A 60-year-old man with past medical history of hypertension, coronary artery disease (CAD), congestive heart failure (CHF) with left ventricular ejection fraction (LVEF) of 25%, history of recurrent deep vein thrombosis (DVT) on chronic oral anticoagulation and atrial fibrillation (AF) was admitted for exacerbation of CHF. During hospitalization he had an episode of cardiac arrest. It was decided to place an automatic implantable cardioverter defibrillator (AICD) for secondary prevention.
Past medical history: Coronary artery disease, congestive heart failure, recurrent DVT, atrial fibrillation
Current medications: Aspirin, Simvastatin, Warfarin, Carvedilol
Physical exam:
General: Alert
Neck: Elevated Jugular venous pressure
Cardiac: irregularly irregular heart rate, S1, S2 heard
Chest: minimal crackles at the bases of the lungs
Extremities: 1+ pedal edema
What would be an appropriate strategy for management of periprocedural anticoagulation during placement of the AICD device so as to balance the risk of bleeding and thromboembolic complications?
Show Answer
The correct answer is: A. Continue warfarin therapy until 1 day before the procedure maintaining an INR between 2-2.5 on the day of procedure with no periprocedural heparin bridging and resumption of warfarin within 24 hours post procedure
Discussion
During the placement of an electrophysiologic device (EPD) in patients on chronic anticoagulation, the two important considerations in determining an appropriate periprocedure anticoagulation strategy are the risk; of thromboembolic (TE) and periprocedural bleeding complications.
As per the current guidelines (9th ed: American College of Chest Physicians evidence-based clinical practice Perioperative management of antithrombotic therapy: Antithrombotic Therapy and Prevention of Thrombosis), it is recommended to stop the oral anticoagulation therapy (OAC) and bridge with heparin around the time of the surgery.1 A disadvantage of this approach is increased incidence of device hematoma with prolonged hospital stay. Various trials have compared the risk associated with these anticoagulation strategies.
Studies evaluating periprocedural discontinuation of oral anticoagulation along with heparin bridging
When withholding the anticoagulant periprocedure, the risk of thromboembolic complications is significantly greater than the annual thromboembolic rate2. According to ACC/AHA consensus guidelines 20063, bridging anticoagulation with heparin is recommended for patients with high TE risk. Such patients include those with mechanical valves with additional risk factors such as atrial fibrillation, previous thromboembolism, left ventricular dysfunction, hypercoagulable conditions, more thrombogenic valves or more than one mechanical valve3. Heparin bridging in patients on chronic oral anticoagulation undergoing EPD placement has an increased risk of device pocket haematoma formation. With bridging therapy, Vincent etal4 reported 25-fold increase in haematoma formation after permanent pacemaker (PPM) implantation on resuming therapeutic anticoagulation with heparin as compared to holding anticoagulation.
Studies comparing heparin bridging vs continuation of OAC in high risk patients:
Jamula et al.5 reported the incidence of thromboembolic complications associated with both the strategies was similar. Bridging anticoagulation with therapeutic heparin was associated with higher risk for hematoma formation than, continuation of therapeutic warfarin around the time of procedure.5
BRUISECONTROL6, a multicentre, single- blind, randomized controlled trial evaluating outcomes, specifically in patients at high risk of thromboembolism undergoing EPD implantation, reported lower TE complications and bleeding risk in uninterrupted warfarin group than heparin bridging group. In a prospective randomized trial in high risk patients, Tolosana et al.7 recently demonstrated uninterrupted OAC with INR range 2.0±0.3 during device implantation has similar TE risk as bridging anticoagulation, while minimizing the bleeding complications with a significant reduction in length of hospital stay.
Above three studies, included high risk patients undergoing EPD placement and showed evidence of similar safety profile with considerably low risk in device hematoma and other bleeding complications in patients continued on warfarin vs heparin bridging.
Since the patient in the case study is at high risk for thromboembolic complications, he would have required heparin bridging according to the existing guidelines. However, based on recent studies, available data and institutional experience, it was decided to continue oral anticoagulation therapy maintaining INR in the range between 2- 2.5 on the day of surgery without bridging. Patient received a dose of warfarin on the morning before the day of surgery, with INR of 2.4 on the day of surgery. There were no intra-operative bleeding complications and oral anticoagulation was resumed on the evening of surgery. Post procedure, there were no thromboembolic complications with no evidence of significant device hematoma or bleeding complications.
From the above discussion it is clear that the decision for the peri-procedural anticoagulation strategy has to be individualized based on clinical scenario and the institution's experience. Hence, there is a need of further studies to characterize anticoagulation strategies with respect to specific clinical settings.
References
Douketis JD, Spyropoulos AC, Spencer FA, et al. Perioperative management of antithrombotic therapy: Antithrombotic therapy and prevention of thrombosis, 9th ed: American college of chest physicians evidence-based clinical practice guidelines. Chest 2012;141(2 Suppl):e326S-50S.
Nascimento T, Birnie DH, Healey JS, et al. Managing novel oral anticoagulants in patients with atrial fibrillation undergoing device surgery: Canadian survey. Can J Cardiol. 2014;30:231-236.
Bonow RO, Carabello BA, Chatterjee K, et al. 2008 focused update incorporated into the ACC/AHA 2006 guidelines for the management of patients with valvular heart disease: A report of the American college of Cardiology/American heart association task force on practice guidelines (writing committee to revise the 1998 guidelines for the management of patients with valvular heart disease). J Am Coll Cardiol 2008;52:e1-142.
Chow V, Ranasinghe I, Lau J, et al. Peri-procedural anticoagulation and the incidence of haematoma formation after permanent pacemaker implantation in the elderly. Heart Lung Circ 2010;19:706-712.
Jamula E, Douketis JD, Schulman S. Perioperative anticoagulation in patients having implantation of a cardiac pacemaker or defibrillator: A systematic review and practical management guide. J Thromb Haemost 2008;6:1615-1621.
Birnie DH, Healey JS, Wells GA, et al. Pacemaker or defibrillator surgery without interruption of anticoagulation. N Engl J Med 2013; 368:2084-2093.
Tolosana JM, Berne P, Mont L, et al. Preparation for pacemaker or implantable cardiac defibrillator implants in patients with high risk of thrombo-embolic events: Oral anticoagulation or bridging with intravenous heparin? A prospective randomized trial. Eur Heart J 2009;30:1880-1884.
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