Trends in Exercise Capacity Following Heart Transplantation

Abstract

Purpose While exercise capacity has been shown to improve following heart transplantation , transplant patients still have subnormal exercise capacities. We aimed to determine the natural history of exercise capacity post-transplant and whether resting heart rate impacts exercise capacity Methods Retrospective chart review was performed and patients who underwent multiple cardiopulmonary exercise testing (CPET) post-heart transplantation were identified. Fisher's exact test was used to compare categorical data with CPET variables and the Mann-Whitney test was used to compare continuous measures. Measurements over each year were considered repeated measures and fit with a linear mixed effect model. Results A total of 93 patients underwent CPET at 1-year post-transplant, 44 at 2 years, 32 at 3 years, and 17 at 4 years. The average age was 56.1(± 12.6) years, 87 (93.6%) patients were Caucasian, and 64 (68.2%) patients were male sex. There were no significant changes in CPET variables over the first four years following heart transplantation (Table 1). Resting heart rate at 1 year (≤ 95 vs >95) did not significantly impact exercise capacity after heart transplant . Patients with lower peak VO2 ( 70% predicted) remained stable over time. Conclusion While exercise capacity improves following heart transplantation, continued improvement was not observed in our transplant population. Resting heart rate following heart transplantation does not impact exercise capacity.