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Heart failure with preserved ejection fraction (HFpEF), characterized by cardiac diastolic dysfunction, leads to premature mortality with limited effective treatments. A recent study in HFpEF patients suggested neuropilin 1 (NRP1), an endothelial cell (EC) originated prognostic marker, might contribute to the pathogenesis of HFpEF. However, the functional role of NRP1 in the pathogenesis of HFpEF remains unclear. Purpose: To determine the functional role of NRP1 in the pathogenesis of HFpEF. Hypothesis: NRP-1 contributes to the pathogenesis of HFpEF, potentially mediated through chronic inflammation. Methods: HFpEF was induced by hypertensive and metabolic stresses in control (n=14) and tamoxifen-induced, endothelial cell-specific NRP1 knockout (NRP1 iEC-KO ) mice (n=13). We assessed cardiac diastolic function via echocardiography and pressure-volume loop through invasive catheters. To determine the inflammation level, we tested leukocyte adhesion, inflammatory marker vascular cell adhesion molecule 1 (VCAM-1), and intercellular adhesion molecule 1 (ICAM-1) mRNA level in control and NRP1 shRNA knockdown (NRP1 KD) human umbilical vein endothelial cells (HUVECs) with a stimulation of TNF-α. Student t-test (two tailed) was used and the criterion level of significance was set at p<0.05. Results: We found a significantly improved diastolic function in NRP1 iEC-KO mice, evidenced by a significantly reduced end diastolic pressure in NRP1 iEC-KO mice (8±2mmHg; n=7) compared to the controls (17±2mmHg; n=9; p=0.01) after HFpEF induction. E/A ratio was also significantly lower in NRP1 iEC-KO mice (2.0±0.2; n=10) compared to controls (2.7±0.3; n=12; p=0.04). Moreover, the isovolumic relaxation time was also significantly reduced in NRP1 iEC-KO mice (18±0.8ms; n=13) compared to controls (20±0.8ms; n=14; p=0.03). In addition, In HUVECs, NRP1 KD significantly reduced inflammatory marker VCAM-1 mRNA expression (95±16; n=5) compared to controls (293±36; n=5; p<0.01) upon TNF-α treatment. Similarly, NRP1 KD significantly reduced ICAM-1 mRNA expression (44±14; n=5) compared to controls (83±9; n=5; p=0.03) upon TNF-α treatment. Furthermore, leukocyte adhesion was significantly lower in the NRP1 KD group (57.0 ±8.6 cells/field) compared to the control group (90.8 ±9.1 cells/field; p=0.04). Conclusion: Endothelial NRP1 contributes to cardiac diastolic dysfunction and the pathogenesis of HFpEF, potentially mediated through the activation of chronic low-grade inflammation.

Background: Dilated Cardiomyopathy (DCM) is a major cause of heart failure (HF) and carries a high mortality rate. Drug treatment response for DCM-related HF patients is highly variable, with some patients having no response. A pharmacogenomic approach, genome-wide association study (GWAS) followed by biologically functional validation, can potentially identify genetic determinants of prognosis in DCM and might provide insight into novel biology of DCM pharmacotherapy. Methods: A GWAS was performed using DNA from 686 patients with recent onset DCM who were on standard HF therapy using change in left ventricular ejection fraction (LVEF) at a median of 6 months after initial diagnosis. Cultured human cardiac fibroblasts (HCFs) were used to functionally validate the GWAS findings in vitro . RNA-seq followed by pathway analysis after NAV3 knock-down (KD) using siRNA in HCFs were performed to explore potential biological mechanisms. Results: A genetic variant, rs11105445(G>A), identified from the GWAS, mapping to the neuron navigator 3 (NAV3) gene (rs11105445, p=2.37E-07; beta 2.74 ± 0.53) was associated with improvement in LVEF. Functional genomic experiments demonstrated that, both in LV tissue and in cultured fibroblasts, the minor allele A was associated with decreased transcription of NAV3 (pvalue: 0.0335 and 0.0432) suggesting that ↓NAV3 expression might be associated with improvement in LVEF. TGF-β1 can induce HCF transdifferentiation into myofibroblasts and we demonstrate that it also increases NAV3 expression. NAV3 KD which mimics the GWAS variant significantly suppressed TGF-β1 induced HCF transdifferentiation demonstrated by decreased expression of α-smooth muscle actin (ACTA2) and collagen I (COL1A1). RNA-seq after NAV3 KD followed by pathway analysis suggested that NAV3 exerted its effect by regulating ECM and cell cycle processes, especially G1/S transition. We demonstrate that NAV3 KD suppressed TGF-β1 induced G1/S arrest by regulating CDK4, CDK6 and INK4B (cyclin-dependent kinase inhibitor 2B/P15, CDK4 inhibitor). Conclusion: Decreased expression of NAV3 is associated with myocardial recovery in DCM, most likely due to its role in suppressing HCF differentiation by regulating TGF-β1 induced G1/S arrest. The role of NAV3 as a novel therapeutic target in DCM needs to be explored.

