Ablation of Atrial Fibrillation Under Therapeutic Warfarin Reduces Periprocedural Complications: Evidence From a Meta-Analysis

Study Questions:

Is continuous warfarin therapy a clinically useful strategy during radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF)?

Methods:

This was a meta-analysis of nine studies in which either continuous warfarin (CW) (international normalized ratio [INR] 1.8-3.5) or interrupted warfarin (IW) with heparin bridging was used in a total of 27,402 patients undergoing RFCA of AF. These studies were prospective or retrospective observational studies and none were randomized. Thromboembolic and bleeding complications were compared between the two anticoagulation strategies.

Results:

The rate of thromboembolism was significantly lower in the CW group (0.06%) than in the IW group (0.94%). There was not a significant difference between the two groups in major bleeding complications and cardiac tamponade (0.55% with CW vs. 1.25% with IW). Minor bleeding complications occurred significantly less often in the CW group (4.5%) than in the IW group (18.6%).

Conclusions:

The rate of thromboembolism was significantly lower in the CW group (0.06%) than in the IW group (0.94%). There was not a significant difference between the two groups in major bleeding complications and cardiac tamponade (0.55% with CW vs. 1.25% with IW). Minor bleeding complications occurred significantly less often in the CW group (4.5%) than in the IW group (18.6%).

Perspective:

The meta-analysis confirms what individual, nonrandomized, observational studies have consistently reported, namely that continuous warfarin therapy improves the overall safety of RFCA of AF. A lingering concern of operators reluctant to adapt this strategy is that the extent of bleeding into the pericardial space might be greater if there is a left atrial perforation. However, a recent study (Heart Rhythm 2011;8:305-8) showed that the amount of pericardial drainage was similar across the range of subtherapeutic and therapeutic INRs in patients who developed cardiac tamponade during RFCA of AF.

Clinical Topics: Anticoagulation Management, Arrhythmias and Clinical EP, SCD/Ventricular Arrhythmias, Atrial Fibrillation/Supraventricular Arrhythmias

Keywords: Warfarin, Catheter Ablation


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