Citations

Abstract Background Renal dysfunction is a major determinant of outcomes after heart transplantation (HT). While baseline renal impairment and post-HT dialysis are known predictors of mortality, the prognostic impact of sustained pre-HT renal decline in patients bridged with durable left ventricular assist devices (LVADs) remains unclear. Methods We conducted a retrospective, multicenter cohort study using the United Network for Organ Sharing (UNOS) registry to identify adult patients who underwent HT following durable LVAD support between 2009 and 2024. Sustained renal decline was defined as a ≥40% reduction in estimated glomerular filtration rate (eGFR) from listing to HT. Multivariable logistic regression identified predictors of renal decline and post-HT dialysis,while Cox proportional hazards models assessed the impact on post-HT mortality. Results Among 10,454 eligible patients, 624 (6.0%) experienced sustained renal decline during LVAD bridging. Compared with patients without renal decline, affected patients had longer waitlist durations (median 297 vs. 197 days; p<0.001), lower eGFR at HT (42.0 vs. 70.6 mL/min/1.73 m²; p<0.001), and higher rates of post-HT dialysis (23.7% vs. 12.8%; p<0.001). Independent predictors of sustained renal decline included longer waitlist time, perioperative blood transfusions, while the use of HeartMate 3 LVAD was protective. Sustained renal decline was independently associated with increased risk of post-HT dialysis (adjusted odds ratio [aOR] 2.64) and all-cause mortality (adjusted hazard ratio [aHR] 1.16),with post-HT dialysis strongly predicting mortality (aHR 3.48). Conclusions Sustained renal deterioration while awaiting HT is a significant predictor of post-HT dialysis and mortality in LVAD-bridged patients. Incorporating renal trajectory into risk stratification may enhance candidate selection and promote perioperative renal protection strategies.

Abstract Heart failure (HF) is a major cause of hospitalization and mortality worldwide. Ventricular assist devices (VADs) represent an alternative to cardiac transplantation for advanced HF. The main FDA-approved VAD (HeartMate III, Abbott), while effective, requires major cardiac surgery to insert the inflow cannula into the cardiac apex, and is associated with numerous co-morbidities and re-hospitalizations related to continuous flow and an external drive line and power supply. Mi-VAD, Inc. aspires to improve outcomes and quality of life with a miniature, minimally invasive, pulsatile, transcutaneously-powered VAD that is implanted above the aortic valve and/or the pulmonary valve and offering a wide range of hemodynamic support suitable for both advanced-stage and less advanced HF. Through its unique placement, there is the potential for right ventricular and biventricular cardiac assist for patients with restrictive cardiomyopathy and HFpEF for whom current VAD therapy is ineffective. Mi-VAD, Inc. has achieved proof of concept with its prototype, providing pulsatile ECG gated cardiac assist up to 10L/minute. Following initial bench top performance testing and in vivo efficacy and safety studies future work will focus on the development of wireless charging capability and conducting GLP builds for verification, regulatory clearance and commercialization. Additional technical development will focus on AI-driven hemodynamic optimization using multimodal physiologic sensing towards patient-specific digital twin of the Mi-VAD platform.

Abstract Accurate assessment of left-ventricular ejection fraction (EF) is a critical metric in diagnosing and managing heart failure; however, methods of assessment remain resource intensive, not widely available in low-acuity or remote settings and are intermittent in nature. This study explores the potential of a novel framework, cardiac electromechanical fingerprinting (cEMF) using synchronized electrocardiography (ECG) and seismocardiography (SCG) collected from a wearable sensing patch as a low-cost, non-invasive, continuous estimate of EF that can be used for rapid point of care screening. A machine learning pipeline was developed to process raw ECG and SCG data to derive EF. Signals were cleaned using band-pass filtering, NeuroKit2-based ECG cleaning and fiducial detection of critical electromechanical events. We extracted an ECG-SCG feature space consisting of heart-rate variability metrics, ECG morphological characterization, SCG timing intervals, spectral and entropy-based features. The top thirty most important features for EF were used to train and evaluate several regressor models. The best performing model was the Gaussian Process Regressor with an MAE of 5.43. Our findings demonstrate the promise of producing clinically relevant cardiac function measures, such as EF, from wearable electromechanical signals. Future work using larger datasets and complementary physiological signals such as phonocardiogram (PCG) may significantly strengthen EF% estimation and other cardiac functions for clinical applicability.

