OBJECTIVE:The United States' experience with heart transplantation following donation after circulatory death (DCD HT) has expanded since clinical adoption in 2019. We aimed to examine a large institution's outcomes associated with DCD HT versus HT following donation after brain death (DBD). METHODS:Adult heart recipients and corresponding donors at a single quaternary academic center from January 2019 to October 2024 were included. Recipient and donor data were extracted from the institution's electronic medical record and the United Network for Organ Sharing registry, respectively. The primary outcome was overall survival. RESULTS:In total, 553 heart donors and recipients met inclusion criteria, including 404 (73%) DBD and 149 (27%) DCD recipients. Recipients of DCD allografts were less likely to have an intra-aortic balloon pump before transplant, but there was no significant difference in waitlist status at the time of transplant between the 2 groups. DCD allografts had increased total ischemic time (defined by United Network for Organ Sharing registry as time between donor explant and re-perfusion in the recipient) (5.7 vs 3.7 hours; P < .001) and distance to travel (381 vs 299 miles; P = .001) compared with DBD allografts. Unadjusted Kaplan-Meier survival analysis demonstrated no significant difference between DCD and DBD recipients' cumulative survival (log-rank P = .14). The rate of severe primary graft dysfunction was not significantly different between groups (12% DCD vs 11% DBD; P = .65). CONCLUSIONS:Cardiac allografts from DCD donors perform similarly to a contemporary population of DBD allografts. The rate of severe primary graft dysfunction and the unadjusted cumulative survival were not significantly different between DCD and DBD cohorts.

Organ allocation guidelines prioritize patients at risk of waitlist mortality. In the United States, both the heart and lung allocation systems were revised within the last ten years. There is no specific allocation system for patients listed for combined heart-lung transplant. With updates to the heart and lung allocation systems, we have observed that combined heart-lung transplant patients can face unnecessarily long wait times. A focused listing pathway to better prioritize potential combined heart-lung transplant recipients could help ensure the appropriate patients are transplanted effectively and efficiently.

Abstract Background Surgical site infections (SSI) complicate 4.8-12.4% of orthotopic heart transplants (OHT) and result in increased length of hospital stay, mortality, and health care costs. As such, the need for accurate SSI surveillance systems for OHT is critical. This study aimed to evaluate the diagnostic accuracy of the National Healthcare Safety Network (NHSN) and Society of Thoracic Surgeons (STS) surveillance systems for SSI against the gold standard of a detailed manual adjudication process performed by Transplant ID physicians (TXID). Methods We retrospectively reviewed single-organ OHT performed at an academic medical center between 1/1/19 and 12/31/20 among adult patients (≥18 years). Each OHT was adjudicated for SSI by NHSN, STS, and TXID SSI definitions. The TXID definition was the same as the NHSN classification. The surveillance window was 90 days for NHSN and TXID. STS adopted a 90-day surveillance window for deep sternal wound infections from 7/1/20 onward. Results TXID identified 17 (10.5%) SSI among 162 OHT surgeries during the study period. NHSN identified only 7 (4.3%) SSI, including 3 false positive SSI, which were not considered SSI by TXID. STS identified only 4 (2.5%) SSI during the study period and no false positive SSI(Fig 1). The sensitivity, specificity, positive-predicted-value, and negative-predicted-value for NHSN were 23.5%, 97.9%, 57.1%, and 91.6% and for STS 23.5%, 100%, 100%, and 91.8%, respectively. The suboptimal sensitivity of NHSN was mostly explained by intervening surgeries (such as chest closures or washouts) that prevented a subsequent SSI from being attributed to the OHT, and by STS’s prior 30-day surveillance window. Conclusion Accuracy of SSI surveillance is essential for SSI prevention. Current SSI surveillance systems have low sensitivity in detecting OHT SSI, which is likely due to the complex nature of the hospital courses following OHT surgeries. While a manual adjudication performed by Transplant ID physicians is time- and resource-intensive, it likely provides a more accurate depiction of SSI rates compared to automated surveillance systems. Future studies are needed to determine how NHSN and STS surveillance systems can be adjusted to more accurately identify OHT SSI. Disclosures Jessica Seidelman, MD, MPH, 3M: Expert Testimony Becky A. Smith, MD, UpToDate: royalties Jacob Schroder, MD, Abbott: Advisor/Consultant|Abiomed: Advisor/Consultant Barbara D. Alexander, MD, Basilea: Advisor/Consultant|F2G: Advisor/Consultant|F2G: Grant/Research Support|HealthTrackRx: Advisor/Consultant|HealthTrackRx: Board Member|Scynexis: Grant/Research Support|TFF Pharmaceuticals: Advisor/Consultant

