Deep learning to detect left ventricular structural abnormalities in chest X-rays.

BACKGROUND AND AIMS: Early identification of cardiac structural abnormalities indicative of heart failure is crucial to improving patient outcomes. Chest X-rays (CXRs) are routinely conducted on a broad population of patients, presenting an opportunity to build scalable screening tools for structural abnormalities indicative of Stage B or worse heart failure with deep learning methods. In this study, a model was developed to identify severe left ventricular hypertrophy (SLVH) and dilated left ventricle (DLV) using CXRs. METHODS: A total of 71 589 unique CXRs from 24 689 different patients completed within 1 year of echocardiograms were identified. Labels for SLVH, DLV, and a composite label indicating the presence of either were extracted from echocardiograms. A deep learning model was developed and evaluated using area under the receiver operating characteristic curve (AUROC). Performance was additionally validated on 8003 CXRs from an external site and compared against visual assessment by 15 board-certified radiologists. RESULTS: The model yielded an AUROC of 0.79 (0.76-0.81) for SLVH, 0.80 (0.77-0.84) for DLV, and 0.80 (0.78-0.83) for the composite label, with similar performance on an external data set. The model outperformed all 15 individual radiologists for predicting the composite label and achieved a sensitivity of 71% vs. 66% against the consensus vote across all radiologists at a fixed specificity of 73%. CONCLUSIONS: Deep learning analysis of CXRs can accurately detect the presence of certain structural abnormalities and may be useful in early identification of patients with LV hypertrophy and dilation. As a resource to promote further innovation, 71 589 CXRs with adjoining echocardiographic labels have been made publicly available.

Evolving Strategies for the Management of Obstructive Hypertrophic Cardiomyopathy.

For many years, treatment of hypertrophic cardiomyopathy (HCM) has focused on non-disease-specific therapies. Cardiac myosin modulators (ie, mavacamten and aficamten) reduce the pathologic actin-myosin interactions that are characteristic of HCM, leading to improved cardiac energetics and reduction in hypercontractility. Several recently published randomized clinical trials have demonstrated that mavacamten improves exercise capacity, left ventricular outflow tract obstruction and symptoms in patients with obstructive HCM and may delay the need for septal-reduction therapy. Long-term data in real-world populations will be needed to fully assess the safety and efficacy of mavacamten. Importantly, HCM is a complex and heterogeneous disease, and not all patients will respond to mavacamten; therefore, careful patient selection and shared decision making will be necessary in guiding the use of mavacamten in obstructive HCM.

The Association Between Preoperative Pectoralis Muscle Quantity and Outcomes After Cardiac Transplantation.

BACKGROUND: Sarcopenia is underappreciated in advanced heart failure and is not routinely assessed. In patients receiving a left ventricular assist device, preoperative sarcopenia, defined by using computed-tomography (CT)-derived pectoralis muscle-area index (muscle area indexed to body-surface area), is an independent predictor of postoperative mortality. The association between preoperative sarcopenia and outcomes after heart transplant (HT) is unknown. OBJECTIVES: The primary aim of this study was to determine whether preoperative sarcopenia, diagnosed using the pectoralis muscle-area index, is an independent predictor of days alive and out of the hospital (DAOHs) post-transplant. METHODS: Patients who underwent HT between January, 2018, and June, 2022, with available preoperative chest CT scans were included. Sarcopenia was diagnosed as pectoralis muscle-area index in the lowest sex-specific tertile. The primary endpoint was DAOHs at 1 year post-transplant. RESULTS: The study included 169 patients. Patients with sarcopenia (n = 55) had fewer DAOHs compared to those without sarcopenia, with a median difference of 17 days (320 vs 337 days; P = 0.004). Patients with sarcopenia had longer index hospitalizations and were also more likely to be discharged to a facility other than home. In a Poisson regression model, sarcopenia was a significant univariable and the strongest multivariable predictor of DAOHs at 1 year (parameter estimate = -0.17, 95% CI -0.19 to -14; P = < 0.0001). CONCLUSIONS: Preoperative sarcopenia, diagnosed using the pectoralis muscle-area index, is an independent predictor of poor outcomes after HT. This parameter is easily measurable from commonly obtained preoperative CT scans and may be considered in transplant evaluations.

