Characteristics and Outcomes of Recipients of Heart Transplant with Coronarvirus Disease 2019 Who Received Casirivimab Plus Imdevimab Infusion

Purpose

Heart transplant (HT) recipient are at increased risk of adverse outcomes following COVID-19 infection and may benefit from monoclonal antibody infusion to mitigate progression to clinically severe disease. The aim of this study is to describe the outcomes of HT patients who experienced mild to moderate coronavirus disease 2019 (COVID-19), with subsequent administration of casirivimab plus imdevimab administration.

Methods

A retrospective review of all HT recipients who were infected with COVID-19, and subsequently infused with monoclonal antibodies in a large academic medical center between January 1, 2021 to September 1, 2021.

Results

14 HT patients were included in the analysis. The median age was 57.5 (interquartile range [IQR], 41.5-64) years, 10 (71%) were men, and median time from HT was 3.48 (IQR, 1.00-11.82) years. Comorbid conditions included hypertension in 6 patients (43%), diabetes in 4 (29%), and chronic kidney disease in 6 (43%). Eight patients (57%) were previously vaccinated, predominantly with the Pfizer-BioNTech vaccine. Three participants (21%) were admitted after clinical progression of COVID-19. Among patients managed at the study institution, mycophenolate mofetil was discontinued in two patients (14%) and calcineurin inhibitor was maintained at previous levels in all fourteen patients (100%). Of the admitted patients, 1 was treated with high dose corticosteroids alone and 2 were treated with corticosteroids plus remdesivir. No patient required intubation. All 3 patients were discharged home and no patients in this cohort died.

Conclusion

In this single-center case series, HT patients with mild-moderate COVID-19 who were treated with monoclonal antibody infusion had a hospitalization rate of 21% and 100% survival. Further studies are required to optimize management of COVID-19 infection in the HT population.

De Novo Human Leukocyte Antigen Allosensitization in Heartmate 3 Versus Heartmate II Left Ventricular Assist Device Recipients

Left ventricular assist devices (LVADs) are associated with the development of antihuman leukocyte antigen (HLA) antibodies, which can create a challenge for future transplantation in these patients. The differential effects of Heartmate 3 (HM3) versus Heartmate II (HMII) on de novo HLA allosensitization remain unknown. Patients who underwent HMII or HM3 implantation and had no prior HLA antibodies by solid-phase assay (Luminex) testing were included in this study. Complement-dependent cytotoxicity (CDC) panel reactive antibody (PRA) levels and Luminex antibody profiles were followed until cardiac transplantation, device explantation, or death. Electronic medical records were reviewed to examine posttransplant outcomes. Thirty-eight HM3 and 34 HMII patients with complete data were followed for 1.5 ± 1.1 years on device support. HM3 and HMII groups had similar age at implant, female gender, ischemic heart failure etiology, bridge strategy at implant, as well as intraoperative and postoperative transfusion requirements. 39.5% of HM3 and 47.1% of HMII patients developed detectable HLA antibodies by Luminex testing (p = 0.516). Development of high-level (mean fluorescence intensity >10,000) antibodies was significantly lower in HM3 than HMII patients (5.3 vs. 20.6%, p = 0.049). CDC PRA testing showed fewer HM3 patients with a positive result (PRA > 0%) than HMII patients (39.4 vs. 70.0%, p = 0.015). Among transplanted patients, those who had developed de novo sensitization on LVAD support showed a trend toward incidence of moderate to severe grade rejection compared with unsensitized patients (23.8 vs. 4.8%, p = 0.078). HM3 is associated with lower risk of de novo HLA sensitization compared with HMII.

Impact of Pretransplant Malignancy on Heart Transplantation Outcomes: Contemporary United Network for Organ Sharing Analysis Amidst Evolving Cancer Therapies

BACKGROUND

An aging population and improved cancer survivorship have increased the number of individuals with treated malignancy who develop advanced heart failure. The benefits of heart transplantation (HT) in patients with a pretransplant malignancy (PTM) must be balanced against risks of posttransplant malignancy in the setting of immunosuppression.

