Extracorporeal membrane oxygenation support and post-heart transplant outcomes among United States adults

Fifteen-year experience of direct bridge with venoarterial extracorporeal membrane oxygenation to heart transplantation

Objective

The study objective was to evaluate outcomes of patients directly bridged with venoarterial extracorporeal membrane oxygenation to heart transplantation.

Methods

A single-center retrospective study was performed on 1152 adult patients undergoing isolated cardiac transplantation between January 2007 and December 2021. Among these, patients bridged with an extracorporeal membrane oxygenation to transplantation (extracorporeal membrane oxygenation group, n = 317) were compared with standard cohorts of patients (no extracorporeal membrane oxygenation group, n = 835). A period analysis (Era 1, 2007-2013, vs Era 2, 2014-2021) was performed.

Results

Median duration of extracorporeal membrane oxygenation support before transplantation in the extracorporeal membrane oxygenation group was 8 days. Recipients of extracorporeal membrane oxygenation group were younger, with a better renal function and a shorter time on the waiting list. They were allocated to younger donors, with a longer ischemic time. The extracorporeal membrane oxygenation group and no extracorporeal membrane oxygenation group showed similar 1-year and 9-year survivals: 79.2% versus 79.4%, P = .98, and 56.2% versus 53.9%, P = .59, respectively. Period analysis in the extracorporeal membrane oxygenation group showed improved 1- and 9-year survivals in Era 2 compared with Era 1: 82.7% versus 71.1%, P = .021 and 60.4% versus 50.5%, P = .031, respectively. Era 2 was characterized by a higher rate of patients maintained on extracorporeal membrane oxygenation support after transplantation (92% vs 48%, P < .001), inserted mainly by peripheral cannulation (99.51% vs 57%, P < .001), for a shorter median duration after transplantation (5 vs 6 days, P = .033).

Conclusions

Extracorporeal membrane oxygenation as a direct bridge to heart transplantation shows similar outcomes to standard cohorts of patients. In the extracorporeal membrane oxygenation group, the waiting list time is shorter due to the emergency allocation system, and recipients have no evidence of organ dysfunction at the time of transplantation.

Three-year outcomes after bridge to transplantation ECMO-pre- and post-2018 UNOS revised heart allocation system

BACKGROUND

Utilization of temporary mechanical circulatory support, including veno-arterial extra-corporeal membrane oxygenation as a bridge to heart transplantation (HT) has increased significantly under the revised United Network for Organ Sharing (UNOS) donor heart allocation system. The revised heart allocation system aimed to lower waitlist times and mortality for the most critically ill patients requiring biventricular, nondischargeable, mechanical circulatory support. While previous reports have shown improved 1-year post-HT survival in the current era, 3-year survival and factors associated with mortality among bridge-to-transplant (BTT) extra-corporeal membrane oxygenation (ECMO) patients are not well described.

METHODS

We queried the UNOS database for all adult (age ≥ 18 years) heart-only transplants performed between 2010 and 2019. Patients were stratified as either pre- (January 2010-September 2018; era 1) or post-allocation change (November 2018-December 2019; era 2) cohort based on their HT date. Baseline recipient characteristics and post-transplant outcomes were compared. A Cox regression analysis was performed to explore risk factors for 3-year mortality among BTT-ECMO patients in era 2. For each era, 3-year mortality was also compared between BTT ECMO patients and those transplanted without ECMO support.

RESULTS

During the study period, 116 patients were BTT ECMO during era 1 and 154 patients during era 2. Baseline recipient characteristics were similar in both groups. Median age was 48 (36-58 interquartile range (IQR)) years in era 2, while it was 51 (27-58 IQR) years in era 1. The majority of BTT-ECMO patients were males in both era 2 and era 1 (77.7% vs 71.5%, p = 0.28). Median ECMO run times while listed for HT were significantly shorter (4 days vs 7 days, p < 0.001) in era 2. Waitlist mortality among BTT ECMO patients was also significantly lower in era 2 (6.3% vs 19.3%, p < 0.001). Post-HT survival at 6 months (94.2% vs 75.9%, p < 0.001), 1 year (90.3% vs 74.2%, p < 0.001), and 3 years (87% vs 66.4%, p < 0.001) was significantly improved in era 2 as compared to era 1. Graft failure at 1 year (10.3% vs 25.8%, p = 0.0006) and 3 years (13.6% vs 33.6%, p = 0.0001) was also significantly lower in era 2 compared to era 1. Three-year survival among BTT ECMO patients in era 2 was similar to that of patients transplanted in era 2 without ECMO support (87% vs 85.7%, p = 0.75). In multivariable analysis of BTT-ECMO patients in era 2, every 1 kg/m2 increase in body mass index was associated with higher mortality at 3 years (hazard ratio (HR) 1.09, 95% CI 1.02-1.15, p = 0.006). Similarly, both post-HT stroke (HR 5.58, 95% CI 2.57-12.14, p < 0.001) and post-HT renal failure requiring hemodialysis (HR 4.36, 95% CI 2.43-7.82, p < 0.001) were also associated with 3-year mortality.

CONCLUSIONS

Three years post-HT survival in patients bridged with ECMO has significantly improved under the revised donor heart allocation system compared to prior system. BTT ECMO recipients under the revised system have significantly shorter ECMO waitlist run times, lower waitlist mortality and 3-year survival similar to those not bridged with ECMO. Overall, the revised allocation system has allowed more rapid transplantation of the sickest patients without a higher post-HT mortality.

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.

Extracorporeal membrane oxygenation as a bridge to thoracic multiorgan transplantation

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) has emerged as a crucial tool in the care of patients with multiorgan failure and is increasingly utilized as a bridge to transplantation. While data on ECMO as a bridge to isolated heart and lung transplantation have been described, our emerging experience with ECMO as a bridge to thoracic multiorgan transplantation is not yet well understood.

