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

Abstract

BackgroundWe 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. MethodsAnalyses 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. ResultsThe HERDOO2, DASH, and updated Vienna 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. ConclusionsIn patients with a first unprovoked pulmonary embolism, the HERDOO2 score is able to identify patients with a low recurrence risk after treatment discontinuation. Addition of PVOI improves accuracy of all scores. Clinical Trials RegistrationURL: http://www.controlled-trials.com. Unique identifier: NCT00740883.