Background&Hypothesis: Nicotinamide adenine dinucleotide (NAD) is a critical coenzyme, essential for a variety of cellular processes. Pulmonary arterial hypertension (PAH) is associated with impaired metabolism and reduced NAD levels that contribute to its hyperproliferative state. CD38 is an ecto-enzyme that degrades NAD and produces several byproducts including cyclic ADPR. We hypothesized that CD38 mediates pathological reductions in NAD levels contributing to PAH vascular remodeling. Methods: To test this hypothesis, we evaluated expression levels of CD38 across PAH tissues, tested its functional role in human pulmonary artery endothelial cells (PAEC) and smooth muscle cells (PASMCs), and examined the response of a global CD38 knockout mouse ( CD38 -/- ) in an established chronic hypoxic (10% FiO2, 4 weeks) model of pulmonary hypertension. Results: CD38 expression was elevated in human PAECs derived from PAH cases and in rodent whole lung homogenates. Media from PAEC exposed to a CD38 inhibitor (78c) led to reduced PASMC proliferation. CD38 -/- mice exposed to chronic hypoxia exhibited attenuated PH compared to cage controls. Specifically, histological assessment of murine lungs revealed reduced PA medial thickness compared to control. CD38 -/- mice exhibited reduced right ventricular systolic pressure and a corresponding decrease in Fulton Index after hypoxic exposure. Consistent with these results, targeted metabolite measurements revealed that CD38 -/- mice exhibited elevated NAD levels in the lungs. Discussion: These results suggest that CD38 is a novel PAH target, and its deficiency restores NAD levels in the lungs and reduces pulmonary hypertension in mice.

Background: Patients with normal resting left ventricular ejection fraction (LVEF) without either coronary artery disease (CAD) or a hypertensive response can paradoxically develop reduced LVEF during exercise stress echocardiography (ESE). The clinical phenotype and outcomes of these patients is unknown. Hypothesis: Patients who paradoxically develop reduced LVEF during exercise may represent a sub-phenotype of heart failure with preserved LVEF (HFpEF). Aims: To describe the baseline characteristics and clinical outcomes of this unique patient population. Methods: Among all ESE performed between January 2003 and December 2022, patients without a hypertensive response to exercise and without CAD by angiogram within 90 days of ESE, who had a resting LVEF ≥50% with a ≥5% LVEF decrease during ESE were identified. All-cause mortality, HF hospitalization, and atrial fibrillation (AF) outcomes were assessed. Kaplan-Meier and Cox regression methods were used to analyze time-to-event outcomes. Results: Among 213,643 stress echocardiograms performed, 134 patients met eligibility criteria (Table 1). The mean age of the population was 66±10 years, 76% were women, and 16% had AF at baseline. Mean LVEF was 58±4% at rest and 43±4% at peak stress. Stress electrocardiogram met criteria for ischemia in 14%. The 10-year all-cause mortality risk was 12.9% (95% CI 5.5-20.3) with 10 (37%) of 27 deaths due to cancer (Figure 1, Panel A). The 10-year estimated risk of HF hospitalization was 17.6% (95% CI 9.0-26.2) (Figure 1, Panel B). Among 112 patients without AF at baseline, the 10-year risk of developing AF was 23.4% (95% CI 13.4-33.4). Conclusions: Patients with exercise-induced reduced LVEF in the absence of obstructive CAD have a high incidence of HF hospitalizations and AF. Given the preponderance of women, risk for AF, HF hospitalizations, and cancer-related deaths, the possibility that this condition is an early sub-phenotype of HFpEF should be investigated.