METHODS

The United Network for Organ Sharing database was used to identify adult patients undergoing thoracic multiorgan transplantation between 1987 and 2022. Exclusion criteria were recipient age <18 and bridging with other non-ECMO mechanical circulatory support, Survival analysis was performed to compare outcomes between patients bridged to transplantation with ECMO and those who were not bridged.

RESULTS

Of 3,927 patients undergoing thoracic multiorgan transplantation, a total of 203 (5.2%) patients received ECMO as a bridge to transplantation. Among ECMO recipients, patients were most commonly bridged to heart-lung (45.8%), followed by heart-kidney (34.5%), and lung-kidney transplantation (11.8%). At a median follow-up of 35.5 months, unadjusted survival among patients bridged with ECMO was decreased versus multiorgan transplant recipients who were not bridged (p < 0.001). Among patients surviving past 30 days following transplantation, conditional long-term survival was similar between ECMO and non-ECMO patients (p = 0.82).

CONCLUSIONS

ECMO is increasingly utilized as a bridge to thoracic multiorgan transplantation and is associated with increased 30 day mortality and decreased long-term survival. In select patients surviving to 30 days following transplantation, similar long-term survival is seen between patients bridged with ECMO and those not bridged.

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.

Contemporary Bridge to Heart Transplantation With Venoarterial Extracorporeal Membrane Oxygenation

Objective: In October 2018, the United Network for Organ Sharing changed their heart allocation criteria to prioritize patients on temporary mechanical circulatory support. This study assesses outcomes of patients bridged to orthotopic heart transplantation (OHT) with venoarterial extracorporeal membrane oxygenation (VA ECMO) since this change. Methods: We conducted a retrospective single-center study of adults (≥18 years) supported with VA ECMO at the time of OHT (October 1, 2018, to December 31, 2021). The primary outcome was midterm survival. Results: During the study period, 117 patients underwent OHT including 52 adults ≥18 years (44%) and 65 children <18 years (56%). Among adults, 8 (15%) were supported with VA ECMO at the time of OHT and are included in this study; 75% were male (n = 6), and the median age was 52.5 (interquartile range [IQR] = 23.5 to 57.25) years. Most patients were peripherally cannulated (75%, n = 6) and supported with an intra-aortic balloon pump during the pretransplant period (87.5%, n = 7). The median ECMO duration was 7 (IQR = 4.5 to 25.25) days. Three patients experienced complications on ECMO (37.5%), including thromboembolic bowel infarction (12.5%, n = 1) and bleeding requiring reintervention (25%, n = 2). All patients survived to discharge without posttransplantation complications and were alive at the latest follow-up. The median follow-up time was 24.8 (IQR = 19.5 to 28.2) months. Conclusions: Patients can be successfully bridged with VA ECMO directly to OHT with excellent midterm results. Key contributors to our outcomes include early extubation, use of bivalirudin over heparin, ambulation, and rehabilitation while on ECMO.

Prognostic Value of APACHE IV Score in Patients Bridged to Heart Transplantation on ECMO

BACKGROUND

Methods for risk stratification of candidates for heart transplantation (HTx) supported by extracorporeal membrane oxygenation (ECMO) are limited. We evaluated the reliability of the APACHE IV score to identify the risk of mortality in this patient subset in a multicenter study.

METHODS

Between January 2010 and December 2022, 167 consecutive ECMO patients were bridged to HTx; they were divided into two groups, according to a cutoff value of APACHE IV score, obtained by receiver operating characteristic curve analysis for 90-day mortality. Kaplan-Meier survival curves were plotted, and compared through the log-Rank test. Cox regression model was used to estimate which factors were associated with survival.

RESULTS

The 90-day mortality prediction of the APACHE IV score showed an area under the curve of 0.87 (95% CI: 0.80-0.94), with a cutoff value of 49 (specificity 91.7%-sensibility 69.6%). 125 patients (74.8%) showed an APACHE IV score value < 49 (Group A), and 42 (25.2%) ≥ 49 (Group B). 90-day mortality was 11.2% in Group A and 76.2% in Group B (p < 0.01). Survival at 1 and 5 years was 85.5%, 77% versus 23.4%, 23.4% (p < 0.01) in Groups A and B. Mortality correlated at univariable analysis with recipient age, body mass index, mechanical ventilation, APACHE IV score, and platelets number. At multivariable analysis only APACHE IV score (HR: 1.07 [1.05-1.09, 95% CI]) independently affected survival.

CONCLUSIONS

The APACHE IV score represents a powerful predictor of survival in patients bridged to HTx on ECMO support, and could guide candidacy of patients on ECMO.

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.

Patient-centered weaning from venoarterial extracorporeal membrane oxygenation: "A practice-oriented narrative review of literature"

Venoarterial extracorporeal membrane oxygenation (V-A ECMO) is increasingly used in cardiogenic shock for rapid stabilization and bridging towards recovery, long-term mechanical circulatory support or transplant. Although technological advances have instigated its widespread use, the complex, long-lasting ECMO care creates a significant strain on hospital staff and resources. Therefore, optimal clinical management including timely decisions on ECMO removal and further therapy are pivotal, yet require a well-structured weaning approach. Although dedicated guidelines are lacking, a variety of weaning protocols have distillated echocardiographic and hemodynamic predictors for successful weaning. Nevertheless, a strikingly high mortality up to 70% after initial successful weaning raises concerns about the validity of current weaning strategies. Here, we plead for a patient-tailored approach including a bailout strategy when weaning fails. This should account not only for left- but also right ventricular function and interdependence, as well as the temporal course of cardiac recovery in function of extracorporeal support. Patients with a high risk of weaning failure should be identified early, enabling timely transportation to an advanced heart failure center. This review summarizes predictors of successful weaning and discusses all relevant elements for a structured weaning approach with a central role for patient-specific clinical considerations and echocardiography.

