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Updated: Jun 21, 2026
Pre-clinical Model of Cardiac Donation after Circulatory Death
Published on: August 2, 2019
Modeling distribution of donor hearts to maximize early candidate survival
L W Stevenson1, S L Warner, M A Hamilton
1Ahmanson-UCLA Cardiomyopathy Center.
Insights
Prioritizing critical heart transplant candidates maximizes survival, increasing 1-year survival to 78%. This strategy remains beneficial even with increased operative mortality for critical patients. Identifying high-risk patients is key.
Area of Science:
- Cardiology
- Transplantation Medicine
- Health Services Research
Background:
- Cardiac transplantation priority should balance waiting list and operative mortality for outpatient and critical candidates.
- Optimizing donor heart allocation is crucial for maximizing patient survival.
- Current statistics inform models for predicting outcomes in different candidate groups.
Purpose of the Study:
- To determine the optimal distribution strategy for donor hearts to maximize overall survival in cardiac transplant candidates.
- To evaluate the impact of prioritizing critical candidates versus outpatient candidates on survival rates.
- To identify key factors influencing priority policy in heart transplantation.
Main Methods:
- A Markov model with eight states was developed using current statistics on patient outcomes.
- The model incorporated data on sudden death, deterioration to critical status, and operative mortality for both outpatient and critical candidates.
- Expected survival at one year was calculated under varying scenarios of donor heart allocation.
Main Results:
- Prioritizing critical candidates for donor hearts maximized overall candidate survival, increasing 1-year survival to 78% compared to 66% for outpatients.
- The survival benefit of prioritizing critical patients persisted even when their mortality rates were individually halved or doubled.
- A simultaneous doubling of outpatient sudden death and critical operative mortality showed a slight negative impact on survival with critical candidate priority.
Conclusions:
- Critical candidates should maintain priority for cardiac transplantation, even with potential increases in operative mortality.
- Postoperative outcomes must be evaluated alongside evolving pretransplantation risks.
- Donor heart allocation is most effective when focused on identifying waiting patients at the highest risk of sudden death or deterioration.
Background:
Priority for cardiac transplantation should reflect the relative waiting list mortality and operative mortality of outpatient candidates and critical candidates.
Methods And Results:
To determine how to distribute donor hearts for maximal overall survival, a Markov model of eight states was constructed from current statistics for outpatient sudden death, deterioration to critical status, operative mortality for outpatients, and operative mortality for critical candidates. Because the fraction of hearts offered to critical candidates varied, expected survival at 1 year was calculated. To determine the factors most critical in determining priority policy, current conditions were then varied over a fourfold range. Priority for critical candidates maximized overall candidate survival (with and without transplantation), increasing 1-year survival to 78% compared with 66% if hearts were offered only to outpatients. The benefit of giving priority to critical patients persisted when current group mortality rates were individually halved or doubled because these rates were still small compared with the 100% expected mortality of critical patients without transplantation. If the outpatient sudden death rate and the operative mortality for critical patients were doubled simultaneously, however, there was a slight negative impact on survival if critical candidates received priority. Regardless of changes in subgroup outcomes, the distribution of donor hearts had a relatively modest impact on survival because of the large excess of candidates.
Conclusions:
Critical candidates for transplantation should continue to receive priority even if their operative mortality increases above current levels. However, postoperative outcomes must be assessed in relation to changing pretransplantation risks. Distribution of donor hearts will be most beneficial when it is possible to identify the waiting patients at greatest risk for sudden death and deterioration without transplantation.
