Implementation Science to Achieve Equity in Heart Failure Care: A Scientific Statement From the American Heart Association.

Guideline-directed medical therapies and guideline-directed nonpharmacological therapies improve quality of life and survival in patients with heart failure (HF), but eligible patients, particularly women and individuals from underrepresented racial and ethnic groups, are often not treated with these therapies. Implementation science uses evidence-based theories and frameworks to identify strategies that facilitate uptake of evidence to improve health. In this scientific statement, we provide an overview of implementation trials in HF, assess their use of conceptual frameworks and health equity principles, and provide pragmatic guidance for equity in HF. Overall, behavioral nudges, multidisciplinary care, and digital health strategies increased uptake of therapies in HF effectively but did not include equity goals. Few HF studies focused on achieving equity in HF by engaging stakeholders, quantifying barriers and facilitators to HF therapies, developing strategies for equity informed by theory or frameworks, evaluating implementation measures for equity, and titrating strategies for equity. Among these HF equity studies, feasibility was established in using various educational strategies to promote organizational change and equitable care. A couple include ongoing randomized controlled pragmatic trials for HF equity. There is great need for additional HF implementation trials designed to promote delivery of equitable guideline-directed therapy.

Subsequent kidney transplant after pediatric heart transplant: Prevalence and risk factors.

Pediatric heart failure and transplantation carry associated risks for kidney failure and potential need for kidney transplant following pediatric heart transplantation (KT/pHT). This retrospective, United Network of Organ Sharing study of 10,030 pediatric heart transplants (pHTs) from 1987 to 2020 aimed to determine the incidence of waitlisting for and completion of KT/pHT, risk factors for KT/pHT, and risk factors for nonreceipt of a KT/pHT. Among pHT recipients, 3.4% were waitlisted for KT/pHT (median time of 14 years after pHT). Among those waitlisted, 70% received a KT/pHT, and 18% died on the waitlist at a median time of 0.8 years from KT/pHT waitlisting (median age of 20 years). Moderate-high sensitization at KT/pHT waitlisting (calculated panel reactive antibody, ≥ 20%) was associated with a lower likelihood of KT/pHT (adjusted hazard ratio, 0.67; 95% confidence interval, 0.47-0.95). Waitlisting for heart transplantation simultaneously with kidney transplant (adjusted hazard ratio, 3.73; 95% confidence interval, 2.01-6.92) was associated with increased risk of death on the KT/pHT waitlist. While the prevalence of KT/pHT is low, there is substantial mortality among those waitlisted for KT/pHT. These findings suggest a need to consider novel risk factors for nonreceipt of KT/pHT and death on the waitlist in prioritizing criteria/guidelines for simultaneous heart-kidney transplantation.

Why partial heart transplantation could be regulated as organ transplantation.

Partial heart transplant (PHT) is a recent clinical innovation involving the transplantation of a segment of the heart (valves) directly from the deceased donor into the recipient patient. This procedure holds out the possibility of significant benefit, especially for pediatric patients because these grafts show growth potential after transplant, reducing or eliminating the current need for repeat procedures. The clinical process for donation and transplant of partial heart (PH) grafts generally follows an organ clinical pathway; however, the Food and Drug Administration has recently stated its intent to regulate PH as tissues, raising a host of regulatory considerations. PHT requires donor testing and eligibility determinations within a short, clinically viable timeframe and, similar to organ transplant, involves donor-recipient matching. Waitlist allocation policies that are a regulatory focus of the Organ Procurement and Transplantation Network including equity and efficiency may become relevant. Oversight of PHT by the Organ Procurement and Transplantation Network could be accomplished through interpretation of the vascular composite allograft definition or through designation by the US Department of Health and Human Services of PH grafts as organs. While some clinical questions remain unanswered, it is important to carefully address these regulatory considerations to support the emergence of this innovation and ensure the continued trust of the donating public and the patients who may benefit from PHT.

Status 2 upgrade indication impacts posttransplant mortality in patients bridged with intraaortic balloon pump in the new heart allocation system.

