Comparing outcomes for infiltrative and restrictive cardiomyopathies under the new heart transplant allocation system

Clinical Outcomes for Heart-Alone and Multiorgan Transplant Under the New Heart Allocation Policy Era

BACKGROUND

In October 2018, a new heart transplant allocation policy was implemented in the United States to address inequalities. Under the new policy, some patient outcomes for patients with heart transplant have improved; however, outcomes of multiorgan transplants combined with heart remain unclear.

METHODS

We examined the waitlist mortality, time to transplant, and posttransplant survival for all patients listed between 2013 and 2022 for multiorgan transplants with heart (n=3798) and compared the old policy era to the new policy era using cumulative incident curves and multivariable Cox regression models. Cumulative incidence curves also compared multiorgan transplants to patients listed for heart alone (n=31 840) under the new policy era.

RESULTS

Patients awaiting multiorgan transplants had higher use of intra-aortic balloon pumps (4.7% versus 11%) and extracorporeal membrane oxygenation support (2.4% versus 4.9%) in the new policy era. Under the new policy, despite receiving transplants sooner (n=2200 transplants, hazard ratio [HR], 1.74 [95% CI, 1.59-1.91]), patients who received multiorgan transplants had no change in waitlist mortality (n=340 deaths, HR, 1.06 [95% CI, 0.84-1.34]) compared with the old policy era. The rate of death post-multiorgan transplant was significantly higher in incidence curves under the new policy compared with the old policy era (log-rank P=0.02). However, in multivariable Cox models, the risk of death post-multiorgan transplant was similar under the new policy (n=287 deaths, HR, 1.11 [95% CI, 0.87-1.41]) compared with the old policy era.

CONCLUSIONS

Under the new policy, waitlist deaths have decreased for patients awaiting heart alone, but not for those awaiting multiorgan transplants. Post-transplant survival remains lower for patients who underwent multiorgan transplant (compared with heart-alone transplant), with no change under the new policy.

Amyloidosis and Heart Transplantation in a New Era

BACKGROUND

The prognosis in patients with advanced cardiac amyloidosis (CA) remains poor.

OBJECTIVES

We sought to describe survival post heart transplantation (HT) in amyloid compared with non-amyloid recipients, highlight waitlist times within the new allocation system across three Organ Procurement and Transplantation Network (OPTN) regions, and describe multiorgan transplantation (MOT) in hereditary amyloidosis.

METHODS

This is a retrospective review of end-stage CA patients who underwent HT at Mayo Clinic from January 2007 to December 2020. Wait time was compared in the new versus old OPTN allocation era starting December 18, 2018 by Wilcoxon rank sum test. All-cause mortality for those with and without CA was compared using Kaplan-Meier estimates with log rank analysis, censoring December 16, 2022.

RESULTS

Fifty-five patients with CA underwent HT between 2007 and 2020, 8 light chain amyloidosis (AL) (14.5%), 28 hereditary transthyretin (ATTRv) (50.9%), 17 wildtype transthyretin (ATTRwt) (30.9%), and 2 hereditary apolipoprotein A1 (AApoA1) amyloidosis patients (3.6%). No significant difference in overall survival post-transplant was seen in amyloid compared with non-amyloid (p = 0.816). Median time to HT was shorter in the new system, 45 days (IQR 24, 78) versus 174 days (IQR 76.5, 483.5), p = 0.006. There was a decline in MOT in hereditary amyloidosis over time with the concomitant rise in disease-targeted therapies.

CONCLUSIONS

HT survival in CA patients was similar to non-amyloid patients. The new allocation system benefits this cohort with shorter wait times. There is less MOT in hereditary amyloidosis with increased utilization of disease-targeted therapy.

