Studies support post AF ablation drug therapy and remote ICD follow-up
Three late-breaking clinical trial results presented at the 2008 Heart Rhythm Society (HRS) meeting in San Francisco last week reported good results for drug therapy immediately following ablation of atrial fibrillation (AF), the use of a new antiarrhythmic drug and the remote monitoring of pacemaker patients.

Researchers at the Hospital of the University of Pennsylvania in Philadelphia conducted the 5A Study (AntiArrhythmics After Ablation of Atrial fibrillation), which prospectively randomized patients with paroxysmal AF who had undergone ablation to receive antiarrhythmic drugs or to not receive empiric antiarrhythmic treatment.

“It is common for atrial arrhythmias to follow atrial fibrillation ablation early on and antiarrhythmic drugs are often prescribed during this period to reduce arrhythmia episodes, however, the benefit of this approach is unclear,” said lead author Jean-Francois Roux, MD, an electrophysiology fellow. “Our study was designed to determine if there are in fact benefits.”

Of the 110 patients enrolled, 53 were randomized to receive antiarrhythmic drugs and 57 received no antiarrhythmic drugs. Researchers found that antiarrhythmic drug treatment during the six weeks following AF ablation was well tolerated and reduced the incidence of clinically significant atrial arrhythmias and the need for cardioversion or hospitalization.

Another HRS study, presented by Stefan H. Hohnloser, MD, and colleagues from J.W. Goethe University in Frankfurt, Germany, reported that dronedarone (Multaq, Sanofi-Aventis), a new antiarrhythmic multichannel blocking compound, reduced the incidence of cardiovascular hospitalizations or death in patients with AF.

The results were from the ATHENA Trial (A placebo-controlled, double-blind, parallel arm Trial to assess the efficacy of dronedarone 400 mg bid for the prevention of cardiovascular Hospitalization or death from any cause in patiENts with Atrial fibrillation/atrial flutter).

“ATHENA is the first large trial of an antiarrhythmic agent that measures if an antiarrhythmic drug can reduce the composite outcome of the time to first cardiovascular hospitalization or death from any cause in an AF population,” Hohnloser said. “The positive effects of dronedarone on the AF population are significant and extremely important to the field of cardiology.”

The trial randomized 4,628 patients with AF, atrial flutter or with a history of the disorder to receive dronedarone or placebo with a minimum follow-up of one year. The primary study outcome was the time to first cardiovascular hospitalization or death from any cause and secondary outcomes were total death, cardiovascular death and cardiovascular hospitalization.

The study findings included:
  • 24.2  percent reduction in the risk of cardiovascular hospitalization or death from any cause during the study period, the study primary endpoint;
  • 30 percent reduction in the risk of cardiovascular death (including sudden death) on top of standard therapy, including rate control drugs and antithrombotics, a pre-specified secondary endpoint;
  • 25.5 percent reduction of first cardiovascular hospitalizations;
  • A trend towards 16 percent less death from any cause; and
  • Lower mortality overall in the dronedarone arm compared to the placebo group at all times of the study.
In the third study, Bruce L. Wilkoff, MD, and colleagues at The Cleveland Clinic Foundation found that physicians can detect and diagnose clinically actionable events earlier in pacemaker patients who utilize remote interrogation compared to those that are followed via routine office visits augmented by transtelephonic monitoring (TTM).
The results are part of the PREFER Trial (Pacemaker REmote Follow-up Evaluation and Review), which is the first trial to compare remote monitoring diagnosis rates to diagnosis rates using traditional pacemaker follow-up, according to Wilkoff.

The prospective, randomized trial analyzed data from 897 patients from 50 centers throughout the U.S.

At enrollment, patients were randomized 2:1 to have pacemaker follow-up by a combination of in-person programming evaluations augmented by either remote interrogation or transtelephonic rhythm strip evaluations. At each follow-up visit or scheduled transmission, physicians reviewed the available data for pre-specified clinically actionable events.

“With current pacemaker systems continuously recording clinical information, clinicians now have robust and objective data to diagnose clinical events. However, this information is only valuable if providers can access it in a timely manner that enables clinical intervention before the event progresses,” Wilkoff said. “Internet-based remote monitoring tools now make it possible for clinical information to reach physicians with minimal intrusiveness for both the patient and the clinician.”

At the end of the year-long trial, results showed that clinically actionable events are detected earlier in patients that used remote interrogation instead of TTM monitoring. Overall, the researchers detected less than 2 percent of events by remote transmission in patients using TTM monitoring, while more than 60 percent were detected in the patient group that used remote interrogation.

These studies show that new drug therapies and treatment protocols, as well as more sophisticated device data management, promise to benefit the ever-increasing number of people suffering from AF and the physicians who treat them.