To evaluate outcomes of patients undergoing heart transplants (HTs) using an intra-aortic balloon pump (IABP) under exception status. Adult patients supported by an IABP who underwent HT between November 18, 2018, and December 31, 2020, as documented in the United Network for Organ Sharing, were included. Patients were stratified according to requests for exception status. Kaplan-Meier methodology was used to look for differences in survival between groups. A total of 1284 patients were included; 492 (38.3%) were transplanted with an IABP under exception status. Exception status patients had higher body mass index, were more likely to be Black, and had longer waitlist times. Exception status patients received organs from younger donors, had a shorter ischemic time, and had a higher frequency of sex mismatch. The 1-year posttransplant survival was 93% for the nonexception and 88% for the exception IABP patients (hazard ratio: 1.85 [95% confidence interval: 1.12-2.86, P = .006]). The most common reason for requesting an exception status was inability to meet blood pressure criteria for extension (37% of patients). The most common reason for an extension request for an exception status was right ventricular dysfunction (24%). IABP patients transplanted under exception status have an increased 1-year mortality rate posttransplant compared with those without exception status.

Redefining the molecular rejection states in 3230 heart transplant biopsies: Relationships to parenchymal injury and graft survival.

The first-generation Molecular Microscope (MMDx) system for heart transplant endomyocardial biopsies used expression of rejection-associated transcripts (RATs) to diagnose not only T cell-mediated rejection (TCMR) and antibody-mediated rejection (ABMR) but also acute injury. However, the ideal system should detect rejection without being influenced by injury, to permit analysis of the relationship between rejection and parenchymal injury. To achieve this, we developed a new rejection classification in an expanded cohort of 3230 biopsies: 1641 from INTERHEART (ClinicalTrials.gov NCT02670408), plus 1589 service biopsies added to improve the power of the machine learning algorithms. The new system used 6 rejection classifiers instead of RATs and generated 7 rejection archetypes: No rejection, 48%; Minor, 24%; TCMR1, 2.3%; TCMR2, 2.7%; TCMR/mixed, 2.7%; early-stage ABMR, 3.9%; and fully developed ABMR, 16%. Using rejection classifiers eliminated cross-reactions with acute injury, permitting separate assessment of rejection and injury. TCMR was associated with severe-recent injury and late atrophy-fibrosis and rarely had normal parenchyma. ABMR was better tolerated, seldom producing severe injury, but in later biopsies was often associated with atrophy-fibrosis, indicating long-term risk. Graft survival and left ventricular ejection fraction were reduced not only in hearts with TCMR but also in hearts with severe-recent injury and atrophy-fibrosis, even without rejection.

OPTN/SRTR 2022 Annual Data Report: Heart.

The number of heart transplants in the United States has continued to increase. Since 2011, pediatric heart transplants have increased 31.7% to 494 and adult heart transplants have increased 85.8% to 3,668 in 2022. The numbers of new candidates for pediatric and adult heart transplants have also increased, with 703 new pediatric candidates and 4,446 new adult candidates in 2022. Adult heart transplant rates continue to rise, peaking at 122.5 transplants per 100 patient-years in 2022; however, the pediatric heart transplant rate decreased to its lowest rate in the past decade, 104.2 transplants per 100 patient-years, a decrease of 13.9% from 121 transplants per 100 patient-years in 2011. Despite this, pretransplant mortality among pediatric candidates has decreased by 52.2%, from 20.8 deaths per 100 patient-years in 2011 to 10.0 deaths per 100 patient-years in 2022, but remains excessive for candidates younger than 1 year at 25.7 deaths per 100 patient-years. Among adult candidates, pretransplant mortality declined from 15 deaths per 100 patient-years in 2011 to 8.7 deaths per 100 patient-years in 2022. Since 2011, posttransplant mortality has been stable to slightly better; among recipients who underwent transplant in 2015-2017, the 1-, 3-, and 5-year pediatric survival rates were 93.7%, 89.2%, and 85.0%, respectively, and the adult survival rates were 91.3%, 85.7%, and 80.4%. Donor trends have been favorable, with an increase in the numbers of hearts recovered and growing numbers of hearts procured after circulatory death.

Longitudinal outcomes of COVID-19 in solid organ transplant recipients from 2020 to 2023.

