In a randomized trial, heparin bridging for implantation of a pacemaker or implantable cardioverter-defibrillator was associated with an increase in device-pocket hematoma.

Warfarin increases the risk for bleeding. Surgery is associated with bleeding. The intuitive inference that patients should discontinue chronic warfarin therapy before undergoing surgery, combined with concern about the ensuing thromboembolic risk, has led to the standard use of intravenous heparin or subcutaneous low-molecular-weight heparin as an anticoagulation “bridge” during warfarin washout. However, some practitioners question the benefits of this practice.

In a multicenter trial, 681 warfarin recipients undergoing permanent pacemaker or implantable cardioverter-defibrillator implantation were randomized to continue warfarin or to discontinue warfarin with a heparin bridge for 5 days before surgery. All patients had an estimated annual risk for thromboembolism of 

5% (mean CHADS₂ score, 3.4). The trial was stopped early because of a strongly significant increase in the rate of device-pocket hematoma in the heparin-bridging group compared with the warfarin-continuation group (16.0% vs. 3.5%). Two patients in the warfarin-continuation group experienced stroke or transient ischemic attack (compared with none in the heparin-bridging group); however, both had subtherapeutic international normalized ratios at the time of surgery.

Comment: These data confirm what many surgeons and electrophysiologists observe on a daily basis — heparin bridging during warfarin interruption increases bleeding risk even more than continuing warfarin does. The findings are important for patients with atrial fibrillation and a high annual risk for thromboembolism. Whether warfarin can be withheldwithout bridging in individuals at low risk for thromboembolism remains unstudied. For such patients, an effective strategy might be to stop warfarin 1 or 2 days — rather than the traditional 5 days — before surgery.

Source:Journal Watch Cardiology