Device offers hope to heart patients

TAMPA, Fla. — Catharine DeMare never knew when it was going to strike — a racing heartbeat that would leave her weak, clammy and feeling like she was going to faint. The episodes would last for hours several times a week or more. Daily medications helped, but she wanted more — a cure — something she heard was possible with a new procedure using a device called the Arctic Front that freezes areas responsible for making the heart fibrillate.

The Food and Drug Administration approved the Medtronic device just before Christmas for patients who don't respond to drug therapy. In January at St. Joseph's Hospital in Tampa, DeMare became one of the first people in the nation to have the procedure outside a clinical trial. Mayo Clinic in Rochester, Minn., was the site of the first.

“I'm so excited about this,” the 65-year-old Tampa resident said from her hospital bed before Dr. James Irwin performed the procedure. “It just has so much promise.”

DeMare suffers from a common heart disorder called atrial fibrillation. It causes the atria, the upper chambers of the heart, to quiver erratically rather than beat rhythmically. When that happens, blood flow to the lower chambers is affected, so blood pools in the upper heart, causing weakness, shortness of breath and, at its most severe, blood clots that may cause a stroke.

According to the American Heart Association, atrial fibrillation affects more than 2 million Americans, mostly the elderly. The most common cause is high blood pressure; the second is having a history of rheumatic fever. DeMare's only risk factor was her age.

“As you get older, A-fib becomes more and more common,” Irwin said.

DeMare has had the condition for about six years. “It was frustrating every time she had it,'' her husband, Bill, 66, said. “It literally wipes you out.”

More recently, the disturbing episodes were occurring daily, despite medication prescribed to normalize her heart rhythm. She also took the potent blood thinner Coumadin to prevent clots. When DeMare heard that a new device was in clinical trials that could stop the irregular heartbeats and get her off the medications, she knew she wanted the procedure as soon as possible.

Irwin, a cardiologist who specializes in electrophysiology, correcting electrical problems in the heart, was involved in clinical trials for Arctic Front, using it on about 50 patients over the past five years. After DeMare, he has more than 200 people, one from Israel, on a waiting list for the procedure.

Arctic Front uses a tiny balloon that is threaded up to the heart in a catheter inserted through a vein in the leg. Once in the pulmonary vein, the balloon is inflated and cooled to minus 90 degrees Celsius — or minus 130 degrees F.

All cells that come in contact with the balloon are killed, wiping out cells responsible for the irregular heart rhythm. Other A-fib treatment devices use heat or cold to damage the area in certain spots, but they can't cover all the area that the balloon covers.

“They leave gaps, untreated areas, so people can still have A-fib after treatment,” Irwin said. “With this, we get full ablation of all the cells without leaving gaps.”

Spot treatment has about a 44 percent success rate; in clinical trials at the four busiest U.S. test sites, including St. Joseph's, Arctic Front had a 90 percent success rate, defined as no episodes of atrial fibrillation in the 90 days after the procedure, Irwin said. The success rate at all trial sites combined was 70 percent.

Irwin called the treatment a cure for most patients with paroxysmal atrial fibrillation, in which episodes last anywhere from minutes to days, and stop on their own.

The procedure should be more widely available as word gets to patients and more physicians learn to use the device.

Meanwhile, patients should proceed with caution, said cardiologist Dany Sayad, with Florida Cardiovascular Institute.

“Patients will hear about it and it will sound sexy and eventually everyone will offer it,” he said. But, he noted, the success of the procedure depends greatly on the practitioner's skill, as “the learning curve is steeper with this device than with others.” For instance, there is some risk of damaging a nerve next to the pulmonary vein, which can result in breathing problems.

A Medtronic spokeswoman said the cost of the procedure will average 10 percent to 15 percent higher than other cardiac ablation procedures, which run $9,000 to $15,000. It is covered by Medicare.

DeMare's procedure lasted three hours; she was able to speak with Irwin and her husband several hours later.

“I've been waiting for this day to finally get rid of A-fib,” she told the doctor in the recovery room. She spent one night in the hospital. If all goes as expected, Irwin says DeMare will be off all medications associated with the rhythm disorder within three months.

A day later, she said she was just a bit tired but doing all her normal activities.