Does lung procurement and exposure to Perfadex impact heart transplantation outcomes.

INTRODUCTION: Some studies have shown increased incidence of Primary Graft Dysfunction (PGD) after heart and lung procurement for heart transplant recipients. There have been limited investigations of the impact of lung procurement on heart procurement and the potential effects of the exposure to the type of lung preservation solution, the volume of the lung preservation solution and adequacy of decompression of the heart during heart and lung procurement and the impact on heart transplant outcomes. METHODS: Adult heart transplant recipients in the UNOS database recorded from January 1, 2000 to June 30, 2022 formed the study cohort. Any heart that was procured with a lung team that utilized Perfadex preservation solution (XVIVO, Gothenburg, Sweden) was classified as exposed to Perfadex and otherwise classified as not exposed to Perfadex. Lung procurements performed with a preservation solution other than Perfadex or unknown were excluded (n = 2486). Simple comparisons were made with t-tests or chi-squared tests. Logistic regression models were used to predict 30 day and 1 year survival. Accelerated failure time models were employed to analyze time to death and time to rejection. RESULTS: The cohort consisted of 34 192 heart transplants, of which 21 928 donors were not exposed to Perfadex (64.1%). There were statistically, but not clinically, significant differences in donor characteristics for these groups including in donor age (33.34 ± 11.01 not exposed vs. 30.70 ± 10.69 exposed; p < .001), diabetic donor (4% not exposed vs. 3% exposed; p = .004), and ischemic time (3.28 ± 1.09 h not exposed vs. 3.24 ± 1.05 h exposed; p = .002). In adjusted models, for all included donors, Perfadex exposure was associated with increased short term mortality, but no long term difference (1 year mortality OR 1.10, p = .014). CONCLUSION: Perfadex exposure was associated with increased short-term mortality for heart transplant recipients. Mechanistic investigation is warranted.

Veno-venous ECLS rescue for a heart transplant recipient with COVID-19, a case report.

The potential for increased rates of morbidity of SARS-CoV-2 within immunocompromised populations has been of concern since the pandemic's onset. Transplant providers and patients can face particularly challenging situations, in the current settings as data continues to emerge for the prevention and treatment of the immunocompromised subpopulation. This case report details a patient 9-months post orthotopic heart transplant that developed SARS-CoV-2 infection despite two prior doses of the Pfizer-BioNtech COVID-19 vaccine, and had successful rescue from refractory hypoxemia with veno-venous extracorporeal membrane oxygenation (VV ECLS).

Expanding heart transplantation in 2022 and beyond.

PURPOSE OF REVIEW: Despite advances in the technology of mechanical circulatory support, the need for heart transplantation continues to grow. The longevity of heart transplants continues to be superior to mechanical solutions, though the short-term differences are shrinking. In this review, we cover three timely developments and summarize the recent literature. RECENT FINDINGS: After stagnant rates of heart transplant activity for some years, recently, transplant volume has increased. The developments that have ignited interest have been the use of hepatitis C infected donors, which can now be safely transplanted with the advent of curative oral regimens, and the worldwide use of donors following withdrawal of life support as opposed to traditional brain death donors. In addition, the recent experience of human cardiac xenotransplantation has been very exciting, and though it is not of clinical utility yet, it holds the promise for a virtually unlimited supply of organs at some time in the future. SUMMARY: Much work remains to be done, but together, all three of these developments are exciting and important to be aware of in the future. Each will contribute to additional donors for human heart transplantation and hopefully will alleviate suffering and death on the waiting list.

Does donor treatment with inotropes and/or vasopressors impact post-transplant outcomes?

