Biomarker predicts success of Afib treatment

February 12, 2018, Johns Hopkins University

Johns Hopkins researchers report successful use of heart imaging to predict the benefit or futility of catheter ablation, an increasingly popular way to treat atrial fibrillation, a common heart rhythm disorder.

The researchers caution that a more randomized and controlled clinical trial is needed before doctors can reliably use their cardiac imaging analysis routinely with , but if confirmed, they say the method should reduce ablation procedures unlikely to work, along with the procedures' substantial costs and complication risks.

The investigators described their findings Jan. 17 in the Journal of the American College of Cardiology: Cardiovascular Imaging.

Atrial fibrillation, diagnosed in 3.4 million Americans and the most common heart rhythm condition in the United States, is marked by irregular and sometimes extremely rapid heart rates that cause fatigue and shortness of breath, and significantly increase the risk of heart failure and stroke. Treatments include drugs to regulate the electrical pulses in the upper chambers of the heart and ¾ increasingly ¾ . The procedure involves general anesthesia and imaging guided use of a wire catheter threaded through a vein to the heart to make scores of tiny burns of tissue in which the irregular heartbeats arise.

However, an estimated 20 to 30 percent of the ablation procedures performed each year fail to prevent irregular heart rhythms, and cardiologists have long sought various biological or anatomical factors to help them determine in advance which patients are the best candidates for ablation.

"In our study, we found that the best indicator of success is how in sync the left atrium chamber of the heart is when it relaxes," says Luisa Ciuffo, M.D., a postdoctoral fellow in the Division of Cardiology at the Johns Hopkins University School of Medicine. "Diseased, damaged hearts with a lot of scar tissue don't contract and relax at the same time throughout the atrium because it is more difficult to rhythmically contract the thicker, tougher damaged tissue."

For the study, designed to identify the best predictors, the researchers used data from 208 atrial fibrillation or "Afib" patients admitted to The Johns Hopkins Hospital to undergo ablation between June 2010 and December 2015.

Some 29 percent of the patients were women and the average age of all patients was 59. Prior to the ablation, each subject underwent computed tomography scans or MRIs of their hearts and were followed for an average of 20 months to assess recurrence of Afib, including a faster than normal heartbeat or an irregular heartbeat lasting longer than 30 seconds. Atrial fibrillation recurred in 101 patients.

The researchers then analyzed various characteristics of the imaging scans from 208 people in a subgroup: 107 of the people with successful ablations compared to 101 of those with failed ablations. The researchers investigated factors such as smallest and largest sizes of the left atria, the percentage of blood pushed out of the left atrium when the heart contracted and the amount of strain on the left atrium during heart contraction.

The analysis to determine the level of dys-synchrony in the left atrium took about nine minutes per case. Using the cardiac images, the atrium was divided up into 12 segments, and the researchers calculated the relaxation time in each of the segments and then compared them to each other. Those hearts that had the most differences between the segments of the atrium ¾ a higher deviation ¾ were considered the most dys-synchronous.

Overall, the Johns Hopkins researchers found that patients with recurrent atrial fibrillation had on average more preoperative dys-synchrony throughout the left atrium than those who had successful ablations (3.9 percent versus 2.2 percent), with the higher value indicating more diseased atrium.

In a second part of the research, the investigators took the scans from a group of 103 patients, both with successful and unsuccessful ablations, analyzed the percentage of atrial dys-synchrony in the and assigned them to one of two groups: one less than or another greater than 2.86 percent.

They expected those people with values lower than 2.86 percent to be better candidates for ablation because would be less likely to recur than in those people with more than the 2.86 percent cutoff. They then compared these groupings to their actual outcomes after ablation. They found that their model had a 76 percent sensitivity ¾ the ability to correctly identify those who were unlikely to have successful ablations ¾ and 81 percent specificity ¾ the ability to correctly identify those who would most likely have successful ablations.

