Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia. A variety of ablative procedures have been investigated to treat this condition. This document addresses transcatheter radiofrequency ablation and cryoablation of arrhythmogenic foci in the pulmonary veins for the treatment of atrial fibrillation.

Note: Please see the following related document for additional information:

• CG-SURG-05 Maze Procedure

Medically Necessary: 

Transcatheter radiofrequency ablation of arrhythmogenic foci in the pulmonary veins is considered medically necessary as a treatment of atrial fibrillation when the member:

• Is symptomatic; AND
• Is resistant to one (1) or more antiarrhythmic drugs (or has intolerance of or a contraindication to appropriate antiarrhythmic drug therapy).

Investigational and Not Medically Necessary:

Transcatheter radiofrequency ablation of arrhythmogenic foci in the pulmonary veins is considered investigational and not medically necessary as a treatment of atrial fibrillation in ANY of the following circumstances:

• As a first-line treatment of atrial fibrillation,
• In the absence of resistance to one (1) or more antiarrhythmic drugs (including the absence of intolerance or contraindication to appropriate antiarrhythmic drug therapy),
• Asymptomatic atrial fibrillation.

Transcatheter cryoablation of arrhythmogenic foci in the pulmonary veins as a treatment of artial fibrillation is considered investigational and not medically necessary. 

Radiofrequency Ablation

For individuals with paroxysmal atrial fibrillation (AF), transcatheter radiofrequency pulmonary vein ablation (PVA) may be considered an alternative for individuals who are symptomatic and are resistant to or unable to tolerate antiarrhythmic(class 1 or 3 ) drug therapy (Calkins, 2007). For individuals with persistent AF, it might be considered an alternative to either antiarrhythmic drug or defibrillator therapy. For individuals with permanent AF, pulmonary vein ablation may be considered an alternative either to antiarrhythmic drug therapy or ablation of the AV node followed by ventricular pacing. For all types of AF, it is possible that pulmonary vein ablation may not be curative as a sole treatment, but might alter the underlying myocardial triggers or substrate in such a way that subsequent pharmacologic therapy may become more effective.

The published literature on radiofrequency pulmonary vein ablation reflects its evolving nature, dominated by reports of the technical capability of different mapping and ablation strategies. For example, catheters with different arrays of electrodes have been specifically developed for pulmonary vein ablation and various authors have described different ablation parameters. Published studies consist mostly of single institution case series; some studies included only patients with paroxysmal AF, while others included both paroxysmal and persistent AF. In general, the success rate appears greater for paroxysmal AF.

While multi-center randomized trials comparing radiofrequency PVA to ongoing drug therapy are currently lacking and the optimal ablation technique, including the regions of the pulmonary veins and left atrium to be ablated, continue to be refined, the numbers of patients treated by catheter ablation worldwide and reported to surveyors (Cappato, 2005) are large with an increasing percentage undergoing transcatheter radiofrequency PVA in preference to other techniques (6,600 of 10,199 in 2002). While the survey recognizes the variation in mapping and procedural techniques utilized, an average of 52% patients were cured of their AF with antiarrhythmic drugs no longer being required, with an additional 23.9% cured using formerly ineffective antiarrhythmic drug therapy. PVA contributed to about two thirds of these outcome figures.

A 2004 literature review by Finta and Haines, analyzed 19 trials including 2,148 patients undergoing focal ablation and pulmonary vein isolation or linear ablation (compartmentalization) of the right atrium with or without left atrium. Of these patients, 1,991 underwent either focal ablation or isolation of pulmonary veins. Although the majority had paroxysmal atrial fibrillation (AF), patients with persistent AF were also included and had failed previous antiarrhythmic drug therapy. For the patients treated with a pulmonary vein ablation procedure, the review revealed approximately 70% had no recurrence of their AF at a median follow-up of 12.6 months, without the use of antiarrhythmic drugs.

Pappone and colleagues (2003), in a non-randomized study of 1,171 patients with symptomatic AF, compared outcomes of PVA using radiofrequency energy in 589 patients with antiarrhythmic therapy in 582 patients with a median follow-up of 900 days. Survival, AF recurrence and quality of life all significantly favored the PVA treated group. Several other studies have also reported improved quality of life measures following successful PVA in patients with symptomatic AF.