Data regarding coronavirus disease 2019 (COVID-19) outcomes in solid organ transplant recipients (SOTr) across severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) waves, including the impact of different measures, are lacking. This cohort study, conducted from March 2020 to May 2023 in Toronto, Canada, aimed to analyze COVID-19 outcomes in 1975 SOTr across various SARS-CoV-2 waves and assess the impact of preventive and treatment measures. The primary outcome was severe COVID-19, defined as requiring supplemental oxygen, with secondary outcomes including hospitalization, length of stay, intensive care unit (ICU) admission, and 30-day and 1-year all-cause mortality. SARS-CoV-2 waves were categorized as Wildtype/Alpha/Delta (318 cases, 16.1%), Omicron BA.1 (268, 26.2%), Omicron BA.2 (268, 13.6%), Omicron BA.5 (561, 28.4%), Omicron BQ.1.1 (188, 9.5%), and Omicron XBB.1.5 (123, 6.2%). Severe COVID-19 rate was highest during the Wildtype/Alpha/Delta wave (44.6%), and lower in Omicron waves (5.7%-16.1%). Lung transplantation was associated with severe COVID-19 (OR: 4.62, 95% CI: 2.71-7.89), along with rituximab treatment (OR: 4.24, 95% CI: 1.04-17.3), long-term corticosteroid use (OR: 3.11, 95% CI: 1.46-6.62), older age (OR: 1.51, 95% CI: 1.30-1.76), chronic lung disease (OR: 2.11, 95% CI: 1.36-3.30), chronic kidney disease (OR: 2.18, 95% CI: 1.17-4.07), and diabetes (OR: 1.97, 95% CI: 1.37-2.83). Early treatment and ≥3 vaccine doses were associated with reduced severity (OR: 0.29, 95% CI: 0.19-0.46, and 0.35, 95% CI: 0.21-0.60, respectively). Tixagevimab/cilgavimab and bivalent boosters did not show a significant impact. The study concludes that COVID-19 severity decreased across different variants in SOTr. Lung transplantation was associated with worse outcomes and may benefit more from preventive and early therapeutic interventions.

Posttransplant atrial fibrillation: Evidence of early posttransplant recipient-to-donor atrioatrial connections.

INTRODUCTION: Atrial fibrillation and atrial flutter originating from the donor s heart is a commonly reported complication post heart transplant. Atrial tachyarrhythmia originating from the recipient s heart, propagated through recipient-to-donor connections, is rare with only few cases reported in the literature; most reported cases from our review occur years post-transplant. CASE: A 47-year-old male presented with atrial tachycardia 6 months post heart transplant. Electrophysiologic study demonstrated atrial fibrillation originating from native heart and propagated through atrio-atrial connections to the donor heart. This arrhythmia was successfully terminated with radiofrequency ablation. CONCLUSION: Atrio-atrial connection between recipient and donor can form as early as a few months post heart transplant. Radiofrequency ablation appears to be an effective treatment for atrial fibrillation propagated through donor-to-recipient connections.

Rates of Reproductive Counseling and Contraception Use in Patients with Heart Failure at a Tertiary Care Center.

BACKGROUND: Increasing numbers of women of childbearing age have cardiac disease, including heart failure (HF). In these women, pregnancy can cause significant morbidity and mortality. Contraceptive use and pregnancy counseling in women with HF is an essential part of their medical care. Here, we assess contraceptive use and pregnancy counseling of patients with HF at a single tertiary care center. METHODS AND RESULTS: This was a retrospective, single-center cohort study of female patients with HF with reduced ejection fraction, left ventricular assist devices (LVADs), and heart transplants who were seen in the adult advanced HF outpatient clinics. Patients were identified in the electronic health care record system, and records were reviewed to assess for documentation of contraception and pregnancy counseling. We identified 156 women of childbearing age (aged >18 to <45), seen in the HF clinics between 2018 and 2023. Patients were subdivided by their most recent diagnosis and therapy: HF with reduced ejection fraction (83 [53.2%]), LVAD (18 [11.5%]), and heart transplant (55 [35.3%]). Contraception was documented for 74% of women with HF, 56% of women with LVAD, and 85% of women with heart transplants. Pregnancy counseling was documented for 18.00% of women with HF, 0.06% of women with LVAD, and 29.00% of women with heart transplants. CONCLUSIONS: In our study, many women with HF, LVAD, or transplant have documented contraceptive therapy; however, pregnancy counseling seems to be limited. This vital aspect of medical care should be available for all patients given potential pregnancy-associated risks.

