Relationship of Vascular Endothelial Growth Factor C, a Lymphangiogenesis Modulator, With Edema Formation, Congestion and Outcomes in Acute Heart Failure

Design and rationale of the eLym™ System for Decompensation of Excess Lymphatic Fluid via the Thoracic Duct in Acute Heart Failure (DELTA-HF)

AIMS

The interstitial space is the major compartment in which the excess fluid is located, forming peripheral congestion in acute decompensated heart failure (ADHF). The lymphatic system is responsible for the constant drainage of the compartment. In ADHF, the inefficiency of this system causes extravascular fluid accumulation, underscoring the crucial role of lymphatic system failure in ADHF's pathophysiology. The eLym™ System is a transcutaneous device designed to facilitate lymph drainage by creating a low-pressure zone in the thoracic duct area, theoretically allowing more efficient decompression of the lymphatic system.

METHODS AND RESULTS

The safety and feasibility of the eLym™ System for the Decongestion of Excess Lymphatic Fluid via the Thoracic Duct in Acute Decompensated Heart Failure: DELTA-HF Study is a prospective, multicentre, single-arm study designed to evaluate the safety and feasibility of the WhiteSwell eLym™ System in the treatment of fluid overload in ADHF. A maximum of 50 subjects may be enrolled and undergo the treatment. Inclusion criteria include the presence of congestion, a home diuretic dose ≥80 mg furosemide (or equivalent) and elevated natriuretic peptides. The key exclusion criteria include anatomical abnormalities and the inability to undergo systemic anticoagulation. The study endpoints include the safety (short- and long-term) and feasibility of the procedure. Several congestion indexes will be prospectively assessed. Descriptive statistics will summarize the study results. The study was registered in clinicaltrial.gov (NCT05747196).

CONCLUSIONS

The results of the DELTA-HF study will provide information about the safety and feasibility of the eLym™ System and will provide first-in-human clinical signals of its use in ADHF patients.

Lower extremity lymphatic flow is associated with diuretic response in acute heart failure

AIMS

The dysfunctional lymphatic system appears to play an important role in the development and progression of congestion in heart failure. We hypothesized that in acute heart failure (AHF), diuretic efficacy is associated with peripheral lymph flow.

METHODS AND RESULTS

We prospectively studied AHF patients who received protocolized diuretics followed by assessment of lower limb flow using indocyanine green lymphangiography (a validated method for visualization of lymphatic drainage). The lymph flow was defined as 'present' when it reached the ankle and 'significant' when it reached >10 cm within 10 min of dye injection, respectively. Based on diuretic efficacy (defined as cumulative diuresis and weight loss), patients were classified as diuretic responders vs. non-responders. Overall, 65 patients (mean age: 67 ± 15 years, median [Q1-Q3] N-terminal pro-B-type natriuretic peptide: 6901 [4478-12 723] pg/ml) were examined. There were 43 (66%) diuretic responders and 22 (34%) non-responders who did not differ in baseline clinical/laboratory characteristics. Among the responders, there were more patients with lymph flow either 'present' or 'significant' (95% vs. 73% and 88% vs. 45% vs non-responders, respectively, p < 0.01). Responders had significantly longer median distance lymph reached within 10 min (50 [24-75] vs. 10 [3-38] cm; p < 0.0005). There was a significant association between lymph flow and 6-h diuresis with β (standard error) of 0.45 (0.13) (p < 0.005). In the multivariable analyses, lymph flow distance (odds ratio 1.48, 95% confidence interval 1.08-2.03) independently predicted diuretic efficacy (p < 0.05).

CONCLUSION

For the first time, faster lower limb lymph flow was linked with better diuretic efficacy in AHF. Studies are needed to determine whether the lymphatic system can become a therapeutic target for decongestion.

Endothelial Markers in Type 2 Diabetic Patients with Acute Decompensated Heart Failure: A Pilot Study

BACKGROUND

Impaired endothelial function has been associated with vascular complications in type 2 diabetes (T2D), but its role in T2D-related heart failure (HF) remains indeterminate. The aim of this study was to assess selected markers of endothelial function in T2D patients with acute decompensated HF.

