Peri-Procedural Management of Novel Oral Anticoagulants in Catheter Ablation of Atrial Fibrillation
A 73-year-old man with persistent atrial fibrillation (AF), hypertension, and heart failure is seen for consideration of AF catheter ablation. He has no other significant past history. He is felt to have a reduced ejection fraction due to tachycardia-induced cardiomyopathy. Attempts at a rate control strategy were unsuccessful, with ongoing symptoms of exertional dyspnea. Attempts at amiodarone-facilitated electrical cardioversion were transiently successful with resolution of symptoms during sinus rhythm.
He is anticoagulated with dabigatran 150 mg by mouth twice daily due to patient preference. He is due to undergo AF catheter ablation in two weeks. His creatinine is 0.9 mg/dL with an estimated creatinine clearance of 97 mL/min.
What is the best strategy for peri-procedural anticoagulation for AF catheter ablation in this patient?
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The correct answer is: A. Hold dabigatran starting the evening prior to the procedure. Provide unfractionated heparin during the ablation procedure and resume dabigatran 4 hours after sheath removal.
The patient is appropriately on anticoagulation due to his CHADS2 score of 2 (heart failure and hypertension) and CHADS2VASc score of 3 (additional point for age >65 years old). As he remains in atrial flutter and has a significant risk for thromboembolism, it would be advised to keep him on anticoagulation until the time of the catheter ablation.
Anticoagulation is required during AF catheter ablation, as ablation in the systemic circulation increases the risk of thromboembolism which could result in arterial embolization. There is also a high likelihood that he will convert from atrial flutter to sinus rhythm during the ablation. Due to these risks with AF catheter ablation, it is recommended that prior to or immediately following the transeptal puncture heparin should be administered to maintain an activated clotting time (ACT) of at least 300-350 seconds (Answer B Incorrect).1 Ideally, procedural anticoagulation would be reversible given the risk for complications, such as cardiac perforation and tamponade, during catheter ablation.
Oral anticoagulant choices for patients with non-valvular AF have expanded in recent years, with FDA-approval of novel oral anticoagulants (NOACs) including a direct thrombin inhibitor (dabigatran) and two direct factor Xa inhibitors (rivaroxaban and apixaban). There are multiple reasonable peri-procedural anticoagulation options in a patient on dabigatran. Systemic reviews and meta-analyses have demonstrated that dabigatran can be continued until 12-24 hours before the procedure in a patient with normal renal function, bridged with unfractionated heparin during catheter ablation, and resumed approximately four hours after sheath removal without appreciable increase in thromboembolism or bleeding (Answer A CORRECT; Answer D Incorrect).2,3 A potential drawback to this strategy is lack of an efficacious reversal agent should a bleeding complication occur. It would be best to avoid the dose of dabigatran the night prior to the procedure as--in one study--this was associated with an increased risk of bleeding (Answer C Incorrect).4 In a patient with impaired renal function, consideration should be given to holding the dabigatran even earlier.
Some clinicians opt to switch from NOACs to Warfarin for uninterrupted use during catheter ablation in adjunct to unfractionated heparin during the procedure. This is a reasonable approach, as there is more robust data supporting the safety of catheter ablation on uninterrupted Warfarin.5,6 One study has shown that the optimal INR during uninterrupted Warfarin for AF catheter ablation is 2.1-2.5.7 While the anticoagulant effect of Warfarin is reversible, it can be inconvenient to switch to Warfarin and the INR may not be in a safe range the day of catheter ablation.
There are several unknowns regarding the use of NOACs peri-procedurally for AF catheter ablation. Dabigatran has been FDA approved the longest and has data demonstrating peri-procedural safety during AF catheter ablation.2,3 Less is known about the periprocedural safety of apixaban and rivaroxaban, although it has been reported that rivaroxaban has a greater degree of reversibility with prothrombin complex concentrates than dabigatran.8 A recent observational study did not find a difference in bleeding or thromboembolic events comparing patients with uninterrupted rivaroxaban (no skipped doses and with no procedural unfractionated or low-molecular weight heparin) versus warfarin (Answer E Incorrect). It is currently unknown if there is a difference in silent thromboembolic strokes between NOACs and Warfarin. Furthermore, the timing and amount of the last dose of NOACs before AF catheter ablation and the influence of renal function on this warrants further study.
After AF catheter ablation, anticoagulation should be continued for at least two months.1 Although not widely implemented, one group presented data that select patients with a CHADS2 score of 0 or 1 have a very low risk of thromboembolism if provided aspirin alone after AF catheter ablation.9 Thereafter, anticoagulation should be determined based on the patient’s risk of thromboembolism.
References
- Calkins H, Kuck KH, Cappato R, et al. 2012 HRS/EHRA/ECAS expert consensus statement on catheter and surgical ablation of atrial fibrillation: recommendations for patient selection, procedural techniques, patient management and follow-up, definitions, endpoints, and research trial design. Heart Rhythm 2012;9:632-96 e21.
- Bin Abdulhak AA, Khan AR, Tleyjeh IM, et al. Safety and efficacy of interrupted dabigatran for peri-procedural anticoagulation in catheter ablation of atrial fibrillation: a systematic review and meta-analysis. Europace 2013;15:1412-20.
- Providencia R, Albenque JP, Combes S, et al. Safety and efficacy of dabigatran versus warfarin in patients undergoing catheter ablation of atrial fibrillation: a systematic review and meta-analysis. Heart 2014;100:324-3.
- Lakkireddy D, Reddy YM, Di Biase L, et al. Feasibility and safety of dabigatran versus warfarin for periprocedural anticoagulation in patients undergoing radiofrequency ablation for atrial fibrillation: results from a multicenter prospective registry. J Am Coll Cardiol 2012;59:1168-74.
- Santangeli P, Di Biase L, Horton R, et al. Ablation of atrial fibrillation under therapeutic warfarin reduces periprocedural complications: evidence from a meta-analysis. Circ Arrhythm Electrophysiol 2012;5:302-11.
- Wazni OM, Beheiry S, Fahmy T, et al. Atrial fibrillation ablation in patients with therapeutic international normalized ratio: comparison of strategies of anticoagulation management in the periprocedural period. Circulation 2007;116:2531-4.
- Kim JS, Jongnarangsin K, Latchamsetty R, et al. The optimal range of international normalized ratio for radiofrequency catheter ablation of atrial fibrillation during therapeutic anticoagulation with warfarin. Circ Arrhythm Electrophysiol 2013;6:302-9.
- Eerenberg ES, Kamphuisen PW, Sijpkens MK, Meijers JC, Buller HR, Levi M. Reversal of rivaroxaban and dabigatran by prothrombin complex concentrate: a randomized, placebo-controlled, crossover study in healthy subjects. Circulation 2011;124:1573-9.
- Bunch TJ, Crandall BG, Weiss JP, et al. Warfarin is not needed in low-risk patients following atrial fibrillation ablation procedures. J Cardiovasc Electrophysiol 2009;20:988-93.