bluuebunny/crossref_metadata_2025 huggingface dataset:
Barriers to and facilitators of the uptake of digital health technology in cardiology: a systematic review
Authors: Whitelaw S , Pellegrini D , Van Spall H.G.C
Published: November 2020

Background

Digital health technology has the potential to revolutionize the quality and efficiency of healthcare delivery. However, the uptake of digital health technology has been low in clinical practice. The factors that contribute to the limited adoption of digital health technology, particularly in cardiology, are unclear.

Purpose

We identified and synthesized the barriers to and facilitators of digital health technology uptake in cardiology, with a focus on provider- and patient- level barriers and facilitators.

Methods

We searched MEDLINE, EMBASE and CINAHL databases for studies published January 2000 - December 2019 that reported barriers to and/or facilitators of digital health technology adoption in cardiology. Two reviewers screened and extracted data independently. We conducted a thematic analysis to identify major themes pertaining to digital health technology uptake by both providers and patients.

Results

The search identified 3062 unique studies, of which 23 qualitative studies met eligibility criteria. Seventeen studies included semi-structured interviews and 6 included focus groups. Five (22%) studies reported provider-level facilitators, which included technology usability, integration into clinical workflow, and improved patient outcomes. Eighteen (78%) studies reported patient-level facilitators, which included ongoing technical support, improved access to healthcare services, and improved self-management. Six (26%) studies reported provider-level barriers, which included lack of integration into clinical workflow, increased healthcare costs, and lack of validation and reliability of technology. Finally, 19 (83%) studies reported patient-level barriers which included lack of knowledge about technology, limited internet access, and physical impairments making use of technology difficult.

Conclusions

Identifying barriers to and facilitators of digital health technology could help improve its uptake in cardiology. The findings of this study can be used to inform researchers, clinicians, and stakeholders who wish to develop and implement digital health technologies that meet the needs of providers and patients.

Funding Acknowledgement

Type of funding source: None
mHealth interventions in the management of heart failure, ischaemic heart disease and hypertension: a systematic review and meta-analysis of randomised controlled trials
Authors: Indraratna P , Tardo D , Yu J , Delbaere K , Brodie M , Lovell N , Ooi S
Published: November 2020

Introduction

Cardiovascular disease (CVD) remains the leading cause of death in the world. Mobile phones have become ubiquitous in most developed societies. Smartphone applications, telemonitoring and clinician-driven short message service (SMS) allow for novel methods in managing chronic cardiovascular conditions such as ischaemic heart disease, heart failure and hypertension.

Purpose

To evaluate the impact of mobile phone-based interventions (MPIs) on mortality, hospitalisations and blood pressure and body mass index (BMI) in patients diagnosed with either acute coronary syndrome, heart failure or hypertension.

Methods

A systematic review was conducted using seven electronic databases, identifying all randomised control trials (RCTs) featuring an MPI in the management of these conditions. Meta-analysis was performed by using standard analytical techniques. The odds ratio (OR) was used as a summary statistic.

Results

Twenty-six RCTs including 6,713 patients were identified. Of these 26 studies, 13 examined text messaging intereventions, 10 studied telemonitoring interventions and three described smartphone applications with other functions. Twelve studies were included for meta-analysis. In patients with heart failure (n=1683), MPIs were associated with a significantly lower rate of all-cause hospital admissions at six months (31% vs. 36%, OR 0.77, 95% CI 0.62–0.97, p=0.03, I2 = 0). A significant difference was also demonstrated for heart-failure admissions (14.0% vs. 18.5%, OR 0.69, 95% CI 0.48 to 0.98, p=0.04, I2 = 26%). There was no difference in mortality (10.4% vs. 11.6% p=0.45). In patients with hypertension, the difference in systolic BP was 4.3mmHg less in the intervention group (95% CI: −7.8 to −0.78 mmHg, p=0.02). Four studies examined medication compliance as an endpoint in patients with ischaemic heart disease, and all four demonstrated a significant difference favouring the MPI group (see table 1). However, due to variable quantification of compliance, meta-analysis was not possible. There was no significant difference in the change in BMI from four studies after six or more months (mean difference −0.46, 95% CI: −1.44 to 0.52, P=0.36).

Conclusions

The available data suggests MPIs may have a role as valuable adjuncts in the management of chronic CVD.

Figure 1

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): National Health and Medical Research Council (NHMRC)
Air pollution and out-of-hospital cardiac arrest risk
Authors: Moderato L , Lazzeroni D , Biagi A , Spezzano T , Matrone B , Piepoli M.F , Binno S , Villani G.Q , Aschieri D
Published: November 2020

Introduction

Out-of-hospital cardiac arrest (OHCA) is a leading cause of death worldwide; it accounts for up to 50% of all cardiovascular deaths.It is well established that ambient air pollution triggers fatal and non-fatal cardiovascular events. However, the impact of air pollution on OHCA is still controversial. The objective of this study was to investigate the impact of short-term exposure to outdoor air pollutants on the incidence of OHCA in the urban area of Piacenza, Italy, one of the most polluted area in Europe.

Methods

From 01/01/2010 to 31/12/2017 day-by-day PM10 and PM2.5 levels, as well as climatic data, were extracted from Environmental Protection Agency (ARPA) local monitoring stations. OHCA were extracted from the prospective registry of Community-based automated external defibrillator Cardiac arrest “Progetto Vita”. OHCA data were included: audio recordings, event information and ECG tracings. Logistic regression analysis was used to estimate the association between the risk of OHC, expressed as odds ratios (OR), associated with the PM10 and PM2.5 levels.

