Predictors of 30-Day Mortality Using Machine Learning Approach following Carotid Endarterectomy: An Insight from National Surgical Quality Database

BACKGROUND: Pre-operative prognostication of 30-day mortality in patients with carotid endarterectomy (CEA) can optimize surgical risk stratification and guide the decision-making process to improve survival. To develop and validate a set of predictive variables of 30-day mortality following CEA. METHODS: The patient cohort was identified from the American College of Surgeons National Surgical Quality Improvement Program (2005-2016). We performed logistic regression (enter, stepwise and forward) and least absolute shrinkage and selection operator (LASSO) method for selection of variables, which resulted in 28-candidate models. The final model was selected based upon clinical knowledge and numerical results. RESULTS: Statistical analysis included 65,807 patients with 30-day mortality in 0.7% (n=466) patients. The median age of our cohort was 71.0 years (range, 16-89 years). The model with 9-predictive factors which included: age, body mass index, functional health status, American society of anesthesiologist grade, chronic obstructive pulmonary disorder, preoperative serum albumin, preoperative hematocrit, preoperative serum creatinine and preoperative platelet count—performed best on discrimination, calibration, Brier score and decision analysis to develop a machine learning algorithm. Logistic regression showed higher AUCs than LASSO across these different models. The predictive probability derived from the best model was converted into an open-accessible scoring system. CONCLUSION: Machine learning algorithms show promising results for predicting 30-day mortality following CEA. These algorithms can be useful aids for counseling patients, assessing pre-operative medical risks, and predicting survival after surgery.