Heart transplantation is going through a particularly interesting period in Spain. This is not only because activity has increased, but also because the clinical landscape has changed profoundly: donors are older and have more comorbidities, recipients present with increasingly complex profiles, donation after circulatory death has become a real source of expansion, and mechanical circulatory support now plays a central role in the trajectory of candidates for transplantation.

In this context, the 1st Cardiac Transplantation Symposium, held within the 9th Congress of the Spanish Transplantation Society in A Coruña, provided a fairly accurate snapshot of the current situation: a strong, well-organized system with good outcomes, but one that now faces increasingly nuanced decisions. The question is no longer simply how to increase the number of available organs, but how to select recipients more appropriately, preserve grafts more effectively, stabilize patients better, and perform transplantation under more favorable conditions.

The underlying message could be summarized as follows: the success of heart transplantation no longer depends on a single surgical act or an isolated technology. It depends on a chain of decisions that begins with donation, continues through recipient assessment, moves on to graft preservation, and is often decided in the days preceding transplantation.

The main clinical and organizational messages from the symposium are summarized below by thematic area.

1.Spain remains in a privileged position, but the model has become more demanding

The first major message of the symposium was the excellent current status of donation and transplantation in Spain. The organization of the system, the role of the ONT, in-hospital coordination, and the ability to adapt have made it possible to sustain a level of activity that is difficult to match internationally.

In heart transplantation, the data presented show a highly relevant evolution. Spain ranks among the countries with the highest activity per million population and has reached historic figures, with an increasing contribution from donation after circulatory death. In 2025, Spain approached 400 heart transplants, with very substantial growth in procedures from donors after circulatory death.

However, the most important point may not be the absolute number alone. What sets the Spanish system apart is that it has managed to grow without relying on the ideal donor. In contrast to other countries, where cardiac donors tend to be younger, Spanish donors are often older and have a greater burden of comorbidity. This requires a much more sophisticated culture of assessment, preservation, and selection.

The changes introduced in 2023 to urgent prioritization criteria were another key point. Status 0 is now divided into 0A, for patients with biventricular support or more severe clinical situations, and 0B, for patients with univentricular support. This classification aims to rationalize access to urgent transplantation and reduce futility. In practice, it introduces an essential idea: the device matters, but the patient’s biological status matters even more.

Although patients transplanted under urgent status still carry a higher early risk than elective recipients, the data presented by the Spanish Registry suggest that the change in criteria has not worsened outcomes and may have contributed to improved early survival, probably by avoiding transplantation in patients with multiorgan failure, prolonged mechanical ventilation, or an already excessively deteriorated clinical condition.

2. Donation after circulatory death has changed the landscape

One of the main protagonists of the symposium was cardiac donation after circulatory death. Not so many years ago, it seemed to be a technical, ethical, and logistical frontier. Today, it has become an essential part of the growth of the national program.

In 2025, 137 heart transplants from donors after circulatory death were performed, approximately 35% of the total. This figure reflects not only volume, but also organizational maturity.

From a technical standpoint, the symposium emphasized several fundamental aspects required to make this strategy safe: normothermic regional perfusion, neurologic protection, division or clamping of the supra-aortic vessels, and monitoring during the procedure. These are not minor technical details; they are the basis that allows recovery of cardiac function without compromising safety or the ethical principles of the process.

However, the expansion of donation after circulatory death also requires caution. In multiorgan procurement, the heart is not the only organ involved. The lungs and liver have different sensitivities to time, inflammation, extracorporeal circulation, and congestion. Therefore, the growth of donation after circulatory death requires a truly multidisciplinary approach.

The practical message is clear: donation after circulatory death is no longer an emerging technique, but a consolidated tool. Precisely for that reason, it must not be trivialized. Its success depends on strict protocols, trained teams, and excellent surgical coordination.

3. The current recipient requires us to move beyond simple dogmas

Candidates for heart transplantation are increasingly complex. Age, history of malignancy, renal failure, liver disease, immunologic sensitization, and anticoagulation are now common components of the assessment.

One of the most interesting points was the change in approach to patients with a history of cancer. The old dogma of systematically waiting 5 disease-free years seems too rigid for contemporary medicine. Risk must be individualized according to tumor type, stage, biology, disease-free interval, and the patient’s clinical status. Not all tumors carry the same risk, nor do they affect posttransplant prognosis in the same way.