METHODS

Adult patients in the United Network for Organ Sharing registry who received HT between January 1, 2010, and December 31, 2020 were included. Trends, patient characteristics, and posttransplant outcomes in HT recipients with PTM were evaluated.

RESULTS

From 2000 to 2020, the proportion of HT recipients with PTM increased from 3.2% to 8.2%. From 2010 to 2020, 2113 (7.7%) of 27 344 HT recipients had PTM. PTM was associated with higher rates of 1-year mortality after HT (11.9% versus 9.2%; adjusted hazard ratio, 1.25 [95% CI, 1.09-1.44], P=0.001), driven by increased mortality in patients with hematologic PTM (adjusted hazard ratio, 2.00 [95% CI, 1.61-2.48]; P<0.001). For recipients who survived the first year, 5-year survival was similar between patients with and without PTM. Rates of malignancy at 5-years posttransplant were higher in the PTM group (20.4% versus 13.1%; adjusted hazard ratio, 1.57 [95% CI, 1.38-1.79], P<0.001).

CONCLUSIONS

Prevalence of PTM in HT recipients nearly tripled over the past 2 decades. Patients with hematologic PTM were at increased risk of early mortality after HT. Patients with PTM were also at higher risk for posttransplant malignancy. Guidelines that reflect contemporary oncological care are needed to inform care of this heterogenous and expanding group of individuals.

How can we better inform our patients about post-heart transplantation survival? A conditional survival analysis

BACKGROUND

Conditional survival (CS) is a dynamic method of survival analysis that provides an estimate of how an individual's future survival probability changes based on time post-transplant, individual characteristics, and post-transplant events. This study sought to provide post-transplant CS probabilities for heart transplant recipients based on different prognostic variables and provide a discussion tool for the providers and the patients.

METHODS

Adult heart transplant recipients from January 1, 2004, through October 18, 2018, were identified in the UNOS registry. CS probabilities were calculated using data from Kaplan-Meier survival estimates.

RESULTS

CS probability exceeded actuarial survival probability at all times post-transplant. Women had similar short-term, but greater long-term CS than men at all times post-transplant (10-year CS 1.8-11.5% greater [95% CI 1.2-12.9]). Patients with ECMO or a surgical BiVAD had decreased survival at the time of transplant, but their CS was indistinguishable from all others by 1-year post-transplant. Rejection and infection requiring hospitalization during the first year were associated with a persistently decreased CS probability.

CONCLUSIONS

In this study, we report differential conditional survival outcomes based on time, patient characteristics, and clinical events post-transplant, providing a dynamic assessment of survival. The survival probabilities will better inform patients and clinicians of future outcomes.

Chronic intermittent intravenous immunoglobulin in heart transplant recipients with elevated donor-specific antibody levels

Donor-specific antibodies (DSA) are associated with antibody-mediated rejection (AMR) and poor patient survival. In heart transplant, the efficacy of intermittent intravenous immunoglobulin (IVIg) in reducing de novo DSA levels and treating AMR has not been characterized. We retrospectively studied a cohort of 19 patients receiving intermittent IVIg for elevated DSA and examined changes in DSA levels and graft function. Intermittent IVIg infusions were generally safe and well tolerated. Overall, 23 of 62 total DSA (37%) were undetectable after treatment, 21 DSA (34%) had MFI decrease by more than 25%, and 18 (29%) had MFI decrease by less than 25% or increase. The average change in MFI was -51% ± 71% (P < .001). Despite reductions in DSA, among the six patients (32%) with biopsy-confirmed AMR, left ventricular ejection fraction (LVEF) decreased in five (83%) and cardiac index (CI) decreased in three (50%). Conversely, LVEF increased in 91% and CI increased in 70% of biopsy-negative patients. All six AMR patients were readmitted during treatment, four for confirmed or suspected rejection. IVIg infusions may stabilize the allograft in patients with elevated DSA and negative biopsies, but once AMR has developed does not appear to improve allograft function despite decreasing DSA levels.

