Stroke prevention versus bleeding risk of vitamin-K antagonists: a double-edged sword in patients with atrial fibrillation who require surgery.

Patients with atrial fibrillation taking vitamin-K antagonists and undergoing invasive interventions or large surgery procedures are at highest risk of bleeding complications. Therefore, the temporary interruption of vitamin-K antagonists and bridging with heparin is a frequent clinical need, particularly in patients with high risk for stroke. The management of such patients is challenging because of the lack of randomized clinical trials assessing different periprocedural anticoagulation approaches and inconsistent recommendations from consensus groups. Recent non-randomized trials have helped to estimate the risks of thromboembolism and bleeding with "bridging" anticoagulation involving either low-molecular-weight heparin or intravenous unfractioned heparin. Nevertheless, there is still a clear need for randomized double-blinded controlled trials comparing efficacy and safety of the different "bridging" strategies, including unfractionated heparin and placebo comparators, in preventing thromboembolism for specific patients and procedures.