrombolysis. This prospective cohort study included patients with AIS from the Dalian Single-center Study on Intravenous Thrombolysis for Ischaemic Stroke (DATIS) cohort, who received intravenous alteplase thrombolysis at the Central Hospital of Dalian University of Technology (Dalian Central Hospital) from January 2018 to July 2024. Patients developing stroke associated infection (SAI) were classified as NASAI when lacking high risks of aspiration (altered level of consciousness, bulbar palsy, or nasogastric tube retention). Clinical characteristics and risk factors of infection between the NASAI group and non-infection (NI) patients were explored. For this purpose, patients were randomly split into a training set and a validation set at a ratio of 7:3 (1171 and 503). In the training set, logistic regression and LASSO regression analyses were used to select the predictive factors and a prediction model was constructed and evaluated the performance using the receiver operating characteristic curve (ROC), calibration curve (CC), and decision curve analysis (DCA). A total of 1828 AIS patients who received intravenous thrombolysis with alteplase were included in this study. The prevalence of NASAI was 196 (10.72%) which represented 56% of the total SAI cases (n = 350). There were statistically significant differences between NASAI and NI groups in terms of age, hypertension, diabetes, NIHSS score on admission, mRS score on admission, and heart rate (p < 0.05). Lower respiratory tract infections were the predominant type of infection. Older age (OR: 1.62, 95% CI 1.08-2.42, p = 0.020), presence of hypertension (1.64, 1.15-2.35, p = 0.006), higher admission values of NIHSS (4.03, 2.77-5.88, p < 0.001), heart rate (1.06, 1.05-1.08, p < 0.001), and white blood cell count (1.16, 1.07-1.26, p = 0.001) were independently associated with a higher risk of developing NASAI. In the training set of combined NASAI and NI patients, multivariate logistic regression analysis identified age, hypertension, NIHSS score on admission, heart rate, and white blood cell count, as the final predictive variables hence integrated in the nomogram. The AUC of the model in the training set and validation set were 0.80 and 0.78, respectively, indicating good discrimination. The CC showed excellent match of the model's predicted probability and the actual occurrence probability. The DCA indicated that the model had a high net benefit for predicting NASAI and good clinical practicality. We developed an internally validated nomogram with strong predictive performance using easily accessible five variables hence offering a practical tool for early risk assessment and targeted intervention, potentially improving outcomes in high-risk stroke patients. This study highlights the clinical importance of NASAI in thrombolyzed AIS patients.