Right ventricular function after pulmonary valve replacement in patients with tetralogy of Fallot

Abstract

Purpose: To assess the time course of right ventricular (RV) function improvement after pulmonary valve replacement (PVR) in patients 25.2 years +/- 7.0 after repair of tetralogy of Fallot.

Materials and methods: The medical ethics committee approved this study, and informed consent was obtained. Cardiac magnetic resonance (MR) imaging was performed before, 7 months after, and 19 months after PVR in 25 consecutive patients with tetralogy of Fallot with a 1.5-T MR imager. RV function was assessed with gradient-echo sequences in the short-axis plane. Pulmonary flow was assessed with a velocity-encoded phase-contrast sequence. Paired t test was used to evaluate follow-up data. Independent samples t test was used to assess differences based on the presence of recurrent pulmonary regurgitation (PR).

Results: Mean indexed RV end-diastolic volume decreased from 166.9 mL/m(2) +/- 41.3 before PVR to 113.5 mL/m(2)+/- 35.7 (P < .001) at 7-month follow-up and 111.7 mL/m(2)+/- 41.1 (P = .46) at 19-month follow-up. The RV ejection fraction was corrected for PR and improved from 25.0% +/- 7.7 before surgery to 44.1% +/- 11.9 (P < .001) and 45.2% +/- 11.1 (P = .39), at 7- and 19-month follow-up, respectively. Recurrent PR after PVR was found in 11 patients; 14 patients did not have recurrent PR. Total reduction of indexed RV end-diastolic volume at 19 months follow-up was more prominent in patients who did not have recurrent PR than in patients who did have recurrent PR (P < .05). Furthermore, improvement of RV ejection fraction corrected for regurgitation was more marked in patients who did not have recurrent PR than in patients who did have recurrent PR (P < .05).

Conclusion: In patients with tetralogy of Fallot, RV function improves rapidly after PVR and is sustained at 19-month follow-up in most patients; however, recurrence of PR after PVR appears to reduce recovery of RV systolic function.