Abstract Rationale Sotatercept is a novel activin signaling inhibitor approved for the treatment of pulmonary arterial hypertension (PAH). Sotatercept has been studied in randomized clinical trials, but little is known regarding the real-world use of sotatercept. We sought to describe the safety, tolerability and efficacy of sotatercept in our clinical practice. Methods We performed a combined prospective and retrospective cohort study of all patients treated with sotatercept at Mayo Clinic Rochester since its approval in March 2024. Patients enrolled in a separate clinical trial of sotatercept were excluded from this analysis as their data will be reported separately. Clinical data was abstracted from the electronic health record. Follow-up data was collected at 6 ± 3 months after initiation of sotatercept. Data is summarized as n (%) and mean ± SD. We used paired t-tests to compare baseline and follow-up characteristics within individuals. Results Fifty-eight PAH patients treated with sotatercept were included. Patients were 48.4 ± 37.6 years old at treatment initiation and were predominantly female with a mean duration of PAH of 6.7 years and a range of PAH etiologies including portopulmonary hypertension, congenital heart disease, and pulmonary veno-occlusive disease (Table 1). Twenty-one (36%) of patients had mixed etiologies of PH. Six months after initiation of sotatercept, patients had a significant improvement in NTproBNP (1922 ± 4464 to 363 ± 596 pg/ml, p = 0.04), 6 minute walk distance (378.8 ±144.6 to 395.7±129.5 meters, p = 0.02) and right ventricular systolic pressure (74.6 ± 20.5 to 60.6 ± 20.3 mm Hg, p < 0.001). No patients permanently discontinued due to abnormal laboratory values. Mean highest hemoglobin achieved over the initial 6 months of treatment was 15.5 ± 2.1 g/dL and mean lowest platelet count was 181 ± 74K. Seven patients discontinued sotatercept at a range of 170-275 days after starting. Four patients discontinued due to possible treatment-related adverse effects: 1 each of gastrointestinal hemorrhage, retinal hemorrhage, hypoxia/intrapulmonary vasodilatation and spontaneous bilateral subdural hematomas. Three patients discontinued due to other reasons: newly diagnosed metastatic cancer leading to transition to hospice and two due to lack of improvement. Conclusions In this real-world registry of sotatercept in PAH, sotatercept was well-tolerated among patients with PAH and associated with improvements in exercise capacity, echocardiographic parameters, and NTproBNP. Overall discontinuation due to possible treatment-related adverse effects was low and reasons for discontinuation included bleeding and hypoxia attributed to intrapulmonary vasodilatation. This abstract is funded by: None

Background Medication nonadherence has been associated with poor outcomes in transplant recipients yet identifying these behaviors pre-transplant remains challenging. The simplified medication adherence questionnaire (SMAQ) is a brief, reliable instrument to assess medication adherence. The aim of this study was to perform SMAQ testing on thoracic organ candidates and examine correlations between these scores and individual patient factors predicting medication nonadherence. Methods Consenting waitlisted lung, heart, and heart-lung transplant candidates from six thoracic transplant centers were mailed a survey that included demographic information and the Simplified Medication Adherence Questionnaire (SMAQ). Univariate logistic regression analysis was performed to assess association between pre-transplant medication adherence and demographic characteristics, psychosocial factors, and mortality. Results Among 298 participants, 60.7% were medication nonadherent. Nonadherence was associated with some college education (OR: 1.73; CI: 1.06, 2.81), lower positive affect (OR: 0.95; CI: 0.92, 0.99), and higher uncertainty (OR: 1.02; CI: 1.01, 1.04). Higher positivity ratio predicted adherence. Conclusion Identifiable patient-specific characteristics associated with medication nonadherence can be screened for during thoracic transplant evaluation. Interventions aimed at improving these factors during the pre-transplant period may improve clinical post-transplant outcomes, however, larger studies are needed to validate these findings.