Diagnosis and Management of Cardiac Sarcoidosis: A Scientific Statement From the American Heart Association

Cardiac sarcoidosis is an infiltrative cardiomyopathy that results from granulomatous inflammation of the myocardium and may present with high-grade conduction disease, ventricular arrhythmias, and right or left ventricular dysfunction. Over the past several decades, the prevalence of cardiac sarcoidosis has increased. Definitive histological confirmation is often not possible, so clinicians frequently face uncertainty about the accuracy of diagnosis. Hence, the likelihood of cardiac sarcoidosis should be thought of as a continuum (definite, highly probable, probable, possible, low probability, unlikely) rather than in a binary fashion. Treatment should be initiated in individuals with clinical manifestations and active inflammation in a tiered approach, with corticosteroids as first-line treatment. The lack of randomized clinical trials in cardiac sarcoidosis has led to treatment decisions based on cohort studies and consensus opinions, with substantial variation observed across centers. This scientific statement is intended to guide clinical practice and to facilitate management conformity by providing a framework for the diagnosis and management of cardiac sarcoidosis.

Diagnostic and management strategies in cardiac sarcoidosis

Cardiac sarcoidosis (CS) is increasingly recognized in the context of with otherwise unexplained electrical or structural heart disease due to improved diagnostic tools and awareness. Therefore, clinicians require improved understanding of this rare but fatal disease to care for these patients. The cardinal features of CS, include arrhythmias, atrio-ventricular conduction delay and cardiomyopathy. In addition to treatments tailored to these cardiac manifestations, immunosuppression plays a key role in active CS management. However, clinical trial and consensus guidelines are limited to guide the use of immunosuppression in these patients. This review aims to provide a practical overview to the current diagnostic challenges, treatment approach, and future opportunities in the field of CS.

Waitlist Outcomes in Candidates With Rare Causes of Heart Failure After Implementation of the 2018 French Heart Allocation Scheme

BACKGROUND

In 2018, an algorithm-based allocation system for heart transplantation (HT) was implemented in France. Its effect on access to HT of patients with rare causes of heart failure (HF) has not been assessed.

METHODS

In this national study, including adults listed for HT between 2018 and 2020, we analyzed waitlist and posttransplant outcomes of candidates with rare causes of HF (restrictive cardiomyopathy [RCM], hypertrophic cardiomyopathy, and congenital heart disease). The primary end point was death on the waitlist or delisting for clinical deterioration. Secondary end points included access to HT and posttransplant mortality. The cumulative incidence of waitlist mortality estimated with competing risk analysis and incidence of transplantation were compared between diagnosis groups. The association of HF cause with outcomes was determined by Fine-Gray or Cox models.

RESULTS

Overall, 1604 candidates were listed for HT. At 1 year postlisting, 175 patients met the primary end point and 1040 underwent HT. Candidates listed for rare causes of HF significantly differed in baseline characteristics and had more frequent score exceptions compared with other cardiomyopathies (31.3%, 32.0%, 36.4%, and 16.7% for patients with hypertrophic cardiomyopathy, RCM, congenital heart disease, and other cardiomyopathies). The cumulative incidence of death on the waitlist and probability of HT were similar between diagnosis groups (P=0.17 and 0.40, respectively). The adjusted risk of death or delisting for clinical deterioration did not significantly differ between candidates with rare and common causes of HF (subdistribution hazard ratio (HR): hypertrophic cardiomyopathy, 0.51 [95% CI, 0.19-1.38]; P=0.18; RCM, 1.04 [95% CI, 0.42-2.58]; P=0.94; congenital heart disease, 1.82 [95% CI, 0.78-4.26]; P=0.17). Similarly, the access to HT did not significantly differ between causes of HF (hypertrophic cardiomyopathy: HR, 1.18 [95% CI, 0.92-1.51]; P=0.19; RCM: HR, 1.19 [95% CI, 0.90-1.58]; P=0.23; congenital heart disease: HR, 0.76 [95% CI, 0.53-1.09]; P=0.14). RCM was an independent risk factor for 1-year posttransplant mortality (HR, 2.12 [95% CI, 1.06-4.24]; P=0.03).

CONCLUSIONS

Our study shows equitable waitlist outcomes among HT candidates whatever the indication for transplantation with the new French allocation scheme.

Heart transplant outcomes in restrictive cardiomyopathy: UNOS registry analysis of the last three decades

Background

Restrictive cardiomyopathy (RCM) comprises diverse etiologies with overall poor prognosis. Emerging therapies have significantly impacted some of these entities. However, these therapies may have limited impact in the end-stages and have only recently become available. We sought to assess outcomes before and after transplant in the RCM population stratified into 3 distinct time periods from the recent era.

