Abstract
A recent randomized controlled clinical trial expanded the time window of intravenous thrombolysis (IVT) in patients with acute ischemic stroke (AIS) beyond 4.5 hours by applying neuroimaging standards, enabling more patients to benefit from IVT. However, hemorrhagic transformation (HT) after IVT is still a major concern. We aimed to develop a nomogram to predict HT in AIS patients receiving IVT with extended time window. We aimed to develop a nomogram to predict HT in AIS patients receiving IVT with extended time window. Patients with AIS receiving IVT with extended time window from March 2017 to April 2023 were retrospectively reviewed. They were divided into the HT group and the non-HT group based on computed tomography. Logistic regression analysis was used to screen the predictive factors for HT. A nomogram was developed based on the predictive factors. The predictive accuracy of the nomogram was assessed by the area under the curve (AUC) of the receiver operating characteristic curve (ROC). A calibration plot was used to evaluate the calibration of the nomogram. A decision curve analysis (DCA) was used to test the clinical value. A total of 210 patients were enrolled, and 44 patients (21.0%) had HT. Onset to needle time (ONT) (OR = 1.002, 95% CI: 1.000-1.004, P = .016), atrial fibrillation (OR = 2.853, 95% CI: 1.072-7.594, P = .036), and baseline NIHSS (OR = 1.273, 95% CI: 1.159-1.399, P = .000) were predictive factors of HT. The AUC of the nomogram was 0.833 (95% CI: 0.7623-0.9041), with a sensitivity of 78.9% and specificity of 77.3%. The calibration curve indicates that predicted results of the nomogram were in good agreement with the actual observation results. The DCA showed the nomogram had good clinical applicability in predicting HT. We developed an easy-to-use nomogram to predict HT in AIS patients receiving IVT with extended time window. It could be a potential tool to stratify the risk of HT for patients beyond 4.5 hours of onset who may undergo IVT.