Background: Delivering cardiac rehabilitation (CR) by telehealth may increase participation and promote equitable access to CR. Our objective was to tailor a patient-centered telehealth CR program to diverse populations. Methods: We recruited participants with varying CR experience (e.g. attended >1 session, did not attend CR, and caregivers) between January and September 2023 from four US academic medical centers. Participants engaged in human-centered design sessions on CR perspectives and a proposed telehealth CR program. Sessions were qualitatively analyzed using rapid template analysis with pre-selected behavioral science constructs and other emergent codes. Based on participant feedback, we iteratively revised the telehealth CR program and created an implementation toolkit. Results: Among 21 participants (76% ≥65 years, 50% female, 60% non-Hispanic White; 90% attended >1 session, 10% caregiver of a CR participant, 5% prefer not to answer), CR was overall regarded as valuable. Benefits included accountability, confidence, and feeling better. Social support was appreciated from family, friends, program co-participants, and CR staff. Participants emphasized the importance of early goal setting, accountability, and program individualization. Participants thought that using technology for telehealth CR could be helpful for accountability, facilitating relationships, and convenience. However, some participants had concerns about safety, especially at the start of their telehealth program, and desired checks such as a monitoring device or observation of exercise over video. Through human-centered design, safety protocols and technology training were developed, which participants thought addressed their concerns about participating in telehealth CR. The implementation toolkit informed by human-centered design included a participant journey, safety plan, home exercise plan for use during and after CR, and scripts for technology training and telehealth visits. Selected quotes are presented in Figure 1. Conclusions: We developed a patient-centered telehealth CR program and implementation toolkit. Future research will test the comparative effectiveness of in-person and telehealth CR on patient-centered outcomes.

Introduction: Heart failure with preserved ejection fraction (HFpEF) is an increasingly prevalent form of heart failure (HF) in the US today. Our prior work revealed low albumin at first hospitalization for HF exacerbation with underlying HFpEF to be an independent predictor of all-cause mortality in a small cohort of patients. We now sought to confirm our earlier findings across a larger and more diverse patient population. Methods: Seven thousand, eight hundred and forty patients had a first admission to Mayo Clinic for HF exacerbation with an echo-confirmed left ventricular ejection fraction>50% between 2010 and 2020. Patient baseline demographics, co-morbidities, admission laboratory values, echocardiographic parameters, discharge medications, and outcomes were obtained from chart abstraction. To validate our previous model, patients were grouped based on the number of risk factors as previously defined: age>80 years, serum albumin level<3.2 g/dl, medial E/e'≥20, N-terminal pro-brain natriuretic peptide (NT-proBNP) >5,000 pg/mL, and the presence of hypertension (HTN). The association with 1 year mortality was studied using Cox regression. Kaplan Meier curves were generated based on the number of factors present per patient. Results: Eleven significant univariate predictors of all-cause mortality were identified from the data (Fig. 1A), with hazard ratios (HR) ranging from 1.22-2.04 (p<0.001 for all). Notably, four previously identified prognosticators (age, albumin, medial E/e’, , HTN) were noted as significant independent predictors of all-cause mortality in HFpEF (HR 1.67, 2.14, 1.18, and 1.15, respectively, p<0.004 for all ; Fig. 1B). Multivariate regression modeling identified low albumin on presentation as being a significant adverse prognosticator (HR=2.14; p-value<0.001). Conclusion: Our analysis of 7840 HFpEF patients confirms our prior findings, suggesting that this model is a strong predictive tool for assessing the prognosis of HFpEF. Taken together, these five variables are easily available in the in-patient setting and can be incorporated into a model predictive of 1-year all-cause mortality.

Background: Major adverse cardiovascular events (MACE), including myocardial infarction, acute coronary syndrome, ischemic heart disease requiring revascularization, stroke, and heart failure, have been documented as significant contributors to mortality in cancer survivors. Coronary artery calcium (CAC) can predict MACE in non-cancer populations, while calcium in the aorta (CA) has not been evaluated as a prognostic marker. Every patient diagnosed with cancer undergoes a standard-of-care Positron Emission Tomography-Computed Tomography (PET-CT) or a chest CT before the initiation of chemotherapy. Hypothesis: To determine whether the CAC or CA of patients with Hodgkin's or non-Hodgkin's lymphoma, derived from standard-of-care PET-CT/chest CT, can predict the incidence of MACE. Methods: Patients treated with anthracycline-based chemotherapy, diagnosed and followed from January 1, 2013, through June 30, 2023, were included. Patients who did not undergo a PET-CT or CT, and/or developed MACE before treatment initiation were excluded. Univariate and multivariate adjusted Cox regression models were employed to assess whether the presence of CAC, CA, or CAC-CA was associated with the development of MACE. Calcium was retrospectively quantified using TeraRecon software (Durham NC) and categorized as: 0, 1-99, and >100. Outcome analyses was estimated using the Kaplan-Meier method. Results: 326 patients were included, mean age of 55 years (range: 52-60), predominantly male 201 (61%) and white 314 (96%), CAC was found in 89 patients and CA in 140. In the univariate regression model, a statistically significant association was found with values >100 for CA, CAC and CAC-CA with the risk of MACE. (Fig 1a/b/c). CAC equal to 0 demonstrated a significant protective effect against MACE. (Fig 1a). In the multivariable analysis, these associations persisted even after adjusting for comorbidities. (Table 1). Conclusion: CAC, CA and CAC/CA >100 in the standard-of-care CT/PET CT are predictors of MACE in lymphoma patients undergoing anthracycline treatment, a CAC equal to 0 has protective effect, these relationships remained statistically significant after adjusting for comorbidities.

