Aetna Maze Procedure Coverage Update

Coverage Summary

Scope: This policy defines Aetna's coverage positions for Maze procedures for atrial fibrillation/flutter, specifying that Maze procedures performed with cardiopulmonary bypass on a beating heart (Cox-Maze variants) are considered medically necessary when specified criteria are met, whereas minimally invasive, off-pump Maze procedures (including hybrid and Convergent hybrid procedures) are considered experimental and investigational and are not covered. The scope also lists applicable CPT and ICD-10 codes for covered and not-covered approaches.

Concomitant procedures and exclusions: Aetna considers concomitant Maze and septal myectomy medically necessary for treatment of hypertrophic obstructive cardiomyopathy plus refractory atrial fibrillation/flutter. Off-pump, minimally invasive, hybrid and Convergent approaches are explicitly listed as experimental and investigational (not medically necessary). The policy provides CPT codes covered if criteria are met (e.g., 33254, 33256, 33257, 33259, 33416) and codes not covered for listed indications (e.g., 33255, 33258, 33265, 33266), plus related CPT and ICD-10 diagnosis codes.

Dates: Policy effective date is 1998-03-31; last review date is 2023-03-29; next review date is 2024-02-22.

Medical-Necessity Criteria

Medical Necessity

Aetna considers the Maze procedure, performed with cardiopulmonary bypass on a beating heart, medically necessary for members with atrial fibrillation/flutter when ANY of the following are met:

ANY of the following

ALL of the following
- Member cannot tolerate the side effects of drug therapy (adequate documentation of the nature and extent of the intolerance is required).
- Member is suffering the hemodynamic consequences of chronic atrial fibrillation/flutter despite adequate attempts at medical management.
- High-risk for thromboembolism
  - Either
    A previous episode of thromboembolism when other sources of emboli have been ruled out.
    Documented long-standing atrial fibrillation in members with mitral valve disease undergoing open surgical repair of the mitral valve.

Concomitant Procedures - Medically Necessary

Concomitant Maze and septal myectomy:

Concomitant Maze and septal myectomy is medically necessary for treatment of hypertrophic obstructive cardiomyopathy plus refractory atrial fibrillation/flutter.

Experimental, Investigational, and Not Medically Necessary

Post-operative routine testing: As noted in the policy background, a variety of post-operative tests are typically used to evaluate atrial status, but unless clinically indicated by the member's signs and symptoms these tests are considered not routinely medically necessary. Examples include endocardial catheter electrophysiology study, 24-hour Holter monitor, exercise stress test, and color-flow Doppler evaluation of transmitral and transtricuspid valve flow.

Coding

CPT codes covered if selection criteria are metCPTCovered

33254	Operative tissue ablation and reconstruction of atria, limited (e.g., modified maze procedure).
33256	Operative tissue ablation and reconstruction of atria, extensive (eg, maze procedure); with cardiopulmonary bypass.
33257	Operative tissue ablation and reconstruction of atria, performed at the time of other cardiac procedure(s), limited (e.g., modified maze procedure) (List separately in addition to code for primary procedure).
33259	Operative tissue ablation and reconstruction of atria, performed at the time of other cardiac procedure(s), extensive (e.g., maze procedure), with cardiopulmonary bypass (List separately in addition to code for primary procedure).
33416	Ventriculomyotomy (-myectomy) for idiopathic hypertrophic subaortic stenosis (eg, asymmetric septal hypertrophy).

CPT codes not covered for indications listed in the CPBCPTNot Covered

33255	Operative tissue ablation and reconstruction of atria, extensive (e.g., maze procedure); without cardiopulmonary bypass [hybrid Maze procedure].
33258	Operative tissue ablation and reconstruction of atria, performed at the time of other cardiac procedure(s), extensive (e.g., maze procedure), without cardiopulmonary bypass (List separately in addition to code for primary procedure) [hybrid Maze procedure].
33265	Endoscopy, surgical; operative tissue ablation and reconstruction of atria, limited (e.g., modified maze procedure), without cardiopulmonary bypass.
33266	Operative tissue ablation and reconstruction of atria, extensive (e.g., maze procedure), without cardiopulmonary bypass.

Other CPT/related CPT codes (listed as related to CPB)CPT

62303-62305	Myelography via lumbar injection, including radiological supervision and interpretation.
93015	Cardiovascular stress test using maximal or submaximal treadmill or bicycle exercise, continuous electrocardiographic monitoring, and/or pharmacological stress; with physician supervision, with interpretation and report.
93224-93227	Electrocardiographic monitoring for 24 hours.
93600-93660	Intracardiac electrophysiological procedures/studies.

ICD-10 diagnosis codes covered if selection criteria are metICD-10Covered

I42.1	Obstructive hypertrophic cardiomyopathy.
I48.0	Atrial fibrillation [chronic].
I48.1	Atrial flutter [chronic].