Methods

Retrospective analysis of the United Network of Organ Sharing registry (n = 62,709) for all patients transplanted between 1987 and March 1, 2022, were stratified by RCM status with 1157 patients with RCM. Populations were grouped temporally into classic (1987-2000), contemporary (2000-2013), and current (2014-2022) eras. Multiorgan and repeat transplants were excluded from the analysis. Baseline demographics, listing status, hemodynamics, donor information, and life support methods were compared using Kruskal-Wallis and Pearson's tests. Longitudinal survival was assessed via Kaplan-Meier survival analysis. Univariate and multivariate analyses using Cox modeling and competing outcomes analyses were performed.

Results

RCM patients were older, female, with older donors and longer ischemic times (p < 0.001). There were no significant differences in overall survival compared to the non-RCM population, however, with increased transplant rates. Amyloidosis and chemotherapy/radiation portend the worst prognosis but have shorter waitlist times and up-trending survival in the current era.

Conclusions

RCM represents a small but significant population of those requiring heart transplant. RCM transplant outcomes appear to be improving across all subsets with shorter wait times and better survival. Early recognition is important to help mitigate adverse outcomes.

Impact of the 2018 UNOS Heart Transplant Policy Changes on Patient Outcomes

In 2018, the United Network for Organ Sharing implemented a 6-tier allocation policy to replace the prior 3-tier system. Given increasing listings of critically ill candidates for heart transplantation and lengthening waitlist times, the new policy aimed to better stratify candidates by waitlist mortality, shorten waiting times for high priority candidates, add objective criteria for common cardiac conditions, and further broaden sharing of donor hearts. There have been significant shifts in cardiac transplantation practices and patient outcomes following the implementation of the new policy, including changes in listing practices, waitlist time and mortality, transplant donor characteristics, post-transplantation outcomes, and mechanical circulatory support use. This review aims to highlight emerging trends in United States heart transplantation practice and outcomes following the implementation of the 2018 United Network for Organ Sharing heart allocation policy and to address areas for future modification.

Evolving Characteristics of Heart Transplantation Donors and Recipients: JACC Focus Seminar

Although the burden of end-stage heart failure continues to increase, the number of available organs for heart transplantation (HT) remains inadequate. The HT community has been challenged to find ways to expand the number of donor hearts available. Recent advances include use of hearts from donors infected with hepatitis C virus as well as other previously underutilized donors, including those with left ventricular dysfunction, of older age, and with a history of cocaine use. Concurrently, emerging trends in HT surgery include donation after circulatory death, ex vivo normothermic heart perfusion, and controlled hypothermic preservation, which may enable procurement of organs from farther distances and prevent early allograft dysfunction. Contemporary HT recipients have also evolved in light of the 2018 revision to the U.S. heart allocation policy. This focus seminar discusses recent trends in donor and recipient phenotypes and management strategies for successful HT, as well as evolving areas and future directions.

State-of-the-art review on management of end-stage heart failure in amyloidosis: transplant and beyond

Cardiac involvement occurs in light-chain (AL), transthyretin wild-type (wtATTR), and hereditary (hATTR) amyloidosis; other types of amyloidosis account for < 5% of all cardiac amyloidosis (CA). CA can present subclinically on screening, insidiously with symptoms such as exertional dyspnea, or abruptly as cardiogenic shock. Initially, CA patients were thought to be poor candidates for transplant due to short long-term survival; however, there is a marked improvement in heart and multi-organ transplant outcomes over the past 10 years with newer treatments and improvements in support with temporary and durable mechanical circulatory support while awaiting transplant. Patients with AL CA were reported to have worse post-OHT outcomes than patients with ATTR CA, but this gap is quickly closing with improved patient selection, novel chemotherapeutics, and perhaps with selected use of bone marrow transplantation. Waitlist mortality and transplantation rates have markedly improved for CA after the United Network for Organ Sharing (UNOS) policy change in October 2018. In this review, we will evaluate contemporary data from the last 5 years on advances in the field of transplantation and mechanical circulatory support in this patient population.

