bluuebunny/crossref_metadata_2025 huggingface dataset:
Incidence in atrial fibrillation in Denmark in relation to country of origin: a nationwide register-based study
Authors: Frydenlund J , Valentin J , Norredam M , Riahi S , Kragholm K , Boggild H , Johnsen S
Published: October 2022

Background

Immigrants' healthcare needs can be a considerable challenge, as their risk profile can differ from the native population, and they may experience barriers to accessing health services in recipient countries. Immigration is projected to increase further due to conflicts and climate changes, and awareness on immigrants' health status is therefore warranted. Atrial fibrillation (AF) is the most common sustained arrhythmia with an estimated prevalence of approximately 2%. However, there is a paucity of data on AF epidemiology among immigrants.

Purpose

The aim of this study is to examine incidence of AF hospital diagnoses according to country of origin and to study if there is a difference in risk between immigrants and Danish born individuals.

Methods

The study period included 1st of January 1998 to 31st of December 2017 and the population consisted of all Danish citizens aged 45 or older. We included individuals as they turned 45 during the study period. Individuals who had been diagnosed with AF were excluded. Data was obtained from the Danish National Patient Registry and the Civil Registration System. Country of origin was based on the ten most represented counties in the population. Immigrants were defined as people born outside Denmark with none of the parents being both Danish citizens and born in Denmark. AF was defined as a hospital diagnosis according to international Classification of Diseases (ICD) version 8 and 10. Poisson regression were used to compute relative risk (RR) and associated 95% confidence intervals (CI). RRs were adjusted for sex, age, socioeconomic status, visits to general practitioner and comorbidity.

Results

The study population consist of 3,596,234 Danish-Born and 215,401 immigrants. A total of 334,636 had an incident AF diagnosis during the study period. Compared to Danish-born individuals, migrants from the Nordic countries had a higher adjusted RR of being diagnosed with AF: Norway 1.21 [95% CI: 1.05; 1.40], Sweden 1.16 [95% CI: 0.99; 1.35] and Germany 1.17 [95% CI: 1.06; 1.28]. In contrast, lower adjusted RRs were observed for individuals from Poland (0.82 [95% CI: 0.67; 1.01]), UK (0.89 [95% CI: 0.73; 1.08]), and the US (0.95 [95% CI: 0.72; 1.25]), respectively, and in particular for individuals from the non-Western countries: Turkey (0.49 [95% CI: 0.40; 0.59], Iran (0.48 [95% CI: 0.36; 0.65]), Iraq (0.32 [95% CI: 0.22; 0.45] and Bosnia-Herzegovina (0.63 [95% CI: 0.49; 0.79]).

Conclusion

Substantial variation in the incidence rate of incident AF hospital diagnoses according to country of origin. Further studies are warranted in order to clarify to what extent these differences reflets true differences in AF incidence or ethnic inequalities in the detection of AF in the health care system.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Karen Elise Jensen Foundation
Cost-effectiveness of clopidogrel versus ticagrelor in patients of 70 years or older with non-ST-elevation acute coronary syndrome
Authors: Van Den Broek W W A , Van Paassen J G , Gimbel M E , Deneer V H M , Ten Berg J M , Vreman R A
Published: October 2022

Background/Introduction

In older patients with non-ST-elevation acute coronary syndrome (NSTEMI) the POPular AGE trial clopidogrel showed superiority to ticagrelor in reducing bleeding risk and non-inferiority in net clinical benefit (all-cause death, myocardial infarction, stroke, and PLATelet inhibition and patient Outcomes; major or minor bleeding).

Purpose

The aim of this analysis was to estimate the long-term cost-effectiveness of clopidogrel compared to ticagrelor in these older patients with NSTEMI and to address the impact on quality of life by both treatment strategies.

Methods

A 1-year decision tree based on the POPular AGE trial in combination with a lifelong Markov model was developed to compare clopidogrel with ticagrelor in terms of clinical outcomes, costs and quality-adjusted life years (QALYs) in elderly patients (above 70 year) with NSTEMI. Cost-effectiveness was assessed from a Dutch healthcare system perspective. Events rates and utility data observed in the POPular AGE trial were combined with lifetime projections to evaluate cost and effects for a fictional cohort of 1000 patients. Deterministic, probabilistic sensitivity analyses and several scenario analyses were performed. The several scenario's included different time horizons, identical prices for P2Y12-inhibitors, different health utilities in the clopidogrel and ticagrelor arm and a prolonged duration of bleeding disutility.

Results

Treatment with clopidogrel instead of ticagrelor led to a cost saving of €1,482,775 (€1,483 per patient) and a decrease of 10,96 quality-adjusted life years (QALY's) (0.011 QALY per patient) in the fictional cohort. In an alternative base case with equal distribution over health states in the first year based on the non-inferiority of the POPular AGE trial, treatment with clopidogrel was the dominant strategy both cost saving and increasing QALY's. In all scenario analyses, treatment with clopidogrel was cost saving. In the scenario with different health utilities in the clopidogrel and ticagrelor arm, the distinct average reported health utilities in both treatment arms were used. In this scenario clopidogrel was the dominant strategy.

