What is bridging anticoagulation in preoperative patients requiring anticoagulant therapy?

Bridging Anticoagulation in Preoperative Patients

Bridging anticoagulation refers to the temporary use of short-acting anticoagulants, typically low-molecular-weight heparin (LMWH) or unfractionated heparin (UFH), during the perioperative period when long-term oral anticoagulants like vitamin K antagonists (VKAs) are interrupted to reduce bleeding risk during surgery. 1

Risk Stratification for Bridging Decisions

The decision to bridge depends primarily on the patient's thromboembolic risk:

High Thromboembolic Risk (Bridging Recommended)

• Mechanical heart valve (especially mitral valve or older-generation aortic valve) 1
• Atrial fibrillation with high CHA₂DS₂-VASc score (≥7) or CHADS₂ score (5-6) 1, 2
• Recent venous thromboembolism (VTE) within 3 months 1, 3
• Severe thrombophilia with recent thrombosis 3
• Selected types of active cancer 1

Low Thromboembolic Risk (No Bridging Recommended)

• Bileaflet mechanical aortic valve without additional risk factors 1
• Atrial fibrillation with low CHA₂DS₂-VASc score (≤2) without prior stroke/TIA 2
• VTE >3 months ago 1, 3

Standard Bridging Protocol

Preoperative Management

• Stop VKA approximately 5 days before surgery to allow INR to normalize 1, 2
• For high-risk patients, start LMWH 36-48 hours after the last VKA dose (typically 3 days preoperatively) 1
• Stop LMWH 24 hours before surgery 1
• For patients with impaired renal function, decrease LMWH dose or hold for longer than 24 hours before surgery 1

Postoperative Management

• Resume VKA 12-24 hours after surgery when adequate hemostasis is achieved 1, 2
• For high-risk patients requiring bridging, resume LMWH 24 hours after surgery or when bleeding has almost completely subsided 1
• Continue LMWH until INR reaches therapeutic range on 2 separate measurements 1

Special Considerations

Minor Procedures

• For procedures with minimal bleeding risk (dental extractions, cataract removal), continuing VKA with therapeutic INR is recommended 1
• Local hemostatic measures can be used to control bleeding 2

Mechanical Heart Valves

• Bridging is recommended for patients with mechanical mitral valve replacement or older-generation mechanical AVR 1
• For bileaflet mechanical AVR without risk factors, temporary interruption without bridging is recommended 1

Patients with Coronary Stents

• Elective surgery should be deferred for at least 6 weeks after bare-metal stent placement and 6 months after drug-eluting stent placement 1, 2
• Only lifesaving procedures should be performed during these critical periods with continuation of antiplatelet therapy 1

Risks and Benefits of Bridging

Risks

• Increased bleeding complications with bridging therapy 1, 4
• Major bleeding rates of 1-2% reported in studies 1, 5
• Particularly high bleeding risk in total joint arthroplasty patients 4

Benefits

• Reduced thromboembolic events in high-risk patients 1
• Effective management of the perioperative anticoagulation gap 5, 6

Practical Implementation

• Use a perioperative VKA and heparin bridging calendar (paper or electronic) to minimize errors 1
• Consider outpatient-based bridging therapy with LMWH for cost savings compared to in-hospital UFH 7
• UFH is typically reserved for patients with creatinine clearance <30 ml/min and high thromboembolism risk 1

Bridging anticoagulation represents a careful balance between preventing thromboembolism and avoiding excessive bleeding. The decision should be based on individual thromboembolic risk factors and the bleeding risk of the procedure, with bridging generally recommended only for patients at high risk for thromboembolism 1.