METHODS

A pilot prospective study on patients with acute decompensated HF requiring in-hospital admission was carried out. The vascular endothelial growth factor (VEGF), intercellular adhesion molecule 1 (ICAM-1), and vascular cell adhesion molecule 1 (VCAM-1) were assessed at admission and after decongestion. Subsequently, differences in these markers between T2D and non-diabetic (ND) patients were studied.

RESULTS

In total, 39 patients (21 with T2D and 18 ND patients) were enrolled. Twenty-eight patients presented with preserved ejection fraction (EF), and 11 presented with reduced EF. Looking at the VEGF levels in T2D patients, on admission, a median of 233.0 pg/mL (1.7-598 pg/mL) was found compared to 106.0 pg/mL (1.7-888 pg/mL) in ND individuals; the differences reached statistical significance (p = 0.04). There were no significant differences in VEGF levels after decongestion, and in VCAM-1 (2237 ± 1195 vs. 2699 ± 1093 ng/mL, p = 0.37) and ICAM-1 (596 ± 268 vs. 638 ± 437 ng/mL, p = 0.79) levels between T2D and ND patients upon admission and after decongestion. The value of EF (preserved or reduced) affected the VEGF levels upon admission.

CONCLUSIONS

This study identified significantly higher VEGF levels upon admission due to acute decompensated HF in T2D patients.

Disease-Specific Alteration of Cardiac Lymphatics: A Review from Animal Disease Models to Clinics

For many years, the significance of cardiac lymphatic vessels was largely overlooked in clinical practice, with little consideration given to their role in the pathophysiology or treatment of cardiac diseases. However, recent research has brought renewed attention to these vessels, progressively illuminating their function and importance within the realm of cardiovascular science. Experimental studies, particularly those utilizing animal models of cardiac disease, have demonstrated a clear relationship between cardiac lymphatic vessels and both the pathogenesis and progression of these conditions. These findings have prompted a growing interest in potential therapeutic applications that specifically target the cardiac lymphatic system. Conversely, while clinical investigations into cardiac lymphatics remain limited, recent studies have begun to explore their identification through specific surface markers, as well as the expression dynamics of lymphangiogenic factors. These studies have increasingly highlighted associations of lymphatic dysfunction with inflammation and fibrosis, both of which negatively impact cardiac function and remodeling across various pathological states. Despite these advances, comprehensive reviews of the current knowledge regarding the cardiac lymphatic vasculature, particularly within specific disease contexts, remain scarce. This review aims to address this gap by providing a detailed synthesis of existing reports, encompassing both animal model research and studies on human clinical specimens, with a special focus on the role of cardiac lymphatic vessels in different disease states.

Decongestion in acute heart failure: Is it time to change diuretic-centred paradigm?

Congestion is a common cause of clinical deterioration and the most common clinical presentation at admission in acute heart failure (HF). Therefore, finding effective and sustainable ways to alleviate congestion has become a crucial goal for treating HF patients. Congestion is a result of complex underlying pathophysiology; therefore, it is not a direct cause of the disease but its consequence. Any therapy that directly promotes sodium/water removal only, thus targeting only clinical symptoms, neither modifies the natural course of the disease nor improves prognosis. This review aims to provide a comprehensive evaluation of the current decongestive therapies and propose a new (not diuretic-centred) paradigm of long-term congestion management in HF that attempts to correct the underlying pathophysiology, thus improving congestion, preventing its development, and favourably altering the natural course of the disease rather than merely treating its symptoms.