The Hemodynamic Effects of Aortic Regurgitation in Patients Supported by a HeartMate 3 Left Ventricular Assist Device.

BACKGROUND: Aortic regurgitation (AR) is a common complication following left ventricular assist device (LVAD) implantation. We evaluated the hemodynamic implications of AR in patients with HeartMate 3 (HM3) LVAD at baseline and in response to speed changes. METHODS AND RESULTS: Clinically stable outpatients supported by HM3 who underwent a routine hemodynamic ramp test were retrospectively enrolled in this analysis. Patients were stratified based on the presence of at least mild AR at baseline speed. Hemodynamic and echocardiographic parameters were compared between the AR and non-AR groups. Sixty-two patients were identified. At the baseline LVAD speed, 29 patients (47%) had AR, while 33 patients (53%) did not. Patients with AR were older and supported on HM3 for a longer duration. At baseline speed, all hemodynamic parameters were similar between the groups including central venous pressure, pulmonary capillary wedge pressure, pulmonary arterial pressures, cardiac output and index, and pulmonary artery pulsatility index (p > 0.05 for all). During the subacute assessment, AR worsened in some, but not all, patients, with increases in LVAD speed. There were no significant differences in 1-year mortality or hospitalization rates between the groups, however, at 1-year, ≥ moderate AR and right ventricular failure (RVF) were detected in higher rates among the AR group compared to the non-AR group (45% vs. 0%; p < 0.01, and 75% vs. 36.8%; p = 0.02, respectively). CONCLUSIONS: In a cohort of stable outpatients supported with HM3 who underwent a routine hemodynamic ramp test, the presence of mild or greater AR did not impact the ability of HM3 LVADs to effectively unload the left ventricle during early subacute assessment. Although the presence of AR did not affect mortality and hospitalization rates, it resulted in higher rates of late hemodynamic-related events in the form of progressive AR and RVF.

Impact of Age of Heart Transplant Program on Patient Survival and Post-Transplant Outcomes.

BACKGROUND: The relationship between age of a heart transplant (HT) program and outcomes has not been explored. METHODS: We performed a retrospective cohort analysis of the United Network for Organ Sharing database of all adult HTs between 2009 and 2019. For each patient, we created a variable that corresponded to program age: new (<5), developing (≥5 but <10) and established (≥10) years. RESULTS: Of 20 997 HTs, 822 were at new, 908 at developing, and 19 267 at established programs. Patients at new programs were significantly more likely to have history of cigarette smoking, ischemic cardiomyopathy, and prior sternotomy. These programs were less likely to accept organs from older donors and those with a history of hypertension or cigarette use. As compared to patients at new programs, transplant patients at established programs had less frequent rates of treated rejection during the index hospitalization (HR 0.43 [95% CI, 0.36-0.53] p < 0.001) and at 1 year (HR 0.58 [95% CI, 0.49-0.70], p < 0.001), less frequently required pacemaker implantations (HR 0.50 [95% CI, 0.36-0.69], p < 0.001), and less frequently required dialysis (HR 0.66 [95% CI, 0.53-0.82], p < 0.001). However, there were no significant differences in short- or long-term survival between the groups (log-rank p = 0.24). CONCLUSION: Patient and donor selection differed between new, developing, and established HT programs but had equivalent survival. New programs had increased likelihood of treated rejection, pacemaker implantation, and need for dialysis. Standardized post-transplant practices may help to minimize this variation and ensure optimal outcomes for all patients.

A change of heart: Characteristics and outcomes of multiple cardiac retransplant recipients.

BACKGROUND: Among heart transplant (HT) recipients who develop advanced graft dysfunction, cardiac re-transplantation may be considered. A smaller subset of patients will experience failure of their second allograft and undergo repeat re-transplantation. Outcomes among these individuals are not well-described. METHODS: Adult and pediatric patients in the United Network for Organ Sharing (UNOS) registry who received HT between January 1, 1990 and December 31, 2020 were included. RESULTS: Between 1990 and 2020, 90 individuals received a third HT and three underwent a fourth HT. Recipients were younger than those undergoing primary HT (mean age 32 years). Third HT was associated with significantly higher unadjusted rates of 1-year mortality (18% for third HT vs. 13% for second HT vs. 9% for primary HT, p < .001) and 10-year mortality (59% for third HT vs. 42% for second HT vs. 37% for primary HT, p < .001). Mortality was highest amongst recipients aged >60 years and those re-transplanted for acute graft failure. Long-term rates of CAV, rejection, chronic dialysis, and hospitalization for infection were also higher. CONCLUSIONS: Third HT is associated with higher morbidity and mortality than primary HT. Further consensus is needed regarding appropriate organ stewardship for this unique subgroup.