Conclusion

This analysis shows that clopidogrel is a cost-saving alternative to ticagrelor in elderly patients after NSTEMI, with a very small negative effect on QALY's. It supports the conclusion of the POPular AGE trial to regard clopidogrel as a favourable alternative to ticagrelor in the elderly patient after a NSTEMI.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): ZonMw
Impact of COVID-19 on cardiac procedure activity in England and associated 30-day mortality
Authors: Mohamed M , Banerjee A , Clarke S , De Belder M , Goodwin A , Gale C , Curzen N , Mamas M
Published: October 2022

Background

The COVID-19 pandemic had a significant impact on the quality of healthcare provision across all specialities and disciplines. However, there are limited data on the scale of its disruption to cardiac procedure activity from a national perspective and whether procedural outcomes different before and during the COVID-19 pandemic.

Methods

Major cardiac procedures (n=374,899) performed between 1st January and 31st May for the years 2018, 2019 and 2020 were analysed, stratified by procedure type and time-period (pre-COVID: January-May 2018 and 2019 and January-February 2020 and COVID: March-May 2020). Multivariable logistic regression modelling was undertaken to examine the odds ratio (OR) of 30-day mortality for procedures performed in the COVID period (vs. pre-COVID).

Results

There was a deficit of 45,501 procedures during the COVID period compared to the monthly averages (March-May) in 2018–2019. Cardiac catheterisation and cardiac electronic device implantations were the most affected in terms of numbers (n=19,637 and n=10,453) while surgical procedures including mitral valve replacement, other valve replacement/repair, atrial and ventricular septal defect repair, and CABG were the most affected as a relative percentage difference (D) to previous years' averages. TAVR was the least affected (D-10.6%). No difference in 30-day mortality was observed between pre-COVID and COVID time-periods for all cardiac procedures except cardiac catheterisation (OR 1.25 95% confidence interval (CI) 1.07–1.47, p=0.006) and cardiac device implantation (OR 1.35 95% CI 1.15–1.58, p<0.001).

Conclusion

There was a significant decline in national cardiac procedural activity in England during the COVID-19 pandemic, with a deficit in excess of 45000 procedures over the study period. However, there was no increase in risk of mortality for most cardiac procedures performed during the pandemic. While health service pressures are gradually easing given the increased roll out of vaccination and decline in infection rates, there is a need for major restructuring of cardiac services deal with this significant backlog of procedures, which would inevitably impact longer-term morbidity and mortality.

Funding Acknowledgement

Type of funding sources: None.
Association of late gadolinium enhancement in cardiac magnetic resonance with heart failure outcomes in patients with non-ischemic cardiomyopathy
Authors: Tao M , Al-Sadawi M , Aslam F , Mann N , Goldschmidt M , Tam E
Published: October 2022

Background

Late-gadolinium enhancement (LGE) in cardiac magnetic resonance (CMR) has been found to be associated with increased mortality in patients with non-ischemic cardiomyopathy (NICM). The correlation between LGE and heart failure (HF) hospitalization, referral for heart transplant, and ejection fraction (EF) improvement have not been well established.

Purpose

This meta-analysis assessed the relationship between LGE in CMR with HF hospitalization, referral for heart transplant and EF improvement in patients with NICM.

Methods

We searched the databases for studies reporting the association between LGE in CMR for NICM and HF outcomes including Ovid MEDLINE, EMBASE, Web of Science, and Google Scholar for all studies. The search was not restricted to time or publication status. The minimal follow up duration is one year.

Results

A total of 216 studies resulted from the literature search. A total of 25 studies and 3,039 patients (1,265 with LGE vs 1,774 without LGE) were included; mean follow up is around 33 months (ranging between 13 to 71 months). Our analysis demonstrated that LGE in NICM was associated with increased risk of HF hospitalization (odds ratio 3.38, 95% confidence interval 2.27–5.04; P<0.01), referral for transplant (odds ratio 5.08, 95% confidence interval 2.49–10.35; P<0.01), and lower chance for EF improvement (odds ratio 0.16, 95% confidence interval 0.03–0.85; P 0.03). Heterogeneity is moderate: χ2=49.5, df=21 (P=0.001), I2=57%. (Figures 1 and 2)

Conclusions

Our results suggest that LGE is associated with increased risk of HF hospitalization and referral for heart transplant and lower chance for EF improvement in long-term follow up.

Funding Acknowledgement

Type of funding sources: None.
AT-RISK: AuToimmune disorders and cardiovascular RISK
Authors: Conrad N , Verbeke G , Molenberghs G , Goetschalckx L , Callender T , Rahimi K , Mason J C , McMurray J J V , Verbakel J Y
Published: October 2022

Background

Increased cardiovascular risk has been suggested for selected autoimmune disorders. Yet, for many conditions, evidence is insufficient to design more targeted prevention measures and guide clinical decisions.

Methods

We used linked primary and secondary electronic health records from the Clinical Practice Research Datalink (CPRD) to assemble a cohort of individuals newly diagnosed with any of 19 autoimmune disorders between 01/01/2000 and 31/12/2017 and free of cardiovascular disorders (CVD) up to 12 months after diagnosis, and up to five individuals matched on age, sex and socioeconomic status, with follow-up until 30/06/2019. We investigated incidence of nine cardiovascular outcomes and used cox-proportional hazards models to examine differences in patients with and without autoimmune disorders accounting for known cardiovascular risk factors.