PURPOSE: The purpose was to evaluate the effects of the most commonly used cardiac donor inotropes/vasopressors on subsequent post-heart transplant survival. METHODS: Adult heart transplant recipients from January 2000 to June 2022 were identified in the United Network for Organ Sharing (UNOS) database. Exclusion criteria included: multiorgan transplants, donor age < 15, and recipient age < 18. Donors receiving vasoactive medications at the time of procurement were compared to donors not receiving these medications. Those on vasoactive medications were stratified by medication: phenylephrine, dopamine, dobutamine, norepinephrine and epinephrine, the combination of these agents, and the concomitant administration of vasopressin with any single agent alone or in combination. The primary area of interest was short-and-long-term survival. Survival at 30 days, 1 year, and long-term (Median = 13.6 years) was compared using logistic and Cox models to quantify survival endpoints. RESULTS: A total of 45,198 donors met inclusion criteria and had data on the use of vasoactive agents available. Mean donor age was 32.3 years with 71% male. Vasoactive medications and potential combinations included phenylephrine in 8156 donors (18.0%), dopamine in 9550 (21.1%), dobutamine in 718 (1.6%), epinephrine in 332 (.73%), and norepinephrine in 4854 (10.7%). A total of 25,856 donors (57.2%) were receiving vasopressin at the time of procurement. There was no impact of donor inotropes on 30-day survival. Donors receiving one inotrope and no vasopressin were associated with increased 1 year mortality (OR 1.14; p = .021), as were donors receiving 2+ inotropes and no vasopressin (OR 1.26; p = .006). For individual agents, 1 year mortality was increased for dopamine (OR 1.11; p = .042) and epinephrine (OR 1.59; p = .004). CONCLUSIONS: There is no difference in heart transplant recipient survival at 30 days when the donor is receiving inotropes without vasopressin at the time of procurement. Inotropic support without vasopressin is associated with greater 1 year mortality. The impact of donor inotropic support on long term heart transplant survival, and the interaction with vasopressin warrants further study.

Positive donor blood cultures are not associated with worse heart transplant survival.

BACKGROUND: Recent evidence has demonstrated that transplantation of hearts with blood culture positive donors (BCPDs) to pediatric recipients is safe and effective. Few studies have analyzed the effect of BCPD on adult heart transplant recipients. METHODS: The United Network for Organ Sharing (UNOS) database was retrospectively reviewed from September, 1987 to March, 2021. Exclusion criteria included pediatric donors/recipients, donor ejection fraction <10% or >85%, inactive listed recipients, donors missing blood cultures, and recipients missing follow-up time. Outcomes were compared with fully adjusted logistic models. To account for discrepancies in BCPD and non-BCPD covariates, an inverse proportionally weighted model with regression adjustment (IPWRA) was used. RESULTS: A total of 60 592 donors were non-BCPD, while 4009 were BCPD. 7% of hearts not transplanted were BCPD, while 6% of hearts transplanted were BCPD (p = .001). These rates have been nearly constant since 2005. There were no differences in short term survival between the two groups in the adjusted or IPWRA models (p = .103 and .277, respectively). Additionally, the BCPD group had longer ischemic time (3.24 vs. 3.06 h, p < .001), older donor age (32.73 vs. 31.65 years, p < .001), and older recipient age (52.76 vs. 52.09 years, p = .001). The IPWRA revealed an average additional 3.4 years of overall survival and 2.25 years of graft function for BCPD versus non-BCPD recipients, although these results failed to reach statistical significance (p = .387 and .527, respectively). CONCLUSIONS: Given the need for more donor hearts, donors with positive blood cultures should be considered. Great care in evaluating such patients is advised to eliminate donors with untreated infections, while carefully selected donors can be considered and used.

Conversion to tacrolimus alone compared to full immunosuppression following cardiac transplantation (TACTFUL).

