Incidence of temporary mechanical circulatory support before heart transplantation and impact on post-transplant outcomes

International Society for Heart and Lung Transplantation Guidelines for the Evaluation and Care of Cardiac Transplant Candidates-2024

The "International Society for Heart and Lung Transplantation Guidelines for the Evaluation and Care of Cardiac Transplant Candidates-2024" updates and replaces the "Listing Criteria for Heart Transplantation: International Society for Heart and Lung Transplantation Guidelines for the Care of Cardiac Transplant Candidates-2006" and the "2016 International Society for Heart Lung Transplantation Listing Criteria for Heart Transplantation: A 10-year Update." The document aims to provide tools to help integrate the numerous variables involved in evaluating patients for transplantation, emphasizing updating the collaborative treatment while waiting for a transplant. There have been significant practice-changing developments in the care of heart transplant recipients since the publication of the International Society for Heart and Lung Transplantation (ISHLT) guidelines in 2006 and the 10-year update in 2016. The changes pertain to 3 aspects of heart transplantation: (1) patient selection criteria, (2) care of selected patient populations, and (3) durable mechanical support. To address these issues, 3 task forces were assembled. Each task force was cochaired by a pediatric heart transplant physician with the specific mandate to highlight issues unique to the pediatric heart transplant population and ensure their adequate representation. This guideline was harmonized with other ISHLT guidelines published through November 2023. The 2024 ISHLT guidelines for the evaluation and care of cardiac transplant candidates provide recommendations based on contemporary scientific evidence and patient management flow diagrams. The American College of Cardiology and American Heart Association modular knowledge chunk format has been implemented, allowing guideline information to be grouped into discrete packages (or modules) of information on a disease-specific topic or management issue. Aiming to improve the quality of care for heart transplant candidates, the recommendations present an evidence-based approach.

Intraoperative Use of Intra-Aortic Balloon Pump to Generate Pulsatile Flow During Heart Transplantation: A Single-Center Experience

The physiologic impact of pulsatile flow (PF) on end-organ perfusion during cardiopulmonary bypass (CPB) is controversial. Using an intra-aortic balloon pump (IABP) to maintain PF during CPB for patients undergoing heart transplantation (HT) may impact end-organ perfusion, with implications for postoperative outcomes. A single-center retrospective study of 76 patients bridged to HT with IABP was conducted between January 2018 and December 2022. Beginning in May 2022, patients received IABP-generated PF during CPB at an internal rate of 80 beats/minute. Fifty-eight patients underwent HT with the IABP turned off (IABP-Off), whereas 18 patients underwent HT with IABP-generated PF (IABP-On). The unmatched IABP-On group experienced shorter organ ischemia times (180 vs . 203 minutes, p = 0.015) and CPB times (104 vs . 116 minutes, p = 0.022). The cohort was propensity matched according to age, organ ischemia time, and CPB time. Elevations in postoperative lactates in the immediate (2.8 vs . 1.5, p = 0.062) and 24 hour (4.7 vs . 2.4, p = 0.084) postoperative periods trended toward significance in the matched IABP-Off group. There was no difference in postoperative vasoactive inotropic score (VIS), postoperative creatinine, or length of stay. This limited preliminary data suggest that maintaining counterpulsation to generate PF during CPB may improve end-organ perfusion in this patient population as suggested by lower postoperative lactate levels.

2024 AHA/ACC/ACS/ASNC/HRS/SCA/SCCT/SCMR/SVM Guideline for Perioperative Cardiovascular Management for Noncardiac Surgery: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The "2024 AHA/ACC/ACS/ASNC/HRS/SCA/SCCT/SCMR/SVM Guideline for Perioperative Cardiovascular Management for Noncardiac Surgery" provides recommendations to guide clinicians in the perioperative cardiovascular evaluation and management of adult patients undergoing noncardiac surgery.

METHODS

A comprehensive literature search was conducted from August 2022 to March 2023 to identify clinical studies, reviews, and other evidence conducted on human subjects that were published in English from MEDLINE (through PubMed), EMBASE, the Cochrane Library, the Agency for Healthcare Research and Quality, and other selected databases relevant to this guideline.

STRUCTURE

Recommendations from the "2014 ACC/AHA Guideline on Perioperative Cardiovascular Evaluation and Management of Patients Undergoing Noncardiac Surgery" have been updated with new evidence consolidated to guide clinicians; clinicians should be advised this guideline supersedes the previously published 2014 guideline. In addition, evidence-based management strategies, including pharmacological therapies, perioperative monitoring, and devices, for cardiovascular disease and associated medical conditions, have been developed.

Bridge to Transplantation: Policies Impact Practices

Since the development of the first heart allocation system in 1988 to the most recent heart allocation system in 2018, the road to heart transplantation has continued to evolve. Policies were shaped with advances in temporary and durable left ventricular assist devices as well as prioritization of patients based on degree of illness. Herein, we review the changes in the heart allocation system over the past several decades and the impact of practice patterns across the United States.

Veno-arterial ECMO ventricular assistance as a direct bridge to heart transplant: A single center experience in a low-middle income country

INTRODUCTION

The use of veno-arterial extracorporeal membrane oxygenation (VA-ECMO) as a direct bridge to heart transplantation (BTT) is not common in adults worldwide. BTT with ECMO is associated with increased early/mid-term mortality compared with other interventions. In low- and middle-income countries (LMIC), where no other type of short-term mechanical circulatory support is available, its use is widespread and increasingly used as rescue therapy in patients with cardiogenic shock (CS) as a direct bridge to heart transplantation (HT).

OBJECTIVE

To assess the outcomes of adult patients using VA-ECMO as a direct BTT in an LMIC and compare them with international registries.

METHODS

We conducted a single-center study analyzing consecutive adult patients requiring VA-ECMO as BTT due to refractory CS or cardiac arrest (CA) in a cardiovascular center in Argentina between January 2014 and December 2022. Survival and adverse clinical events after VA-ECMO implantation were evaluated.

RESULTS

Of 86 VA-ECMO, 22 (25.5%) were implanted as initial BTT strategy, and 52.1% of them underwent HT. Mean age was 46 years (SD 12); 59% were male. ECMO was indicated in 81% for CS, and the most common underlying condition was coronary artery disease (31.8%). Overall, in-hospital mortality for VA-ECMO as BTT was 50%. Survival to discharge was 83% in those who underwent HT and 10% in those who did not, p < .001. In those who did not undergo HT, the main cause of death was hemorrhagic complications (44%), followed by thrombotic complications (33%). The median duration of VA-ECMO was 6 days (IQR 3-16). There were no differences in the number of days on ECMO between those who received a transplant and those who did not. In the Spanish registry, in-hospital survival after HT was 66.7%; the United Network of Organ Sharing registry estimated post-transplant survival at 73.1% ± 4.4%, and in the French national registry 1-year posttransplant survival was 70% in the VA-ECMO group.