The discussion on combined transplantation was also highly relevant. Advanced renal failure and significant liver disease cannot be interpreted simply as accompanying comorbidities. In selected patients, they decisively influence the outcome of isolated heart transplantation. The question is not only whether the patient can “tolerate” a heart transplant, but whether an isolated heart transplant will truly solve the problem.

Another highly practical issue was antithrombotic therapy in patients on the waiting list. Anticoagulated patients are common, and the balance between thrombotic safety and perioperative bleeding risk remains delicate. In this context, experience with dabigatran and idarucizumab in selected patients was highlighted, in contrast to the uncertainties and potential problems of andexanet alfa, the reversal agent for factor Xa inhibitors such as apixaban and rivaroxaban, in the setting of heart transplantation.

Overall, this session left a clear lesson: recipient selection is not about applying a rigid list of contraindications, but about estimating risk, benefit, and opportunity. Modern heart transplantation requires fewer dogmas and more expert committees.

4. Preservation is no longer just “cooling and transporting”

Graft preservation was presented as an increasingly active and biologic process. Traditionally, it has been explained in linear terms: less ischemia is better, shorter time is better, and a younger donor is better. All of this remains true, but it is no longer enough.

Primary graft dysfunction does not depend only on the organ or on ischemic time. It results from the interaction between a vulnerable graft and a potentially hostile recipient: inflamed, critically ill, supported with circulatory devices, receiving catecholamines, vasoplegic, or with multiorgan dysfunction.

In this context, technologies such as the Paragonix SherpaPak represent an important intermediate step between conventional cold storage and ex vivo perfusion platforms. Their value lies not only in transporting the heart, but in maintaining a more stable and controlled temperature during transport, reducing thermal variability and avoiding both excessive cooling and the fluctuations typical of conventional transport. In several Spanish centers, these advanced preservation strategies are already part of routine practice and, in the programs with the greatest experience, have been associated with a reduction in primary graft dysfunction.

This change shifts the focus. The issue is no longer only how long the heart has been outside the body, but how it is preserved, what biologic injury it accumulates, how it is reperfused, and into what environment it is implanted. Reperfusion, particularly the first few minutes after unclamping, remains a decisive and still insufficiently standardized phase.

New technologies for preservation, perfusion, and ex vivo reconditioning open a different era. The future will probably not be limited to transporting organs, but will involve monitoring, protecting, and even modifying them before implantation.

5. Mechanical circulatory support: keeping the patient alive is not enough

The session on mechanical circulatory support and transplantation was one of the most closely connected to the current dilemmas in advanced heart failure. The ASIS-TC registry showed that urgent transplantation with short-term devices is feasible and has allowed many critically ill patients to undergo transplantation. However, it also confirmed that early mortality remains relevant, particularly in the sickest patients, those with mechanical ventilation, renal dysfunction, elevated lactate, or the need for ECMO.

This is where one of the most important conceptual changes emerges: mechanical circulatory support should not be understood as a static snapshot, but as a trajectory. It is not only which device the patient has, but where the patient comes from, where the patient is going, and what is being achieved during support. Is lactate decreasing? Is renal or liver function improving? Can the patient be extubated? Can the patient be mobilized? Are we unloading the left ventricle? Are we preventing the patient from reaching transplantation on ECMO, ventilated, and with systemic inflammation?

The French experience with “awake ECMO” is particularly interesting because it arises in a context different from ours. In France, where Impella 5.5 is not available or does not have the same level of reimbursement, some centers have optimized peripheral VA-ECMO as a bridge to transplantation. The message is not that ECMO is harmless, but that it can provide good results when used within a very strict strategy: appropriate selection, early extubation, mobilization whenever possible, absence of established organ failure, limited support duration, and LV unloading if congestion or ventricular distension develops. Ultimately, the goal is to turn ECMO into a short, awake, and controlled bridge to transplantation.

In our setting, with the progressive incorporation of Impella 5.5, this experience should be interpreted with nuance: the issue is not to copy the French model, but to decide which patients truly require ECMO and in whom earlier LV unloading may prevent a more aggressive trajectory.

In selected candidates, Impella 5.5 allows us to reconsider the bridge to transplantation: it not only provides flow, but also unloads the left ventricle, facilitates axillary access, enables extubation, mobilization, and rehabilitation, and can turn support into a strategy for clinical recovery, not merely survival until an organ becomes available.

Data from the 2025 Spanish Heart Transplant Registry reflect this change. After the criteria introduced in 2023, status 0 is divided into 0A, for biventricular support or greater severity, and 0B, for univentricular support. In status 0B, Impella 5.5 has already become the predominant device: 45 patients, representing 64.3% of the group. In addition, among specified Impella supports, the 5.5 accounts for almost all cases: 45 of 47, approximately 96%. This is a highly illustrative finding of the shift toward more stable left-sided support, with axillary access and the potential for extubation, mobilization, and rehabilitation before transplantation.

