Donation after the circulatory determination of death (DCD; controlled donation after asystole in our setting) has earned a place of its own among the strategies used to widen the pool of hearts available for transplantation. Its value, however, goes beyond adding volume: it forces us to rethink the entire chain, from donor selection to recipient choice, with retrieval technique and graft preservation in between.

Spain embodies this new stage well. Cardiac DCD has grown considerably, built on a solid organizational model, in-hospital coordination, and growing experience with thoraco-abdominal normothermic regional perfusion. But the challenge has changed in nature: it is no longer just about transplanting more, but about doing so with donors that are increasingly less than ideal and recipients that are increasingly complex.

Against this backdrop, the study by Louca and colleagues is especially timely, because it compares the European and US experience in DCD heart transplantation and helps clarify how organizational models, donor profile, and retrieval technique shape outcomes.

This is an observational, retrospective, multicenter, international study based on the Outcomes after DCD Cardiac Transplantation Database. It included 504 patients who underwent DCD heart transplantation at 22 centers in Belgium, Spain, the United Kingdom, and the United States. The primary aim was to compare 1-year survival between European and US centers; the secondary aims were short- and mid-term survival, severe primary graft dysfunction (PGD), acute cellular rejection, and the need for mechanical circulatory support (MCS) after transplantation.

The European cohort comprised 223 patients and the US cohort 281. European donors were significantly older than their US counterparts (37 vs 28 years; p < .001), whereas US recipients were older, had more diabetes, and more often received mechanical circulatory support before transplantation.

One-year survival was higher in the United States (91.8% vs 86.6%; p = .043), although no significant differences were seen at 30 days or at 3 years. The detail is where it matters: when outcomes were broken down by retrieval technique, this difference concentrated in cases of direct procurement and perfusion (DPP), where 1-year survival was higher in the United States (91.9% vs 82.6%; p = .021). By contrast, among patients managed with thoraco-abdominal normothermic regional perfusion (taNRP) — where the heart is reperfused and assessed within the donor before retrieval — survival was similar between Europe and the United States.

European recipients required post-transplant MCS more often (17.9% vs 11%; p = .03), although geographic location did not behave as an independent predictor of severe PGD in the adjusted models. No relevant differences in acute cellular rejection were observed between the two regions.

The authors conclude that DCD heart transplantation is a safe and effective strategy in both Europe and the United States, despite relevant differences in donors, recipients, retrieval techniques, and clinical outcomes. They stress the need to keep gathering international data to optimize the use of these grafts.

COMMENTARY:

The main value of this study is not to prove that DCD heart transplantation works (we already knew that) but to show that it can work across very different models. Europe and the United States differ in more than geography: they differ in organization, donor profile, acceptance criteria, retrieval technique, and probably in clinical culture as well.

We recently discussed, in Heart Surgery Today, some of the ideas presented at the 1st Cardiac Transplant Symposium, held in A Coruña within the 9th Congress of the Spanish Transplant Society. It became clear there that heart transplantation in Spain is going through a period of high activity, but also of greater clinical demand: older donors, more complex recipients, a larger role for mechanical circulatory support, and a growing need to optimize graft preservation. In 2025 we approached 400 heart transplants in our country, 137 of them from donors after asystole (roughly 35% of the total). With those figures on the table, a study like this one reads close to home, not from the sidelines.

The first message is reassuring. Overall results are good in both regions. Although 1-year survival was higher in the United States, there were no significant differences at 30 days or 3 years, and the overall survival curve did not separate the two groups. The study should therefore not be read as a contest between systems, but as confirmation that DCD can be consolidated safely when experience, appropriate selection, and well-structured logistics are in place.

The underlying difference lies in the donor. European donors were older and more often died from stroke; in the United States younger donors predominated, with a higher proportion of trauma or anoxia. And this is no minor point: not every DCD heart is the same heart. A young graft probably tolerates ischemia, reperfusion, and handling during preservation better. An older one arrives with less reserve and calls for a more careful retrieval strategy.

