Top Things to Know: Long-Term Management of Right Ventricular Outflow Tract Dysfunction in Repaired Tetralogy of Fallot
Published: November 21, 2024
- Tetralogy of Fallot (TOF) is the fifth most common form of congenital heart disease and the most encountered cyanotic lesion. Contemporary early survival following infant surgery is approximately 98% with 25-year survival of over 90%.
- Surgical reconstruction of the right ventricular outflow tract (RVOT) during TOF repair (rTOF) often results in pulmonary regurgitation, stenosis, or both. These anatomic and functional derangements trigger a complex, slowly progressive pathophysiologic cascade that ultimately results in adverse clinical outcomes, including heart failure, arrhythmias, and premature death.
- Risk stratification in rTOF is guided by clinical characteristics (age, obesity), type of primary surgical repair (transannular patch or conduit), exercise testing parameters, and imaging biomarkers. Emerging data suggest that risk stratification can be further refined through the application of validated risk scores and facilitated through the application of artificial intelligence algorithms.
- Routine surveillance testing including ECG, echocardiogram, cardiopulmonary exercise testing, and cardiac MRI are performed regularly in patients with rTOF. Additional testing via Holter, bloodwork, CT, or cardiac catheterization may be considered as directed by clinical data and candidacy for transcatheter or surgical intervention.
- Surgical pulmonary valve replacement (PVR) is relatively safe. Selection of the optimal surgical prosthesis ought to be individualized based on patient characteristics, availability, and overall lifelong strategy for minimizing the number of invasive procedures.
- Transcatheter PVR was initially performed mostly in patients with right ventricle-to-pulmonary artery conduits and previously implanted bioprosthetic pulmonary valves. With the introduction of large diameter valves and self-expanding prostheses designed expressly for patients with patched RVOT anatomy, the use of TPVR has evolved as a viable alternative to surgical PVR with promising early results.
- A coordinated approach between surgeons and interventionalists that includes the use of both surgical and transcatheter valves throughout the patient’s lifetime likely provides the optimal strategy to reduce long-term morbidity.
- Updated evidence-based criteria for PVR comprise of risk factors for morbidity and mortality, including INDICATOR risk score ≥3, reduced right or left ventricular ejection fraction, reduced peak oxygen consumption by exercise testing, and right ventricular hypertension. Additional criteria include symptoms, sustained ventricular tachycardia, and presence of residual lesions.
- For patients with rTOF, sustained monomorphic ventricular tachycardia is increasingly observed with age and is associated with sudden cardiac death. In most cases, the underlying substrate is diseased myocardium within the RVOT that can be successfully treated by catheter ablation prior to transcatheter PVR or direct intraoperative cryoablation at surgical PVR.
- Long-term surveillance of patients with rTOF is critical to anticipate and proactively manage complications. Multimodality testing is recommended periodically, and its frequency is tailored to symptoms and severity of illness.
Citation
Geva T, Wald RM, Bucholz E, Cnota JF, McElhinney DB, Mercer-Rosa LM, Mery CM, Miles AL, Moore J; on behalf of the American Heart Association Council on Lifelong Congenital Heart Disease and Heart Health in the Young; Council on Cardiovascular Surgery and Anesthesia; Council on Clinical Cardiology; and Council on Cardiovascular and Stroke Nursing. Long-term management of right ventricular outflow tract dysfunction in repaired tetralogy ofFallot: a scientific statement from the American Heart Association. Circulation. Published online November 21, 2024. doi: 10.1161/CIR.0000000000001291