Author + information
- Bradley P. Knight, MD⁎ ()
- ↵⁎Reprint requests and correspondence:
Dr. Bradley P. Knight, Bluhm Cardiovascular Institute of Northwestern, Feinberg School of Medicine, Northwestern University, 251 East Huron Street, Feinberg 8-503E, Chicago, Illinois 60611
- atrial fibrillation ablation
- matched case-control study
- periprocedural complications
Regardless of the approach to perioperative anticoagulation used, patients need to have a normal or nearly normal state of coagulation during surgery, so some increase in the risk of thromboembolism is unavoidable.—Kearon and Hirsh, 1997 (1)
Catheter ablation procedures are increasingly being performed for patients with medically refractory, symptomatic atrial fibrillation (AF). Because these procedures involve ablation in the systemic circulation and often conversion from AF to sinus rhythm, they are associated with a significant risk of thromboembolism. Therefore, many strategies are used during an ablation procedure to reduce the risk of stroke, including the use of intracardiac echocardiography, irrigated ablation electrodes, and aggressive anticoagulation (2).
In addition, several anticoagulation strategies have emerged to manage patients before and immediately after an ablation procedure for AF (Tables 1 and 2).⇓ When AF ablation began, it was standard practice to interrupt warfarin and “bridge” patients with low molecular weight heparin (LMWH) (Option #1 in Tables 1 and 2). Unfortunately, this approach was associated with a high rate of vascular access site complications. Most centers switched to half-dose LMWH and saw less bleeding, without a higher risk of stroke (Option #2 in Tables 1 and 2). The LMWH can be given soon after sheaths are pulled or held until the next morning while the patient is given intravenous unfractionated heparin. Regardless of the dose, however, administration of LMWH is costly, unpleasant for many patients, and often not covered by insurance companies.
The notion that patients need to have normal coagulation properties to undergo invasive procedures (1) has been challenged recently. It has now been demonstrated that several cardiac procedures, including device implantation (3) and coronary interventions (4), can be performed safely without interruption of warfarin, an approach that may be preferable to bridging with LMWH. In addition, left atrial ablation has been shown to be safe when performed in patients taking therapeutic warfarin, at experienced centers (Option #3 in Tables 1 and 2). In a series of 2,600 patients with AF who underwent ablation on warfarin, Di Biase et al. (5) found in 2010 that the combination of an open irrigation ablation catheter and periprocedural therapeutic anticoagulation with warfarin was associated with no strokes or transient ischemic attacks, without an increase in the risk of pericardial effusion or other bleeding complications. Further evidence that such an approach is safe came from a study by Latchamsetty et al. (6) that showed that if pericardial tamponade did occur, it was not more severe or difficult to manage in the presence of therapeutic anticoagulation with warfarin.
Despite clear demonstration that catheter ablation can be performed safely without stopping warfarin, this approach has not been adopted by all centers. Electrophysiologists who work at low-volume centers or who are just beginning to perform AF ablation are understandably cautious and concerned that if a catastrophic complication were to occur, it could be more life-threatening when the patient is anticoagulated with warfarin. There is also a concern that a practice that deviates from the conventional practices followed for most other surgeries and procedures would be difficult to defend if a complication were to occur. Therefore, there has been an interest in taking advantage of the benefits of the newer, shorter acting oral anticoagulants such as dabigatran, a direct thrombin inhibitor, around the time of catheter ablation for AF.
In this issue of the Journal, Lakkireddy et al. (7) compared the bleeding and stroke rates in patients undergoing AF ablation while on uninterrupted warfarin with those patients managed periprocedurally with dabigatran (Option #3 vs. Option #4 in Table 2). The investigators found a higher incidence of bleeding and pericardial effusions in patients treated with dabigatran and no difference in the rate of thromboembolism compared with warfarin.
At first this paper appears to suggest that dabigatran has no role periprocedurally in patients undergoing AF ablation. In fact, many physicians who participated in this study now convert their patients who are taking dabigatran to warfarin before an AF ablation procedure. However, it is important to note that dabigatran may still have a role around the time of an AF ablation. In the study by Lakkireddy et al., dabigatran was not stopped until the morning of the procedure and was restarted 3 h after sheaths were pulled. Given that the half-life of dabigatran is 14 to 17 h, this protocol is nearly equivalent to performing the procedure with the patient on uninterrupted dabigatran. Although there is arguably no standard of care on how to manage dabigatran around the time of an ablation procedure, as Lakkireddy et al. (7) acknowledge, the half-life of the drug is long enough that the recommendations of the manufacturer are to stop it at least 1 to 2 days before invasive or surgical procedures in patients with normal renal function and to consider longer times when complete hemostasis may be required.
Alternative anticoagulation approaches that might still take advantage of the benefits of dabigatran compared with warfarin would be to hold the dabigatran for 1 to 2 days before the ablation, give intravenous heparin during and after the procedure, and resume the dabigatran the following morning (Option #5 in Tables 1 and 2). A recent nonrandomized study by Winkle et al. (8) found no preprocedural or intraprocedural thromboembolic episodes or bleeding in 34 patients who were managed periprocedurally with dabigatran. In the Winkle et al. (8) study, dabigatran was held for 36 h before the procedure, half-dose LMWH was given after the procedure, and dabigatran was restarted 22 h after the procedure. It might also be reasonable to use half the usual dose of dabigatran (or the 110-mg dose where it is available), extrapolating from the lessons learned regarding the benefits of lower doses of LMWH post-procedure (Option #6 in Tables 1 and 2). Other options include using newer oral anticoagulants other than dabigatran, such as rivaroxaban (9), a direct Xa inhibitor (Option #7 in Tables 1 and 2). Rivaroxaban was recently approved for use for AF, has a shorter half-life than dabigatran, and appears to be reversible with prothrombin complex concentrates (10) if bleeding or tamponade were to occur.
Lakkireddy et al. (7) should be commended for pooling such a large number of patients from multiple centers to examine the role of dabigatran around the time of AF ablation. Based on their study, it appears that AF ablation should not be performed on nearly uninterrupted dabigatran, as it was used in this study. However, other approaches that capitalize on the advantages of the new oral anticoagulants must continue to be explored.
Dr. Knight has reported that he has no relationships relevant to the contents of this paper to disclose.
↵⁎ Editorials published in the Journal of the American College of Cardiology reflect the views of the authors and do not necessarily represent the views of JACC or the American College of Cardiology.
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