Results

Mean PM10 levels were 33±29 μg/m3 and the safety threshold (50 μg/m3) recommended by both WHO and Italian legislation has been exceeded for 535 days (17.5%). Mean PM 5 levels were 33±29 μg/m3. During the follow-up period, 880 OHCA were recorded on 750 days; the remaining 2174 days without OHCA were used as control days. Mean age of OHCA patients was 76±15 years; male gender was prevalent (55% male vs 45% female; <0.001). Concentration of PM10 and PM 2.5 were significantly higher on days with the occurrence of OHCA (PM10 levels: 37.7±22 μg/m3 vs 32.7±19 μg/m3; p<0.001; PM 2.5 levels: 26±16 vs 22±15 p<0.001). Risk of OHCA was significantly increased with the progressive increase of PM10 (OR: 1.009, 95% CI 1.004–1.015; p<0.001) and PM2.5 levels (OR 1.012, 95% CI 1.007–1.017; p<0.001). Interestingly, the above mentioned results remain independent even when correct for external temperature or season (PM 2.5 levels: p=0.01 – PM 10 levels: p=0.002), Moreover, dividing PM10 values in quintiles, a 1.9 fold higher risk of cardiac arrest has been showed in the highest quintile (Highest quintile cut-off: <48μg/m3)

Conclusions

In large cohort of patients from a high pollution area, both PM10 and PM2.5 levels are associated with the risk of Out-of-hospital cardiac arrest.

PM10 and PM2.5 levels and risk of OHCA

Funding Acknowledgement

Type of funding source: None
LVAD as destination therapy in Belgium: unmet needs and political bias
Authors: Timmermans P
Published: November 2020

Objective

To determine the impact, unmet needs and the role of left ventricular assist device (LVAD) treatment as destination therapy (DT) of heart failure (HF) in Belgium. At the moment, LVAD is only approved as “bridge to transplant” since health economical analysis calculated an unacceptable high price per QALY (84.00€).

Design

Retrospective epidemiological study on HF.

Setting and parameters

Parameters in advanced HF for Belgium, the UK (both non-DT adopters), Germany and the Netherlands (DT policies) are compared. Heart transplant (HTx) rates were consulted from (inter)national transplant organisations; implantation rates were requested from the 2 manufacturers.To quantify the impact of HF in Belgium, indirect measures on hospital admission were obtained by using the International Codes of Disease. Equity between HF and oncology was assessed by analysing approval of novel treatments. Timeframe is from 2009 till 2018.

Results

The last 10 years, mean HTx rates per million inhabitants are 6.8 in Belgium, 3.8 in Germany, 2.4 in the Netherlands and 2.5 in the UK. Transplant waiting lists are progressively exceeding the number of transplants – except in Germany. Combination of HTx and LVAD use show distinct patterns in advanced HF, with a 3-fold difference between the highest user (15,1: Germany in 2017) compared to the lowest user (4,9: UK in 2016). The need for advanced HF therapies is calculated at 14.9 per million. 8 additional LVAD implants were required in Belgium in 2018 to reach this goal.

ICDcodings in Belgium show an upwards trend, indicating that the burden of HF is increasing in Belgium. Cardiovascular diseases are still the most important cause of death in Belgium according to the latest OECD report. From 2009 till 2016, 100 new cancer drugs were approved by the EMA. Only 18 of them showed a significant survival benefit as compared to standard treatment. From them, only 1 (trastuzumab) was evaluated in a health economical assessment for the Belgian health care system.

Conclusions

There is a growing discrepancy between supply and demand in advanced HF in Belgium. The additional number of LVADs and associated impact on total healthcare expenditure is calculated to be low due to a successful HTx program. LVAD as DT should therefore be considered to cover the needs for the Belgian population.

The Netherlands and the UK are adopting “opt out” default organ donation legislations in 2020, and this could decrease the demand-supply mismatch in advanced HF.

The lack of robust epidemiological data in HF could be the cause of political bias towards oncology as compared to cardiology. The ESC should therefore strive to improve registration of LVAD use to better monitor changing health care needs, promote epidemiological research and facilitate interaction with policy makers.

Figure 1

Funding Acknowledgement

Type of funding source: None
Cost Needed to Treat (CNT) and Number Needed to Treat (NNT) analysis of drugs for treatment of heart failure in India
Authors: Mullavelil K , George V , Thannikkal A , Aravindakshan R , John D , Koshy C , Venugopal K
Published: November 2020

Background

Only little attention has been paid to treatment strategies of chronic disease conditions that require long term treatment and repeated hospitalizations

Purpose

Our aim was to review cost-effectiveness of guideline directed medical therapy of heart failure in India and identify drugs that can be made available free of cost or at subsidized rates to the patient population.

Methods

Data extracted from ten landmark trials in heart failure was used to compute Number Needed to Treat (NNT) and Cost Needed to Treat (CNT) of drugs used in heart failure, to prevent cardiovascular mortality and heart failure re-hospitalization using HDS Plotter- Incremental Cost Effectiveness Calculator. Since various brands (i.e. trade names) with wide cost range are available in Indian market, the average retail price in Indian Rupees for year 2019 was considered and converted to US dollars and used for the analysis.NNT and CNT of each drug was computed and the cost-effectiveness was analyzed. WHO recommendation of three times per capita GDP was used as the cost effectiveness threshold.

