When it comes to atrial fibrillation (AF), which affects approximately 5 million people worldwide, medication is generally recommended as the first-line therapy with radiofrequency ablation, a type of healing electrical energy, recommended as a next resort. A new study from researchers at McMaster University in Ontario found that among patients with intermittent AF, treatment with catheter ablation resulted in a lower rate of abnormal heart rhythms and episodes of AF. “We conclude that Ablation is better than antiarrhythmic drugs,” Dr. Carlos A. Morillo told Medical Daily in an email. “Indeed Ablation was superior in increasing the time to first recurrence of any atrial tachycardia and markedly reduced the repeated episodes of atrial fibrillation.”
Facts About Atrial Fibrillation and Catheter Ablation
Atrial fibrillation often impairs quality of life, independent of its severity, plus AF is associated with an increased risk of stroke. AF is the most common type of arrhythmia, where the rate or rhythm of the heartbeat becomes disordered, with the heart beating too fast or too slow or with an irregular rhythm. People who have AF may not feel symptoms. However, even in such cases, AF may still increase the risk of stroke or heart failure. For some patients, AF may happen rarely or it may become an ongoing or long-term heart problem that lasts for years.
The goal for most patients with paroxysmal AF is return to a normal heart beat. Although this usually means a prescription of antiarrhythmic drugs, the success rate for medication varies. Past studies suggest that preventing recurrence of AF at six months to a year occurs in only 46 percent of all cases where medicine is prescribed. Meanwhile, too many patients discontinue taking their pills due to side effects or adverse events.
On the other hand, radiofrequency catheter ablation is an invasive treatment and for this reason it is generally recommended, with some exceptions, only after at least one antiarrhythmic drug has failed. During catheter ablation, a series of catheters (thin, flexible wires) are put into a blood vessel in a patient’s arm, upper thigh, or neck, and then the wires are guided into the patient’s heart. A special machine sends radiofrequency (RF) energy to the heart through one of the catheters. The energy produces a heat that destroys small areas of heart tissue where abnormal heartbeats may cause an arrhythmia to start. Catheter ablation has potential risks, including bleeding, infection, and pain at the catheter insertion site, while more serious problems include blood clots and puncture of the heart.
Results of the Study
For the study, Morillo and colleagues compared ablation to drug treatment as a first-line therapy for paroxysmal AF in patients who had never received treatment. Participation transpired at 16 centers in Europe and North America and included 127 patients: 66 received radiofrequency ablation, while 61 received antiarrhythmic medication.
What did they find? “Among patients with paroxysmal AF without previous anti-arrhythmic drug treatment, ablation compared with antiarrhythmic drugs resulted in a lower rate of recurrent atrial tachyarrhythmias at two years,” the authors wrote in their research published Tuesday in JAMA. “However, recurrence was documented in approximately 50% of patients.”
More specifically, the researchers defined recurrence of an atrial tachyarrhythmia lasting longer than 30 seconds as the primary outcome. This occurred more often in the antiarrhythmic drug group than in the ablation group: 44 patients (72 percent) versus 36 patients (55 percent). Symptomatic recurrence of abnormal rhythm was more common with drug treatment: 36 patients (59 percent) compared with 31 patients (47 percent). Asymptomatic AF was also more frequently observed among those receiving medicine: 11 patients (18 percent) compared with six (nine percent). No deaths or strokes were reported in either group, though the ablation group had four cases of cardiac tamponade — a medical emergency that begins with the accumulation of a large amount of fluid, usually blood, near the heart that interferes with its performance. “When offering ablation … the risk/benefit ratio should be weighed and discussed with the patient,” Morillo told Medical Daily.
Source: Morillo CA, Verma A, Connolly SJ, et al. Radiofrequency Ablation vs Antiarrhythmic Drugs as First-Line Treatment of Paroxysmal Atrial Fibrillation (RAAFT-2) A Randomized Trial. JAMA. 2014.