The use of telemedicine in cardiogenetics clinical practice during the COVID-19 pandemic

Background

The coronavirus disease 2019 (COVID-19) pandemic has necessitated the widespread adoption of telemedicine, and while many clinics have now re-established in-person patient visits, telemedicine is likely to continue to play an important role in health care delivery. In particular, the embrace of telemedicine presents an unprecedented opportunity through which to expand the reach of genetic counseling, i.e., telegenetics.

Purpose

The aim of this study was to examine the impact of COVID-19 on genetic counseling practices within the cardiogenetics clinics at a large academic center in New York City.

Methods

We retrospectively analyzed clinical characteristics of patients who were seen for cardiovascular genetic counseling visits pre-pandemic between April 1, 2019 through December 23, 2019 and during the pandemic between April 1, 2020 through December 23, 2020 at Columbia University Irving Medical Center. Genetic testing results were recorded for each encounter when available.

Results

Overall, 104 patients had a cardiovascular genetic counseling visit in 2019 compared to 132 patients in 2020 (Table). Only 6% (n=6) of visits in 2019 were remote telemedicine encounters whereas 80% (n=106) of visits in 2020 were telemedicine encounters. There was a significant increase in the number of family members seen for genetic counseling in 2020; in 2019 only 15% (n=16) of the patients seen for genetic counseling were family members of probands whereas this percentage increased to 34% in 2020 (n=45; p=0.002). In addition, in 2020 the geographic reach of genetic counseling extended far beyond New York state, reaching a total of 11 states as well as one patient in Puerto Rico (Figure). Genetic testing results were similar between the two years with 29% of patients found to be genotype positive in 2019 and 29% of patients genotype positive in 2020 (p=0.91). Notably, of those patients who underwent telemedicine visits and were sent genetic testing kits (n=106), 14% (n=15) did not return a sample.

Conclusions

In this study we found that despite the health care delivery barriers created by the COVID-19 pandemic, the use of telemedicine allowed us to not only continue seeing patients for cardiovascular genetic counseling visits but also to expand the reach of genetic counseling and testing beyond the geographical boundaries of our previous catchment area. Telegenetics offers patients and clinicians convenience and flexibility and has likely earned its permanent place in clinical practice. Future efforts are warranted to study the longer-term clinical impacts of telegenetics as well as to continue to improve telemedicine technology, with the ultimate aim of increasing patient access to personalized genomic medicine.

Funding Acknowledgement

Type of funding sources: None.

A Rare Case of Disseminated Tuberculosis and Hematological Malignancy in a Heart Transplant Recipient

A 77-year-old man who underwent a heart transplant 7 years ago presented with multiple bloody bowel movements. Endoscopic and histologic evaluation revealed chronic active ileitis, granulomatous inflammation, multinucleated giant cells, and a rare, equivocal acid-fast bacterium in the terminal ileum. Positive sputum cultures for Mycobacterium tuberculosis and acid-fast bacilli established a diagnosis of intestinal tuberculosis, and RIPE (rifabutin, isoniazid, pyrazinamide, ethambutol) therapy was initiated. Elevated IgG levels on quantitative immunoglobulin testing and a bone marrow biopsy specimen of ≥60% plasma cells confirmed the diagnosis of multiple myeloma that later transformed into its aggressive form, plasma cell leukemia. Induction chemotherapy was initiated; however, the patient experienced retroperitoneal bleeding and pancytopenias, limiting the continuation of chemotherapy, and as a result, the patient was transitioned to palliative care.

Cardiopulmonary exercise testing in patients with Cardiac Amyloidosis

BACKGROUND

Cardiac involvement and dysfunction are common in patients presenting with AL and ATTR Amyloidosis. Cardiopulmonary exercise testing (CPET) performance is the gold standard to quantify functional capacity.