Cryoablation

Another energy source being studied for transcatheter treatment of patients with AF is cryoablation. It is hoped to be as effective as radiofrequency and ultimately safer, potentially reducing the incidence of complications. De Ponti (2005) reports:

"Cryothermal energy ablation causes less or minimal endothelial disruption, maintenance of extracellular collagen matrix and no collagen contracture related to thermal effects. Moreover, lower incidence of thrombus formation is reported with cryoenergy as compared to radiofrequency energy ablation. For these characteristics, cryothermal energy ablation can be considered an ideal and safer energy source also for pulmonary vein ablation and the incidence of both pulmonary veins stenosis and thromboembolic events is expected to be dramatically reduced by using cryoablation. On the other hand, the presence of high blood flow in the pulmonary vein may represent a considerable heat load, which may limit the size and depth of the lesion produced by cryothermal energy at the os of the pulmonary vein. Moreover, the longer time required to produce a permanent lesion may relevantly reflect on procedure duration, limiting the clinical use of this theoretically optimal energy source… Importantly, the early cryoablation experience has not evidenced, so far, development of pulmonary veins stenosis following ablation. Technologic evolution is now aimed to develop new catheter designs for circumferential ostial ablation of the pulmonary veins, with the option of deploying in the pulmonary veins an inflatable balloon to reduce the heat load related to blood flow. These devices are to be tested in a large patient cohort to assess whether these technological improvements will lead to optimization of the use of cryothermal energy, maximizing the advantages of this new technology and limiting the drawbacks encountered in its clinical use."

Although there is some published data suggesting transcatheter cryoablation is technically feasible and may be effective for the treatment of AF in some patients, the studies are in general limited by small numbers of patients studied and short follow-up periods. Clinical experience is limited and at the present time radiofrequency energy is considered the more established and widely accepted method for transcatheter ablation of AF. There is currently insufficient evidence available to draw conclusions as to whether transcatheter cryoablation is as effective as radiofrequency ablation for the abolition of AF. Prospective, randomized, comparative studies of these two energy sources are currently lacking and would be required to establish the relative long term efficacy and safety of the two techniques.

First-line Treatment and Asymptomatic Atrial Fibrillation

Although most reports involve the use of PVA in patients with AF who remain symptomatic despite drug therapy, a recent small pilot study by Wazni and colleagues in JAMA (2005), reported a randomized trial comparing pulmonary vein isolation using radiofrequency ablation to antiarrhythmic drugs as first-line treatment of symptomatic AF. Although AF recurrence (the primary study endpoint) was lower in the PVA group in the one-year follow-up period, the authors acknowledge the sample size (70 patients) and one year follow-up period were not adequate to assess therapeutic effects on certain important outcomes such as stroke. Also, larger studies are needed to confirm the safety and efficacy of pulmonary vein isolation for this purpose, and until these are performed, this should not be considered standard of care as first-line therapy for AF.

The majority of studies using both radiofrequency and cryoablation have involved patients with symptomatic AF. Randomized trials have not demonstrated improved outcomes resulting from pharmacological rhythm control versus rate control of AF. While these findings cannot necessarily be extrapolated to rhythm control using ablative techniques (partly because the use of antiarrhythmic drugs has been associated with increased mortality and partly based on different characteristics of patients undergoing PVA), there is currently inadequate data to support improved outcomes utilizing PVA versus rate control for asymptomatic patients with AF.

Atrial fibrillation has a prevalence estimated at 0.4% of the population and increases with age. The underlying mechanism of AF involves interplay between electrical triggering events and the myocardial substrate that permits propagation and maintenance of the aberrant electrical circuit. The most common focal trigger of AF appears to be located within the cardiac muscle that extends into the pulmonary veins.

Atrial fibrillation accounts for approximately one third of the hospitalizations for cardiac rhythm disturbances. Symptoms of AF (e.g., palpitations or dyspnea) are primarily related to poorly controlled or irregular heart rate. The loss of AV synchrony results in a decreased cardiac output, which can be significant in individuals with compromised cardiac function. In addition, individuals with AF are at higher risk for stroke, and anticoagulation is typically recommended. AF is also associated with other conditions, such as heart failure, valvular heart disease, hypertension and diabetes. Although episodes of atrial fibrillation can be converted to normal sinus rhythm using either pharmacologic or electroshock conversions, the natural history of AF is one of recurrence. This is thought to be related to fibrillation-induced anatomic and electrical remodeling of the atria.

