Since 1991, the Spanish Heart Transplantation Registry (Registro Español de Trasplante Cardiaco [RETC]) has published a description of the clinical and surgical characteristics and general results of heart transplantation procedures performed in Spain (Appendix).1–23 The present article describes these data and includes patients undergoing transplantation prior to December 31, 2012. The major strengths of the RETC lie in its inclusion of practically all heart transplantation procedures in hospitals throughout Spain since May 1984, independently of their characteristics and outcomes. Moreover, data are collected prospectively and are recorded in a single database, following criteria unanimously agreed on by all heart transplantation teams.

The RETC is now nearly a quarter of century old and has undergone an increase in volume as a consequence of the greater number of transplantation centers, the accumulation of procedures performed and, especially, their complexity. The great strength of the RETC lies in successfully creating a registry of all heart transplantations performed in Spain since the first procedure in 1984 and in having adapted to changes in the procedure and in knowledge of transplantation over time. The continued efforts of all the Spanish programs have allowed the use of an online application to be implemented this year; this application enables RETC data to be updated in real time. This undoubtedly constitutes a very important means of improving the quality and productivity of the RETC. Sharing agreed, standardized, prospective data constitutes a research instrument and, above all, a clinical tool of immense value. This is particularly so in contexts such as heart transplantation in Spain, where implementation of the procedure is nationwide (18 centers currently have active programs) and, consequently, the volume per center is low. Obviously, only analysis of country-wide data can guarantee a minimum of consistency in the findings.

In 2012, 247 transplantations were performed—in line with figures for recent years. The falling number of transplantations since the peak reached in the late 1990s is common throughout Europe.24 The causes are probably multifactorial and complex. Without doubt, they include the scarcity of optimal donors—principally from traffic accidents—and the improved prognosis of the most frequent heart diseases; in the last decade, drug and instrumental treatments have been consolidated and delay the need for transplantation.

Analysis of time trends in the characteristics of transplantation may shed light on changes in clinical practice over time. Firstly, data show a gradual worsening in the clinical profile of recipients. The last 5 to 10 years have seen increases in the percentage of patients who are older, have worse renal function, more insulin-dependent diabetes mellitus, and are under mechanical ventilation. All these factors are known to affect short- and long-term prognosis.24 Similarly, the number of emergency procedures has increased, reaching nearly 40% in the last 4 years. We can only speculate about the causes of these trends. On the one hand, the increased experience of transplantation programs may have led to greater risk-taking with the inclusion of patients with a worse clinical profile. On the other hand, the tremendous advances in the medical and instrumental treatment of heart disease in the last 20 years have meant that patients receive prognoses similar to those for transplantation—until quite poor functional status has been reached25—which generally delays their inclusion on waiting lists and the performance of transplantation.

Similarly, criteria for donation have gradually been expanded. This can be seen in the significantly older mean age of donors and the percentage of older donors (>45 years) as well as in the increase in donors who have died from a stroke, frequently associated with a greater incidence of arteriosclerosis. This trend probably reflects the struggle of transplantation programs in the face of a growing scarcity of optimal donors.

The same tendency described for recipient and donor profiles is also evident in the surgical procedure, as the gradual lengthening of ischemia time seems to indicate. Remarkably, in the last 4 years, up to 29% of recipients had >4 h of ischemia time—which is considered the limit to ensure adequate graft viability. To date, we cannot put these delays down to the gradual worsening of logistic conditions affecting procedures—at least not in general. However, this worsening could be explained by an increasingly greater willingness to accept organs from geographically distant areas—especially for urgent transplantation—and by the effect of performing transplantations on patients with medium- and long-term circulatory assist devices, which occasionally lead to less predictable surgical procedures.

Nevertheless, the general results for mortality—following the first 10 years of activity (1984-1994), which could be classified as the founding years—have remained relatively stable and compare favorably with international registry data.24 Nonetheless, in general, surgical mortality has remained relatively high, making it a clear objective for improvement. We will have to see whether the coming years confirm a positive trend in this mortality, as data for 2012 appear to suggest.

The most remarkable innovation of the last 5 years is probably the increasing use of circulatory assist devices prior to transplantation since, in 2012, these have surpassed in percentage terms the use of the traditional intraaortic counterpulsation balloon. In Spain, these devices began to be deployed much later than elsewhere, very probably due to logistic reasons, mainly–but not always–due to economic limitations. It is still too early to determine the impact of these devices both on recruiting potential transplantation recipients and the status of recipients when they undergo the procedure and, therefore, their prognosis. Implementing these complex techniques involves a learning curve related, firstly, with an appropriate match between patient and technique, secondly, with managing these special clinical circumstances, and, thirdly, with establishing the ideal time to perform the transplantation following implementation. It is to be hoped that the individual effort and general shared knowledge derived from the transplantation centers through RETC support will lead to improved results in the coming years. Moreover, we predict that the greater use of circulatory support will lead to changes in selection criteria for emergency transplantation—an issue that is constantly changing and evolving and has significant repercussions on policy in assigning grafts.

We also detected time-scale changes in immunosuppression. Currently, induction is widely used, fundamentally with the administration of interleukin-2 inhibitors and, particularly, basiliximab. These potent inductors allow the introduction of calcineurin inhibitors to be delayed—an increasingly widespread practice in the context of peritransplantation kidney failure. In addition, their level of clinical tolerance is excellent, which contrasts with now obsolete drugs such as OKT3. Initial immunosuppression continues to be based on traditional triple therapy, although we have found a clear change in the selection of calcineurin inhibitors toward tacrolimus and in that of antiproliferative agent towards mycophenolate mofetil, to the detriment of cyclosporine and azathioprine, respectively. Furthermore, the use of m-TOR inhibitors (sirolimus and, above all, everolimus) has increased to reach the current total of 23% of patients, in the context of increasingly individualized immunosuppression therapy aimed at preserving renal function and preventing graft vascular disease and post-transplantation neoplasia.

Heart transplantation is currently a well-established therapeutic treatment for selected patients with advanced-stage heart failure who are not candidates for other treatments. Although the clinical context in which this procedure is used has become ever more complex, the results remain within international parameters. However, potential improvements can be made in issues such as periprocedural mortality, the adequacy of immunosuppression, and long-term preventative care for major causes of mortality such as tumors, graft vascular disease, infections, and kidney failure. In the coming years, efforts must be maintained to effectively and efficiently introduce the pre- and postprocedural use of circulatory support devices into the standard management of patients suitable for heart transplantation.

The RETC is partly funded by an unconditional grant from Novartis.

F. González-Vílchez: remuneration for presentations: Astellas, Novartis, Roche, Pfizer. Expenses associated with travel, accommodation or attendance at scientific meetings: Roche, Astellas, Novartis.