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.

Comparative Analysis of Ischemia-Reperfusion Injury in Heart Transplantation: A Single-Center Study Evaluating Conventional Ice-Cold Storage versus the Paragonix SherpaPak Cardiac Transport System.

BACKGROUND: Since the 2018 allocation system change in heart transplantation (HT), ischemic times have increased, which may be associated with peri-operative and post-operative complications. This study aimed to compare ischemia reperfusion injury (IRI) in hearts preserved using ice-cold storage (ICS) and the Paragonix SherpaPak TM Cardiac Transport System (CTS). METHODS: From January 2021 to June 2022, consecutive endomyocardial biopsies from 90 HT recipients were analyzed by a cardiac pathologist in a single-blinded manner: 33 ICS and 57 CTS. Endomyocardial biopsies were performed at three-time intervals post-HT, and the severity of IRI manifesting histologically as coagulative myocyte necrosis (CMN) was evaluated, along with graft rejection and graft function. RESULTS: The incidence of IRI at weeks 1, 4, and 8 post-HT were similar between the ICS and CTS groups. There was a 59.3% statistically significant reduction in CMN from week 1 to 4 with CTS, but not with ICS. By week 8, there were significant reductions in CMN in both groups. Only 1 out of 33 (3%) patients in the ICS group had an ischemic time >240 mins, compared to 10 out of 52 (19%) patients in the CTS group. During the follow-up period of 8 weeks to 12 months, there were no significant differences in rejection rates, formation of de novo donor-specific antibodies and overall survival between the groups. CONCLUSION: The CTS preservation system had similar rates of IRI and clinical outcomes compared to ICS despite longer overall ischemic times. There is significantly more recovery of IRI in the early post operative period with CTS. This study supports CTS as a viable option for preservation from remote locations, expanding the donor pool.

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.

Evolution of Mechanical Circulatory Support for advanced heart failure.

This comprehensive review highlights the significant advancements in Left Ventricular Assist Device (LVAD) therapy, emphasizing its evolution from the early pulsatile flow systems to the cutting-edge continuous-flow devices, particularly the HeartMate 3 (HM3) LVAD. These advancements have notably improved survival rates, reduced complications, and enhanced the quality of life (QoL) for patients with advanced heart failure. The dual role of LVADs, as a bridge-to-transplantation and destination therapy is discussed, highlighting the changing trends and policies in their application. The marked reduction in hemocompatibility-related adverse events (HRAE) with the HM3 LVAD, compared to previous models signifies ongoing progress in the field. Challenges such as managing major infections are discussed, including innovative solutions like energy transfer systems aimed at eliminating external drivelines. It explores various LVAD-associated complications, including HRAE, infections, hemodynamic-related adverse events, and cardiac arrhythmias, and underscores emerging strategies for predicting post-implantation outcomes, fostering a more individualized patient care approach. Tools such as the HM3 risk score are introduced for predicting survival based on pre-implant factors, along with advanced imaging techniques for improved complication prediction. Additionally, the review highlights potential new technologies and therapies in LVAD management, such as hemodynamic ramp tests for optimal speed adjustment and advanced remote monitoring systems. The goal is to automate LVAD speed adjustments based on real-time hemodynamic measurements, indicating a shift towards more effective, patient-centered therapy. The review concludes optimistically that ongoing research and potential future innovations hold the promise of revolutionizing heart failure management, paving the way for more effective and personalized treatment modalities.

"Durable left ventricular assist devices as a bridge to transplantation in The Old and The New World".

Heart transplantation remains the gold standard treatment for end-stage heart failure patients without contraindications. However, limited donor availability and long wait times have created a need for left ventricular assist devices (LVAD) to be used as a bridge to transplantation in appropriately selected patients. Improvements in LVAD technology have resulted in improved short- and long-term outcomes, further supporting the use of these devices for a bridge-to-transplant (BTT) indication. LVAD utilization as BTT exhibits notable disparities worldwide, mainly due to variations in organ availability, allocation policies, and financial constraints. Although Europe has experienced a consistent increase in the use of LVAD for this purpose, the United Network for Organ Sharing 2018 policy amendment resulted in a significant reduction in the number of LVADs used for BTT in the US. To overcome this issue, modifications in the US allocation policy to consider factors such as days on device support, age, and type of complications may be necessary to potentially increase implantation rates.The authors provide an overview comparing the current state of heart transplantation in the US and Europe, with a particular focus on how distinct allocation policies and organ availability impact medical practices. Additionally, the review will examine critical aspects ranging from patient selection and pre-implantation optimization to post-transplant outcomes.

Hemodynamic Optimization by Invasive Ramp Test in Patients Supported With HeartMate 3 Left Ventricular Assist Device.

In patients supported by the HeartMate 3 left ventricular assist device (HM3 LVAD), pump speed adjustments may improve hemodynamics. We investigated the hemodynamic implications of speed adjustments in HM3 recipients undergoing hemodynamic ramp tests. Clinically stable HM3 recipients who underwent routine invasive hemodynamic ramp tests between 2015 and 2022 at our center were included. Filling pressure optimization, defined as central venous pressure (CVP) <12 mm Hg and pulmonary capillary wedge pressure (PCWP) <18 mm Hg, was assessed at baseline and final pump speeds. Patients with optimized pressures were compared to nonoptimized patients. Overall 60 HM3 recipients with a median age of 62 years (56, 71) and time from LVAD implantation of 187 days (124, 476) were included. Optimized filling pressures were found in 35 patients (58%) at baseline speed. Speed was adjusted in 84% of the nonoptimized patients. Consequently, 39 patients (65%) had optimized pressures at final speed. There were no significant differences in hemodynamic findings between baseline and final speeds (p > 0.05 for all). Six and 12 month readmission-free rates were higher in optimized compared with nonoptimized patients (p = 0.03 for both), predominantly due to lower cardiac readmission-free rates (p = 0.052). In stable outpatients supported with HM3 who underwent routine ramp tests, optimized hemodynamics were achieved in only 2 of 3 of the patients. Patients with optimized pressures had lower all-cause readmission rates, primarily driven by fewer cardiac-related hospitalizations.

Clinical Utility of the Molecular Microscope Diagnostic System in a Real-World Transplant Cohort: Moving Towards a New Paradigm.

Objectives: To evaluate the clinical implications of adjunctive molecular gene expression analysis (MMDx ) of biopsy specimens in heart transplant (HT ) recipients with suspected rejection. Introduction: Histopathological evaluation remains the standard method for rejection diagnosis in HT. However, the wide interobserver variability combined with a relatively common incidence of "biopsy-negative" rejection has raised concerns about the likelihood of false-negative results. MMDx, which uses gene expression to detect early signs of rejection, is a promising test to further refine the assessment of HT rejection. Methods: Single-center prospective study of 418 consecutive for-cause endomyocardial biopsies performed between November 2022 and May 2024. Each biopsy was graded based on histology and assessed for rejection patterns using MMDx. MMDx results were deemed positive if borderline or definitive rejection was present. The impact of MMDx results on clinical management was evaluated. Primary outcomes were 1-year survival and graft dysfunction following MMDx-guided clinical management. Secondary outcomes included changes in donor-specific antibodies, MMDx gene transcripts, and donor-derived cell-free DNA (dd-cfDNA) levels. Results: We analyzed 418 molecular samples from 237 unique patients. Histology identified rejection in 32 cases (7.7%), while MMDx identified rejection in 95 cases (22.7%). Notably, in 79 of the 95 cases where MMDx identified rejection, histology results were negative, with the majority of these cases being antibody-mediated rejection (62.1%). Samples with rejection on MMDx were more likely to show a combined elevation of dd-cfDNA and peripheral blood gene expression profiling than those with borderline or negative MMDx results (36.7% vs 28.0% vs 10.3%; p<0.001). MMDx results led to the implementation of specific antirejection protocols or changes in immunosuppression in 20.4% of cases, and in 73.4% of cases where histology was negative and MMDx showed rejection. 1-year survival was better in the positive MMDx group where clinical management was guided by MMDx results (87.0% vs 78.6%; log rank p=0.0017). Conclusions: In our cohort, MMDx results more frequently indicated rejection than histology, often leading to the initiation of antirejection treatment. Intervention guided by positive MMDx results was associated with improved outcomes.

Pumping for Two: Pregnancy in Patients Supported With a Left Ventricular Assist Device.

This review discusses the challenges and outcomes associated with pregnancy during left ventricular assist device (LVAD) support. Women account for a third of the heart failure population in the United States. Left ventricular assist devices have emerged as a safe and effective treatment option for patients with advanced heart failure. Pregnancy during LVAD support can occur, and it presents significant risks to both mother and fetus, including hemodynamic stress, thrombotic events, medication-associated teratogenicity, and uterine impingement. This literature review identified 10 cases of confirmed pregnancy during LVAD support, of which eight resulted in successful births. Maternal and fetal mortality occurred in one case, and there was a spontaneous abortion in one case. The review highlights the importance of a multidisciplinary approach, promotion of shared decision-making, thoughtful anticoagulation, adjustment of LVAD speed, and medication optimization to maintain hemodynamic support during pregnancy. Hemodynamic changes during pregnancy include increased cardiac output, heart rate, and plasma volume, as well as decreased systemic vascular resistance, which can impact LVAD support. Despite reduced pulsatility in LVAD-supported patients, ovulation and reproductive capacity might be preserved, and viable pregnancies may be achieved with appropriate management. The review provides insights into the risks and considerations for a viable pregnancy during LVAD support, including the need for ongoing research to inform joined decision-making.

Sex differences in patients undergoing heart transplantation and LVAD therapy.

INTRODUCTION: Left ventricular assist device (LVAD) and heart transplantation (HT) are the two life-sustaining therapies that have revolutionized the management of end-stage heart failure (HF). Yet, significant sex differences exist with respect to their use and effects. AREAS COVERED: This review summarizes sex differences in the utilization, outcomes, and complications of LVAD and HT. Particular emphasis is placed on leading clinical trials in the field, historical and recent large registries-based analyses, as well as contemporary technological and policy changes affecting these differences. EXPERT OPINION: Women with advanced HF remain under-treated with guideline-directed medical therapy and are less likely to be referred for consideration for LVAD and HT. This remains true despite newer LVAD technology and the new heart transplant allocation system. Community outreach, education, as well as increased representation of women in clinical research may reduce inequities.