The role of heparin lead-in in the real-world management of acute venous thromboembolism: The PREFER in VTE registry.

Introduction: The appropriate strategy for initiating oral anticoagulant (OAC) therapy after an acute venous thromboembolism (VTE) depends on the intermediate-term anticoagulant to be used. While heparin bridging to vitamin K antagonists (VKA) is required, the direct oral anticoagulants (DOAC) rivaroxaban (30mg/day) and apixaban (10mg/day) can be initiated directly without parenteral anticoagulation. The objective was to evaluate OAC initiation patterns in clinical practice.

Materials And Methods: PREFER in VTE was an international, non-interventional registry conducted between January 2013 and August 2015. Consecutive acute VTE patients were grouped based on their OAC treatment at 1month after the index event (VKA or DOAC).

Results: At 1month, 825 patients were receiving a VKA and 687 a DOAC (rivaroxaban in 685/687 cases). DOAC patients were significantly younger, less comorbid, at a lower bleeding risk, and less frequently diagnosed with pulmonary embolism (34.4% vs. 44.7%). During the first month after VTE, the most common treatment pattern was heparin-OAC overlap for VKA patents (69.6%), and OAC only for DOAC patients (49.1%). However, 28.8% of DOAC patients received a heparin-OAC overlap (median heparin duration: 3days; IQR: 2-6) and 14.8% were switched from heparin to DOAC. For those on rivaroxaban at 1month, only 29.7% had received the initial 30mg/day recommended dose. Clinical event rates were comparable between the DOAC only, heparin-DOAC switch, and heparin-DOAC overlap subgroups at 1 and 6months.

Conclusions: Guidelines for DOAC/rivaroxaban initiation after VTE are often not adhered to in clinical practice. This could result in adverse outcomes or suboptimal anticoagulation. Intervention programs to raise awareness amongst physicians may be merited.