Atrial fibrillation can be subdivided into paroxysmal (self-terminating), persistent (non-self-terminating), or permanent. Treatment strategies can be broadly subdivided into rate control (the ventricular rate is controlled and the atria are allowed to fibrillate) or rhythm control (there is an attempt to reestablish and maintain normal sinus rhythm). Rhythm control has long been considered an important treatment goal for AF management, although this has been recently challenged by the results of two randomized trials, both of which reported that pharmacologically maintained rhythm control offers no improvement in mortality compared to rate control. This finding cannot necessarily be extrapolated to rhythm control using ablative techniques however, since antiarrhythmic drug therapy may be associated with increased mortality. For individuals with persistent AF, rhythm control typically involves initial pharmacologic or electronic cardioversion, followed by pharmacologic maintenance of normal sinus rhythm. However, episodes of recurrent AF are typical and individuals may require multiple episodes of cardioversion. Implantable defibrillators, which are designed to detect and terminate an episode of AF, may be an alternative for individuals who would otherwise require serial cardioversions. Individuals with paroxysmal AF, by definition, do not require cardioversion but may be treated pharmacologically to prevent further episodes of AF. Treatment of permanent AF focuses on rate control, using either pharmacologic therapy or ablation of the AV node, followed by ventricular pacing. Although AV nodal ablation produces symptomatic improvement, it does require lifelong anticoagulation (due to the ongoing fibrillation of the atria), loss of AV synchrony and lifelong pacemaker dependency. Implantable atrial defibrillators are contraindicated for individuals with permanent AF.

The above treatment options are not considered curative. A variety of ablative procedures have been investigated in an attempt to modify the arrhythmia so that drug therapy becomes more effective or to potentially cure the condition. Ablative approaches focus on interruption of the electrical pathways that contribute to atrial fibrillation by modifying the triggers of AF and/or the myocardial substrate that maintains the aberrant rhythm. The Maze procedure, an open surgical procedure often combined with other cardiac surgeries, is an ablative procedure involving sequential atriotomy incisions designed to create electrical barriers that prevent the maintenance of AF. Since the inception of this technique in the early 1990's, there has been a progressive understanding of the underlying electrical pathways in the heart, such that catheter-based radiofrequency procedures have become feasible. Radiofrequency ablation is a widely used technique for a variety of supraventricular arrhythmias, when intracardiac mapping identifies a discrete arrhythmogenic focus that can be the target of ablation. The situation is more complex for atrial fibrillation, since there is not a single arrhythmogenic focus. However, the recent recognition that the triggering foci are commonly located within the myocytes extending into the pulmonary veins creates a potential target for ablation. Three basic strategies have emerged: focal ablation within the pulmonary veins, as identified by electrophysiologic mapping; segmental ostial ablation guided by pulmonary vein potential (electrical approach); or circumferential pulmonary vein ablation (anatomic approach). Circumferential pulmonary vein ablation appears to be the preferred approach at this time.

Arrhythmogenic: producing or promoting arrhythmia

Atrial fibrillation: a condition where there is disorganized electrical conduction in the atria, resulting in ineffective pumping of blood into the ventricle 

Foci: plural of focus, the origin or center of a disseminated disease

Myocardial substrate: myocardial cells that are capable of receiving and responding to electrical impulses

The following codes for treatments and procedures applicable to this document are included below for informational purposes   Inclusion or exclusion of a procedure, diagnosis or device code(s) does not constitute or imply member coverage or provider reimbursement policy.  Please refer to the member's contract benefits in effect at the time of service to determine coverage or non-coverage of these services as it applies to an individual member.

When services may be Medically Necessary when criteria are met:

When services are Investigational and Not Medically Necessary:
For the service described above when criteria are not met, or when the code describes a procedure indicated in the Position Statement section as investigational and not medically necessary.

When Services are also Investigational and Not Medically Necessary:
When the code describes a procedure indicated in the Position Statement section as investigational and not medically necessary.

Peer Reviewed Publications:

