Faculty Bibliography

CLINICAL CONDITION/UNASSIGNED:The authors present the case of a young man who presented with cardiogenic shock requiring venoarterial extracorporeal membrane oxygenation and microaxial flow pump complicated by acute spinal cord infarction (SCI) leading to bilateral lower extremity paraplegia. KEY QUESTIONS/UNASSIGNED:The key questions included the following: 1) What is the incidence and pathophysiology for SCI with mechanical circulatory support (MCS)?; 2) Which configurations of MCS carry a greater risk of SCI? How do we approach MCS escalation, recognizing that with each device we carry additive risk of complications?; 3) What data guide anticoagulation strategies for MCS?; and 4) What strategies can we implement to support patients who have suffered SCI from MCS? OUTCOME/RESULTS:Our patient was transitioned to a right ventricular assist device with Impella 5.5 as a bridge to therapy, and underwent cardiac transplantation 4 weeks after presentation with ongoing inpatient rehabilitation. TAKE-HOME MESSAGES/CONCLUSIONS:Contemporary MCS carries a small but significant risk of SCI which is often irreversible. More data are required to guide anticoagulation strategies for MCS and mitigate risk.

BACKGROUND/UNASSIGNED:Donation after circulatory death (DCD) with cardiopulmonary bypass for thoracoabdominal normothermic regional perfusion (TA-NRP) has led to increased use of donor hearts. Rejection rates and long-term survival outcomes are not known. METHODS/UNASSIGNED:A single-center retrospective cohort review of patients who underwent DCD heart transplantation from January 2020 to December 2023 was performed. Donor and recipient characteristics, operative characteristics, and posttransplantation outcomes were analyzed. Subgroup analysis comparing co-localized vs distant donors and recipients was performed. The primary end point was 1-year survival. Secondary end points included incidences of primary graft dysfunction (PGD), cardiac allograft vasculopathy (CAV), rejection rate, and overall mortality. Our TA-NRP protocol has remained the same, consisting of sternotomy, ligation of aortic arch vessels, establishment of cardiopulmonary bypass, reintubation, resuscitation of the heart, and cold static storage during transport. RESULTS/UNASSIGNED:< .005) ischemia times, without any other differences. CONCLUSIONS/UNASSIGNED:Outcomes after DCD heart transplantation using TA-NRP remain encouraging with acceptable rates of rejection, PGD, CAV, and survival at 1 year.

BACKGROUND:In the 2018 Organ Procurement and Transplantation Network donor heart allocation system, patients listed for re-transplantation due to cardiac allograft vasculopathy (CAV) are assigned to Status 4 unless hemodynamic criteria are met. We aim to examine waitlist outcomes of CAV patients among adult heart transplant candidates. METHODS:We examined waitlist mortality stratified by CAV and waitlist status among adult heart transplant candidates using Scientific Registry of Transplant Recipients data from 10/1/2018-11/1/2023. We analyzed waitlist mortality using Kaplan-Meier curves and doubly-robust Cox regressions adjusted for age, gender, sex, race, and dialysis. We compared CAV to non-CAV patients by initial waitlist status, first status of interest, and time-dependent status. RESULTS:Of 21,586 listed patients, 368 were listed for CAV. CAV patients were most often listed at Status 4 with lower proportions at Status 3/2/1 compared with non-CAV patients. Status 4 and Status 3 CAV candidates demonstrated higher than expected waitlist mortality compared to non-CAV counterparts (Status 4: HR 0.51, 95% CI 0.31-0.84; p < 0.01; Status 3: HR 0.61, 95% CI 0.23-1.64; p = 0.33) with similar mortality to non-CAV patients in Status 3 and 2, respectively (Status 4: HR 0.80, 95% CI 0.48-1.35; p = 0.4; Status 3: HR 1.07, 95% CI 0.40-2.86; p = 0.89). When stratifying by status tier, CAV waitlist patients ever listed at Status 4 and 3 had a higher probability of death compared to their non-CAV counterparts (Status 4: HR 1.99, 95% CI 1.20-3.31, p < 0.01; Status 3: HR 3.06, 95% CI 1.06-8.87, p = 0.04). CONCLUSIONS:After 2018, CAV patients had a higher risk of waitlist mortality at Status 4 and 3 compared to non-CAV patients. These results suggest that CAV patients are underprioritized in the current allocation system.