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.

Extracorporeal membrane oxygenation as a bridge to advanced heart failure therapies

BACKGROUND

Venoarterial extracorporeal membrane oxygenation (VA-ECMO) is a key support modality for cardiogenic shock. The 2018 United Network for Organ Sharing (UNOS) heart transplant allocation algorithm prioritizes VA-ECMO patients.

OBJECTIVE

To evaluate the role of VA-ECMO in bridging to advanced heart failure therapies.

METHODS

We analyzed adult patients from the multicenter Extracorporeal Life Support Organization registry receiving VA-ECMO for cardiac support or resuscitation between 2016 and 2021 in the United States, comparing bridge-to-transplant (BTT) and non-BTT intent patients, as well as pre- vs post-2018 patients, on a wide range of demographic and clinical outcome predictors.

RESULTS

Of 17,087 patients, 797 received left ventricular assist device (LVAD)/heart transplant, 7,931 died or had poor prognosis, and 8,359 had expected recovery at ECMO discontinuation. Patients supported with BTT intent had lower clinical acuity than non-BTT candidates and were more likely to receive LVAD/transplant. The proportion of patients who received VA-ECMO as BTT and received LVAD/transplant increased after 2018. Post-2018 BTT patients had significantly lower clinical acuity and higher likelihood of transplant than both post-2018 non-BTT patients and pre-2018 BTT patients. ECMO complications were associated with lower likelihood of transplant but were significantly less common post-2018 than pre-2018.

CONCLUSIONS

After implementation of the 2018 UNOS allocation system, ECMO utilization as BTT or LVAD has increased, and the acuity of BTT intent patients cannulated for ECMO has decreased. There has not yet been an increase in more acute ECMO patients getting transplanted. This may partially explain the post-transplant outcomes of ECMO patients in the current era reported in UNOS.

Prognosticating Mortality of Primary Cardiogenic Shock Requiring Extracorporeal Life Support: The RESCUE Score

We aimed to identify prognostic laboratory markers during extracorporeal life support (ECLS) in patients with primary refractory cardiogenic shock (RCS) and to create a preliminary specific mortality score. All 208 consecutive subjects admitted for primary RCS and treated with ECLS between January-2009 and December-2018 were retrospectively analyzed. Multivariate regression analysis on laboratory markers during the first nine days of ECLS was used to develop a "Refractory End-stage Shock CUred with Ecls" (RESCUE) score. Serum creatinine (OR = 3.72, 95%CI: 2.01-6.88), direct bilirubin (OR = 1.40, 95%CI: 1.05-1.8), and platelet count (OR = 0.62, 95%CI: 0.42-0.94) were independent predictors of in-hospital mortality and were included in the score. The mean AUC was 0.763 (95%CI: 0.698-0.828) in the development cohort and 0.729 (95%CI: 0.664-0.794) in the bootstrap internal validation cohort. The RESCUE score represents a novel promising instrument to predict early mortality during the first critical days of ECLS and to help in properly guiding the therapeutic decision-making process.

Direct Extracorporeal Membrane Oxygenation Bridged Heart Transplantation: The Importance of Multi-Organ Failure

Background and Objectives

Recently, approximately 40% of all heart transplantation (HTx) in South Korea are performed using the direct extracorporeal membrane oxygenation (ECMO) bridging method. We conducted a study to examine the clinical outcome of direct ECMO-bridged HTx and to investigate the impact of multi-organ failure (MOF).

Methods

From June 2014 to September 2022, a total of 96 adult patients who underwent isolated HTx at a single tertiary hospital were included in the study. The patients were sub-grouped into ECMO (n=48) and non-ECMO group (n=48), and the ECMO group was subdivided into awake (n=22) and non-awake (n=26) groups based on mechanical ventilator (MV) dependency. Baseline characteristics, 30-day, and 1-year mortality were analyzed retrospectively.

Results

The 1-year survival rate was significantly lower in the ECMO group (72.9% vs. 95.8%, p=0.002). There was a significant difference in the 30-day survival rate between the awake and non-awake ECMO groups (81.8% vs. 65.4%, p=0.032). In the univariate analysis of logistic regression for 1-year mortality, the odds ratio was 8.5 for ECMO bridged HTx compared to the non-ECMO group, 12.3 in patients who required MV (p=0.003), and 23 with additional hemodialysis (p<0.001).

Conclusions

Patients who required MV in ECMO bridged HTx showed higher preoperative MOF rates and early mortality than those extubated. When considering ECMO bridged HTx, the severity of MOF should be thoroughly investigated, and careful patient selection is necessary.

Discontinuation of ECMO-a review with a note on Indian scenario

Extracorporeal membrane oxygenation (ECMO) has strikingly progressed over the last 20 years in the management of adult and pediatric severe respiratory and cardiac dysfunctions refractory to conventional management. In this review, we will discuss the weaning strategies of veno-venous and veno-arterial ECMO including the bridge to recovery and bridge to transplant along with post-ECMO care. We will also discuss the futility and the management of bridge to nowhere from Indian perspectives.

State of the art - Extracorporeal membrane oxygenation as a bridge to thoracic transplantation

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) has revolutionized the treatment of refractory cardiac and respiratory failure, and its use continues to increase, particularly in adults. However, ECMO-related morbidity and mortality remain high.

MAIN TEXT

In this review, we investigate and expand upon the current state of the art in thoracic transplant and extracorporeal life support (ELS). In particular, we examine recent increase in incidence of heart transplant in patients supported by ECMO; the potential changes in patient care and selection for transplant in the years prior to updated United Network for Organ Sharing (UNOS) organ allocation guidelines versus those in the years following, particularly where these guidelines pertain to ECMO; and the newly revived practice of heart-lung block transplants (HLT) and the prevalence and utility of ECMO support in patients listed for HLT.

