Application of machine learning algorithms in electronic medical records to predict amputation-free survival after first revascularization in patients with peripheral artery disease

Background This study aimed to apply eight machine learning algorithms to develop the optimal model to predict amputation-free survival (AFS) after first revascularization in patients with peripheral artery disease (PAD). Methods Among 2130 patients from 2011 to 2020, 1260 patients who underwent revascularization were randomly assigned to training set and validation set in an 8:2 ratio. 67 clinical parameters were analyzed by lasso regression analysis. Logistic regression, gradient boosting machine, random forest, decision tree, eXtreme gradient boosting, neural network, Cox regression, and random survival forest (RSF) were applied to develop prediction models. The optimal model was compared with GermanVasc score in testing set comprising patients from 2010. Results The postoperative 1/3/5-year AFS were 90%, 79.4%, and 74.1%. Age (HR:1.035, 95%CI: 1.015–1.056), atrial fibrillation (HR:2.257, 95%CI: 1.193–4.271), cardiac ejection fraction (HR:0.064, 95%CI: 0.009–0.413), Rutherford grade ≥ 5 (HR:1.899, 95%CI: 1.296–2.782), creatinine (HR:1.03, 95%CI: 1.02–1.04), surgery duration (HR:1.03, 95%CI: 1.01–1.05), and fibrinogen (HR:1.292, 95%CI: 1.098–1.521) were independent risk factors. The optimal model was developed by RSF algorithm, with 1/3/5-year AUCs in training set of 0.866 (95% CI:0.819–0.912), 0.854 (95% CI:0.811–0.896), 0.844 (95% CI:0.793–0.894), in validation set of 0.741 (95% CI:0.580–0.902), 0.768 (95% CI:0.654–0.882), 0.836 (95% CI:0.719–0.953), and in testing set of 0.821 (95%CI: 0.711–0.931), 0.802 (95%CI: 0.684–0.919), 0.798 (95%CI: 0.657–0.939). The c-index of the model outperformed GermanVasc Score (0.788 vs 0.730). A dynamic nomogram was published on shinyapp (https://wyy2023.shinyapps.io/amputation/). Conclusion The optimal prediction model for AFS after first revascularization in patients with PAD was developed by RSF algorithm, which exhibited outstanding prediction performance.