ADVICE: Adenosine-Guided PVI Ablation Reduces Atrial Tachyarrhythmia Recurrence

June 24, 2014

NICE, FRANCE — The use of adenosine to identify and eliminate dormant pulmonary vein conduction during radiofrequency ablation of paroxysmal atrial fibrillation (AF) significantly reduces recurrent atrial tachyarrhythmias, according to the results of a large, prospective, multicenter trial.

Investigators, led by Dr Laurent Macle (Montreal Heart Institute, QC), report that adenosine helped "unmask" dormant electrical pathways following pulmonary vein isolation (PVI) during catheter ablation, and doing so led to additional ablation that reduced atrial tachyarrhythmias by more than 50%. It also significantly reduced the need for a repeat ablation procedure.

The Adenosine Following Pulmonary Vein Isolation to Target Dormant Conduction Elimination (ADVICE) trial was presented here at CardioStim 2014 . The study was performed at 11 centers in Canada, six in Europe, and one in Australia. In total, 546 patients with drug-refractory AF underwent PVI catheter ablation. Of these, 534 received intravenous adenosine 20 minutes after PVI to determine whether dormant PV conduction remained.

"Although AF ablation is superior to antiarrhythmic drugs in randomized clinical trials, AF recurs in up to 50% after ablation," Laurent told heartwire . "The majority of AF recurrences after AF ablation are due to reconnection of pulmonary veins. Adenosine may be used during the AF ablation procedure to detect pulmonary veins at risk of later reconnection, the so-called dormant pulmonary vein conduction. However, no prospective randomized clinical trial has evaluated this."

Of the 534 patients who received adenosine during the 20-minute period, 284 patients were identified as having dormant PV-conduction pathways. Of these, 147 were then randomized to further ablation of the PV pathway and 137 received no additional ablation. For the 250 patients without dormant PV conduction, 133 were randomized to routine medical care following the ablation and 117 were enrolled in a follow-up registry.

Regarding the primary end point—the time to first recurrence of symptomatic ECG-documented atrial fibrillation/atrial flutter/atrial tachycardia >30 seconds between three months and one year postablation—69.4% who had a dormant PV conduction and underwent additional targeted ablation were free from the symptomatic atrial tachyarrhythmia after a single ablation procedure. Comparatively, 42.3% of those with identified dormant conduction but who received no further ablation were free from the primary end point after a single ablation procedure. Of the 117 patients without dormant PV conduction included in a registry, 55.7% were free from atrial tachyarrhythmias at one year.

In terms of freedom from asymptomatic and symptomatic atrial tachycardia, those who received additional ablation of the dormant PV pathway had a 53% reduction compared with those who did not undergo additional ablation. Similar reductions were observed when the analysis was restricted to patients not taking antiarrhythmic drug therapy.

For those who underwent additional targeted ablation when the dormant conduction pathway was identified, 20.4% underwent a repeat ablation during the one-year follow-up. For those with dormant conduction not receiving further ablation, 35.0% required a repeat ablation for recurrent atrial tachyarrhythmias (p=0.006). Among the registry patients without any adenosine-identified dormant conduction, 27.4% required a repeat ablation at one year.

"If a routine strategy of adenosine testing is used with elimination of dormant conduction when present, which it is in about half of the patients, the overall effect is an absolute increase in success rates of 14%," Laurent told heartwire . The only downside to using adenosine, he added, was that use increased procedural times by 27 minutes. There was no difference in the complication rates among those undergoing adenosine-guided ablation of identified pathways.

The total follow-up included 401 patients, including the 117 patients without any adenosine-identified dormant conduction pathways. The overall rate of serious adverse events, which included in-hospital and follow-up, was 7.2%. There was no significant difference in adverse-event rates in those undergoing additional ablation, those who did not, and those without any identified dormant PV-conduction pathways.

The Canadian Institutes of Health Research funded the ADVICE trial. Additional support was provided by unrestricted grants from St Jude Medical and Biosense-Webster.



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