CONCLUSIONS

Our findings highlight encouraging outcomes in patients bridged to transplant with ECMO, considerable changes in treatment surrounding the updated UNOS guidelines, and complex, diverse outcomes among different centers in their care for increasingly ill patients listed for thoracic transplant.

Risk stratification of patients listed for heart transplantation while supported with extracorporeal membrane oxygenation

OBJECTIVES

Extracorporeal membrane oxygenation (ECMO) is used to support patients in severe cardiogenic shock. In the absence of recovery, these patients may need to be listed for heart transplant (HT), which offers the best long-term prognosis. However, posttransplantation mortality is significantly elevated in patients who receive ECMO. The objective of the present study was to describe and risk-stratify different profiles of patients listed for HT supported by ECMO.

METHODS

Patients listed for HT in the United Network for Organ Sharing database were analyzed. The primary outcome was 1-year survival and was assessed in patients bridged to transplant with ECMO (ECMO_BTT) and patients who were previously supported on ECMO but had it removed before HT (ECMO_REMOVED).

RESULTS

Among 65,636 adult candidates listed for HT (between 2001 and 2017), 712 were supported on ECMO, 292 of whom (41%) underwent HT (ECMO_BTT, n = 202; ECMO_REMOVED, n = 90). Most of the patients with ECMO_REMOVED were transplanted with a ventricular assist device. In ECMO_BTT, recipient age (each 10-year increase), time on the waitlist (both defined as minor risk factors), need for dialysis, and need for mechanical ventilation (both defined as major risk factors) were independent predictors of mortality. ECMO_REMOVED and ECMO_BTT with no risk factors showed 1-year survival comparable to that in patients who were never supported on ECMO. Compared with patients who were never on ECMO, patients in ECMO_BTT group with minor risk factors, 1 major risk factor, and 2 major risk factors had ~2-, ~5-, and >10-fold greater 1-year mortality, respectively (P < .05).

CONCLUSIONS

The HT recipients in the ECMO_REMOVED and ECMO_BTT groups with no risk factors showed similar survival as the HT recipients who were never supported on ECMO. In the ECMO_BTT group, posttransplantation mortality increased significantly with increasing risk factors.

Donor heart selection: Evidence-based guidelines for providers

The proposed donor heart selection guidelines provide evidence-based and expert-consensus recommendations for the selection of donor hearts following brain death. These recommendations were compiled by an international panel of experts based on an extensive literature review.

Veno-Arterial Extracorporeal Membrane Oxygenation as a Bridge to Heart Transplant-Change of Paradigm

Despite advances in medical therapy and mechanical circulatory support (MCS), heart transplant (HT) remains the gold standard therapy for end-stage heart failure. Patients in cardiogenic shock require prompt intervention to reverse hypoperfusion and end-organ damage. When medical therapy becomes insufficient, MCS should be considered. Historically, it has been reported that critically ill patients bridged with veno-arterial extracorporeal membrane oxygenation (VA-ECMO) directly to HT have worse outcomes. However, when the heart allocation system gives the highest priority to patients on VA-ECMO support, those patients have a higher incidence of HT and a lower incidence of death or removal from the transplant list. Moreover, patients with a short waiting time on VA-ECMO have a similar hazard of mortality to non-ECMO patients. According to the reported data, bridging with VA-ECMO directly to HT may be a solution in the selection of critically ill patients when the anticipated waiting list time is short. However, when a prolonged waiting time is expected, more durable MCS should be considered. Regardless of the favorable results of the direct bridging to HT with ECMO in selected patients, the superiority of this strategy compared to the bridge-to-bridge strategy (ECMO to durable MCS) has not been established and further studies are mandatory in order to clarify this issue.

Postoperative Outcomes in Infants Undergoing ABO-incompatible Heart Transplantation in the United States

BACKGROUND

ABO-incompatible heart transplant is a method to increase the infant donor pool. However data on long-term survival and rejection after ABO-incompatible heart transplant in recent era are limited.

METHODS

The United Network for Organ Sharing database was queried for infant heart transplants performed from January 2008 to March 2020. Patient demographics and known risk factors for posttransplant mortality were collected. Statistical analysis using Bayesian additive regression trees was performed to evaluate the association of ABO incompatibility and overall survival, graft survival, acute rejection episodes, and length of stay.

RESULTS

Of 1368 included infants (age < 1 year), 280 (20.47%) were ABO incompatible. ABO incompatibility was not associated with increased all-cause mortality, acute rejection episodes, or length of stay, whereas extracorporeal membrane oxygenation and intubation status of the recipient at the time of transplantation were associated with increased all-cause mortality and graft failure. Idiopathic cardiomyopathy was associated with a decreased likelihood of posttransplant all-cause mortality. One-, 5-, and 10-year survival rates among compatible vs incompatible transplants were estimated to be 90% vs 88%, 82% vs 79%, and 77% vs 73%, respectively.

CONCLUSIONS

ABO-incompatible infant heart transplant does not affect posttransplant survival, incidence of rejection, or postoperative length of stay. Therefore it remains a viable and important strategy to increase the infant donor pool.

Impact of duration of mechanical support on heart transplantation: Hasty transplantation may not have a good long-term outcome

BACKGROUND

Mechanical circulatory support (MCS) has been widely utilized in critically ill cardiac transplant candidates. Few studies have investigated the impact of duration of MCS before heart transplantation (HTx) on long-term patient survival.

METHODS

A retrospective HTx database was reviewed between 2009 and 2019. Patients who did not or did undergo MCS before HTx were categorized into two groups: (1) A (did not) and (2) B (did), respectively. A receiver operating characteristic (ROC) curve was plotted to assess the cutoff level of MCS duration before HTx in evaluating 5-year survival.

