ObjectiveTo explore the utility of machine learning-based radiomics models for risk stratification of severe asymptomatic carotid stenosis (ACS). MethodsThe clinical data and head and neck CT angiography images of 188 patients with severe carotid artery stenosis at the Department of Cardiovascular Surgery, China-Japan Friendship Hospital from 2017 to 2021 were retrospectively collected. The patients were randomly divided into a training set (n=131, including 107 males and 24 females aged 68±8 years), and a validation set (n=57, including 50 males and 7 females aged 67±8 years). The volume of interest was manually outlined layer by layer along the edge of the carotid plaque on cross-section. Radiomics features were extracted using the Pyradiomics package of Python software. Intraclass and interclass correlation coefficient analysis, redundancy analysis, and least absolute shrinkage and selection operator regression analysis were used for feature selection. The selected radiomics features were constructed into a predictive model using 6 different supervised machine learning algorithms: logistic regression, decision tree, random forest, support vector machine, naive Bayes, and K nearest neighbor. The diagnostic efficacy of each prediction model was compared using the receiver operating characteristic (ROC) curve and the area under the curve (AUC), which were validated in the validation set. Calibration and clinical usefulness of the prediction model were evaluated using calibration curve and decision curve analysis (DCA). ResultsFour radiomics features were finally selected based on the training set for the construction of a predictive model. Among the 6 machine learning models, the logistic regression model exhibited higher and more stable diagnostic efficacy, with an AUC of 0.872, a sensitivity of 100.0%, and a specificity of 66.2% in the training set; the AUC, sensitivity and specificity in the validation set were 0.867, 83.3% and 78.8%, respectively. The calibration curve and DCA showed that the logistic regression model had good calibration and clinical usefulness. ConclusionThe machine learning-based radiomics model shows application value in the risk stratification of patients with severe ACS.
Objective To identify the preoperative risk factors for prolonged mechanical ventilation (PMV) after pulmonary thromboendarterectomy (PTE). MethodsThe clinical data of patients who underwent PTE from December 2016 to August 2021 in our hospital were retrospectively analyzed. The patients were divided into two groups according to the postoperative mechanical ventilation time, including a postoperative mechanical ventilation time≤48 h group (≤48 h group) and a postoperative mechanical ventilation time>48 h (PMV) group (>48 h group). Univariable and logistic regression analysis were used to identify the preoperative risk factors for postoperative PMV. ResultsTotally, 90 patients were enrolled in this study. There were 40 patients in the ≤48 h group, including 30 males and 10 females, with a mean age of 45.48±12.72 years, and there were 50 patients in the >48 h group, including 29 males and 21 females, with a mean age of 55.50±10.42 years. The results showed that in the ≤48 h group, the median postoperative ICU stay was 3.0 days, and the median postoperative hospital stay was 15.0 days; in the >48 h group, the median postoperative ICU stay was 7.0 days, and the median postoperative hospital stay was 20.0 days. The postoperative PMV was significantly correlated with tricuspid annular plane systolic excursion (TAPSE) [OR=0.839, 95%CI (0.716, 0.983), P=0.030], age [OR=1.082, 95%CI (1.034, 1.132), P=0.001] and pulmonary vascular resistance (PVR) [OR=1.001, 95%CI (1.000, 1.003), P=0.028]. ConclusionAge and PVR are the preoperative risk factors for PMV after PTE, and TAPSE is the preoperative protective factor for PMV after PTE.
Objective To construct a radiomics model for identifying clinical high-risk carotid plaques. Methods A retrospective analysis was conducted on patients with carotid artery stenosis in China-Japan Friendship Hospital from December 2016 to June 2022. The patients were classified as a clinical high-risk carotid plaque group and a clinical low-risk carotid plaque group according to the occurrence of stroke, transient ischemic attack and other cerebrovascular clinical symptoms within six months. Six machine learning models including eXtreme Gradient Boosting, support vector machine, Gaussian Naive Bayesian, logical regression, K-nearest neighbors and artificial neural network were established. We also constructed a joint predictive model combined with logistic regression analysis of clinical risk factors. ResultsFinally 652 patients were collected, including 427 males and 225 females, with an average age of 68.2 years. The results showed that the prediction ability of eXtreme Gradient Boosting was the best among the six machine learning models, and the area under the curve (AUC) in validation dataset was 0.751. At the same time, the AUC of eXtreme Gradient Boosting joint prediction model established by clinical data and carotid artery imaging data validation dataset was 0.823. Conclusion Radiomics features combined with clinical feature model can effectively identify clinical high-risk carotid plaques.