Surgical site infections (SSI) surveillance after heart transplantation is critical for preventing SSI. We analyzed the accuracy of 3 SSI surveillance systems: National-Healthcare-Safety-Network (NHSN), Society-of-Thoracic-Surgeons (STS), and detailed manual surveillance (TXID). National-Healthcare-Safety-Network and Society-of-Thoracic-Surgeons showed low sensitivity compared to TXID, highlighting the need for more accurate and efficient surveillance strategies.

BACKGROUND:Tricuspid regurgitation (TR) is common immediately after orthotopic heart transplantation (OHT), though the expected outcomes of TR over time remain undefined. In this study, we examined the natural trajectory of TR in the first 120 days post-transplantation. We observed the clinical phenotypes of trajectories of TR after OHT, and assessed trajectory correlation with 1-year mortality and degree of right ventricular (RV) dysfunction. METHODS:All patients who underwent OHT at a single institution from January 2009 to July 2019 were included, unless death occurred during the index hospitalization. TR and RV dysfunction on follow-up transthoracic echocardiograms were tracked on 4-point scales and latent-class mixed modeling (LCMM) identified classes of TR trajectories. Fisher's exact test was used to compare 1-year mortalities between classes. RESULTS:Based on LCMM, four distinct classes of TR trajectories emerged, characterized as sustained (n = 40), variable (n = 172), stable (n = 175), and recovered (n = 189) TR. Significant differences in mortality rates were found amongst classes at 10.0%, 8.1%, 4.0%, and 2.6%, respectively (p = 0.025). The degree of RV dysfunction mirrored TR severity in all subsets except the sustained TR group. CONCLUSIONS:The trajectory of TR in the first 120 days post-OHT is associated with 1-year mortality. In many subsets, there is a close association with TR grade and RV function improvement. However, in the sustained TR group, RV function improved without subsequent improvement in TR severity. These findings could identify patients with higher mortality risk for whom more frequent follow-up or intervention is warranted.

BACKGROUND:Multiple advanced preservation technologies are now available and have demonstrated utility in organ assessment and preservation. The Paragonix SherpaPak Cardiac Transport System (SCTS) has become the most common method of static preservation, demonstrating superior outcomes to historic ice storage. To date, no preservation method has reported improved post-transplant survival. METHODS:Data from the GUARDIAN-Heart Registry, the largest real-world registry focused on organ preservation, were analyzed to quantify post-transplant clinical outcomes and survival in transplant cases utilizing ice cooler storage or moderate hypothermic preservation using SCTS. The independent contributions of the organ preservation method on outcomes, including severe primary graft dysfunction (PGD), right ventricular dysfunction (RVD), and mortality, were analyzed using propensity matching and logistic regression. RESULTS:Among 1,261 US adult heart transplants performed between October 2015 and January 2024, SCTS utilization was associated with significant reductions in incidence of severe PGD (Ice 10.8% vs SCTS 6.8%, p = 0.015) and severe RVD (Ice 9.9% vs SCTS 6.1%, p = 0.022). SCTS use was identified as an independent predictor of severe PGD (Odds Ratio = 0.60, p = 0.012) and severe RVD (OR = 0.75, p = 0.047). In the propensity-matched cohort, SCTS utilization was associated with a significant reduction in mortality after 2 years (Ice 10.5% vs. SCTS 5.7%, p = 0.042), and the Kaplan-Meier survival probability over 2 years was significantly higher in the SCTS cohort (p = 0.022). CONCLUSIONS:Moderate, controlled hypothermic preservation using SCTS significantly improves post-transplant outcomes and 2-year survival. This is the first study of any advanced heart preservation modality to demonstrate a significant impact on transplant survival.

