Study population

This study was a predefined secondary analysis of the Theia study ({"type":"clinical-trial","attrs":{"text":"NCT02262052","term_id":"NCT02262052"}}NCT02262052), a prospective international multicenter outcome study in which we evaluated the safety of excluding recurrent ipsilateral DVT with MRDTI. The full details of the study design and outcomes have been described previously.¹³ In summary, between March 2015 and May 2019, adult patients with suspected recurrent ipsilateral proximal DVT of the lower extremity on or off anticoagulant treatment were managed according the result of the MRDTI scan. Main exclusion criteria were suspected concomitant acute PE, CUS-proven acute DVT within 6 months of presentation, and general contraindications for magnetic resonance imaging. CUS was performed as a reference examination in all patients with a MRDTI negative for DVT to guide diagnostic testing if suspected recurrence occurred during follow-up. Furthermore, the protocol dictated CDR assessment using the original Wells rule and D-dimer testing in all patients. Importantly, CUS, CDR assessment, and D-dimer results did not influence management decisions. All included patients were followed for a 3-month period for the occurrence of recurrent VTE (DVT or PE), anticoagulation-associated major bleeding, and all-cause mortality. For the current analysis, the results of the Theia study were extrapolated to the Dutch situation, excluding patients who were on anticoagulant treatment ≥48 hours before inclusion.