Perioperative management of oral anticoagulation: when and how to bridge.

The management of patients on oral anticoagulation (OAC) who need to undergo surgery or invasive procedures is problematic. "Bridging" the subtherapeutic periods with either intravenous unfractionated heparin or subcutaneous treatment-dose low-molecular-weight heparin (LMWH) decreases the amount of time patients are not anticoagulated but may increase the risk of postoperative bleeding and is costly. The available literature does not provide sufficient information to allow clinicians to choose an optimal perioperative strategy. Recent studies primarily have examined the perioperative use of LMWH, and have found arterial thromboembolic rates of 0.4-1.5%. The observed incidence is greater than mathematically predicted, which may be due to a potential hypercoagulable state impacting the risk for arterial thromboembolic events. The literature suggests that major postoperative bleeding is low for invasive procedures but may be substantially higher for major surgery. Given the lack of definitive data or consensus, the decision must be based on estimates of the risks of thromboembolism and bleeding and the patient's preference. For most patients at low or moderate stroke risk, bridging will be unnecessary and may be harmful. Bridging is recommended for patients who have a high annual risk of stroke and thus have a more appreciable perioperative stroke risk. Postoperative anticoagulation must be used cautiously and patients monitored closely after major surgery due to the risk of postoperative major bleeding.