BACKGROUND:We previously reported that concurrent tricuspid valve surgery (TVS) was not associated with a lower incidence of early right heart failure (RHF) in patients undergoing durable left ventricular assist device (LVAD) implantation. This follow-up analysis aimed to further define the clinical impact of concurrent TVS after 2 months of follow-up. METHODS:Patients with moderate or severe tricuspid regurgitation (TR) on preoperative echocardiography (n = 71) were randomized to LVAD implantation either alone (no TVS group; n = 34) or with concurrent TVS (TVS group; n = 37). Randomization was stratified by preoperative right ventricular dysfunction. The patients were followed for at least 12 months after surgery. The incidence of RHF was determined by an adjudication committee using Interagency Registry for Mechanically Assisted Circulatory Support criteria. Functional studies and repeat echocardiography were performed at 12 months. RESULTS:Demographics were similar in the 2 study arms. At 12 months, the rate of moderate or severe RHF was 50.0% in the no TVS arm versus 51.4% in the TVS arm. No patients developed RHF between 6 and 12 months following the procedure. Death from RHF was 5.4% in the TVS arm versus 8.8% in the no TVS arm. At 12 months, there was no significant difference in TR severity between the 2 arms, owing to improvement in TR severity in the no TVS arm. Cardiopulmonary exercise testing at 12+ months revealed no significant between-group difference in peak oxygen consumption. CONCLUSIONS:In patients with significant preimplantation TR, the severity of TR improved over time in the no TVS arm with LVAD implantation alone. By 12 months, there was no significant difference in TR severity between the 2 arms. This may account for the lack of difference in late clinical or functional parameters.

In the Ross procedure, homograft stenosis and regurgitation have limited the longevity of the right ventricle-to-pulmonary artery (RV-PA) conduit. Partial heart transplantation (PHT) facilitates conduit growth throughout the life of the child. We report the application of PHT of the RV-PA conduit during a Ross procedure, "living Ross," in a 3-year old patient with a congenital unicuspid aortic valve. Pulmonary autograft was used in the aortic position, and an aortic root allograft from the cardiectomy of an adult heart transplant recipient served as the RV-PA conduit. We hypothesize that this Ross procedure, the living Ross, improves the longevity of the RV-PA conduit.

We present an approach to constructing a practical coarsening algorithm and interpolation operator for the algebraic multigrid (AMG) method, tailored towards systems of partial differential equations (PDEs) with large near-kernels, such as H(curl) and H(div). Our method builds on compatible relaxation (CR) and the ideal interpolation model within the generalized AMG (GAMG) framework but introduces several modifications to define an AMG method for PDE systems. We construct an interpolation operator through a coarsening process that first coarsens a nodal dual problem and then builds the coarse and fine variables using a matching algorithm. Our interpolation follows the ideal formulation; however, we enhance the sparsity of ideal interpolation by decoupling the fine and coarse variables completely. When the coarse variables align with the geometric refinement, our method reproduces re-discretization on unstructured meshes. Together with an automatic smoother construction scheme that identifies the local near kernels, our approach forms a complete two-grid method. Finally, we also show numerical results that demonstrate the effectiveness of this interpolation scheme by applying it to targeted problems and the Stokes system.

OBJECTIVE:Orthotopic heart transplant is the definitive option for pediatric patients with end-stage heart failure. Unfortunately, the greatest contributor to waitlist mortality has been a shortage of available hearts for transplant. Donation after circulatory death with normothermic regional perfusion may mitigate this supply-demand mismatch. METHODS:Donation after circulatory death with normothermic regional perfusion recipients were matched to similar donation after brain death recipients. Primary end points included 1-year survival and episodes of primary graft dysfunction at 1 year. Secondary end points included treated rejection at 1 year and ventricular systolic and diastolic function on echocardiogram at time of discharge. Elevated filling pressures or decreased cardiac output were also examined via cardiac catheterization data at time of endomyocardial biopsy at 1 year. RESULTS:Twelve donation after circulatory death procurements were attempted and 9 hearts procured. Donor cardiac arrest and cardiac function before procurement were similar in both groups. Donation after brain death recipients spent more time on the waitlist. After transplant, biventricular function was similar in both groups at time of discharge and at 1-year follow-up. There were no differences between groups with regard to primary graft dysfunction or instances of treated rejection at 1 year. CONCLUSIONS:This study represents the largest single-institution cohort of pediatric recipients of hearts obtained after donation after circulatory death with normothermic regional perfusion compared with demographically similar donation after brain death cardiac transplant recipients. These results are indicative of equivalent outcomes at 1-year, suggesting that donation after circulatory death with normothermic regional perfusion is a viable method to expand the pediatric cardiac donor pool.

