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Finding more transplant hearts but not more donors

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New donor model shows promise

How the University of Washington researchers brought about such a dramatic increase in donor heart utilization raises a number of questions, Dr. Nicholas Smedira of Cleveland Clinic said in his invited commentary (J Thorac Cardiovasc Surg 2016;151:243-4).

“They refer euphemistically to ‘behavioral adaptation’ and ‘frank discussions’ regarding ‘individual and group bias’ as explanations, but understanding exactly how this is accomplished is not easy,” Dr. Smedira said.

Noteworthy is that the researchers used more donors who meet Center for Disease Control and Prevention high risk criteria for infectious disease. However, cardiologists tend to weigh their decision for accepting donor hearts “by the last memorable or distressful experience,” Dr. Smedira said. Hence, many of these donor hearts go unused. At the same time, assessing risk without complete information is challenging, he said.

Besides their thought processes, other factors that influence cardiologists’ decisions on accepting donor hearts include fatigue, scheduling conflicts, reimbursement issues, and outcome metrics. He credited the University of Washington for its “courage” to examine their decision-making process, including exploring biases as well as working “collectively and blamelessly” to support their decisions. “I would encourage more transplant centers to follow a program similar to the University of Washington’s and maybe we will be hearing more yeses and fewer nos,” Dr. Smedira said.

He had no relationships to disclose.


 

References

Heart transplant volumes in the United States have remained static since the start of the century because of improved trauma prevention and treatment, but that has challenged cardiologists to find enough donor hearts for the growing ranks of advanced heart failure patients. So a multidisciplinary team at the University of Washington in Seattle initiated a quality improvement program that doubled transplant volume without any change in transplant-related deaths by accepting hearts they would have otherwise discarded.

The study came about after the researchers determined that a large number of donor hearts from their own organ procurement program were being sent to other transplant centers. So they gathered a multidisciplinary team of transplant surgeons, cardiologists, and members of the organ procurement program to study ways to improve its center-specific organ utilization rate. The endeavor resulted in an increase in utilization rates from 28% to 49% in a year, a rate that has been sustained through a second year, according to study findings published in the January issue of the Journal of Thoracic and Cardiovascular Surgery (2016;151:238-43).

“The simple process of systematically reviewing donor turn down events as a group tended to reduce variability [and] increase confidence in expanded criteria donors and resulted in improved donor organ utilization and transplant volumes,” lead author Dr. Jason Smith and colleagues said.

The 30-day and 1-year death rates were similar before and after the quality improvement program started, but the death rates of those on the heart wait list declined from 17.2% to 12%, “which was not statistically significant,” Dr. Smith and coauthors said, “but does show that increasing use of organs that may be outside of the usual pattern has a trend toward improved wait list survival and needs to be considered when assessing donor hearts.”

Because of excellent results of heart transplants in patients with advanced heart failure, a number of investigators have proposed expanding the population of heart donors to include older people, those with higher risk of infectious disease, or with heart disease such as coronary artery disease and left ventricular hypertrophy, Dr. Smith and coauthors said. Their own review found a higher-than-expected rate of donor hearts sent to other centers from the University of Washington organ procurement program.

The multidisciplinary team analyzed the organs the University of Washington surgeons refused and sent to other institutions from July 2012 to June 2013.

For a year after that, the multidisciplinary group did real-time analysis of organ refusal along with quarterly reviews “in a non-confrontational, proactive” setting, as Dr. Smith and his colleagues described it. The group held open discussions on refused organs that were ultimately transplanted elsewhere. “The review process was facilitated to provide a constructive environment to encourage development of best practices and consistency,” the researchers noted. The quality improvement program led to an increase in the unit’s transplant volume despite fewer donor offers.

The researchers acknowledged that donor assessment has been the focus of much controversy. They pointed out that average donor age has increased over the last 20 years from 29 years to 33 years and has since retreated to 31 years, and some programs utilize donors up to their mid-60s. Also, previous studies have advocated for the use of donors who meet the criteria of the Centers for Disease Control and Prevention high risk behavior of infection as well as some drug abusers because of the low-risk of transmission and emerging evidence affirming the safety of hearts of drug users.

“The individual decision to utilize or discard a donor organ is one of the most challenging aspects of transplant medicine,” Dr. Smith and colleagues said. “It requires balancing donor risks against the exigencies of the recipient.”

Today, the multidisciplinary team evaluates each heart offered for donation and is exploring ways to accept even more donor hearts, even discarded hearts. “This represents a large, untapped pool of potential donor hearts that might add to the net number of transplants performed nationally and not merely redistribute organ usage,” Dr. Smith and colleagues said.

Dr. Smith is a consultant for Thoratec and is a primary site investigator for the EXPAND Trial sponsored by TransMedics. Dr. Todd Dardas is supported by the American College of Cardiology/Daiichi Sankyo Career Development Award. Dr. Jay Pal receives grant support from Tenax. Dr. Wayne Levy is a consultant for HeartWare, Novartis, GE Healthcare, Pharmin, and Biotronik. Dr. Claudius Mahr is a consultant for Thoratec, HeartWare and Abiomed. Dr. Nahush Mokadam is a consultant for Thoratec, HeartWare, Syncardia and St. Jude Medical, and has research grants from Thoratec, HeartWare and Syncardia. The other coauthors had no relationships to disclose.

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