Results

Medications that were labeled as class I for the treatment of heart failure, were included in our analysis. Ivabradine, Valsartan and Angiotensin Receptor Neprilysin inhibitor (ARNi) did not meet the cost effectiveness criteria for preventing cardio-vascular mortality. For prevention of heart failure re-hospitalization, all drugs except ARNi, met the cost effectiveness threshold.

Conclusion

Any future research would need to consider compliance factor along with Willingness to Pay (WTP) to understand the real acceptance of these drugs on the ground in India.

Log prices (in US$) of various HF drugs

Funding Acknowledgement

Type of funding source: None
Trends in ischaemic heart disease and cerebrovascular disease mortality in Europe: an observational study from 1990–2017
Authors: Hammond-Haley M , Hartley A , Essa M , Delago A , Marshall D.C , Salciccioli J.D , Shalhoub J.D
Published: November 2020

Background

Cardiovascular disease remains the leading cause of death worldwide. Previously, we identified a growing disparity between Western and Eastern European countries for mortality from ischaemic heart disease (IHD) and cerebrovascular disease (CVD).

Purpose

To describe current trends in mortality from IHD and CVD.

Methods

IHD and CVD age-standardized death rates (ASDR) for European countries between 1990–2017 were extracted from the World Health Organization mortality database using the International Classification of Diseases 9th and 10th Edition codes. Jointpoint regression analysis was used to describe trends over this period.

Results

Between 1990–2017, IHD mortality declined in all included countries except Croatia (+3% in males and +23% in females). Largest mortality improvements were generally seen in Western European countries, including the Netherlands, UK and Sweden, which saw greater than 65% improvements for both sexes. Estonia was a notable exception, which, after the Netherlands, demonstrated the second highest improvement in mortality (−69% in males, −74% in females). Hungary and Greece saw the smallest improvements in IHD mortality (approximately −12% to −27%). Results of jointpoint regression analysis for selected European countries are shown in Figure 1. In 2017 Lithuania had the highest mortality rate in both males and females (279.4/100,000 and 261.3/100,000, respectively) whilst the Netherlands had the lowest mortality in males and females (32.6/100,00 and 15.3/100,000, respectively). This represents an approximately 8.5-fold difference in IHD mortality in males and a 10.5-fold difference in females between these two countries. CVD mortality declined in all included countries between 1990–2017. Estonia saw the greatest improvements in both males and females (−80.8% and −84.9%, respectively), followed by Austria, Portugal and the Czech Republic (over 70% reductions in both sexes). Bulgaria, Romania and Lithuania saw the smallest reductions (approximately −17% to −33%). In 2017, Bulgaria had the highest CVD mortality rate in both males and females (149.9/100,000 and 113.1/100,000, respectively), whilst the lowest mortality rate was observed in Austria (21.8/100,000 and 19.5/100,000 for males and females, respectively). This represents an approximately 7-fold difference in CVD mortality in males and a 6-fold difference in females between these two countries.

Conclusions

IHD and CVD mortality rates continue to decrease for men and women across Europe. While certain Eastern European countries have demonstrated considerable mortality improvements over this observation period, in general the disparity between Eastern and Western Europe persists, with further work required to understand and address these inequalities.

Squares: male. Circles: female

Funding Acknowledgement

Type of funding source: None
Waddling beyond door to balloon times and impinging true ischemic times with artificial intelligence-guided single lead EKG for STEMI detection
Authors: Mehta S , Niklitschek S , Fernandez F , Villagran C , Vera F , Frauenfelder A , Vieira D , Ceschim M , Quintero S , Pinto G , Vallenilla I , Perez Del Nogal G , Cardenas J , Prieto L , Luna M
Published: November 2020

Background

The present process of STEMI detection is cumbersome as it utilizes outdated equipment and requires a trained technician and an expert cardiologist. We have developed a patient-administered, Artificial Intelligence (AI) guided, Single Lead EKG for early STEMI detection.

Purpose

To answer the question “Is early STEMI detection possible with a Single Lead EKG?”

Methods

We experimented with an AI-guided algorithm for a single-lead EKG for STEMI detection with the following step-wise developments: 1) An AI algorithm that predictably interprets STEMI using a 12-lead EKG; 2) An AI algorithm for STEMI detection using a single-lead EKG; 3) A methodology for identifying the best single lead to detect STEMI; 4) Advanced AI algorithms for STEMI localization with a single-lead EKG. The AI methodology was as follows: Sample: The mammoth Latin American Telemedicine Infarct Network telemedicine database that provides an umbrella of AMI management to 100 million patients in Brazil, Colombia, Mexico, Chile, and Argentina was queried for cardiologist annotated EKG. A total of 8,511 EKG and 90,592 classified heartbeats were selected for the experiments. Preprocessing: segmentation of each ECG into individual heartbeats. Training & Testing: 90% and 10%, respectively, of the total dataset. Classification: 1-D Convolutional Neural Network; classes were construed for each heartbeat. Performance indicators were calculated per lead.

Results

The algorithm was able to provide an accuracy of 91.9%. Lead V2 yielded the best results among individual leads for STEMI detection.

Conclusions

Early experiments provide a framework for augmenting STEMI detection with the use of AI-guided, single lead techniques. Such approaches seem rational as we target the reduction of true STEMI ischemic times.