This connects directly with the Spanish situation. Our growth in cardiac DCD has not been built on the young, ideal donor. That is why the question is no longer only whether the heart can be used, but how to retrieve, assess, and preserve it so it can be implanted with confidence.

The most interesting finding appears in the DPP subgroup, where 1-year survival was better in the United States. A reasonable reading is possible: that this strategy performs especially well when the donor is young and at low cardiovascular risk, whereas in Europe, with older donors, direct procurement and ex situ perfusion would leave the graft more exposed. The study does not prove this, but the hypothesis holds up clinically.

taNRP emerges here as a particularly attractive tool. In this subgroup, survival was similar between Europe and the United States despite baseline differences. This suggests that regional normothermic perfusion helps recover and better assess more complex DCD hearts. Its value lies not only in restoring perfusion, but in allowing one to see the heart beating within the donor and judge it under physiological conditions before retrieval.

Recent Spanish experience points in exactly that direction: donation after asystole, strict protocols, neurological protection, surgical coordination, and regional normothermic perfusion as parts of a global strategy. It is these technical and organizational details — not the technique in the abstract — that turn a complex procedure into a reproducible program.

Another relevant finding is the greater need for post-transplant MCS in Europe. It may reflect more severe primary graft dysfunction, though here we should ease off: the use of ECMO or ventricular assistance also depends on each center’s threshold, on device availability, and on postoperative management culture. Even so, the finding fits the idea that the European model takes on more demanding donors from the outset.

It is also interesting that US recipients were older, with more diabetes and more pre-transplant MCS, and yet without worse overall results. This defuses an overly restrictive reading of DCD: these grafts need not be reserved for low-risk recipients. But expansion is not permissiveness. The combination of a marginal donor, a less favorable technique, and a severely deteriorated recipient remains, in all likelihood, the worst-case scenario.

The limitations are clear. A retrospective, observational study, with the selection bias that entails. The participating centers are expert programs, so the results cannot simply be transferred to centers on the learning curve. Moreover, Europe and the United States are not homogeneous blocs, and relevant variables are missing, such as implantation time, mild or moderate primary graft dysfunction, intra-aortic balloon pump use, or finer details of preservation.

However, it cannot be concluded that taNRP is universally superior to DPP. The choice of one strategy over the other was influenced by legislation, stand-off periods after circulatory arrest, technological availability, local expertise, and donor characteristics. Moreover, the taNRP and DPP categories encompass procurement and preservation protocols that are not necessarily identical across countries and centers, with relevant differences in ischemic times, graft reperfusion, and the use of ex situ perfusion or static cold storage. Therefore, regional comparisons should not be interpreted as a direct head-to-head assessment of two fully standardized techniques. The practical message is more modest, but also more useful: the recovery strategy should be tailored to the donor profile and the specific context of each transplant program.

Taken together, the article fits the current moment of heart transplantation in Spain very well. Donation after asystole is no longer a promise, but a consolidated reality. The challenge now is not to do more of it, but to do it better: select the donor better, choose the most appropriate retrieval strategy, preserve the graft better, and optimize the recipient before implantation.

The final lesson is simple: DCD heart transplantation is not an isolated technique, but a program strategy. Its success depends on a coordinated chain of decisions. Spain starts from a favorable position thanks to its organization and its experience in donation, but the room for improvement lies in fine-tuning still further the matching between donor, graft, and recipient. Recovering the heart is only the first note; what decides the outcome is the whole score.

REFERENCE:

Louca JO, Öchsner M, Shah A, Schlendorf K, Lima B, Wang CC, et al.; ODDCAT collaborators. A comparison of DCD heart transplantation in Europe and the United States: A multi-center, retrospective study. J Heart Lung Transplant. 2026 Apr 16:S1053-2498(26)01838-3. doi: 10.1016/j.healun.2026.04.007.