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Updated: May 22, 2026
A High-Fidelity Porcine Model of Orthotopic Heart Transplantation Following Donation after Circulatory Death
Published on: June 6, 2025
Should orthotopic heart transplantation using marginal donors be limited to higher volume centers?
Arman Kilic1, Eric S Weiss, Jeremiah G Allen
1Division of Cardiac Surgery, Department of Surgery, Johns Hopkins Hospital, Baltimore, Maryland 21287, USA.
Insights
Orthotopic heart transplantation (OHT) outcomes are worse at low-volume centers when using marginal donors. Consolidating marginal donor use at high-volume centers may improve survival and reduce complications for transplant recipients.
Area of Science:
- Cardiology
- Transplantation Surgery
- Health Services Research
Background:
- Orthotopic heart transplantation (OHT) outcomes are influenced by various factors, including donor organ quality and transplant center experience.
- Marginal donors, defined by a high donor risk score (≥7), represent a higher-risk organ pool for OHT.
- Institutional volume is a potential determinant of post-transplant outcomes, particularly when utilizing challenging donor organs.
Purpose of the Study:
- To investigate the association between institutional orthotopic heart transplantation (OHT) volume and patient outcomes.
- To determine if transplanting marginal donors at higher-volume centers improves survival rates and reduces post-transplant complications.
- To analyze the impact of center volume on mortality, graft survival, and adverse events in OHT recipients using marginal donors.
Main Methods:
- Retrospective analysis of adult patients undergoing OHT with marginal donors (donor risk score ≥7) from 2000-2010 using the UNOS database.
- Stratification of transplant centers into equal tertiles based on annual OHT volume (low, intermediate, high).
- Comparison of 30-day, 1-year, and 5-year posttransplant mortality, graft survival, and complication rates (rejection, malignancy, infection) across center volume groups using Cox regression and Kaplan-Meier analyses, adjusting for recipient and donor risk factors.
Main Results:
- Low-volume centers were associated with significantly increased risks of 30-day, 1-year, and 5-year mortality following OHT with marginal donors.
- Kaplan-Meier analysis revealed a trend of decreased 1-year survival with decreasing center volume (High: 86.0%, Intermediate: 85.7%, Low: 81.2%).
- Higher incidences of drug-treated rejection, death from malignancy, and death from infection were observed at low-volume centers compared to high-volume centers.
Conclusions:
- Lower institutional volume is linked to poorer outcomes in orthotopic heart transplantation (OHT) when utilizing marginal donors.
- Consolidating the use of marginal donors at higher-volume transplant centers may be a strategy to enhance post-transplant survival and reduce adverse events.
- These findings suggest a volume-outcome relationship that warrants consideration for resource allocation and patient referral in OHT programs using higher-risk donor organs.
Background:
This study examined whether institutional volume impacts outcomes after orthotopic heart transplantation (OHT) utilizing marginal donors.
Methods:
Adult patients undergoing OHT with the use of marginal donors between 2000 and 2010 were identified in the United Network for Organ Sharing database. A previously derived and validated donor risk score (range, 1 to 15) was used to define marginal donors as those in the 90th percentile of risk (score≥7). Patients were stratified into equal-size tertiles based on overall institutional OHT volume. Posttransplant outcomes were compared between these center cohorts.
Results:
A total of 3,176 OHTs utilizing marginal donors were identified. In Cox regression analysis, recipients undergoing OHT at low-volume centers were at significantly increased risk of 30-day (hazard ratio 1.82 [1.31 to 2.54], p<0.001), 1-year (hazard ratio 1.40 [1.14 to 1.73], p=0.002), and 5-year posttransplant mortality (hazard ratio 1.29 [1.10 to 1.52], p=0.02). These findings persisted after adjusting for recipient risk, differences in donor risk score, and year of transplantation (each p<0.05). In Kaplan-Meier analysis, there was a similar trend of decreasing 1-year survival with decreasing center volume: high (86.0%), intermediate (85.7%), and low (81.2%; log rank p=0.003). Drug-treated rejection within the first post-OHT year was more common in low-volume versus high-volume centers (34.3% versus 24.2%, p<0.001). At an overall mean follow-up of 3.4±2.9 years, low-volume centers also had higher incidences of death due to malignancy (2.8% versus 1.3%, p=0.01) or infection (6.2% versus 4.1%, p=0.02).
Conclusions:
Consolidating the use of marginal donors to higher volume centers may be prudent in improving post-OHT outcomes in this higher risk patient subset.