Funding Acknowledgement

Type of funding source: None
Identification and functional characterization of circular RNAs in pericytes
Authors: Glaser S , Heumueller A.W , Klangwart M , Wiederer A , John D , Zeiher A.M , Zehendner C.M , Dimmeler S
Published: November 2020

Background

Circular RNAs (circRNAs) are generated by back-splicing. They are known to be robustly expressed in a variety of mammalian cell types and organism and have been reported to influence cell biology by acting e.g. as microRNA sponges or regulating host gene expression. Recently, our group reported functionally relevant circRNA expression in endothelial cells. Despite their important role in the cardiovascular system, the expression and function of circRNAs in pericytes is not well studied. Pericytes are perivascular mural cells, important for vessel maturation and endothelial barrier function. Their recruitment towards endothelial cells is mainly meditated by platelet-derived growth factor (PDGF) signaling. However, a more precise understanding of the regulation of pericyte differentiation and survival is necessary.

Objective

Here, we analyse circRNA expression in pericytes and demonstrate biological relevance of the hypoxia regulated circular RNA PLOD2 (cPLOD2).

Methods and results

Using RNA Sequencing in ribosomal depleted RNA we characterized the expression of circRNAs in human pericytes under normoxic and hypoxic (1% O2, 48h) conditions. We identified several circular RNAs being regulated upon hypoxia. The identified circular RNAs demonstrated resistance towards RNase-R digestion and lacking of poly-adenylation. Some of them were found to be localized and in the cytosol, whereas others also occur in the nucleus of the cells. Especially cPLOD2 raised our attention since it is significantly upregulated and robustly expressed upon hypoxia. Silencing cPLOD2 by siRNA resulted in significant de-differentiation of pericytes that went along with a loss of cell viability. Mechanistically, transcription factor screening assays revealed that silencing of cPLOD2 enhances the activity of the transcription factors ELK1/SRF, which have been documented to result in de-differentiation of smooth muscle cells.

Conclusion

Here we characterize the expression pattern of circRNAs in human primary pericytes. Among others, cPLOD2 significantly regulates pericyte function. Our results indicate hypoxia as a major regulator of circRNA expression in pericytes and show that circRNAs are capable of regulating pericyte function by modulating activity of transcription factors.

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): Deutsche Forschungsgesellschaft (DFG) - SFB834; Deutsche Gesellschaft für Herz-Kreislaufforschung (DZHK)
Phosphorylation of mitophagic receptor protein Bcl2-like protein 13 plays an important role in maintaining cardiac function under pressure overload
Authors: Murakawa T , Otsu K
Published: November 2020

The most prominent role for mitochondria is to supply the cell with metabolic energy in the form of ATP generated by oxidative phosphorylation. Therefore, the quality control of mitochondria is essential for the maintenance of normal cellular functions. Accumulation of damaged mitochondria is characteristic of various diseases including heart failure. Damaged mitochondria are removed by a mitochondria-specific autophagy, called mitophagy.

Recently, we identified Bcl2-like protein 13 (Bcl2-L-13) as a mammalian functional homolog of Atg32, which is an essential mitophagy receptor in yeast. Bcl2-L-13, localized in outer mitochondrial membrane, induces mitochondrial fragmentation and mitophagy in HEK293 cells. Bcl2-L-13 induces mitophagy through the binding with microtubule-associated protein 1A/1B-light chain 3 (LC3).

We attempted to elucidate the activation mechanism of Bcl2-L-13-mediated mitophagy. Ser272 is close to the LC3 interacting motif in Bcl2-L-13. Overexpression of Bcl2-L-13 induced its Ser/Thr phosphorylation in HEK293 cells. The phosphorylation level of Bcl2-L-13 S272A was significantly attenuated compared with wild-type Bcl2-L-13, suggesting Ser272 is one of the phosphorylation sites. GST-pull down assay revealed that Bcl2-L-13 S272A showed less ability for binding with LC3, while immunocytochemical analysis using anti-ATP synthase and anti-LC3B antibodies showed that the mutant induced less mitophagic activity.

Next, we generated sheep polyclonal antibody for the detection of Bcl2-L-13 phosphorylated at Ser272. The antibody recognized wild-type Bcl2-L-13 but not Bcl2-L-13 S272A mutant. The phosphorylation level of Bcl2-L-13 at Ser272 was upregulated in wild-type hearts 4 weeks after transverse aortic constriction (TAC). In order to examine the in vivo role of the phosphorylation, we generated Bcl2-L-13 S272A mutant knock-in mice. The mice showed no abnormal cardiac phenotypes at baseline. However, the knock-in mice showed significantly larger left ventricular end-diastolic and end-systolic dimensions and lower fractional shortening than wild-type mice 4 weeks after TAC.

Taken together, the phosphorylation of Ser272 in Bcl2-L-13 regulates its mitophagic activity and plays an important role in maintaining cardiac function under pressure overload.

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): British Heart Foundation
Curcumin-loaded extracellular vesicles endowed with heart targeting properties facilitate treatment of myocardial infarction
Authors: Kang J.Y , Kim H.E , Mun D.S , Yun N.R , Joung B.Y
Published: November 2020

Background

Myocardial infarction (MI) is a public health problem and a leading cause of death worldwide. Due to insufficient current treatments, it is essential to develop effective alternatives for MI treatment. Curcumin is known to exhibit a variety of protective effects on the cardiovascular system such as MI, hypertension, and diabetic cardiomyopathy. However, due to its low solubility/stability and quick systemic elimination, curcumin has limited bioavailability. Extracellular vesicles (EVs) have lately emerged as a promising drug delivery vehicles by overcoming drug delivery hurdles. However, strategies are needed for delivery of EVs into the heart avoiding accumulation of other organs.