PATIENTS AND METHODS

In this study, we evaluated CPET measurements in 41 patients with cardiac Amyloidosis and their correlation with current amyloid specific staging criteria.

RESULTS

In both AL and ATTR cardiac Amyloidosis, percent predicted peak VO2 is significantly reduced and correlates with biomarker abnormalities. The association of cardiac biomarkers with peak VO2 is stronger for AL Amyloidosis (NT-proBNP (r = -0.57, P=0.006), Troponin (r = -0.70, p < 0.001) than ATTR (NT-proBNP (r = -0.4, P = 0.04) and Troponin (r = -0.57, P = 0.002) despite lower left ventricular mass in the former, suggesting that this may be further evidence for light chain toxicity in AL amyloidosis.

CONCLUSION

Our findings suggest further evidence for AL toxicity.

Exception Status Listing in the New Adult Heart Allocation System: A New Solution to an Old Problem?

BACKGROUND

One of the goals of the revised 6-tiered US adult heart allocation policy was to improve risk stratification of patients to lower exception status utilization for transplant listing. We sought to define the characteristics and outcomes of waitlisted patients using exception status and to examine region- and center-level differences in utilization of exception status in the new heart allocation system.

METHODS

This retrospective cohort analysis of the United Network for Organ Sharing database included adult waitlisted patients for heart transplant between October 18, 2018, and June 30, 2020, in the United States, stratified by use of exception status versus standard criteria.

RESULTS

Out of 6351 patients, 1907 (30.0%) were waitlisted under exception status. Patients using exception status were more likely to have a nonischemic cause of heart failure, blood type O, United Network for Organ Sharing status 2 at listing and were less likely to have a durable left ventricular assist device at listing. Exception status utilization varied significantly between and within United Network for Organ Sharing regions. Listing by exception criteria was associated with a significantly higher incidence of heart transplantation compared with listing by standard criteria (hazard ratio, 1.25 [1.15-1.38], P<0.001), without increased risk of death or delisting for worsening clinical status (hazard ratio, 0.83 [0.65-1.05], P=0.12) after multivariable adjustment.

CONCLUSIONS

The status tiers of the new heart allocation system may not fully capture medical urgency and complexity of waitlisted patients as assessed by transplant physicians and review committees and may limit the ability to develop a heart allocation score.

Extracorporeal photopheresis and its role in heart transplant rejection: prophylaxis and treatment

Heart transplantation is the gold standard therapeutic option for select patients with end-stage heart failure. Unfortunately, successful long-term outcomes of heart transplantation can be hindered by immune-mediated rejection of the cardiac allograft, specifically acute cellular rejection, antibody-mediated rejection, and cardiac allograft vasculopathy. Extracorporeal photopheresis is a cellular immunotherapy that involves the collection and treatment of white blood cells contained in the buffy coat with a photoactive psoralen compound, 8-methoxy psoralen, and subsequent irradiation with ultraviolet A light. This process is thought to cause DNA and RNA crosslinking, ultimately leading to cell destruction. The true mechanism of therapeutic action remains unknown. In the last three decades, extracorporeal photopheresis has shown promising results and is indicated for a variety of conditions. The American Society for Apheresis currently recommends the use of extracorporeal photopheresis for the treatment of cutaneous T-cell lymphoma, scleroderma, psoriasis, pemphigus vulgaris, atopic dermatitis, graft-versus-host disease, Crohn's disease, nephrogenic systemic fibrosis, and solid organ rejection in heart, lung, and liver transplantation. In this review, we aim to explore the proposed effects of extracorporeal photopheresis and to summarize published data on its use as a prophylactic and therapy in heart transplant rejection.

Characteristics and Outcomes of Recipients of Heart Transplant With Coronavirus Disease 2019

Importance

Recipients of heart transplant (HT) may be at increased risk of adverse outcomes attributable to infection with coronavirus disease 2019 (COVID-19) because of multiple comorbidities and clinically significant immunosuppression.