CONCLUSIONS

In adult patients with cardiogenic shock, VA-ECMO as a direct BTT allowed successful HT in half of the patients. HT provided a survival benefit in listed patients on VA-ECMO. We present a single center experience with results comparable to those of international registries.

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.

Increasing waiting times for status 2 patients in new United Network for Organ Sharing allocation system: Impact on waitlist and posttransplant outcomes

OBJECTIVE

Since the heart transplant allocation policy change in 2018, there has been an increase in temporary mechanical circulatory support for Status 2 patients. We sought to examine the temporal pattern of waitlist and posttransplant outcomes for Status 2 patients.

METHODS

Adult patients in the United Network for Organ Sharing registry who were listed as Status 2 from January 2019 to June 2022 were included. Temporal trends in waitlist time, waitlist events, and posttransplant outcomes were assessed. Probability of transplant or death after being listed was compared over time. Multivariable regression was performed to identify risk factors for mortality after transplant.

RESULTS

A total of 6310 patients were included. From 2019 to 2022, the number of Status 2 patients listed increased from 4.2 to 5.9 per day. Microaxial ventricular assist devices at Status 2 listing increased over time (P < .001). During the study period, median waitlist time (18 days vs 23 days, P < .001) as well as Status 2 days (8 days vs 12 days, P < .001) increased. Waitlist mortality remained stable (5.5%); however, probability of transplant within 90 days of Status 2 listing progressively declined (P < .001). Finally, longer waitlist duration was independently associated with 30-day posttransplant mortality (odds ratio, 1.01; 95% confidence interval, 1.00-1.01, P = .02).

CONCLUSIONS

Since the allocation policy change there has been a steady rise in the number of patients listed for Status 2. This has led to increasing waitlist times and lower probability of transplantation for Status 2 patients, which may have negative consequences for posttransplant outcomes.

Heart Transplantation

Heart transplantation (HTx) remains the last therapeutic resort for patients with advanced heart failure. The present work is a clinically focused review discussing current issues in heart transplantation. Several factors have been associated with the outcome of HTx, such as ABO and HLA compatibility, graft size, ischemic time, age, infections, and the cause of death, as well as imaging and laboratory tests. In 2018, UNOS changed the organ allocation policy for HTx. The aim of this change was to prioritize patients with a more severe clinical condition resulting in a reduction in mortality of people on the waiting list. Advanced heart failure and resistant angina are among the main indications of HTx, whereas active infection, peripheral vascular disease, malignancies, and increased body mass index (BMI) are important contraindications. The main complications of HTx include graft rejection, graft angiopathy, primary graft failure, infection, neoplasms, and retransplantation. Recent advances in the field of HTx include the first two porcine-to-human xenotransplantations, the inclusion of hepatitis C donors, donation after circulatory death, novel monitoring for acute cellular rejection and antibody-mediated rejection, and advances in donor heart preservation and transportation. Lastly, novel immunosuppression therapies such as daratumumab, belatacept, IL 6 directed therapy, and IgG endopeptidase have shown promising results.

Effect of the UNOS policy change on rates of rejection, infection, and hospital readmission following heart transplantation

BACKGROUND

The 2018 adult heart allocation policy sought to improve waitlist risk stratification, reduce waitlist mortality, and increase organ access. This system prioritized patients at greatest risk for waitlist mortality, especially individuals requiring temporary mechanical circulatory support (tMCS). Posttransplant complications are significantly higher in patients on tMCS before transplantation, and early posttransplant complications impact long-term mortality. We sought to determine if policy change affected early posttransplant complication rates of rejection, infection, and hospitalization.

METHODS

We included all adult, heart-only, single-organ heart transplant recipients from the UNOS registry with pre-policy (PRE) individuals transplanted between November 1, 2016, and October 31, 2017, and post-policy (POST) between November 1, 2018, and October 31, 2019. We used a multivariable logistic regression analysis to assess the effect of policy change on posttransplant rejection, infection, and hospitalization. Two COVID-19 eras (2019-2020, 2020-2021) were included in our analysis.

RESULTS

The majority of baseline characteristics were comparable between PRE and POST era recipients. The odds of treated rejection (p = 0.8), hospitalization (p = 0.69), and hospitalization due to rejection (p = 0.76) and infection (p = 0.66) were similar between PRE and POST eras; there was a trend towards reduced odds of rejection (p = 0.08). In both COVID eras, there was a clear reduction in rejection and treated rejection with no effect on hospitalization for rejection or infection. Odds of all-cause hospitalization was increased in both COVID eras.

CONCLUSIONS

The UNOS policy change improves access to heart transplantation for higher acuity patients without increasing early posttransplant rates of treated rejection or hospitalization for rejection or infection, factors which portend risk for long-term posttransplant mortality.

Role of acute mechanical circulatory support devices in cardiogenic shock

Cardiogenic shock is a state of low cardiac output that is associated with significant morbidity and mortality. A considerable proportion of patients with cardiogenic shock respond poorly to medical management and require acute mechanical circulatory support (AMCS) devices to improve tissue perfusion as well as to support the heart. In the last two decades, many new AMCS devices have been introduced to support the right, left, and both ventricles. All these devices vary in terms of the support they provide to the body and heart, mechanism of functioning, method of insertion, and adverse events. In this review, we compare and contrast the available percutaneous and surgically placed AMCS devices used in cardiogenic shock and discuss the associated clinical and hemodynamic data to make a conscious decision about choosing a device.

Outcomes after heart transplantation in patients who have undergone a bridge-to-bridge strategy

Objectives

We compared posttransplant outcomes between patients bridged from temporary mechanical circulatory support to durable left ventricular assist device before transplant (bridge-to-bridge [BTB] strategy) and patients bridged from temporary mechanical circulatory support directly to transplant (bridge-to-transplant [BTT] strategy).

Methods

We identified adult heart transplant recipients in the Organ Procurement and Transplantation Network database between 2005 and 2020 who were supported with extracorporeal membrane oxygenation, intra-aortic balloon pump, or temporary ventricular assist device as a BTB or BTT strategy. Kaplan-Meier survival analysis and Cox regressions were used to assess 1-year, 5-year, and 10-year survival. Posttransplant length of stay and complications were compared as secondary outcomes.

