Donor heart acceptance rate drops as demand rises

Despite growing waiting lists and national efforts to increase the use of available donor organs, the rate of hearts accepted for transplantation has decreased significantly since 1995, a study found.

The study, published online Feb. 10 in the American Journal of Transplantation, analyzed Organ Procurement and Transplantation Network (OPTN) data for all potential adult cardiac organ donors between 1995 and 2010. In that period, acceptance rates dropped from 44 percent to 29 percent in 2006 before increasing to 32 percent in 2010.

The study found hearts more likely to be rejected were from female donors—who made up 41 percent of donors—donors over age 50 and donors who had medical comorbidities. Those predictors of nonacceptance were consistent throughout all United Network for Organ Sharing (UNOS) regions, although some regions had higher acceptance rates than others. During the study period, there was an increase in donor age and in prevalence of comorbidities, including hypertension and diabetes, among donors. 

Part of the cause of the shrinking acceptance rate is the lack of standard guidelines for donor heart evaluation and acceptance, which likely resulted in nonrecovery of potentially useful organs, wrote lead author Kiran K. Khush, MD, of Stanford University School of Medicine in California, and colleagues. Also, the use of mechanical circulating support devices to stabilize patients may be contributing to lower acceptance rates. 

“The option of stabilizing a patient with mechanical support as a bridge to transplant may make donor hearts with one or more undesirable features less likely to be accepted for transplantation,” they wrote. “Moreover, once an LVAD (left ventricular assist device) is implanted, centers may be reluctant to transplant a ‘marginal’ donor heart into a stable device recipient.”

Increased scrutiny of post-transplant outcomes by regulating bodies also may contribute to the decrease in accepted hearts. Negative outcomes and metrics could cause transplant centers to be warned, reprimanded, placed on probation or closed and could result in the loss of Medicare certification. Any warning, reprimand or penalty might affect a center’s contracts with managed-care companies and loss of designation as a center of excellence.

“Thus, federal oversight may have had the unintended consequence of increased risk aversion in donor heart acceptance decisions, thereby reducing heart transplant rates,” the authors wrote. And the “more conservative” acceptance practice hasn’t led to much improvement in survival rates: There was just a 3 percent increase in 30-day and one-year recipient survival over the study period, and that might be due as much or more to improvements in postoperative care or immunosuppression.

About half of patients diagnosed with heart failure will die within five years, the authors wrote. “This sobering fact, combined with the rising incidence of heart failure in the United States, underscores the urgent need for donor hearts for transplantation. The severe and persistent shortage of donor organs, however, considerably limits the availability of heart transplantation, and highlights the importance of using all available organs, when deemed safe and feasible.”