BACKGROUND: Cardiac transplantation requires lifelong immunosuppressant medications to prevent rejection. However, some patients may not tolerate multiple immunosuppressants due to adverse effects. At our institution, patients may be converted to monotherapy with tacrolimus if unable to tolerate a combination regimen. This study evaluated the outcomes among patients converted to tacrolimus monotherapy compared with those maintained on combination immunosuppression. METHODS: This single-center, retrospective cohort study included patients who received heart transplants at Sentara Norfolk General Hospital between January 2015 and July 2021. Patients were classified as receiving tacrolimus monotherapy (Mono) or combination immunosuppression (Combo). The primary outcome was all-cause mortality with key secondary outcomes including incidence of 2R/3R rejection, necessity for renal replacement therapy, and infection. RESULTS: 112 patients were included (Mono = 25, Combo = 87). Median age at transplant was 53.8 years (Mono) and 52.1 years (Combo). The most common reasons for conversion to monotherapy were leukopenia, infection, and gastrointestinal (GI) distress. There was no difference in mortality (0 in Mono, 11 in Combo; p = .09) or percentage of patients with 2R/3R rejection (24% in Mono, 32.2% in Combo; p = .43). No Mono group patients experienced rejection after converting from combination therapy. 24% of Mono group patients resumed at least one additional immunosuppressive medication during the study period. Median time to monotherapy was 9.0 months, with a total median duration on monotherapy of 16.0 months. A median of 3.3 years of follow-up was observed for patients in Mono and 3.4 years in Combo (p = .29). CONCLUSION: Selected patients who do not tolerate combination immunosuppression can be safely transitioned to tacrolimus monotherapy as a means of controlling adverse events without an increased risk of mortality or rejection.

Do outcomes for heart transplantation differ based on donor and recipient race?

PURPOSE: There are limited data examining the impact of both donor and recipient race on outcomes following orthotopic heart transplant (OHT). The purpose of this study was to evaluate the relationship between donor and recipient race and OHT outcomes. METHODS: The United Network for Organ Sharing (UNOS) database was retrospectively reviewed from January 2000 to March 2018 for donor hearts. A comparison was conducted based on donor and recipient race (White, Black, Hispanic, Other/Unknown). Races for which there were limited numbers were excluded from the analysis (Asian, n = 1292; American Indian, n = 132; Pacific Islander, n = 132, Multiple ethnicities, n = 225). The primary endpoint was survival at 30 days, 1 year survival, and post-transplant rejection. Logistic and Cox models were used to quantify survival endpoints. RESULTS: A total of 41 841 OHT were included. Of the recipients, 29 894 (71%) were White, 8475 (20%) were Black, and 3472 (8%) were Hispanic. Of the donors 27 783 (66%) were White, 6277 (15%) were Black, 6576 (16%) were Hispanic, and 1205 (3%) were Unknown/Other race. In a comparison of recipient demographics, White recipients were older (54.09 ± 12.21 years) compared to Black (49.44 ± 12.83 years) and Hispanic (49.97 ± 13.27 years) recipients. All other differences between groups were not clinically significant. Black recipients were more likely to receive a heart with an "urgent" status (probability .80) compared to White (.73) and Hispanic (.75) recipients (p < .001). Hispanic recipients were more likely to receive a transplant when listed as "non-urgent" (Probability .47) compared to White (.37) and Black (.30) recipients (p < .001). In terms of outcomes, compared to White recipients, Hispanic patients experienced a decreased 30-day survival (OR 1.27; p = .011) and 1-year survival (OR 1.17; p = .016). In comparing Donor/Recipient combinations compared to a White Donor/White Recipient combination, overall survival was decreased in White donor/African American recipient (HR 1.36; p < .001), African American donor/African American recipient (HR 1.41; p < .001) and Hispanic donor/African American recipient (HR 1.30; p < .001) combinations (Table 1). CONCLUSIONS: African American and Hispanic recipients have decreased survival compared to White recipients after heart transplant. The African American donor does not decrease survival. Racial differences still exist in donor and recipient characteristics and recipient outcomes after OHT. Increasing the donor pool for all races and ethnicities would potentially benefit all recipients. Continued study is warranted in order to minimize these differences among recipients and identify factors that could be contributing to decreased survival, in order to optimize outcomes for African American and Hispanic recipients post-transplant and eliminate disparities.

