Marginal donors: can older donor hearts tolerate prolonged cold ischemic storage?
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Updated: May 8, 2026
Innovative Strategies for Organ Preservation in Heart Transplantation: Uniform Cooling Preservation and Ex-situ Normothermic Perfusion
Published on: November 28, 2025
Sevil Korkmaz1, Susanne Bährle-Szabó, Sivakkanan Loganathan
1Laboratory of Cardiac Surgery, Department of Cardiac Surgery, University of Heidelberg, INF 326 (2. OG), 69120, Heidelberg, Germany, korkmaz@uni-heidelberg.de.
Insights
Older donor hearts show reduced function and increased vulnerability after prolonged cold ischemia during early heart transplantation. Endothelial dysfunction worsens with longer preservation times, impacting graft outcomes.
Area of Science:
- Cardiology
- Transplantation Medicine
- Vascular Biology
Background:
- Advanced donor age and prolonged ischemic time are known risk factors for heart transplant mortality.
- Early graft dysfunction significantly impacts long-term transplant outcomes.
- The functional consequences of older donor hearts with varying ischemic times require further evaluation.
Purpose of the Study:
- To assess the in vivo cardiac and coronary vascular function of old-donor rat hearts after short (1 hour) and prolonged (8 hours) cold ischemic times.
- To compare the functional recovery of old-donor hearts with young-donor hearts post-transplantation.
Main Methods:
- Hearts were harvested from young (3-month-old) and old (18-month-old) donor rats.
- Donor hearts underwent heterotopic transplantation after cold storage for 1 or 8 hours.
- Left-ventricular (LV) function and coronary blood flow were evaluated post-transplantation.
Main Results:
- After 1 hour ischemia, old-donor hearts showed comparable LV function but reduced endothelium-dependent vasodilation.
- After 8 hours ischemia, old-donor hearts exhibited significantly reduced LV pressure, contractility (dP/dt max), coronary blood flow, and vasodilation response.
- Two old-donor hearts failed to show mechanical activity after 8 hours of preservation.
Conclusions:
- Older donor hearts exhibit reduced ischemic tolerance, particularly after prolonged cold preservation.
- The endothelium of older donor hearts is more susceptible to ischemia/reperfusion injury.
- These findings highlight the importance of ischemic time and donor age on early graft function and potential long-term outcomes.
Background And Aims:
Both advanced donor age and prolonged ischemic time are significant risk factors for the 1-year mortality. However, its functional consequences have not been fully evaluated in the early-phase after transplantation; even early graft dysfunction is the main determinant of long-term outcome following transplantation. We evaluated in vivo left-ventricular (LV) cardiac and coronary vascular function of old-donor grafts after short and prolonged cold ischemic times in rats 1 h after heart transplantation.
Methods:
The hearts were excised from young donor (3-month-old) or old donor (18-month-old) rats, stored in cold preservation solution for either 1 or 8 h, and heterotopically transplanted.
Results:
After 1 h of ischemic period, in the old-donor group, LV pressure, maximum pressure development (dP/dt max), time constant of LV pressure decay (τ), LV end-diastolic pressure and coronary blood flow did not differ compared with young donors. However, endothelium-dependent vasodilatation to acetylcholine resulted in a significantly lower response of coronary blood flow in the old-donor group (33 ± 4 vs. 51 ± 15 %, p < 0.05). After 8 h preservation, two of the old-donor hearts showed no mechanical activity upon reperfusion. LV pressure (55 ± 6 vs. 72 ± 5 mmHg, p < 0.05), dP/dt max (899 ± 221 vs. 1530 ± 217 mmHg/s, p < 0.05), coronary blood flow and response to acetylcholine were significantly reduced and τ was increased in the old-donor group in comparison to young controls.
Conclusions:
During the early-phase after transplantation, the ischemic tolerance of older-donor hearts is reduced after prolonged preservation time and the endothelium is more vulnerable to ischemia/reperfusion.
