National Early Warning Score-2 for Identification of Patients with Intermediate-High-Risk Pulmonary Embolism

Consensus statements have proposed the use of the National Early Warning Score 2 (NEWS2) to identify stable patients with acute pulmonary embolism (PE) and an intermediate-high risk of adverse outcomes. We aimed to externally validate NEWS2 and compare it to another predictive score (Bova). Using NEWS2 (cutoff ≥5 and ≥7) and the Bova score (cutoff >4), we classified patients as intermediate-high risk (vs. non-intermediate-high risk), and we compared the test characteristics of these risk classification tools for a complicated course within 30 days after PE diagnosis. We also assessed the validity of NEWS2 for predicting a complicated course by adding the results of echocardiography and troponin testing to the model. Of the 848 enrolled patients, the NEWS2 score ≥5 classified 471 (55.5%) and the Bova score classified 37 (4.4%) as intermediate-high risk. NEWS2 had a significantly lower specificity for a 30-day complicated course than Bova (45.4 vs. 96.3%, respectively; p < 0.001). Using the higher score threshold (≥7), the NEWS2 classified 99 (11.7%) as intermediate-high risk, and the specificity was 88.9% (difference with Bova, 7.4%; p < 0.001). The proportion of patients with intermediate-high risk PE was 2.4% for the combination of a positive troponin testing and echocardiographic right ventricle dysfunction and a positive NEWS2 (score ≥7), while the specificity was 97.8% (difference with Bova, 1.5%; p = 0.07). Bova outperforms NEWS2 for predicting a complicated course among stable patients with PE. Addition of troponin testing and echocardiography improved the specificity of NEWS2, although it was not superior to Bova. CLINICALTRIALS.GOV NUMBER: : NCT02238639.