Long-term follow-up of cardiopulmonary function and cardioechographic examinations in patients with repaired tetralogy of Fallot

Background

Tetralogy of Fallot (TOF) is one of the most common cyanotic congenital heart defects and typically requires intracardiac repair to correct cardiac anomalies. Postoperative TOF patients have compromised exercise capacity, which tends to decline over time. We assessed cardiopulmonary function using serial exercise testing and echocardiographic findings from childhood to adolescence in patients with repaired TOF.

Methods

This was a retrospective study. We recruited children with TOF who underwent at least two treadmill cardiopulmonary exercise tests (CPET) (with >1-year interval between the tests) between 2005 and 2022. Serial echocardiography results were evaluated to compare long-term changes in ejection fraction and pulmonary arterial pulse wave velocity. Healthy controls who underwent serial CPETs with intervals >1 year were also recruited.

Results

A total of 86 participants and 86 age-, sex-, and body mass index-matched healthy peers were identified. Significant decreases were observed in the CPET parameters between the initial and final CPETs, including peak VO₂% (p < 0.001), peak MET (p = 0.027), peak heart rate (p = 0.009), and MET at AT (p = 0.001). In comparison to the control group, the patient group exhibited inferior aerobic capacity in the initial CPET, characterized by smaller peak MET (p = 0.049), peak VO₂ (p = 0.001), and peak VO₂% (p < 0.001). Furthermore, a notable decline in exercise capacity was noted in the patient group during the follow-up. No significant differences were observed between the serial ejection fraction and pulmonary arterial pulse wave velocity.

Conclusions

Patients with repaired TOF had inferior exercise capacities to their healthy peers, and the peak exercise load capacities tended to decline over time. However, they were safe to engage in exercise training since the CPET results exceeded the standard for moderate-to-vigorous physical activity.