Long-term outcomes for pediatric heart transplant recipients transitioning to adult care teams.

BACKGROUND: There are limited data evaluating the success of a structured transition plan specifically for pediatric heart transplant (HT) recipients following their transfer of care to an adult specialist. We sought to identify risk factors for poor adherence, graft failure, and mortality following the transfer of care to adult HT care teams. METHODS: We retrospectively reviewed all patients who underwent transition from the pediatric to adult HT program at our center between January 2011 and June 2021. Demographic characteristics, comorbid conditions, and psychosocial history were collected at the time of HT, the time of transition, and the most recent follow-up. Adverse events including mortality, graft rejection, infection, and renal function were also captured before and after the transition. RESULTS: Seventy-two patients were identified (54.1% male, 54.2% Caucasian). Mean age at the time of transition was 23 years after a median of 11.6 years in the pediatric program. The use of calcineurin inhibitors was associated with reduced mortality (HR .04, 95% CI .0-.6, p = .015), while prior psychiatric hospitalization (HR 45.3, 95% CI, 6.144-333.9, p = .0001) was associated with increased mortality following transition. Medication nonadherence and young age at the time of transition were markers for high-risk individuals prior to the transition of care. CONCLUSIONS: Transition of HT recipients from a pediatric program to an adult program occurs during a vulnerable time of emerging adulthood, and we have identified risk factors for mortality following transition. Development of a formalized transition plan with a large multidisciplinary team with focused attention on high-risk patients, including those with psychiatric comorbidities, may favorably influence outcomes.

Utility of a fusion protein T-cell co-stimulation blocker Belatacept in heart transplant recipients: Real world experience from a high volume center.

BACKGROUND: Belatacept (BTC), a fusion protein, selectively inhibits T-cell co-stimulation by binding to the CD80 and CD86 receptors on antigen-presenting cells (APCs) and has been used as immunosuppression in adult renal transplant recipients. However, data regarding its use in heart transplant (HT) recipients are limited. This retrospective cohort study aimed to delineate BTC's application in HT, focusing on efficacy, safety, and associated complications at a high-volume HT center. METHODS: A retrospective cohort study was conducted of patients who underwent HT between January 2017 and December 2021 and subsequently received BTC as part of their immunosuppressive regimen. Twenty-one HT recipients were identified. Baseline characteristics, history of rejection, and indication for BTC use were collected. Outcomes included renal function, graft function, allograft rejection and mortality. Follow-up data were collected through December 2023. RESULTS: Among 776 patients monitored from January 2017 to December 2021 21 (2.7%) received BTC treatment. Average age at transplantation was 53 years (± 12 years), and 38% were women. BTC administration began, on average, 689 [483, 1830] days post-HT. The primary indications for BTC were elevated pre-formed donor-specific antibodies in highly sensitized patients (66.6%) and renal sparing (23.8%), in conjunction with reduced calcineurin inhibitor dosage. Only one (4.8%) patient encountered rejection within a year of starting BTC. Graft function by echocardiography remained stable at 6 and 12 months posttreatment. An improvement was observed in serum creatinine levels (76.2% of patients), decreasing from a median of 1.58 to 1.45 (IQR [1.0-2.1] to [1.1-1.9]) over 12 months (p = .054). eGFR improved at 3 and 6 months compared with 3 months pre- BTC levels; however, this was not statistically significant (p = .24). Treatment discontinuation occurred in seven patients (33.3%) of whom four (19%) were switched back to full dose CNI. Infections occurred in 11 patients (52.4%), leading to BTC discontinuation in 4 patients (19%). CONCLUSION: In this cohort, BTC therapy was used as alternative immunosuppression for management of highly sensitized patients or for renal sparing. BTC therapy when combined with CNI dose reduction resulted in stabilization in renal function as measured through renal surrogate markers, which did not, however, reach statistical significance. Patients on BTC maintained a low rejection rate and preserved graft function. Infections were common during BTC therapy and were associated with medication pause/discontinuation in 19% of patients. Further randomized studies are needed to assess the efficacy and safety of BTC in HT recipients.

Unplanned hospital readmissions following HeartMate 3 implantation: Readmission rates, causes, and impact on survival.

BACKGROUND: Hospital readmissions following left ventricular assist device (LVAD) remain a frequent comorbidity, associated with decreased quality of life and increased resources utilization. This study sought to determine causes, predictors, and impact on survival of hospitalizations during HeartMate 3 (HM3) support. METHODS: All patients implanted with HM3 between November 2014 to December 2019 at Columbia University Irving Medical Center were consecutively enrolled in the study. Demographics and clinical characteristics from the index admission and the first outpatient visit were collected and used to estimate 1-year and 900-day readmission-free survival and overall survival. Multivariable analysis was performed for subsequent readmissions. RESULTS: Of 182 patients who received a HM3 LVAD, 167 (92%) were discharged after index admission and experienced 407 unplanned readmissions over the median follow up of 727 (interquartile range (IQR): 410.5, 1124.5) days. One-year and 900-day mean cumulative number of all-cause unplanned readmissions was 0.43 (95%CI, 0.36, 0.51) and 1.13 (95%CI, 0.99, 1.29). The most frequent causes of rehospitalizations included major infections (29.3%), bleeding (13.2%), device-related (12.5%), volume overload (7.1%), and other (28%). One-year and 900-day survival free from all-cause readmission was 38% (95%CI, 31-46%) and 16.6% (95%CI, 10.3-24.4%). One-year and 900-day freedom from 2, 3, and ≥4 readmissions were 60.7%, 74%, 74.5% and 26.2%, 33.3%, 41.3%. One-year and 900-day survival were unaffected by the number of readmissions and remained >90%. Male sex, ischemic etiology, diabetes, lower serum creatinine, longer duration of index hospitalization, and a history of readmission between discharge and the first outpatient visit were associated with subsequent readmissions. CONCLUSIONS: Unplanned hospital readmissions after HM3 are common, with infections and bleeding accounting for the majority of readmissions. Irrespective of the number of readmissions, one-year survival remained unaffected.

Clonal hematopoiesis of indeterminate potential and outcomes after heart transplantation: A multicenter study.

Cardiac allograft vasculopathy (CAV) is a leading cause of late graft failure and mortality after heart transplantation (HT). Sharing some features with atherosclerosis, CAV results in diffuse narrowing of the epicardial coronaries and microvasculature, with consequent graft ischemia. Recently, clonal hematopoiesis of indeterminate potential (CHIP) has emerged as a risk factor for cardiovascular disease and mortality. We aimed to investigate the relationship between CHIP and posttransplant outcomes, including CAV. We analyzed 479 HT recipients with stored DNA samples at 2 high-volume transplant centers, Vanderbilt University Medical Center and Columbia University Irving Medical Center. We explored the association between the presence of CHIP mutations with CAV and mortality after HT. In this case-control analysis, carriers of CHIP mutations were not at increased risk of CAV or mortality after HT. In a large multicenter genomics study of the heart transplant population, the presence of CHIP mutations was not associated with an increased risk of CAV or posttransplant mortality.

PCSK9 inhibitors safely and effectively lower LDL after heart transplantation: a systematic review and meta-analysis.

Coronary allograft vasculopathy (CAV) continues to afflict a high number of heart transplant (HT) recipients, and elevated LDL is a key risk factor. Many patients cannot tolerate statin medications after HT; however, data for alternative agents remains scarce. To address this key evidence gap, we evaluated the safety and efficacy of the PCSK9i after HT through systematic review and meta-analysis. We searched Medline, Cochrane Central, and Scopus from the earliest date through July 15th, 2021. Citations were included if they were a report of PCSK9i use in adults after HT and reported an outcome of interest. Outcomes included change in LDL cholesterol from baseline, incidence of adverse events, and evidence of CAV. Changes from baseline and outcome incidences were pooled using contemporary random-effects model methodologies. A total of six studies including 97 patients were included. Over a mean follow-up of 13 months (range 3-21), PCSK9i use lowered LDL by 82.61 mg/dL (95% CI - 119.15 to - 46.07; I2 = 82%) from baseline. Serious adverse drug reactions were rarely reported, and none was attributable to the PCSK9i therapy. Four studies reported stable calcineurin inhibitor levels during PCSK9i initiation. One study reported outcomes in 33 patients with serial coronary angiography and intravascular ultrasound, and PCSK9i were associated with stable coronary plaque thickness and lumen area. One study reported on immunologic safety, showing no DSA development within 1 month of therapy. Preliminary data suggest that long-term PCSK9i therapy is safe, significantly lowers LDL, and may attenuate CAV after HT. Additional study on larger cohorts is warranted to confirm these findings.