1. Arentz T, von Rosenthal J, Blum T, et al. Feasibility and safety of pulmonary vein isolation using a new mapping and navigation system in patients with refractory atrial fibrillation. Circulation. 2003; 108(20):2484-2490.
2. Bourke JP, Dunuwille A, O'Donnell D, et al. Pulmonary vein ablation for idiopathic atrial fibrillation: six month outcome of first procedure in 100 consecutive patients. Heart. 2005; 91(1):51-57.
3. Calo L, Lamberti F, Loricchio ML, et al. Left atrial ablation versus biatrial ablation for persistent and permanent atrial fibrillation: a prospective and randomized study. J Am Coll Cardiol. 2006; 47(12):2504-2512.
4. Cappato R, Calkins H, Chen SA, et al. Worldwide survey on the method, efficacy, and safety of catheter ablation for human atrial fibrillation. Circulation. 2005; 111(9):1100-1105
5. Cappato R, Negroni S, Pecora D, et al. Prospective assessment of late conduction recurrence across radiofrequency lesions producing electrical disconnection at the pulmonary vein ostium in patients with atrial fibrillation. Circulation. 2003; 108(13):1599-1604.
6. De Ponti R. Cryothermal energy ablation of cardiac arrhythmias 2005: state of the art. Indian Pacing Electrophysiol J. 2005; 5(1):12-24.
7. Dill T, Neumann T, Ekinci O, et al. Pulmonary vein diameter reduction after radiofrequency catheter ablation for paroxysmal atrial fibrillation evaluated by contrast-enhanced three-dimensional magnetic resonance imaging. Circulation. 2003; 107(6):845-850.
8. Ellenbogen KA, Wood MA. Ablation of atrial fibrillation: awaiting the new paradigm. J Am Coll Cardiol. 2003; 42(2):198-200.
9. Falk RH, Management of atrial fibrillation—radical reform or modest modification? NEJM. 2002; 347(23): 1883-1884.
10. Finta B, Haines DE. Catheter ablation therapy for atrial fibrillation. Cardiol Clin. 2004. 22(1):127-145, ix.
11. Friedman PL. Catheter cryoablation of cardiac arrhythmias. Curr Opin Cardiol. 2005; 20(1):48-54.
12. Friedman PL, Dubuc M, Green MS, et al. Catheter cryoablation of supraventricular tachycardia: results of the multicenter prospective "frosty" trial. Heart Rhythm. 2004; 1(2):129-138.
13. Gaita F, Riccardi R, Caponi D, et al. Linear cryoablation of the left atrium versus pulmonary vein cryoisolation in patients with permanent atrial fibrillation and valvular heart disease: correlation of electroanatomic mapping and long-term clinical results. Circulation. 2005; 111(2):136-142.
14. Gillinov AM, McCarthy PM. Advances in the surgical treatment of atrial fibrillation. Cardiol Clin. 2004; 22(1):147-157.
15. Herweg B, Sichrovsky T, Polosajian L, et al. Anatomic substrate, procedural results, and clinical outcome of ultrasound-guided left atrial-pulmonary vein disconnection for treatment of atrial fibrillation. Am J Cardiol. 2005; 95(7):871-875.
16. Hoyt RH, Wood M, Daoud E, et al. Transvenous catheter cryoablation for treatment of atrial fibrillation: results of a feasibility study. Pacing Clin Electrophysiol. 2005; 28(Suppl 1):S78-S82.
17. Jahangiri M, Weir G, Mandal K, et al. Current strategies in the management of atrial fibrillation. Ann Thorac Surg. 2006; 82(1):357-364.
18. John RM, Michaud G. Atrial fibrillation: nonpharmacologic therapies coming of age. Chest. 2004; 125(6):1977-1979.
19. Kay GN, Ellenbogen KA, Giudici M, et al. APT Investigators. The Ablate and Pace Trial: a prospective study of catheter ablation of the AV conduction system and permanent pacemaker implantation for treatment of atrial fibrillation. J Interv Card Electrophysiol. 1998; 2(2):121-135.
20. Lee MA, Weachter R, Pollak S, et al. The effect of atrial pacing therapies on atrial tachyarrhythmia burden and frequency: results of a randomized trial in patients with bradycardia and atrial tachyarrhythmias. J Am Coll Cardiol. 2003; 41(11):1926-1932.
21. Lemery R, Guiraudon G. Catheter and surgical ablation strategies in atrial fibrillation: what have we learned? Curr Opin Cardiol. 2005; 20(1):26-30.
22. Mack CA, Milla F, Ko W, et al. Surgical treatment of atrial fibrillation using argon-based cryoablation during concomitant cardiac procedures. Circulation. 2005; 112(9 Suppl):I1-6.
23. Oral H, Chugh A, Good E, et al. a tailored approach to catheter ablation of paroxysmal atrial fibrillation. Circulation. 2006; 113(15):1824-1831.
24. Oral H, Knight BP, Tada H, et al. Pulmonary vein isolation for paroxysmal and persistent atrial fibrillation. Circulation. 2002; 105(9):1077-1081.
25. Oral H, Pappone C, Chugh A, et al. Circumferential pulmonary-vein ablation for chronic atrial fibrillation. N Engl J Med. 2006; 354(9):934-941.
26. Oral H, Scharf C, Chugh A, et al. Catheter ablation for paroxysmal atrial fibrillation: segmental pulmonary vein ostial ablation versus left atrial ablation. Circulation. 2003; 108(19):2355-2360.
27. Pappone C, Augello G, Sala S, et al. A randomized trial of circumferential pulmonary vein ablation versus antiarrhythmic drug therapy in paroxysmal atrial fibrillation. J Am Coll Cardiol. 2006; 48(11):2340-2347.
28. Pappone C, Rosanio S, Augello G, et al. Mortality, morbidity, and quality of life after circumferential pulmonary vein ablation for atrial fibrillation: outcomes from a controlled nonrandomized long-term study. J Am Coll Cardiol. 2003; 42(2):185-197.
29. Pappone C, Santinelli V, Manguso F, et al. Pulmonary vein denervation enhances long-term benefit after circumferential ablation for paroxysmal atrial fibrillation. Circulation. 2004; 109(3):327-334.
30. Purerfellner H, Martinek M, Aichinger J, et al. Quality of life restored to normal in patients with atrial fibrillation after pulmonary vein ostial isolation. Am Heart J. 2004; 148(2):318-325.
31. Rosanio S, Ware DL, Saeed M. Pulmonary vein ablation of atrial fibrillation: beyond the traditional. Am J Med Sci. 2004; 328(6):323-329.
32. Saad EB, Rossillo A, Saad CP, et al. Pulmonary vein stenosis after radiofrequency ablation of atrial fibrillation: functional characterization, evolution, and influence of the ablation strategy. Circulation. 2003; 108(25):3102-3107.
33. Stabile G, Bertaglia E, Senatore G, et al. Catheter ablation treatment in patients with drug-refractory atrial fibrillation: a prospective, multi-centre, randomized, controlled study (Catheter Ablation For The Cure Of Atrial Fibrillation Study). Eur Heart J. 2006; 27(2):216-221.
34. Stabile G, Turco P, LaRocca V, et al. Is pulmonary vein isolation necessary for curing atrial fibrillation? Circulation. 2003; 108(6):657-660.
35. Van Gelder IC, Hagens VE, Bosker HA, et al. Rate Control versus Electrical Cardioversion for Persistent Atrial Fibrillation Study Group. A comparison of rate control and rhythm control in patients with recurrent persistent atrial fibrillation. N Engl J Med. 2002; 347(23):1834-1840.
36. Verma A, Natale A. Should atrial fibrillation ablation be considered first-line therapy for some patients? Why atrial fibrillation ablation should be considered first-line therapy for some patients. Circulation. 2005; 112(8):1214-1222.
37. Wazni OM, Marrouche NF, Martin DO, et al. Radiofrequency ablation vs antiarrhythmic drugs as first-line treatment of symptomatic atrial fibrillation: a randomized trial. JAMA. 2005:293(21):2634-2640.
38. Weerasooriya R, Jais P, Hocini M, et al. Effect of catheter ablation on quality of life of patients with paroxysmal atrial fibrillation. Heart Rhythm. 2005; 2(6):619-623.
39. Wood MA, Ellenbogen KA. Catheter ablation of chronic atrial fibrillation—the gap between promise and practice. N Engl J Med. 2006; 354(9):967-969.
40. Wyse DG, Waldo AL, DiMarco JP, et al. AFFIRM Investigators. A comparison of rate control and rhythm control in patients with atrial fibrillation. N Engl J Med. 2002; 347(23):1825-1833.
41. Yiu KH, Lau CP, Lee KL, Tse HF. Emerging energy sources for catheter ablation of atrial fibrillation. J Cardiovasc Electrophysiol. 2006; 17(Suppl 3):S56-S61.