Findings

We identified 432,883 individuals with autoimmune disorders and 2,159,350 matched controls. Of these, 104,504 people with and 450,195 without autoimmune disorders developed incident CVD during a median of 5.3 [interquartile range: 2.6, 9.6] years of follow-up. Patients with one or more autoimmune disorders had higher risk of cardiovascular outcomes: adjusted hazard ratio (HR) [95% confidence interval (CI)] 1.34 [1.31, 1.37]. This relationship held for every individual cardiovascular disorder and increased progressively with the number of autoimmune disorders present. Among autoimmune disorders, those associated with systemic inflammation, such as type I diabetes (2.09 [1.91, 2.28]), systemic sclerosis (2.90 [2.29, 3.67]) and systemic lupus erythematosus (2.21 [1.96, 2.50]) presented with highest overall cardiovascular risk (Figure).

Interpretation

Autoimmune disorders are associated with a high risk of developing cardiovascular outcomes. These findings warrant targeted cardiovascular prevention measures for patients with autoimmune disorders and further research into pathophysiological mechanisms underlying these complications.

Funding Acknowledgement

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): This project has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie (grant agreement No 843267) and from the European Society of Cardiology (grant number App000037070).
Measurement error in echocardiographic assessment of aortic stenosis: an epidemiological consideration of research methodology and clinical practice
Authors: Velders B J J , Groenwold R H H , Kappetein A P , Braun J , Klautz R J M , Vriesendorp M D
Published: October 2022

Background/Introduction

Current international guidelines on treatment of valvular heart disease contain recommendations for aortic valve replacement based exclusively on abnormal echocardiographic parameters in asymptomatic patients with aortic stenosis (AS). To prevent misclassification and subsequent mistreatment of patients, these recommendations require accurate and unbiased measurements of hemodynamic parameters.

Purpose

To illustrate consideration and impact of measurement error in echocardiographic assessment of aortic stenosis in both the research and clinical setting.

Methods

First, a systematic review was performed to investigate the recognition of and correction for measurement error in clinical studies on the prognostic value of peak aortic jet velocity (Vmax), mean pressure gradient (MPG), and effective orifice area (EOA). Second, all potential erroneous sources in the calculation of those primary parameters were listed stratified to random or systematic measurement error, and subsequently their magnitude was quantified. Third, the impact of various types of measurement error on current thresholds for intervention was graphically illustrated in different clinical scenarios.

Results

The presence of measurement error was acknowledged in 44% of the 36 included studies, while none utilized methods to correct for it. Interobserver variability ranged between 0.9–8.3% for Vmax and MPG but was substantially higher for EOA (range 7.7–12.7%) implying lower reliability (Figure 1). Furthermore, the invalid assumption of a circular left ventricular outflow tract area resulted in a median underestimation in EOA of 22.5% compared to 3D-transesophageal echocardiography (3D-TEE), computed tomography (CT), and cardiovascular magnetic resonance (CMR) planimetry. Figure 2 illustrates the impact of this discrepancy on the classification of AS using one-sided t-tests to determine the areas under the curve; the proportion of patients with non-severe AS in a hypothetical cohort (based on values from the PARTNER 3 trial [1[) increased by 42%.

Conclusion(s)

Measurement error is underrecognized in studies of echocardiographic assessment of aortic stenosis. This review demonstrates that random and systematic measurement errors affect echocardiographic assessment, leading to potential misdiagnosis and subsequent mistreatment. Clinicians and scientists should be aware of the implications of measurement errors to enhance rightful clinical decision-making and assure research validity.

Funding Acknowledgement

Type of funding sources: None.
Medication adherence assessment and reporting in cardiovascular randomised controlled trials
Authors: Ashkir Z , Teoh Z , Ganesananthan S , Ahmed-Jushuf F , Beattie C J , Asher A , Kelshiker M , Howard J , Al-Lamee R
Published: October 2022

Background

Despite the knowledge that suboptimal adherence to medications may have an impact on the impact of treatment interventions, the assessment and reporting of medication adherence in cardiovascular randomised controlled trials has not been well studied. In this review we sought to study the differences in medication adherence assessment and reporting in cardiovascular randomised controlled trials (RCTs) comparing interventional procedures to medical therapy alone in four major cardiovascular conditions: coronary disease (CAD), atrial fibrillation (AF), heart failure (HF) and hypertension (HTN).

Methods

Comprehensive searches of PUBMED/MEDLINE, Clinicaltrials.gov and Cochrane Central Register of Controlled Trials (CENTRAL) were performed. Two independent authors screened and extracted general study data, adherence assessment methodology and adherence reporting characteristics from eligible RCTs.

Results

A total of 568 studies (257 HTN, 120 HF, 116 CAD and 75 AF RCTs) published between 2014–2019 were included in the review. Overall, only 44.7% of RCTs assessed adherence, 14.1% defined “good” adherence and 21.1% reported adherence results. HTN and CAD trials performed significantly better than HF and AF studies in all three parameters. Compared to drug trials, procedural trials were significantly less likely to assess adherence (21.1% vs 45.7%, p<0.001), define good adherence (7% vs 15.5%, p<0.001) or report adherence results (10.5% vs 21.3%, p=0.046). Adherence assessment practices were further significantly influenced by funding, placebo status and study outcome. Pill count/return of packaging was the most utilised method (49.5%) and direct observation the least utilised (1.1%). Adherence was calculated in 55.9% of RCTs with studies using different formulas and setting different thresholds for “good” adherence but most setting this at 80% adherence. Adherence reporting practices also varied significantly between RCTs. Most studies (53%) that assessed adherence, did not in fact report their results.

