Objective To analyze the influencing factors of repeated fluctuation of symptoms within 24 hours of intravenous thrombolysis with recombinant tissue plasminogen activator (rt-PA) in patients with cerebral ischemic stroke (CIS) based on Nomogram model.

Methods The medical records of 512 patients with CIS from January 2016 to June 2021 in Suzhou Ninth People′s Hospital were retrospectively analyzed for modeling and internal verification (internal verification group); the medical records of 1 020 CIS patients in the First Affiliated Hospital of Suzhou University and Suzhou Xiangcheng People′s Hospital were screened for external verification (external verification group). The baseline materials of patients were recorded, and CIS patients were divided into occurrence group and non-occurrence group according to occurrence of repeated fluctuation of symptoms within 24 hours of intravenous thrombolysis with rt-PA. Logistic regression analysis was used to explore the influencing factors for repeated fluctuation of symptoms within 24 hours of intravenous thrombolysis with rt-PA in patients with CIS. Nomogram was established according to the influencing factors, and Bootstrap method was used to verify the model, calculate the consistency index (C-index) and check the accuracy of the model; the area under the curve (AUC) of receiver operating characteristics (ROC) curve and calibration curve were used to evaluate the discrimination and calibration of the prediction model.

Results Among 512 patients in the internal validation group, 140 patients had repeated fluctuation of symptoms, and the incidence rate was 27.34%. Logistic regression analysis showed that the infarct site (posterior circulation), age, the National Institute of Health Stroke Scale (NIHSS) score before thrombolysis and blood glucose level were the influencing factors for repeated fluctuation of symptoms within 24 hours of intravenous thrombolysis with rt-PA in patients with CIS (OR>1, P < 0.05). The calibration degree of the Nomogram prediction model was good, and the C-index value was 0.673, indicating that the model had a good discrimination. Nomogram model was internally verified, and the ROC curve showed that the AUC of Nomogram model for predicting the risk of repeated fluctuation of symptoms within 24 hours of intravenous thrombolysis with rt-PA in patients with CIS was 0.788, which had a certain predictive value. Nomogram model was externally verified, and ROC curve showed that the AUC of Nomogram model for predicting repeated fluctuation of symptoms within 24 hours of intravenous thrombolysis with rt-PA in patients with CIS was 0.866, which had a good predictive value.

Conclusion Nomogram model based on multiple influencing factors for repeated fluctuation of symptoms within 24 hours of intravenous thrombolysis with rt-PA in patients with CIS has a certain application value, which can provide effective reference for clinical reasonable prediction.