Neurocognitive outcomes after heart transplantation in early childhood

Abstract

Background: Children requiring heart transplantation (HTx) for congenital heart disease (CHD) or failing anatomically normal hearts (CMP) face different challenges pre-HTx. We compared the neurocognitive capabilities in pre-school-age children receiving HTx for CHD vs CMP and determined factors predicting outcomes.

Methods: Data were collected within a prospective multi-provincial project from children who underwent HTx ≤4 years of age between 1999 and 2011. At age 54 ± 3 months, we obtained scores from the Wechsler Preschool and Primary Scales of Intelligence for full-scale intelligence quotient (FSIQ) verbal intelligence quotient (VIQ) and performance intelligence quotient (PIQ), and from the Beery-Buktenica Developmental Test for visual-motor integration (VMI). Possible predictive factors were collected prospectively from transplant listing.

Results: Of the 76 patients included in the study, 61 survived to assessment, 2 were lost to follow-up and 4 were excluded for genetic disorders or heart-lung transplant. The CHD patients (n = 32) had significantly more previous surgeries, more severe kidney injuries, more days on ventilator and in intensive care, broader human leukocyte antigen (HLA) sensitization, longer cardipulmonary bypass (CPB) times and higher inotropic scores than CMP patients (n = 23). Mean IQ scores for the HTx children were below population norms and significantly lower in children with CHD. Intellectual disability (FSIQ <70) was more common in the CHD group (p = 0.036). The lower VMI in CHD patients approached significance. Lower FSIQ and VMI were independently associated with higher pre-HTx creatinine and lactate, longer stay in intensive care and lower socioeconomic status.

Conclusions: Children post-HTx showed IQ and VMI scores within the borderline to low-average range, with CHD children ranging significantly lower. Low scores are associated with a more difficult pre- and peri-transplant course. Careful follow-up is required to warrant early detection of deficits and introduction of interventions and supportive measures.

Keywords: IQ testing; cardiomyopathy; congenital heart disease; neurocognitive outcomes; neurodevelopment; pediatric heart transplantation.