Featured Research

from universities, journals, and other organizations

Magnetic resonance imaging before ablation for atrial fibrosis helps predict success of treatment

Date:
September 1, 2013
Source:
European Society of Cardiology
Summary:
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 new results.

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 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, MD, from the CARMA Center at the University of Utah in Salt Lake City, USA."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% which is really low, but if they're in an early stage their chance of cure is 60-80%," he said.

The DECAAF trial included 260 atrial fibrillation (AF) patients with atrial fibrosis who were undergoing ablation. The patients, from 15 centers in USA, Europe and Australia were a mean age of 59 years, and 64.6% 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%) 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 Dr. Marrouche.

Similarly, for every percentage of residual fibrosis there was an 8.2% 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 Dr. 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."


Story Source:

The above story is based on materials provided by European Society of Cardiology. Note: Materials may be edited for content and length.


Cite This Page:

European Society of Cardiology. "Magnetic resonance imaging before ablation for atrial fibrosis helps predict success of treatment." ScienceDaily. ScienceDaily, 1 September 2013. <www.sciencedaily.com/releases/2013/09/130901154151.htm>.
European Society of Cardiology. (2013, September 1). Magnetic resonance imaging before ablation for atrial fibrosis helps predict success of treatment. ScienceDaily. Retrieved July 23, 2014 from www.sciencedaily.com/releases/2013/09/130901154151.htm
European Society of Cardiology. "Magnetic resonance imaging before ablation for atrial fibrosis helps predict success of treatment." ScienceDaily. www.sciencedaily.com/releases/2013/09/130901154151.htm (accessed July 23, 2014).

Share This




More Health & Medicine News

Wednesday, July 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Courts Conflicted Over Healthcare Law

Courts Conflicted Over Healthcare Law

AP (July 22, 2014) Two federal appeals courts issued conflicting rulings Tuesday on the legality of the federally-run healthcare exchange that operates in 36 states. (July 22) Video provided by AP
Powered by NewsLook.com
Why Do People Believe We Only Use 10 Percent Of Our Brains?

Why Do People Believe We Only Use 10 Percent Of Our Brains?

Newsy (July 22, 2014) The new sci-fi thriller "Lucy" is making people question whether we really use all our brainpower. But, as scientists have insisted for years, we do. Video provided by Newsy
Powered by NewsLook.com
Scientists Find New Way To Make Human Platelets

Scientists Find New Way To Make Human Platelets

Newsy (July 22, 2014) Boston scientists have discovered a new way to create fully functioning human platelets using a bioreactor and human stem cells. Video provided by Newsy
Powered by NewsLook.com
Gilead's $1000-a-Pill Drug Could Cure Hep C in HIV-Positive People

Gilead's $1000-a-Pill Drug Could Cure Hep C in HIV-Positive People

TheStreet (July 21, 2014) New research shows Gilead Science's drug Sovaldi helps in curing hepatitis C in those who suffer from HIV. In a medical study, the combination of Gilead's Hep C drug with anti-viral drug Ribavirin cured 76% of HIV-positive patients suffering from the most common hepatitis C strain. Hepatitis C and related complications have been a top cause of death in HIV-positive patients. Typical medication used to treat the disease, including interferon proteins, tended to react badly with HIV drugs. However, Sovaldi's %1,000-a-pill price tag could limit the number of patients able to access the treatment. TheStreet's Keris Lahiff reports from New York. Video provided by TheStreet
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins