Donation after circulatory death improves probability of heart transplantation in waitlisted candidates and results in post-transplant outcomes similar to those achieved with brain-dead donors

Donation after circulatory death heart transplantation: The French perspective

Heart transplantation is the gold standard treatment for patients with advanced heart failure in the absence of contraindications. In recent years, the shortage of heart donors has led to a resurgence in the use of hearts from donation after circulatory death (DCD) donors after withdrawal of life-sustaining treatment. In these donors, death is determined by the cessation of spontaneous circulation and respiration for≥5minutes and is confirmed by neurological criteria. Two heart procurement procedures are used, namely direct procurement and perfusion (DPP) and procurement after thoracoabdominal-normothermic regional perfusion (TA-NRP). Donor hearts procured using TA-NRP are reperfused and assessed inside the donor and preserved with static cold storage or ex situ machine perfusion. With DPP, hearts are reperfused and assessed ex situ with a perfusion machine. The ischaemic time before heart reperfusion is shorter with TA-NRP than with direct procurement followed by ex situ perfusion. The TA-NRP technique allows for the assessment of the function of the donor heart. Numerous studies have reported similar survival rates between recipients who have received hearts from DCD and donation after brain death (DBD) donors. The incidence of severe primary graft dysfunction varies according to the team's learning curve and the country. The heart utilization rate is greater with TA-NRP procurement than DPP. This article describes the two donor heart procurement techniques, provides a summary of the relevant literature on the outcomes of transplantation from DCD donors and reports the position of a working group, convened by the French national transplant agency, on donor and recipient selection.

Spanish Center's Early Experience With Donation Following Circulatory Death in Heart Transplantation

Heart transplantation using donation after circulatory death (DCD) has recently re-emerged alongside donation after brain death (DBD). This technique can potentially increase the number of available cardiac grafts. However, its clinical outcomes remain limited. We compared data from patients who received grafts from DCD versus DBD between 2012 and 2023. During this period, 131 adult patients underwent isolated heart transplantation. Of these, 25 (19%) were DCD donors. Donation after circulatory death donors were predominantly local (66% vs. 42%; p = 0.027). Donation after circulatory death graft recipients had fewer ventricular assist devices (12% vs. 35%; p = 0.025) and were less frequently urgent (12% vs. 39%; p = 0.009). Donation after circulatory death grafts had shorter myocardial ischemia and extracorporeal circulation times than DBD grafts (70 min [63.5-91] vs. 168 [83-219]; p < 0.001); (90 min [78-103) vs. 120 [96-148], p < 0.001). We observed no significant differences in the incidence of primary graft failure (16% vs. 22%; p = 0.526) or hospital mortality (8% vs. 14%; p = 0.410) between both groups. In conclusion, cardiac DCD demonstrates hospital outcomes comparable to those of cardiac DBD. Further long-term follow-up of these patients is necessary to determine their rejection, graft vascular disease, and mortality outcomes.

Association of agonal phase duration with heart utilization and post-transplant outcomes in donation after circulatory death heart transplantation

BACKGROUND

This study evaluates the impact of the agonal phase and related hemodynamic measures on post-transplant outcomes and heart utilization in donation after circulatory death (DCD) heart transplantation.

METHODS

United Network for Organ Sharing registry was queried to analyze adult recipients who underwent isolated DCD heart transplantation between January 1, 2019 and September 30, 2023. The recipients were stratified into 2 groups based on donor agonal period: <30 and ≥30 minutes. The primary outcome was 90-day post-transplant survival. Propensity score-matching was performed. Sub-analysis was performed to evaluate the association of agonal period with donor heart utilization. Additionally, the associations between different hemodynamic thresholds used to indicate onset of warm ischemia during the agonal phase with 90-day mortality were compared.

RESULTS

Eight hundred and eighty nine recipients were included, with 179 (20.1%) receiving hearts from donors with an agonal period of ≥30 minutes. Ninety-day survival (88.1% vs. 95.6%, p < 0.001) was significantly lower among the recipients of donors with an agonal period of ≥30 minutes. The lower 90-day survival persisted in a propensity score-matched comparison. Furthermore, longer agonal periods were associated with reduced donor heart utilization. Lastly, a time interval from a systolic blood pressure of 80 ± 5mmHg to death exhibited significantly higher association with 90-day mortality than a time interval from a systemic oxygen saturation 80 ± 5% to death.

CONCLUSIONS

Utilizing DCD donor hearts with agonal periods ≥30 minutes is associated with reduced post-transplant survival and decreased donor heart utilization. When assessing the onset of warm ischemia during the agonal phase, hypotension may serve as a more accurate indicator of myocardial ischemia and provide improved post-transplant prognostic insight than hypoxia.

Survival after heart transplants from circulatory-dead versus brain-dead donors: Meta-analysis of reconstructed time-to-event data

BACKGROUND

Heart transplantation (HTx) using donors after circulatory death (DCD) has the potential to significantly boost overall transplant rates. This study aims to reconstruct data from individual studies comparing survival between HTx from DCD recipients and donation after brain (DBD) recipients.

METHODS

MEDLINE, Embase, Scopus, were searched up to August 2024. We included studies that reported a Kaplan-Meier summary of survival comparing DCD and DBD HTx. Digitization of the Kaplan-Meier curves and reconstruction of individual patient data followed by survival analysis that was conducted using R software.

RESULTS

Six studies including a total of 3240 patients (2242 DBD and 998 DCD) were included in the final analysis. There was no significant difference in the overall survival rates between DCD and DBD patients (Hazard Ratio (HR): 1.01, 95 % CI [0.81-1.25], P = 0.91). However, the proportional hazard assumption was violated, deeming such results inconclusive. Time-varying flexible parametric model revealed a significantly declining survival in DCD recipients 3 years after surgery. Landmark analyses further suggest this declining trend in the DCD group at the two-year landmark (HR: 1.67, p = 0.021) and the four-year mark (HR: 2.78, p = 0.002). However, data beyond 6 years is limited. Evidence comparing direct procurement and normothermic regional perfusion is scarce, with no significant survival differences observed.

CONCLUSION

This meta-analysis shows that, despite similar early survival outcomes, DCD heart transplants showed a trend towards a lower long-term survival, with the difference becoming evident around three years post-transplantation. These findings highlight the need for enhanced monitoring and optimized post-transplant care in DCD recipients. Further studies with strict and long-term follow-up are warranted to confirm these results.

Impact of cardiopulmonary resuscitation on donation after circulatory death heart transplantation: A United Network for Organ Sharing registry analysis

BACKGROUND

The criteria for evaluating donations after circulatory death (DCD) heart allografts, particularly donor cardiopulmonary resuscitation (CPR) status, remains underexplored. This study evaluates the impact of donor CPR on post-transplant outcomes in DCD heart transplants.

METHODS

The UNOS registry was queried to analyze adult recipients who underwent DCD heart transplantation between 1/1/2019 and 3/31/2023, with a 1-year follow-up period extending to 3/31/2024. Primary outcomes were 90-day and 1-year post-transplant survival. 1:1 propensity score-matching was performed. Restricted cubic spline was used to model duration of CPR and likelihood of 1-year post-transplant mortality. Sub-analysis was performed to evaluate the effects of CPR duration on donor heart utilization.

RESULTS

A total of 683 DCD recipients were included, and 378 recipients (55.3%) received hearts from donors that underwent CPR. Recipients with donors who received CPR had similar 1-year (92.1% vs 90.7%) post-transplant survival compared to recipients with donors who did not receive CPR. The comparable post-transplant survival persisted in a propensity score-matched comparison. The spline model demonstrated that longer duration of CPR was not associated with lower odds of 1-year post-transplant survival compared to the reference of 15 minutes. In the sub-analysis, longer CPR duration was not significantly associated with reduced donor heart utilization.

CONCLUSIONS

Donors that received CPR requires consideration for DCD transplants since damage during cardiac arrest prior to withdrawal of life support may amplify warm ischemic injury during procurement. This study suggests that the use of DCD hearts that underwent CPR can expand the donor pool without compromising early post-transplant survival.

Extended Duration of Impella 5.5 Support Does Not Adversely Impact Outcomes Following Heart Transplantation: A National Registry Analysis

Prior studies assessing the effects of Impella 5.5 support duration on posttransplant outcomes have been limited to single-center case reports and series. This study evaluates the impact of Impella 5.5 support duration on outcomes following heart transplantation using the United Network for Organ Sharing database. Adult heart transplant recipients who were directly bridged to primary isolated heart transplantation with Impella 5.5 were included. The cohort was stratified into two groups based on the duration of Impella support: less than or equal to 14 and greater than 14 days. The primary outcome was 90 day posttransplant survival. Propensity score matching was performed. Sub-analysis was conducted to evaluate the impact of greater than 30 days of Impella support on 90 day survival. Three hundred thirty-two recipients were analyzed. Of these, 212 recipients (63.9%) were directly bridged to heart transplantation with an Impella support duration of greater than 14 days. The two groups had comparable 90 day posttransplant survival and complication rates. The comparable posttransplant survival persisted in a propensity score-matched comparison. In the sub-analysis, Impella support duration of greater than or equal to 30 days did not adversely impact 90 day survival. This study demonstrates that extended duration of support with Impella 5.5 as a bridge to transplantation does not adversely impact posttransplant outcomes. Impella 5.5 is a safe and effective bridging modality to heart transplantation.

Comparing Mid-Term Outcomes of Donation After Brain Death and Donation After Circulatory Death Orthotopic Heart Transplant Recipients-A Single-Center Retrospective UK Study

INTRODUCTION

The number of patients on heart transplant waitlists is growing globally, with an insufficient number of organ offers to meet this growing demand. To help improve patient outcomes, in the United Kingdom (UK), orthotopic cardiac transplantation (OCTx) can occur using hearts donated following donor brain death (DBD) or donor circulatory death (DCD). The aim of this paper was to compare outcomes between groups of DBD and DCD OCTx patients at Harefield Hospital.

METHODS

44 DCD patients (transplanted between 2012 and 2023) were matched (with outcomes blinded, by age and gender) with 33 DBD patients (transplanted between 2015 and 2023). Short-term outcomes (up until 1-year posttransplants, including outcomes such as primary graft dysfunction [PGD] and length of intensive care unit [ICU] stay) and midterm outcomes (up until 5 years posttransplant, including outcomes such as all-cause-mortality, episodes of rejection and graft left ventricular function) were assessed.

RESULTS

Overall, no significant differences were noted with regard to baseline characteristics, and outcome measures (both short and mid-term outcomes) between the matched DCD and DBD cohorts. Event-free survival with regard to all-cause mortality also remained not significantly different between both groups (log-rank p < 0.756).

CONCLUSION

In conclusion, our single-center UK data did not demonstrate any differences in outcomes between DCD and DBD OCTx patients. We add to growing literature that would support DCD organ use in heart transplantation, in an effort to reduce growing organ demand worldwide.

Durable left ventricular assist device in donation after circulatory death heart transplantation

BACKGROUND

This study evaluates outcomes following donation after circulatory death (DCD) heart transplantation in recipients with a durable left ventricular assist device (LVAD).

METHODS

The UNOS registry was queried to analyze adult recipients of isolated DCD heart transplantation between 1/1/2019-3/31/2023. The recipients were stratified by durable LVAD use as a bridge to transplantation. The primary outcome was 1-year post-transplant survival. Sub-group analyses were conducted to evaluate the effects of transplant status, device type, and donor type on 1-year survival.

RESULTS

A total of 703 recipients were included, of which 219 (31.2%) recipients were bridged with a durable LVAD. The recipients of DCD hearts with durable LVADs had significantly lower 1-year post-transplant survival compared to those without durable LVADs (88.4% vs. 93.6%, p=0.017). Among the recipients bridged with durable LVADs, status 4 recipients had significantly improved 1-year survival compared to statuses 2 and 3 recipients, similar to those without durable LVADs. Furthermore, the recipients with HeartMate II and HeartMate 3 had improved survival compared to those with the HeartWare HVAD, similar to those without durable LVADs. Lastly, the DCD and DBD recipients with durable LVADs had comparable 1-year survival (88.4% vs. 89.0%, p=0.763).

CONCLUSIONS

Recipients of DCD hearts bridged to transplantation with a durable LVAD exhibit reduced early post-transplant survival compared to those without a durable LVAD. However, clinical acuity and device type significantly influence post-transplant outcomes in this vulnerable population. Despite this, candidates with a durable LVAD can safely undergo DCD heart transplantation, achieving early post-transplant survival comparable to those of DBD heart transplantation.

Can we safely expand the donation after circulatory death donor heart pool by extending the donor age limit?

OBJECTIVE

This study evaluates the impact of donor age on outcomes following donation after circulatory death heart transplantation.

METHODS

The United Network for Organ Sharing registry was queried to analyze adult recipients who underwent isolated donation after circulatory heart transplantation from January 1, 2019, to September 30, 2023. The cohort was stratified into 2 groups according to donor age, where advanced donor age was defined as 40 years or more. Outcomes were 90-day and 1-year post-transplant survival. Propensity score matching was performed. Subgroup analysis was performed to evaluate the effects of recipient age on 90-day survival among the recipients with advanced-age donors.

