With a-fib, lots of options, ‘few clear answers’

Andrea Russo, an electrophysiologist at Cooper University Hospital in Camden, prepares a catheter for ablation. In ablation, sections of heart muscle that are sending errant electrical signals are isolated by scarring tissue with heat or cold.
Andrea Russo, an electrophysiologist at Cooper University Hospital in Camden, prepares a catheter for ablation. In ablation, sections of heart muscle that are sending errant electrical signals are isolated by scarring tissue with heat or cold. (Tony Fitts)
Posted: March 17, 2011

Eric Siegel is the kind of guy who can spend 45 minutes deciding which golf club to buy.

So it's not surprising that he'd want to know everything he could about atrial fibrillation, the irregular heartbeat that puts him at risk of stroke and more serious heart problems.

Every morning, the 54-year-old Bryn Mawr business-strategy consultant gets a Google alert tipping him to any new published material about his condition, which affects more than 2 million Americans.

He's been heartened to see how much research energy is being devoted to this vexing heart problem. New drugs and treatments have arrived.

But he's also glad that his own a-fib is under control with a relatively simple drug regimen - Rythmol, a drug for heart-rhythm problems, and aspirin to prevent strokes - because he hasn't seen a magic bullet.

"The next step won't be an obvious one," he said, when asked what he'll do next. A-fib typically gets worse and requires different treatments.

Area experts agree with Siegel that there's no cure and that it's hard to compare options.

"It's really a field with a lot of questions marks, a lot of individual opinions, a lot of biases, but very few clear answers," said S. Luke Kusmirek, director of the Drexel Atrial Arrhythmia Center at Hahnemann University Hospital.

"It forces you to swim in a sea of confusion, which is uncomfortable for a lot of patients."

Still, experts said, most a-fib patients are doing well. There have been significant improvements recently in drugs available to patients, and new knowledge and technology are improving ablation, the other major treatment option, as well.

In ablation, sections of heart muscle that are sending errant electrical signals are isolated by scarring tissue with heat or cold.

CABANA, a 3,000-patient study under way that compares drug therapy and ablation, should make decisions easier in a few years when its results are compiled, a-fib experts said. Doctors from Drexel, the University of Pennsylvania Health System, and Lankenau and Cooper University hospitals are participating.

The ventricles, or lower chambers, are the pumping workhorses of the heart, but electrical problems in the upper chambers - the atria - can cause them to quiver, or fibrillate, rapidly, disrupting the overall rhythm of the heart. This can make it pump less effectively.

Ultimately, that can lead to changes in the heart muscle that cause heart failure, but by far the biggest worry for people with atrial fibrillation is stroke. They are more likely than people without a-fib to have strokes, and the strokes they have are more serious, doctors said. "By the time we reach 80 years of age, one-third of all strokes that occur are because of atrial fibrillation," said Andrew Epstein, an electrophysiologist at the Hospital of the University of Pennsylvania.

No one knows why people get atrial fibrillation. It runs in some families, but that's not the dominant cause. It increases with age and often accompanies other conditions that can stress the heart: high blood pressure, diabetes, obesity, coronary artery disease, valve problems, heart failure and obstructive sleep apnea.

Some people with atrial fibrillation never feel it. Others, like Siegel, have undeniable symptoms. When he was first diagnosed in 2003, he could feel his heart beating irregularly and too fast. His medication seems to make those symptoms more subtle, but he sometimes gets dizzy and breathless.

While the minimizing of symptoms can greatly improve quality of life and is one of the goals of treatment, patients can be symptom-free and still have a stroke. "The stroke risk has nothing to do with symptoms," said Peter Kowey, chief of cardiology for Main Line Health. "One of the first manifestations of arrhythmia may be stroke."

So it's no surprise that preventing stroke is doctors' first priority. Their most important weapons are drugs that thin the blood. Siegel, who has a low stroke risk, takes aspirin, but the big gun in this sector since 1954 has been Coumadin, or warfarin. It's effective but difficult to take because it interacts with other medicines and foods, and requires frequent blood tests. "There's even cookbooks out there" for Coumadin-takers, said Daniel Frisch, director of the atrial-fibrillation program at Thomas Jefferson University Hospital.

