MR imaging of right ventricular function after the Ross procedure for aortic valve replacement: Initial experience

Purpose: To prospectively assess right ventricular (RV) function after the Ross procedure by using magnetic resonance (MR) imaging. Materials and Methods: The local ethics committee approved the study and informed consent was obtained from all participants prior to enrollment in the study. Seventeen patients (15 male, two female; mean age ± standard deviation, 19 years ± 3.9; imaging performed 8.3 years after surgery ± 3.2) and 17 matched controls (15 male, two female; mean age ± standard deviation, 20 years ± 3.9) were studied by using MR imaging. Standard velocity-encoded and multisection multiphase imaging sequences were used to assess homograft valve function, systolic and diastolic RV function, and RV mass. The two-tailed Mann-Whitney U test and the Spearman rank correlation coefficient were used for statistical analysis. Results: Minor degrees of homograft stenosis (peak flow velocity between 1.5 and 3.0 m/sec across the homograft valve) were found in 12 of 17 patients but not in controls (P < .001). A larger RV mass was present in Ross patients than in controls (17.0 g/m² ± 4.8 vs 10.9 g/m² ± 5.6, P = .004). In addition, impaired diastolic RV function was found, as shown by a decreased mean tricuspid valve early filling phase-atrial contraction phase (E/A) peak flow velocity ratio (1.56 ± 0.75 vs 2.05 ± 0.58, P = .03). Peak flow velocity across the homograft valve correlated with RV mass (r = 0.38, P = .03) and tricuspid valve E/A peak flow velocity ratio (r = 0.39, P = .02). RV systolic function was normal in Ross patients (mean RV ejection fraction, 52% ± 8 vs 51% ± 5; P = .74). Conclusion: RV hypertrophy and RV diastolic dysfunction are frequently observed in patients after the Ross procedure, even in the absence of overt homograft stenosis. RV systolic function is still preserved.