Mid-term ventricular function in patients with tetralogy of Fallot after transcatheter pulmonary valve replacement: Relationship to baseline right ventricular loading conditions.

Background: We investigated the mid-term systolic ventricular response to transcatheter pulmonary valve replacement (TPVR) in patients with repaired tetralogy of Fallot (TOF) and pulmonary stenosis (PS), pulmonary regurgitation (PR) and a MIXED subgroup that included patients with both PR and PS.

Methods: We included patients with repaired TOF with PS, atresia and absent pulmonary valve underwent TPVR (2007-2011) and followed at BCH until 2021. We compared their serial clinical, echo imaging as well as cardiopulmonary exercise test data among PS, PR and MIXED subgroups.

Results: In 63 patients (20.8 years of age) the median early follow-up (FU) after TPVR was 6.2 months, and mid-term - 2.8 years. At baseline, the PR (n = 23) had lower LV EF, mass z-scores and global longitudinal strain (GLS) and the percent predicted peak O2 pulse than PS (n = 16) and those in the MIXED (n = 24) subgroups. BiV GLS improvement from baseline to early and to midterm FU occurred for all subgroups except for the LV GLS in the MIXED, which showed improvement from baseline to early follow-up. PR subgroup's LV GLS had gradual improvement, it remained lower than in PS and MIXED. No significant difference in exercise parameters were seen following TPVR. Freedom from reintervention at 10 years of FU was only 13.4 %.

Conclusions: Patients with PR had lower LV systolic function and exercise capacity than those with PS or MIXED prior TPVR with normalization of systolic function midterm in all thereafter. Overall, about 1 in 8 remained free from reintervention after 10 years.