Chapter 1
Indications for Catheter and Surgical Ablation of Atrial Fibrillation
Hugh Calkins
Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Professor of Medicine, Baltimore, MD, USA
Introduction
The indications for catheter ablation of atrial fibrillation have been defined by three major documents. The first is the 2012 HRS Consensus Document on Catheter and Surgical Ablation of Atrial Fibrillation [1], the second is the European Society of Cardiology 2010 Guidelines for the Management of Atrial Fibrillation [2,3], and the third are the ACC/AHA/HRS Guideline for the Management of the Patients with Atrial Fibrillation [4]. In this chapter, we will review, compare, and contrast the indications for AF ablation, as defined in each of these three documents. We will also discuss areas of controversy.
The 2012 HRS/EHRA/ECAS Consensus Document on Catheter Ablation of Atrial Fibrillation
The 2012 HRS/EHRA/ESC Expert Consensus Document on Catheter and Surgical Ablation of Atrial Fibrillation was an update on the original Expert Consensus Document that was published in 2007. The recommendations concerning the indications for catheter and surgical ablation of atrial fibrillation as defined by the 2012 HRS/EHRA/ECAS Consensus Document are as follows:
Symptomatic AF refractory of intolerant to at least one class 1 or 3 antiarrhythmic medication
- Paroxysmal AF: Catheter ablation is recommended. Class 1, LOE A.
- Persistent AF: Catheter ablation is reasonable. Class 2A, LOE B.
- Long-standing Persistent AF: Catheter ablation may be considered class 2B, LOE B.
Symptomatic AF prior to initiation of antiarrhythmic drug therapy with a class 1 or 3 antiarrhythmic agent
- Paroxysmal: Catheter ablation is reasonable. Class 2A, LOE B.
- Persistent: Catheter ablation may be considered. Class 2A, LOE C.
- Long-standing persistent: Catheter ablation may be considered. Class 2A, LOE C.
Concomitant Surgical Ablation of Atrial Fibrillation
Symptomatic AF refractory of intolerant to at least one class 1 or 3 antiarrhythmic medication.
- Paroxysmal AF: Concomitant surgical ablation is recommended. Class 2A, LOE C.
- Persistent AF: Concomitant surgical ablation is reasonable. Class 2A, LOE C.
- Long-standing Persistent AF: Concomitant surgical ablation may be considered class 2A, LOE C.
Symptomatic AF prior to initiation of antiarrhythmic drug therapy with a class 1 or 3 antiarrhythmic agent
- Paroxysmal: Concomitant surgical ablation is reasonable. Class 2A, LOE C.
- Persistent: Concomitant surgical ablation may be considered. Class 2A, LOE C.
- Long-standing persistent: Concomitant surgical ablation may be considered. Class 2B, LOE C.
Stand-Alone Surgical Ablation of Atrial Fibrillation
Symptomatic AF refractory of intolerant to at least one class 1 or 3 antiarrhythmic medication.
- Paroxysmal AF: Stand-alone surgical ablation is recommended. Class 2A, LOE C.
- Persistent AF: Stand-alone surgical ablation is reasonable. Class 2A, LOE C.
- Long-standing Persistent AF: Stand-alone surgical ablation may be considered class 2A, LOE C.
Symptomatic AF prior to initiation of antiarrhythmic drug therapy with a class 1 or 3 antiarrhythmic agent
- Paroxysmal: Stand-alone surgical ablation is reasonable. Class 2A, LOE C.
- Persistent: Stand-alone surgical ablation may be considered. Class 2A, LOE C.
- Long-standing persistent: Stand-alone surgical ablation may be considered. Class 2B, LOE C.
Indications for Catheter Ablation of Atrial Fibrillation as Defined by the 2010 European Society of Cardiology Guidelines for Atrial Fibrillation Management
The most recent document on AF management put forth by the European Society of Cardiology was published in 2012 [3]. This document is an update of the 2010 European Society of Cardiology AF Guidelines [2].
The updated 2012 indications are as follows:
- Catheter ablation of symptomatic paroxysmal AF is recommended in patients who have symptomatic recurrences of AF on antiarrhythmic drug therapy and who prefer further rhythm control therapy, when performed by an electrophysiologist who has received appropriate training and is performing the procedure in an experienced center. Class 1, LOE A.
- Catheter ablation of AF should be considered as first-line therapy in selected patients with symptomatic paroxysmal AF as an alternative to antiarrhythmic drug therapy, considering patient choice, benefit, and risk. Class 2A, LOE B.
The indications that remain unchanged from the 2010 document are as follows:
- Ablation of persistent symptomatic AF that is refractory to antiarrhythmic therapy should be considered as a treatment option. Class 2a, LOE B.