INTRODUCTION/UNASSIGNED:The 6-minute walk test (6MWT) is used to assess submaximal exercise capacity in clinical trials. Conducting the 6MWT can be challenging when patients cannot visit the clinic due to physical/travel limitations. This pilot study assessed the feasibility of conducting the 6MWT using wearable sensors for patients with transthyretin amyloid cardiomyopathy. METHODS/UNASSIGNED:Participants were enrolled in the phase 3 ATTRibute-CM trial. Sensors were positioned on patients' feet and lower back during the 6MWT. The 6-minute walk distance (6MWD) was compared with the distance measured by a trained observer during a concurrent conventional test. Pearson and concordance correlation coefficients were estimated. RESULTS/UNASSIGNED:Twelve participants from five centers participated; 11 had evaluable data. Mean 6MWD was 330.3 m (conventional method) and 335.1 m (wearable sensors); mean difference (SD) was 4.7 m (10.95). Pearson and concordance correlation coefficients for 6MWD were 0.998 (95% CI: 0.992-0.999) and 0.997 (95% CI: 0.991-0.999), respectively. CONCLUSIONS/UNASSIGNED:The 6MWD measured using wearable sensors and by the conventional method were closely correlated. Conducting the 6MWT with wearable sensors may be feasible and as reliable as the conventional method in a monitored clinic setting. Whether at-home 6MWD measured by wearable sensors correlates with in-clinic monitoring deserves further study. CLINICAL TRIAL REGISTRATION/UNASSIGNED:ClinicalTrials.gov identifier is NCT03860935.

PURPOSE/OBJECTIVE:Cardiac rehabilitation (CR) is beneficial in heart transplant and left ventricular assist device (LVAD) recipients, but patterns of attendance remain poorly understood. We describe CR adherence and cessation in this population. METHODS:We performed a retrospective review of heart transplant and LVAD recipients who attended ≥1 CR session at a tertiary medical center (2013-2022). Complete adherence was defined as attending 36 sessions. Primary reasons for cessation before 36 sessions were recorded. We compared post-operative complications, duration of hospitalization, and readmissions between participants with and without complete adherence using logistic and linear regressions. Among participants with complete adherence, we compared changes in metabolic equivalent of task (MET), exercise time, and peak oxygen uptake using paired sample t tests. RESULTS:There were 137 heart transplant and LVAD recipients (median age 56.9 years, 74% male) who attended CR. Among them, 91% either completed 36 CR sessions or <24 sessions. Among those without complete adherence (n = 74), 72% reported medical reasons, and 15% reported personal reasons for cessation. Compared to those who completed CR, those without complete adherence experienced more post-operative complications (44% vs 24%, P = .02) and major bleeding (23% vs 7%, P = .02) prior to CR. Participants with complete adherence experienced significant improvements in exercise time (142.5 seconds), MET (0.4), and peak oxygen uptake (1.4 mL/kg/min). CONCLUSIONS:Nearly half of heart transplant and LVAD recipients in CR completed all 36 sessions. Those with complete adherence experienced significant improvements in exercise measures, underscoring the important benefits of CR in this population.

INTRODUCTION/BACKGROUND:Patients with congenital heart disease (CHD) are at increased risk of cancer. In patients with CHD and advanced heart failure, isolated heart transplantation (HT) can be considered. In the overall HT population, immunosuppression after HT increases the risk of post-transplant malignancy (PTM). However, cancer outcomes among adult HT patients with CHD have not been investigated. METHODS:Patients aged ≥ 18 years who received HT between January 1, 2010 and December 31, 2021 were identified using the United Network for Organ Sharing (UNOS) registry. Patients with CHD were compared to those without. T primary outcome was a composite outcome of PTM or death due to malignancy. Multivariable Fine-Gray competing-risk regression was used to estimate the subhazard ratio (SHR) of primary and secondary outcomes. RESULTS:Of the total of 29717 patients with HT were included, 1017 (3.4%) had CHD. Patients with CHD were younger, more likely to be female, and have had prior cardiac surgery. After multivariable competing-risk regression, CHD was associated with a higher risk of the primary outcome (SHR 1.43, 95% CI 1.15-1.80). Among patients who developed PTM, the median time to diagnosis of first PTM (median 36 vs. 46 months, p = 0.027) was shorter in patients with CHD. Among patients with CHD, survival after PTM was significantly lower compared with patients without malignancy (HR 3.32, 95% CI 2.03-5.43). CONCLUSIONS:Among adult patients with HT, CHD was associated with an increased risk of PTM. Further investigation is warranted to identify risk factors and screening strategies for malignancy in this patient population.