Conclusion

Our findings expose significant inconsistencies in adherence assessment and reporting practices amongst cardiovascular RCTs. This is a systemic problem with important implications on research quality and reliability. We therefore recommend the incorporation of mandatory adherence assessment and reporting into international reporting guidelines for RCTs such as the CONSORT statement. We also propose a grading system which once validated may be used to appraise standards of adherence assessment and reporting in RCTs.

Funding Acknowledgement

Type of funding sources: None.
Mechanism(s) for age-related sex differences in diet-induced cardiomyopathy: role of RNA methylation
Authors: Croft A , Kelly C , Chen D , Murtha L , Sugito S , Boyle A , Sverdlov A L , Ngo D T M
Published: October 2022

Background/Introduction

Age and sexual dimorphism contribute to the differential cardiometabolic dysfunctions associated with diet-induced obesity. However, the underlying mechanisms remain elusive. RNA modifications via RNA m6A methylation, is an emerging mediator of RNA stability, translation and localization responsible for regulation of multiple biological functions. RNA m6A modifications are regulated by “writers”, “erasers” and “readers”. The role of RNA methylation machinery genes in the heart is largely unexplored, and may provide insight into the influence of age and sex on cardiometabolic dysfunction.

Purpose

We aim to determine differential RNA methylation changes within the heart in a diet-induced cardiomyopathy mouse model, stratified according to age and sex.

Methods

Male and female C57BL/6 mice (6–8wk-old) were fed normal chow (NC) or high-fat/high-sucrose (HFHS) diet for 1 or 4 months. Echocardiographic measurements were performed at 1 and 4 months according to the American Society of Echocardiography and European Association of Cardiovascular Imaging guidelines. At study endpoint, glucose and insulin tolerance testing was conducted by injecting mice intraperitoneally with 2g/kg glucose or 0.6U/kg insulin, and monitoring blood glucose levels over a 2 hour period. RNA from heart tissue was subjected to quantitative PCR for RNA methylation machinery genes (FTO, ALKBH5, METTL3, METTL4, METTL14, YTHDF1 and YTHDF2). PPIA was used to normalise qPCR data.

Results

Both male and female mice showed evidence of age- and diet-induced metabolic dysfunction, however, males and females showed markedly different metabolic impairments. For example, glucose tolerance was exacerbated by 4 months of HFHS diet in males but not females; and only females showed impaired insulin tolerance. Echocardiography showed that males had systolic (stoke volume, cardiac output) and diastolic (E/A ratio) dysfunction after 4 months of HFHS diet, while females were unperturbed. We identified that METTL3 and METTL14, the “writers” of m6A methylation, were consistently increased in male mouse hearts at 1 vs 4 months of age but were unchanged or decreased in females, irrespective of diet. Conversely, YTHDF1, a “reader”, was unchanged in male mouse hearts at 1 vs. 4 months of age but was significantly increased in female hearts.

Conclusion

Our study confirms that markedly different cardiometabolic impairments occur in male versus female mice in response to long-term HFHS diet. Despite significant metabolic impairment in both sexes, cardiac dysfunction was only evident in males. RNA methylation machinery genes were differentially expressed in mouse hearts according to age and sex, suggesting that RNA methylation may be involved in age-related sexual dimorphism in cardiometabolic impairments.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Heart Foundation
LTBP2 mutation may cause mitral valve prolapse
Authors: Durst R
Published: October 2022

Background

Mitral valve prolapse (MVP, MIM 157700) is a very common cardiac disorder occurring in 2.4% of the general population. MVP is characterized by myxomatous degeneration resulting in valve thickening, prolapsing and regurgitation. MVP results in mitral regurgitation, arrhythmias, bacterial endocarditis, congestive heart failure and sudden death. Familial studies of MVP suggest an autosomal dominant mode of inheritance with incomplete penetrance. We are wokring on defining the genetic causes of MVP.

Methods and results

We identified an MVP family with an LTBP-2 Val1506Met rare mutation (minor allele frequency of 0.0001) segregating with the MVP (LOD score of 1.5 out of a maximal potential of 2.6). LTBP2 is an excellent candidate gene for MVP because it regulates TGFβ signaling activity, shown to be disrupted in Marfan's syndrome mitral valvulopathy. High prevalence of MVP was reported in relatives of patients with Weill-Marchesani syndrome, caused by LTBP2 mutations.

We then generated two strains of mice using CRISPR technology. A complete knockout (deletion of the first exon) and a knock in mouse. Nineteen mice were dissected so far (figure 3). None of the wt mice (n=8) demonstrated myxomatous degeneration. Of the 11 mice with mutation, 8 homozygote for deletion and 3 homozygote for the human mutation, 8 demostrated myxomatous Degeneration by histology (1 knockin mouse ∼70% pentrance in male mice, p=0.001, Fisher exact test). The pathologist that read the studies was blinded to the genotype. Echocardiography of theses mice demonstrated findings consistant with MVP (deviation of the leaflets above the annluar line in parasternal long axis view) in 50% of affected mice and not in controls

Conclusion

We demonstrated that an LTBP2 mutation is segretating in a family with MVP. LTBP2 mutation mice model demonstrated myxomatous degeneration of the valve. Thus, LTBP2 may be an MVP causing gene

Funding Acknowledgement

Type of funding sources: Public hospital(s).
Demethylation and reactivation of the fibrosis-suppressor gene Rasal1 is initiated by R-loop formation which facilitates recruitment of TET3 and GADD45g
Authors: Maamari S , Xu X , Zeisberg E
Published: October 2022

Background

Silencing of fibrosis suppressor genes through DNA methylation has been shown to contribute to fibrosis progression in the heart and in other organs. Growth Arrest and DNA Damage 45-(GADD45) and Ten-Eleven-Translocation (TET) proteins are involved in active DNA demethylation, but how they are recruited to the promoter of fibrosis suppressor genes has not yet been understood.

