Regulation of circulating progenitor cells in left ventricular dysfunction

Feasibility of frailty screening among patients with advanced heart failure

BACKGROUND

Frailty is common among patients with advanced heart failure (HF), and screening for frailty to guide care is recommended. Although multiple tools are available to screen for frailty, the feasibility of routinely incorporating frailty screening into daily clinical practice among hospitalised advanced HF patients has not been rigorously tested.

METHODS

This was a prospective, single-centre, quality improvement study. Two brief frailty screening tools were incorporated into palliative care consultations for all patients ≥50 years from August 2021 to October 2022. In the first phase, the Clinical Frailty Scale (CFS) was implemented, followed by the Study of Osteoporotic Fracture (SOF) tool or a modified SOF (mSOF) version in the second phase. The primary outcome was feasibility (%) of performing frailty screenings for this high-risk population.

RESULTS

A total of 212 patients (mean age 69±10 years, 69% male, 79% white, 30% with ischaemic HF) were referred for palliative care consultation during the study period. Overall, frailty screens were completed in 86% (n=183) of patients. CFS and mSOF reached >80% of adoption, while SOF adoption was 54%. Altogether, 52% of the population screened frail by use of CFS and 52% also by mSOF. All clinicians (n=6) participating in the study reported that frailty screening tools were useful and acceptable, and 83% reported plans for continued utilisation in future clinical practice.

CONCLUSIONS

Frailty screening with CFS or mSOF tools was feasible in hospitalised patients with advanced HF. Tools that require physical assessment were more challenging to implement. These data support the feasibility of incorporating questionnaire-based frailty screening in a busy hospital setting.

Artificial Intelligence-Derived Electrocardiogram Assessment of Cardiac Age and Molecular Markers of Senescence in Heart Failure

OBJECTIVE

To ascertain whether heart failure (HF) itself is a senescent phenomenon independent of age, and how this is reflected at a molecular level in the circulating progenitor cell niche, and at a substrate level using a novel electrocardiogram (ECG)-based artificial intelligence platform.

PATIENTS AND METHODS

Between October 14, 2016, and October 29, 2020, CD34⁺ progenitor cells were analyzed by flow cytometry and isolated by magnetic-activated cell sorting from patients of similar age with New York Heart Association functional classes IV (n = 17) and I-II (n = 10) heart failure with reduced ejection fraction and healthy controls (n = 10). CD34⁺ cellular senescence was quantitated by human telomerase reverse transcriptase expression and telomerase expression by quantitative polymerase chain reaction, and senescence-associated secretory phenotype (SASP) protein expression assayed in plasma. An ECG-based artificial intelligence (AI) algorithm was used to determine cardiac age and difference from chronological age (AI ECG age gap).

RESULTS

CD34⁺ counts and telomerase expression were significantly reduced and AI ECG age gap and SASP expression increased in all HF groups compared with healthy controls. Expression of SASP protein was closely associated with telomerase activity and severity of HF phenotype and inflammation. Telomerase activity was more closely associated with CD34⁺ cell counts and AI ECG age gap.

CONCLUSION

We conclude from this pilot study that HF may promote a senescent phenotype independent of chronological age. We show for the first time that the AI ECG in HF shows a phenotype of cardiac aging beyond chronological age, and appears to be associated with cellular and molecular evidence of senescence.

Differential phenotype and behavior in culture of CD34 positive cells from peripheral blood and adipose tissue

The localization and quantification of endothelial progenitor cells (EPCs) are controversial. Circulating CD34 + cells in blood have been identified as EPCs and as biomarkers of cardiovascular disease. We discuss in this paper the current data describing differential phenotype and behavior in vitro of CD34 positive cells from the circulation and adipose tissue (AT). We also describe in brief our own findings from CD34 + cells isolated from leukopheresis cones derived from healthy platelet donors and from patients undergoing bariatric surgery. We conclude that CD34 + cells in blood and in AT are different in antigenic profile and behavior in culture. The findings described assert that CD34 + cells detected in blood previously identified as biomarkers of cardiovascular disease are predominantly HPCs rather than EPCs, and that true CD34 + EPCs can be readily identified and extracted from AT, supportive of the current evidence which suggests EPCs are resident in the tissue vasculature.

Isolation and Culture of Primary Endothelial Cells from Canine Arteries and Veins

Cardiovascular disease is studied in both human and veterinary medicine. Endothelial cells have been used extensively as an in vitro model to study vasculogenesis, (tumor) angiogenesis, and atherosclerosis. The current standard for in vitro research on human endothelial cells (ECs) is the use of Human Umbilical Vein Endothelial Cells (HUVECs) and Human Umbilical Artery Endothelial Cells (HUAECs). For canine endothelial research, only one cell line (CnAOEC) is available, which is derived from canine aortic endothelium. Although currently not completely understood, there is a difference between ECs originating from either arteries or veins. For a more direct approach to in vitro functionality studies on ECs, we describe a new method for isolating Canine Primary Endothelial Cells (CaPECs) from a variety of vessels. This technique reduces the chance of contamination with fast-growing cells such as fibroblasts and smooth muscle cells, a problem that is common in standard isolation methods such as flushing the vessel with enzymatic solutions or mincing the vessel prior to digestion of the tissue containing all cells. The technique we describe was optimized for the canine model, but can easily be utilized in other species such as human.