Results

In total, 201 extracorporeal membrane oxygenation (61 BTB, 140 BTT), 1385 intra-aortic balloon pump (460 BTB, 925 BTT), and 234 temporary ventricular assist device (75 BTB, 159 BTT) patients were identified. For patients supported with extracorporeal membrane oxygenation, intra-aortic balloon pump, or temporary ventricular assist device, there were no differences in survival between BTB and BTT at 1 and 5 years posttransplant, as well as 10 years posttransplant even after adjusting for baseline characteristics. The extracorporeal membrane oxygenation BTB group had greater rates of acute rejection (32.8% vs 13.6%; P = .002) and lower rates of dialysis (1.6% vs 21.4%; P < .001). For intra-aortic balloon pump and temporary ventricular assist device patients, there were no differences in posttransplant length of stay, acute rejection, airway compromise, stroke, dialysis, or pacemaker insertion between BTB and BTT recipients.

Conclusions

BTB patients have similar short- and midterm posttransplant survival as BTT patients. Future studies should continue to investigate the tradeoff between prolonged temporary mechanical circulatory support versus transitioning to durable mechanical circulatory support.

Utility of the IMPACT score for predicting heart transplant mortality. Analysis on a contemporary cohort of the Spanish Heart Transplant Registry

INTRODUCTION AND OBJECTIVES

The Index for Mortality Prediction After Cardiac Transplantation (IMPACT) score was derived and validated as a predictor of mortality after heart transplantation (HT). The primary objective of this work is to externally validate the IMPACT score in a contemporary Spanish cohort.

METHODS

Spanish Heart Transplant Registry data were used to identify adult (>16 years) HT patients between January 2000 and December 2015. Retransplantation, multiorgan transplantation and patients in whom at least one of the variables required to calculate the IMPACT score was missing were excluded from the analysis (N = 2,810).

RESULTS

Median value of the IMPACT score was 5 points (IQR: 3, 8). Overall 1-year survival rate was 79.1%. Kaplan-Meier 1-year survival rates by IMPACT score categories (0-2, 3-5, 6-9, 10-14, ≥ 15) were 84.4%, 81.5%, 79.3%, 77.3% and 58.5% respectively (Log-Rank test: p<0.001). Performance analysis showed a good calibration (Hosmer-Lemeshow chi-square for one year was 7.56; p = 0.47) and poor discrimination ability (AUC-ROC 0.59) of the IMPACT score as a predictive model.

CONCLUSIONS

In a contemporary Spanish cohort, the IMPACT score failed to accurately predict the risk of death after HT. This article is protected by copyright. All rights reserved.

Post Heart Transplantation Outcomes of Patients Supported on Biventricular Mechanical Support

With the implementation of the new heart transplant (HT) allocation system, patients requiring biventricular support systems have the highest priority, a shorter waitlist time, and a higher frequency of HT. However, the short-term and long-term outcomes of such patients are often disputed. Hence, we examined the outcomes of these patients who underwent HT before change in allocation scheme. Additionally, we compared post-HT outcomes of extracorporeal membrane oxygenation (ECMO) with other nondischargeable biventricular (BiVAD) supported patients. We identified adult ECMO or BiVAD supported HT recipients between 2000 and 2018 in the Scientific Registry of Transplant Recipients database. We compared survival with the Kaplan-Meier method. Using overlap propensity score weighting, we constructed Cox proportional hazards regression models to determine the risk-adjusted influence of BiVAD versus ECMO on survival. Of the 730 patients HT recipients; 528 (72.3%) and 202 (27.7%) were bridged with BiVAD and ECMO, respectively. For BiVAD versus ECMO patients, the 30-day, 1-year, 3-year, and 5-year mortality rates were 8.0% versus 14.4%, 16.3% versus 21.3%, 22.4% versus 25.3%, and 26.3% versus 25.7%, respectively. Risk-adjusted post-HT survival of BiVAD and ECMO patients at 30-day (HR 1.24 [95% CI, 0.68-2.27]; P = 0.4863), 1-year (HR 1.29 [95% CI, 0.80-2.09]; P = 0.3009), 3-year (HR 1.27 [95% CI, 0.83-1.94]; P = 0.2801), and 5-year (HR 1.35, 95% CI, 0.90-2.05; P = 0.1501) were similar. Around three-fourth of the ECMO or BiVAD supported patients were alive at 5-years post-HT. The short-term and long-term post-HT survivals of groups were comparable.

2022 AHA/ACC/HFSA Guideline for the Management of Heart Failure: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The "2022 AHA/ACC/HFSA Guideline for the Management of Heart Failure" replaces the "2013 ACCF/AHA Guideline for the Management of Heart Failure" and the "2017 ACC/AHA/HFSA Focused Update of the 2013 ACCF/AHA Guideline for the Management of Heart Failure." The 2022 guideline is intended to provide patient-centric recommendations for clinicians to prevent, diagnose, and manage patients with heart failure.

METHODS

A comprehensive literature search was conducted from May 2020 to December 2020, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from MEDLINE (PubMed), EMBASE, the Cochrane Collaboration, the Agency for Healthcare Research and Quality, and other relevant databases. Additional relevant clinical trials and research studies, published through September 2021, were also considered. This guideline was harmonized with other American Heart Association/American College of Cardiology guidelines published through December 2021. Structure: Heart failure remains a leading cause of morbidity and mortality globally. The 2022 heart failure guideline provides recommendations based on contemporary evidence for the treatment of these patients. The recommendations present an evidence-based approach to managing patients with heart failure, with the intent to improve quality of care and align with patients' interests. Many recommendations from the earlier heart failure guidelines have been updated with new evidence, and new recommendations have been created when supported by published data. Value statements are provided for certain treatments with high-quality published economic analyses.

2022 AHA/ACC/HFSA Guideline for the Management of Heart Failure

AIM

The "2022 AHA/ACC/HFSA Guideline for the Management of Heart Failure" replaces the "2013 ACCF/AHA Guideline for the Management of Heart Failure" and the "2017 ACC/AHA/HFSA Focused Update of the 2013 ACCF/AHA Guideline for the Management of Heart Failure." The 2022 guideline is intended to provide patient-centric recommendations for clinicians to prevent, diagnose, and manage patients with heart failure.