Purpose

The aim of this study is to investigate whether curcumin-loaded EVs functionalized with cardiac targeting peptide (CTP) may function as efficient heart-targeted delivery vehicles of curcumin, and further identify the molecular mechanisms underlying curcumin-mediated therapeutic effects in the MI.

Methods

EVs functionalized to express CTP (CTP-EVs) were isolated from culture medium of HEK293 cells transfected with mCherry-CD81–10 plasmid and CTP-LAMP2 plasmid by differential centrifugation, and then loaded with curcumin by coincubation, named CTP-EVs-Cur. The effect of CTP-EVs-Cur were evaluated H9C2 cardiomyocytes and mouse MI model. For the in vivo experiments, CTP-EVs-Cur (approximately 8–10 × 109 particles) were administered by intravenous injection into the tail vein and mice were subjected to the left anterior descending (LAD) artery ligation with a 6–0 silk suture.

Results

CTP-EVs were safely and successfully delivered curcumin to H9C2 cardiomyocytes and mouse hearts (4-fold; P<0.05), and CTP-EVs-Cur have a protective effect against MI in vitro and in vivo models. After validating potential utility of CTP-EVs-Cur in MI treatment, we investigated the mechanism of curcumin-mediated recovery effects after MI. In H2O2 treated-cardiomyocytes, curcumin significantly reduced apoptosis by regulating the PTEN/AKT pathway following upregulation of miR-144-3p expression. Furthermore, mice injected with CTP-EVs-Cur reduced infarct size and apoptosis with the regulation of miR-144-3p/PTEN/Akt pathway.

Conclusion

These findings suggest highly stable/effective ability of CTP-EVs for heart-targeted delivery and the novel mechanism of curcumin-mediated cardioprotective effects after MI, therefore, CTP-EVs-Cur are potentially powerful therapeutic strategy for MI treatment.

Funding Acknowledgement

Type of funding source: None
Small extracellular vesicles from epicardial fat of patients with atrial fibrillation induce inflammation, fibrosis and re-entrant arrhythmias
Authors: Shaihov-Teper O , Ram E , Brzezinski R , Volvovitch D , Zuroff E , Amunts S , Schary Y , Naftali-Shani N , Ballan N , Gepstein L , Sternik L , Raanani E , Leor J
Published: November 2020

Background and aim

Epicardial fat (eFat) has been linked to atrial remodeling and fibrillation (AF). Small extracellular vesicles (sEVs) are heterogeneous membrane vesicles released by all cell types. They can both protect and damage tissues by the delivery of multiple different messengers. Surprisingly, the role of sEVs in the pathogenesis of AF has not been studied. Thus, we aimed to determine whether sEVs derived from eFat play a role in the pathogenesis of AF.

Methods and results

We collected eFat specimens from patients with and without chronic or paroxysmal AF undergoing open-heart surgery. Isolated eFat specimens were cut into small pieces and incubated as organ cultures. We isolated sEVs from the medium of the explant by differential ultra-centrifugation, high-density gradient or size exclusion chromatography (SEC), and characterized vesicle size distribution, morphology, specific markers, histology and molecular cargo. Immunostaining for macrophage accumulation, fibrosis and apoptosis confirmed the pro-inflammatory and pro-fibrotic properties of eFat sEVs from patients with AF (Fig. 1). eFat sEVs labeled with PKH26 were massively up taken by endothelial cells (Fig. 2). Real-time PCR showed an increased level of oxidative stress genes in endothelial cells. eFat sEVs from patients with AF caused more fibrosis after injection into rat hearts than those without AF. (Fig. 3). Finally, while eFat sEVs from patients with and without AF induced shorter action potential duration, only eFat sEVs from patients with AF induced sustained re-entry (rotor) in human induced pluripotent stem cell (iPS)-derived cardiomyocytes (Fig. 4)

Conclusion

We show, for the first time, that sEVs from eFat of patients with AF demonstrate unique pro-inflammatory, pro-fibrotic and pro-arrhythmic properties. Our findings suggest that eFat sEVs can induce cellular, molecular and electrophysiological remodeling that can subsequently lead to the development of AF.

Funding Acknowledgement

Type of funding source: None
Mechanical load modulates the cargo of secreted extracellular vesicles (EVs) from living myocardial slices
Authors: Nicastro L , Catapano F , Nunez Toldra R , Floriano J , Oliveira C.C , Emanueli C , Terracciano C.M.N
Published: November 2020

Introduction

Mechanical overload plays an important role in the progression of chronic heart failure (CHF). Beside the numerous neurohormonal and chemical stimuli that contribute to structural and functional changes in the myocardium, intercellular communication mediated by extracellular vesicles (EVs), also plays a pivotal role in disease progression. Exosomes are a subset of EVs ranging between 30–150 nm; these mediators carry molecular cargoes such as miRNAs, mRNAs, DNA and several proteins. However, it is still unclear how specific pathological stimuli may induce a change in their release from tissues or a difference in their cargo content.

Living myocardial slices (LMS) are ultra-thin sections of heart tissue, ranging from 100–400 μm in thickness. They retain the multicellularity, electromechanical physiology, biochemistry and extracellular matrix of the adult heart.

