Right ventricular function in adults with repaired tetralogy of Fallot assessed with cardiovascular magnetic resonance imaging: detrimental role of right ventricular outflow aneurysms or akinesia and adverse right-to-left ventricular interaction

Abstract

Objectives: We examined the relationship among biventricular hemodynamics, pulmonary regurgitant fraction (PRF), right ventricular outflow tract (RVOT) aneurysm or akinesia, and baseline and surgical characteristics in adults with repaired tetralogy of Fallot (rTOF).

Background: The precise relationship of pulmonary regurgitation with biventricular hemodynamics has been hampered by limitations of right ventricular (RV) imaging.

Methods: We assessed 85 consecutive adults with rTOF and 26 matched healthy controls using cardiovascular magnetic resonance imaging.

Results: Patients had higher right ventricular end-diastolic volume index (RVEDVi) (p < 0.001), right ventricular end-systolic volume index (RVESVi) (p < 0.001), right ventricular mass index (RVMi) (p < 0.001), and lower right ventricular ejection fraction (RVEF) (p < 0.001) and left ventricular ejection fraction (LVEF) (p = 0.002) compared to controls. The PRF (range 0% to 55%) independently predicted RVEDVi (p < 0.01) and the latter predicted RVESVi (p < 0.01) and RVMi (p < 0.01). The RVOT aneurysm/akinesia was present in 48/85 (56.9%) of patients and predicted RV volumes (RVEDVi, p = 0.01, and RVESVi, p = 0.03). There was a negative effect of RVOT aneurysm/akinesia and RVMi on RVEF (p < 0.01 and p = 0.02, respectively). There was only a tendency among patients with transannular or RVOT patching toward RVOT aneurysm/akinesia (p = 0.09). The LVEF correlated with RVEF (r = 0.67, p < 0.001).

Conclusions: Pulmonary regurgitation and RVOT aneurysm/akinesia were independently associated with RV dilation and the latter with RV hypertrophy late after rTOF. The RVOT aneurysm/akinesia was common but related only in part to RVOT or transannular patching. Both RV hypertrophy and RVOT aneurysm/akinesia were associated with lower RVEF. Left ventricular systolic dysfunction correlated with RV dysfunction, suggesting an unfavorable ventricular-ventricular interaction. Measures to maintain or restore pulmonary valve function and avoid RVOT aneurysm/akinesia are mandatory for preserving biventricular function late after rTOF.