Development and Validation of Prediction Model to Estimate Risk of Acute Pulmonary Embolism: Retrospective Cohort Study

Background: Venous thromboembolism (VTE), clinically presenting as deep vein thrombosis (DVT) or pulmonary embolism (PE). Not all DVT patients carry the same risk of developing acute pulmonary embolism (APE). Methods: : Patients who were diagnosed as symptomatic VTE between June 2013 and June 2018 (n=1582) at the First Affiliated Hospital of Xi’an Jiaotong University were enrolled in this study, of whom 783 had the DVT and APE confirmed by angiography or computed tomography pulmonary angiography (CTPA). Using the LASSO and logistics regression, we derived predictive model with 16 candidate variables to predict the risk of APE and completed internal validation. Results: : Overall, 52.9% patients had DVT+APE (773 vs 1460), 47.1% patients only had DVT (687 vs 1460). The APE risk prediction model included one pre-existing disease or condition (respiratory failure), one risk factors(infection), three symptoms (dyspnea, hemoptysis, syncope), five signs (skin cold clammy, tachycardia, diminished respiration, pulmonary rales, accentuation/splitting of P 2 , tricuspid murmur), and six ECG indicators (S Ⅰ Q Ⅲ T Ⅲ , right axis deviation, left axis deviation, S 1 S 2 S 3 , T wave inversion, Q/q wave), of which all were positively associated with APE. The ROC curves of the model showed AUC of 0.79 (95% CI, 0.77-0.82) and 0.80 (95% CI, 0.76-0.84) in the training set and testing set. The model showed good predictive accuracy (calibration slope, 0.83 and Brier score, 0.18). Conclusion: Based on a retrospective single-center population study, we developed a novel prediction model to identify patients with different risks for APE in DVT patients, which may be useful for quickly estimating the probability of APE before obtaining definitive test results and speeding up emergency management processes.