Post‐thrombotic syndrome in patients with venous thromboembolism treated with dabigatran or warfarin: A long‐term cross‐sectional follow‐up of RE‐COVER study patients

BACKGROUND: Studies suggest that the direct factor Xa inhibitor rivaroxaban compared to warfarin reduces the risk of post-thrombotic syndrome (PTS) after deep vein thrombosis (DVT), but this has not been evaluated for oral direct thrombin inhibitors. OBJECTIVES: To compare the long-term prevalence of PTS, recurrent venous thromboembolism (VTE), and health-related quality of life (HRQoL) in patients with acute DVT and/or pulmonary embolism (PE), randomized to treatment with dabigatran or warfarin in the phase III RE-COVER studies. METHODS: We conducted a cross-sectional follow-up study of patients randomized in Canada, Norway, and Sweden. PTS was assessed by the patient-reported Villalta scale (PRV) and HRQoL by EQ-5D and VEINES-QOL/Sym. RESULTS: We included 349 patients between December 2015 and November 2018; 166 were treated with dabigatran and 183 with warfarin. DVT (+/- PE) was index event in 255 patients, whereas 94 patients had PE only. Mean time from index event was 8.7 (standard deviation 1.4) years. PTS was diagnosed in 63% of patients with DVT and in 46% of patients with PE only, and did not differ between the treatment groups; the crude odds ratio (OR) for PTS in patients treated with dabigatran compared with warfarin was 1.1 (95% confidence interval [CI] 0.6-1.8) after DVT and 1.2 (95% CI 0.5-2.6) after PE only. The prevalence of recurrent VTE was 21% in both treatment groups. HRQoL scores did not differ between groups. CONCLUSION: In this long-term cross-sectional study, the prevalence of PTS, recurrent VTE, and HRQoL were similar in patients treated with dabigatran and warfarin.