Current guidelines recommend that antiarrhythmic drug therapy is the first-line treatment for patients with symptomatic paroxysmal atrial fibrillation. However, the efficacy of different drugs varies, and a large proportion of patients stop taking them due to side effects. Previous studies have shown that single radiofrequency ablation delays the first recurrence of atrial fibrillation by 60% in patients who have failed to take ≥1 antiarrhythmic drug for atrial fibrillation, and some studies have shown that radiofrequency ablation as the first-line treatment for patients with paroxysmal atrial fibrillation reduces the recurrence rate of atrial fibrillation compared with drug therapy. However, it is controversial whether radiofrequency ablation is better than antiarrhythmic drugs as first-line treatment for patients with paroxysmal AF.
In this regard, Dr. Morillo et al. from Canada conducted the RAAFT-2 study to evaluate whether radiofrequency ablation is superior to drug therapy as first-line treatment for patients with paroxysmal AF who have never been treated with antiarrhythmic drugs. The results found that the recurrence rate of tachyarrhythmic atrial tachycardia treated with radiofrequency ablation was lower than drug therapy in patients with paroxysmal atrial fibrillation who had never received antiarrhythmic drugs.
A total of 127 patients with never-treated paroxysmal atrial fibrillation were enrolled in the RAAFT-2 study, and included patients were treated with antiarrhythmic drugs or radiofrequency ablation and followed up for 24 months. The study primary endpoint event: the occurrence of tachyarrhythmias lasting ≥30 seconds after treatment, and secondary endpoint events: recurrent tachyarrhythmias and improvement in quality of life after 1 year of follow-up.
The results of the study showed that the incidence of the primary effective endpoint events was 72.1% and 54.5% in the antiarrhythmic drug group and the first recurrence of symptomatic atrial fibrillation, atrial flutter, and atrial tachycardia was 59% and 47% in the radiofrequency ablation group, respectively. No death or stroke occurred in either group, but the incidence of adverse events was 9% (including 4 cases of pericardial tamponade) and 5% in the radiofrequency ablation and drug groups, respectively. Forty-three percent of patients in the drug treatment group underwent radiofrequency ablation after 1 year. Quality of life was lower in both groups at baseline level and improved after 1 year, but there was no significant difference in the degree of improvement between the two groups.
I. Comparison of the occurrence of primary and secondary endpoint events in the radiofrequency ablation group and the drug treatment group.
The study concluded that in patients with paroxysmal atrial fibrillation who had never received antiarrhythmic drugs, the recurrence rate was lower in patients treated with radiofrequency ablation than with drug therapy, although both had a higher recurrence rate of tachyarrhythmic tachycardia at 2 years.
Considering the high incidence of adverse events and the improvement in quality of life comparable to that of drugs, its use as a first-line treatment option for patients with paroxysmal AF not receiving drug therapy needs to be weighed and individualized.
Second, JAMA review: Is the era of radiofrequency ablation as the first-line treatment for atrial fibrillation approaching?
Dr. Calkins from Johns Hopkins Hospital commented on the study, as follows.
Over the past 10 years, radiofrequency ablation has evolved from an unproven treatment for atrial fibrillation to a very important treatment for patients with atrial fibrillation. The European Heart Rhythm Association and the European Society of Cardiology have unanimously recommended radiofrequency ablation as a “Class IA” for patients with paroxysmal AF who have failed antiarrhythmic drug therapy (at least 1 year) and a “Class IIB” for patients with paroxysmal AF who have been treated with drug therapy, which is consistent with the This is similar to the 2012 update of the European Society of Cardiology atrial fibrillation guidelines.
The results of the RAAFT-2 study should be analyzed in the context of the papers on atrial fibrillation ablation and the implementation of radiofrequency ablation.
The clinical significance of the study was assessed in the following four main aspects.
1. The results of the study are well documented
The study was conducted in a rigorous manner and in accordance with the 2012 HRS/EHRA/ECAS recommended definitions of success and complications of radiofrequency ablation, as well as monitoring and follow-up protocols.
This study is not the first to evaluate radiofrequency ablation as first-line treatment for atrial fibrillation, as the RAAFT-1 study published by Dr. Wazni et al. in 2005 compared the efficacy of radiofrequency ablation with drug therapy as first-line treatment for atrial fibrillation. the RAAFT-1 study demonstrated that radiofrequency ablation was superior to antiarrhythmic drugs at 12 months.
Recently, Dr. Nielsen et al. published the results of the MANTRA-PAF study, which also compared the efficacy of radiofrequency ablation and drug therapy as first-line treatment for AF, but included 294 patients. the MANTRA-PAF study was negative, with no difference in the cumulative burden of AF between the two groups, but during the 24-month follow-up period, the burden of AF was less in the ablation group than in the drug group, and complications in the ablation group The complications in the ablation group included one death and three cases of pericardial tamponade.
2. Novel study topic
The results of this study suggest that radiofrequency ablation is safe and effective in the treatment of paroxysmal atrial fibrillation. Previous studies have shown that radiofrequency ablation is not a curative treatment for most patients with atrial fibrillation. Atrial fibrillation is more complex than other types of supraventricular tachycardia, which can often be cured by radiofrequency ablation.
In addition, this study showed that either radiofrequency ablation or medication as first-line treatment improved quality of life, but there was no difference in the level of improvement between the 2 groups.
3. Importance of the study: Complication rates in the RAAFT-2 study were much higher than expected
The RAAFT-2 study showed that radiofrequency ablation is not a zero-risk operation, with a complication rate of 9% in the radiofrequency ablation group, including 6% for pericardial tamponade.
This complication rate is higher than that reported in the Global Survey of Atrial Fibrillation Ablation and the recently published in-hospital complication rate of 93,000 catheter ablations. The complication rate in the RAAFT-2 study was much higher than expected considering the level of expertise of the operator and the health of the patient.
4. The study has important clinical implications for radiofrequency ablation operators and guideline makers
The results of this trial study strongly support the 2012 HRS/EHRA/ECAS guidelines on atrial fibrillation ablation treatment options and the 2012 ESC atrial fibrillation update. However, patient criteria and operator expertise are important considerations, with some patients strongly preferring radiofrequency ablation to antiarrhythmic medication. Some operators are inexperienced in AF ablation and have high procedural complications, while others are experienced and have minimal procedural complications.
Clinically, it is difficult to find patients who wish to undergo radiofrequency ablation before they have been on antiarrhythmic medication for 1 year, and this is even more evident when patients are informed of the risks associated with the procedure. For some subgroups of patients with AF (e.g., those with both paroxysmal AF and significant sinus node dysfunction), radiofrequency ablation is appropriate as first-line treatment for AF. In patients with both paroxysmal AF and significant sinus node dysfunction, although the previous treatment option for such patients was pacemaker implantation + antiarrhythmic drugs, the results of the study suggest that radiofrequency ablation may be able to control atrial fibrillation without pacemaker implantation.
This study has important clinical implications for the safety and efficacy of radiofrequency ablation in the treatment of symptomatic paroxysmal atrial fibrillation. the RAAFT-2 study not only provides important new information for the ablation treatment of atrial fibrillation, but also suggests possible complications associated with interventions such as ablation of atrial fibrillation.