Atrial fibrillation (AF or AFib) is the most common type of cardiac arrhythmia, affecting millions of people worldwide. Researchers have now developed a new procedure that shows great promise as a safe, rapid and effective alternative to existing surgical methods used to treat the condition.
In people with atrial fibrillation, the upper chambers of the heart (atria) beat erratically or “flutter” so that blood cannot flow to the lower chambers (ventricles). AF can be a one-time, occasional, or permanent state.
Treatment of persistent atrial fibrillation is important because the irregularly beating atria are prone to clot formation. A clot can break off, circulate in the bloodstream, lodge in a blood vessel in the brain, and cause a stroke. Treatment includes medications to slow or normalize the heart rhythm, blood thinners to reduce the formation of blood clots, or surgery.
A procedure called catheter ablation is an effective treatment for symptomatic atrial fibrillation that does not respond to medication. A long, flexible tube feeds the heart’s blood vessels through a vein in the leg, neck, or under the collarbone. The traditional method is thermal ablation, which applies heat or extreme cold to the tissue causing the arrhythmia to ablate (destroy) the tissue and create scar tissue that helps prevent recurrence.
A new international study instead used electrical pulses to ablate heart tissue and found it to be as effective as thermal energy in treating atrial fibrillation. Less risk of illness.
This technique, called pulsed-field ablation, uses electrical pulses to create tiny holes in the heart muscle cell membrane, causing the cells to die. It was formerly used to treat cancer by targeting and killing tumor cells, but only recently was it considered suitable for treating arrhythmias.
The study was conducted at 41 sites in 9 countries: USA, Canada, Australia, Austria, Belgium, France, Japan, Netherlands and Spain. Participants had AF that did not respond to drug treatment. Half of the participants had paroxysmal AF, in which episodes of arrhythmias self-terminated and lasted no more than a week, and half had persistent AF, in which episodes lasted at least one week and did not end spontaneously.
Physicians first treated one participant at a time to gain experience with the pulsed field ablation technique, then performed an additional 300 treatments on all sites.
Sixty-six percent of participants with paroxysmal atrial fibrillation did not experience an episode of atrial fibrillation between 3 and 12 months after the procedure. Among patients with persistent atrial fibrillation, 55% had no episode of atrial fibrillation during the same period. These rates are consistent with results achieved with thermal ablation.
Compared to thermal ablation, which can damage heart valves and blood vessels, the incidence of treatment-related adverse events was very low, one in each participant group.
Moreover, the pulsed field ablation procedure takes less than an hour, which is significantly faster than thermal methods, which typically take two hours or more to complete. All participants reported significant improvements in quality of life.
“The efficacy of this procedure is similar to that seen with thermal ablation, but much faster and safer,” said Dr. Atul Verma, lead author of the study. “Many physicians believe that pulsed-field ablation will be the primary method of performing ablation in the future.In that sense, this is truly a paradigm shift.”
The researchers note limitations of this study, in particular that no control group was used. Although larger studies are needed to confirm the safety of the procedure, researchers believe that the safety and success rate of pulsed field ablation will improve as technology advances.
The study was published in a journal Circulation.
Source: American College of Cardiology by EurekAlert!
