Exercise capacity in pediatric heart transplant recipient

Abstract

Most pediatric heart transplantation (HTx) recipients will reach adulthood. Exercise capacity measurement is essential during follow-up; however, there are few data available in the literature. Our study presents a monocentric, descriptive analysis of exercise capacity after pediatric HTx. Results of cardiopulmonary exercise testing (CPET) using cycle ergometry, performed between January and October 2021 as routine follow-up, were collected for exercise capacity analyses. VO2peak ≤ 80% predicted defined abnormal exercise capacity. Logistic regression and Pearson correlation were used to determine associated factors. Fifteen patients were included, and the age at CPET was 13.2 ± 3.2 years. One third of patients with maximal testing had low exercise capacity. The peripheral musculoskeletal function was the major limiting exercise factor. Resting HR was high for age at 108 ± 14.19 bpm. The mean percent predicted VO2peak (ppVO2peak) was 80.2 ± 20.8%. A linear correlation between age at transplant and ppVO2peak ( r = −0.53, P -value = 0.021) was found independent of time since transplant. Concurrent chronic diseases were a risk factor for abnormal VO2peak (odds-ratio = 17.5). Heart transplant recipients (HTR) in our study appeared to have better outcomes than that previously reported. The exercise capacity of pediatric HTR is above the lower limit. Patients younger at transplant have higher post-HTx exercise capacity, possibly due to the growth plasticity promoting nerve regeneration. Improved patient management or cardiac reinnervation may contribute to the better CPET results found in our study. Longitudinal or comparative studies with a larger sample size are required in the future.