Purpose

To investigate whether mechanical load influences both the released amount and content of LMS-derived exosomes after 24 hours culture.

Methods and results

LMS were prepared from the left ventricle of male Sprague Dawley rats using a high precision vibratome. LMS were stretched in the direction of the muscle fibers at a sarcomere length (SL) of 2.2 μm to recapitulate physiological preload, and at 2.4 μm SL to recapitulate a condition of volume overload. LMS were cultured for 24 hours under electromechanical stimulation. Media containing LMS-derived exosomes was harvested after culture and processed for exosome isolation by size exclusion chromatography columns. Particle size and concentration were assessed by nanoparticle tracking analysis and protein quantity by microBCA assay. There was no significant difference in the size of exosomes between overload and physiological conditions, with an average mean size of 113.475±8.35 nm for the physiological and 129.3±16.35 nm for the overload condition (p=0.61; n=4 physiological; n=3 overload). Although there was not significant difference in exosome amount between physiological and overload condition, (7.00E+10±2.53E+09 vs 1.04E+11±5.77E+09 particles/ml) (p=0.57; n=4 physiological; n=3 overload), exosomes released from overloaded LMS showed a significant increase in protein content compared to physiologically loaded LMS (150.57±25.682 vs 66.045±9.855 μg/ml) (p=0.04; n=3 overload; n=2 physiological).

Conclusions

Mechanical load influences the cargo content of EVs secreted from LMS after 24 hours culture under electromechanical stimulation. Understanding how mechanical load correlates with specific cargoes in EVs will reveal novel therapeutic targets for the treatment of CHF.

Funding Acknowledgement

Type of funding source: Private grant(s) and/or Sponsorship. Main funding source(s): British Heart Foundation (BHF)
The crucial roles of coagulation factors in inducing brown adipose tissue dysfunction and systemic metabolic disorder in obesity
Authors: Hayashi Y , Shimizu I , Yoshida Y , Katsuumi G , Suda M , Fujiki S , Minamino T
Published: November 2020

The prevalence of obesity is increasing worldwide. Obese individuals are predisposed to cardio-metabolic disorders. Brown adipose tissue (BAT) is an active metabolic organ abundant with mitochondria, and studies suggest a potential role of BAT in the maintenance of metabolic health in rodents and humans. Metabolic stress causes BAT dysfunction, but the underlying mechanisms are largely unknown. Coagulation factor Xa (FXa) is critically involved in a coagulation cascade, and it is also known to mediate biological effects by the activation of protease-activated receptor (PAR)-signaling. Accumulating evidence shows that PAR1 contributes to tissue remodeling in cardiovascular system. Analyzing deposited microarray data, we found transcripts for coagulation factors including factor VII (F7), factor X (F10), and PAR1 receptor were increased in BAT from obese mice. Here we show a previously unknown role of FXa-PAR signaling in promoting BAT dysfunction and systemic metabolic disorder in a murine dietary obese model.

Imposing a high fat diet (HFD) on C57BL/6NCr mice led to a marked increase in tissue factor (TF), coagulation factor VII and FXa in BAT. TF-FVIIa (activated form of FVII)-FXa complex is known to activate PAR1, and we found a significant increase in PAR1 expression in BAT upon metabolic stress. Administration of a FXa inhibitor ameliorated BAT whitening, improved thermogenic response and systemic glucose intolerance upon dietary obesity. Fxa inhibition reduced reactive oxygen species (ROS) level in BAT. In contrast, administration of warfarin did not show any phenotype in BAT. BAT specific TF and PAR1 over-expression model showed significant whitening of this tissue, which was associated with systemic glucose intolerance. We generated BAT specific PAR1 KO mice. BAT-PAR1 KO mice exhibited re-browning of BAT along with reduced ROS level in this tissue. In BAT-PAR1 KO mice, glucose intolerance and thermogenic response under a metabolically stressed condition were ameliorated. In differentiated brown adipocytes, FXa markedly increased mitochondrial ROS and reduced mitochondrial membrane potential. Inhibition of PAR1 ameliorated FXa-induced mitochondrial ROS production and reduction in membrane potential. We also found that plasma FXa level did not increase in obese mice as well as in obese individuals. These results suggest the previously unknown role of coagulation systems in promoting BAT dysfunction, leading to systemic metabolic disorders. Maintenance of BAT homeostasis through the suppression of FXa-PAR1 signaling would become a new therapeutic target for obesity and diabetes.

Funding Acknowledgement

Type of funding source: None
PCSK9 is associated with disease activity and implicated in immune activation and cardiovascular disease in Systemic Lupus Erythematosus
Authors: Frostegard J , Frostegard J , Rahman M , Hafstrom I , Ajeganova S , Liu A
Published: November 2020

Background

The risk of atherosclerosis and cardiovascular disease (CVD) is very high in SLE. This is both a clinical problem and of interest in studies of immunity in these conditions. LDL-levels are increased by Proprotein convertase subtilisin kexin 9 (PCSK9) which targets the LDL-receptor (LDLR). We recently reported that PCSK9 ameliorates dendritic cell (DC) activation by oxidized LDL (OxLDL), which is abundant in atherosclerotic plaques and also raised and associated with cardiovascular disease (CVD) in SLE. We here investigate the role of PCSK9 in SLE.

Methods

PCSK9-levels were determined by ELISA among SLE patients (n=109) and age- and sex-matched population-based controls (n=91). Common carotid intima-media thickness (IMT) and plaque occurrence were determined by B-mode ultrasound. Plaques were graded by echogenicity. Human peripheral blood monocytes from SLE patients or controls were differentiated into DCs. Effects of PCSK9 and its inhibition by silencing were studied.

