The current report provides data on transplants performed in 2022. In addition, we have analyzed the changes over time in the characteristics of the series in the previous decade, stratified by 3-year periods (2013-2015, 2016-2019, and 2020-2021). The percentages of some characteristics in the last decade were analyzed by year, such as urgent transplants, type of pretransplant circulatory support, and donor age.

The inclusion and data updating procedures of the Spanish heart transplant registry have not undergone major changes from previous years.2 Crucially, the Spanish heart transplant registry was established as a registry of procedures (transplants performed), not of patients. Accordingly, a retransplanted patient generates 2 distinct records that are analyzed separately. Participation in the Spanish heart transplant registry is voluntary for all transplant teams operating in Spain. In a change from previous years, Hospital Universitario La Paz (Madrid) started in 2022 to include adult patients (age at transplant ≥ 18 years) undergoing transplants for congenital heart disease. Accordingly, the registry shows the same number of Spanish transplant centers, even though only 1 of these centers now performs pediatric transplants alone (table 1).

The total numbers and types of transplant performed in 2022 and in the entire series are summarized in table 2. In 2022, 311 transplants were performed; most (n=300) were de novo heart transplants. Thus, 9 retransplants (2.9%) were performed, as well as 1 combined heart-kidney transplant and 4 combined transplants (2 de novo heart-kidney transplants, 1 de novo heart-liver transplant, and 1 heart-kidney retransplant). By age, 28.9% of recipients (90 transplants) were older than 60 years and 11.6% (n=36) were younger than 18 years. Overall, the Spanish heart transplant registry has recorded 9673 procedures (figure 1).

Figure 1.

Annual number of transplants (1984-2022), total and by age group.

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Continuous variables are expressed as mean±standard deviation, whereas categorical variables are expressed as percentages. Differences among time periods were analyzed using a nonparametric test for temporal trends (Kendall τ) for categorical variables and a Wilcoxon test for trends for continuous variables.3 Survival curves were calculated using the Kaplan-Meier method and were compared using a log-rank test. Differences were considered statistically significant at P<.05.

In 2022, 311 transplants were performed, 9 (3.0%) more than in the previous year, which stabilizes the number of procedures performed at about 300 per year (figure 1). The main recipient characteristics in 2022 and from 2013 to 2022 are summarized in table 3. In the overall population, the mean recipient age has shown no significant changes in the last 10 years and remains 49.0 years (48.0 years in 2022). Similar stability was observed in recipients ≥ 18 years at transplant (53.2 years in the last decade, 53.3 years in 2022). There was a nonsignificant tendency for a higher proportion of female recipients in the last decade, which reached 28.9% in 2022. Similarly, a tendency was detected for improved clinical status among recipients, as well as for a lower proportion of patients with diabetes or with elevated bilirubin at transplant. This tendency was significant for pulmonary vascular resistance, which has decreased up to 2.0 Wood units, a finding maintained in 2022. The trend was confirmed in 2022 for a lower percentage of urgent transplants (37.6%), and the difference was significant compared with 2013 (P<.001) (figure 2). Since 2019, this percentage has consistently been less than 40%. The data from 2022 confirmed the highly significant temporal trends in the distribution of the type of immediate pretransplant circulatory support devices used (figure 3). In the last 5-year period, 562 patients (37.8% of the total number of patients transplanted in this period) were transplanted with some type of circulatory assist device. Most of these devices were continuous-flow ventricular assist devices (367 patients; 24.7% of all recipients), followed by extracorporeal membrane oxygenation (ECMO) devices (133 patients; 8.9%) and pulsatile ventricular assist devices (46 patients; 3.1%). The maginal use of balloon pump (16 patients; 1.1%) was maintained during this period. In 2022, these percentages largely matched those of the last 5-year period.

Figure 2.

Annual percentage of urgent transplants vs the total number (2013-2022).

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Figure 3.

Distribution of the type of pretransplant circulatory support by year (2013-2022). ECMO, extracorporeal membrane oxygenation; VAD, ventricular assist device.

