Preventing Valve Failure in Transcatheter Pulmonary Valve Replacement by Optimizing Implant Size to Body Surface Area

Background
Optimal valve sizing at time of implantation during Transcatheter Pulmonary Valve Replacement (TPVR) is unknown. Prior studies have correlated body surface area (BSA) to pulmonary valve annulus diameter for surgical valve implantation however, data is lacking for TPVR.

Methods
We performed a retrospective review of all TPVR at our institution from 2011-2017. We evaluated implant characteristics and then for valve failure – defined as a post-implant echo PG>35mmHg, repeat transcatheter intervention, surgical valve explantation (non-endocarditis) or death. Our primary aim was to assess for optimal valve size to BSA in the pediatric population.

Results
Pediatric (n=69) and adult congenital (n=81) patients were analyzed. The cohorts (pediatric vs adults) varied; median age 12 vs 30 years, weight 46.9 vs 70.9 kg, and BSA 1.44 vs 1.82 m². The pre-intervention RVOT gradient was 35 vs 25 mmHg, with the post-valve gradient of 11 vs 7 mmHg, and a final stent diameter (FSD) of 19.4 vs 20.4 mm. There were 46 valve failures within 150 TPVR – 11 adult (14%) and 35 pediatric (51%). Within the pediatric cohort, the male FSD:BSA at valve implant was lower in the valve failure (n=24) vs non-failure (n=20) at 12.2 vs 14.7 mm/m2 (p=<0.01). Similarly, FSD:BSA was lower in female valve failures (n=11) vs non-failures (n=10) at 13.3 vs 14.4 mm/m2 (p=0.02). Utilizing a FSD:BSA cutoff of greater than or equal to 12 mm/m2 at the time of TPVR lead to greater freedom from valve failure and reintervention (Figure).

Conclusions
When planning TPVR in the pediatric population, operators should carefully consider the ability to implant at optimal sizing for BSA in order to maintain valve longevity