METHODS

A comprehensive literature search was conducted from May 2020 to December 2020, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from MEDLINE (PubMed), EMBASE, the Cochrane Collaboration, the Agency for Healthcare Research and Quality, and other relevant databases. Additional relevant clinical trials and research studies, published through September 2021, were also considered. This guideline was harmonized with other American Heart Association/American College of Cardiology guidelines published through December 2021.

STRUCTURE

Heart failure remains a leading cause of morbidity and mortality globally. The 2022 heart failure guideline provides recommendations based on contemporary evidence for the treatment of these patients. The recommendations present an evidence-based approach to managing patients with heart failure, with the intent to improve quality of care and align with patients' interests. Many recommendations from the earlier heart failure guidelines have been updated with new evidence, and new recommendations have been created when supported by published data. Value statements are provided for certain treatments with high-quality published economic analyses.

Radiology of Intra-Aortic Balloon Pump Catheters

Radiographs play an important role in ascertaining appropriate placement of the intra-aortic balloon pump catheter. This imaging essay highlights correct and incorrect positioning of these catheters, with emphasis on the variability of radiopaque markers used with different catheter models and on axillary versus femoral catheter placement routes. Keywords: Conventional Radiography, CT, Percutaneous, Cardiac, Vascular, Aorta, Anatomy, Cardiac Assist Devices, Catheters © RSNA, 2022.

Recent Changes in Durable Left Ventricular Assist Device Bridging to Heart Transplantation

This study evaluates the impact of the recent United Network for Organ Sharing (UNOS) allocation policy change on outcomes of patients bridged with durable left ventricular assist devices (LVADs) to orthotopic heart transplantation (OHT). Adults bridged to OHT with durable LVADs between 2010 and 2019 were included. Patients were stratified based on the temporal relationship of their OHT to the UNOS policy change on October 18, 2018. The primary outcome was early post-OHT survival. In total, 9,628 OHTs were bridged with durable LVADs, including 701 (7.3%) under the new policy. Of all OHTs performed during the study period, the proportion occurring following durable LVAD bridging decreased from 45% to 34% (p < 0.001). The more recent cohort was higher risk, including more extracorporeal membrane oxygenation bridging (2.6% vs. 0.3%, p < 0.001), more mechanical right ventricular support (9.7% vs. 1.4%, p < 0.001), greater pretransplant ICU admission (22.8% vs. 8.7%, p < 0.001) more need for total functional assistance (62.8% vs. 53.0%, p < 0.001), older donor age (33.3 vs. 31.7 years, p < 0.001), and longer ischemic times (3.38 vs. 3.13 hours, p < 0.001). Despite this, early post-OHT survival was comparable at 30 days (96.1% vs. 96.0%, p = 0.89), 90 days (93.7% vs. 94.0%, p = 0.76), and 6 months (91.0% vs. 93.0%, p = 0.96), findings that persisted after risk-adjustment. In this early analysis, OHT following bridging with durable LVADs is performed less frequently and in higher risk recipients under the new allocation policy. Despite this, short-term posttransplant outcomes appear to be unaffected in this patient cohort in the current era.

Impact of Temporary Percutaneous Mechanical Circulatory Support Before Transplantation in the 2018 Heart Allocation System

OBJECTIVES

This analysis sought to investigate the waitlist and post-transplant outcomes of individuals bridged to transplantation by using temporary percutaneous endovascular mechanical circulatory support (tMCS) through a status 2 designation (cardiogenic shock and exception).

BACKGROUND

The 2018 donor heart allocation policy change granted a status 2 designation to patients supported with tMCS.

METHODS

Adult patients in the United Network for Organ Sharing registry after October 18, 2018 who received a status 2 designation for tMCS were included and grouped by their status 2 criteria: cardiogenic shock with hemodynamic criteria (CS-HD), cardiogenic shock without hemodynamic criteria before tMCS (CS-woHD), and exception. Baseline characteristics, waitlist events (death and delisting), and post-transplant outcomes were compared.

RESULTS

A total of 2,279 patients met inclusion criteria: 68.6% (n = 1,564) with CS-HD, 3.2% (n = 73) with CS-woHD, and 28.2% (n = 642) with exceptions. A total of 64.2% of patients underwent heart transplantation within 14 days of status 2 listing or upgrade, and 1.9% died or were delisted for worsening clinical condition. Among the 35.8% who did not undergo transplantation following 14 days, only 2.8% went on to receive a left ventricular assist device (LVAD). The 30-day transplantation likelihood was similar among groups: 80.1% for the CS-HD group vs 79.7% for the exception group vs 73.3% for the CS-woHD group; P = 0.31. However, patients who met criteria for CS-woHD had 2.3-fold greater risk of death or delisting (95% CI: 1.10-4.75; P = 0.03) compared with CS-HD patients after multivariable adjustment. Pre-tMCS hemodynamics were not associated with adverse waitlist events.

CONCLUSIONS

The use of tMCS is an efficient, safe, and effective strategy as a bridge to transplantation; however, patients with CS-woHD may represent a high-risk cohort. Transition to a durable LVAD was a rare event in this group.

Use of Extracorporeal Membrane Oxygenation as Bridge to Replacement Therapies in Cardiogenic Shock: Insights From the Extracorporeal Life Support Organization

BACKGROUND

There has been increasing use of extracorporeal membrane oxygenation (ECMO) as bridge to heart transplant (orthotopic heart transplant [OHT]) or left ventricular assist device (LVAD) over the last decade. We aimed to provide insights on the population, outcomes, and predictors for the selection of each therapy.

METHODS

Using the Extracorporeal Life Support Organization Registry between 2010 and 2019, we compared in-hospital mortality and length of stay, predictors of OHT versus LVAD, and predictors of in-hospital mortality for patients with cardiogenic shock that were bridged with ECMO to OHT or LVAD. One hundred sixty-seven patients underwent LVAD versus 234 patients who underwent OHT.

