Background: In patients receiving chronic oral anticoagulation with vitamin K antagonists (VKAs) it may be necessary to temporarily discontinue VKA therapy to allow surgery or other invasive procedures to be performed, as maintaining treatment may increase the risk of bleeding during the procedure. This, however, creates a clinical dilemma, since discontinuing VKAs may place the patient at risk of thromboembolism.
Scope: We undertook a systematic narrative review of patients on chronic oral anticoagulation, requiring a periprocedural bridging therapy with heparin during invasive procedures.
Findings and recommendations: For patients requiring temporary discontinuation of VKA, current guidelines recommend the use of 'bridging' therapy with unfractionated heparin (UFH) or low-molecular-weight heparin (LMWH) in patients considered to be at intermediate-to-high risk of thromboembolism, such as those with prosthetic heart valves or atrial fibrillation. Recent studies show that LMWHs are associated with low rates of thromboembolism and, when compared with UFH, are as effective and safe as UFH when used as periprocedural bridging therapy in such patients. LMWHs also offer advantages such as ease of administration and predictable anticoagulant effects. Moreover, outpatient-based periprocedural bridging therapy with LMWH has been shown to result in significant cost savings compared with in-hospital UFH.
Conclusions: The decision to provide bridging therapy requires careful consideration of the relative risks of thromboembolism and bleeding in each patient. Based upon the studies reviewed we recommend a therapeutic dose of UFH or LMWH for patients at intermediate-to-high thromboembolic risk requiring interruption of VKA, especially for low bleeding risk procedures. We would like to propose upgrading the American College of Chest Physicians (ACCP) guideline recommendations from 2C to 1C. However, there is still a need for a randomized controlled trial on the efficacy and safety of the available bridging strategies, including heparin and placebo comparators, in preventing thromboembolism for specific patients and procedures.