The Impact of Local Programmatic Decisions on Outcomes in Transplant-Listed Adults With Congenital Heart Disease.

BACKGROUND: We investigated variables impacting waitlist times and negative waitlist outcomes in adults with congenital heart disease (ACHD) who were waiting for orthotopic heart transplant (OHT) after the 2018 allocation change. METHODS: Adult candidates for OHT who were listed between 10/18/2018 and 12/31/2022 in the United Network for Organ Sharing database were categorized as ACHD vs non-ACHD. Waitlist time and time to upgrade for those upgraded into status 1-3 were compared by using rank-sum tests. Death/delisting for deterioration was assessed by using Fine-Gray subdistribution hazard ratios (SHRs). RESULTS: Of 15,424 OHT candidates, 589 (3.8%) were ACHD. ACHD vs non-ACHD candidates had less urgent status at initial listing (4.2% vs 4.7% listed at status 1; 17.2% vs 23.7% listed at status 2; P < 0.001), but not final listing (5.9% vs 7.6% final status 1; 35.6% vs 36.8% final status 2; P < 0.001). ACHD vs non-ACHD candidates upgraded into status 1 (65.0 vs 30.0 days; P = 0.09) and status 2 (113.0 vs 64.0 days; P = 0.003) spent longer times on the waitlist. ACHD vs non-ACHD candidates spent longer times waiting for an upgrade into status 1 (51.4 vs 17.6 days; P = 0.027) and status 2 (76.7 vs 34.7 days; P = 0.003). Once upgraded, there was no difference between groups in waitlist time to status 1 (9.7 vs 5.5 days = 0.66). ACHD vs non-ACHD candidates with a final status of 1 (20.0% vs 8.6%; SHR 2.47 [95%CI = 1.19-5.16]; P = 0.02) and 2 (8.9% vs 2.3%; SHR 3.59 [95%CI = 2.18-5.91]; P < 0.001) experienced higher rates of death and deterioration. CONCLUSIONS: ACHD candidates have longer waitlist times, have lower priority status at initial listing, wait longer for upgrades, and have higher mortality rates at the same final status as non-ACHD candidates, suggesting that they are being upgraded too late.

Impact of the Pediatric ABO Policy Change on Listings, Transplants, and Outcomes for Children Younger Than 2 Years Listed for Heart Transplantation in the United States.

BACKGROUND: We assessed the impact of the liberalized ABO pediatric policy change on candidate characteristics and outcomes for children undergoing heart transplant (HT). METHODS AND RESULTS: Children <2 years undergoing HT with ABO strategy reported at listing and HT from December 2011 to November 2020 to the Scientific Registry of Transplant Recipients database were included. Characteristics at listing, HT, and outcomes during the waitlist and post-transplant were compared before the policy change (December 16, 2011 to July 6, 2016), and after the policy change (July 7, 2016 to November 30, 2020). The percentage of ABO-incompatible (ABOi) listings did not increase immediately after the policy change (P = .93); however, ABOi transplants increased by 18% (P < .0001). At listing, both before and after the policy change, ABOi candidates had higher urgency status, renal dysfunction, lower albumin, and required more cardiac support (intravenous inotropes, mechanical ventilation) than those listed ABO compatible (ABOc). On multivariable analysis, there were no differences in waitlist mortality between children listed as ABOi and ABOc before the policy change (adjusted hazard ratio [aHR] 0.80, 95% confidence interval [CI] 0.61-1.05, P = .10) or after the policy change (aHR 1.2, 95% CI 0.85-1.6, P = .33). Post-transplant graft survival was worse for ABOi transplanted children before the policy change (aHR 1.8, 95% CI 1.1-2.8, P = .014), but not significantly different after the policy change (aHR 0.94, 95% CI 0.61-1.4, P = .76). After the policy change, ABOi listed children had significantly shorter waitlist times (P < .05). CONCLUSIONS: The recent pediatric ABO policy change has significantly increased the percentage of ABOi transplantations and decreased waitlist times for children listed ABOi. This change in policy has resulted in broader applicability and actual performance of ABOi transplantation with equal access to ABOi or ABOc organs, and thus eliminated the potential disadvantage of only secondary allocation to ABOi recipients.

