**2. Epidemiology of cardiac re-transplantation**

The number of patients undergoing ReTx has been gradually increasing over time. Between 2000 and 2005, ReTx accounted for 2.9% of all heart transplants [3]. Between January 2009 and June 2015 there were 722 patients who underwent ReTx, which constituted 3.1% of heart transplants. While this seems like a small increase over time, there has been a simultaneous shift towards more rigorous patient selection for ReTx. This shift has been a response to the uniformly poor outcomes when patients undergo ReTx for acute events like primary graft failure. In this context, the median survival of patients undergoing cardiac transplantation has increased from 8.5 years in the era of 1982–1991 to almost 12 years for patients transplanted between 2002 and 2008. Median survival is even longer in young patients, with a median survival of 12.6 years in patients undergoing initial transplant between age 18 and 39, compared to 9.1 years in patients aged 60–69. Patients under age 40 comprise 17% of the adult heart transplant population, but also represent the population most likely to require to eventually require ReTx. There is no reason to believe that there will not be an ongoing trend towards improved survival, potentially increasing the number of patients considered for ReTx.

Most of the data regarding the epidemiology of ReTx is only reflective of patients who successfully undergo ReTx. Therefore, in order to demonstrate the potential increase in candidates for ReTx, we have provided an estimate based on outcomes in current transplant recipients, shown in **Figure 1**. Currently 74% of patients are surviving at least 5 years after their initial transplant date [5]. We will assume that patients who die before this time are not candidates for ReTx given poor outcomes in patients undergoing ReTx for acute graft failure. The proportion of patients who are over age 60 at the time of initial cardiac transplant is 23.8% [5]. For the sake of a conservative estimate, we will assume that these patients are not candidates for ReTx due to advanced age. In patients who die more than 5 years after transplant, CAV accounts for 7–17% of deaths and graft dysfunction accounts for 22–40% of deaths [5]. If all patients under age 60 at initial transplant who eventually die from CAV or graft dysfunction are assessed for ReTx, then 17% of all transplant patients could potentially be ReTx eligible. There are several assumptions built into this estimate. Many patients who are potential ReTx candidates due to CAV will not be eligible due to sudden death [8], or co-morbidities that preclude ReTx. However, if even half of the patients we estimated undergo ReTx this would essentially triple the current rate of ReTx.

**3. Characteristics of cardiac re-transplant recipients**

registry data [5, 9].

Patients who undergo ReTx have characteristics distinct from those undergoing initial transplant. Some of these characteristics are related to procedures and immunosuppression required for the initial cardiac transplant. Meanwhile, other characteristics are related to surviving long enough to be considered for ReTx. However, as noted previously, this data only

**Figure 1.** Estimate of the number of patients who may be candidates for cardiac ReTx. Estimates are based on ISHLT

Cardiac Re-Transplantation: A Growing Indication with Unique Considerations

http://dx.doi.org/10.5772/intechopen.74585

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**Figure 1.** Estimate of the number of patients who may be candidates for cardiac ReTx. Estimates are based on ISHLT registry data [5, 9].
