MRI-Guided Fibrosis Ablation Compared to Conventional Catheter Ablation

In the DECAAF II randomized controlled trial, researchers evaluated the safety and efficacy of using magnetic resonance imaging (MRI) detection to guide ablation of left atrial fibrosis in patients with persistent atrial fibrillation (AF). According to the primary investigator, Nassir F. Marrouche, “MRI-guided fibrosis ablation plus pulmonary vein isolation (PVI), compared with PVI catheter ablation only, resulted in no significant difference in atrial arrhythmia recurrence.”

The report, published in JAMA, described that the DECAAF II trial was a multicenter, investigator-initiated trial conducted at 44 academic and nonacademic facilities in 10 countries. The trial included a total of 843 patients with symptomatic or asymptomatic persistent AF who were undergoing ablation between July 2016 and January 2020. After randomization, 421 patients received PVI plus MRI-guided fibrosis ablation and 422 received PVI alone.

Researchers used delayed-enhancement MRI in all patients before ablation and at three months post-procedure. The primary outcome was the time to first atrial arrhythmia recurrence after a post-ablation blanking period of 90 days. Safety was evaluated as a composite of stroke, pulmonary vein stenosis, bleeding, heart failure, or death.

[H3] MRI-Guided Fibrosis Ablation Versus Contemporary Ablation Results

At the follow-up cutoff of February 19, 2021, 815 (96.9%) patients were eligible for the final efficacy analysis. According to the researchers, there was no significant difference in atrial arrhythmia recurrence between the two groups (study intervention: 175 [43%] vs. PVI-only: 188 [46.1%]; hazard ratio [HR], 0.95; 95% confidence interval [CI], 0.77-1.17; P=.63).

Based on the data, safety may have been worse with MRI-guided fibrosis ablation, as nine patients in the intervention group experienced a safety composite event compared to zero in the PVI-only group (P=.001). Additionally, six patients in the MRI-guided ablation group experienced ischemic stroke versus zero in the PVI alone group. The investigators also reported that two deaths occurred in the study group and noted the first death was “possibly” related to the procedure.

Ultimately, the authors found no advantages of the MRI-guided fibrosis ablation plus PVI combination compared to conventional ablation, and they concluded that their results “do not support the use of MRI-guided fibrosis ablation for the treatment of persistent AF.”

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