RESULT

A total of 270 HTx patients (group A: 120, group B: 150) were analyzed. Group B patients had a higher percentage of blood type O, a higher incidence of resuscitation, a shorter listing duration, and a higher likelihood of having United Network for Organ Sharing (UNOS) 1A status than group A. The ROC curve revealed 24 days as a good cut-off level for determining the best MCS before HTx timing. Group B was categorized into two subgroups: (1) B1 (MCS < 24 days, n = 65) and (2) B2 (MCS > 24 days, n = 85). B2 had a higher incidence of cardiopulmonary resuscitation (CPR), hemodialysis, longer waiting time after MCS, and better ventricular assist device implantation than B1. However, the survival curves showed that B1 outcomes were significantly worse than in groups A and B2. Groups A and B2 had similar survival curves without an increased incidence of infection.

CONCLUSION

The preliminary data demonstrated that a longer duration of MCS may be associated with better outcomes than urgent HTx.

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.

Extracorporeal membrane oxygenation as a bridge to durable mechanical circulatory support or heart transplantation

BACKGROUND

Patients with cardiogenic shock may require extracorporeal membrane oxygenation (ECMO) prior to durable mechanical circulatory support (dMCS) or heart transplantation (HTx).

METHODS

We investigated the clinical characteristics and outcomes of adult patients with ECMO support as bridge to dMCS or HTx between 1/1/13 and 12/31/20.

RESULTS

Of 57 patients who underwent bridging ECMO, 41 (72%) received dMCS (approximately half with biventricular support) and 16 (28%) underwent HTx, 13 (81%) after the 2018 UNOS allocation system change. ECMO → HTx patients had shorter ventilatory time (3.5 vs 7.5 days; p = 0.018), ICU stay (6 vs 18 days; p = 0.001), and less need for inpatient rehabilitation (18.8% vs 57.5%; p = 0.016). The 1-year survival post HTx was 81.3% in the ECMO → HTx group and 86.4% in the ECMO → dMCS group (p = 0.11). For those patients in the ECMO → dMCS group who did not undergo HTx, 1-year survival was significantly lower, 31.6% (p = 0.001).

CONCLUSION

Patients on ECMO who undergo HTx, with or without dMCS bridge, have acceptable post-HTx survival. These findings suggest that HTx from ECMO is a viable option for carefully selected patients deemed acceptable to proceed with definitive advanced therapies, especially in the era of the new UNOS allocation system.

Bridge to transplantation from mechanical circulatory support: a narrative review

Objective

To highlight recent developments in the utilization of mechanical circulatory support (MCS) devices as bridge-to-transplant strategies and to discuss trends in MCS use following the changes to the United Network for Organ Sharing (UNOS) heart allocation system.

Background

MCS devices have played an increasingly important role in the treatment of heart failure patients. Over the past several years, technological advancements have led to new developments in MCS devices and expanding indications for MCS use. In October of 2018, the UNOS heart allocation policy was revised to prioritize higher-urgency patients, including those supported with temporary MCS devices. Since then, changes in trends of MCS utilization have been observed.

Methods

Articles from the PubMed database regarding the use of MCS devices as bridge-to-transplant strategies were reviewed.

Conclusions

Over the past decade, utilization of temporary MCS devices, which include the intra-aortic balloon pump (IABP), percutaneous ventricular assist devices (pVADs), and extracorporeal membrane oxygenation (ECMO), has become increasingly common. Recent advancements in MCS include the development of pVADs that can fully unload the left ventricle (LV) as well as devices designed to provide right-sided support. Technological advancements in durable left ventricular assist devices (LVADs) have also led to improved outcomes both on the device and following heart transplantation. Following the 2018 UNOS heart allocation policy revision, the utilization of temporary MCS in advanced heart failure patients has further increased and the proportion of patients bridged directly from a temporary MCS device has exponentially risen. However, following the start of the COVID-19 pandemic, the trends have reversed, with a decrease in the percentage of patients bridged from a temporary MCS device. As long-term data following the allocation policy revision becomes available, future studies should investigate how trends in MCS use for patients with advanced heart failure continue to evolve.

Contemporary contribution of cardiac surgery for the treatment of cardiomyopathies and pericardial diseases

Cardiomyopathy refers to a spectrum of heterogeneous myocardial disorders characterized by morphological and structural alterations leading eventually to heart failure, by affecting cardiac filling and/or the cardiac systolic function. Heart transplantation is currently the gold standard surgical treatment for patients with heart failure, with a median survival in adults of 12 years according to international registries. However, the limited available donor pool does not allow its extensive employment. For this reason, mechanical circulatory supports are increasingly used, and in the short term are becoming as possible alternatives to heart transplantation, owing to improved technologies and increased biocompatibility. However, long-term outcomes of mechanical assist devices are still burdened with a high rate of adverse events. Conventional surgical treatments could be still considered as alternatives to heart replacement treatment when tailored both on patient clinical conditions and etiology of cardiac diseases. In particular, among patients affected by ischemic cardiomyopathy, coronary artery bypass grafting has proven to improve survival when associated to optimal medical treatment, and surgical ventricular restoration might be considered as a valid treatment in particular cases. Correction of functional mitral valve regurgitation by mitral annuloplasty, which aims to restore left ventricular geometry, has not demonstrated unambiguous results, and outcomes of this procedure are still controversial. Pericardial pathology becomes of surgical interest when it is responsible for a reduced filling capacity of the heart chambers, which can develop acutely (cardiac tamponade) or chronically (as in the case of constrictive pericarditis). This review focuses on the different surgical approaches that could be adopted to treat patients with heart failure and pericardial diseases.

