Risk factors for early right ventricular-to-pulmonary artery conduit failure in congenital heart disease

Right ventricle-to-pulmonary artery conduits are a mainstay of treatment for patients with congenital heart defects. We investigated the association of underlying genetic abnormalities with conduit failure and hypothesized that 22q11.2 deletion syndrome was associated with shorter time to failure.

We conducted a single-center retrospective cohort study at the Children's Hospital of Philadelphia. Patients who underwent right ventricle-to-pulmonary artery conduit placement as part of a biventricular repair at 0 to 24 months of age between January 2010 and June 2020 were included. The primary exposure of interest was diagnosis of 22q11.2 deletion syndrome, and the outcome was time to conduit failure. The statistical analysis used cumulative incidence function with the Gray test and cause-specific Cox regression to account for competing risk.

In total, 143 patients met inclusion criteria, of whom 65 experienced conduit failure in the study period. The median time to failure was 89 months (7.4 years). Use of pulmonary homograft was independently associated with lower risk of conduit failure (hazard ratio, 0.29; confidence interval, 0.11-0.77, P = .01) and small conduit size was associated with greater risk of conduit failure (hazard ratio, 3.99, confidence interval, 1.69-9.41, P = .002) during the first 24 months. Presence of 22q11.2 deletion syndrome, age at initial surgery, and diagnosis of truncus arteriosus were not associated with conduit failure.

Although 22q11.2 deletion syndrome and other genetic syndromes were not associated with conduit failure, conduit size and type were the most important factors associated with conduit longevity and should be taken into account when planning surgical repair.