USF Health Cardiovascular Sciences among Afib ablation leaders in DECAAF trial

MRI helps assess effect of atrial fibrosis on Afib ablation therapy outcome, multinational study reported in JAMA shows

A provocative study recently reported in the Journal of the American Medical Association demonstrated that delayed enhanced magnetic resonance imaging of the atrial chambers before ablation for atrial fibrillation (AF) can help predict the treatment’s success in restoring and maintaining normal heart rhythm.

The USF Health Morsani College of Medicine’s Department of Cardiovascular Sciences was a participant in the prospective one-year trial known as DECAAF, or Delayed Enhancement-MRI Catheter Ablation of Atrial Fibrillation, that followed 272 patients from 15 centers across the United States, Europe and Australia.

Bengt Herweg, MD, associate professor of medicine and director of the USF Health Electrophysiology and Arrhythmia Services, was a co-author of the promising study, which sheds new light on the mechanism of atrial fibrillation (AF) and may ultimately change the way ablation is performed.  Dr. Herweg performs ablation therapy for AF at Tampa General Hospital.

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Bengt Herweg, MD, leads the Electrophysiology and Arrhythmia Services at USF Health.

The DECAAF trial evaluated the relationship between atrial fibrosis, the amount of scarring on the walls of the heart’s left atrium, and the success of ablative therapy for atrial fibrillation, a technique that uses a catheter to burn critical tissue leading to abnormal heart rhythms, or arrhythmias.

Current methods for identifying which patients are good candidates for catheter ablation are limited.

“While the procedure can be a very effective treatment for atrial fibrillation, it does not control arrhythmias for all patients,” Dr. Herweg said. “This study indicated that delayed enhancement MRI imaging before ablation may be a reliable, noninvasive way to quantify atrial fibrosis and predict which patients will benefit.”

Among the study’s findings:

-          Hypertension was the only predictor of atrial fibrosis in patients with AF.

-          Increasing degrees of fibrosis, as estimated by delayed-enhanced MRI scans 30 days before atrial fibrillation ablation, were independently associated with a greater risk of AF recurring.

-          A comparison of post-ablation MRI images with pre-ablation images indicated a surprising finding.  Procedures targeting ablation of the fibrotic (scar) tissue rather than the standard method of isolating and ablating around the pulmonary veins, long assumed to be the trigger for AF, produced better outcomes.

“The feasibility of implementing delayed enhancement MRI screening to detect left atrial fibrosis into clinical practice could potentially improve patient selection for AF ablation and could translate into cost savings by avoiding unnecessary AF ablation procedures,” the researchers concluded.