News | September 10, 2013

MRI Before Ablation for Atrial Fibrosis Helps Predict Success of Treatment

Late-breaking trials on intervention and device

September 10, 2013 — In patients with atrial fibrillation, delayed enhancement magnetic resonance imaging (DE-MRI) performed before ablative treatment can stage the degree of damaged heart tissue (atrial fibrosis) and help predict whether treatment will be successful or not, according to results of the Delayed Enhancement — MRI determinant of successful Catheter Ablation of Atrial Fibrillation (DECAAF) trial.

"The DECAAF results show that stage of atrial fibrosis prior to ablation is a new, powerful, independent predictor of outcome," said lead investigator Nasir Marrouche, M.D., from the CARMA Center at the University of Utah in Salt Lake City.

"By performing this imaging before ablative treatment we can triage patients according to likelihood of treatment success, and avoid ablative procedures in those patients for whom it is unlikely to work. If a patient has late stage 3 or stage 4 fibrosis their chance of being cured is only 30-35 percent, which is really low, but if they're in an early stage their chance of cure is 60-80 percent," he said.

The DECAAF trial included 260 atrial fibrillation (AF) patients with atrial fibrosis who were undergoing ablation.

The patients, from 15 centers in the United States, Europe and Australia were a mean age of 59 years, and 64.6 percent of them had paroxysmal AF.

High resolution Delayed Enhancement MRI (DE?MRI) was performed up to 30 days before ablation in all patients to determine the presence and extent of atrial fibrosis, while post- ablation DE-MRI was performed at 90-days follow-up in 177 of the subjects, to determine the extent of residual ablation.

At the 90-day follow-up, recurrence of arrhythmia was noted in 88 of the 260 patients (33.8 percent) based on Holter monitors and electrocardiograms.

Multivariate analysis revealed two independent predictors of successful ablation or recurrent symptoms were stage of atrial fibrosis before ablation (P<0.001) as well as residual fibrosis after (P<0.001).

Specifically, patients whose pre-ablation fibrosis was stage 1 (defined as less than 10% damaged atrial tissue) had an 85.8% success rate, those with stage 2 (10% - 20% damage) had a 63.3% success rate, those with stage 3 (20% - 30% damage) had a 55% success rate and those with stage 4 (more than 30% damage) had a 31% success rate.

For every increased percentage of fibrosis before ablation, there was 6.3% increased risk of recurrent symptoms after ablation (hazard ratio [HR] 1.063), said Marrouche.

Similarly, for every percentage of residual fibrosis there was an 8.2 percent increased risk of recurrent symptoms (HR 1.082).

A secondary finding of the study, based on post-ablation imaging, showed that the type of ablation clinicians used also had an impact on success rates. The choice of procedure was not dictated in the study protocol and was left to the discretion of individual treating physicians.

After comparing pre-ablation images of fibrotic tissue, with post-ablation images showing the extent of residual fibrosis, a surprise finding was that pulmonary vein ablation, which is the standard-of-care in atrial fibrillation ablation candidates, is not the best ablative approach, said Marrouche.

"We do ablation around the pulmonary veins because we have assumed for years that the trigger for AF comes from the vein — that's the standard of care," he said. "But what we found in DECAAF is that ablation of the veins did not predict outcome. In fact, the most important predictor of outcome, along with stage of atrial fibrosis, was the degree of ablation of the fibrotic tissue. Rather than targeting the pulmonary veins, procedures which ablated fibrotic tissue produced better outcomes - the more that was targeted, the better the outcome."

For more information: europace.oxfordjournals.org/content/current

DISCLOSURES: Marrouche disclosed that he has received honoraria from: Biotronik, Siemens, Boston Scientific, and Boehringer Ingelheim; he has received consulting fees from: Sanofi and eCardio; he has received research grants from eCardio and estech; he has received equipment from Siemens; he has stock options with MRI-Intervetions; and holds stock in Marreck Inc.

Related Content

Imricor Announces Enrollment Completion for Clinical Study on Vision-MR Ablation Catheter
News | Interventional Radiology | January 23, 2018
January 23, 2018 – Imricor Medical Systems announced today the completion of enrollment for the...
Philips Introduces Technology Maximizer Program for Imaging Equipment Upgrades
Technology | Imaging | January 17, 2018
January 17, 2018 — Philips recently announced the launch of Technology Maximizer, a cross-modality program designed t
Russian Team Developing New Technology to Significantly Reduce MRI Research Costs
News | Magnetic Resonance Imaging (MRI) | January 16, 2018
January 16, 2018 — Researchers from the NUST MISIS Engineering Center for Industrial Technologies in Russia have deve
Transpara Deep Learning Software Matches Experienced Radiologists in Mammogram Reading
News | Computer-Aided Detection Software | January 12, 2018
Deep learning and artificial intelligence improves the efficiency and accuracy of reading mammograms, according to...
Smartphone Addiction Creates Imbalance in Brain
News | Mobile Devices | January 11, 2018
Researchers have found an imbalance in the brain chemistry of young people addicted to smartphones and the internet,...
Fat Distribution in Women and Men Provides Clues to Heart Attack Risk
News | Women's Health | January 11, 2018
January 11, 2018 – It’s not the amount of fat in your body but where it is stored that may increase your risk for hea
Minimally Invasive Treatment Provides Relief from Back Pain

Lumbar spine MRI showing disc herniation and nerve root at baseline and one month after treatment

News | Interventional Radiology | January 11, 2018
The majority of patients were pain free after receiving a new image-guided pulsed radiofrequency treatment for low back...
Emergency Radiologists See Inner Toll of Opioid Use Disorders

Rates of Imaging Positivity for IV-SUDs Complications. Image courtesy of Efren J. Flores, M.D.

News | Clinical Study | January 11, 2018
January 11, 2018 – Emergency radiologists are seeing a high prevalence of patients with complications related to opio
CT Shows Enlarged Aortas in Former Pro Football Players

3-D rendering from a cardiac CT dataset demonstrating mild dilation of the ascending aorta.

News | Computed Tomography (CT) | January 11, 2018
Former National Football League (NFL) players are more likely to have enlarged aortas, a condition that may put them at...
Study Finds No Evidence that Gadolinium Causes Neurologic Harm

MR images through, A, C, E, basal ganglia and, B, D, F, posterior fossa at level of dentate nucleus. Images are shown for, A, B, control group patient 4, and the, C, D, first and, E, F, last examinations performed in contrast group patient 13. Regions of interest used in quantification of signal intensity are shown as dashed lines for globus pallidus (green), thalamus (blue), dentate nucleus (yellow), and pons (red).

News | Contrast Media | January 11, 2018
January 11, 2018 — There is no evidence that accumulation in the brain of the element gadolinium speeds cognitive dec
Overlay Init