BACKGROUND:Because of advances in medical treatment of heart failure, patients are living longer than in previous eras and may approach the need for advanced therapies, including heart transplantation, at older ages. This study assesses practices surrounding heart transplant in older adults (> 70 years) and examines short- and medium-term outcomes. METHODS AND RESULTS/RESULTS:This study is a retrospective analysis using the United Network for Organ Sharing (UNOS) database from 2010 to 2021. The absolute number of older adults being transplanted is increasing. Older adults were more likely to have had a prior malignancy or ischemic cardiomyopathy and less likely to be on extra-corporeal membrane oxygenation or have a high UNOS status prior to transplant. Mortality at 1-year was higher for older adults (27.8% vs. 23.4%), but at 5 years there was no significant difference (22.3% vs. 19.4%.). Older adults were more likely to die of malignancy or infection. Adults under 70 were more likely to die of cardiovascular causes or graft failure. There was less rejection in older adults. Mortality has not changed for older adults transplanted before versus after the 2018 UNOS allocation change. CONCLUSIONS:Carefully selected older adults may be considered for heart transplantation, given similar intermediate-term mortality.

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.

BACKGROUND/UNASSIGNED:Catheter ablation (CA) for ventricular tachycardia (VT) can be a useful treatment strategy, however, few studies have compared CA to medical therapy (MT) in the sarcoidosis population. OBJECTIVE/UNASSIGNED:To assess in-hospital outcomes and unplanned readmissions following CA for VT compared to MT in patients with sarcoidosis. METHODS/UNASSIGNED:Data was obtained from the Nationwide Readmissions Database between 2010 and 2019 to identify patients with sarcoidosis admitted for VT either undergoing CA or MT during elective and non-elective admission. Primary endpoints were a composite endpoint of inpatient mortality, cardiogenic shock, cardiac arrest and 30-day hospital readmissions. Procedural complications at index admission and causes of readmission were also identified. RESULTS/UNASSIGNED: = 0.343). The most common cause of readmission were ventricular arrhythmias (VA) in both groups, however, those undergoing elective CA were less likely to be readmitted for VA compared to non-elective CA. The most common complication in the CA group was cardiac tamponade (4.8 %). CONCLUSION/UNASSIGNED:VT ablation is associated with similar rates of 30-day readmission compared to MT and does not confer increased risk of harm with respect to inpatient mortality, cardiogenic shock or cardiac arrest. Further research is warranted to determine if a subgroup of sarcoidosis patients admitted with VT are better served with an initial conservative management strategy followed by VT ablation.

BACKGROUND:CARS (Cardiac Amyloidosis Registry Study) is a multicenter registry established in 2019 that includes patients with transthyretin (ATTR, wild-type and variant) and light chain (AL) cardiac amyloidosis (CA) evaluated at major amyloidosis centers between 1997 and 2025. CARS aims to describe the natural history of CA with attention to clinical and diagnostic variables at the time of diagnosis, real-world treatment patterns, and associated outcomes of patients in a diverse cohort that is more representative of the at-risk population than that described in CA clinical trials. METHODS AND RESULTS/RESULTS:This article describes the design and methodology of CARS, including procedures for data collection and preliminary results. As of February 2023, 20 centers in the United States enrolled 1415 patients, including 1155 (82%) with ATTR and 260 (18%) with AL CA. Among those with ATTR, wild-type is the most common ATTR (71%), and most of the 305 patients with variant ATTR have the p.V142I mutation (68%). A quarter of the total population identifies as Black. More individuals with AL are female (39%) compared to those with ATTR (13%). CONCLUSIONS:CARS will answer crucial clinical questions about CA natural history and permit comparison of different therapeutics not possible through current clinical trials. Future international collaboration will further strengthen the validity of observations of this increasingly recognized condition.