Government Agency, Medical Society, and Other Authoritative Publications:

1. Blue Cross Blue Shield Association. Pulmonary Vein Isolation for Treatment of Atrial Fibrillation. TEC Assessment, 2006; 21(1).
2. Calkins H, Brugada J, Packer DL, et al. HRS/EHRA/ECAS expert Consensus Statement on catheter and surgical ablation of atrial fibrillation: recommendations for personnel, policy, procedures and follow-up. A report of the Heart Rhythm Society (HRS) Task Force on Catheter and surgical ablation of atrial fibrillation. Heart Rhythm. 2007; 4(6):816-661.
3. Fuster V, Ryden LE, Cannom DS, et al. ACC/AHA/ESC 2006 guidelines for the management of patients with atrial fibrillation: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines and the European Society of Cardiology Committee for Practice Guidelines (Writing Committee to Revise the 2001 Guidelines for the Management of Patients With Atrial Fibrillation). J Am Coll Cardiol. 2006; 48:e149-e246. Available at: http://www.acc.org/qualityandscience/clinical/guidelines/atrial_fib/pdfs/AF_Full_Text.pdf. Accessed on July 30, 2009.

Atrial Fibrillation
Cryoablation
Pulmonary Vein Ablation for Atrial Fibrillation
Radiofrequency Ablation