Elsevier

Heart Rhythm

Volume 6, Issue 10, October 2009, Pages 1425-1429
Heart Rhythm

Clinical
Ablation
Radiofrequency ablation of atrial fibrillation under therapeutic international normalized ratio: A safe and efficacious periprocedural anticoagulation strategy

https://doi.org/10.1016/j.hrthm.2009.07.007Get rights and content

Background

The best periprocedural anticoagulation strategy at the time of pulmonary vein isolation (PVI) is not known. Most centers stop administering warfarin (Coumadin) and use bridging with heparin or enoxaparin.

Objective

The purpose of this study was to evaluate the efficacy and safety of PVI under therapeutic international normalized ratio (INR).

Methods

Between January 2005 and December 2008, PVI was performed in 3,052 patients with therapeutic INR (≥1.8) at the time of ablation. All patients were evaluated for ischemic strokes and bleeding complications.

Results

Mean INR was 2.53 ± 0.62. Only 3 (0.098%) patients had ischemic strokes. One patient had a hemorrhagic stroke on the third day postablation but recovered completely by 1-week follow-up. Bleeding complications occurred in 34 (1.11%) patients; most were minor (0.79%). Major hemorrhagic complications occurred in 10 (0.33%) patients (tamponade in 5, hematomas requiring intervention in 2, transfusion necessary in 3).

Conclusion

In a large patient population, continuation of Coumadin at a therapeutic INR at the time of PVI without use of heparin or enoxaparin for bridging is a safe and efficacious periprocedural anticoagulation strategy. It is an acceptable and potentially better alternative to strategies that use bridging with heparin or enoxaparin.

Introduction

Radiofrequency ablation (RFA) has become an effective treatment of drug-refractory atrial fibrillation (AF). The risk of thromboembolic events at the time of the procedure remains a concern, and periprocedural anticoagulation to prevent these complications is of particular importance. However, anticoagulation may increase the risk of bleeding and hemorrhagic complications in the periprocedural period. The best anticoagulation procedure, which would minimize thromboembolism while not increasing hemorrhagic complications, is not known.

Different centers use various anticoagulation protocols at the time of RFA. Most centers discontinue warfarin (Coumadin) at least 3 to 5 days prior to ablation, start heparin or enoxaparin before the procedure, and use a “bridging” strategy to Coumadin after ablation.1, 2, 3 These strategies are consistent with recommendations made by the 2007 HRS/EHRA/ECAS expert consensus statement on catheter and surgical ablation of AF.4

Only a few centers initiate Coumadin prior to RFA and continue administering the drug during the procedure at a therapeutic level of international normalized ratio (INR). Operators who use this strategy believe that discontinuation of Coumadin prior to ablation may increase the risk of thromboembolic complications and that use of enoxaparin injections may be inconvenient as well as expensive for many patients. However, the 2007 HRS/EHRA/ECAS expert consensus statement expressed concerns that this strategy may increase the risk of acute bleeding complications.4

We previously reported that continuation of Coumadin throughout RFA without administration of heparin or enoxaparin is safe and efficacious5 and may be an alternative to strategies that use bridging. However, the safety of this strategy in a large patient population has not been reported.

The aim of our study was to evaluate the efficacy and safety of continuation of Coumadin at a therapeutic INR level without using enoxaparin or heparin for bridging as a periprocedural anticoagulation strategy in a large number of patients undergoing RFA for treatment of AF.

Section snippets

Methods

Between January 2005 and December 2008, all consecutive patients referred for AF ablation with INR ≥1.8 on the day of ablation were included in the study. All patients were evaluated for complications related to the procedure, at the time of ablation and at subsequent follow-up visits up to 4 months after PVI.

Complications were divided into two categories: hemorrhagic and thromboembolic. Major bleeding complications were defined as the occurrence of cardiac tamponade or hemopericardium that

Results

Between January 2005 and December 2008, 3,052 consecutive patients (1,400 from California Pacific Medical Center) were included in the study. The demographics and clinical characteristics of the patients are summarized in Table 1. One hundred fifty patients from our previous published experience were among this patient population. Mean INR on the day of the procedure was 2.53 ± 0.62.

The presenting rhythm to the electrophysiology laboratory was sinus rhythm in 1,642 (53.8%) patients, AF in 1,084

Cerebrovascular events

Ischemic stroke occurred in 3 (0.098%) patients. Stroke during the procedure was suspected. The procedure was terminated and the stroke team notified. Brain computed tomography angiograms confirmed the events. Two of the patients (both male, ages 53 and 63 years) had a left middle cerebral artery territory stroke, and 1 patient (male, age 61 years) had a right occipital stroke. Two of these patients presented to the electrophysiology laboratory in AF, and one presented in sinus rhythm. Their

Discussion

This is the largest series of patients in whom continuation of Coumadin at the time of RFA was evaluated. The occurrence of both thromboembolic events and hemorrhagic complications was very low with a mean INR 2.53 ± 0.62. Only 0.098% of patients undergoing RFA had ischemic cerebrovascular events, which were reversible in the majority of the patients. This anticoagulation strategy, while protecting patients undergoing RFA from thromboembolic complications, was not associated with a high

Study limitations

This was not a randomized study. However, the anticoagulation strategy described currently is the only approach to periprocedural anticoagulation used. Another limitation of this approach may be the perceived increased cost associated with ICE and ultrasound use; however, this may be offset by the decreased cost associated with not using low-molecular-weight heparin and the lower incidence of complications and their management. A formal cost analysis study may be warranted in the future. In

Clinical implications

Based on data from a patient population of more than 3,000 patients, continuation of Coumadin at a therapeutic INR level at the time of RFA without use of heparin or enoxaparin for bridging before or after ablation is a safe and efficacious periprocedural anticoagulation strategy. It is an acceptable and potentially better alternative to strategies that use bridging with heparin or enoxaparin.

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