Exercise after heart transplantation: An overview

Abstract

While life expectancy is greatly improved after a heart transplant, survival is still limited, and compared to the general population, the exercise capacity and health-related quality of life of heart transplant recipients are reduced. Increased exercise capacity is associated with a better prognosis. However, although several studies have documented positive effects of exercise after heart transplantation (HTx), little is known about the type, frequency and intensity of exercise that provides the greatest health benefits. Moreover, the long-term effects of exercise on co-morbidities and survival are also unclear. Exercise restrictions apply to patients with a denervated heart, and for decades, it was believed that the transplanted heart remained denervated. This has since been largely disproved, but despite the new knowledge, the exercise restrictions have largely remained, and up-to-date guidelines on exercise prescription after HTx do not exist. High-intensity, interval based aerobic exercise has repeatedly been documented to have superior positive effects and health benefits compared to moderate exercise. This applies to both healthy subjects as well as in several patient groups, such as patients with metabolic syndrome, coronary artery disease or heart failure. However, whether the effects of this type of exercise are also applicable to heart transplant populations has not yet been fully established. The purpose of this article is to give an overview of the current knowledge about the exercise capacity and effect of exercise among heart transplant recipients and to discuss future exercise strategies.

Keywords: Heart transplant, Exercise, Exercise capacity, Muscle strength, Maximum oxygen uptake, Denervation, Reinnervation, Cardiac allograft vasculopathy, Quality of life

Core tip: It is time to rethink exercise strategies among heart transplant populations. Chronotropic incompetence is not necessarily a factor that limits exercise capacity in heart transplant recipients, and the exercise restrictions that have traditionally been applied to patients with a denervated heart can be disregarded. High-intensity, interval-based aerobic exercise is superior to moderate exercise in patients with coronary artery disease and heart failure, and the positive effects of this type of exercise seem to also be largely reproducible among heart transplant recipients.