The impact of pre-existing hematologic disorders on morbidity and mortality following heart transplantation: Focus on early graft dysfunction.

BACKGROUND: Heart transplantation (HT) is the gold standard therapy for advanced heart failure, providing excellent long-term outcomes. However, postoperative outcomes are limited by bleeding, infections, and primary graft dysfunction (PGD) that contribute to early mortality after HT. HT candidates with pre-existing hematologic disorders, bleeding, and clotting, may represent a higher risk population. We assessed the short- and long-term outcomes of patients with pre-existing hematologic disorders undergoing HT. METHODS AND RESULTS: Medical records of all adult patients who received HT from January 2010 to December 2019 at our institution were retrospectively reviewed. Hematologic disorders were identified via chart review and adjudicated by a board-certified hematologist. Inverse probability weighting and multivariable models were used to adjust for potential pretransplant confounders. Four hundred and ninety HT recipients were included, of whom 29 (5.9%) had a hematologic disorder. Hematologic disorders were associated with severe PGD requiring mechanical circulatory support (aOR 3.15 [1.01-9.86]; p = .049), postoperative infections (aOR 2.93 [1.38-6.23]; p = .01), and 3-year acute cellular rejection (ACR) (≥1R/1B) (aSHR 2.06 [1.09-3.87]; p = .03). There was no difference in in-hospital mortality (aOR 1.23 [.20-7.58], p = .82) or 3-year mortality (aHR 1.58 [.49-5.12], p = .44). CONCLUSIONS: Patients with hematologic disorders undergoing HT are at increased risk of severe PGD, postoperative infections, and ACR, while in-hospital and 3-year mortality remain unaffected.

Early post-transplant leukopenia in heart transplant recipients and its impact on outcomes.

BACKGROUND: Leukopenia in the early period following heart transplantation (HT) is not well-studied. The aim of this study was to evaluate risk factors for the development of post-transplant leukopenia and its consequences for HT recipients. METHODS: Adult patients at a large-volume transplant center who received HT between January 1, 2010 and December 31, 2020 were included. The incidence of leukopenia (WBC ≤3 × 103 /µL) in the first 90-days following HT, individual risk factors, and its effect on 1-year outcomes were evaluated. RESULTS: Of 506 HT recipients, 184 (36%) developed leukopenia within 90-days. Median duration of the first leukopenia episode was 15.5 days (IQR 8-42.5 days). Individuals who developed leukopenia had lower pre-transplant WBC counts compared to those who did not (6.1 × 103 /µL vs. 6.9 × 103 /µL, p = .02). Initial immunosuppressive and infectious chemoprophylactic regimens were not significantly different between groups. Early leukopenia was associated with a higher mortality at 1-year (6.6% vs. 2.1%, p = .008; adjusted HR 3.0) and an increased risk of recurrent episodes. Rates of infection and rejection were not significantly different between the two groups. CONCLUSIONS: Leukopenia in the early period following HT is common and associated with an increased risk of mortality. Further study is needed to identify individuals at highest risk for leukopenia prior to transplant and optimize immunosuppressive and infectious chemoprophylactic regimens for this subgroup.

The utilization of molecular microscope in management of heart transplant recipients in the era of noninvasive monitoring.

INTRODUCTION: Monitoring for graft rejection is a fundamental tenet of post-transplant follow-up. In heart transplantation (HT) in particular, rejection has been traditionally assessed with endomyocardial biopsy (EMB). EMB has potential complications and noted limitations, including interobserver variability in interpretation. Additional tests, such as basic cardiac biomarkers, cardiac imaging, gene expression profiling (GEP) scores, donor-derived cell-free DNA (dd-cfDNA) and the novel molecular microscope diagnostic system (MMDx) have become critical tools in rejection surveillance beyond standard EMB. METHODS: This paper describes an illustrative case followed by a review of MMDx within the context of other noninvasive screening modalities for rejection. CONCLUSIONS: We suggest MMDx be used to assist with early detection of rejection in cases of discordance between EMB and other noninvasive studies.