Lower Extremity Lymphatic Flow/Drainage Assessment by Indocyanine Green Fluorescent Lymphography in Heart Failure Patients

The purpose of this study was to present a protocol for visualizing lymphatic flow in patients with heart failure (HF) by using indocyanine green fluorescence lymphography. We studied 37 subjects: 20 patients with acute heart failure (AHF) and lower limb edema, 7 patients with chronic heart failure (CHF) without lower limb edema, and 10 control subjects (no HF, no limb edema). All subjects were assessed at rest, and 11 subjects (6 control and 5 with CHF) were assessed again after a 10-minute walk. The lymph flow was visualized in all selected patients without complications. At rest, there was either no lymph flow or minimal lymph flow in all control subjects and patients with CHF, whereas the majority of patients with AHF demonstrated significant lymph flow. This study describes a new method to visualize/assess lymphatic flow in patients with HF, allowing for continuous, real-time tracking of lymphatic flow in the lower extremity.

A division-of-labor mode contributes to the cardioprotective potential of mesenchymal stem/stromal cells in heart failure post myocardial infarction

Background

Treatment of heart failure post myocardial infarction (post-MI HF) with mesenchymal stem/stromal cells (MSCs) holds great promise. Nevertheless, 2-dimensional (2D) GMP-grade MSCs from different labs and donor sources have different therapeutic efficacy and still in a low yield. Therefore, it is crucial to increase the production and find novel ways to assess the therapeutic efficacy of MSCs.

Materials and methods

hUC-MSCs were cultured in 3-dimensional (3D) expansion system for obtaining enough cells for clinical use, named as 3D MSCs. A post-MI HF mouse model was employed to conduct in vivo and in vitro experiments. Single-cell and bulk RNA-seq analyses were performed on 3D MSCs. A total of 125 combination algorithms were leveraged to screen for core ligand genes. Shinyapp and shinycell workflows were used for deploying web-server.

Result

3D GMP-grade MSCs can significantly and stably reduce the extent of post-MI HF. To understand the stable potential cardioprotective mechanism, scRNA-seq revealed the heterogeneity and division-of-labor mode of 3D MSCs at the cellular level. Specifically, scissor phenotypic analysis identified a reported wound-healing CD142+ MSCs subpopulation that is also associated with cardiac protection ability and CD142- MSCs that is in proliferative state, contributing to the cardioprotective function and self-renewal, respectively. Differential expression analysis was conducted on CD142+ MSCs and CD142- MSCs and the differentially expressed ligand-related model was achieved by employing 125 combination algorithms. The present study developed a machine learning predictive model based on 13 ligands. Further analysis using CellChat demonstrated that CD142+ MSCs have a stronger secretion capacity compared to CD142- MSCs and Flow cytometry sorting of the CD142+ MSCs and qRT-PCR validation confirmed the significant upregulation of these 13 ligand factors in CD142+ MSCs.

Conclusion

Clinical GMP-grade 3D MSCs could serve as a stable cardioprotective cell product. Using scissor analysis on scRNA-seq data, we have clarified the potential functional and proliferative subpopulation, which cooperatively contributed to self-renewal and functional maintenance for 3D MSCs, named as "division of labor" mode of MSCs. Moreover, a ligand model was robustly developed for predicting the secretory efficacy of MSCs. A user-friendly web-server and a predictive model were constructed and available (https://wangxc.shinyapps.io/3D_MSCs/).

Effect of Personalized Sodium Replacement on Fluid and Sodium Balance and Thermophysiological Strain During and After Ultraendurance Running in the Heat

PURPOSE

To investigate the effect of personalized sweat sodium replacement on drinking behavior, sodium and water balance, and thermophysiological responses during and after ultraendurance running in hot conditions.

METHODS

Nine participants (7 male, 2 female) completed two 5-hour treadmill runs (60% maximum oxygen uptake, 30°C ambient temperature), in a double-blind randomized crossover design, consuming sodium chloride (SODIUM) capsules to replace 100% of previously assessed losses or placebo (PLACEBO). Fluid was consumed ad libitum.

