What are the criteria for surgery in patients with Ebstein's anomaly?

Surgical Criteria for Ebstein's Anomaly

Surgical repair or reoperation for adults with Ebstein anomaly and significant tricuspid regurgitation is recommended when one or more of the following are present: heart failure symptoms, objective evidence of worsening exercise capacity, or progressive right ventricular systolic dysfunction by echocardiography or CMR. 1

Class I (Definitive) Indications for Surgery

The 2018 AHA/ACC guidelines provide the strongest evidence-based criteria for surgical intervention 1, 2, 3:

Primary Indications (Must Have Significant TR Plus ≥1 of):

• Heart failure symptoms (any NYHA class with symptoms)
• Objective evidence of worsening exercise capacity (documented on formal exercise testing)
• Progressive RV systolic dysfunction (by echo or CMR)

Additional Class I Indications:

• Cyanosis (oxygen saturation <90%) 4
• Paradoxical embolism (documented event) 4

Class IIa (Reasonable) Indications for Surgery

Surgery can be beneficial in patients with significant TR when the following are present 1, 3:

• Progressive RV enlargement (even without overt dysfunction)
• Systemic desaturation from right-to-left atrial shunt
• Atrial tachyarrhythmias (refractory to medical/catheter management)

Key Preoperative Assessment Requirements

Before determining surgical candidacy, comprehensive evaluation must include 1:

Imaging Studies:

• CMR imaging is the gold standard for determining RV dimensions and systolic function (Class IIa recommendation)
• TEE for surgical planning if TTE images inadequate for valve morphology assessment
• Objective exercise testing (cardiopulmonary exercise test or 6-minute walk) to unmask occult exercise intolerance in subjectively asymptomatic patients 5

Electrophysiology Evaluation:

• Electrophysiology study (with catheter ablation if needed) is reasonable before surgical intervention even in the absence of preexcitation or supraventricular tachycardia 1
• This addresses the high prevalence of accessory pathways in Ebstein anomaly

Important Clinical Nuances

Asymptomatic Patients:

The newest AATS 2025 consensus 5 suggests surgery can be beneficial in asymptomatic patients with:

• Severe tricuspid regurgitation
• Moderate RV enlargement
• Valve anatomy favorable for repair

This represents a shift toward earlier intervention before irreversible RV dysfunction develops.

Progressive Cardiomegaly:

Progressive cardiomegaly on chest x-ray is an established surgical indication 4, as it reflects worsening RV dilation and functional deterioration.

Risk Stratification Factors:

Recent data 6 identifies preoperative hepatic congestion, Wolff-Parkinson-White syndrome, and elevated ALT as independent risk factors for adverse outcomes, suggesting these patients may benefit from earlier intervention.

Adjunctive Surgical Procedures

Bidirectional Glenn (Cavopulmonary) Anastomosis:

May be considered (Class IIb) at time of repair when 1:

• Severe RV dilation present
• Severe RV systolic dysfunction present
• LV function preserved
• Left atrial and LV end-diastolic pressures not elevated

The AATS 2025 guidelines 5 strengthen this recommendation, stating Glenn is reasonable when RA:LA pressure ratio >1.5 or failure to separate from cardiopulmonary bypass after repair.

Arrhythmia Surgery:

• Concomitant Maze procedure is reasonable for paroxysmal or continuous atrial fibrillation 5
• Catheter ablation is recommended (Class I) for high-risk pathway conduction or multiple accessory pathways 1

Critical Pitfalls to Avoid

1. Don't rely solely on subjective symptoms: Exercise testing frequently reveals objective exercise intolerance in patients who report being asymptomatic 5. Formal cardiopulmonary exercise testing should be performed.

2. Don't wait for severe RV dysfunction: The evidence increasingly supports earlier intervention. Once severe RV dysfunction develops, surgical outcomes worsen significantly 7. RV fractional shortening <20% is associated with dramatically worse survival.

3. Don't overlook left ventricular dysfunction: LV ejection fraction correlates with survival 7. When LV dysfunction is present (EF <30%), heart transplantation should be considered rather than valve surgery alone 4.

4. Don't ignore hepatic congestion: This is an independent predictor of poor outcomes 6 and should prompt consideration for earlier surgery.

Timing Considerations

The optimal timing balances intervention before irreversible RV remodeling occurs while avoiding unnecessary surgery in stable patients. The algorithm is:

1. Symptomatic patients with significant TR → Surgery (Class I)
2. Asymptomatic with objective exercise limitation → Surgery (Class I)
3. Asymptomatic with progressive RV dysfunction/enlargement → Surgery (Class IIa)
4. Asymptomatic with severe TR, moderate RV enlargement, favorable anatomy → Consider surgery (per AATS 2025) 5

The evidence strongly suggests that waiting for severe symptoms or advanced RV dysfunction results in worse outcomes, supporting a more proactive surgical approach in appropriately selected patients.