RESULTS

The overall use of ECMO has increased from 1.7% in 2010 to 22.2% in 2019. Mortality was similar between groups (LVAD: 28.7% versus OHT: 29.1%) while length of stay was longer for OHT (LVAD: 49.6 versus OHT: 59.5 days, P=0.05). Factors associated with OHT included prior transplant (odds ratio [OR]=31.26 [CI, 3.84-780.5]), use of a temporary pacemaker (OR=6.5 [CI, 1.39-50.15]), and increased use of inotropes on ECMO (OR=3.77 [CI, 1.39-11.07]), whereas LVAD use was associated with weight (OR=0.98 [CI, 0.97-0.99]), cardiogenic shock presentation (OR=0.40 [CI, 0.21-0.78]), previous LVAD (OR=0.01 [CI, 0.0001-0.22]), respiratory failure (OR=0.28 [CI, 0.11-0.70]), and milrinone infusion (OR=0.32 [CI, 0.15-0.67]). Older age (OR=1.07 [CI, 1.02-1.12]), cannulation bleeding (OR=26.1 [CI, 4.32-221.3]), and surgical bleeding (OR=6.7 [CI, 1.26-39.9]) in patients receiving LVAD and respiratory failure (OR=5 [CI, 1.17-23.1]) and continuous renal replacement therapy (OR=3.82 [CI, 1.28-11.9]) in patients receiving OHT were associated with increased mortality.

CONCLUSIONS

ECMO use as a bridge to advanced therapies has increased over time, with more patients undergoing LVAD than OHT. Mortality was equal between the 2 groups while length of stay was longer for OHT.

Impact of UNOS allocation policy changes on utilization and outcomes of patients bridged to heart transplant with intra-aortic balloon pump

OBJECTIVE

Intra-aortic balloon pump (IABP) support may improve the hemodynamic profiles of patients in cardiogenic shock and bridge patients to heart transplant. In 2018, the United Network for Organ Sharing (UNOS) introduced new heart allocation criteria that increased the waitlist status of patients with IABPs to Status 2. This study assesses the impact of this change on IABP use and outcomes of patients with IABPs.

METHODS

We queried the UNOS database for first adult heart transplant candidates with IABPs listed or transplanted before and after the UNOS policy changes (October 18, 2016-October 17, 2018, or October 18, 2018-September 4, 2020). We compared post-transplant survival and waitlist outcomes using Kaplan-Meier and Fine-Gray analyses.

RESULTS

Two thousand three hundred fifty-eight patients met inclusion criteria. Utilization of IABPs for hemodynamic support increased by 338% in the two years after the policy change. Patients with IABPs listed after the policy change were more likely to receive a transplant and were transplanted more quickly (p < .001). Posttransplant survival was comparable before and after the policy change (p = .056), but non-transplanted patients were more likely to be delisted post-policy change (p < .001).

CONCLUSION

The UNOS allocation criteria have benefited patients bridged with an IABP, given the higher transplant rate and shorter time to transplant.

Intra-aortic balloon pump for acute-on-chronic heart failure complicated by cardiogenic shock

The Intra-aortic balloon pump (IABP) is widely implanted as temporary mechanical circulatory support for cardiogenic shock (CS). However, its use is declining following the results of the IABP-SHOCK II trial, which failed to show a clinical benefit of IABP in acute coronary syndrome (ACS) related CS. Acute-on-chronic heart failure has become an increasingly recognized, distinct etiology of CS (HF-CS). The pathophysiology of HF-CS differs from ACS-CS, as it typically represents the progression from a state of congestion (with relatively preserved cardiac output) to a low output state with hypoperfusion. The IABP is a "volume displacement pump" that promotes forward flow from a high-capacitance reservoir to low-capacitance vessels, improving peripheral perfusion and decreasing left ventricular afterload in the setting of high filling pressures. The IABP can improve ventricular-vascular coupling and, therefore, myocardial energetics. Additionally, many HF-CS patients are candidates for cardiac replacement therapies (left ventricular assist device or heart transplantation), and, therefore, may benefit from a "bridge" strategy that stabilizes the hemodynamics and end-organ function in preparation for more durable therapies. Notably, the new United Network for Organ Sharing donor heart allocation system has recently prioritized patients on IABP support. This review describes the role of IABP for the treatment of HF-CS. It also briefly discusses new strategies for vascular access as well as a fully implantable versions for a longer duration of support.

Imaging for Temporary Mechanical Circulatory Support Devices

Heart failure is an important cause of mortality and morbidity in the world. Changes in organ allocation for solid thoracic (lung and heart) transplantation has increased the number of patients on mechanical circulatory support. Temporary mechanical support devices include devices tht support the circulation directly or indirectly such as extracorporeal membrane oxygenation (ECMO) and temporary support for right-sided failure, left-sided failure or biventricular failure. Most often, these devices are placed percutaneously and require either guidance with echocardiography, continuous radiography (fluoroscopy) or both. Furthermore, these devices need imaging in the intensive care unit to confirm continued accurate placement. This review contains the imaging views and nuances of the temporary assist devices (including ECMO) at the time of placement and the complications that can be associated with each individual device.

30-Year Trends in Graft Survival After Heart Transplant: Modeled Analyses of a Transplant Registry

BACKGROUND

Heart failure is an epidemic in the United States, and transplantation remains the most definitive therapy. We describe multi-decade trends in post-transplant graft survival, adjusted for concurrent changes in the population, over the 30 years antecedent to the most recent heart allocation policy change.

METHODS

Scientific Registry of Transplant Recipients data were used to identify all primary adult heart recipients 1989 through 2017. We described temporal changes in population characteristics (recipient/donor demographics and comorbidities, pretransplant interventions, clinical transplant measures, and providers). The primary outcome was graft survival, defined as freedom from all-cause death and graft failure, within 6 months post-transplant. Modified Poisson logistic regression estimated relative changes in risk of outcomes compared to 1989, with and without adjustment for changing population characteristics. We identified risk factors, quantified by associated risk ratios.

RESULTS

Among 56,488 primary adult heart recipients, we observed 5,529 (9.8%) all-cause deaths and 1,933 (3.4%) graft failure events within 6 months post-transplant. Prevalence of known recipient risk factors increased over time. Unadjusted modeling demonstrated a significant 30-year improvement in graft survival, averaging 2.6% (95%CI:2.4-2.9%) per year (p-for-trend<0.001). After adjusting for population changes, the 30-year trend remained significant and graft survival improved on average 3.0% (95%CI:2.6-3.3%) yearly. Regression modeling identified multiple predictors of graft survival. Modeling two additional outcomes of 6-month mortality and 6-month graft failure produced like results.

CONCLUSIONS

Short-term graft survival after heart transplantation has improved significantly leading up to the 2018 heart allocation policy change, despite concurrent increase in prevalence of higher risk population characteristics.

Changes in waitlist and posttransplant outcomes in patients with adult congenital heart disease after the new heart transplant allocation system

OBJECTIVE

In 2018, the United Network for Organ Sharing (UNOS) introduced new criteria for heart allocation. This study sought to assess the impact of this change on waitlist and posttransplant outcomes in adult congenital heart disease (ACHD) recipients.