The practical question should no longer be simply “ECMO or Impella,” “short- or long-term support,” or “status 0A or 0B.” The real question is: what trajectory are we building for this patient?

COMMENTARY:

The overall impression from the symposium is that Spanish heart transplantation is in a phase of strength, but also of greater complexity. We have learned to generate more donors, incorporate donation after circulatory death, improve preservation, stratify urgency, and support patients with increasingly sophisticated devices. But every advance creates a new responsibility.

For years, the major challenge in heart transplantation was organ shortage. That problem still exists, but it no longer explains the full complexity of the current landscape. Today, the challenge is broader: which donor we accept, which recipient we select, how we protect the graft, how we manage the waiting list, and how we prevent circulatory support from becoming a prelude to multiorgan failure.

Donation after circulatory death captures this new era well. It has expanded the donor pool and placed Spain in a leading position, but its success does not depend on a single technical maneuver. It depends on a system-wide culture: coordination, timing, neurologic protection, surgical expertise, preservation, and subsequent graft assessment.

A similar process is occurring with the recipient. Modern medicine has removed many barriers that once seemed absolute. A history of cancer no longer necessarily means exclusion. Renal or liver failure does not always contraindicate transplantation, but it does require consideration of combined transplantation. Immunologic sensitization does not close the door, but it demands strategy. Individualization does not mean improvisation; it means making better decisions.

Regarding mechanical circulatory support, the symposium reinforces an increasingly evident idea: the device is not the full treatment; the treatment is the strategy. In this sense, Impella 5.5 is beginning to occupy its own space in our setting, particularly as a left-sided support device capable of providing sufficient flow, unloading the ventricle, allowing axillary access, and facilitating extubation, mobilization, and rehabilitation. The first Spanish multicenter data and the recent evolution of the Spanish Registry point in the same direction: in a transplant-oriented system, the goal is not merely to support the patient, but to keep the patient transplantable. Therefore, ECMO, Impella, CentriMag, and LVAD should not be viewed as isolated compartments, but as tools within a clinical sequence: ECMO when full cardiopulmonary support is required, Impella 5.5 when LV unloading and a more physiologic trajectory are sought, and transition or de-escalation strategies when the aim is to reach transplantation in better condition.

This way of thinking requires earlier action. If we wait until the patient has accumulated prolonged mechanical ventilation, renal failure, hyperbilirubinemia, infection, or systemic inflammation, transplantation may become a late solution for an already irreversible problem. The opportunity lies in identifying the phenotype earlier, choosing support more appropriately, unloading the ventricle when needed, extubating, mobilizing, and rehabilitating.

Graft preservation adds another layer of complexity. The donor heart can no longer be understood as an object that is cooled and transported. It is a living, vulnerable organ that arrives in a recipient who is often inflamed and critically ill. The biology of the graft and the biology of the recipient meet in the operating room, and a substantial part of the outcomes we still cannot predict well probably lies there.

Current heart transplantation increasingly resembles less an isolated intervention and more a chain of decisions. We may have an excellent donor and lose the outcome because of poor recipient selection; we may have a good recipient and lose the graft because of poor preservation; we may have a sound indication and compromise the trajectory through delayed or poorly planned support.

The major lesson from the symposium is that transplantation begins long before the left atrial suture and ends long after separation from cardiopulmonary bypass.

The challenge is no longer only to transplant more. It is to transplant better. To achieve this, we will need to arrive earlier, select more precisely, preserve more intelligently, and build clinical trajectories that allow the patient not only to reach the organ, but to arrive at transplantation in a condition that allows them to benefit from it.

REFERENCE:

1st Cardiac Transplantation Symposium. Held within the 9th Congress of the Spanish Transplantation Society 2026. A Coruña, May 14, 2026. PALEXCO Exhibition and Congress Center. Official program available.

Martínez-Comendador JM, Martín Gutiérrez E, Ortiz Berbel D, Alcalde LG, Pedraz Prieto Á, Muñoz Guijosa C, et al. Impella 5.5 support in severe cardiogenic shock: outcomes from the first Spanish multicentre cohort in heart transplant centres. Interdiscip Cardiovasc Thorac Surg. 2026 May 13:ivag137. doi: 10.1093/icvts/ivag137. Epub ahead of print.