Purpose

To identify the mechanisms involved in site-specific demethylation of the promoter region of the cardiac fibrosis suppressor gene Rasal1.

Methods

We previously identified lncRNA Gm15749 located within the Rasal1 promoter region. Using DRIP qRT-PCR, we demonstrated an enrichment of R-loops at the Rasal1 promoter in non-fibrotic mouse cardiac fibroblasts. Such enrichment of R-loops was lost upon TGF-beta-treatment in activated “fibrotic” fibroblasts, and also upon Gm15749 knockdown in untreated non-fibrotic fibroblasts. ChIP qRT-PCR further revealed binding of GADD45g to the Rasal1 promoter and Co-IP experiments confirmed a physical interaction of TET3 and GADD45g.

Results

Studying the RAS Protein Activator Like 1 (Rasal1), which has been shown to be silenced in fibrosis of the heart due to promoter hypermethylation, we find that the lncRNA Gm15749 within the promoter region of Rasal1 is protective by forming an R-loop at the Rasal1 promoter. Gm15749 mediates the recruitment and binding of GADD45g, which then triggers the demethylation process by recruiting TET3 specifically to the Rasal1 promoter region. During cardiac fibrosis, all three factors; Gm15749, TET3, and GADD45g are significantly downregulated and the protection of Rasal1 is lost due to the failure of the formation of the demethylation complex.

Conclusions

Our results suggest a complex involving an R-loop forming lncRNA termed Gm15749, which interacts with the demethylation complex consisting of GADD45g and TET3 to perform site-specific demethylation at the Rasal1 promoter. Such R-loop formation may counteract fibrogenesis through reactivation of fibrosis-suppressor genes silenced by hypermethylation.

Funding Acknowledgement

Type of funding sources: None.
A large-scale functional high-throughput screening identifies miR-515 and miR-519e as potent inducers of human iPSC-cardiomyocyte proliferation
Authors: Renikunta H V , Lazarow K , Gong Y , Shukla P C , Giral H , Kratzer A , Nageswaran V , Opitz L , Engel F B , Haghikia A , Paneni F , Von Kries J P , Streckfuss-Boemeke K , Landmesser U , Jakob P
Published: October 2022

Introduction

Ischemic heart failure persists as a global health problem despite optimized medical and adjunctive device therapies. Loss of cardiomyocytes in the absence of a proliferative response comprise a major contributor to pathological remodeling and death in this patient population. Experimental studies have shown that microRNAs (miRNAs) may be used as a therapeutic option to reinduce adult cardiomyocyte proliferation.

Purpose

This study thought to evaluate proliferative potential in human cardiomyocytes after overexpression and inhibition of 2019 miRNAs.

Methods

To identify miRNAs that regulate cardiomyocyte proliferation, we performed functional high-throughput screenings in human iPSC-derived cardiomyocytes (hiPSC-CM) after transient hypoxia. Herein, 2019 miRNA-mimics for overexpression and 2019 anti-miRs for inhibition were individually transfected to examine EdU-incorporation in hiPSC-CM. MiR-mimic-515 and miR-mimic-519e that induced the highest EdU-uptake, were further assessed by immunostaining and molecular methods for markers indicative of early and late mitosis. In addition, RNA-Sequencing in hiPSC-CM after overexpression of miR-515 and miR-519e was performed to examine differential gene expression and miRNA-modulated pathways involved in cardiomyocyte proliferation.

Results

Using a functional high-throughput screening, we assessed differential proliferative potential of 2019 miRNAs after transient hypoxia by transfecting both miR-inhibitor and miR-mimic libraries in human iPSC-derived cardiomyocytes (hiPSC-CM). Overexpression of 28 miRNAs substantially induced proliferative activity in hiPSC-CM, with an overrepresentation of miRNAs belonging to the C19MC-cluster and adjacent miR-371–373 family. Two of these miRNAs, miR-515 and miR-519e increased markers of early and late mitosis, with an additive cardiomyocyte turnover after transient hypoxia and substantially increased Aurora B-kinase activity in midbodies, indicative of cell division. These findings were supported by molecular studies using qRT-PCR, Western blot, and RNA-Sequencing after overexpression of miR-515 and miR-519e showing substantial alterations of signaling pathways relevant for cardiomyocytes proliferation in human iPSC-CM.