Outflow graft obstruction (OGO) is an under-reported but severe complication after insertion of magnetically levitated centrifugal-flow left ventricular assist devices (LVADs). The optimal treatment and long-term outcomes have not been well-described. We report a retrospective single high-volume center's experience with surgical exploration for OGO from June 2019 to October 2023. Outflow graft obstruction was identified in 19 LVAD recipients from a total experience of 550 LVAD implants (3.3%). Median time of LVAD support to development of OGO was 32.5 months (interquartile range [IQR], 28-47.5). Low-flow alarms were the most common presentation, followed by dyspnea on exertion, and syncope. Computed tomography angiography (CTA) and echocardiography were the most common diagnostic modalities. Aortic valve opening with every beat and worsened mitral insufficiency were both more common at presentation compared to prior echocardiographic studies. Surgical excision of the bend relief (BR) and evacuation of proteinaceous material between the BR and the outflow graft immediately improved hemodynamics and LVAD function. There were no in-hospital mortalities, and all patients were discharged home after a median length of stay of 9 days (IQR, 10-21). All but four patients were alive at median follow-up 21 months. Thirteen of the 19 patients were readmitted a total of 50 times, none for recurrent OGO.

Despite improvements in managing earlier stage heart disease, the population of patients needing heart transplants continues to increase in the United States. Fortunately, novel methods of procuring and preserving donor hearts, including the use of ex-vivo heart perfusion and controlled hypothermic preservation, have enabled a rise in heart transplantation. In particular, ex-vivo heart perfusion has contributed to increased utilization of donation after circulatory death (DCD), as well as enhanced use of donor hearts from increased geographic distances and extended criteria (marginal) donors. The use of such preservation technologies, however, has coincided with a significant increase in the cost of donor heart procurement and the advent of a donor organ procurement services industry. We aim to provide an overview on the rising costs of heart donation, explore the causes of such increase, and discuss potential solutions to drive both cost savings and increased access to heart transplantation.

BACKGROUND:Out-of-sequence (OOS) allocation is a mechanism by which donor organs are offered outside the standard match run, typically to expedite the placement of hard-to-match or time-sensitive allografts. Rising OOS rates are described in abdominal organ transplantation, but limited data exist regarding OOS practices in heart transplantation. METHODS:The United Network for Organ Sharing (UNOS) was used to identify all adult heart transplant recipients and corresponding donors between January 2015 and March 2024. The Potential Transplant Recipient file was then used to classify each donation as either in-sequence or out-of-sequence. We assessed temporal trends and practice patterns in relation to OOS allocation. Additionally, we evaluated donor and recipient characteristics and post-transplant survival outcomes. RESULTS:Within the study period, there were 25,608 heart transplantations, of which 509 (2%) were from OOS donors. OOS allocation increased 2-fold over the study period (1.4%-3.1%). Use varied across Organ Procurement Organizations (OPOs) (0-5.4%) and transplant centers (0-16.7%), with a small subset of OPOs accounting for the majority of OOS allocations. Recipients of OOS-allocated allografts were more likely to be nonhospitalized older females with type O blood group. There was no significant difference in overall survival rates between OOS and in-sequence recipients at 1 year (93.1% vs 91.6%, respectively). CONCLUSIONS:OOS heart allocation, while rare, is increasing, and varies by geography and OPO. The OOS mechanism may provide an opportunity to improve organ recovery and support transplant access for harder-to-match candidates. However, standardization of OOS practices is needed to ensure equity in transplant access.