Results

PCSK9-levels were non-significantly higher among SLE-patients as compared to controls but associated significantly with SLE disease activity, as determined by SLAM (0.020) or SLEDAI (0.0178). There was no association between PCSK9-levels and atherosclerosis as determined by IMT, prevalence of plaques or echolucent (potentially vulnerable) plaques. PCSK9 levels were significantly associated with CVD among SLE-patients.

OxLDL induced PCSK9 in DCs and DC-maturation with increased expression of CD86 and HLA-DR. The effects were significantly stronger in DC from SLE patients than from controls. Silencing of PCSK9 abolished OxLDL-induced DC-maturation.

Conclusions

PCSK9 is associated with disease activity in SLE. One underlying cause could be OxLDL, promoting DC-activation which depends on PCSK9. OxLDL induces PCSK9, an effect which is higher among SLE-patients. PCSK9 could play an unexpected immunological role in SLE.

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): Amgen; Swedish Heart and Lung Foundation
MicroRNA-146a regulates angiogenesis and functional regeneration after myocardial infarction
Authors: Knoepp K , Teske R , Korte L , Dutzmann J , Rieckmann M , Daniel J.M , Thum T , Bauersachs J , Sedding D.G
Published: November 2020

Background

The growth or regeneration of new blood vessels is critical for physiological angiogenesis and for tissue repair in response to injury, such as myocardial infarction. However, the mechanisms underlying the angiogenic processes and, specifically, the regulation of neo-vascularization by microRNAs are not well understood.

Purpose

To study the potential beneficial role of miRNA-146a in vessel regeneration after myocardial infarction.

Methods

Mice were subjected to myocardial infarction or hind limb ischemia and vascular development was followed in zebra fish. microRNA-146a was blocked or overexpressed in endothelial cells in vitro or in mice or zebra fish in vivo. Furthermore, Blood samples from patients with ST-elevation myocardial infarction (STEMI) were studied for miR-146a expression.

Results

MicroRNA-146a was upregulated in the ischemic hind limb following ligation of the femoral artery and in the ischemic myocardium in male C57BL/6 mice following ligation of the left anterior descending (LAD) artery, as well as in patients with STEMI. In vitro, overexpression of microRNA-146a significantly attenuated endothelial cell proliferation and migration, abolished endothelial capillary network formation, and inhibited cell sprouting from endothelial spheroids. In contrast, microRNA-146a silencing had opposite effects. Mechanistically, Nox4, Notch1, and nRas were identified by in silico prediction and microarray mRNA expression analysis, and validated as direct targets and effector molecules of microRNA-146a in endothelial cells according to mRNA and protein expression profiles, as well as luciferase gene reporter assays and respective rescue experiments. In zebrafish, overexpression of microRNA-146a inhibited the development of the trunk vasculature. Blocking the upregulation of endothelial microRNA-146a in mice,using specific inhibitors, resulted in significantly enhanced 1 angiogenesis and revascularization both in an ischemic hind limb model and in the infarcted myocardium. This was accompanied by a significantly reduced myocardial infarct size and preserved cardiac function post MI.

Conclusions

Our findings identify microRNA-146a as a critical regulator of angiogenesis and vascular regeneration. Inhibition of microRNA-146a may represent an attractive strategy for the angiogenic therapy of ischemic tissue diseases.

Funding Acknowledgement

Type of funding source: None
Implication of anti-angiogenic VEGF-A165b in angiogenesis and systolic function after reperfused myocardial infarction
Authors: Marcos Garces V , Rios-Navarro C , Hueso L , Diaz A , Bonanad C , Ruiz-Sauri A , Sanz M.J , Chorro F.J , Piqueras L , Bodi V
Published: November 2020

Background

Angiogenesis participates in re-establishing microcirculation after myocardial infarction (MI).

Purpose

In this study, we aim to further understand the role of the anti-angiogenic isoform vascular endothelial growth factor (VEGF)-A165b after MI and explore its potential as a co-adjuvant therapy to coronary reperfusion.

Methods

Two mice MI models were formed: 1) permanent coronary ligation (non-reperfused MI), 2) transient 45-min coronary occlusion followed by reperfusion (reperfused MI); in both models, animals underwent echocardiography before euthanasia at day 21 after MI induction. Serum and myocardial VEGF-A165b levels were determined. In both experimental MI models, functional and structural implication of VEGF-A165b blockade was assessed. In a cohort of 104 ST-segment elevation MI patients, circulating VEGF-A165b levels were correlated with cardiovascular magnetic resonance-derived left ventricular ejection fraction at 6-months and with the occurrence of adverse events (death, heart failure and/or re-infarction).

Results

In both models, circulating and myocardial VEGF-A165b presence was increased 21 days after MI induction. Serum VEGF-A165b levels inversely correlated with systolic function evaluated by echocardiography. VEGF-A165b blockage increased capillary density, reduced infarct size, and enhanced left ventricular function in reperfused, but not in non-reperfused MI experiments. In patients, higher VEGF-A165b levels correlated with depressed ejection fraction and worse outcomes.

