Randomized Study of the Use of Warfarin During Pacemaker or ICD Implantation in Patients Requiring Long Term Anticoagulation
Condition: Bradycardia; Tachycardia; Atrial Fibrillation; Valvular Heart Disease
MeSH terms: Atrial Fibrillation; Heart Diseases; Tachycardia; Bradycardia; Heart Valve Diseases
Study type: Interventional

Summary: 
      Patients requiring long term anticoagulation often undergo transition of their warfarin to
      heparin in anticipation of invasive surgical procedures such as pacemaker or ICD
      implantation. This may require inpatient hospitalization several days prior to and after the
      procedure, potentially increasing medical costs and patient inconvenience. Patients
      undergoing such a process are initiated on heparin while their INRs drift to normal levels.
      Immediately prior to surgery, heparin is discontinued and restarted several hours after the
      procedure. Unfortunately, this process has resulted in a high incidence of surgical wound
      hematomas and other bleeding complications often requiring longer periods of discontinued
      anticoagulation or repeat surgical exploration. Previous investigators have tried to reduce
      the incidence of wound hematomas by prolonging the time from surgical wound closure to the
      reinitiation of heparin. A small randomized trial demonstrated that there was no significant
      difference in the incidence of wound hematomas whether heparin was started 6 hours or 24
      hours after surgery (J Am Coll Cardiology 2000;35:1915-8). This has led many investigators to
      perform pacemaker and ICD implantation without reversal of warfarin therapy. A recent
      retrospective observational study demonstrated that the incidence of wound hematomas in
      patients with an INR of 2.6 was no different than patients with an INR of 1.5 (PACE
      2004;27:358-60). Furthermore, a more recent, larger retrospective observational study
      reported in abstract form at the recent Heart Rhythm Society Annual 2007 Scientific Meeting
      demonstrated that not only is performing pacemaker and ICD implantations safe without
      reversing warfarin anticoagulation, but the incidence of wound hematomas is significantly
      smaller as compared to the strategy of reversing warfarin and initiating periprocedural
      heparin.

      Given these findings, the hypothesis of this randomized study is that pacemaker and ICD
      implantation while fully anticoagulated on warfarin therapy is safe. Findings from this study
      will have significant implications on the clinical practice of pacemaker or ICD implantation
      in this patient population given that no randomized study on this subject has been performed
      to date.
    


Intervention name(s): continue warfarin through the procedure; Hold warfarin; Warfarin held with heparin transition.
Intervention type(s): Drug; Drug; Drug
Intervention description(s): The usual dose of warfarin (resulting in a therapeutic INR) is taken throughout the peri-procedural period.; For moderate risk patients, warfarin will be held for 4-5 days prior to the procedure.; For high risk patients, warfarin is held for 4-5 days prior to the procedure and heparin is given to provide anticoagulation while the INR is subtherapeutic.
Intervention MeSH terms: Heparin; Warfarin
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Prevention
Keywords: bleeding; anticoagulation; pacemaker; implantable cardioverter-defibrillator; patients undergoing implantation of a pacemaker or defibrillator (ICD)"