Cardiology Procedures

Thromboembolic Risks

Catheter ablation of atrial fibrillation is associated with the potential risk of periprocedural stroke, which can range between 1% and 5%.

Peri-procedural management of antiplatelet or anticoagulation therapy at the time of device implantation remains controversial.

Bleeding Risks

Use of heparin or LMWH in place of warfarin may not be advisable in device-based procedures. Implantations typically occur above the pectoral fascia and significant hematomas have been shown to occur in approximately 30% of patients managed with heparin bridging in these settings. 

Patients receiving heparin after cardiac device implantation had a 5- or 10-fold greater risk of pocket hematoma formation when compared with patients treated with warfarin alone or no anticoagulation, respectively.

General Recommendations for Pre-Procedure Warfarin Management

  • Cardioversion: Continue warfarin. Therapeutic INR required for 3 weeks prior to procedure (or perform TEE).
  • Radiofrequency ablation: Continue warfarin OR hold warfarin/bridge with LMWH (patient and provider specific decision)
  • Pacemaker and ICD placement: Continue warfarin
  • Pacemaker and ICD battery change: Continue warfarin
  • Angiogram/cardiac cath: Hold warfarin 3-4 days to target INR <1.5
  • Cardiothoracic surgery: Hold warfarin x5 days prior to surgery


Periprocedural stroke and management of major bleeding complications in patients undergoing catheter ablation of atrial fibrillation: the impact of periprocedural therapeutic international normalized ratio. Di Biase L, Circulation. 2010 Jun 15;121(23):2550-6.

Dual antiplatelet therapy and heparin "bridging" significantly increase the risk of bleeding complications after pacemaker or implantable cardioverter-defibrillator device implantation. Tompkins C, J Am Coll Cardiol. 2010 May 25;55(21):2376-82.

Continuing warfarin therapy is superior to interrupting warfarin with or without bridging anticoagulation therapy in patients undergoing pacemaker and defibrillator implantation. Ahmed I, Gertner E, Nelson WB, House CM, Dahiya R, Anderson CP, Benditt DG, Zhu DW. Heart Rhythm. 2010 Jun;7(6):745-9.

Continuation of warfarin during pacemaker or implantable cardioverter-defibrillator implantation: A randomized clinical trial. Cheng A, Heart Rhythm. 2010 Dec 13.


Special thanks to Ulrika Birgersdotter-Green, MD, Daniel Blanchard, MD and Sanjiv Narayan, MD for their expert guidance.