How Does COVID-19 Affect the Heart?

PURPOSE OF REVIEW: Cardiac consequences occur in both acute COVID-19 and post-acute sequelae of COVID-19 (PASC). Here, we highlight the current understanding about COVID-19 cardiac effects, based upon clinical, imaging, autopsy, and molecular studies. RECENT FINDINGS: COVID-19 cardiac effects are heterogeneous. Multiple, concurrent cardiac histopathologic findings have been detected on autopsies of COVID-19 non-survivors. Microthrombi and cardiomyocyte necrosis are commonly detected. Macrophages often infiltrate the heart at high density but without fulfilling histologic criteria for myocarditis. The high prevalences of microthrombi and inflammatory infiltrates in fatal COVID-19 raise the concern that recovered COVID-19 patients may have similar but subclinical cardiac pathology. Molecular studies suggest that SARS-CoV-2 infection of cardiac pericytes, dysregulated immunothrombosis, and pro-inflammatory and anti-fibrinolytic responses underlie COVID-19 cardiac pathology. The extent and nature by which mild COVID-19 affects the heart is unknown. Imaging and epidemiologic studies of recovered COVID-19 patients suggest that even mild illness confers increased risks of cardiac inflammation, cardiovascular disorders, and cardiovascular death. The mechanistic details of COVID-19 cardiac pathophysiology remain under active investigation. The ongoing evolution of SARS-CoV-2 variants and vast numbers of recovered COVID-19 patients portend a burgeoning global cardiovascular disease burden. Our ability to prevent and treat cardiovascular disease in the future will likely depend on comprehensive understanding of COVID-19 cardiac pathophysiologic phenotypes.

Increased Opportunities for Transplantation for Women in the New Heart Allocation System.

BACKGROUND: Historically, women have had less access to advanced heart failure therapies, including temporary and permanent mechanical circulatory support and heart transplantation (HT), with worse waitlist and post-transplant survival compared with men. This study evaluated for improvement in sex differences across all phases of HT in the 2018 allocation system. METHODS AND RESULTS: The United Network for Organ Sharing registry was queried to identify adult patients (≥18 years) listed for HT from October 18, 2016, to October 17, 2018 (old allocation), and from October 18, 2018, to October 18, 2020 (new allocation). The outcomes of interest included waitlist survival, pretransplant use of temporary and durable mechanical circulatory support, rates of HT, and post-transplant survival. There were 15,629 patients who were listed for HT and included in this analysis; 7745 (2039 women, 26.3%) in the new and 7875 patients (2074 women, 26.3%) in the old allocation system. When compared with men in the new allocation system, women were more likely to have lower priority United Network for Organ Sharing status at time of transplant, and less likely to be supported by an intra-aortic balloon pump (27.1% vs 32.2%, P < .001), with no difference in the use of venoarterial extracorporeal membrane oxygenation (5.5% vs 6.3%, P = .28). Despite these findings, when transplantation was viewed in the context of risk for death or delisting, the cumulative incidence of transplant within 6 months of listing was higher in women than men in the new allocation system (62.4% vs 54.9%, P < .001) with no differences in post-transplant survival. When comparing women in the old with the new allocation system, the distance traveled for organ procurement was 187.5 ± 207.0 miles vs 272.8 ± 233.7 miles (P < .001). CONCLUSIONS: Although the use of temporary mechanical circulatory support in women remains lower than in men in the new allocation system, more women are being transplanted with comparable waitlist and post-transplant outcomes as men. Broader sharing may be making its greatest impact on improving transplant opportunities for women.

Impact of socioeconomic deprivation on evaluation for heart transplantation at an urban academic medical center.