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Donor and surgical procedure characteristics are summarized in table 4. Donor age has remained stable in the last decade (figure 4), at an average of 42.5±15.2 years in the last 10 years (41.1±16.3 years in 2022). Similar stability was seen for the percentage of suboptimal donors, that is, donors older than 45 years old, which has been 52.2% on average in the last decade (49.5% in 2022). At least until 2021, the only statistically significant characteristic was the use of larger donors (P for trend=.04), although this has not resulted in a particularly unfavorable donor-to-recipient weight ratio (> 1.2 or <0.8).

Figure 4.

Annual changes in donor age and the percentage of donors older than 45 years (2013-2022). 95%CI, 95% confidence interval.

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The most pertinent data regarding the donation process, which were consolidated in 2022, were donation after circulatory death (asystole) and ABO-incompatible transplantation. Donation after circulatory death was performed in 52 patients in 9 centers (4 patients in 2020, 11 in 2021, and 37 in 2022). In addition, 15 ABO-incompatible transplants were performed from 2018 to 2022, all in pediatric patients (4 in 2018, 2 in 2019, 2 in 2020, 4 in 2021, and 3 in 2022).

As seen in previous reports, the mean ischemia time has significantly decreased in the last 10 years (table 4) and was slightly longer than 3hours in 2022. This decrease was largely due to an increase in the number of procedures performed with an ischemia time less than 2hours. We continue to see significant growth in the bicaval technique, used in more than 80% of patients in 2022.

Table 5 summarizes the trends related to the drugs used for induction immunosuppression. Data similar to those of the most recent years were obtained in 2022, although significant tendencies can still be detected when the comparison is extended to the beginning of the previous decade. Induction with anti-CD25 (currently only performed with basiliximab) and triple therapy with tacrolimus, mycophenolate mofetil (or mycophenolic acid), and steroids form the basis of the induction immunosuppressive therapy in the overwhelming majority of patients.

Survival in the 2013 to 2022 period was 81.4% in the first posttransplant year and 73.4% at 5 years. This rate is significantly higher than that seen in the entire historic series (figure 5A). No significant improvement in survival was detected in the last decade (figure 5B). However, numerically, 1-year survival has constantly improved: 79.7% from 2013 to 2015, 81.7% from 2016 to 2018, and 82.2% from 2019 to 2021. Some of the univariable predictors of mortality are summarized in table 6. The factors most strongly associated with mortality were those related to the recipient's pretransplant clinical status (need for advanced circulatory support or mechanical ventilation) and to comorbidity (age, pretransplant infection, diabetes or pretransplant renal failure, ischemic etiology).

Figure 5.

A: comparison of survival curves between the 2013 to 2022 and 1984 to 2012 periods. B: comparison of survival curves from 2013 to 2021 by 3-year period.

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The specific causes of death in the first 5 posttransplant years were primary graft failure (23.2%) and infection (21.0%) (figure 6). As expected, the main causes of death were primary graft failure in the first posttransplant month (39.3%) but infection between 2 and 12 months (44.9%). Acute rejection was the cause of death in 7.1% of patients between the 2nd and 12th posttransplant months. Although rejection was the fourth cause of death in the first 5 posttransplant years, its prevalence was not negligible after the first year (14.6% of patients). After the first posttransplant year, the most frequent causes of death were graft vascular disease/sudden cardiac death (23.8%) and cancer (19.5%).

Figure 6.

Main causes of death by time since transplant in the 2013 to 2022 period. GVD/SCD, graft vascular disease/sudden cardiac death. Each cause of death is reported as a percentage of total patient deaths in the specific period.

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The last decade has shown a significant decrease in rejection as the cause of death in the first year (from 7.3% from 2013 to 2015 to 2.6% from 2019 to 2021), although an uptick was detected in 2022 (4.2% of all deaths). However, the prevalences of primary graft failure and infections as causes of death have remained stable in the last 10 years (figure 7).

Figure 7.

Changes over time in the main causes of death in the first posttransplant year in the 2013 to 2022 period by 3-year period.

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This study has the typical limitations inherent to a registry of unaudited reports.