Background. Acute cellular rejection (ACR) remains a major cause of morbidity after heart transplantation despite advances in immunosuppression. Whole genome transcriptomic profiling offers a systems-based, unbiased approach to elucidate the molecular mechanisms underlying ACR. However, noninvasive, longitudinal biomarker assessments capable of capturing the temporal dynamics of rejection biology remain scarce. Methods. RNA sequencing of peripheral blood from heart transplant recipients before, during, and after ACR was compared with nonrejection controls. Pathway analysis was conducted using differentially expressed genes (DEGs), and a machine learning approach was applied to assess gene-based prediction of ACR. Results. A total of 235 rejection-specific significant DEGs and 863 postrejection DEGs (false discovery rate < 0.05) were identified. During ACR, DEGs were enriched for T-cell activation/differentiation, apoptosis, and B-cell receptor signaling pathways. By combining the 2 sets of DEGs, a panel of 71 common genes was identified that reflected the significant, longitudinal transcriptomic dynamics of ACR. In an elastic net machine learning–based classifier, DYNLL1 and SERF2 were identified as ACR predictive genes, and achieved a cross-validated area under the receiver operating characteristic curve of 0.63. Conclusions. Peripheral blood transcriptomics identify dynamic temporal responses in ACR including T- and B-cell pathways with potential ACR predictive genes that warrant further investigation.

Abstract The expanding use of continuous‐flow left ventricular assist devices (CF‐LVADs) for end‐stage heart failure warrants familiarity with the physiologic interaction of the device with the native circulation. Contemporary devices utilize predominantly centrifugal flow and, to a lesser extent, axial flow rotors that vary with respect to their intrinsic flow characteristics. Flow can be manipulated with adjustments to preload and afterload as in the native heart, and ascertainment of the predicted effects is provided by differential pressure‐flow ( H ‐ Q ) curves or loops. Valvular heart disease, especially aortic regurgitation, may significantly affect adequacy of mechanical support. In contrast, atrioventricular and ventriculoventricular timing is of less certain significance. Although beneficial effects of device therapy are typically seen due to enhanced distal perfusion, unloading of the left ventricle and atrium, and amelioration of secondary pulmonary hypertension, negative effects of CF‐LVAD therapy on right ventricular filling and function, through right‐sided loading and septal interaction, can make optimization challenging. Additionally, a lack of pulsatile energy provided by CF‐LVAD therapy has physiologic consequences for end‐organ function and may be responsible for a series of adverse effects. Rheological effects of intravascular pumps, especially shear stress exposure, result in platelet activation and hemolysis, which may result in both thrombotic and hemorrhagic consequences. Development of novel solutions for untoward device‐circulatory interactions will facilitate hemodynamic support while mitigating adverse events. © 2021 American Physiological Society. Compr Physiol 12:1‐37, 2021.

