What are the late-life complications of Tetralogy of Fallot (TOF)?

From the Guidelines

Tetralogy of Fallot survivors are at risk for several late-life complications, including arrhythmias, pulmonary valve regurgitation, heart failure, and exercise intolerance, which can be managed with antiarrhythmic medications, pulmonary valve replacement, standard heart failure therapies, and cardiac rehabilitation programs, as recommended by the 2018 AHA/ACC guideline for the management of adults with congenital heart disease 1.

Late-Life Complications

Tetralogy of Fallot survivors can experience several late-life complications even after successful repair, including:

• Arrhythmias, particularly ventricular tachycardia and atrial fibrillation, which may require antiarrhythmic medications like amiodarone or sotalol, or procedural interventions such as ablation or implantable cardioverter-defibrillator placement, as recommended by the 2017 AHA/ACC/HRS guideline for management of patients with ventricular arrhythmias and the prevention of sudden cardiac death 1
• Pulmonary valve regurgitation, which often develops over time, leading to right ventricular dilation and dysfunction, and may necessitate pulmonary valve replacement when symptoms develop or when right ventricular end-diastolic volume exceeds 160-170 mL/m², as recommended by the ACC/AHA 2008 guidelines for the management of adults with congenital heart disease 1
• Heart failure, which can occur due to right ventricular dysfunction or biventricular failure, requiring standard heart failure therapies including ACE inhibitors, beta-blockers, and diuretics
• Exercise intolerance, which is common, with patients benefiting from cardiac rehabilitation programs and appropriate exercise prescriptions

Management and Prevention

The management and prevention of these complications involve:

• Lifelong cardiology follow-up to monitor for signs of complications and to provide timely interventions
• Antibiotic prophylaxis for dental procedures according to current guidelines to prevent endocarditis
• Monitoring for aortic root dilation and potential surgical intervention if the diameter exceeds 5.0-5.5 cm
• Collaboration between ACHD surgeons and ACHD interventional cardiologists to determine the most feasible treatment for pulmonary artery stenosis, as recommended by the ACC/AHA 2008 guidelines for the management of adults with congenital heart disease 1

Key Recommendations

Pulmonary valve replacement is reasonable in adults with previous tetralogy of Fallot, severe pulmonary regurgitation, and any of the following: moderate to severe RV dysfunction, moderate to severe RV enlargement, development of symptomatic or sustained atrial and/or ventricular arrhythmias, or moderate to severe TR, as recommended by the ACC/AHA 2008 guidelines for the management of adults with congenital heart disease 1. The 2018 AHA/ACC guideline for the management of adults with congenital heart disease also recommends that adults with repaired tetralogy of Fallot physiology and inducible VT/VF or spontaneous sustained VT should undergo implantation of an ICD if meaningful survival greater than 1 year is expected 1.

From the Research

Late Life Complications of Tetralogy of Fallot

• Pulmonary regurgitation (PR) is a common late complication of Tetralogy of Fallot (TOF), which can lead to right ventricular (RV) dysfunction and arrhythmias 2, 3, 4.
• Right ventricular tract obstruction, residual shunts, and RV dysfunction are also potential late complications of TOF 2.
• Arrhythmias, including ventricular tachycardia, are a significant concern in patients with repaired TOF, and can increase the risk of sudden cardiac death 5, 4.
• Pulmonary valve replacement is often necessary to address pulmonary regurgitation and other complications, but the optimal timing of this procedure is challenging to determine 2, 4.

Role of Cardiac Imaging in Monitoring TOF Patients

• Cardiac magnetic resonance (CMR) imaging is a valuable tool for assessing cardiac function and monitoring disease progression in patients with repaired TOF 3, 6.
• CMR can provide accurate measurements of ventricular size, ejection fraction, and valvular regurgitation, and can help identify patients at risk of late complications 3, 6.
• Other imaging modalities, such as echocardiography and computer tomography (CT), may also be used to monitor TOF patients, but CMR is considered the gold standard for assessing cardiac function 2.

Predictors of Disease Progression in TOF Patients

• Impaired right and left ventricular function are consistent independent predictors of disease progression in repaired TOF 6.
• Other factors, such as QRS duration and older age at repair, may also be associated with disease progression 6.
• The optimal timing of repeat cardiac imaging remains controversial, and large-scale prospective studies are needed to guide clinical decision making in this area 6.