Exercise capacity following pediatric heart transplantation: A systematic review

Abstract

Pediatric HTs account for 13% of all HTs with >60% of recipients surviving at least 10 years post-HT. The purpose of this systematic review is to synthesize the literature on exercise capacity of pediatric HT recipients to improve understanding of the mechanisms that may explain the decreased exercise capacity. Six databases were searched for studies that compared the exercise capacity of HT recipients ≤21 years old with a control group or normative data. Sixteen studies were included. Pediatric HT recipients, as compared to controls or normative data, exhibit significantly higher resting HR, and at peak exercise exhibit significantly decreased HR, VO₂ , power, work, minute ventilation, and exercise duration. Peak VO₂ appears to improve within the first 2.5 years post-HT; peak work remains constant; and there is inconclusive evidence that peak HR, HR recovery, and HR reserve improve with time since HT. These results are discussed in the context of the mechanisms that may explain the impaired exercise capacity of pediatric HT recipients, including chronotropic incompetence, graft dysfunction, side effects of immunosuppression therapy, and deconditioning. In addition, the limited literature on rehabilitation after pediatric HT is summarized.

Keywords: cardiac transplantation; exercise capacity; heart rate; heart transplantation; oxygen consumption; pediatric.