Right ventricular outflow tract obstruction as a confounding factor in the assessment of the impact of pulmonary regurgitation on the right ventricular size and function in patients after repair of tetralogy of fallot

Abstract

Purpose: To compare right ventricular (RV) size and function between patients with combined pulmonary regurgitation (PR) plus RV outflow tract (RVOT) obstruction (RVOTO) and patients with isolated PR. Materials and Methods:Consecutive individuals with significant PR (PR fraction !20%) after tetralogy of Fallot (TOF) repair who underwent cardiovascular magnetic resonance (CMR) were included. Patients with additional hemodynamic abnormalities (residual ventricular septal defect, extracardiac shunt, and/or more than mild regurgitation at a valve other than the pulmonary valve) were excluded. Significant RVOTO was defined as peak gradient across RVOT !30 mmHg.Results: Significant differences between patients with combined PRþRVOTO (n ¼ 9) and isolated PR (n ¼ 33) were observed in RV end-diastolic volume (138.6 6 25.1 vs. 167.0 6 34.6 mL/m 2 , P ¼ 0.02, respectively), RV endsystolic volume (65.0 6 9.6 vs. 92.7 6 26.2 mL/m 2 , P ¼ 0.003), and RV ejection fraction (RVEF) (52.8 6 3.7 vs. 45.0 6 6.4%, P ¼ 0.001). Both PR and peak RVOT gradient were independent predictors of RV size. Conclusion:Patients with combined PRþRVOTO had smaller RV volumes and higher RVEF when compared with patients with isolated PR. The confounding effect of RVOTO on RV size and function needs to be considered in CMR studies evaluating patients after TOF repair.

Longitudinal Validation of the Diastolic to Systolic Time–Velocity Integral Ratio as a Doppler-Derived Measure of Pulmonary Regurgitation in Patients with Repaired Tetralogy of Fallot

“…Similarly to our findings, a previous study in patients with repaired TOF found no differences in regurgitant fraction between those with and without RVOT obstruction. 21 …”

Determinants of left- and right‑ventricular ejection fractions in patients with repaired tetralogy of Fallot: a cardiac magnetic resonance imaging study

“…Selected data on patients with repaired TOF undergoing CMR imaging study in our center were published previously. [9][10][11][12] In particular, we previously analyzed factors associated with biventricular dysfunction in the same study population (31 patients with biventricular dysfunction and 65 patients with normal biventricular systolic functions were selected out of a group of 146 patient; unpublished data).…”

“…Nevertheless, we and other investigators have previously demonstrated that patients after TOF repair with coexisting RVOT obstruction (including branch pulmonary stenosis) had lower RVEDV compared with patients without obstruction. 11,33 Moreover, those with significant PR and concomitant RVOT obstruction (including but not limited to branch pulmonary stenosis) had higher RVEF in comparison with patients with isolated PR. 11 The relationship between various types and severity degrees of RVOT obstruction and ventricular function should be adequately addressed in further studies.…”

“…11,33 Moreover, those with significant PR and concomitant RVOT obstruction (including but not limited to branch pulmonary stenosis) had higher RVEF in comparison with patients with isolated PR. 11 The relationship between various types and severity degrees of RVOT obstruction and ventricular function should be adequately addressed in further studies. Interestingly, in our study, higher LVM was associated with higher cRVEF.…”

“…11 Detailed analyses with the measurements of branch pulmonary artery cross-sectional area and that of the Nakata index were beyond the scope of the manuscript. Nevertheless, we and other investigators have previously demonstrated that patients after TOF repair with coexisting RVOT obstruction (including branch pulmonary stenosis) had lower RVEDV compared with patients without obstruction.…”