Outcomes after heart transplantation in patients with cardiac sarcoidosis

Background

The number of patients with sarcoidosis requiring heart transplantation (HT) is increasing. The aim of this study was to evaluate outcomes of isolated HT in patients with sarcoid cardiomyopathy and compare them to recipients with non‐ischaemic restrictive or dilated cardiomyopathy.

Methods and results

Adult HT recipients were identified in the UNOS Registry between 1990 and 2020. Patients were grouped according to diagnosis. The cumulative incidences for the all‐cause mortality and rejection were compared using Fine and Gray model analysis, accounting for re‐transplantation as a competing risk. Rejection was evaluated using logistic regression analysis. We also reviewed characteristics and outcomes of all HT recipients with previous diagnosis of sarcoid cardiomyopathy from a single centre. A total of 30 160 HT recipients were included in the present study (n = 239 sarcoidosis, n = 1411 non‐ischaemic restrictive cardiomyopathy, and n = 28 510 non‐ischaemic dilated cardiomyopathy). During a total of 194 733 patient‐years, all‐cause mortality at the latest follow‐up was not significantly different when comparing sarcoidosis to non‐ischaemic dilated cardiomyopathy [adjusted subhazard ratio (aSHR) 1.46, 95% confidence intervals (CIs): 0.9–2.4, P = 0.12] or restrictive cardiomyopathy (aSHR 1.12, 95% CI: 0.65–1.95, P = 0.67). Accordingly, multivariable analysis suggested that 1 year mortality was not significantly different between sarcoidosis and non‐ischaemic dilated cardiomyopathy (aSHR 1.56, 95% CI: 0.9–2.7, P = 0.12) or restrictive cardiomyopathy (aSHR 1.15, 95% CI: 0.61–2.18, P = 0.66). No differences were observed regarding 30 day mortality, treated and hospitalized acute rejection, and 30 day death from graft failure after HT. Thirty‐day mortality did not improve significantly in more recent HT eras whereas there was a trend towards improved 1 year mortality in the latest HT era (P = 0.06). Data from the single‐centre case review showed excellent long‐term outcomes with sirolimus‐based immunosuppression.

Conclusions

Short‐term and long‐term post HT outcomes among patients with sarcoid cardiomyopathy are similar to those with common types of non‐ischaemic cardiomyopathy.

Sarcoidosis-Related Cardiomyopathy: Current Knowledge, Challenges, and Future Perspectives State-of-the-Art Review

The prevalence of sarcoidosis-related cardiomyopathy is increasing. Sarcoidosis impacts cardiac function through granulomatous infiltration of the heart, resulting in conduction disease, arrhythmia, and/or heart failure. The diagnosis of cardiac sarcoidosis (CS) can be challenging and requires clinician awareness as well as differentiation from overlapping diagnostic phenotypes, such as other forms of myocarditis and arrhythmogenic cardiomyopathy. Clinical manifestations, extracardiac involvement, histopathology, and advanced cardiac imaging can all lend support to a diagnosis of CS. The mainstay of therapy for CS is immunosuppression; however, no prospective clinical trials exist to guide management. Patients may progress to developing advanced heart failure or ventricular arrhythmia, for which ventricular assist device therapies or heart transplantation may be considered. The existing knowledge gaps in CS call for an interdisciplinary approach to both patient care and future investigation to improve mechanistic understanding and therapeutic strategies.

Pathophysiology and Therapeutic Approaches to Cardiac Amyloidosis

Often considered a rare disease, cardiac amyloidosis is increasingly recognized by practicing clinicians. The increased rate of diagnosis is in part due the aging of the population and increasing incidence and prevalence of cardiac amyloidosis with advancing age, as well as the advent of noninvasive methods using nuclear scintigraphy to diagnose transthyretin cardiac amyloidosis due to either variant or wild type transthyretin without a biopsy. Perhaps the most important driver of the increased awareness is the elucidation of the biologic mechanisms underlying the pathogenesis of cardiac amyloidosis which have led to the development of several effective therapies with differing mechanisms of actions. In this review, the mechanisms underlying the pathogenesis of cardiac amyloidosis due to light chain (AL) or transthyretin (ATTR) amyloidosis are delineated as well as the rapidly evolving therapeutic landscape that has emerged from a better pathophysiologic understanding of disease development.