Guidelines and principles for the care of the cardiothoracic transplant patient in the intensive care unit.

Heart and lung transplant recipients require care provided by clinicians from multiple different specialties, each contributing unique expertise and perspective. The period the patient spends in the intensive care unit is one of the most critical times in the perioperative trajectory. Various organizational models of intensive care exist, including those led by intensivists, surgeons, transplant cardiologists, and pulmonologists. Coordinating timely efficient intensive care is an essential and logistically difficult goal. The present work product of the American Society of Transplantation's Thoracic and Critical Care Community of Practice, Critical Care Task Force outlines operational guidelines and principles that may be applied in different organizational models to optimize the delivery of intensive care for the cardiothoracic organ recipient.

The changing face of cardiogenic shock: definitions, epidemiology, and severity assessment.

PURPOSE OF REVIEW: Cardiogenic shock (CS) has been recognized for >50 years, most commonly in the setting of myocardial infarction. This review covers recent advances in the definitions, epidemiology and severity assessment of cardiogenic shock. RECENT FINDINGS: In this review, the authors discuss the evolving definitions of cardiogenic shock, detailing the early approaches as well as more contemporary ideas. The epidemiology of CS is reviewed and then granular detail on the assessment of shock severity is provided including the role of lactate measurement and invasive hemodynamic assessment. The development of the Society for Cardiac Angiography and Intervention (SCAI) consensus statement on Classification of Cardiogenic Shock is reviewed by the principal authors. The revised SCAI Shock document is reviewed as well and the future directions for assessment of shock along with clinical applications are reviewed. SUMMARY: Cardiogenic shock mortality has not changed in a significant way in many years. Recent advances such as more granular assessment of shock severity have the potential to improve outcomes by allowing research to separate the patient groups which may respond differently to various therapies.

Do vasoactive medications impact donor hearts clinical outcomes in pediatric heart transplantation?

OBJECTIVES: There is limited data examining donor vasopressor and/or inotrope medications (vasoactives) on pediatric orthotopic heart transplant (OHT) outcomes. We aim to evaluate the effects of vasoactives on pediatric OHT outcomes. METHODS: The United Network for Organ Sharing database was retrospectively reviewed from January 2000 to March 2018 for donor hearts. Exclusion criteria included multiorgan transplants and recipient age >18. Donors receiving vasoactives at the time of procurement were compared to donors not on vasoactives, including the number of vasoactives and the type. End-points of interest were survival at 30 days and 1 year as well as post-transplant rejection at 1 year. Logistic and Cox models were used to quantify survival end-points. RESULTS: Of 6462 donors, 3187 (49.3%) were receiving at least one vasoactive. Comparing any vasoactive medication versus none, there was no difference in 30-day survival (p = .27), 1 year survival (p = .89), overall survival (p = .68), or post-transplant rejection (p = .98). There was no difference in 30-day survival for donors receiving 2 or more vasoactive infusions (p = .89), 1 year survival (p = .53), overall survival (p = .75), or post-transplant rejection at 1 year (p = .87). Vasopressin was associated with decreased 30-day mortality (OR = 0.22; p = .028), dobutamine with decreased 1-year mortality (OR = 0.37; p = .036), overall survival (HR = 0.51; p = .003), and decreased post-transplant rejection (HR = 0.63; p = .012). CONCLUSIONS: There is no difference in pediatric OHT outcomes when the cardiac donor is treated with vasoactive infusions at procurement. Vasopressin and dobutamine were associated with improved outcomes. This information can be used to guide medical management and donor selection.

Safety and efficacy of ProtekDuo right ventricular assist device: A systemic review.