METHODS

Between January 2010 and March 2020, we extracted first heart transplant ACHD patients listed from the UNOS database. We compared waitlist and post-transplant outcomes before and after the policy change.

RESULTS

A total of 1206 patients were listed, 951 under the old policy and 255 under the new policy. Prior to transplant, recipients under the new policy era were more likely to be treated with extracorporeal membrane oxygenation (P = .018), and have intra-aortic balloon pumps (P < .001), and less likely to have left ventricular assist devices (P = .027).Compared to patients waitlisted in the pre-policy change era, those waitlisted in the post policy change era were more likely to receive transplants (P = .001) with no significant difference in waiting list mortality (P = .267) or delisting (P = .915). There was no difference in 1-year survival post-transplant between the groups (P = .791).

CONCLUSION

The new policy altered the heart transplant cohort in the ACHD group, allowing them to receive transplants earlier with no changes in early outcomes after heart transplantation.

Accuracy of administrative database estimates of national surgical volume: Solid organ transplantation in the National Inpatient Sample

BACKGROUND

Little is known about the accuracy of procedural coding in the National Inpatient Sample, in part because it is challenging to validate population-level estimates.

METHODS

We evaluated the accuracy of the National Inpatient Sample by comparing estimates of solid organ transplantation to known national transplant volumes from the Organ Procurement and Transplant Network.

RESULTS

The mean deviation of National Inpatient Sample point estimates from true transplant volume for the study period was 17.5 ± 20.8%. The mean deviation of point estimates from 2005 to 2011 was 26.4 ± 22.8% compared to 4.9 ± 6.3% from 2012 to 2016 (P < .001).

CONCLUSIONS

Although future National Inpatient Sample transplantation research may be limited by the inability to subgroup procedures by donor type, surgical procedure coding of solid organ transplantation within the National Inpatient Sample appears to be accurate and reliable for generating national estimates, particularly after the National Inpatient Sample redesign in 2012.

Percutaneous Axillary Intra-aortic Balloon Pump Insertion Technique as Bridge to Advanced Heart Failure Therapy

In patients with advanced heart failure (HF), temporary mechanical circulator support (TMCS) is used to improve hemodynamics, via left ventricular unloading, and end-organ function as a bridge to definitive therapy. While listed for cardiac transplantation, use of TMCS may be prolonged, preventing adequate mobility. Here, we describe the technique for placement of a percutaneous axillary intra-aortic balloon pump (IABP) using single-site arterial access to facilitate ambulation and subsequent safe removal without surgery or a closure device. Retrospective review of the experience with this approach at a single institution between September 2017 and February 2020 documented feasibility and safety. Baseline demographics, hemodynamic data, and clinical outcomes were collected. Thirty-eight patients had a total of 56 IABPs placed. There were no significant access site or cerebrovascular complications. One fifth of IABPs (21.4%) had balloon failure or migration, requiring placement of a new device, though no patients had significant complications from balloon failure. The majority (81.6%) of patients in the cohort on axillary IABP support were ambulatory and ultimately received the intended therapy (63.2% transplant, 13.2% durable left ventricular assist device, 5.3% other cardiac surgery). Percutaneous, axillary IABP is feasible and associated with an acceptable complication rate as a bridge to definitive therapy.

Mechanical Circulatory Support Prior to Heart Transplantation Predicts Early Post-Operative Stroke

BACKGROUND

Mechanical circulatory support (MCS) devices are often deployed to treat patients with refractory cardiogenic shock, rapid deterioration of heart failure, and inotrope-dependent patients. Stroke is a common complication of MCS therapy. This study assesses the risk of stroke during the early post-heart transplantation (HT) period (days from successful HT to discharge or death) in patients who received MCS therapy leading to HT.

METHODS

Data were derived from the United Organ Sharing (UNOS) database. MCS modalities studied include left ventricular assist devices (LVAD), right ventricular assist devices (RVAD), biventricular ventricular assist devices (BiVAD), and extra-corporeal membrane oxygenation (ECMO). A multiple logistic regression model was used to determine the risk of stroke during the early post-HT period associated in patients treated with MCS leading to HT.

RESULTS

Between 1988 and 2014, 10,258 patients received MCS therapy leading to HT. Of these, 160 patients (1.96%) developed stroke during the early post-HT period. Multiple regression analysis showed that MCS modalities and associated odds ratios for early post-HT stroke and associated 95% confidence intervals were as follows: LVAD (1.44, 0.70-2.94), RVAD (2.89, 1.03-8.05, BiVAD (3.24, 1.15-9.10), ECMO (2.27 (1.17-4.40), and any MCS (1.60 (1.20-2.12).

CONCLUSIONS

With the exception of left ventricular assist devices, use of MCS modalities leading to HT is significantly and independently associated with stroke during the early post-HT period.

Incidence and Clinical Significance of Hyperkalemia Following Heart Transplantation

BACKGROUND

Hyperkalemia (HK) is a life-threatening complication following solid organ transplantation, and patients often need potassium-chelating agents and deviations from standard posttransplant protocols. This is the first study to report the incidence and clinical impact of hyperkalemia following heart transplantation.

METHODS

We retrospectively included patients who underwent heart transplantation at our institution between April 2014 and December 2018. Patients with multiorgan transplantation were excluded. Clinical outcomes of patients who had serum potassium >5.5 mEq/L in the first year posttransplant (HK group) were compared to patients who did not have serum potassium >5.5 mEq/L in the first year posttransplant (non-HK group).

RESULTS

A total of 143 patients were included in this study. During the first year posttransplant, cumulative incidence of serum potassium >5.0, >5.5, and >6.0 mEq/L was 96%, 63%, and 24%, respectively. Fifty-five percent of patients required treatment with potassium-chelating agents. Sulfamethoxazole-trimethoprim was discontinued because of HK in 39% of patients. Overall survival of patients in the HK group (n = 89) was comparable to that of patients in the non-HK group (n = 54, 91% vs 98% at 1 year, P = .19), whereas infection-free survival was significantly lower in the HK group (34% vs 53% at 1 year, P = .010). Multivariate analysis revealed pretransplant renal dysfunction (odds ratio = 2.62; 95% confidence interval, 1.18-5.80; P = .018) and use of mechanical circulatory support (odds ratio = 2.90; 95% confidence interval, 1.08-7.76; P = .035) as significant predictors of posttransplant hyperkalemia.

CONCLUSIONS

The incidence of HK following heart transplantation was high, with more than half of patients requiring any therapeutic interventions, and HK was related to an increase in infection events.