Objective

To describe the characteristics, treatment, and outcomes of recipients of HT with COVID-19.

Design, Setting, and Participants

This case series from a single large academic heart transplant program in New York, New York, incorporates data from between March 1, 2020, and April 24, 2020. All recipients of HT followed up by this center who were infected with COVID-19 were included.

Interventions

Heart transplant and a confirmed diagnosis of COVID-19.

Main Outcomes and Measures

The primary measure was vital status at end of study follow-up. Secondary measures included patient characteristics, laboratory analyses, changes to immunosuppression, and treatment administered for COVID-19.

Results

Twenty-eight patients with HT received a confirmed diagnosis of COVID-19. The median age was 64.0 (interquartile range [IQR], 53.5-70.5) years, 22 (79%) were men, and the median time from HT was 8.6 (IQR, 4.2-14.5) years. Comorbid conditions included hypertension in 20 patients (71%), diabetes in 17 patients (61%), and cardiac allograft vasculopathy in 16 patients (57%). Twenty-two participants (79%) were admitted for treatment, and 7 (25%) required mechanical ventilation. Most (13 of 17 [76%]) had evidence of myocardial injury (median high-sensitivity troponin T, 0.055 [IQR, 0.0205-0.1345] ng/mL) and elevated inflammatory biomarkers (median peak high-sensitivity C-reactive protein, 11.83 [IQR, 7.44-19.26] mg/dL; median peak interleukin 6, 105 [IQR, 38-296] pg/mL). Among patients managed at the study institution, mycophenolate mofetil was discontinued in 16 patients (70%), and 6 (26%) had a reduction in the dose of their calcineurin inhibitor. Treatment of COVID-19 included hydroxychloroquine (18 patients [78%]), high-dose corticosteroids (8 patients [47%]), and interleukin 6 receptor antagonists (6 patients [26%]). Overall, 7 patients (25%) died. Among 22 patients (79%) who were admitted, 11 (50%) were discharged home, 4 (18%) remain hospitalized at the end of the study, and 7 (32%) died during hospitalization.

Conclusions and Relevance

In this single-center case series, COVID-19 infection was associated with a case fatality rate of 25% in recipients of HT. Immunosuppression was reduced in most of this group of patients. Further study is required to evaluate the optimal approach to management of COVID-19 infection in the HT population.

How to create an autism friendly hospital environment

Introduction

Children with Autism Spectrum Disorder (ASD) struggle with communication, sensory sensitivities and social interaction. These difficulties can make hospital visits challenging. Every child with ASD is unique, and as such, some children can do well in clinical settings with minimal supports while others may require environmental modifications to achieve optimal care. ASD is prevalent worldwide and cultural differences can lead to varied care. Several hospitals, including Boston Medical Center in USA and Sidra Medicine and Research Center in Qatar, have attempted to address these challenges by developing strategies to create an ‘Autism Friendly’ environment.

Objectives

This workshop will 1. Describe the 4 domains of an “Autism Friendly” environment 2. Describe practical steps for successful implementation of interventions and modifications to consider based on setting and culture.

Methods

Didactic section 1 will describe the 4 domains for greating an ‘Autism Friendly environment’. Didactic section 2 will describe implementation in an inpatient and outpatient setting focusing on modifications based on environmental differences. These didactic presentations will be followed by a hands on, interactive section where participants will break out in small groups to learn specific implementation skills.

Results

Participants will learn how to improve care offered to children with ASD during hospital visits. Participants will develop the skills to implement similar interventions in their home institutions.

Conclusions

Hospitals can create an Autism Friendly environment by using 4 domains of intervention which could help improve provider skills and patient and family experience.

Remote Monitoring of Heart Transplant Recipients during the COVID-19 Pandemic

Purpose

The COVID-19 pandemic created significant challenges in monitoring heart transplant (HT) recipients for rejection due to efforts to minimize contact with the hospital setting. The aim of this study was to evaluate the safety and efficacy of transitioning HT patients to home phlebotomy and a monitoring protocol based on gene expression profiling (GEP) and donor derived cell free DNA (ddcfDNA).

Methods

A single-center cohort study that prospectively enrolled consecutive HT patients who were transitioned to a remote monitoring protocol employing home phlebotomy and non-invasive surveillance for rejection. Patients were enrolled starting at 2 months post-HT. Positive GEP values were defined as ≥32 (up to 6 months post-HT) and ≥34 (> 6 months post-HT). A positive ddcfDNA score was defined as >0.12%. A positive biopsy was defined as grade ≥1B/1R

Results

246 HT patients were enrolled and followed for a minimum of 3 months. Mean age was 56±14, 71.5% were male, and median time from transplant was 2.7 years. The average distance of patients from the hospital was 25.6 miles. 359 blood tests were drawn for detection of GEP and ddcfDNA and 102 biopsies performed (Figure). Among 32 patients who had negative results on both tests and had a biopsy, 0 had a positive biopsy. Of 25 patients who had positive results on both tests and had a biopsy, 3 (12%) had a positive biopsy. The biopsy positivity rate in patients who were GEP+/ddcfDNA- was 6% and in patients who were GEP-/ddcfDNA+ was 8%. None of the positive biopsies were associated with hemodynamic compromise. 15 (6%) of patients were admitted due to allograft rejection during the study period. There were no deaths.

Conclusion

Using a remote monitoring protocol with home phlebotomy and noninvasive rejection surveillance was feasible and safe in HT recipients. In this cohort, the combination of negative GEP and ddcfDNA scores was accurate at predicting a lack of allograft rejection.

Transition of a Large Tertiary Heart Failure Program in Response to the COVID-19 Pandemic: Changes That Will Endure

The coronavirus disease 2019 (COVID-19) pandemic imposed severe restrictions on traditional methods of patient care. During the pandemic, the heart failure program at New York-Presbyterian Hospital in New York, NY rapidly and comprehensively transitioned its care delivery model and administrative organization to conform to a new healthcare environment while still providing high-quality care to a large cohort of patients with heart failure, heart transplantation, and left ventricular assist device. In addition to the widespread adoption of telehealth, our program restructured outpatient care, initiating a shared clinic model and introducing a comprehensive remote monitoring program to manage patients with heart failure and heart transplant. All conferences, including administrative meetings, support groups, and educational seminars were converted to teleconferencing platforms. Following the peak of COVID-19, many of the new changes have been maintained, and the program structure will be permanently altered as a lasting effect of this pandemic. In this article, we review the details of our program's transition in the face of COVID-19 and highlight the programmatic changes that will endure.

United network for organ sharing outcomes after heart transplantation for al compared to ATTR cardiac amyloidosis

Light-chain (AL) cardiac amyloidosis (CA) has a worse prognosis than transthyretin (ATTR) CA. In this single-center study, we compared post-heart transplant (OHT, orthotopic heart transplantation) survival for AL and ATTR amyloidosis, hypothesizing that these differences would persist post-OHT. Thirty-nine patients with CA (AL, n = 18; ATTR, n = 21) and 1023 non-amyloidosis subjects undergoing OHT were included. Cox proportional hazards modeling was used to evaluate the impact of amyloid subtype and era (early era: from 2001 to 2007; late era: from 2008 to 2018) on survival post-OHT. Survival for non-amyloid patients was greater than ATTR (P = .034) and AL (P < .001) patients in the early era. One, 3-, and 5-year survival rates were higher for ATTR patients than AL patients in the early era (100% vs 75%, 67% vs 50%, and 67% vs 33%, respectively, for ATTR and AL patients). Survival in the non-amyloid cohort was 87% at 1 year, 81% at 3 years, and 76% at 5 years post-OHT. In the late era, AL and ATTR patients had unadjusted 1-year, 3-year, and 5-year survival rates of 100%, which was comparable to non-amyloid patients (90% vs 84% vs 81%). Overall, these findings demonstrate that in the current era, differences in post-OHT survival for AL compared to ATTR are diminishing; OHT outcomes for selected patients with CA do not differ from non-amyloidosis patients.

