Dabigatran Etexilate or Warfarin in the Treatment of Acute Venous Thromboembolism in Western European Patients: A Pooled Analysis of RE-COVER^® and RE-COVER II™

Introduction: In the RE-COVER^®/RE-COVER II™ global randomized trials investigating the treatment of acute venous thromboembolism (VTE), efficacy and safety outcomes of dabigatran etexilate (dabigatran) versus warfarin were compared. This sub-analysis of pooled RE-COVER^®/RE-COVER II™ data compares the safety and efficacy of dabigatran versus warfarin in the Western European sub-population.

Methods: In the RE-COVER^®/RE-COVER II™ trials, patients with acute VTE, initially receiving parenteral anticoagulation, were randomized to warfarin (INR 2-3) or dabigatran (150 mg twice daily) for 6 months and followed up for 30 days. The primary efficacy outcome was recurrent, symptomatic VTE/VTE-related death. Safety outcomes were major bleeding events (MBEs), a composite of MBEs or clinically relevant non-major bleeding events (MBEs/CRBEs) and any bleeding during the 6-month, oral-only treatment period. All outcomes were centrally adjudicated. Data from the Western European sub-population were analyzed using a Cox regression model with factor treatment stratified by study, assuming different baseline hazards per study.

Results: This sub-analysis included 1239 patients for the efficacy analysis (dabigatran n = 613; warfarin n = 626) and 1192 patients for safety (dabigatran n = 588; warfarin n = 604) from all 13 Western European countries participating in the RE-COVER^®/RE-COVER II™ trials. For the primary efficacy outcome, the rate of VTE/VTE-related death in patients receiving dabigatran was 2.1% (n = 13) compared with 2.9% (n = 18) in those receiving warfarin. However, this difference did not reach statistical significance (hazard ratio [HR] 0.74; 95% confidence interval [CI], 0.36-1.5). Of the safety outcomes, rates of MBEs were similar between both treatment groups (1.4% for dabigatran [n = 8] and 1.3% for warfarin [n = 8]; HR 1.02; 95% CI, 0.38-2.71). Rates of MBEs/CRBEs were significantly lower in patients receiving dabigatran than in those receiving warfarin at 5.1% (n = 30) and 9.4% (n = 57), respectively (HR 0.52; 95% CI, 0.34-0.82). Any bleeding events were also statistically lower in the dabigatran group (17.5%; n = 103) compared with warfarin (23.8%; n = 144) (HR 0.7; 95% CI, 0.54-0.90).

Conclusions: In this Western European sub-analysis of pooled data from the RE-COVER^®/ RE-COVER II™ trials, dabigatran was as effective as warfarin in the treatment of acute VTE. There was a significant reduction in MBE/CRBE and in any bleeding events in the dabigatran treatment group.