BACKGROUND: Right ventricular failure is associated with increased morbidity and mortality. The ProtekDuo (Livanova, Uk) is a dual-lumen cannula that allows for percutaneous right ventricular support and may be connected to a centrifugal blood pump such as the TandemHeart or LifeSparc (Livanova, UK). This systematic review aims to evaluate the safety and efficacy of ProtekDuo right ventricular support and evaluate potential clinical variables that can influence outcomes. METHODS: PubMed, MEDLINE, SCOPUS, EMBASE, and the Cochrane Library were systematically searched. Studies meeting inclusion criteria, where ProtekDuo was used as the right ventricular assist device with reported numerical death counts for mortality as outcome measures. The primary endpoints were in-hospital 30-day and 1-year mortality rates. Secondary endpoints included ICU length of stay, conversion rates to surgical RVADs, ProtekDuo wean rates, duration of use of ProtekDuo, and adverse event rates. RESULTS: Of 49 studies reviewed, 7 met inclusion criteria with study periods between October 2014 and November 2019. ProtekDuo was utilized due to RV failure post-LVAD insertion in 64.8% (68/105) of patients. In-hospital mortality, 30-day mortality, and 1-year mortality ranged between 9%-46%, 15%-40%, and 19%-40%, respectively. Weaning from ProtekDuo and conversion to surgical RVAD ranged between 24%-91% and 11%-35%, respectively. The ICU stay average ranged from 15.8 to 36 days and ProtekDuo mean support duration ranged from 10.5 to 58 days. CONCLUSION: The ProtekDuo cannula is increasingly utilized as a right ventricular support device. Despite the sparse retrospective data available with variable patient characteristics and study design, percutaneous RV mechanical support via ProtekDuo cannula is a safe and feasible option.

Influence of intra-aortic balloon pump on mortality as a function of cardiogenic shock severity.

BACKGROUND: Randomized studies of intra-aortic balloon pump (IABP) in cardiogenic shock (CS) have only included on patients with acute coronary syndromes (ACS) without stratification according to shock severity. We examined the association between IABP and mortality in CS patients across the Society for Cardiovascular Angiography and Intervention (SCAI) shock stages. METHODS: We included cardiac intensive care unit patients admitted from 2007 to 2015 with CS from any etiology. In-hospital mortality associated with IABP was examined in each SCAI shock stage. Multivariable logistic regression was performed using inverse probability of treatment weighting (IPTW) to determine the association between IABP and in-hospital mortality. RESULTS: We included 934 patients, with a mean age of 68 ± 14 years; 60% had ACS. The distribution of SCAI shock stages was: B, 41%; C, 13%; D, 38%; E, 8%. In-hospital mortality was lower in the 39% of patients who received IABP (27% vs. 43%, adjusted OR with IABP after IPTW 0.53, 95% CI 0.40-0.72, p < .0001). IABP use was associated with lower crude in-hospital mortality in each SCAI shock stage (all p < .05, except p = .08 in SCAI shock stage E). We did not observe any significant heterogeneity in the association between IABP use and in-hospital mortality as a function of SCAI shock stage. CONCLUSIONS: Patients with CS who were selected to receive an IABP had lower in-hospital mortality, without differences in this effect across the SCAI shock stages. Future studies should account for the severity and etiology of shock when evaluating the efficacy of IABP for CS.

Variability in reporting of key outcome predictors in acute myocardial infarction cardiogenic shock trials.