Abstract Heart transplantation (HT) is one of the prodigious achievements in modern medicine and remains the cornerstone in the treatment of patients with advanced heart failure. Advances in surgical techniques, immunosuppression, organ preservation, infection control, and allograft surveillance have improved short‐ and long‐term outcomes thereby contributing to greater clinical success of HT. However, prolonged allograft and patient survival following HT are still largely restricted by the development of late complications, including allograft rejection, infection, cardiac allograft vasculopathy (CAV), and malignancy. The introduction of mTOR inhibitors early after HT has demonstrated multiple protective effects against CAV progression, renal dysfunction, and tumorigenesis. Therefore, several HT programs increasingly use mTOR inhibitors with partial or complete withdrawal of calcineurin inhibitor (CNI) in stable HT patients to reduce complications risk and improve long‐term outcomes. Furthermore, despite a substantial improvement in exercise capacity and health‐related quality of life after HT as compared to advanced heart failure patients, most HT recipients remain with a 30% to 50% lower peak oxygen consumption (Vo 2 ) than that of age‐matched healthy subjects. Several factors, including alterations in central hemodynamics, HT‐related complications and alterations in the musculoskeletal system, and peripheral physiological abnormalities, presumably contribute to the reduced exercise capacity following HT. Cardiac denervation and subsequent loss of sympathetic and parasympathetic regulation are responsible for various physiological alterations in the cardiovascular system, which contributes to restricted exercise tolerance. Restoration of cardiac innervation may improve exercise capacity and quality of life, but the reinnervation process is only partial even several years after HT. Multiple studies have shown that aerobic and strengthening exercise interventions improve exercise capacity by increasing maximal heart rate, chronotropic response, and peak Vo 2 after HT. Novel exercise modalities, such as high‐intensity interval training (HIT), have been proven as safe and effective for further improvement in exercise capacity, including among de novo HT recipients. Further developments have recently emerged, including donor heart preservation techniques, noninvasive CAV and rejection surveillance methods, and improvements in immunosuppressive therapies, all aiming at increasing donor availability and improving late survival after HT. © 2023 American Physiological Society. Compr Physiol 13:4719‐4765, 2023.

ABSTRACT Background Addition of left heart catheterization (LHC) to exercise protocols allows for a unique focus on parameters of systolic and diastolic responses to increased activity in patients with left ventricular assist device (LVAD) support. Methods A retrospective review was conducted of all consecutive adult patients who underwent LHC with exercise for any indication from June 2017 to June 2023. For all patients, the relationship between exercise and parameters of LV systolic and diastolic response was assessed. Patients were divided into two cohorts based on the indication for testing: hemodynamic optimization (Optim, n = 5) or weaning consideration (Wean, n = 3). Results Eight patients (88% male, median age 57 years (IQR 44, 65)) were included. LVEF was 45% (IQR 45, 56) in Wean and 25% (IQR 20, 42) in Optim. LV systolic work index (LVSWI) increased more rapidly over levels of exercise in Wean vs. Optim (slope 46.3 vs. −0.625; p = 0.044) and LVSWI rose more quickly at lower levels of LV end diastolic pressure (LVEDP) in Wean vs. Optim (slope 219.5 vs. −2.008; p = 0.0026). Pulse power index was higher in Wean patients at baseline (0.046 (IQR 0.04, 0.07) vs. 0.016 (IQR 0.001, 0.04); p = 0.14) and peak exercise (0.12 (IQR 0.12, 0.12) vs. 0.06 (IQR 0.03, 0.1); p = 0.29). Conclusions Patients with favorable remodeling on LVAD support have significantly improved LV systolic and diastolic responses to exercise and a trend of higher systemic pulsatility. Improving our understanding of LV‐LVAD interactions with activity may aid in future efforts to improve exercise tolerance through speed modulation.

Abstract Opioid use disorder (OUD) affects over 40 million people worldwide, creating significant social and economic burdens. Medication for opioid use disorder (MOUD) is often considered the primary treatment approach for OUD. MOUD, including methadone, buprenorphine, and naltrexone, is effective for some, but its benefits may be limited by poor adherence to treatment recommendations. Immunopharmacotherapy offers an innovative approach by using vaccines to generate antibodies that neutralize opioids, blocking them from crossing the blood-brain barrier and reducing their psychoactive effects. To date, only 3 clinical trials for opioid vaccines have been published. While these studies demonstrated the potential of opioid vaccines for relapse prevention, there is currently no standardized protocol for evaluating their effectiveness. We have reviewed recent preclinical studies that demonstrated the efficacy of vaccines targeting opioids, including heroin, morphine, oxycodone, hydrocodone, and fentanyl. These studies showed that vaccines against opioids reduced drug reinforcement, decreased opioid-induced antinociception, and increased survival rates against lethal opioid doses. These studies also demonstrated the importance of vaccine formulation and the use of adjuvants in enhancing antibody production and specificity. Finally, we highlighted the strengths and concerns associated with the opioid vaccine treatment, including ethical considerations.