Conclusion

Collectively, these results support a critical role of miR-515 and miR-519e for induction of proliferation in human cardiomyocytes under hypoxic conditions, such as present in patients with ischemia-driven cardiomyopathy.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): This work was supported by the German Centre for Cardiovascular Research (DZHK), Deutsche Stiftung für Herzforschung (DSHF) and OPO Foundation.
Chronic insulin resistance deteriorates cardiac mitochondrial quality control in a mouse model of SEC-NAFLD-IR
Authors: Lu K , Rothe M , Floegel U , Kotzka J , Oehler D , Roden M , Kelm M , Szendroedi J , Westenfeld R
Published: October 2022

Background

Insulin resistance and nonalcoholic fatty liver disease (NAFLD) both relate to cardiovascular mortality. Using a mouse model of chronic lipid overload and secondary-NAFLD-induced insulin resistance (SEC-NAFLD-IR), we recently deciphered that SEC-NAFLD-IR already at young age provoked myocardial lipotoxicity with reduced mitochondrial efficiency and increased vulnerability to cardiac ischemia. However, long-term consequences of SEC-NAFLD-IR remain elusive.

Purpose

Here we aimed to elucidate the impact of long-term SEC-NAFLD-IR on multiple mitochondrial quality control (mQC) mechanisms in the heart and its consequences for cardiac function.

Methods

We studied 36 SEC-NAFLD-IR mice (72-week-old). For mechanistic experiments, we applied palmitate-induced insulin resistant murine HL-1 cells. Cardiac mitochondrial dynamics were measured via quantification of mitochondrial morphology and expression of mitochondrial fusion and fission factors (Opa1, Drp1, Fis1, Mfn 1 & 2). Mitophagy level was evaluated via immunofluorescence and protein expression of key mitophagy-related genes (Parkin, NIX, LC3). Mitochondrial biogenesis and mass were examined via quantitation of PGC-1α expression, mtDNA and citrate synthase activity.

Results

72-week-old SEC-NAFLD-IR mice exhibited 21% (p=0.001) and 32% (p<0.001) higher body weight and heart weight compared with controls. Along with elevated oxidative stress, hepatic lipid accumulation and inflammation, 6h-fasted SEC-NAFLD-IR mice were characterized by increased plasma glucose, insulin and cholesterol. SEC-NAFLD-IR mice displayed a cardiac phenotype with 21% higher left ventricular mass (normalized to body weight, p<0.001) and 6% lower ejection fraction compared to controls (73.5% SEM 0.90 vs 69.4% SEM 1.65, p=0.04). We found several advantageous mQC mechanisms suppressed in aged SEC-NAFLD-IR mice including long form OPA1-mediated mitochondrial fusion, Parkin- and NIX-mediated mitophagy. Likewise, mitochondrial biogenesis was suppressed in the aged insulin-resistant heart, which was connected to a 65% downregulation of PGC-1α1 expression (p=0.01). Interestingly, downregulation of cardiac PGC-1α1 in aged SEC-NAFLD-IR mice coincided with upregulation of PARIS, indicating the crucial participation of the Parkin/PARIS pathway in mQC of the insulin-resistant heart. In addition, induction of insulin resistance in murine HL-1 cardiomyocytes also led to increased mitochondrial fragmentation and decreased PGC-1α1 expression.

Conclusion

This study demonstrated that regulation of mitochondrial network and turnover is hampered by SEC-NAFLD-IR in the hearts of aged mice, which may contribute to hypertrophy and cardiac dysfunction in insulin resistance.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Collaborative Research Centre 1116 (German Research Foundation)
Characterization of cardiac effects of OPA1 protein promotion in transgenic animal model
Authors: Deres L , Ordog K , Horvath O , Bruszt K , Toth S Z , Gallyas F , Toth K , Halmosi R
Published: October 2022

Introduction

Mitochondria forms a dynamic network in cells, which is regulated by the balance between mitochondrial fusion and fission. The inhibition of mitochondrial fission could result in positive effects in acute ischemic/reperfusion injury models, due to prevention of mitochondrial membrane potential fall that goes along with fission processes. However, inhibition of fission in chronic models is disadvantageous because it obstructs the elimination of damaged mitochondrial fragments. OPA1 – in view of the previous results – a possible therapy target, as a fusion promoter and structure stabilizer protein.

Methods

We used transgenic mice in which OMA1 and YME1L cleavage spots of OPA1 were deleted. This resulted in higher representation of L-OPA1 compared to S-OPA1. After genotyping and model validation all animals were examined by echocardiograph and ECG on two occasions, at week 11 and 36. Histology samples were made from hearts, in case of mitochondrial morphology and structure remodelling examination. Cardiomyocytes were isolated from neonatal mice to determine the efficiency of mitochondrial respiration by SeaHorse assay method.

Results

Capillary Western immunoassay proved the presence and higher concentration of OPA1 in the TG animals. Echocardiographic examination showed a significant ejection fraction reduction in TG animals at week 36, but remodelling in histology samples could not be observed. The efficiency of mitochondrial respiration was decreased in TG animals compared to WT animals, according to the results of SeaHorse assay.

Conclusion

OPA1 protein promotion has a negative effect on systolic function during ageing. We confirmed that volume overload and ventricular remodeling did not manifested. The reason behind the loss of pump function might be at least partly the energy deficit due to the mitochondrial respiratory failure and the damage in mitochondrial quality control pathways.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): The research in Hungary was funded by NKFIH within the framework of the project TKP2021-EGA-17.
Arginase 1 in erythrocytes is a critical modulator of cardioprotective signalling by nitric oxide and soluble guanylyl cyclase
Authors: Yang J N , Tratsiakovich Y T , Jiao T J , Mahdi A M , Tengbom J T , Zhou Z Z , Collado A C , Lundberg J L , Pernow J P
Published: October 2022

Background

Arginase is involved in the development of ischemia-reperfusion injury by regulating nitric oxide (NO) bioactivity via competition with NO synthase (NOS) for their common substrate L-arginine. Erythrocytes are known to contain high levels of arginase that may reduce export of cardioprotective NO bioactivity.