RESULTS

No effect of SODIUM was observed for ad libitum fluid intake or net fluid balance (P > .05). Plasma sodium concentration increased in both trials, but to a greater extent in SODIUM at 2.5 hours (mean [SD]: 4 [4] mmol·L-1 vs 1 [5] mmol·L-1; P < .05) and postexercise (4 [3] mmol·L-1 vs 1 [5] mmol·L-1; P < .05). Plasma volume change was not different between trials (P > .05) but was strongly correlated with sodium balance in SODIUM (r = .880, P < .01). No effect of sodium replacement was observed for heart rate, rectal temperature, thermal comfort, perceived exertion, or physiological strain index. During the 24 hours postexercise, ad libitum fluid intake was greater following SODIUM (2541 [711] mL vs 1998 [727] mL; P = .04), as was urinary sodium excretion (NaCl: 66 [35] mmol, Pl: 21 [12] mmol; P < .01).

CONCLUSIONS

Personalized sweat sodium replacement during ultraendurance running in hot conditions, with ad libitum fluid intake, exacerbated the rise in plasma sodium concentration compared to no sodium replacement but did not substantially influence overall body-water balance or thermophysiological strain. A large sodium deficit incurred during exercise leads to substantial renal sodium conservation postexercise.

Role of Lymphatics in Heart Failure

The lymphatic system plays a crucial, yet often overlooked, role in maintaining fluid homeostasis, and its dysregulation is a key feature of heart failure (HF). Lymphatic dysregulation in patients with HF typically results from a combination of self-perpetuating congestive mechanisms, such as increased fluid filtration, decreased lymph drainage into the central venous system, impaired lymph vessel integrity, dysfunctional lymphatic valves, and dysfunctional renal lymphatic system. These pathomechanisms collectively overwhelm the lymphatic system and hinder its ability to decongest the interstitial space with subsequent manifestation and progression of clinical congestion. Targeting the lymphatic system to counteract these congestive pathomechanisms and facilitate interstitial fluid removal represents a novel pathway to treat congestion in HF. In this study, we discuss the physiological roles of the lymphatic system in fluid homeostasis and the pathophysiological alteration of these roles in HF. We also discuss innovative technologies that aim to use the lymphatic system pathway to treat congestion in HF and provide future directions related to these approaches.

Common Variants on FGD5 Increase Hazard of Mortality or Rehospitalization in Patients With Heart Failure From the ASCEND-HF Trial

BACKGROUND

Heart failure remains a global health burden, and patients hospitalized are particularly at risk, but genetic associates for subsequent death or rehospitalization are still lacking.

METHODS

The genetic substudy of the ASCEND-HF trial (Acute Study of Clinical Effectiveness of Nesiritide in Decompensated Heart Failure) was used to perform genome-wide association study and transethnic meta-analysis. The overall trial included the patients of self-reported European ancestry (n=2173) and African ancestry (n=507). The end point was death or heart failure rehospitalization within 180 days. Cox models adjusted for 11 a priori predictors of rehospitalization and 5 genetic principal components were used to test the association between single-nucleotide polymorphisms and outcome. Summary statistics from the 2 populations were combined via meta-analysis with the significance threshold considered P<5×10-8.

RESULTS

Common variants (rs2342882 and rs35850039 in complete linkage disequilibrium) located in FGD5 were significantly associated with the primary outcome in both ancestry groups (European Americans: hazard ratio [HR], 1.38; P=2.42×10-6; African ancestry: HR, 1.51; P=4.43×10-3; HR in meta-analysis, 1.41; P=4.25×10-8). FGD5 encodes a regulator of VEGF (vascular endothelial growth factor)-mediated angiogenesis, and in silico investigation revealed several previous genome-wide association study hits in this gene, among which rs748431 was associated with our outcome (HR, 1.20; meta P<0.01). Sensitivity analysis proved FGD5 common variants survival association did not appear to operate via coronary artery disease or nesiritide treatment (P>0.05); and the signal was still significant when changing the censoring time from 180 to 30 days (HR, 1.39; P=1.59×10-5).

CONCLUSIONS

In this multiethnic genome-wide association study of ASCEND-HF, single-nucleotide polymorphisms in FGD5 were associated with increased risk of death or rehospitalization. Additional investigation is required to examine biological mechanisms and whether FGD5 could be a therapeutic target.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT00475852.