Conclusions

In experimental and clinical studies, higher serum VEGF-A165b levels associates with a worse systolic function. Its blockage enhances neoangiogenesis, reduces infarct size, and increases ejection fraction in reperfused, but not in non-reperfused MI experiments. Therefore, VEGF-A165b neutralization represents a potential co-adjuvant therapy to coronary reperfusion.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): This study was funded by “Instituto de Salud Carlos III” and “Fondos Europeos de Desarrollo Regional FEDER” (Exp. PIE15/00013, PI17/01836, PI18/00209 and CIBERCV16/11/00486).
Purification of human iPSC-derived cardiomyocytes by HDAC inhibition through inducing apoptosis and cell arrest in non-cardiomyocytes
Authors: Tanaka A , Watanabe K , Kondo S , Tamura N , Nishimoto T , Yoshida Y
Published: November 2020

Background

Cell therapy is one of the most promising strategies for treatment of heart failure. During preparation of iPSC-derived cardiomyocytes for cells therapy, it is important to eliminate the presence of residual proliferative non-target cells in the preparation as these non-target cells could present the risk of tumorgenicity. To minimize the risk, selective and more precise purification process is necessary.

Purpose

We hypothesized that the differences in proliferative activity between cardiomyocytes and non-target cells might result in different sensitivities to the drugs targeting cell growth/survival. The aim of this study is to obtain compounds that eliminate non-cardiomyocytes selectively and to study the mechanism of action of these compounds.

Methods and results

We screened 314 small compounds using both iPSCs and sorted hiPSC-derived cardiomyocytes (hiPSC-CMs). We identified several compounds, which markedly decreased the cell numbers of iPSCs, but showed minimum effects on those of hiPSC-CMs. Among them, HDAC inhibitors were selected as the most promising candidates. We examined whether HDAC inhibitors could purify hiPSC-CMs containing non-cardiomyocytes populations, which were differentiated using the classical embryoid body (EB) method. As a result, HDAC inhibitors increased the purity of cardiomyocytes (up to 98%) by decreasing non-target cells such as smooth muscle cells, endothelial cells, and endodermal lineage cells. Moreover, we confirmed HDAC inhibitors could be used for purification of cardiomyocytes in monolayer differentiation protocol using GSK3β inhibitor and Wnt inhibitor. We measured the expression levels of mRNA and protein in iPSCs and hiPSC-CMs (EB method) treated with HDAC inhibitors. mRNA levels of CDKN1A (p21) and BAX were upregulated in iPSCs. Western blotting analyses revealed that HDAC inhibitors also induced the expression of p21 and the cleavage of Caspase3 in iPSCs.

Conclusions

Our result suggests that the inhibition of HDAC enables an efficient purification of hiPSC-CMs in multiple differentiation methods. Furthermore, our data indicate that HDAC inhibitors induce the apoptosis and cell cycle arrest in iPSCs but not hiPSC-CMs.

Figure 1

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): Takeda Pharmaceutical Company Limited
Bioinspired cell-derived nanovesicles protect the heart from ischemia reperfusion injury
Authors: Wang J , Huang C.Y , Neupane Y.R , Wang X , Zharkova O , Chong S.Y , Lee C.K , Wacker M.G , Storm G , Pastorin G
Published: November 2020

Introduction

Exosomes have been proven to alleviate myocardial ischemia reperfusion (I/R) injury in preclinical studies. However, the laborious and low-yield production process of naturally secreted exosomes has been impeding their translation into clinical trials.

Purpose

We aim to develop a simple and cost-effective protocol to produce exosome mimetics, bioinspired Cell-Derived Nanovesicles (CDNs), and examine their intrinsic bioactivity in a mouse model of I/R injury.

Methods

CDNs were produced from human U937 monocytes using cell shearing approach and characterized by dynamic light scattering (DLS), nanoparticle tracking analysis (NTA) and transmission electron microscopy (TEM). Lipid composition of cells and CDNs was analysed by lipidomics. I/R injury was induced by transient occlusion of left coronary artery. Data was analysed with Mann-Whitney U test. P<0.05 was considered statically significant.

Results

We obtained 538 mg (protein content) of CDNs, or 3x109 CDNs, via cell shearing approach from 2×107 cells, approximately 15 folds of exosomes via natural secretion from the same number of cells. CDNs were 125±8 nm in diameter with negative surface charge (zeta potential −7.0±0.8) and presented as double-membranous vesicles under TEM. In vitro, CDNs showed strong antioxidant activity and could be taken up by bone marrow-derived macrophages. Following intravenous administration, as demonstrated by the IVIS Spectrum imaging system, CDNs accumulated specifically in the infarct area of the heart within 3 hours. Compared with saline treatment, CDNs reduced myocardial infarct size by 31.6% (p<0.01) after 24 hours of I/R injury. Intriguingly, CDNs generated from human mesenchymal stem cells showed similar therapeutic efficacy. Mechanistically, CDNs inhibited infiltration of inflammatory cells (macrophages) and promoted upregulation of the anti-inflammatory cytokine interleukin 10 (IL10) in the I/R injured hearts. In the blood stream, CDNs increased IL10 protein level and exerted antioxidant activity. Furthermore, CDNs reduced I/R injury-induced cell apoptosis in the myocardium.

Conclusion

We have established a cost-effective approach to produce exosome mimetics, bioinspired CDNs, which protect the heart from I/R injury via inhibition of inflammation, oxidative stress and cardiac cell apoptosis. CDNs have intrinsic cardioprotective capability in heart injury, comparable to exosomes.

Funding Acknowledgement

Type of funding source: Public Institution(s). Main funding source(s): National University Health System.