At any time, only about two-thirds of patients are on the right dose of Coumadin, he said.

So it was huge news last year when Pradaxa, or dabigatran etexilate, the first new drug to rival Coumadin in more than 50 years, was approved by the U.S. Food and Drug Administration. Area a-fib experts said they're not rushing to switch patients who are doing well on Coumadin - Pradaxa is a lot more expensive, for one thing, and it's not covered by all insurers - but they're impressed with the results. Several other blood thinners are in the pipeline.

"Coumadin hasn't had a competitor since it was first introduced . . . so it's time," said Michael Ezekowitz, vice president of the Lankenau Institute for Medical Research. He was one of four leaders of the trial of Pradaxa, which involved 18,000 patients in 44 countries.

He said Pradaxa reduced stroke by 35 percent more than Coumadin and intracranial hemorrhage by an additional 60 percent to 70 percent. Ezekowitz, who said he has received funding from many drug companies, said Pradaxa has fewer drug interactions than Coumadin, starts working more quickly and doesn't require monitoring. On the downside, it is dosed according to kidney function and can cause gastrointestinal problems.

Multaq, or dronedarone, an antiarrhythmic drug that was approved in July 2009, is the other major medication news in a-fib. Experts said that it has potential as a good first-line drug but that they had concerns since the FDA issued an alert in January about rare, but severe, liver injury.

Doctors - and patients - are still hoping for a good alternative to amiodarone. It is the most effective antiarrhythmic but has major side effects.

On the ablation front, the FDA approved Medtronic's Arctic Front Cardiac CryoAblation Catheter system in December. It uses cold to isolate malfunctioning electrical signals near the pulmonary veins in the heart.

The procedure with the longest track record is radio-frequency ablation, which achieves the same goal with heat. Both techniques are performed through thin, flexible tubes called catheters. Experts said ablation has gotten better with more knowledge about where the signals that cause atrial fibrillation originate and how to block them more permanently and with rapidly evolving equipment.

Penn now uses a special breathing machine that immobilizes the lungs and has made a "dramatic difference," said Frank Marchlinski, director of the electrophysiology program. Of the operating room where he does ablations, he said, "it is truly like NASA in terms of the amount of equipment."

Ablation is now being used earlier in the disease process, although doctors say its risks are not to be taken lightly and it is usually reserved for patients who are disturbed by a-fib symptoms.

Andrea Russo, an electrophysiologist at Cooper, said the procedure, which has only been available since about 1999, is now appropriate for a broader array of patients with more serious rhythm problems.

Marchlinski said it's better than drugs, which he said fail about half the time. In studies of patients who already had tried one drug unsuccessfully, ablation got rid of symptoms in 75 percent while a second drug worked only 10 percent to 30 percent of the time, he said.

Still, symptoms often return in patients who've had ablation, and some may need a second trip to the OR. A recent French study found that only 30 percent were symptom-free after five years. Marchlinski said his five-year follow-up published last year found that about 30 percent of patients had recurrences.

The focus now is on making gains last longer.

One other approach being tested at Penn is to close off the left atrial appendage, a small, nonfunctioning pouch where 90 percent of the clots that cause strokes in a-fib form. Howard Herrmann, who runs catheterization labs at HUP, is involved in a trial of the Amplatzer Cardiac Plug.

"We're part of the first U.S. feasibility trial," Herrmann said. The plug is approved in Europe. An earlier trial of a different device proved generally positive, he said, but the FDA has asked for more testing.

St. Mary Medical Center is using a different approach that employs a device approved last year. The AtriClip system is used to close off the appendage during open-heart surgery.

The hope is that closing off the appendage will allow some patients to stop taking blood thinners.

Contact staff writer Stacey Burling at 215-854-4944 or sburling@phillynews.com.

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