Aim

To determine the role of arginase 1 in erythrocytes for cardiac protection against myocardial ischemia-reperfusion injury.

Methods

A tie2 cre-flox mouse model, in which arginase 1 was deleted (Arg 1-KO) in hematopoietic and endothelial cells, was developed. In vivo ischemia-reperfusion was performed in anaesthetized mice by left anterior descending coronary artery ligation (30 min ischemia and 120 min reperfusion). To determine the specific role of erythrocytes, an isolated perfused mouse heart model was applied. Erythrocytes from Arg 1-KO and wild type (WT) mice were given to isolated hearts from WT mice at the onset of global ischemia. After 40 min ischemia, the recovery of left ventricular developed pressure (LVDP) during 60 min reperfusion was recorded as an indicator of cardiac functional recovery.

All animal experiments and procedures were performed according to the guidelines by the U.S National Institutes of Health (NIH publication no 85–23, revised 1996)

Results

Following in vivo ischemia-reperfusion, infarct size was smaller in Arg 1-KO mice than in WT mice (Fig. A). A similar degree of infarct size reduction was obtained by i.v. administration of an arginase inhibitor in WT mice. The cardioprotective effect observed in Arg 1-KO mice was abolished by the NOS inhibitor L-NMMA (Fig. A). In isolated buffer-perfused hearts, there was no difference in the post-ischemic recovery of LVDP between Arg 1-KO and WT hearts. When erythrocytes from Arg 1-KO mice were administrated to isolated WT mouse hearts, the post-ischemic recovery of LVDP was significantly improved compared to hearts given erythrocytes from WT mice. Also, the cardioprotective effect of erythrocytes from Arg 1-KO mice was abolished by pre-incubation of the erythrocytes with the NOS inhibitor L-NAME (Fig. B) or the inhibitor of soluble guanylyl cyclase ODQ (Fig. C).

Conclusion

Arginase 1 in erythrocyte plays an important role in regulating cardioprotection mediated via the NO-soluble guanylyl cyclase pathway.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Swedish Heart and Lung Foundation (20190266),The Swedish Research Council (2020-01372)
Evaluation of the direct protective effects of Canagliflozin on the Isoproterenol-induced cell injury in rat cardiomyocytes
Authors: Murayama Y , Kitasato L , Ishizue N , Suzuki M , Mitani Y , Saito D , Matsuura G , Sato T , Kobayashi S , Nakamura H , Oikawa J , Kishihara J , Fukaya H , Niwano S , Ako J
Published: October 2022

Background

Sodium-glucose cotransporter-2 (SGLT2) inhibitors are agents that act by inhibiting glucose and sodium reabsorption in the proximal renal tubule which promotes urinary glucose excretion. More recently, significant benefit data of SGLT2 inhibitors in patients with heart failure, independent of the presence of type 2 diabetes has been reported. We have previously demonstrated that Canagliflozin (Cana), a SGLT2 inhibitor, reduced the ventricular effective refractory period in isoproterenol (ISP)-induced myocardial injury rat model accompanied with the suppression of reactive oxygen species and the elevation of ketone bodies, suggesting the effect of Cana on electrical cardiac remodeling. The direct effect of Cana to the cardiomyocytes and its underlying molecular mechanism was remained to be clarified. We therefore established an ISP-induced neonatal rat ventricular cardiomyocyte (NRVCM) in vitro model, pretreated with Cana and/or ketone bodies.

Methods

Primary NRVCM were isolated from Wistar rats, were pretreated by Cana with or without βOHB (the most abundant ketone body in circulation), followed by a stimulation of ISP (10μM). Cells without drug or ketone body pretreatment were used as control. We then analyzed its effect on cell viability, apoptosis, and mitochondrial membrane potential using MTT assay, TUNEL assay, and mitochondrial membrane potential assay, respectively. MTT assay was also performed with or without PI3k inhibitor, LY294002. The end-labeling of DNA fragmentation were labelled with FITC, followed by the nuclei counterstain with DAPI and were observed with confocal microscope. The apoptotic index was defined as the percentage of TUNEL positive cells / total nuclei.

Results

Cana rescued the reduction of NRVCM cell viability induced by ISP stimulation for 24 hours which was inhibited by LY294002 compared to cells without pretreatment. Interestingly, pretreatment of βOHB with or without Cana improved also the NRCVM cell viability whereas there was no significant difference between these two conditions or with cells treated with Cana only, suggesting the direct protective effect of Cana. In 48 hours of ISP stimulation, the apoptotic index intends to decrease in Cana and/or βOHB compared to cells without pretreatment (Figure 1). Although the mitochondrial function was maintained in Cana-pretreated cells compared to cells without pretreatment, there was no significant difference in βOHB-pretreated cells.

Conclusions

Cana has a direct protective effect on cardiomyocytes cell viability, apoptosis as well as the mitochondrial function impaired by ISP through the cell survival signaling PI3K/Akt pathway. This brings a new insight to the therapeutic target of cardiovascular disease.