RESULTS

A total of 994 recipients were included in the study period, and 161 patients (17.1%) received allografts from advanced-age donors. During the study period, the annual incidence of donation after circulatory heart transplantation with advanced-age donors substantially increased. The recipients with advanced-age donors had similar 90-day and 1-year post-transplant survivals compared with the recipients with younger donors. The comparable 90-day survival persisted in a propensity score-matched comparison. In the subgroup analysis among the recipients with advanced-age donors, the recipients aged 60 years or more had significantly reduced 90-day survival compared with the recipients aged less than 60 years.

CONCLUSIONS

The use of appropriately selected donation after circulatory donors aged 40 years or more has similar survival compared with that of younger donors. With careful candidate risk stratification and selection, consideration of using donation after circulatory donors aged more than 40 years may further ameliorate ongoing organ shortage with comparable early post-transplant outcomes.

The Rapidly Evolving Landscape of DCD Heart Transplantation

PURPOSE OF REVIEW

To summarise current international clinical outcomes from donation after circulatory death heart transplantation (DCD-HT); discuss procurement strategies, their impact on outcomes and overall organ procurement; and identify novel approaches and future areas for research in DCD-HT.

RECENT FINDINGS

Globally, DCD-HT survival outcomes (regardless of procurement strategy) are comparable to heart transplantation from brain dead donors (BDD). Experience with normothermic machine perfusion sees improvement in rates of primary graft dysfunction. Techniques have evolved to reduce cold ischaemic exposure to directly procured DCD hearts, though controlled periods of cold ischaemia can likely be tolerated. There is interest in hypothermic machine perfusion (HMP) for directly procured DCD hearts, with promising early results. Survival outcomes are firmly established to be equivalent between BDD and DCD-HT. Procurement strategy (direct procurement vs. regional perfusion) remains a source of debate. Methods to improve allograft warm ischaemic tolerance are of interest and will be key to the uptake of HMP for directly procured DCD hearts.

Direct procurement with machine perfusion and normothermic regional perfusion in donation after circulatory death heart transplantation

BACKGROUND

Donation after circulatory death (DCD) heart transplants have increased in the United States with direct procurement with machine perfusion (DPP) and thoracoabdominal normothermic regional perfusion (TA-NRP) techniques. There remains a paucity of data examining DPP and TA-NRP outcomes. The purpose of this study was to investigate the impact of the DCD technique on post-transplant outcomes compared to donation after brain death (DBD) donors.

METHODS

Adult patients undergoing heart transplantation between December 1, 2019, and June 30, 2023, were identified in the United Network for Organ Sharing registry. DPP and TA-NRP groups were identified using time of death to an aortic cross-clamp time of 30 minutes. Categorical variables were compared using the χ2 or Fisher exact test, and continuous variables were compared using the Mann-Whitney U test. Propensity score matching was performed using a 1:3 match. One-year survival was analyzed using the log-rank test and a Cox proportional hazard regression model.

RESULTS

During the study period, there were 7338 DBD and 419 DCD heart transplants. At 1 year post-transplant, there was no difference in survival between unmatched (P = .13) and matched (P = .36) DBD and DCD heart recipients. There was an increase in acute rejection and rejection requiring treatment in DCD recipients compared to DBD recipients in the matched cohort. A total of 134 TA-NRP transplants and 242 DPP transplants were performed. One-year survival and post-transplant outcomes were similar in the DPP and TA-NRP groups. TA-NRP functional warm ischemia time (fWIT) was increased significantly during the study period.

CONCLUSIONS

In this matched cohort, DCD heart recipients experienced increased acute rejection, both treated and nontreated, compared to DBD heart recipients. Despite differences in the techniques and likely in fWIT, acute rejection, survival, and other secondary outcomes are similar with DPP and TA-NRP.

Procurement Trends, Indications, and Outcomes of Heart-Lung Transplantation in the Contemporary Era

BACKGROUND

Evolving trends in organ procurement and technological innovation prompted an investigation into recent trends, indications, and outcomes following combined heart-lung transplantation (HLTx).

METHODS

The United Network for Organ Sharing database was queried for all adult (≥18 years) HLTx performed between July 1, 2013 and June 30, 2023. Patients with previous transplants were excluded. The primary endpoint was the effect of donor, recipient, and transplantation characteristics on 1- and 5-year survival. Secondary analyses included a comparison of HLTx at high- and low-volume centers, an assessment of HLTx following donation after circulatory death (DCD), and an evaluation of HLTx volume over time. Cox proportional-hazards models were used to assess factors associated with mortality. Temporal trends were evaluated with linear regression.

