Postoperative Low-Molecular-Weight Heparin Bridging Is Associated with an Increase in Wound Hematoma Following Surgery for Pacemakers and Implantable Defibrillators

Background: The perioperative management of patients receiving oral anticoagulation therapy (OAC) who undergo pacemaker (PM) and defibrillator (ICD) surgery remains controversial. Low-molecular-weight heparin (LMWH) is often used; however, wound hematoma is a common complication. Methods: At a single academic Canadian center, between July 2003 and June 2005, details of perioperative OAC bridging and the rate of wound hematoma requiring reoperation or interruption of OAC were reviewed for all patients receiving LMWH bridging for PM or ICD surgery. Results: A total of 148 PM/ICD patients underwent perioperative bridging with LMWH. A significant hematoma occurred in 23 patients, requiring reoperation in three patients. No patient died, developed infection, or stroke. The initial bridging regimen included LMWH (enoxaparin 1 mg/kg BID) given until evening prior to surgery, and reinitiated on postoperative day 3. In response to high rates of postoperative hematoma, subsequent protocols omitted the LMWH on the evening before surgery, all postoperative LMWH, or both. The use of LMWH the night before surgery had no effect on hematoma rates (12% vs 17%, P = 0.62); however, the use of any postoperative LMWH increased hematoma rates (23% vs 8%, P = 0.01). Hematoma rates were not increased in patients receiving acetylsalicylic acid (19% vs 16%, P = 0.62) or clopidogrel (25% vs 17%, P = 0.54). In a multivariate analysis, independent predictors of significant wound hematoma included postoperative LMWH (P = 0.001), a higher international normalized ratio on the day of surgery (P = 0.03), and male sex (P = 0.05). Conclusion: Elimination of postoperative LMWH was associated with a substantial reduction in hematoma rates following PM and ICD surgery. (PACE 2009; 32:378-382).