Page 11 - Heart Transplant Guidelines
P. 11

Heart Function Service: Heart Transplant Guidelines

               Donor Offers

               The national rate of rejection of donor hearts is 44%. The current literature on possible donor criteria,
               risk factors and their associations with outcomes (age, gender, size mismatch, mode of death,
               downtime, cardiac function, inotropes, ischemic time, travel distance, infections, HR social behavior and
               HLA compatibility), as well as impact of multiple risk factors (calculators) is not robust. The data has
               severe limitations; specifically a lack of prospective studies, heavy reliance on registry data, small
               retrospective single center studies and outcomes assessing survival from transplant rather than survival
               from listing. The only convincing evidence of risk factors causing worse transplant outcomes is extremes
               of ischemic time (less than 1 hour or more than 6 hours) with a relative risk ratio of 1.7 and use of
               donors more than 25 years older than the recipient (relative risk 1.5). Putting these into context,
               recipient risk factors and center volume have hazard ratios between 1.9 and 4.5. The data showed no
               evidence of worse outcomes when “marginal donors” were used.

               The psychology and behavioral science of using marginal donors in status 1A patients and not in Status 2
               patients was explored. An adult cardiac study reported that status 2 recipients had equal outcomes with
               any donor quality.

               The meeting unanimously agreed that our practice should change to reflect this information. The team
               will avoid taking donors older than 40 yrs or who have significant cardiac trauma or large size
               mismatches (D:R ratio of <0.8 or >3) unless exceptional circumstances existed. Any other concerns
               regarding the donor quality (structural heart disease, HLA compatibility, malignancy, infection, ischemic
               time, distance, questionable cause of death, deconditioned donor, inotrope use, function,
               CPR/downtime) would be a reason for discussion with the relevant physicians. For example HLA
               incompatibility would be discussed with transplant immunology, an infected patient would be discussed
               with ID team etc. Patient status would no longer be a significant consideration in evaluating donors with
               concerns regarding quality.

               ABO-Incompatible Heart Transplantation

               ABO-Incompatible heart transplantation (ABOi) was first undertaken in young infants by Lori West’s
               group in Toronto in 1997   to maximize the chance of an infant being transplanted and minimize refusal
               of otherwise suitable donor organs.  Table 1 demonstrates the various combinations of transplant
               compatibility. Multicenter collaborations have demonstrated long term outcomes indistinguishable from
               ABO compatible transplants  .  Since then the indications have extended outside the infant age range
               and to sensitized patients   although OPTN restrictions some of these practices.

               Table 1
                    Recipient                      Compatible donor                Incompatible
                    O                              O                               A, B, AB
                    A                              O, A                            AB, B
                    B                              O, B                            A, AB
                    AB                             O, A, B, AB                     ---

               Updated December 14, 2018                                                                   11
   6   7   8   9   10   11   12   13   14   15   16