5-year serial follow-up of clinical condition and ventricular function in patients after repair of tetralogy of Fallot

Objective

To study the changes over time in biventricular size and function, and clinical parameters in patients after repair of tetralogy of Fallot (TOF) without subsequent pulmonary valve replacement (PVR).

Methods

We prospectively included 78 non-PVR patients (age 20(6–60)years at baseline), who were studied twice with a 5-year interval. Patients underwent magnetic resonance imaging for assessment of biventricular size and function. Exercise testing and electrocardiography were performed to determine peak oxygen uptake (peak VO₂) and QRS duration. N-terminal prohormone brain natriuretic peptide (NT-proBNP) was assessed additionally.

Results

Pulmonary regurgitation (PR), right ventricular (RV) volumes and QRS duration increased during 5-year follow-up (RV end-diastolic volume (EDV) 130 ± 30 ml/m² to 138 ± 34 ml/m²; QRS 132 ± 27 msec to 139 ± 27 msec); peak VO₂ decreased (96 ± 19% to 91 ± 17%). RV ejection fraction, RV effective stroke volume (eff.SV), and NT-proBNP levels remained unchanged. The slope of RVEDV increase was 1.6 ± 3.0 ml/m²/year, and depended on RVeff.SV, not on RVEDV, at baseline. Increase in RVEDV correlated with increase in QRS duration over time (r = 0.28, p = 0.016), and with decrease in RV mass/EDV ratio over time (r = − 0.42, p < 0.001), not with decrease in peak VO₂. In subgroup analysis, patients with larger RVs at baseline showed larger increase in PR during follow-up and larger decrease in NYHA class over time.

Conclusions

In TOF patients with moderate RV dilatation, RVEDV increased by 1.6 ± 3.0 ml/m²/year, irrespective of RV size at baseline, but depended on RVeff.SV at baseline. Despite limited progression in RV size, unfavourable changes occurred during 5 years follow-up, which suggests there is a need for close follow-up.