Background: Although exercise stress testing (EST) has shown to unmask latent electrical substrates in PKP2 -mediated arrhythmogenic cardiomyopathy (ACM), the prognostic role of EST-induced ventricular arrhythmia (VA) patterns in PKP2-ACM patients is unclear. Objective: To examine the exercise-induced VA patterns observed during EST in PKP2-ACM patients and explore their correlation with major VA outcomes. Methods: We retrospectively analyzed 621 patients with either genotype-positive ACM or genotype-positive dilated cardiomyopathy evaluated between 01/2015 and 04/2024 to identify those with a disease-causative variant in PKP2 (N = 108). After exclusion of 38 PKP2-ACM patients without EST data, demographic and electrocardiographic data was extracted from the electronic medical record. The arrhythmic burden [premature ventricular contractions (PVCs), PVCs in bigeminy, PVC couplets, non-sustained VT (NSVT), sustained VT, ventricular fibrillation (VF), and PVCs/minute] during each EST phase (baseline, peak, active and passive recovery) were reviewed and correlated with major VA outcomes [sudden cardiac arrest (SCA), sustained VT, and appropriate implantable cardioverter-defibrillator (ICD) shocks]. Results: A total of 186 exercise tests from 70/108 (65%) PKP2-ACM patients (mean age 36 ± 20 years, 40 % male) were analyzed. The presence and burden of PVCs occurring singly, bigeminy, couplets. and NSVT were more prevalent during the recovery phase, specifically the passive recovery phase ( Table ). PKP2-ACM patients with structural disease (64%) were more likely to have an increased VA burden during recovery than those without structural disease [28/45 (62%) vs 4/25 (16%); p<0.001]. Interestingly, the presence of an increased arrhythmic burden (worsening PVCs/min or complex PVCs) during the recovery was associated with major VA over a median follow-up of 47 months (HR 8.576 [1.015-72.449]; p= 0.019). Conclusion: Increased arrhythmic burden during the recovery phase (late > early) is associated with an increased risk of major VAs in PKP2-ACM. Further studies are needed to understand if this observation extends to other ACM genotypes and whether EST-induced VA patterns can be used to assess therapeutic efficacy in PKP2-ACM.

Background: Heart failure (HF) is associated with systemic inflammation and hypercatabolic syndrome, impacting body metabolism. The advanced lung cancer inflammation index (ALI) is a novel inflammatory and nutritional biomarker. Purpose: We aimed to investigate the prognostic role of ALI in patients with HF. Methods: We comprehensively searched PubMed, WOS, SCOPUS, EMBASE, and CENTRAL through March 2024. We conducted a pair-wise and prognostic systematic review and meta-analysis with a reconstructed time-to-event data meta-analysis. All analyses were performed using R V. 4.3.1. This meta-analysis was registered at PROSPERO (CRD42024535227). Results: We included four studies with 2,247 patients. In the pair-wise meta-analysis, ALI ≤ 25 was significantly associated with an increased incidence of all-cause mortality compared with ALI > 25 (risk ratio [RR] 1.73, 95% confidence interval [CI] 1.36-2.21, P< 0.01). On the adjusted prognostic meta-analysis, higher ALI (>25) was significantly associated with a reduction in the incidence of all-cause mortality (hazards ratio [HR] 0.45, 95% CI 0.35-0.58, P< 0.01). The reconstructed Kaplan Meier showed that ALI > 25 was significantly associated with a 56% reduction in the incidence of all-cause mortality compared with ALI ≤ 25 (HR 0.44, 95% CI 0.38-0.50, P< 0.000001). Conclusion: Among patients with HF, a low ALI was associated with a higher incidence of all-cause mortality rate than those with a high ALI. These findings suggest that ALI can be used for prognostic stratification and aid clinical decision-making in HF management.