Funding Acknowledgement

Type of funding sources: None.
Metabolic modulation as a common adaptive mechanism in patients with different subtypes of aortic valve stenosis
Authors: Bengel P , Beuthner B E , Topci R , Pietzner M , Hasenfuss G , Toischer K , Schnelle M
Published: October 2022

Background

Aortic valve stenosis (AS) is a rapidly growing global health problem due to aging and population growth. If treatment by aortic valve replacement (AVR) is delayed, this leads to poor recovery of cardiac function and marked increase of mortality. In conditions of AS or heart failure a cardiac remodelling occurs including a change in cardiac substrate utilization. However, it is difficult to determine the stage of AS-induced cardiac remodelling and therefore the reversibility of this changes after AVR. As cardiac metabolism might be therapeutic target for patients not recovering after valve replacement a better understanding of the metabolic remodelling in different AS subtypes is necessary. Metabolomics constitute a potent screening tool for defining changes in global and cardiac-specific metabolism in cardiovascular disease.

Methods/Results

Serum metabolomic profiling for 1293 metabolites was performed in serum samples of 40 AS-patients and 10 healthy controls using Ultrahigh Performance Liquid Chromatography-Tandem Mass Spectroscopy. AS-patients were divided in four groups (10 patients/group) with respect to ejection fraction (EF, normal/reduced) and aortic valve gradient (> or <40 mmHg). Principal component analysis revealed a clear difference of metabolic profiles in AS-patients vs controls. However, less separation between AS-subtypes could be detected. A Random Forest Analysis comparing all AS-patients to healthy controls resulted in a predictive accuracy of 94%. In AS-patients we observed an increase of acyl carnitines compared to control indicating an alteration of myocardial free fatty acid oxidation. Moreover, we detected a higher ketone body concentrations in AS-patients that could serve as an alternative fuel source for the heart. Interestingly, no differences between the AS subgroups could be detected indicating that changes occur independently from EF and AS-gradient. Additionally, several compounds involved in nitrogen balance were increased in AS-patients while numerous amino acids were decreased, possibly also due to alternative energy production. Increased circulating heme catabolites have been associated with heart failure. Here, we found increased heme catabolites only in patients with low EF and high-gradient with unclear significance.

Conclusion

In summary, our study indicates a shift of cardiac substrate utilization in patients with AS from free fatty acid oxidation to alternative substrates like ketone bodies and amino acids. As no differences between AS subtypes were observed, this metabolic remodelling may occur as an adaptive mechanism independent from EF and AS-gradient in patients with severe AS. Since our study was conducted by an unspecific approach with a small sample size, further investigation is necessary for a better understanding of the specific myocardial metabolic changes in AS patients.

Funding Acknowledgement

Type of funding sources: None.
Association of heart failure and liver T1 mapping in cardiac magnetic resonance imaging
Authors: Bartkowiak J , Peters A , Seitz R , Bernhard B , Praz F , Graeni C , Brugger N , Huber A
Published: October 2022

Background

Heart failure culminates in liver congestion. As the liver can be assessed by cardiac magnetic resonance T1 mapping sequences, it represents a promising imaging biomarker for heart failure.

Objectives

To evaluate the association between heart failure and magnetic resonance liver T1 mapping, as a non-invasive imaging surrogate of liver congestion.

Methods

Patients with cardiac magnetic resonance including T1 mapping sequences on a single 1.5T scanner were consecutively included between 01/2017 and 12/2019. Liver T1 was measured in the left lobe, right lobe and caudate lobe on short axis view and in the liver dome on four chamber view. Echocardiographic and laboratory parameters were analyzed within 90 days of the cardiac magnetic resonance exam. Left ventricular filling pressures were assessed according to the European Association of Cardiovascular Imaging guidelines [1]. Liver T1 and echocardiographic parameters were compared between patients with and without elevated NT-proBNP levels (>125 pg/ml) using a Mann-Whitney U test. A multivariate logistic regression model was used to correct for age, sex, body mass index, left ventricular ejection fraction and the presence of atrial fibrillation.

Results

A total of 397 patients were included (median age 56, 127 females), of whom 138 patients (35%) presented with elevated NT-proBNP levels. Patients with elevated NT-proBNP levels had a larger indexed end-diastolic left ventricular volume (92 vs. 81 ml/m2, p<0.001), lower left ventricular ejection fraction (60 vs. 50%, p<0.001) and a higher E/E' ratio (11 vs. 8, p<0.001). Liver T1 was higher in patients with elevated NT-proBNP in the right liver lobe (670 vs. 596 ms, p<0.001) and the caudate lobe (664 vs. 598 ms, p<0.001), but not in the left liver lobe (571 vs. 568 ms, p=0.068) and in the liver dome (590 vs. 560 ms, p=0.1). Echocardiographic evaluation showed similar results with significant difference in T1 times between patients with elevated and non-elevated left ventricular filling pressures in caudate and right liver lobe. Liver T1 retained its predictive value when corrected for age, left ventricular ejection fraction and the presence of atrial fibrillation, when measured in the caudate lobe (adjusted odds ratio 1.013, 95% confidence interval 1.004–1.023, p=0.005) and in the right lobe (adjusted odds ratio 1.012, 95% confidence interval 1.003–1.021, p=0.009).

Conclusions

Elevated liver T1 in cardiac magnetic resonance imaging is associated with heart failure and represents an independent non-invasive imaging surrogate for liver congestion.

Funding Acknowledgement

Type of funding sources: None.