An Analysis of Waitlist Inactivity Among Patients With Ventricular Assist Devices

BACKGROUND

Ventricular assist devices (VADs) are commonly used mechanical circulatory support for bridge to transplant therapy in end-stage heart failure; however, it is not understood how VADs influence incidence of waitlist inactive status. We sought to characterize and compare waitlist inactivity among patients with and without VADs.

METHODS

Using the Organ Procurement and Transplantation Network database, we investigated the VAD's impact on incidence and length of inactive periods for heart transplant candidates from 2005 through 2018. We compared median length of inactivity between patients with and without VADs and investigated inactivity risk with time-to-event regression models.

RESULTS

Among 46,441 heart transplant candidates, 32% (n = 14,636) had a VAD. Thirty-eight percent (n = 17,873) of all patients experienced inactivity, of which 42% (7538/17,873) had a VAD. Median inactivity length was 31 d for patients without VADs and 62 d for VAD patients (P < 0.0005). Multivariable analysis showed no significant difference in risk of inactivity for deteriorating conditions between patients with and without VADs after controlling for demographic and baseline clinical variables. A larger proportion of patients without VADs were inactive for deteriorating conditions than VAD patients (54%, n = 8242/15,221 versus 32%, n = 3583/11,086, P < 0.001). Ten percent (1155/11,086) of VAD patients' inactive periods were for VAD-related complications.

CONCLUSIONS

Although VAD patients were inactive longer and had an overall increased risk of any-cause inactivity, their risk of inactivity for deteriorating condition was not significantly different from patients without VADs. Furthermore, VAD patients had a smaller proportion of inactivity periods due to deteriorating conditions. Thus, VADs are protective from morbidity for waitlist patients.

Urgent desensitization in patients bridged to heart transplantation under extracorporeal membrane oxygenation support: A preliminary experience

Antihuman leukocyte antigen (HLA) antibodies restrict the access to cardiac allografts. Desensitization therapy is a major challenge in patients with cardiogenic shock waiting for urgent heart transplantation (HT). We retrospectively reviewed six patients (mean age of 37.5 years [16-70]) who underwent plasmapheresis (PP) under extracorporeal membrane oxygenation (ECMO) before transplant between January 2017 and September 2018. The average duration of follow-up was 25 months [20-32]. Mean fluorescence intensity (MFI) of HLA-specific antibodies was reported as follows: score 4 for MFI < 1000, score 6 for 1000 < MFI < 3000 and score 8 for MFI > 3000. The mean duration of ECMO support was 29 days [1-74] and 6.8 [1-29] PP sessions were performed per patient before transplant. The mean number of HLA-specific antibodies before HT was 9.6 for score 6 [4-13] and 5.8 for score 8 [1-12]. Four patients had major complications after transplantation (2 hemorrhagic shocks, 5 infectious events). Mean MFI reduction rate was 94% [79-100] for Class I and 44.2% for Class II [0-83]. Hospital survival was 100%, and early antibody-mediated rejection was diagnosed in one patient at 7 days after HT. Plasmapheresis under ECMO support was associated with favorable early outcomes in highly sensitized candidates for urgent heart transplantation.

Improved survival after heart transplantation in patients bridged with extracorporeal membrane oxygenation in the new allocation system

BACKGROUND

Historically, patients bridged on extracorporeal membrane oxygenation (ECMO) to heart transplantation (HT) have very high post-transplant mortality. In the new heart transplant allocation system, ECMO-supported patients have the highest priority for HT. However, data are lacking on the outcomes of these critically ill patients. We compared the waitlist and post-transplant outcomes of ECMO-supported patients in the new and old allocation systems.

METHODS

Adult patients supported by ECMO at the time of listing or transplantation who were registered in the United Network for Organ Sharing database between November 1, 2015 and September 30, 2019 were included. Clinical characteristics, outcomes in the waitlist, and post-transplant survival were compared between the old and new systems. Cox Proportional and subdistribution hazard regression models were used to evaluate the variables contributing to the post-transplant and waitlist outcomes RESULTS: A total of 296 ECMO-supported patients were listed for HT. Of these, 191 were distributed to the old system, and 105 were distributed to the new system. Patients listed in the new system had a higher cumulative incidence of HT (p < 0.001) and lower incidence of death or removal (p = 0.001) from the transplant list than patients listed in the old system. The 6-month survival after transplantation was 74.6% and 90.6% for the old- and new-era patients, respectively (p = 0.002). Among ECMO-supported patients, being listed or transplanted on the new system was independently associated with improved outcomes in the waitlist and after transplantation.

CONCLUSIONS

With the implementation of the new heart transplant allocation system, ECMO-supported patients have a shorter waitlist time, improved frequency of HT, and improved short-term post-transplant survival.

Acute Mechanical Circulatory Support for Cardiogenic Shock

Cardiogenic shock is associated with significant morbidity and mortality, and clinicians have increasingly used short-term mechanical circulatory support (MCS) over the last 15 years to manage outcomes. In general, the provision of greater hemodynamic support comes with device platforms that are more complex and potentially associated with more adverse events. In this review, we compare and contrast the available percutaneous and surgically placed device types used in cardiogenic shock and discuss the associated clinical and hemodynamic data to support device use.

Acceptable Post-Heart Transplant Outcomes Support Temporary MCS Prioritization in the New OPTN|UNOS Heart Allocation Policy

BACKGROUND

Temporary mechanical circulatory support (MCS) devices are generally used short term to maintain adequate organ perfusion in patients with advanced heart failure and cardiogenic shock. Unacceptably high waitlist mortality in this cohort motivated changes to heart allocation policy, which recognized the severity of illness by prioritization for temporary MCS and broader sharing in the new U.S. donor heart allocation policy. We evaluated the post-heart transplant outcomes for patients bridged with temporary MCS, a control population not bridged with MCS, and a cohort bridged with durable MCS.

METHODS

The heart transplant research database was queried to identify patients bridged with temporary MCS and bridged with durable MCS who went directly to heart transplant in our center. Temporary MCS included Impella, intra-aortic balloon pump, and extracorporeal membrane oxygenation. Post-transplant endpoints were assessed at 30 days, 6 months, and 1 year.