RESULTS

After exclusions, 319 patients were analyzed, of whom 5 (1.6%) were DCD. HLTx volume increased from 2013 to 2023 (p < 0.001). One- and 5-year survival following HLTx was 84.0% and 59.5%, respectively. One-year survival was higher for patients undergoing HLTx at a high-volume center (88.3% vs. 77.9%; p = 0.012). After risk adjustment, extracorporeal membrane oxygenation support 72 h posttransplant and predischarge dialysis were associated with increased 1-year mortality (HR = 3.19, 95% CI = 1.86-5.49 and HR = 3.47, 95% CI = 2.17-5.54, respectively) and 5-year mortality (HR = 2.901, 95% CI = 1.679-5.011 and HR = 3.327, 95% CI = 2.085-5.311, respectively), but HLTx at a high-volume center was not associated with either.

CONCLUSIONS

HLTx volume has resurged, with DCD HLTx emerging as a viable procurement strategy. Factors associated with 1- and 5-year survival may be used to guide postoperative management following HLTx.

Outcomes of Heart Transplantation From Donation After Circulatory Death: An Up-to-date Systematic Meta-analysis

BACKGROUND

Donation after circulatory death (DCD) heart transplantation (HTx) significantly expands the donor pool and reduces waitlist mortality. However, high-level evidence-based data on its safety and effectiveness are lacking. This meta-analysis aimed to compare the outcomes between DCD and donation after brain death (DBD) HTxs.

METHODS

Databases, including MEDLINE, Embase, CINAHL, and the Cochrane Central Register of Controlled Trials, were systematically searched for randomized controlled trials and observational studies reporting the outcomes of DCD and DBD HTxs published from 2014 onward. The data were pooled using random-effects models. Risk ratios (RRs) with 95% confidence intervals (CIs) were used as the summary measures for categorical outcomes and mean differences were used for continuous outcomes.

RESULTS

Twelve eligible studies were included in the meta-analysis. DCD HTx was associated with lower 1-y mortality rate (DCD 8.13% versus DBD 10.24%; RR = 0.75; 95% CI, 0.59-0.96; P  = 0.02) and 5-y mortality rate (DCD 14.61% versus DBD 20.57%; RR = 0.72; 95% CI, 0.54-0.97; P  = 0.03) compared with DBD HTx.

CONCLUSIONS

Using the current DCD criteria, HTx emerges as a promising alternative to DBD transplantation. The safety and feasibility of DCD hearts deserve further exploration and investigation.

Expanding Horizons in Cardiac Transplant: Efficacy and Outcomes of Circulatory and Brain Death Donor Hearts in a Newly Implemented Cardiac Transplant Program with Limited Donor Accessibility and a Literature Review

(1) Background: Cardiac donation after circulatory death (DCD) is an emerging paradigm in organ transplantation. However, this technique is recent and has only been implemented by highly experienced centers. This study compares the characteristics and outcomes of thoraco-abdominal normothermic regional perfusion (TANRP) and static cold-storage DCD and traditional donation after brain death (DBD) cardiac transplants (CT) in a newly stablished transplant program with restricted donor availability. (2) Method: We performed a retrospective, single-center study of all adult patients who underwent a CT between November 2019 and December 2023, with a follow-up conducted until August 2024. Data were retrieved from medical records. A review of the current literature on DCD CT was conducted to provide a broader context for our findings. The primary outcome was survival at 6 months after transplantation. (3) Results: During the study period, 76 adults (median age 56 years [IQR: 50-63 years]) underwent CT, and 12 (16%) were DCD donors. DCD donors had a similar age (46 vs. 47 years, p = 0.727), were mostly male (92%), and one patient had left ventricular dysfunction during the intraoperative DCD process. There were no significant differences in recipients' characteristics. Survival was similar in the DCD group compared to DBD at 6 months (100 vs. 94%) and 12 months post-CT survival (92% vs. 94%), p = 0.82. There was no primary graft dysfunction in the DCD group (9% in DBD, p = 0.581). The median total hospital stay was longer in the DCD group (46 vs. 21 days, p = 0.021). An increase of 150% in transplantation activity due to DCD was estimated. (4) Conclusions: In a new CT program that utilized older donors and included recipients with similar illnesses and comorbidities, comparable outcomes between DCD and DBD hearts were observed. DCD was rapidly incorporated into the transplant activity, demonstrating an expedited learning curve and significantly increasing the availability of donor hearts.