Impact of pretransplant T2DM on left ventricular deformation and myocardial perfusion in heart transplanted recipients: a 3.0 T cardiac magnetic resonance study.

BACKGROUND: Pretransplant type 2 diabetes mellitus (T2DM) is associated with increased cardiovascular and all-cause mortality after heart transplant (HT), but the underlying causes of this association remain unclear. The purpose of this research was to examine the impact of T2DM on left ventricular (LV) myocardial deformation and myocardial perfusion following heart transplantation using cardiovascular magnetic resonance imaging. METHODS: We investigated thirty-one HT recipients with pretransplant T2DM [HT(DM+)], thirty-four HT recipients without pretransplant T2DM [HT(DM-)] and thirty-six controls. LV myocardial strains, including the global longitudinal, radial, and circumferential strain (GLS, GRS and GCS, respectively), were calculated and compared among groups, as were resting myocardial perfusion indices, which included time to peak myocardial signal intensity (TTM), maximum signal intensity (MaxSI), and Upslope. The relationships between LV strain parameters or perfusion indices and biochemical indicators were determined through Spearman's analysis. The impact of T2DM on LV strains in HT recipients was assessed using multivariable linear regression analyses with backward stepwise selection. RESULTS: In the HT(DM+) group, the LV GLS, GRS, and GCS exhibited significantly lower magnitudes than those in both the HT(DM-) and control groups. TTM was higher in the HT(DM+) group than in both the HT(DM-) and control groups, while no significant differences were observed among the groups regarding Upslope and MaxSI. There was a negative correlation between glycated hemoglobin and the magnitude of strains (longitudinal, r = - 0.399; radial, r = - 0.362; circumferential, r = - 0.389) (all P < 0.05), and a positive correlation with TTM (r = 0.485, P < 0.001). Regression analyses that included both pretransplant T2DM and perfusion indices revealed that pretransplant T2DM, rather than perfusion indices, was an independent determinant of LV strain (ß = longitudinal, - 0.508; radial, - 0.370; circumferential, - 0.371) (all P < 0.05). CONCLUSION: In heart transplant recipients, pretransplant T2DM has a detrimental effect on subclinical left ventricular systolic function and could potentially impact myocardial microcirculation following HT.

Heart Transplantation for Adults With Congenital Heart Disease Can Be Performed at Adult or Pediatric Hospitals With Comparable Outcomes.

INTRODUCTION: The goal of this study was to evaluate the relationship between hospital-related factors and hospital type on outcomes of heart transplantation for patients with adult congenital heart disease (ACHD). METHODS: Patients with ACHD who underwent heart transplant between 2010 and 2021 were identified using the United Network for Organ Sharing data registry. The primary outcome was post-transplant mortality. Kaplan-Meier unadjusted survival curves were compared using the log-rank test. Multivariable Cox proportional hazard models were used for risk-adjustment in evaluating the independent effect of hospital type on post-transplant mortality. RESULTS: Of 70 centers, 54 (77.1%) adult centers performed 415 (87.0%) heart transplants and 16 (22.9%) pediatric centers performed 62 (13.0%) heart transplants. Patients transplanted at pediatric centers were younger, had lower creatinine levels, and had lower body mass index. The unadjusted 1-y and 5-y survival was comparable in pediatric versus adult centers, respectively: 93.4% versus 86.6% (log-rank P = 0.16) and 87.4% versus 73.9% (log-rank P = 0.06). These findings persisted after risk-adjustment. One-year mortality hazard ratio for pediatric hospitals: 0.64 (0.22-1.89, P = 0.416) and 5-y mortality hazard ratio for pediatric hospitals: 0.53 (0.21-1.33, P = 0.175). Rates of acute rejection, postoperative stroke, and new-onset postoperative dialysis were also comparable. CONCLUSIONS: Heart transplantation for patients with ACHD can be performed safely in adult centers. The majority of heart transplant for ACHD in the United States are performed at adult hospitals. However, further research is needed to delineate the impact of individual surgeon characteristics and hospital-related factors on outcomes.

