Durability of large diameter right ventricular outflow tract conduits in adults with congenital heart disease

Subpulmonary ventricular outflow conduits are utilized routinely to repair complex congenital cardiac abnormalities, but are limited by the inevitable degeneration and need for reintervention. Data on conduit durability and propensity to dysfunction in the adult population are limited.

The study included 288 consecutive patients ≥18 years of age who were evaluated between 1991 and 2010 after placement of a ≥18 mm conduit. Freedom from hemodynamic conduit dysfunction served as our primary outcome. Freedom from reintervention, overall mortality and heart transplantation were also evaluated.

Median age at conduit implant was 19 years and median follow-up duration was 13 years. Probabilities of survival without conduit dysfunction and reintervention at 5, 10 and 15 years were 87%, 63%, and 49%, and 95%, 81%, and 56%, respectively. Smaller conduit diameter (18-20mm) was associated with lower probability of survival without dysfunction in the entire study cohort, with prominent effects in patients in both the lowest and the highest age quartiles. Other parameters with similar associations were higher BMI, native anatomy of tetralogy of Fallot or truncus arteriosus, and active smoking.

Adult congenital heart disease patients with conduit diameter ≥18 mm had an approximately 50% chance of developing hemodynamic conduit dysfunction and undergoing conduit reintervention by 15 years of post-implant, and a 30% likelihood of undergoing conduit reoperation in the same time frame. The importance of these data is underscored by the increasing number of adults with congenital heart diseases seeking care and the recent advances in transcatheter valve replacement for dysfunctional conduits.