6/29/23, 1:44 AM PROLONG Pathway Feedback Search Clinical Topics Home Studies PROLONG PROLONG Disease Disease Deep vein thrombosis Pulmonary embolism Trial question What is the role of D-dimer testing in determining the duration of anticoagulation therapy in patients who had a first idiopathic episode of VTE? Study design Multi-center Open label RCT Population Characteristics of study participants 53.0% female N = 223 47.0% male 223 patients (118 female, 105 male) Inclusion criteria: patients with a first unprovoked proximal deep vein thrombosis or PE who had received a vitamin K antagonist for at least 3 months and underwent D-dimer testing Key exclusion criteria: serious liver disease, renal insufficiency, other indications or contraindications for anticoagulation, or a limited life expectancy Interventions N=120 abnormal D-dimer level with discontinuation of anticoagulation (discontinuation of vitamin K antagonist therapy) N=103 abnormal D-dimer level with resumption of anticoagulation (resumption of vitamin K antagonist therapy) https://web.pathway.md/studies/recLoeLMvlBocf071 1/2 6/29/23, 1:44 AM PROLONG Pathway Primary outcome Recurrence of thromboembolism 15.0 % 15 11.3 % 7.5 % Significant increase 3.8 % 2.9 NNH = 8 0.0 % Abnormal D-dimer level with discontinuation of anticoagulation Abnormal D-dimer level with resumption of anticoagulation Significant increase in recurrence of thromboembolism (15% vs. 2.9%; aHR 4.26, 95% CI 1.23 to 14.6) Safety outcomes No significant difference in deaths. Conclusion In patients with a first unprovoked proximal deep vein thrombosis or PE who had received a vitamin K antagonist for at least 3 months and underwent D-dimer testing, abnormal D-dimer level with discontinuation of anticoagulation was inferior to abnormal D-dimer level with resumption of anticoagulation with respect to recurrence of thromboembolism. Reference Palareti G, Cosmi B, Legnani C et al. D-dimer testing to determine the duration of anticoagulation therapy. N Engl J Med. 2006 Oct 26;355(17):1780-9. Open reference URL https://web.pathway.md/studies/recLoeLMvlBocf071 2/2