Gut microbial diversity, inflammation, and oxidative stress are associated with tacrolimus dosing requirements early after heart transplantation

Introduction

Effective tacrolimus (TAC) dosing is hampered by complex pharmacokinetics and significant patient variability. The gut microbiome, a key mediator of endotoxemia, inflammation and oxidative stress in advanced heart failure (HF) patients, is a possible contributor to interindividual variations in drug efficacy. The effect of alterations in the gut microbiome on TAC dosing requirements after heart transplant (HT) has not been explored.

Methods

We enrolled 24 patients (mean age = 55.8 ±2.3 years) within 3 months post-HT. Biomarkers of endotoxemia ((lipopolysaccharide (LPS)), inflammation (tumor necrosis factor-α (TNF-α)) and oxidative stress (8,12-iso-Isoprostane F-2alpha-VI) were measured in 16 blood samples. 22 stool samples were analyzed using 16S rRNA sequencing. TAC dose and serum trough level were measured at the time of stool and blood collection. TAC doses were reported in mg/kg/day and as level-to-dose (L/D) ratio, and categorized as ≤ vs. > median.

Results

The median TAC dose was 0.1 mg/kg/day and L/D ratio was 100.01. Above the median daily weight-based TAC dose was associated with higher gut microbial alpha diversity (p = 0.03); similarly, TNF-α and 8,12-iso-Isoprostane F-2alpha-VI levels were lower and LPS levels were higher in the above median TAC group, although these findings were only marginally statistically significant and dependent on BMI adjustment. We observed n = 37 taxa to be significantly enriched among patients with > median TAC dose (all FDR<0.05), several of which are potential short-chain fatty acid producers with anti-inflammatory properties, including taxa from the family Subdoligranulum.

Conclusions

Our pilot study observed gut microbial alpha diversity to be increased while inflammation and oxidative stress were reduced among patients requiring higher TAC doses early after HT.

Mechanical Circulatory Support Device Utilization and Heart Transplant Waitlist Outcomes in Patients With Restrictive and Hypertrophic Cardiomyopathy

BACKGROUND

Patients with restrictive cardiomyopathy (RCM) and hypertrophic cardiomyopathy (HCM) generally are considered poor candidates for mechanical circulatory support devices (MCSDs) and often not able to be bridged mechanically to heart transplantation. This study characterized MCSD utilization and transplant waitlist outcomes in patients with RCM/HCM under the current allocation system and discusses changes in the era of the new donor allocation system.

METHODS AND RESULTS

Patients waitlisted from 2006 to 2016 in the United Network for Organ Sharing registry were stratified by RCM/HCM versus other diagnoses. MCSD utilization and waitlist duration were analyzed by propensity score models. Waitlist outcomes were assessed by cumulative incidence functions with competing events. Predictors of waitlist mortality or delisting for worsening status in patients with RCM/HCM were identified by proportional hazards model. Of 30 608 patients on the waitlist, 5.1% had RCM/HCM. Patients with RCM/HCM had 31 fewer waitlist days (P<0.01) and were ≈26% less likely to receive MCSD (P<0.01). Cumulative incidence of waitlist mortality was similar between cohorts; however, patients with RCM/HCM had higher incidence of heart transplantation. Predictors of waitlist mortality or delisting for worsening status in patients with RCM/HCM without MCSD support included estimated glomerular filtration rate <60 mL/min per 1.73 m², pulmonary capillary wedge pressure >20 mm Hg, inotrope use, and subjective frailty.

CONCLUSIONS

Patients with RCM/HCM are less likely to receive MCSD but have similar waitlist mortality and slightly higher incidence of transplantation compared with other patients. The United Network for Organ Sharing RCM/HCM risk model can help identify patients who are at high risk for clinical deterioration and in need of expedited heart transplantation.

