Does Periprocedural Anticoagulation Management of Atrial Fibrillation Affect the Prevalence of Silent Thromboembolic Lesion Detection by Diffusion Cerebral Magnetic Resonance Imaging in Patients Undergoing Radiofrequency Atrial Fibrillation Ablation With Open Irrigated Catheters? Results From a Prospective Multicenter Study

Study Questions:

Is the risk of silent cerebral ischemia (SCI) affected by the degree of anticoagulation during radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF)?


RFCA of AF was performed using a 3.5-mm irrigated-tip ablation catheter in three study groups: 1) uninterrupted warfarin and 8,000-10,000 unit bolus of heparin prior to transseptal catheterization (n = 146); 2) uninterrupted warfarin but failure to maintain therapeutic international normalized ratio (INR) prior to RFCA and/or no heparin administered prior to transseptal catheterization (n = 134); and 3) interrupted warfarin and heparin bridging (n = 148). Whether or not warfarin was interrupted was at the operators’ discretion. SCI was detected by cerebral diffusion magnetic resonance imaging pre- and within 48 hours post-ablation.


There was evidence of SCI preablation in 42-44% of patients in the three study groups, with no significant difference among the groups. Evidence of new SCI post-ablation was significantly more prevalent in group 3 patients (14%) than in group 1 (2%) or group 2 (7%) patients. The strongest independent predictor of SCI was a subtherapeutic INR (odds ratio, 2.8).


The authors concluded that therapeutic anticoagulation at the time of RFCA of AF greatly reduces the risk of SCI.


Prior studies have demonstrated that the risk of bleeding complications and stroke is lower in patients undergoing RFCA of AF if the INR is 2-3 on the day of the procedure than if warfarin is interrupted and heparin bridging is used. This study provides additional support for not interrupting therapy with warfarin in patients undergoing RFCA of AF.

Clinical Topics: Anticoagulation Management, Noninvasive Imaging, Magnetic Resonance Imaging

Keywords: International Normalized Ratio, Odds Ratio, Stroke, Warfarin, Catheterization, Heparin, Diffusion Magnetic Resonance Imaging

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