Thursday, May 13, 2010

Freezing atrial fibrillation in its tracks

Cryoballoon ablation shows promise as new treatment for arrhythmia

Michael Walsh's heart was constantly racing; and the irregular heartbeat caused by a type of arrhythmia called atrial fibrillation (AF) was leading to physical discomfort and emotional distress.

"It's a panicked feeling when your heart starts to race," he said. “You don't know whether it's the arrhythmia or a heart attack. It was miserable."

Walsh, 48, of Andover, New Hampshire, suffered these debilitating symptoms for five years until undergoing a new procedure at the Mass General Heart Center that freezes heart tissue to restore normal heart rhythm.

Cryoballoon ablation

Atrial fibrillation is the most common type of irregular heart beat — or arrhythmia — affecting more than 2.5 million Americans. AF causes the upper chambers of the heart to beat too fast, inhibiting the movement of blood in and out of the heart. AF diminishes a person's overall quality of life with symptoms like fatigue, shortness of breath and chest pain, while also significantly increasing their risk of stroke and heart failure.

AF is often treated with drug therapy, but for many patients drugs alone are not sufficient to ease the suffering.

"My doctors had me try several medications, but they were not working and the arrhythmias were coming back just as bad. I broke through them all at the maximum doses," he explained. "I wanted to try something that would keep the AF from coming back."

Through the father of one of the students at the boarding school where he is a teacher and coach, Walsh learned about a new treatment available at Mass General — cryoballoon ablation.

During this minimally invasive procedure, doctors insert a balloon catheter into a blood vessel in the upper leg and snake it through the circulatory system until it reaches the heart. Once in place, the balloon is inflated and extremely cold energy flows through the catheter, freezing the heart tissue that is causing the irregular heart beat.

Walsh made an appointment with Jeremy Ruskin, MD, director of the Mass General Cardiac Arrhythmia Service, where doctors have been part of clinical trials evaluating this new procedure.
"Mr. Walsh was a good candidate for the procedure because he had paroxysmal AF, and we were seeing promising results among patients with that type of arrhythmia," said Moussa Mansour, MD, a cardiologist with the Heart Center's Cardiac Arrhythmia Service and director of the Electrophysiology Laboratory.

In October 2009, Walsh went in for the procedure, which was done using conscious sedation. The procedure lasted three hours, and after one night in the hospital Walsh was on his way home. Days after the procedure, he had not had any irregular heart rhythms. His doctors were cautions and told him not to worry if he had an episode, but six months later he has still not had any symptoms.

"I would have done anything to be free of the AF. I wanted to be healthy again," he said. "I can't say 100 percent that this is never going to happen again, but I am feeling great now."


Cryoballoon ablation is still being tested and is not approved by the U.S. Food and Drug Administration.  However, results from the large, multicenter trial called STOP AF have been promising.

Jeremy Ruskin, MD, director of the Cardiac Arrhythmia Service at Mass General, presented data from 245 highly symptomatic patients at the Heart Rhythm Society’s annual Scientific Sessions in May. Results indicated that patients treated with cryoablation had a treatment success rate of 69.9 percent after 12 months, compared to 7.3 percent for those who received traditional drug therapy. Results also showed that cryoablation improved the physical and mental quality of life for patients in the study. Overall, only 20 percent of the cryoablation-treated patients reported any symptoms after 12 months.

“The results from the STOP-AF trial are promising. They indicate that cryoballoon ablation is effective for treating arrhythmias in patients who are not being helped by the traditional drug therapies,” said Dr. Mansour.

Cryoballoon ablation may also have several additional benefits.

“In cryoablation, the balloon freezes the whole vein at once rather than burning several points of the vein, as is done during radiofrequency ablation, another common treatment for AF. Using heated energy to burn the vein can sometimes disrupt the lining of the heart or cause esophageal injury,” he said. “This is one of the several small advantages of cryoablation."

Cryoballoon ablation is available as part of ongoing clinical trials at Mass General. Michael Walsh will have a final follow-up appointment one year after his procedure.

“Even though it’s still being tested, I felt this was the best option for me,” said Walsh. “I didn’t want to control the AF, I wanted to eliminate it. So far I couldn’t be happier.”

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