Provider Actions

Prior Authorization

Coverage limited to on-pump procedures

Coverage limited to Maze procedures performed with cardiopulmonary bypass on a beating heart. Off-pump, minimally invasive, hybrid, and Convergent Maze procedures are considered experimental/investigational and are not covered.

Affected CPT codes: 33256, 33259, 33254, 33257
Off-pump/minimally invasive/hybrid/Convergent Maze procedures are not covered

Documentation Required

Document drug intolerance

When using 'cannot tolerate side effects of drug therapy' as an indication for the Maze procedure, provide adequate documentation of the nature and extent of the drug intolerance.

Documentation Required

Background and Evidence Summary

Cox-Maze and surgical approaches: The Cox-Maze procedure (cut-and-sew and energy-based variants such as Cox-Maze IV) is described as a surgical treatment that creates multiple atrial lesions to interrupt reentrant circuits, addressing both hemodynamic consequences of AF and thromboembolism risk; the Cox-Maze remains the gold standard with excellent long-term efficacy. The background notes that alternative energy sources (radiofrequency, cryoablation) have produced similar conversion rates in some reviews.

Minimally invasive and off-pump approaches: Thoracoscopic off-pump (TOP) or "mini-maze" procedures are performed on the beating heart using epicardial radiofrequency via thoracoscopy and aim to be less invasive; early systematic reviews and series show variable success and evolving techniques but evidence — particularly randomized long-term outcomes — is limited. Some analyses report promising short-term efficacy but also higher or variable complication rates versus catheter ablation or on-pump Cox-Maze.

Hybrid and Convergent procedures and trials: Hybrid epicardial–endocardial approaches, including the Hybrid Convergent procedure, combine surgical epicardial and catheter endocardial ablation to achieve transmural lesion sets. The randomized CONVERGE trial (n=153) found superior effectiveness of Hybrid Convergent versus catheter ablation for persistent/long-standing persistent AF at 12 months (67.7% vs 50.0% on/off AADs; 53.5% vs 32.0% off AADs) with acceptable 30-day safety events. Overall, hybrid techniques show promising efficacy in selected studies/registries but are evolving and have variable complication profiles. The policy reiterates that minimally invasive, off-pump, hybrid and Convergent procedures are considered experimental/investigational for the policy's coverage purposes.

Study / Source	Key result
Krul et al (2013)	Single-procedure success at 1 year: 69% without AAD (95% CI 58–78%) and 79% with AAD (95% CI 71–85%).
FAST trial (UpToDate summary)	At 12 months surgical ablation had higher freedom from arrhythmia (65.6% vs 36.5%) but more peri-procedural complications (35.4% vs 15.9%).
CONVERGE trial (DeLurgio et al 2020)	Primary effectiveness at 12 months: Hybrid Convergent 67.7% vs catheter ablation 50.0% (p=0.036) on/off AADs; off AADs 53.5% vs 32.0% (p=0.0128).
CONVERGE 18-month results (DeLurgio et al 2020)	>=90% AF burden reduction at 18 months: Hybrid 74.0% vs CA 55%.
CONVERGE safety (DeLurgio et al 2020)	Primary safety events: 2.9% within 7 days and 4.9% between 8–30 days; no deaths, cardiac perforations, or atrio-esophageal fistulas.
Eranki et al (2022) meta-analysis	HCA associated with higher freedom from AF (OR 2.78; 95% CI 1.82–4.24) but more major complications (OR 5.14; 95% CI 1.70–15.54).
Van der Heijden RCT (2023)	Freedom from atrial tachyarrhythmia >5 min off AADs at 12 months: Hybrid ablation 89% vs catheter ablation 41% (p=0.002); serious AEs comparable.
Dunnington heart-team hybrid cohort (n=455)	Freedom from AF (FFAF) at 3, 12, 24, 36 months: 92%, 87%, 81%, 72%; any surgical complications 6.1%.
Kress et al (2017) comparative cohort	In persistent AF, hybrid ablation had lower recurrence (37% vs 58%), fewer repeat ablations (9% vs 26%), and AF-free survival 72% vs 51% vs endocardial ablation.
Khan et al (2020) review of Convergent	Selected series: at 12 months 81.9% in sinus rhythm (overall CVP), 54.1% off AADs; overall complication rate ~10%.

Hybrid Convergent (HC/HCA/CVP/HA): A combined epicardial (surgical, often subxiphoid) and endocardial catheter ablation approach intended to achieve transmural lesion sets for treatment of persistent/long-standing persistent AF.

Cox-Maze IV (CMIV): A surgical maze procedure using energy-based ablation lines (versus cut-and-sew) considered a gold standard surgical ablation for atrial fibrillation.

Revision History

1998-03-31policy_effective

Policy effective date

2023-03-29last_reviewLatest

Most recent policy review

2024-02-22next_review

Scheduled next policy review