Outcomes of Heart Transplant Using High Donor Sequence Number Offers.

INTRODUCTION: Higher donor sequence numbers (DSNs) might spark provider concern about poor donor quality. We evaluated characteristics of high-DSN offers used for transplant and compared outcomes of high- and low-DSN transplants. MATERIALS AND METHODS: Adult isolated heart transplants between January 1, 2015, and December 31, 2022, were identified from the organ procurement and transplantation network database and stratified into high (≥42) and low (<42) DSN. Postoperative outcomes, including predischarge complications, hospital length of stay, and survival at 1 and 3 y, were evaluated using multivariable regressions. RESULTS: A total of 21,217 recipients met the inclusion criteria, with 2131 (10.0%) classified as high-DSN. Donor factors associated with greater odds of high-DSN at acceptance included older age, higher creatinine, diabetes, hypertension, and lower left ventricular ejection fraction. Recipients accepting high-DSN offers were older and more likely to be female, of blood type O, and have lower status at transplant. High- and low-DSN transplants had similar likelihood of stroke (3.2% versus 3.5%; P = 0.97), dialysis (12.3% versus 13.5%; P = 0.12), pacemaker implant (2.3% versus 2.1%; P = 0.64), had similar lengths of stay (16 [12-24] versus 16 [12-25] days, P = 0.38), and survival at 1 (91.6% versus 91.6%; aHR 0.85 [0.72-1.02], P = 0.08) and 3 y (84.2% versus 85.1%; aHR 0.91 [0.79-1.05], P = 0.21) post-transplant. CONCLUSIONS: High-DSN (≥42) was not an independent risk factor for post-transplant mortality and should not be the sole deterrent to acceptance. Accepting high-DSN organs may increase access to transplantation for lower-status candidates.

Center and Individual Willingness to Consider Heart and Lung Offers From Donors With Hepatitis C.

INTRODUCTION: Transplants with hearts and lungs from donors with hepatitis C virus (HCV D+) have been proven safe and effective since development of direct-acting antivirals, yet the presence of HCV + persists as a reason to decline organs. METHODS: We identified adult candidates listed January 1, 2015-March 8, 2023 for heart or lung transplant using the Scientific Registry of Transplant Recipients. We identified individual-level and center-level characteristics associated with listing to consider HCV D+ offers using multilevel logistic regression in a multivariable framework. RESULTS: Over the study period, the annual percentage of candidates willing to consider HCV D+ offers increased for both heart (9.5%-74.3%) and lung (7.8%-59.5%), as did the percentage of centers listing candidates for HCV D+ heart (52.9%-91.1%) and lung (32.8%-82.8%) offers. Candidates at centers with more experience with HCV D+ transplants were more likely to consider HCV D+ organ offers. After adjustment, listing center explained 70% and 78% of the residual variance in willingness to consider HCV D+ hearts and lungs, respectively. CONCLUSIONS: Although listing for consideration of HCV D+ offers has increased, it varies by transplant center. Center-level barriers to consideration of HCV D+ organs reduce recipients' transplant access.

Real-life use of letermovir prophylaxis for cytomegalovirus in heart transplant recipients.