Impact of Bridge to Transplantation With Continuous-Flow Left Ventricular Assist Devices on Posttransplantation Mortality

BACKGROUND

Bridge to transplantation (BTT) with left ventricular assist devices (LVADs) is a mainstay of therapy for heart failure in patients awaiting heart transplantation (HT). Criteria for HT listing do not differ between patients medically managed and those mechanically bridged to HT. The objectives of the present study were to evaluate the impact of BTT with LVAD on posttransplantation survival, to describe differences in causes of 1-year mortality in medically and mechanically bridged patients, and to evaluate differences in risk factors for 1-year mortality between those with and those without LVAD at the time of HT.

METHODS

Using the United Network of Organ Sharing database, we identified 5486 adult, single-organ HT recipients transplanted between 2008 and 2015. Patients were propensity matched for likelihood of LVAD at the time of HT. Kaplan-Meier survival estimates were used to assess the impact of BTT on 1- and 5-year mortality. Logistic regression analysis was used to evaluate the odds ratio of 1-year mortality for patients BTT with LVAD compared with those with medical management across clinically significant variables at various thresholds.

RESULTS

Early mortality was higher in mechanically bridged patients: 9.5% versus 7.2% mortality at 1 year (P<0.001). BTT patients incurred an increased risk of 1-year mortality with an estimated glomerular filtration rate of 40 to 60 mL·min^-1·1.73 m^-2 (odds ratio, 1.69; P=0.003) and <40 mL·min^-1·1.73 m^-2 (odds ratio, 2.16; P=0.005). A similar trend was seen in patients with a body mass index of 25 to 30 kg/m² (odds ratio, 1.88; P=0.024) and >30 kg/m² (odds ratio, 2.11; P<0.001). When patients were stratified by BTT status and the presence of risk factors, including age >60 years, estimated glomerular filtration rate <40 mL·min^-1·1.73 m^-2, and body mass index >30 kg/m², there were significant differences in 1-year mortality between medium- and high-risk medically and mechanically bridged patients, with 1-year mortality in high-risk BTT patients at 17.6% compared with 10.4% in high-risk medically managed patients.

CONCLUSIONS

Bridge to HT with LVAD, although necessary because of organ scarcity and capable of improving wait list survival, confers a significantly higher risk of early posttransplantation mortality. Patients bridged with mechanical support may require more careful consideration for transplant eligibility after LVAD placement.

Myocardial Contraction Fraction Predicts Cardiovascular Events in Patients With Hypertrophic Cardiomyopathy and Normal Ejection Fraction

BACKGROUND

Myocardial contraction fraction (MCF), the ratio of left ventricular stroke volume to myocardial volume, is a novel parameter that can distinguish between pathologic and physiologic hypertrophy. However, its prognostic value in hypertrophic cardiomyopathy (HCM) has never been examined. The objective was to determine if MCF is associated with functional capacity and predicts adverse cardiovascular outcomes in patients with HCM and normal left ventricular ejection fraction (LVEF).

METHODS AND RESULTS

We conducted a prospective cohort study of 137 patients with HCM and LVEF ≥55%. Patients were followed for 2.7 ± 2.5 years. We examined association of MCF with New York Heart Association (NYHA) functional class and a composite outcome of embolic stroke, heart transplantation, and cardiac death. We performed time-to-event analysis with the use of Cox proportional hazards modeling and stepwise elimination. The average age was 52 ± 18 years. The average MCF was 26 ± 11%. MCF was inversely correlated with NYHA functional class (P = .001). A total of 20 subjects experienced an outcome event with an event rate of 5.6% per patient-year. MCF independently predicted the outcome (adjusted hazard ratio 0.50 per 10% increase, 95% confidence interval 0.28-0.90, adjusted P = .02).

CONCLUSIONS

In patients with HCM and normal LVEF, MCF is associated with functional capacity and independently predicts adverse cardiovascular outcomes.