New AHRQ Study Finds Mixed Evidence on Use of Radiofrequency Catheter Ablation for...

New AHRQ Study Finds Mixed Evidence on Use of Radiofrequency Catheter Ablation
for Treating Atrial Fibrillation

ROCKVILLE, Md., July 6 /PRNewswire-USNewswire/ -- A procedure that sends
targeted energy into the heart through a catheter can be used to treat a
common type of irregular heartbeat, but little is known about the treatment's
long-term benefits and the best methods and circumstances for applying it,
according to a new report funded by HHS' Agency for Healthcare Research and
Quality.

The report examines the use of a procedure called radiofrequency catheter
ablation to treat a type of irregular heartbeat known as atrial fibrillation.
The new comparative effectiveness report found that the procedure has been
shown to provide benefits in maintaining normal heart rhythm over short
periods of time (up to 1 year) but found little evidence indicating whether
the procedure reduces the chance that patients will experience atrial
fibrillation over the long term.

The report, which compared radiofrequency catheter ablation to
medication-based therapy, also found that the effect of the procedure on
stroke, a major risk for patients with atrial fibrillation, is unknown.
Radiofrequency catheter ablation - a procedure in which a long, thin, flexible
tube is put through a blood vessel into the heart - often is used when
medications do not work. In this procedure, energy pulses are delivered
through the catheter to the heart, destroying small areas of heart tissue
where abnormal electrical signals may cause an arrhythmia to start.

Different techniques and instruments can be used for the procedure. While
there is no strong evidence to suggest that one particular technique is best
for any given patient, there is general consensus concerning a basic approach
to ablation procedures for atrial fibrillation. In addition, there is little
evidence indicating the procedure's effectiveness when used as a first-line
therapy instead of medication.

"Radiofrequency holds promise for treating atrial fibrillation, but it is
clear that more research is needed to demonstrate its potential long-term
benefits," said AHRQ Director Carolyn M. Clancy, M.D. "This report
crystallizes the questions that researchers need to ask going forward."

Atrial fibrillation, the most common type of irregular heartbeat in adults,
affects more than 2.2 million Americans, putting them at risk for heart
failure, blood clots, or stroke. Patients with atria fibrillation are
typically treated with medication first, but medicines only work for about
half of patients for preventing recurrence of atrial fibrillation.

The report calls for more research on the effect of radiofrequency catheter
ablation on quality of life. In particular, more research is needed for groups
of patients for whom the research is especially lacking, such as women, the
elderly, and patients who have other conditions such as heart failure or high
blood pressure.

Earlier this year, HHS' Food and Drug Administration approved the first two
ablation catheters indicated for use in treating atrial fibrillation, in the
United States. However, physicians often use other catheters that have not
been approved by the FDA for atrial fibrillation. The FDA also found that
there is no conclusive evidence that people whose symptoms are reduced with
ablation are less likely to have a stroke. Therefore, the FDA explicitly
endorsed existing clinical guidelines that recommend that patients at risk for
stroke continue to take preventive blood-thinning medications after
radiofrequency catheter ablation.

As a condition of catheter approvals, the FDA mandated that the catheters'
manufacturer must conduct two post approval studies (PAS) to collect long term
safety data. The mandated studies apply only to FDA-approved catheters, and
not to devices used off-label in clinical practice. The first PAS is a post
approval registry, which will collect safety (adverse event) data and operator
experience information through 7 days post-treatment with the approved
ablation catheters. The study will also collect data on long term safety
(adverse events) data, such as death, stroke, myocardial infarction,
clinically manifested pulmonary vein stenosis, etc., at 5 years
post-treatment. The second PAS is a subgroup analysis from an ongoing larger
study that will look at the incidence of stroke, and compare the 3-year
incidence of stroke between patients treated with the approved ablation
catheters versus patients treated with medication. This study will analyze
total mortality, serious bleeding and cardiac arrest.

Also, last week, the FDA approved a new medication, dronedarone, for treatment
of atrial fibrillation. For more information go to:
http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm170276.htm.

AHRQ's new report, Comparative Effectiveness of Radiofrequency Catheter
Ablation for Atrial Fibrillation, is the newest analysis from the Agency's
Effective Health Care program. That program, authorized by the Medicare
Prescription Drug, Improvement, and Modernization Act, represents an important
federal effort to compare alternative treatments for health conditions and
make the findings public. The program is intended to help patients, doctors,
nurses, and others choose the most effective treatments. Information,
including the new report, can be found at
http://www.effectivehealthcare.ahrq.gov.

Editor's Note: Use Twitter to get AHRQ news updates: www.twitter.com/ahrqnews.

SOURCE Agency for Healthcare Research & Quality

AHRQ Public Affairs, +1-301-427-1998, +1-301-427-1855