"We believe we are developing a tool that can help with personalized decision-making to help refine patient selection and thus reduce the failure rate by saving candidates with low potential benefit from futile procedures and complications," says senior author Hiroshi Ashikaga, M.D., Ph.D., assistant professor of medicine at the Johns Hopkins University School of Medicine.

An ablation procedure isn't cheap, says Ciuffo, sometimes costing as much as a new car. The cost of cardiac imaging typically performed before the ablation procedure is a fraction of the cost of the procedure.

Although the risk of complication is small, about 6 percent with , there is still the chance of puncturing the or forming a fistula.

Explore further: Ablation better than medical Tx for A-fib with heart failure

More information: Luisa Ciuffo et al. Intra-Atrial Dyssynchrony During Sinus Rhythm Predicts Recurrence After the First Catheter Ablation for Atrial Fibrillation, JACC: Cardiovascular Imaging (2018). DOI: 10.1016/j.jcmg.2017.11.028

Related Stories

Ablation better than medical Tx for A-fib with heart failure

February 1, 2018
(HealthDay)—Among patients with atrial fibrillation and heart failure, catheter ablation is associated with a significant reduction in a composite end point of death from any cause or hospitalization for worsening heart ...

Catheter ablations reduce risks of stroke in heart patients with stroke history, study finds

November 13, 2016
Atrial fibrillation patients with a prior history of stroke who undergo catheter ablation to treat the abnormal heart rhythm lower their long-term risk of a recurrent stroke by 50 percent, according to new research from the ...

MRIs help predict which atrial fibrillation patients will benefit from catheter ablation

February 4, 2014
A new type of contrast MRI can predict which heart patients with atrial fibrillation are most likely to benefit from a treatment called catheter ablation, according to a landmark multi-center study published in the Journal ...

Study finds new markers associated with recurrence of AFib in previously treated patients

March 18, 2017
Ablation procedures restore a regular heartbeat in patients who have a dangerous, abnormal heart rhythm called atrial fibrillation. But it doesn't always work. Now, a new study suggests that certain molecules are associated ...

Ablation increases survival for adults with atrial fibrillation

July 30, 2014
Adults who undergo a minimally invasive technique to treat atrial fibrillation are significantly less likely to die from a heart attack or heart failure, according to a long-term study by the University of Michigan Frankel ...

Quantifying effectiveness of treatment for irregular heartbeat

July 17, 2017
In a small proof-of-concept study, researchers at Johns Hopkins report a complex mathematical method to measure electrical communications within the heart can successfully predict the effectiveness of catheter ablation, the ...

Recommended for you

Novel genetic study sheds new light on risk of heart attack

October 12, 2018
Loss of a protein that regulates mitochondrial function can greatly increase the risk of myocardial infarction (heart attack), Vanderbilt scientists reported Oct. 3 in the journal eLife.

Researchers say ritual for orthodox Jewish men may offer heart benefits

October 11, 2018
A pilot study led by researchers at the University of Cincinnati (UC) College of Medicine suggests Jewish men who practice wearing tefillin, which involves the tight wrapping of an arm with leather banding as part of daily ...

Markers of dairy fat consumption linked to lower risk of type two diabetes

October 10, 2018
Higher levels of biomarkers of dairy fat consumption are associated with a lower risk of developing type 2 diabetes, according to new research published today in PLOS Medicine. The study, in more than 60,000 adults, was undertaken ...

Seed oils are best for LDL cholesterol

October 9, 2018
If you want to lower your low-density lipoprotein cholesterol, called LDL or, colloquially, "bad cholesterol," the research is clear about one thing: You should exchange saturated fats with unsaturated fat. If you want to ...

Micropeptide restores heart function in mice

October 9, 2018
Researchers have discovered a micropeptide molecule that can restore normal heart function in mice, according to a study in eLife.

New risk test for sepsis for heart patients

October 5, 2018
Nearly one in four deaths in people with heart failure are caused by sepsis, according to new research.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.