As demand for heart transplants continues to far exceed the number of available donor hearts, experts at today’s 46th Annual Meeting and Scientific Sessions of the International Society for Heart and Lung Transplantation (ISHLT) explored a critical question: how should this scarce, life-saving resource be allocated?
In his presentation, “Allocation Models Beyond the US: Scoring or Status? Global Perspectives,” Guillaume Coutance, MD, highlighted how different countries approach this complex challenge — and why no single system has emerged as the optimal solution.
Approximately 7,000 heart transplants are performed annually worldwide, while about 10-15 percent of patients on the waiting list for a heart die before transplantation. “A shortage in donor hearts is the primary limiting factor to performing more heart transplants,” said Dr. Coutance, Cardiologist, Department of Heart Transplantation at Georges Pompidou European Hospital, Paris. “Because donor hearts are limited, allocation systems must carefully balance competing priorities: saving the sickest patients, maximizing transplant success, and ensuring fairness.”
Two Major Allocation Schemes
In a review of 24 countries, Dr. Coutance identified 11 different allocation schemes; however, most fall into two main categories:
“Status-based systems may sometimes reflect the intensity of care rather than true medical urgency, and may be vulnerable to variable clinical practices,” he said. “However, the predictive modeling used in score-based systems remains imperfect with limited statistical performance of predictive models applied in such allocation schemes.”
Within the allocation approaches deployed globally, key differences include:
France’s Data-Driven Model
France replaced its urgency-based approach with its current score-based allocation system in 2018.
“At its core, the French model ranks all patients on the waiting list using a single composite score that allows for direct comparison between candidates across the country,” he said. “This approach aims to ensure that organs are allocated to those who need them most while also maximizing the chances of transplant success.”
The composite score is based on a four-step calculation process designed to balance equity, efficiency, and transparency:
“Unlike simpler status-based systems, which rely on broad clinical categories, our model aims for a more individualized and continuous prioritization of patients,” he said.
Dr. Coutance said although studies suggest score-based systems have helped standardize allocation decisions and reduce the unnecessary use of aggressive therapies aimed solely at increasing priority status, they have not significantly changed transplant outcomes.
“No allocation system has proven clearly superior in terms of improving both pre-and post-transplant outcomes,” he said. “All systems face the same fundamental challenge: how to balance urgency, utility, and equity in the context of organ shortage.”
Allocation systems must also continue to adapt as medicine advances and clinical practices change.
“The growing use of mechanical support devices, changing patient populations, and improved data analytics are all reshaping how allocation decisions are made,” Dr. Coutance said. “There is no perfect allocation system. Every model must balance urgency, fairness, and expected benefit — and all must contend with the reality of organ shortage.”
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ABOUT ISHLT
The International Society for Heart and Lung Transplantation (ISHLT) is a not-for-profit, multidisciplinary, professional organization dedicated to improving the care of patients with advanced heart or lung disease through transplantation, mechanical support, and innovative therapies via research, education, and advocacy. ISHLT members focus on transplantation and a range of interventions and therapies related to advanced heart and lung disease.