RESULTS

From 2010 to 2017, a total of 23 patients were bridged to heart transplant with temporary MCS and 548 were transplanted without MCS bridge. Patients bridged with temporary MCS had younger age, lower body mass index, and higher frequencies of prior blood transfusion and Status 1 (1A/1B) listing at transplant compared to patients not bridged with MCS (all P < .001). Despite the severity of illness in patients bridged with temporary MCS, post-transplant outcomes were indistinguishable from those in patients transplanted without MCS bridge, with no difference in 30-day, 6-month, or 1-year survival or 1-year freedom from cardiac allograft vasculopathy, nonfatal major adverse cardiac events, any-treated rejection, acute cellular rejection, or antibody-mediated rejection (P = .23-.97). Similarly, compared to 157 patients bridged with durable MCS, no differences in post-transplant outcomes were identified for the temporary MCS cohort (P = .15-.94).

CONCLUSION

Temporary MCS as a bridge to transplant achieves similar post-transplant outcomes at 1 year compared to no MCS and durable MCS. These encouraging findings support recent changes in the Organ Procurement and Transplantation Network | United Network Organ Sharing (OPTN|UNOS) adult heart allocation policy.

Favorable Outcomes of a Direct Heart Transplantation Strategy in Selected Patients on Extracorporeal Membrane Oxygenation Support

OBJECTIVES

Heart transplantation in patients supported by venoarterial extracorporeal membrane oxygenation has been associated with poor prognosis. A specific protocol for extracorporeal membrane oxygenation management encompassing patient selection, implantation strategy, and preoperative and perioperative treatment is applied at our institution. Our aim was to compare posttransplant outcomes of patients supported or not by extracorporeal membrane oxygenation at the time of heart transplantation.

DESIGN

A large observational single-center retrospective study was conducted. The primary endpoint was overall survival after heart transplantation. Secondary endpoints included death-censored rejection-free survival and the frequency of extracorporeal membrane oxygenation-related complications.

SETTING

One heart transplantation and extracorporeal membrane oxygenation high-volume center.

PATIENTS

All consecutive patients over 18 years old with a first noncombined heart transplantation performed between 2012 and 2016 were included.

INTERVENTIONS

None (retrospective observational study).

MEASUREMENTS AND MAIN RESULTS

Among the 415 transplanted patients, 118 (28.4%) were on extracorporeal membrane oxygenation at the time of transplantation (peripheral, 94%; intrathoracic, 6%). Median time on extracorporeal membrane oxygenation before heart transplantation was 9 days (interquartile range, 5-15 d) and median follow-up post heart transplantation was 20.7 months. Posttransplant survival did not differ significantly between the two groups (1-yr survival = 85.5% and 80.7% in extracorporeal membrane oxygenation vs nonextracorporeal membrane oxygenation patients; hazard ratio, 0.69; 95% CI, 0.43-1.11; p = 0.12, respectively). Donor age, body mass index, creatinine clearance, and ischemic time were independently associated with overall mortality, but not extracorporeal membrane oxygenation at the time of heart transplantation. Rejection-free survival also did not significantly differ between groups (hazard ratio, 0.85; 95% CI, 0.60-1.23; p = 0.39). Local wound infection was the most frequent complication after extracorporeal membrane oxygenation (37% of patients).

CONCLUSIONS

With the implementation of a specific protocol, patients bridged to heart transplantation on extracorporeal membrane oxygenation had similar survival compared with those not supported by extracorporeal membrane oxygenation.

Waitlist and post-transplant outcomes in patients listed with intra-aortic balloon pump for heart transplant: United Network for Organ Sharing registry

BACKGROUND

Intra-aortic balloon pump as bridge-to-transplant (BTT) has been used successfully in patients with refractory cardiogenic shock. However, the waitlist mortality in this population is high and predictors of waitlist mortality in this population are not known. We sought to identify predictors for waitlist mortality in patients listed with intra-aortic balloon pump and risk factors for 1-year mortality after heart transplant in this population.

METHODS

We identified patients listed for heart transplantation with intra-aortic balloon pump in the United Network for Organ Sharing data set from 1994 to 2015. Univariable and multivariable Cox proportional hazards models were used to identify predictors of waitlist mortality and 1-year post-transplant mortality.

RESULTS

From 1945 patients listed with intra-aortic balloon pump, 67.5% (N = 1313) were alive at 1 year and waitlist mortality was 32.5% (N = 632). We found that higher pulmonary vascular resistance, need for inotropes, and need for mechanical ventilation were associated with higher waitlist mortality. Mechanical ventilation and dialysis prior to transplantation were important predictors of 1-year post-transplant mortality.

CONCLUSION

Predictors of mortality such as high pulmonary vascular resistance, dialysis dependence, inotrope, and ventilator dependence in patients listed with intra-aortic balloon pump can help us identify those patients that are at high risk of dying prior to a heart transplantation.

Noteworthy Literature Published in 2018 for Thoracic Organ Transplantation

Publications of note from 2018 are reviewed for the cardiothoracic transplant anesthesiologist. Strategies to expand the availability of donor organs were highlighted, including improved donor management, accumulating experience with increased-risk donors, ex vivo perfusion techniques, and donation after cardiac death. A number of reports examined posttransplant outcomes, including outcomes other than mortality, with new data-driven risk models. Use of extracorporeal support in cardiothoracic transplantation was a prominent theme. Major changes in adult heart allocation criteria were implemented, aiming to improve objectivity and transparency in the listing process. Frailty and prehabilitation emerged as targets of comprehensive perioperative risk mitigation programs.

Optimization of heart allocation: The transplant risk score

The new French heart allocation system is designed to minimize waitlist mortality and extend the donor pool without a detrimental effect on posttransplant survival. This study was designed to construct a 1-year posttransplant graft-loss risk score incorporating recipient and donor characteristics. The study included all adult first single-organ recipients transplanted between 2010 and 2014 (N = 1776). This population was randomly divided in a 2:1 ratio into derivation and validation cohorts. The association of variables with 1-year graft loss was determined with a mixed Cox model with center as random effect. The predictors were used to generate a transplant-risk score (TRS). Donor-recipient matching was assessed using 2 separate recipient- and donor-risk scores. Factors associated with 1-year graft loss were recipient age >50 years, valvular cardiomyopathy and congenital heart disease, previous cardiac surgery, diabetes, mechanical ventilation, glomerular filtration rate and bilirubin, donor age >55 years, and donor sex: female. The C-index of the final model was 0.70. Correlation between observed and predicted graft loss rate was excellent for the overall cohort (r = 0.90). Hearts from high-risk donors transplanted to low-risk recipients had similar survival as those from low-risk donors. The TRS provides an accurate prediction of 1-year graft-loss risk and allows optimal donor-recipient matching.