Veno-arterial Extracorporeal Membrane Oxygenation as Bridge to Heart Transplantation: The Way Forward

Advanced heart failure (HF) represents a public health priority due to the increase of affected patients and the meaningful mortality. Durable mechanical circulatory support (MCS) and heart transplantation (HTx) are unique therapies for end-stage HF (ESHF), with positive early and long-term outcomes. The patients who underwent HTx have a 1-y survival of 91% and a median survival of 12-13 y, whereas the median survival of ESHF is <12 mo. Short-term MCS with veno-arterial extracorporeal membrane oxygenation (VA ECMO) can be used as a bridge to transplantation strategy. Patients bridged with VA ECMO have significantly lower survival in comparison with non-MCS bridged and left ventricular assist device-bridged patients. VA ECMO represents an effective, and sometimes unique, system to obtain rapid hemodynamic stabilization, but possible negative effects on patients' outcomes after HTx must be considered. Here, we discuss the use of VA ECMO as bridge to transplantation.

Association Between Variants in Calcineurin Inhibitor Pharmacokinetic and Pharmacodynamic Genes and Renal Dysfunction in Adult Heart Transplant Recipients

Background: The goal of the study was to assess the relationship between single nucleotide variants (SNVs) in calcineurin inhibitor (CNI) pharmacokinetic and pharmacodynamic genes and renal dysfunction in adult heart transplant (HTx) recipients. Methods: This retrospective analysis included N = 192 patients receiving a CNI at 1-year post-HTx. Using a candidate gene approach, 93 SNVs in eight pharmacokinetic and 35 pharmacodynamic genes were chosen for investigation. The primary outcome was renal dysfunction 1-year after HTx, defined as an estimated glomerular filtration rate (eGFR) <45 ml/min/1.73m2. Results: Renal dysfunction was present in 28.6% of patients 1-year after HTx. Two SNVs [transforming growth factor beta 1 (TGFB1) rs4803455 C > A and phospholipase C beta 1 (PLCB1) rs170549 G > A] were significantly associated with renal dysfunction after accounting for a false discovery rate (FDR) of 20%. In a multiple-SNV adjusted model, variant A allele carriers of TGFB1 rs4803455 had lower odds of renal dysfunction compared to C/C homozygotes [odds ratio (OR) 0.28, 95% CI 0.12-0.62; p = 0.002], whereas PLCB1 rs170549 variant A allele carriers had higher odds of the primary outcome vs. patients with the G/G genotype (OR 2.66, 95% CI 1.21-5.84, p = 0.015). Conclusion: Our data suggest that genetic variation in TGFB1 and PLCB1 may contribute to the occurrence of renal dysfunction in HTx recipients receiving CNIs. Pharmacogenetic markers, such as TGFB1 rs4803455 and PLCB1 rs170549, could help identify patients at increased risk of CNI-associated renal dysfunction following HTx, potentially allowing clinicians to provide more precise and personalized care to this population.

ECMO as a Bridge to Left Ventricular Assist Device or Heart Transplantation

OBJECTIVES

The purpose of this study was to compare outcomes between patients on extracorporeal membrane oxygenation (ECMO) bridged to left ventricular assist device (LVAD) versus heart transplantation (HT) using registry data.

BACKGROUND

Patients with heart failure supported with ECMO represent the highest priority in the new HT allocation system. For patients on ECMO, bridging to LVAD may be non-inferior compared with bridging to HT.

METHODS

Adult patients in the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) from 2006 to 2017 and United Network for Organ Sharing (UNOS) database from 2006 to June 2019 requiring ECMO were included. Cause-specific hazard models were created and cumulative incidence functions were calculated with mortality, transplantation, and re-transplantation as competing events.

RESULTS

A total of 906 patients received ECMO as bridge to VAD (n = 587, 64.8%) or as bridge to HT (n = 319, 35.2%). Patients bridged directly to HT were younger (age 46.3 ± 15.4 years vs. 52.1 ± 13.2 years; p < 0.001) and more likely to be female (93 [29.2%] vs. 139 [23.7%]; p = 0.022). Patients bridged directly to HT were more likely to have a nonischemic cardiomyopathy, restrictive physiologies, and allograft failure; (p < 0.05 for all). ECMO use increased over time in both UNOS and INTERMACS. There was no significant difference in mortality between groups (Gray's p = 0.581). This remained true even when the analysis was restricted to transplant-listed or eligible patients as well as patients with dilated phenotypes (excluding patients with congenital heart disease, restrictive phenotypes, and allograft failure).

CONCLUSIONS

There was no difference in mortality on pump support compared with posttransplant mortality among those bridged from ECMO to LVAD or HT.

Use of durable left ventricular assist devices for high-risk patients: Korean experience before insurance coverage

Background

Left ventricular assist devices (LVADs) were not covered by the Korean national insurance until September 2018, and they were implanted at the patient’s own or a third party’s expense. However, there have been no reports on using an LVAD without insurance coverage or manufacturer support.

Methods

We reviewed 23 patients who underwent durable LVAD implantation at our institution from August 2012 to September 2018. Patients with temporary LVADs using extracorporeal or paracorporeal circulation were excluded. The available devices were the HeartMate II^TM (HMII) and HeartWare^TM Ventricular Assist Device (HVAD). The primary outcome was 30-day mortality. The secondary outcomes were postoperative complications and late mortality.

Results

The mean age of the patients was 68.7±9.9 years. The study sample comprised six female (26.1%) and 17 male (73.9%) patients. All patients had modifiable (bridge to candidacy) or unmodifiable absolute (destination therapy) contraindications for heart transplantation (HT). Among the patients in this study, 12 (52.2%) had ischemic cardiomyopathy and 11 (47.8%) had non-ischemic cardiomyopathy. Nine patients (39.1%) had temporary mechanical circulatory support such as extracorporeal membrane oxygenation or a temporary LVAD in place preoperatively. The average duration of LVAD support was 618.6±563.2 days (range, 59–2,285 days). There was no 30-day mortality. Four patients (17.4%) underwent HT. Six patients (26.1%) underwent re-exploration for postoperative bleeding, and one patient (4.3%) had a disabling stroke after discharge. The estimated survival rates at 12 and 24 months were 89.2% and 68.8%, respectively.

