Real long-term benefits for radio frequency catheter ablation (RCA) have yet to be seen, but a report compiled by the Department of Health and Human Services' Agency for Healthcare Research and Quality (AHRQ) on the procedure, which sends targeted energy into the heart to treat a common type of irregular heart beat, is showing that in the short-term RCA has tremendous effectiveness.

The report, which findings come from several studies on the procedure, specifically targets the use of RCA on atrial fibrillation (AF).

The new comparative effectiveness report found that the procedure has been shown to help patients in maintaining normal heart rhythm for short periods of time. AHRQ's report shows that that short period of time could be up until 1 year.

"Overall the evidence seems to show that the procedure has a temporary affect on symptoms for atrial fibrillation," Elise Berliner, Director of Technology for AHRQ, told Medical Device Daily. "What we still don't know is if there are any long term benefits."

Radio frequency 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.

The report, which compared radio frequency 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.

AHRQ officers did say that the report calls for more research on the effect of radio frequency 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, Johnson & Johnson (New Brunswick, New Jersey) got the nod from the FDA to market the NaviStar ThermoCool saline irrigated radio frequency ablation catheter and the EZ Steer ThermoCool Nav, which can be used to create small, strategically placed scars in heart tissue to block irregular electrical waves that cause atrial fibrillation (MDD, Feb. 9, 2009).

In the past the FDA approved other ablation catheters to treat arrhythmias such as atrial flutter and ventricular tachyarrhythmia, but not for AF.

However, physicians often use other catheters that have not been approved by the FDA for AF. 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 radio frequency catheter ablation.

As a condition of catheter approvals, the FDA mandated that the catheter's 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 seven 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 five 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 three-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.

AF, 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 AF are typically treated with medication first, but medicines only work for about half of patients for preventing recurrence of AF.