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

Figure 1

Example of a 4 x 4 high-intensity interval training session performed by a heart transplant recipient.

Figure 2

Intravascular ultra sound increases the sensitivity for early diagnosis of cardiac allograft vasculopathy compared to traditional angiography. Diffuse intimal thickening (area between the arrows) can be accurately identified by intra vascular ultra sound in contrast to angiography where only the lumen size is visible.