Conclusions

All patients who received LVADs before insurance coverage had contraindications for HT. The overall outcomes were comparable with those reported in the international registry.

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.

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.

What are the results of venoarterial extracorporeal membrane oxygenation bridging to heart transplantation?

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was whether heart transplantation is a viable treatment option in patients in refractory cardiogenic shock who could not be weaned off venoarterial extracorporeal membrane oxygenation (VA ECMO). Altogether, 373 papers were found using the reported search, of which 7 papers represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. Evidence is derived from 3 papers based on registry analysis, 1 multi-institutional study and 3 single-institution reviews. Early post-transplant mortality of ECMO-bridged recipients ranges from 18.7% to 33.3% and 1-year survival from 44.6% to 72.0%. High acuity of recipient illness reflected by poor renal function, mechanical ventilation, advanced age, elevated serum lactate predict inferior outcome. We conclude that heart transplantation results in patients bridged with VA ECMO are inferior when compared to published outcome of non-bridged recipients. In the era of severe organ shortage and intense public and regulatory scrutiny of the results, the decision to transplant a patient directly of VA ECMO needs to be made on a case-by-case basis. Potential gain in decreasing the waiting list mortality of these critically ill patients needs to be weighed against poorer post-transplantation mortality rates and mid- and long-term outcomes.

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.

ECMO in cardiogenic shock and bridge to heart transplant

Purpose

The aim of this review is to discuss the role of extracorporeal membrane oxygenation (ECMO) in cardiogenic shock and its use to bridge patients to heart transplantation.

Methods and results

Consideration of published literature reveals indications for ECMO in cardiogenic shock and tools for patient selection, adequate evidence of its efficacy, its advantages when compared with other temporary mechanical circulatory support devices and details of its use as a bridge to decision, bridge to recovery, bridge to bridge (durable ventricular assist device) and bridge to heart transplant.

Conclusion

ECMO is invaluable in treating patients with medically refractory profound cardiogenic shock and allows for cardiac recovery or planning for permanent heart replacement treatments.

Veno-Arterial Extracorporeal Membrane Oxygenation for Cardiogenic Shock

Extracorporeal membrane oxygenation has evolved, from a therapy that was selectively applied in the pediatric population in tertiary centers, to more widespread use in diverse forms of cardiopulmonary failure in all ages. We provide a practical review for cardiovascular clinicians on the application of veno-arterial extracorporeal membrane oxygenation in adult patients with cardiogenic shock, including epidemiology of cardiogenic shock, indications, contraindications, and the extracorporeal membrane oxygenation circuit. We also summarize cannulation techniques, practical management and troubleshooting, prognosis, and weaning and exit strategies, with attention to end of life and ethical considerations.

Implication of Ventricular Assist Devices in Extracorporeal Membranous Oxygenation Patients Listed for Heart Transplantation

The new allocation criteria classify patients on veno-arterial extracorporeal membranous oxygenation (VA-ECMO) as the highest priority for receiving orthotopic heart transplantation (OHT) especially if they are considered not candidates for ventricular assist devices. The outcomes of patients who receive ventricular assist devices (VADs) after being listed for heart transplantation with VA-ECMO is unknown. We analyzed 355 patients listed for OHT with VA-ECMO from the United Network for Organ Sharing database from 2006 to 2014. Univariate and multivariate Cox proportional-hazards models were used to determine the contribution of prognostic variables to the outcome. Thirty-three patients (9.3%) received VADs (15 dischargeable, 7 non-dischargeable VADs). The VAD and non-VAD groups had similar listing characteristics except that the VAD group were more likely to have non-ischemic cardiomyopathy (48.5% vs. 25.2%), and less likely to be obese (6.1% vs. 25.2%) or have a history of prior organ transplant (3% vs. 31.1%). Patients who underwent VAD implantation had more days on the list (median 189 vs. 14 days) compared to the non-VAD group. Amongst the patients who had VADs, (25/33) 75.5% patients were subsequently transplanted with similar post-transplant survival compared to the non-VAD group (72% vs. 60.5%; p = 0.276). Predictors of one-year post-transplant mortality included panel reactive antibodies (PRA) class I ≥ 20%, recipient smoking history, increased serum creatinine and total bilirubin. Therefore, a small proportion of patients listed for transplantation with VA ECMO undergo VAD implantation. Their waitlist survival is better than non-VAD group but with similar post-transplant survival.

Five years' experience with a peripheral veno-arterial ECMO for mechanical bridge to heart transplantation

Background

Mechanical circulatory support (MCS) is the only way to save a life for heart transplant candidates and to decrease of waiting list mortality. The choice between short- or long-term pretransplant MCS depends on of type and severity of CHF. One of the most frequently used methods of temporary MSC before orthotopic heart transplantation (OHTx) is veno-arterial extracorporeal membrane oxygenation (VA ECMO). The aim of this study was to analyze own experience of peripheral VA ECMO (pVA ECMO) in heart transplant candidates needed in urgent HT.

Methods

This study included 182 pts [160 (87.9%) men and 22 (12.1%) female, age 43±1.2 yrs] supported with pVA ECMO in the period from 01. 01. 2013 to 31. 12. 2017 or 23.2% from all waiting list (n=786).

