Rapid Progression of Right Ventricular Deterioration and Timing of Pulmonary Valve Replacement in Repaired Tetralogy of Fallot.

BACKGROUND

We aimed to identify a progressive phenotype in repaired tetralogy of Fallot (rTOF), characterised by accelerated changes in right ventricular (RV) parameters on cardiac magnetic resonance (CMR) and assess its association with an accelerated course to pulmonary valve replacement (PVR).

METHOD: This was a retrospective study of patients with rTOF who had two or more CMRs (2005-2022). Clinical variables and CMR data were collected, and annualised changes in CMR data were calculated. "Rapid progressors" were classified as those with annual RV ejection fraction decreases>3.5% or RV end-diastolic volume index (RVEDVi) increases>3.5 mL/m2.

RESULTS

A total of 112 patients with rTOF (median age 14.7 years, 63 males) were included, with 60 identified as rapid progressors (12 based on RV ejection fraction, 48 based on the RVEDVi criteria). Baseline RV volumes and function were similar between groups, although rapid progressors had a higher pulmonary regurgitant fraction (PRF) (38.2±16.3 vs 31.4±15.4%; p=0.033). Pulmonary regurgitant fraction (PRF) (odds ratio 1.03; 95% confidence interval [CI] 1.00-1.05; p=0.037) and RV end-diastolic volume/left ventricular end-diastolic volume ratio (odds ratio 2.75; 95% CI 1.13-7.35; p=0.032) were significant predictors of the rapid progressive phenotype. During follow-up (median 9.3 years, interquartile range 6.8-13.8), 48 patients underwent PVR. Rapid progressors had a five-fold increased risk of PVR (hazard ratio 5.44; 95% CI 2.75-10.8; p<0.001). Adjusting for age, sex, transannular patch use, baseline RVEDVi, and PRF, the risk of PVR remained over five-fold higher in rapid progressors (hazard ratio 5.18; 95% CI 4.39-5.97; p<0.001).

CONCLUSIONS

This study identifies imaging biomarkers in the rTOF subpopulation that were more likely to have an early PVR.