BACKGROUND: Among acute myocardial infarction patients with cardiogenic shock (AMICS), a number of key variables predict mortality, including cardiac arrest (CA) and shock classification as proposed by Society for Cardiovascular Angiography and Intervention (SCAI). Given this prognostic importance, we examined the frequency of reporting of high risk variables in published randomized controlled trials (RCTs) of AMICS patients. METHODS: We identified 15 RCTs enrolling 2,500 AMICS patients and then reviewed rates of CA, baseline neurologic status, right heart catheterization data, lactate levels, inotrope and vasopressor requirement, hypothermia, mechanical ventilation, left ventricular ejection fraction (LVEF), mechanical circulatory support, and specific cause of death based on the primary manuscript and Data in S1. RESULTS: A total of 2,500 AMICS patients have been enrolled in 15 clinical trials over 21 years with only four trials enrolling >80 patients. The reporting frequency and range for key prognostic factors was: neurologic status (0% reported), hypothermia (28% reported, prevalence 33-75%), specific cause of death (33% reported), cardiac index and wedge pressure (47% reported, range 1.6-2.3 L min-1  m-2 and 15-24 mmHg), lactate (60% reported, range 4-7.7 mmol/L), LVEF (73% reported, range 25-45%), CA (80% reported, prevalence 0-92%), MCS (80% reported, prevalence 13-100%), and mechanical ventilation (93% reported, prevalence 35-100%). This variability was reflected in the 30-day mortality which ranged from 20-73%. CONCLUSIONS: In a comprehensive review of seminal RCTs in AMICS, important predictors of outcome were frequently not reported. Future efforts to standardize CS trial data collection and reporting may allow for better assessment of novel therapies for AMICS.

Cardiac donors with renal impairment: Usage and outcomes after heart transplant.

INTRODUCTION: Utilization of hearts from donors with significant renal dysfunction and the impact of donor renal function on outcomes following heart transplant (HT) is unknown. We sought to investigate the trends, characteristics and outcomes associated with these donor hearts and the impact of donor renal function on survival and graft failure in adult HT recipients. METHODS: We reviewed the Scientific Registry of Transplant Recipients (SRTR) and summarized trends, characteristics and outcomes of hearts from adult donors by renal impairment. Single-organ HTs were evaluated and stratified by donors with estimated glomerular filtration rate (eGFRs) < and ≥30 ml/min. We constructed Cox proportional hazards regression models to compare time-to-mortality over 30-day, 1-, 3-, and 5-year time-horizons between groups, and the association of donor eGFR group with graft failure. RESULTS: A total of 162,586 adults were evaluated for cardiac donation, of which, 22,780 (14%) had an eGFR ≤ 30 ml/min. Donors with an eGFR ≤ 30 ml/min increased over time, from 7.2% (358/4966) in 2000 to a high of 19.5% (2283/11,728) in 2020. Such donors were significantly more likely discarded (not offered (7.9% vs. 9.8%, p < .001) or accepted (62.6% vs. 72.2%, p < .001), and less likely to be transplanted (18.0 % vs. 29.5%; p < .001). Of 41,044 HT recipients, 3906 (9.5%) had hearts from such donors. Primary graft failure was similar between groups (OR 1.20, 95% CI .91-1.58; p = .1) while adjusted mortality was lower for recipients from donors with eGFR ≤ 30 ml/min. CONCLUSIONS: More than two-third of hearts from donors with renal dysfunction are discarded. Recipients from donors with renal dysfunction sustained lower mortality post HT during the study period. Increased evaluation and utilization of donors with renal dysfunction has the potential to expand the critically low donor pool.

Functional status of heart transplant recipients predicts survival.

INTRODUCTION: Recipient functional status prior to transplantation can significantly impact post-transplant survival. METHODS: The United Network for Organ Sharing database was queried for adult heart transplants including data on functional capacity and from February 1, 2005 to March 1, 2021; there were 32 875 cases included. The four functional categories studied were based on adult daily activities of living and were separated into total assistance required, some assistance required, no assistance required, and near death. Survival outcomes were compared for recipient's pretransplant level of functional status versus those with near death status. These were compared using adjusted logistic regression (odds of death at 30 days and 1 year) and conditional Cox models (overall survival and time until post-transplant rejection). All models were adjusted for donor age, sex, ethnicity, ischemic time, as well as recipient age, sex, ethnicity, length of stay, UNOS region, ventricular assist device, creatinine, days on the waiting list, and status at transplant. RESULTS: There were 12 953 recipients classified as "near death" or "severely disabled"; 7711 "required total assistance in daily living", 7,328 "needed some", and 4883 "needed none". In adjusted models, the probabilities of death for the lowest functioning groups within 30 days and 1 year were 5% and 10%, respectively. Those "requiring total assistance" had analogous probabilities of 3% (OR = 0.58; p < 0.001) and 9% (OR = 0.81; p < 0.001). Those "requiring some assistance" had probabilities of 3% (OR = 0.56; p < 0.001) and 9% (OR = 0.74; p < 0.001). Lastly, those "requiring no assistance" had probabilities of death of 2% (OR = 0.35; p < 0.001) and 7% (OR = 0.63; p < 0.001). CONCLUSION: Recipient functional status assessed pre-transplant and recorded in the UNOS database is a strong predictor of post-transplant survival.

