MRI guided Fibrosis Ablation with PVI no better than PVI alone in refractory AF: Study
According to a recent study, researchers have found that PVI alone is more effective than a pragmatic ablation approach targeting CMR-detected atrial fibrosis plus PVI in an unselected population undergoing AF ablation with low fibrosis burden.
The study is published in Circulation: Arrhythmia and Electrophysiology Journal.
Myocardial fibrosis is considered a vital key for the maintenance of atrial fibrillation (AF). Therefore, Felipe Bisbal and colleagues from the Heart Institute at the University Hospital Germans, Madrid, Spain conducted the present study which basically aimed to test the efficacy of ablating cardiac magnetic resonance (CMR)-detected atrial fibrosis plus pulmonary vein isolation (PVI).
The study model was an open label, parallel-group, randomized, controlled trial where the patients were randomized on a 1:1 basis into 2 groups- PVI plus CMR-guided fibrosis ablation (CMR group) or PVI alone (PVI-alone group).
All the individuals selected for the research were undergoing first or repeat ablation with symptomatic drug-refractory AF (paroxysmal and persistent). The primary endpoint was the rate of recurrence (>30 seconds) at 12 months of follow-up using a 12-lead ECG and Holter monitoring at 3, 6, and 12 months. The analysis was conducted by intention-to-treat, the authors mentioned.
Out of the total sample of 155 patients, 76 individuals were allocated to the PVI-alone group whereas the CMR group had 79 patients. The first ablation was performed in 80% and 71% of patients in the PVI-alone and CMR groups, respectively.
The key results of the study were-
a. The mean atrial fibrosis burden was 12% (only 〜50% of patients had fibrosis outside the pulmonary vein area).
b. 100% and 99% of patients received the assigned intervention in the PVI-alone and CMR group, respectively.
c. The primary outcome was achieved in 21 patients (27.6%) in the PVI-alone group and 22 patients (27.8%) in the CMR group (odds ratio [OR]: 1.01, 95% confidence interval [CI] 0.50-2.04; p=0.976).
d. There were no differences in the rate of adverse events (3 in the CMR group and 2 in the PVI-alone group; p=0.68).
"A pragmatic ablation approach targeting CMR-detected atrial fibrosis plus PVI was not more effective than PVI alone in an unselected population undergoing AF ablation with low fibrosis burden", the authors concluded.
These findings suggest that there is no benefit to using PVI with ablation of CMR-detected atrial fibrosis rather than PVI alone, but the authors note that ablation of CMR-detected atrial fibrosis may be beneficial in selected populations of patients with a higher fibrosis burden.
For further reference, log on to https://doi.org/10.1161/CIRCEP.120.008707
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