LAUSR

BACKGROUND Patients with pulmonary embolism (PE) who prematurely discontinue anticoagulant therapy (<90 days) are at an increased risk for death or recurrences. METHODS We used the data from the RIETE registry to compare the prognostic ability of 5 machine-learning (ML) models and logistic regression to identify patients at increased risk for the composite of fatal PE or recurrent venous thromboembolism (VTE) 30 days after discontinuation. ML models included Decision tree, K-Nearest Neighbors algorithm, Support Vector Machine, Ensemble and Neural Network [NN]. A "full" model with 70 variables and a "reduced" model with 23 were analyzed. Model performance was assessed by confusion matrix metrics on the testing data for each model and a calibration plot. RESULTS Among 34,447 patients with PE, 1,348 (3.9%) discontinued therapy prematurely. Fifty-one (3.8%) developed fatal PE or sudden death and 24 (1.8%) had non-fatal VTE recurrences within 30 days after discontinuation. ML-NN was the best method for identification of patients experiencing the composite endpoint, predicting the composite outcome with an area under receiver operating characteristics (ROC) curve of 0.96 (95% confidence intervals [CI], 0.95-0.98), using either 70 or 23 variables captured before discontinuation. Similar numbers were obtained for sensitivity, specificity, positive predictive value, negative predictive value and accuracy. The discrimination of logistic regression was inferior (area under ROC curve, 0.76 [95% Cl 0.70-0.81]). Calibration plot showed similar deviations from the perfect line for ML-NN and logistic regression. CONCLUSIONS ML-NN method very well predicted the composite outcome after premature discontinuation of anticoagulation and outperformed traditional logistic regression.