(RxWiki News) One common effect of atrial fibrillation is the buildup of scarring in parts of the heart. A new study looked at how a special MRI might evaluate that scarring to help determine the best treatment.
Researchers looked at delayed enhancement-magnetic resonance imaging (DE-MRI) to identify which atrial fibrillation (A-fib) patients benefitted most from catheter ablation.
Catheter ablation is a procedure in which a catheter burns away heart tissue responsible for the erratic signals.
The researchers said that the DE-MRI showed the amount of scarring found on the walls of the left atrium, allowing doctors to more easily recognize when the accumulation of scarring had reached a point where catheter ablation was no longer the most effective treatment.
"Discuss options for treating your A-fib with a doctor."
This study was led by Nassir Marrouche, MD, of the University of Utah School of Medicine.
The researchers followed 260 A-fib patients from the United States, Europe and Australia. Each patient was treated with catheter ablation surgery within 30 days of undergoing a new type of imaging test, called DE-MRI, of the left atrium.
Each patient in the study received regular follow up for 475 days after receiving the catheter ablation surgery.
The researchers looked at the data from the DE-MRIs, which are capable of revealing the amount of scarring in the left atrium, one of the upper chambers of the heart.
The patients scarring was rated between Stage 1, where less than 10 percent of the atrial wall contained scarring, up to Stage 4 where 30 percent of the atrial wall is covered with scarring.
The research team found that 85 percent of patents whose scarring was rated at least Stage 1 had no additional arrhythmias during the 475 day follow up. The rates dropped to 64 percent for stage 2 patients, 54 percent for Stage 3 patients and finally 31 percent of the stage 4 patients had no further arrhythmias during the follow up period.
The authors noted that catheter ablation does not work for all patients and there has not been a reliable way to predict which ones will benefit.
“Catheter ablation is a very effective treatment for atrial fibrillation, but it can’t cure everyone,” said study co-author David Wilber, MD, director of Loyola’s Division of Cardiology and Section of Clinical Electrophysiology.
“The findings from this study suggest there may be patients whose scarring is so advanced that ablation in its current form is much less likely to be effective as a single procedure. In such cases, patients, in consultation with their physicians, may decide to forgo ablation, or be prepared to have more than one procedure to control the arrhythmia,” Dr. Wilber said.
The researchers also said that the study suggests that treating A-fib earlier may be beneficial, since the longer a patient experiences A-fib, the more scarring the patient is likely to have.
The authors stated that prior to this study there had been no research into the clinical value of using DE-MRIs to assist in identifying patients who are good candidates for undergoing a catheter ablation procedure. Current methods of identifying good candidates for the procedure are limited.
The research authors noted that the study data was limited by the quality of images available due to hardware limitations and technical error.
This study was published February 4 in the JAMA.
The Comprehensive Arrhythmia and Research Management Center (CARMA) Center at the University of Utah provided funding for the study.
Dr. Marrouche reported owning stock and being named in 2 patents licensed to Marrek.