The utilization and safety of apixaban for therapeutic anticoagulation in heart transplant population requiring routine endomyocardial biopsies.

PURPOSE: Routine endomyocardial (EM) biopsies pose a challenge in the management of heart transplant recipients requiring anticoagulation. Apixaban is a direct-acting oral anticoagulant (DOAC) with a short half-life allowing for brief interruptions of anticoagulation for procedures. The study objective was to determine the safety and efficacy of apixaban in heart transplant patients undergoing EM biopsies. METHODS: This retrospective case series evaluated patients with a heart transplant from April 1, 2017 to July 30, 2020 who were treated with apixaban within 90 days post-transplant. The primary outcome was the occurrence of a bleeding or thrombotic event. RESULTS: A total of 12 patients with >100 biopsies were included. The median age was 54 years (IQR 37-59) with a mean weight of 91 ± 20 kg. There were no bleeding or thrombotic events. During therapy, patients underwent an average of eight biopsies. The median time from transplant to initiation of apixaban was 39.5 days (range 9-77). Therapy was maintained without any need for reversal for a median of 276 days (IQR 45-245). CONCLUSIONS: Apixaban is safe to use for anticoagulation of heart transplant recipients undergoing routine biopsies. Using apixaban allows for a short interruption of therapeutic anticoagulation to accommodate a biopsy without increased risk of bleeding.

Ischemic time and patient outcomes after the 2018 UNOS donor heart allocation system change.

BACKGROUND: The allocation system for heart donors in the United States changed on October 18, 2018. The typical distance from donor hospitals to recipient hospitals has increased as has the ischemic time. We investigated patient outcomes with the new allocation system and the differential effects of ischemic time under both the old and new allocation schemas. METHODS: The United Network for Organ Sharing Registry (UNOS) was queried for data regarding heart transplants occurring from October 1, 1987 to March 1, 2021. In total, 62,301 adult heart transplants were examined. Survival outcomes at 30 days and 1 year and ischemic times were compared via adjusted logistic and Cox models (overall survival and time until post-transplant rejection). RESULTS: Mean ischemic time was slightly increased in the new system (3.43 h vs. 3.03 h, p < .001). Survival differences between old versus new systems were not observed in adjusted models (p = .818). However, there was evidence to suggest longer ischemic times are more detrimental to long-term survival under the new system (hazard ratio [HR] = 1.15 per hour increase; p = .001) versus the old system (HR = 1.08 per hour increase; p < .001), although this relationship did not reach statistical significance (p = .150). CONCLUSIONS: Although travel distances have significantly increased under the new allocation system, survival outcomes remain largely unchanged. Ischemic time is an influential factor in recipient survival that should be limited during organ transport. Further studies on the impact of travel distances and ischemic time under the new allocation system are needed.

Better together: a reappraisal of heterotopic heart transplantation.

