Assessing Arrhythmias After Ablation Using Implantable Recorders (ABACUS)

Assessment of Arrhythmia Burden in Patients Undergoing Atrial Fibrillation Using an Implantable Loop Recorder (ILR) Versus Conventional Monitoring Strategy

The purpose of this study is to determine if continuous monitoring using an implantable loop recorder (ie. a device that is placed just underneath the skin of the chest and monitors the heart rate and rhythm) for a year long period after atrial fibrillation ablation may be superior to the current conventional monitoring strategy used by us for determination of atrial fibrillation recurrence (ie. return of the abnormal heart rhythm) and/or arrythmia burden (ie. how long the abnormal rhythm continues or how often the rhythm occurs). Some data suggests that continuous monitoring over longer periods may be better in identifying recurrence of atrial fibrillation after ablation and thus assist in its overall management. The device being used for this study is the Reveal XT, which, is currently FDA approved for monitoring all varieties of cardiac rhythm disorders including atrial fibrillation.

Subjects will be monitored for 12 months using the conventional strategy which includes wearing a monitor over 3 separate 30-day periods over the first year post-ablation and daily pulse checks.

Subjects will be monitored using the conventional monitoring strategy for the first 6 months post-ablation. During the next 6 months, subjects will be monitored using the data from the Reveal device, transmitted from home every 30 days.

All study participants will receive the Reveal XT implantable loop recorder immediately after completion of the ablation procedure.

The primary outcome will be arrhythmia recurrences (atrial fibrillation and/or other atrial arrhythmias) after atrial fibrillation ablation over the initial 6 months and one year post-ablation as detected by the implantable loop recorder versus the conventional monitoring strategy. Months 1- 6 patients were being monitored by CM and ILR and in months 6 - 12 they were randomized to either ILR or CM.

Change of clinical care include initiation of previously discontinued and/or new anti-arrhythmic drugs, decision for repeat ablation, hospitalization for arrhythmias, discontinuation or reinitiation of atrio-ventricular nodal blocking agents, discontinuation or reinitiation af anticoagulation after ablation and/or decision to implant a pacemaker and/or defibrillator.

Inclusion Criteria: Greater than 18 years Undergoing ablation for atrial fibrillation at the University of Pennsylvania Exclusion Criteria: Patients with already implanted devices, including pacemakers, implantable cardiac defibrillators and cardiac resynchronization devices

Kapa S, Epstein AE, Callans DJ, Garcia FC, Lin D, Bala R, Riley MP, Hutchinson MD, Gerstenfeld EP, Tzou W, Marchlinski FE, Frankel DS, Cooper JM, Supple G, Deo R, Verdino RJ, Patel VV, Dixit S. Assessing arrhythmia burden after catheter ablation of atrial fibrillation using an implantable loop recorder: the ABACUS study. J Cardiovasc Electrophysiol. 2013 Aug;24(8):875-81. doi: 10.1111/jce.12141. Epub 2013 Apr 11.