Long-term outcome of repaired tetralogy of Fallot: Survival, tachyarrhythmia, and impact of pulmonary valve replacement

Background

Pulmonary valve replacement (PVR) is recommended for severe pulmonary regurgitation in repaired tetralogy of Fallot (rTOF).

Objective

The purpose of this study was to investigate the event rate and effectiveness of PVR.

Methods

A retrospective study of tetralogy of Fallot patients who survived total repair from 1970 to 2020 was conducted.

Results

We identified 1744 rTOF patients; 86.6% with classic rTOF, 11.5% with pulmonary atresia, 0.8% with endocardial cushion defect, and 1.1% with absent pulmonary valve. Annual risks of tachyarrhythmia/sudden cardiac arrest (SCA) increased to 0.295% and 1.338% in patients aged 10–30 and 30–60 years, respectively, without sex predominance. PVR (223 surgical and 39 percutaneous) event rate was 34.7% ± 2.1% by 30 years after repair (annual risk: 1.57% between 10 and 30 years after repair). The second PVR rate was 9.9% ± 4.1% by 20 years after the first PVR. Tachyarrhythmia/SCA risk was higher in PVR patients than in No PVR patients and was reduced in PVR patients without tachyarrhythmia/SCA before PVR. However, survival in patients with ventricular tachyarrhythmia/SCA still was better after PVR. At PVR, 13% of patients had tachyarrhythmia/SCA, which was the major predictor of events after PVR. Before PVR, although the ventricular tachyarrhythmia/SCA risks included QRS duration >160 ms and New York Heart Association functional class III or IV, supraventricular tachyarrhythmia was associated with PVR age ≥28 years and N-terminal pro–brain natriuretic peptide >450 pg/mL.

Conclusion

Tachyarrhythmia/SCA occurrence and the need for PVR increased with age during young adulthood. PVR reduced subsequent arrhythmias only in those patients without arrhythmias before PVR.

Introduction

Tetralogy of Fallot (TOF) is the most common form of cyanotic congenital heart disease, with an incidence of 0.20–0.63 per 1000 live births.^1,2 The first cardiac repair of TOF was successfully performed in 1955 in the United States and in 1965 in Taiwan.^3,4 Advances in perioperative care have increased the survival rate after total correction to approximately 97%.^4,5 However, adverse cardiovascular effects, including progressive pulmonary regurgitation (PR), ventricular dysfunction, and tachyarrhythmia, may lead to high morbidity in later life and mortality. The incidence of severe PR in repaired tetralogy of Fallot (rTOF) may vary with outflow tract morphology and the surgical technique used to release pulmonary stenosis. By age 40 years, one-third of TOF patients had received a surgical pulmonary valve replacement (PVR) for PR with an annual PVR rate of 0.8%.^6,7 PVR is recommended for rTOF patients with symptoms or imaging evidence of right ventricular (RV) dysfunction.⁸ With the introduction of percutaneous PVR, patients with severe PR may be referred earlier for percutaneous PVR. PVR can improve symptoms secondary to severe PR, and beneficial RV reverse remodeling can be expected.⁹ However, PVR might not improve RV function or ameliorate the ventricular tachycardia risk.9, 10, 11 In a high-risk TOF cohort, appropriate shocks from an implantable cardioverter-defibrillator as a primary or secondary preventive method could be reduced after PVR.¹² Effects of PVR may be diverse among subgroups of rTOF with distinct clinical pictures. Therefore, we hypothesized that the potential protective action of PVR should be examined in patients stratified by tachyarrhythmia/SCA. Using a large institutional cohort and an extended observation period, we investigated time-dependent survival, tachyarrhythmia/sudden cardiac arrest (SCA), and PVR in rTOF patients to test our hypothesis.