INTRODUCTION: Cytomegalovirus (CMV) remains the predominant opportunistic infection following solid organ transplantation (SOT). While valganciclovir is the drug of choice for CMV prophylaxis, its utility can be compromised due to the risk of cytopenia. Letermovir, a novel agent approved for CMV prophylaxis in allogeneic hematopoietic stem cell transplant recipients and high-risk kidney transplant recipients, exhibits reduced toxicity. This study aims to present the practical application of letermovir as both primary and secondary prophylaxis against CMV in heart transplant recipients (HTR). METHODS: In this observational, retrospective, single-center study, we included all consecutive adult HTRs from June 2020 to January 2022 who were administered letermovir for CMV prophylaxis. We documented instances of CMV breakthrough infections, side effects related to letermovir, changes in neutropenia following the switch from valganciclovir to letermovir, and any drug interactions with the immunosuppressive regimen. RESULTS: The study comprised 10 patients: two received primary prophylaxis with letermovir due to a high risk of CMV infection (donor-positive, recipient-negative serostatus), and eight received it as secondary prophylaxis following a CMV infection. The median duration of letermovir administration was 8 months (range 3-12 months). No CMV breakthrough infections were reported while on prophylaxis. However, three patients experienced CMV breakthrough infections after discontinuing letermovir prophylaxis (30%). No significant side effects were observed, although one patient reported digestive intolerance. Among the nine patients on tacrolimus, six needed reduced doses after switching to letermovir. CONCLUSION: This real-life study appears to support the effectiveness of letermovir prophylaxis in HTR. Nonetheless, the risk of CMV infection post-treatment cessation is notable. Further drug monitoring and research on the efficacy of letermovir for CMV prophylaxis in SOT patients is warranted.

A quantitative assessment of renal function utilizing albuminuria in pediatric heart transplant recipients.

INTRODUCTION: Kidney disease is common after pediatric heart transplantation. Serum creatinine-based glomerular filtration rate is the most frequently reported measure of kidney function. Albuminuria is an additional marker of kidney dysfunction and is not well described in this population. In this study, we evaluate the prevalence and degree of albuminuria and describe clinical factors associated with albuminuria in a cohort of pediatric heart transplant recipients. METHODS: This was a cross-sectional study of pediatric heart transplant recipients. Albuminuria was assessed using spot urine albumin-to-creatinine ratio collected at the most recent annual screening cardiac catheterization through August 2019. RESULTS: In 115 patients at a median duration of 10.2 years post-transplant, 39% had albuminuria. Stage 3 or greater chronic kidney disease was present in 6%. The immunosuppressive regimen at the time of measurement contained a calcineurin inhibitor (CNI) in 88% and a proliferation signal inhibitor (PSI) in 62%. In multivariable modeling, lower eGFR, PSI use, and younger age at transplant were associated with higher levels of albuminuria, whereas CNI use was associated with lower levels of albuminuria. CONCLUSION: Albuminuria is a prevalent finding in medium-term follow up of pediatric heart transplant recipients, reflecting kidney injury, and is associated with other markers of kidney dysfunction, such as low eGFR. Younger age at transplant, lower eGFR, and PSI use were among the associations with albuminuria.

Does bortezomib influence pre-transplant desensitization therapy or benefit post-heart transplant outcomes for highly sensitized patients?

BACKGROUND: The use of bortezomib which is a proteasome inhibitor has been demonstrated to be efficacious in small number of patients as a desensitization strategy in heart transplant. We reviewed our single center's experience using Bortezomib along with plasmapheresis as desensitization therapy for highly sensitized patients to assess pre- and post-transplant outcomes. METHOD: We assessed 43 highly sensitized patients awaiting HTx (defined as cPRA > 50%) between 2010 and 2021 who underwent desensitization therapy with bortezomib. Only those patients who subsequently underwent HTx were included in this study. Enrolled patients received up to four doses of bortezomib (1.3 mg/m2 ) over 2 weeks in conjunction with plasmapheresis. The efficacy of PP/BTZ was assessed by comparing the calculated panel reactive antibodies to HLA class I or class II antigens. Post-transplant outcomes including overall survival and incidence of rejection were compared to those of non-sensitized patients (PRA < 10%, n = 649) from the same center. RESULTS: The average cPRA prior to PP/BTZ was 94.5%. Post-PP/BTZ there was no statistically significant decline in mean cPRA, class I cPRA, or class II cPRA, though the average percentage decrease in class I cPRA (8.7 ± 17.0%) was higher than the change in class II cPRA (4.4 ± 13.3%). Resulted were also replicated with C1q-binding antibodies showing more effect on I class compared to class II (15.0 ± 37.4% vs. 6.8 ± 33.6%) as well as with 1:8 dilutional assay (14.0 ± 23.0% vs. 9.1 ± 34.9%). Additionally, PP/BTZ treated patients and the control group of non-sensitized patients had similar overall 1 year survival (95.4 vs. 92.5%) but patients with PP/BTZ had increased incidence of AMR (79.1% vs. 97.1%, p = < .001), any treated rejection (62.8% vs. 86.7%, p = < .001) and de novo DSA development (81.4% vs. 92.5%, p = .007). Major side effects of PP/BTZ included thrombocytopenia (42%), infection requiring antibiotics (28%), and neuropathy (12%). CONCLUSION: The use of bortezomib in highly sensitized patients does not significantly lower circulating antibodies prior to heart transplantation. However, its use may improve the chances of obtaining an immuno-compatible donor heart and contribute to acceptable post-transplant outcomes.