INTRODUCTION: For patients with advanced heart failure, socioeconomic deprivation may impede referral for heart transplantation (HT). We examined the association of socioeconomic deprivation with listing among patients evaluated at our institution and compared this against the backdrop of our local community. METHODS: We conducted a retrospective cohort study of patients evaluated for HT between January 2017 and December 2020. Patient demographics and clinical characteristics were recorded. Block group-level area deprivation index (ADI) decile was obtained at each patient's home address and Socioeconomic Status (SES) index was determined by patient zip code. RESULTS: In total, 400 evaluations were initiated; one international patient was excluded. Among this population, 111 (27.8%) were women, 219 (54.9%) were White, 94 (23.6%) Black, and 59 (14.8%) Hispanic. 248 (62.2%) patients were listed for transplant. Listed patients had significantly higher SES index and lower ADI compared to those who were not listed. However, after adjustment for clinical factors, ADI and SESi were not predictive of listing. Similarly, patient sex, race, and insurance did not influence the likelihood of listing for HT. Notably, the distribution of the referral cohort based on ADI deciles was not reflective of our center's catchment area, indicating opportunities for improving access to transplant for disadvantaged populations. CONCLUSIONS: Although socioeconomic deprivation did not predict listing in our analysis, we recognize the need for broader outreach to combat upstream bias that prevents patients from being referred for HT.

The impact of pre-transplant weight loss on survival following cardiac transplantation.

BACKGROUND: Significant weight loss due to cardiac cachexia is an independent predictor of mortality in many heart failure (HF) clinical trials. The impact of significant weight loss while on the waitlist for heart transplant (HT) has yet to be studied with respect to post-transplant survival. METHODS: Adult HT recipients from 2010 to 2021 were identified in the UNOS registry. Patients who experienced an absolute weight change from the time of listing to transplant were included and classified into two groups by percent weight loss from time of listing to time of transplant using a cut-off of 10%. The primary endpoint was 1-year survival following HT. RESULTS: 5951 patients were included in the analysis, of whom 763 (13%) experienced ≥10% weight loss from the time of listing to transplant. Weight loss ≥ 10% was associated with reduced 1-year post-transplant survival (86.9% vs. 91.0%, long-rank p = .0003). Additionally, weight loss ≥ 10% was an independent predictor of 1-year mortality in a multivariable model adjusting for significant risk factors (adjusted HR 1.23, 95% CI 1.04-1.46). In secondary analyses, weight loss ≥ 10% was associated with reduced 1-year survival independent of hospitalized status at time of transplant as well as obesity status at listing (i.e., body mass index [BMI] < 30 kg/m2 and BMI ≥ 30 kg/m2 ). CONCLUSIONS: Preoperative weight loss ≥ 10% is associated with reduced survival in patients listed for HT. Nutrition interventions prior to transplant may prove beneficial in this population.

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.

Letermovir for cytomegalovirus prophylaxis in high-risk heart transplant recipients.

Letermovir is a novel agent for the prevention of cytomegalovirus (CMV) infection and disease that, unlike traditional CMV DNA polymerase inhibitors, does not carry the risk of myelosuppression. The purpose of this study was to evaluate the safety, efficacy, and clinical application of letermovir for CMV prophylaxis in heart transplant (HT) recipients. Between November 1, 2019, and October 1, 2021, at a single, tertiary care hospital, 17 HT recipients were initiated on letermovir due to leukopenia while on valganciclovir. Fifteen (88%) had high-risk mismatch (CMV D+/R-). Median time on letermovir was 5 months (interquartile range, 2-8 months.) At the end of the study period, nine of 17 patients (52.9%) were still on letermovir and four of the 17 (23.5%) had successfully completed the prophylaxis window on letermovir and been switched to the pre-emptive strategy. One patient developed clinically significant CMV viremia in the setting of being unable to obtain medication due to insurance barriers but was later successfully restarted on letermovir. One patient was unable to tolerate letermovir due to symptoms of headache and myalgias. Two patients developed low-level non-clinically significant CMV viremia and were switched back to valacyclovir. All patients had tacrolimus dosages reduced at time of letermovir initiation to minimize the risk of supratherapeutic tacrolimus concentration. One patient required hospitalization due to symptomatic tacrolimus toxicity. For HT recipients who cannot tolerate valganciclovir, letermovir presents an alternative for CMV prophylaxis. Close monitoring for breakthrough CMV and calcineurin inhibitor levels is necessary. Larger studies are required to further delineate its use and help provide further evidence of its safety and efficacy.