Heart Failure Patients Fare Better With Catheter Ablation Versus Amiodarone Treatment

March 16, 2015—The American College of Cardiology (ACC) announced the presentation of results from the AATAC (Ablation vs Amiodarone for Treatment of Persistent Atrial Fibrillation in Patients With Congestive Heart Failure and an Implanted Device) multicenter randomized trial at the 64th annual scientific session of the ACC in San Diego, California. 

The study’s Lead Investigator is Luigi Di Biase, MD, who is a cardiologist and electrophysiologist at St. David’s Medical Center and the Albert Einstein College of Medicine at Montefiore Hospital in New York, New York.

According to the ACC, the study found that among patients with heart failure and atrial fibrillation, those who underwent catheter ablation were less likely to die, be hospitalized, or have recurrent atrial fibrillation than patients taking amiodarone, a heart rhythm–regulating drug. Catheter ablation was most successful in procedures where ablation was required in other areas in addition to the pulmonary vein, the AATAC investigators concluded. 

As noted by the ACC, heart failure and atrial fibrillation often co-occur and are two of the most common heart problems in older adults. In the new study, 71% of patients treated with catheter ablation were free of atrial fibrillation, the AATAC study’s primary endpoint, after 2 years of follow-up compared with only 34% of patients treated with the anti-arrhythmic drug amiodarone who were free of symptoms at 2 years. 

Dr. Di Biase commented in the ACC press release, “Even when it is effective, amiodarone often needs to be discontinued after a while due to serious long-term side effects. Our study suggests that in patients with heart failure and atrial fibrillation, catheter ablation is an effective alternative treatment that can help patients avoid or discontinue this drug to reduce the risk of these long-term side effects.”  

He added, “It is very important to control persistent atrial fibrillation in patients with heart failure. These patients need every bit of blood that the heart can pump, so it becomes particularly dangerous when an arrhythmia happens. People with both of these conditions frequently wind up in the hospital.” 

The AATAC study was composed of more than 200 patients treated in eight hospitals in Europe and United States. All patients had heart failure, atrial fibrillation, and either an implantable cardioverter defibrillator or cardiac resynchronization therapy with defibrillation. Patients were randomly assigned 1:1 to undergo catheter ablation or treatment with amiodarone. 

The investigators found that in addition to having a higher rate of freedom from atrial fibrillation, participants who underwent catheter ablation also had lower rates of hospitalization and mortality during the 2-year follow up: 31% of patients who underwent ablation were subsequently hospitalized compared to 57% of patients who took amiodarone; 8% of patients who underwent ablation died during the course of the study compared to 18 % of patients who took amiodarone. 

Dr. Di Biase advised that the type and extent of the ablation procedure had a marked impact on the procedure’s success rate. He stated, “If the ablation is limited to the pulmonary vein alone, the success rate goes down—almost to the level of the amiodarone treatment. The highest success rates were for procedures in which other areas (in addition to the pulmonary vein) were ablated.” 

The specific areas that benefit from additional ablation depend on each patient’s individual condition. In addition, many patients in the study required more than one ablation procedure to achieve freedom from atrial fibrillation. 

Another limitation of the AATAC study is that not all hospitals have the experience and equipment necessary to properly perform catheter ablation, stated Dr. Di Biase. As a result, the advantage of ablation over amiodarone might not be as dramatic outside of top-tier hospitals. Further research would help to track the procedure’s effectiveness in a broader variety of circumstances.