BACKGROUND:A preservation system, the Organ Care System (OCS; TransMedics) uses normothermic pulsatile perfusion during organ transport for heart transplantation. This system has demonstrated favorable outcomes in hearts recovered from extended-criteria donors after brain death (DBD) and donors after circulatory death (DCD). METHODS:The OCS Heart Perfusion Registry collects data on US heart transplantations using the OCS, static cold storage (SCS), or thoracoabdominal normothermic regional perfusion (NRP) and donor hearts recovered from DBD or DCD donors. We analyzed donor and recipient characteristics and posttransplantation outcomes in patients transplanted with OCS donor hearts (either DBD or DCD) compared with SCS hearts, and with OCS hearts from DCD donors compared with those recovered with NRP followed by SCS. Propensity score matching was used in survival analyses to adjust for differences among recipient characteristics. RESULTS:Between 2021 and 2023, 3225 consecutive heart transplantations enrolled from 56 centers were analyzed in the Heart Perfusion Registry. The OCS was used in 854 of 3225 heart transplantations (26.4%), among which 340 (39.8%) were DBD and 514 (60.2%) were DCD donors, whereas 2174 DBD donors were recovered with SCS and another 197 DCD donors with NRP techniques. The OCS-DBD group experienced a greater number of organ offer refusals before final acceptance (13 versus 6; Wilcoxon rank sum, P<0.001) and a longer transport distance (667 miles versus 232 miles; Wilcoxon rank sum, P<0.001) compared with SCS-DBD. Survival at 12 months was similar between the 2 groups (89.9% for OCS-DBD versus 90.6% for SCS-DBD; marginal Cox model, P=0.54). Among the OCS-DCD and SCS-DBD groups, survival at 12 months was also similar (91.0% versus 92.5%, respectively; marginal Cox model, P=0.32). The OCS-DCD and NRP-DCD groups demonstrated similar survival (91.0% versus 91.7%, respectively; log rank, P=0.63), although the transport distance was longer in OCS-DCD compared with DCD with NRP followed by SCS (400 miles versus 223 miles; Wilcoxon rank sum, P<0.001). By 2023, 90% of all OCS donor management and recovery was performed with dedicated organ recovery teams. CONCLUSIONS:We demonstrate that real-world implementation of the OCS for DBD donors (using predominantly a dedicated recovery team) is associated with expanded donor criteria, longer transport distance, and excellent posttransplantation outcomes. In OCS-DCD donors, outcomes parallel those of donors recovered with NRP-DCD and compare favorably with DBD donor organs.

OBJECTIVE:To evaluate characteristics and outcomes of patients bridged to orthotopic heart transplantation with microaxial left ventricular assist device (ma-LVAD) versus durable LVAD (d-LVAD). METHODS:This was a single-center retrospective cohort study in which characteristics outcomes of patients undergoing orthotopic heart transplantation between May 2019 and May 2024 who were bridged with ma-LVAD versus d-LVAD, were compared. RESULTS:Over the study period, the percentage of patients bridged with ma-LVAD increased from 0% to 20%. Patients bridged with d-LVAD were more likely to have history of hypertension (80% vs 65%; P = .03), a higher body mass index (32.53 vs 28.15; P < .0001), and anti-human leukocyte antigens antibodies (54% vs 36%; P = .02) before transplant, otherwise groups were similar in their baseline characteristics. Unadjusted Kaplan-Meier analysis demonstrated no difference in survival between these 2 bridging strategies. However, postoperative blood product use (3 vs 0 units; P < .0001), moderate or severe primary graft dysfunction (27% vs 14%; P = .04), and delayed sternal closure (45% vs 9%; P < .0001) were all higher among those bridged with d-LVAD versus ma-LVAD. Rejection on the first postoperative biopsy was reported in a 60% in the d-LVAD group versus 33% in the ma-LVAD group (P = .0006). Postoperative intensive care unit (7 vs 6 days; P = .03) and overall postoperative length of stay (17 vs 12 days; P = .002) were greater in patients bridged with d-LVAD versus ma-LVAD, respectively. CONCLUSIONS:The use of ma-LVAD compared with d-LVAD as a bridging strategy was not associated with differences in survival. However, bridging with ma-LVAD compared with d-LVAD was associated with lower morbidity after orthotopic heart transplantation.