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/m(2) to 138 ± 34 ml/m(2); 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/m(2)/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/m(2)/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.
Keywords: Exercise capacity; Long-term outcome; Magnetic resonance imaging; Serial follow-up; Tetralogy of Fallot.
© 2013.