Cardiac transplantation is the primary therapy for patients with end-stage heart failure, who remain symptomatic despite optimal medical therapy. For carefully selected patients, heart transplantation offers markedly improved survival and quality of life (Alraies and Eckman, 2014).

The most common indications for adult heart transplantation in the US for 2015 were cardiomyopathy (59.3%), coronary heart disease (35.0%) and congenital heart disease (3.2%) (Colvin et al., 2017).

Older patients, as well as younger patients with complex congenital heart disease, are increasingly being considered for transplantation. In addition, there have been small increases in the number of patients requiring mechanical circulatory support (MCS) prior to transplantation, and those who are evaluated for re-transplantation (Hunt and Haddad, 2008). Improvement in left ventricular assist devices has enabled their use as destination therapy for some patients with chronic heart failure, as well as a bridge to transplantation in others (Abraham and Smith, 2013).

While an increasing number of heart transplants are taking place each year (Koomalsingh and Kobashigawa, 2018), acute rejection of heart transplants remains a problem with first-year rejection rates of 23% observed in the US in 2015 (Colvin et al., 2017). It is important to recognise that although the available pool of heart donors should expand through better ex vivo preservation more still needs to be done to improve and optimise immunosuppression and patient outcomes (Koomalsingh and Kobashigawa, 2018).