Heterotopic heart transplantation (HHT) is rare in the modern era. When used as a biologic left ventricular assist, HHT provides pulsatile flow, supports the left ventricle with a physiologic cardiac output, responds to humoral stimuli, and with modern immunosuppression may offer long-term untethered survival. This study was undertaken to compare survival of HHT with orthotopic heart transplantation (OHT) to assess its viability in the modern era. In the United Network for Organ Sharing database, from January 1999 to December 2020, there were 27691 bicaval OHT, 13836 biatrial OHT, 1271 total OHT, and 51 HHT with sufficient follow-up. Survival was analyzed using restricted mean survival time (RMST) through 4 years as the outcome. In the first 4 years after transplant, compared with HHT, differences in RMST were 0.1 years (99% CI: -0.4 to 0.5 years) for bicaval OHT, 0.0 years (99% CI: -0.4 to 0.5 years) for biatrial OHT, and 0.0 years (99% CI: -0.5 to 0.4 years) for total OHT. In this cohort, survival was indistinguishable between HHT and OHT recipients in the first four years. Thus, HHT might be a viable alternative to durable mechanical circulatory assist particularly with size mismatched grafts or for patients with refractory pulmonary hypertension.

The effects of increased donor support time from organ donation referral to donor procurement on heart transplant recipient survival.

INTRODUCTION: Given the known deleterious cardiac effects of brain death (BD) physiology, we hypothesized that time from cardiac donation referral to procurement (donor support time [DST]), would negatively impact cardiac transplant recipient survival. METHODS: The United Network for Organ Sharing database was queried from 2007 to 2018, identifying 22,593 donor hearts for analysis. Multivariate logistic models for 30-day and 1-year survival, as well as Cox models for overall survival and posttransplant rejection, were used to assess adjusted outcomes. RESULTS: median DST was 3 days (interquartile range: 2-5 days). Ischemic time; distance between donor and recipient hospitals; and recipient age, creatinine, waitlist time, and length of stay were adjusted predictors of survival and rejection. DST was not associated with either outcome in aggregate; however, differential association by donor race was identified, with DST in any race recipient associated with 4% higher odds of 1-year mortality (p = .001; p value for interaction .005) but only a trend towards worse overall mortality (p = .064; p value for interaction .046). CONCLUSION: Thus, duration of exposure to BD physiology may have a differential impact on recipient outcomes based on donor race, suggesting that additional research is needed on donor immunologic, socioeconomic, and healthcare access factors that may impact cardiac transplant recipient outcomes.

Admission Society for Cardiovascular Angiography and Intervention shock stage stratifies post-discharge mortality risk in cardiac intensive care unit patients.

BACKGROUND: The five-stage Society for Cardiovascular Angiography and Intervention (SCAI) cardiogenic shock classification scheme can stratify hospital mortality risk in patients admitted to the cardiac intensive care unit (CICU). We sought to evaluate the SCAI shock classification for prediction of post-discharge mortality in CICU survivors. METHODS: We retrospectively analyzed hospital survivors admitted to a single CICU between 2007 and 2015. SCAI CS stages A through E were classified using CICU admission data using a previously published algorithm. All-cause post-discharge mortality was compared across SCAI stages using Kaplan-Meier analysis and Cox proportional hazards models. RESULTS: Among 9096 unique hospital survivors, 43.2% had acute coronary syndrome (ACS), 44.6% had heart failure (HF), and 8.7% had cardiac arrest (CA) on admission. The proportion of patients in each SCAI shock stage was: A, 49.1%; B, 30.6%; C, 15.2; D/E 5.2%. Kaplan-Meier survival at 5 years in each SCAI shock stage was: A, 88.2%; B, 81.6%; C, 76.7%; D/E, 71.7% (P < .001 by log-rank). Each higher SCAI shock stage was associated with increased adjusted post-discharge mortality compared to SCAI shock stage A (all P < .001); results were consistent among patients with ACS or HF. Late hemodynamic deterioration after 24 hours, but not an admission diagnosis of CA, was associated with higher post-discharge mortality. CONCLUSIONS: The SCAI shock classification assessed at the time of CICU admission was predictive of post-discharge mortality risk among hospital survivors, although an admission diagnosis of CA was not. The SCAI shock classification can be used for post-discharge mortality risk stratification.