Evaluation of Venous Thromboembolism Recurrence Scores in an Unprovoked Pulmonary Embolism Population: A Post-hoc Analysis of the PADIS-PE trial

BACKGROUND: We aimed to validate the Men Continue and HERDOO2 (HERDOO2), D-dimer, age, sex, hormonal therapy (DASH), and updated Vienna recurrent venous thromboembolism prediction models in a population composed entirely of first unprovoked pulmonary embolism, and to analyze the impact of the addition of the pulmonary vascular obstruction index (PVOI) on score accuracy. METHODS: Analyses were based on the double-blind, randomized PADIS-PE trial, which included 371 unprovoked pulmonary embolism patients initially treated for 6 months, successively randomized to receive an additional 18 months of warfarin or placebo, and subsequently followed-up for 2 years. RESULTS: TheHERDOO2, DASH, and updatedVienna scores displayed C-statistics of 0.61 (95% CI 0.54-0.68), 0.60 (95% CI 0.53-0.66), and 0.58 (95% CI 0.51-0.66), respectively. Only the HERDOO2 score identified low recurrence risk patients (< 3%/year) after anticoagulation was stopped. When added to either of the prediction models, PVOI measured at pulmonary embolism diagnosis, after 6 months of anticoagulation, or both, improved scores' C-statistics between +0.06 and +0.11 points and consistently led to identifying at least 50% of patients who experienced recurrence but in whom the scores would have indicated against extended anticoagulation. CONCLUSIONS: In patientswith a first unprovoked pulmonary embolism, theHERDOO2 score is able to identify patientswith a low recurrence risk after treatment discontinuation. Addition of PVOI improves accuracy of all scores. (C) 2020 Elsevier Inc. All rights reserved.