Results

During VA ECMO, 16 (8.8%) of the 182 pts died. In most pts [n=13 (81.3%)] multiorgan failure/sepsis were the cause of death. One hundred and sixty-six (91.2%) pts were successfully bridged to OHTx or 27.9% from all heart transplant recipients (n=594) (2013-2017 yrs). The duration of pVA ECMO before OHTx (n=166) was 5.8±3.2 days. One hundred and forty-three (86.1%) from 166 pts were discharged to home. Post-transplant survival among heart transplant recipient with pre-transplant MCS by pVA ECMO was in comparison with recipients without pretransplant MCS [84.2% vs. 90.1% (6 months), 83.3% vs. 91.8% (1 years), 75.1% vs. 86.1% (2 years), 74.2% vs. 85.8% (3 years), 72.3% vs. 84.7% (4 years), 72.3% vs. 83.5% (5 years) respectively (P<0.0001)].

Conclusions

pVA ECMO is a useful tool of treatment of patients with INTERMACS profile 1/2. Results of OHTx at recipients bridged with VA ECMO are less successful that recipients without pre-transplant MCS. VA ECMO should be considered as a direct bridge to OHTx in conditions of limited financial resources of health care and high availability of donor's hearts.

Diagnostic and therapeutic approach to infectious diseases in solid organ transplant recipients

Purpose

Prognosis of solid organ transplant (SOT) recipients has improved, mainly because of better prevention of rejection by immunosuppressive therapies. However, SOT recipients are highly susceptible to conventional and opportunistic infections, which represent a major cause of morbidity, graft dysfunction and mortality.

Methods

Narrative review.

Results

We cover the current epidemiology and main aspects of infections in SOT recipients including risk factors such as postoperative risks and specific risks for different transplant recipients, key points on anti-infective prophylaxis as well as diagnostic and therapeutic approaches. We provide an up-to-date guide for management of the main syndromes that can be encountered in SOT recipients including acute respiratory failure, sepsis or septic shock, and central nervous system infections as well as bacterial infections with multidrug-resistant strains, invasive fungal diseases, viral infections and less common pathogens that may impact this patient population.

Conclusion

We provide state-of the art review of available knowledge of critically ill SOT patients with infections.

VA-ECMO for cardiogenic shock in the contemporary era of heart transplantation: Which patients should be urgently transplanted?

With the impending United Network for Organ Sharing (UNOS) heart allocation policy giving VA-ECMO supported heart transplant (HT) candidates highest priority status (Tier 1), identifying patients in cardiogenic shock (CS) with severe and irreversible heart failure (HF) appropriate for urgent HT is critically important. In a center where wait times currently preclude this approach, we retrospectively reviewed 119 patients (ages 18-72) with CS from 1/2014 to 12/2016 who required VA-ECMO for >24 hours. Underlying aetiologies included postcardiotomy shock (45), acute coronary syndromes (33), and acute-on-chronic HF (16). Eighty-four percent of patients (100) had ≥1 contraindication to HT with 61.3% (73) having preexisting contraindications (eg, multiorgan dysfunction and substance abuse), and 68.1% (81) experienced preclusive complications (eg, renal failure, coagulopathy, and infection). Potential HT candidates were significantly more likely to survive to discharge (potential HT candidates 84.2% vs preexisting contraindications 43.8% vs contraindications developing on VA-ECMO 33.3%, P = 0.001). Among potential HT candidates, 11 (68.8%) were discharged without advanced therapies and 4 received durable left ventricular assist device (25.0%). Importantly, 1-year survival was 100% for the 11 patients with follow-up. Thus, further work is critical to define appropriate candidates for HT from VA-ECMO while avoiding preemptive transplantation in those with otherwise favorable outcomes.

Venoarterial Extracorporeal Membrane Oxygenation in Cardiogenic Shock

Venoarterial extracorporeal membrane oxygenation has emerged as a viable treatment for patients in cardiogenic shock with biventricular failure and pulmonary dysfunction. Advances in pump and oxygenator technology, cannulation strategies, patient selection and management, and durable mechanical circulatory support have contributed to expanded utilization of this technology. However, challenges remain that require investigation to improve outcomes.

Clinical outcomes of temporary mechanical circulatory support as a direct bridge to heart transplantation: a nationwide Spanish registry

BACKGROUND

In Spain, listing for high-urgent heart transplantation is allowed for critically ill candidates not weanable from temporary mechanical circulatory support (T-MCS). We sought to analyse the clinical outcomes of this strategy.

METHODS AND RESULTS

We conducted a case-by-case, retrospective review of clinical records of 291 adult patients listed for high-urgent heart transplantation under temporary devices from 2010 to 2015 in 16 Spanish institutions. Survival after listing and adverse clinical events were studied. At the time of listing, 169 (58%) patients were supported on veno-arterial extracorporeal membrane oxygenation (VA-ECMO), 70 (24%) on temporary left ventricular assist devices (T-LVAD) and 52 (18%) on temporary biventricular assist devices (T-BiVAD). Seven patients transitioned from VA-ECMO to temporary ventricular assist devices while on the waiting list. Mean time on T-MCS was 13.1 ± 12.6 days. Mean time from listing to transplantation was 7.6 ± 8.5 days. Overall, 230 (79%) patients were transplanted and 54 (18.6%) died during MCS. In-hospital postoperative mortality after transplantation was 33.3%, 11.9% and 26.2% for patients bridged on VA-ECMO, T-LVAD and T-BiVAD, respectively (P = 0.008). Overall survival from listing to hospital discharge was 54.4%, 78.6% and 55.8%, respectively (P = 0.002). T-LVAD support was independently associated with a lower risk of death over the first year after listing (hazard ratio 0.52, 95% confidence interval 0.30-0.92). Patients treated with VA-ECMO showed the highest incidence rate of adverse clinical events associated with T-MCS.

CONCLUSION

Temporary devices may be used to bridge critically ill candidates directly to heart transplantation in a setting of short waiting list times, as is the case of Spain. In our series, bridging with T-LVAD was associated with more favourable outcomes than bridging with T-BiVAD or VA-ECMO.