BOSTON — An expert consensus panel that issued recommendations on catheter ablation for ventricular arrhythmias says that catheter ablation should be “considered early” in treating patients with recurrent ventricular tachycardia, with a reduced focus on first trying several antiarrhythmia drugs.
“Many of us see patients [with a ventricular arrhythmia] who are tried on a series of anti-arrhythmia drugs that have a negative impact on their quality of life and are referred for ablation relatively late,” said Dr. William G. Stevenson, director of the clinical cardiac electrophysiology program at Brigham and Women's Hospital, Boston, and cochairman of the expert panel. “We feel that earlier consideration of ablation is warranted,” usually after one antiarrhythmia drug fails, although immediate use of ablation is appropriate for patients with ventricular tachycardia (VT) storms or incessant VT, Dr. Stevenson said during a press briefing at the Heart Rhythm Society's annual scientific sessions where the consensus recommendations were announced.
“In the past, the first step was drugs. We now know that drugs frequently fail” or are contraindicated in many patients, said Dr. Etienne M. Aliot, an electrophysiologist at Brabois Hospital in Vandoeuvre-les-Nancy, France, and cochairman of the panel. For many patients, catheter ablation is the first-line treatment because it works well.
The expert panel issuing recommendations on the use of catheter ablation for ventricular arrhythmias was organized by the Heart Rhythm Society and by the European Heart Rhythm Association. The guidelines appear in the June issue of Heart Rhythm (2009;6:886-933).
The recommendations from the panel represent an expert consensus opinion and don't rise to the level of formal, evidence-based guidelines, stressed Dr. N.A. Mark Estes, president of the Heart Rhythm Society and professor and director of the cardiac arrhythmia service at Tufts Medical Center, Boston. “In most cases we don't have good randomized, controlled trials” that clearly document the role for catheter ablation for ventricular arrhythmias and the best way to deliver the treatment, he noted.
In fact, catheter ablation applied to ventricles remains a developing field that until now has not had a comprehensive review of where the treatment stands.
“Over the past several years there has been a great deal of progress in catheter ablation of atrial arrhythmias, with less focus on ventricular arrhythmias, which is a smaller group of patients,” Dr. Stevenson said. “Many of the ablation technologies brought into common use [for atrial arrhythmias] are well applied to ventricular arrhythmias, but we know less about them. A goal of this consensus was to bring together information that is not easily accessed in the literature.”
Demand for catheter ablation of ventricles is growing as the use of implantable cardioverter defibrillators (ICDs) grows. Dr. Stevenson estimated that about 10,000 ICDs are now implanted into U.S. patients every month.
“We know that shocks from ICDs are associated with a reduced quality of life for patients,” he said. While ICDs are seen as a valuable safety net for patients at high risk for VT and other life-threatening arrhythmias, ICD recipients generally are also treated to reduce their risk for VT episodes and shocks, a process that often involves catheter ablation.
Dr. Stevenson also highlighted the growing availability of catheter ablation for ventricular arrhythmia. The expert document noted that “catheter ablation outcomes derive from single-center studies. In most cases, these studies reflect the experience of large academic centers, the outcomes of which may or may not be replicated by smaller centers.” Despite this, “catheter ablation is increasingly done throughout the world,” with increasing numbers of electrophysiologists trained in the techniques, Dr. Stevenson said.
The expert panel was unable to reach a consensus on what constitutes adequate training for cardiologists performing catheter ablation of ventricular arrhythmias. In part, that was because the panel recognized that in the United States the American Council on Graduate Medical Education has guidelines in place for credentialing physicians in electrophysiology based in part on their experience with catheter ablation, although not specifically for ablation of VT, Dr. Stevenson said in an interview.
“We feel that earlier consideration of ablation is warranted,” said Dr. William G. Stevenson (left, with Dr. Etienne M. Aliot). Mitchel L. Zoler/Elsevier Global Medical News