Cardiac transplantation is the treatment of choice for many patients with end-stage heart failure (HF) who remain symptomatic despite optimal medical therapy. Risk stratification of patients with end stage HF is pivotal for transplant candidate selection. The primary indications for cardiac transplantation along with the specific inclusion and exclusion criteria are discussed here.
Prognosis after cardiac transplantation and treatment of refractory HF are discussed separately. (See "Prognosis after cardiac transplantation" and "Management of refractory heart failure".)
WAITING LIST AND ALLOCATION
The Registry of the International Society for Heart and Lung Transplantation reported 4196 heart transplants worldwide in 2012 (www.ishlt.org/registries) . This is probably an underestimate, as reporting to the registry is voluntary outside of the United States. In the United States, where reporting to the United Network Of Organ Sharing (UNOS) has been mandatory for the past two decades, the number of United States heart transplants performed has been stable at approximately 2300 cases annually (figure 1). The majority of centers perform between 10 and 19 heart transplants per year.
The number of transplant centers has decreased from 243 in 1996 to 204 in 2007. The ongoing organ donor shortage has been the major limitation to the growth of this therapy. Due to this critical organ shortage, the recipient selection process and donor allocation system have involved both clinical and ethical issues.
Donor allocation — In an effort to ensure equitable distribution of donor hearts, UNOS (a private organization under contract to the federal government) has created and regularly updates an organ allocation system (Organ Procurement and Transplantation Network, OPTN) . This system delineates prioritization rules that take into account the clinical severity of illness, time accrued on the wait list, blood type compatibility, and geographic distance. With heart procurement, the duration of ischemic time for the donor heart is a limiting factor in organ retrieval, with ischemic times greater than four hours associated with a higher rate of primary graft failure. Accordingly, geographic distance between the donor hospital and the transplant center is measured in 500 nautical mile circular concentric zones.