Transcatheter pulmonary valve implantation in patients with repaired tetralogy of Fallot: International evidence and the current status in Japan.

In repaired tetralogy of Fallot (TOF), chronic pulmonary regurgitation drives right ventricular (RV) dilation, ventricular arrhythmias, and heart failure. Surgical pulmonary valve replacement improves outcomes but requires redo sternotomy. Transcatheter pulmonary valve implantation (TPVI) has emerged as a less invasive alternative. This review summarizes contemporary evidence and the Japanese context for TPVI. International registries report high procedural success and favorable mid-term outcomes with both balloon-expandable and self-expanding platforms. In Japan, two platforms are approved-SAPIEN 3 transcatheter heart valve (THV) (Edwards Lifesciences, Irvine, CA, USA) and Harmony transcatheter pulmonary valve (TPV) (Medtronic Inc., Minneapolis, MN, USA)-reflecting distinct anatomic targets. SAPIEN 3 THV is indicated for degenerated conduits or surgical bioprostheses in high-risk candidates, whereas Harmony TPV targets native, often dilated RV outflow tracts mainly after transannular patch repair. Although indications remain relatively restricted in Japan, early outcomes are expected to be favorable as experience grows. Key unresolved issues include long-term valve durability, post-TPVI antithrombotic strategy, arrhythmia surveillance, coronary compression risk, and timely referral before irreversible RV remodeling. Overall, TPVI has transformed the management of pulmonary valve dysfunction after TOF repair and is increasingly recognized as first-line therapy in appropriate anatomies. In Japan, accumulating TPVI experience-combined with optimized patient selection and refinements in treatment strategy-is expected to further improve procedural safety and clinical outcomes. National registries and high-quality domestic studies are needed to guide indications, optimize lifetime strategies, and extend the benefits of TPVI.