Bridge-to-transplant temporary mechanical circulatory support and risk of allosensitization.

INTRODUCTION: Since the 2018 change in the US adult heart allocation policy, more patients are bridged-to-transplant on temporary mechanical circulatory support (tMCS). Previous studies indicate that durable left ventricular assist devices (LVAD) may lead to allosensitization. The goal of this study was to assess whether tMCS implantation is associated with changes in sensitization. METHODS: We included patients evaluated for heart transplants between 2015 and 2022 who had alloantibody measured before and after MCS implantation. Allosensitization was defined as development of new alloantibodies after tMCS implant. RESULTS: A total of 41 patients received tMCS before transplant. Nine (22.0%) patients developed alloantibodies following tMCS implantation: 3 (12.0%) in the intra-aortic balloon pump group (n = 25), 2 (28.6%) in the microaxial percutaneous LVAD group (n = 7), and 4 (44.4%) in the veno-arterial extra-corporeal membrane oxygenation group (n = 9)-p = .039. Sensitized patients were younger (44.7 ± 11.6 years vs. 54.3 ± 12.5 years, p = .044), were more likely to be sensitized at baseline - 3 of 9 (33.3%) compared to 2 out of 32 (6.3%) (p = .028) and received more transfusions with red blood cells (6 (66.6%) vs. 8 (25%), p = .02) and platelets (6 (66.6%) vs. 5 (15.6%), p = .002). There was no significant difference in tMCS median duration of support (4 [3,15] days vs. 8.5 [5,14.5] days, p = .57). Importantly, out of the 11 patients who received a durable LVAD after tMCS, 5 (45.5%) became sensitized, compared to 4 out of 30 patients (13.3%) who only had tMCS-p = .028. CONCLUSIONS: Our findings suggest that patients bridged-to-transplant with tMCS, without significant blood product transfusions and a subsequent durable LVAD implant, have a low risk of allosensitization. Further studies are needed to confirm our findings and determine whether risk of sensitization varies by type of tMCS and duration of support.

Assessment of immunosuppression induction with basiliximab compared to antithymocyte-globulin in adult heart transplant patients.

BACKGROUND: Patients undergoing heart transplants are at risk of rejection which can have significant morbidity and mortality. Induction immunosuppression at the time of transplant reduces the early risk and has additional benefits. The induction agent of choice within our program was changed from rabbit antithymocyte-globulin (rATG) to basiliximab, so it was necessary to evaluate whether this had any impact on patient outcomes. OBJECTIVES: Our primary objective was to describe rejection, infection, and other outcomes in adult heart transplant patients at the University of Alberta Hospital in Edmonton, Canada. METHODS: This study was a nonrandomized, retrospective cohort study. RESULTS: Sixty-three patients were included with median ages 50 years versus 54 years. More female patients received rATG (20% vs. 42.4%). The most common indication for transplant in both cohorts was ICM (63.3% vs. 57.6%). Patients who received rATG had significantly higher PRA (0% vs. 43%, p < .001). Acute rejection episodes were similar between basiliximab and rATG at 3 months (16.7% vs. 15.1%; p = 1.0) and 6-months (30.0% vs. 18.1%; p = .376). Infections were not statistically different with basiliximab compared to rATG at 3-months, 43.3% vs. 63.6% and at 6-months 60.0% vs. 66.7%). There were no fatalities in either group. CONCLUSIONS: Our study did not demonstrate differences in rejection with basiliximab compared to rATG. Mortality did not differ, but basiliximab-treated patients had fewer infections and infection-related hospitalizations than those treated with rATG. Larger studies with longer durations are needed to more completely describe the differences in rejection and infectious outcomes.