MRI-Guided Fibrosis Ablation vs. Conventional Ablation in Arrhythmia Recurrence

Quick Takes

  • In this randomized clinical trial that included 843 patients with persistent atrial fibrillation (AF), there was no significant difference in atrial arrhythmia recurrence in the MRI-guided fibrosis ablation group compared with the pulmonary vein isolation only group.
  • The results of this randomized trial do not support the use of MRI-guided fibrosis ablation for the treatment of persistent atrial fibrillation (AF).

Study Questions:

What is the efficacy and what are the adverse events of targeting atrial fibrosis detected on magnetic resonance imaging (MRI) in reducing atrial arrhythmia recurrence in patients with persistent atrial fibrillation (AF) undergoing catheter ablation?


DECAAF II, a multicenter randomized clinical trial, enrolled patients with symptomatic or asymptomatic persistent AF undergoing AF ablation. Patients with persistent AF were randomly assigned to pulmonary vein isolation (PVI) plus MRI-guided atrial fibrosis ablation or PVI alone. Delayed-enhancement MRI was performed in both groups before the ablation procedure to assess baseline atrial fibrosis and at 3 months post-ablation to assess for ablation scar.


Among 843 patients who were randomized, 815 completed the 90-day blanking period and contributed to the efficacy analyses. There was no significant difference in atrial arrhythmia recurrence between fibrosis-guided ablation plus PVI patients (43%) versus PVI-only patients (46%). Patients in the fibrosis-guided ablation plus PVI group experienced a significantly higher rate of safety outcomes (2.2% vs. 0 in PVI group). Six patients (1.5%) in the fibrosis-guided ablation plus PVI group had an ischemic stroke compared with none in PVI-only group. Two deaths occurred in the fibrosis-guided ablation plus PVI group, and the first one was possibly related to the procedure.


Among patients with persistent AF, MRI-guided fibrosis ablation plus PVI, compared with PVI catheter ablation only, resulted in no significant difference in atrial arrhythmia recurrence.


PVI is a cornerstone of catheter ablation in persistent AF. Various incremental strategies have been employed in order to enhance the efficacy of the ablation procedure with mixed results. These include adding a mitral line and/or left atrial roof line ablation, as well as ablating complex fractionated atrial and atrial rotors, or performing posterior wall ablation. The present study tested the hypothesis that ablation of the scar as demonstrated by MRI would improve time to recurrence of an atrial arrhythmia. This was predicated on prior findings that atrial fibrosis is a predictor of recurrence and may be seen on delayed-enhancement MRI. Unfortunately, the study found no benefit of the MRI-guided scar ablation as an adjunct to PVI. The results of this study are consistent with the much smaller recently published ALICIA randomized trial and many other well designed and implemented prospective randomized trials of anatomic ablation. The results may be related to inability to create homogenous transmural lesions, or it may be that there were other mechanisms of recurrence of AF.

Clinical Topics: Arrhythmias and Clinical EP, Noninvasive Imaging, Prevention, Implantable Devices, SCD/Ventricular Arrhythmias, Atrial Fibrillation/Supraventricular Arrhythmias, Magnetic Resonance Imaging

Keywords: Arrhythmias, Cardiac, Atrial Fibrillation, Catheter Ablation, Diagnostic Imaging, Fibrosis, Ischemic Stroke, Magnetic Resonance Imaging, Pulmonary Veins, Recurrence, Secondary Prevention

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