- Catheter ablation of AF in patients with heart failure may be considered when antiarrhythmic medication, including amiodarone, fails to control symptoms. Class 2b, LOE B.
- Catheter ablation of AF may be considered in patients with symptomatic long-standing persistent AF refractory to antiarrhythmic drugs. Class 2b, LOE C. Indications for catheter ablation of atrial fibrillation as defined by the 2014 ACC/EHRA/ECAS AF Management Guidelines.
In 2014, the ACC/AHA/and HRS published a guidelines document focused on atrial fibrillation management [4]. The recommendations put forth in this document concerning the indications for catheter ablation of atrial fibrillation are as follows:
Class I
- AF ablation is useful for symptomatic paroxysmal AF refractory or intolerant to at least one class 1 or 3 antiarrhythmic medication when a rhythm control strategy is desired (Level of Evidence: A)
- Prior to consideration of ablation of AF, careful assessment of the procedural risks and outcomes relevant to the individual patient is recommended. (Level of Evidence: C)
Class IIa
- AF ablation is reasonable for selected patients with symptomatic persistent AF refractory or intolerant to at least one class 1 or 3 antiarrhythmic medication. (Level of Evidence: A)
- In selected patients with recurrent symptomatic paroxysmal AF, AF ablation is a reasonable initial rhythm control strategy prior to therapeutic trials of antiarrhythmic drug therapy, after carefully weighing risks and outcomes of drug and ablation therapy. (Level of Evidence: B)
Class IIb
- AF ablation may be considered for symptomatic long-standing persistent AF refractory or intolerant to at least one class 1 or 3 antiarrhythmic medication when a rhythm control strategy is desired. (Level of Evidence: B)
- In patients with recurrent symptomatic paroxysmal AF, it is a reasonable initial rhythm control strategy prior to therapeutic trials of antiarrhythmic drug therapy, after weighing the risks and outcomes of drug and ablation therapy (LOE B).
Class III: Harm
- AF ablation should not be performed in patients who cannot be treated with anticoagulant therapy during and following the procedure. (Level of Evidence: C)
- AF ablation of AF to restore sinus rhythm should not be performed with the sole intent of obviating need for anticoagulation. (Level of Evidence: C)
Considerations on the Published Guidelines for AF Ablation
These indications are categorized into class I, class IIa, class IIb, and class III indications. The evidence supporting these indications is graded as level A through C. In making these recommendations, the writing groups considered the body of literature published that has defined the safety and efficacy of catheter and surgical ablation of AF. Both the number of clinical trials and the quality of these trials were considered. Catheter and surgical ablation of AF are highly complex procedures, and a careful assessment of benefit and risk must be considered for each patient.
As demonstrated in a large number of published studies, the primary clinical benefit from catheter ablation of AF is an improvement in quality of life resulting from elimination of arrhythmia-related symptoms such as palpitations, fatigue, or effort intolerance (see section on Outcomes and Efficacy of Catheter Ablation of AF). Thus, the primary selection criterion for catheter ablation should be the presence of symptomatic AF. As noted above, there are many considerations in patient selection other than type of AF alone. In clinical practice, many patients with AF may be asymptomatic but seek catheter ablation as an alternative to long-term anticoagulation with warfarin or other drugs with similar efficacy. One of the important features of the indications for AF ablation described in these documents is that the guidelines viewed collectively tell us that a desire to stop anticoagulation is not an appropriate indication for AF ablation. This is stated most clearly in the 2014 ACC/AHA/HRS AF guidelines that provide a class 3 indication “harm” for performing AF ablation because of a desire to stop anticoagulation. Although retrospective studies have demonstrated that discontinuation of warfarin therapy after catheter ablation may be safe over medium-term follow-up in some subsets of patients, this has never been confirmed by a large prospective randomized clinical trial and therefore remains unproven. Furthermore, it is well recognized that symptomatic and/or asymptomatic AF may recur during long-term follow-up after an AF ablation procedure. It is for these reasons that Heart Rhythm Society Consensus Document recommends that discontinuation of warfarin or equivalent therapies postablation is not recommended in patients who have a high stroke risk as determined by the CHADS2 or CHA2DS2VASc score. Either aspirin or warfarin is appropriate for patients who do not have a high stroke risk. If anticoagulation withdrawal is being considered, additional ECG monitoring may be required, and a detailed discussion of risk versus benefit should be entertained. A patient's desire to eliminate the need for long-term anticoagulation by itself should not be considered an appropriate selection criterion. In arriving at this recommendation, the Task Force recognizes that patients who have undergone catheter ablation of AF represent a new and previously unstudied population of patients. Clinical trials, therefore, are needed to define the stroke risk of this patient population and to determine whether the risk factors identified in the CHADS...
