bluuebunny/crossref_metadata_2025 huggingface dataset:
Implementation of digital patient decision support tools for Atrial Fibrillation treatment: systematic review
Authors: Laranjo L , Zeng A , O'hagan E , Chow C
Published: October 2024

Background/ Introduction

Treating atrial fibrillation (AF) involves complex decisions. Digital patient decision-support tools can facilitate shared decision making by significantly reducing decisional conflict and improving patient knowledge [1,2]. Yet, implementation in clinical practice is lagging [3].

Purpose

To systematically review trials of digital patient decision-support tools for AF treatment decisions, focusing on factors influencing their implementation in clinical practice.

Methods

We conducted a systematic review following Cochrane methods. EMBASE, MEDLINE and Scopus were searched from 2005 to 2023. Eligible randomised controlled trials and quasi-experimental trials that evaluated digital patient decision-support tools for AF treatment decisions were included. Two independent reviewers screened title and abstract, extracted data and assessed risk of bias. The implementation outcomes included a description of when and how the tool was used, as well as its characteristics and user satisfaction.

Results

Thirteen articles reporting on eleven studies (5 RCTs and 6 quasi-experimental trials) met the inclusion criteria (2,714 participants; mean age 71±4.2 years; 26% women; 92% with non-valvular AF, remaining not reported). Risk of bias was low for 2 studies, moderate for one and high for seven studies. All tools (n=11) focused on anticoagulation choice (1: warfarin vs no warfarin; 1: aspirin vs warfarin; 7: Direct Oral Anticoagulants (DOAC) vs antiplatelet or warfarin; 2: unspecified choice). The tools were used either pre-visit (at home or in the waiting room) or during the consultation (n=5). Tools were delivered using a mobile application (n=4), web-based application (n=5), or a desktop (n=2). Of the eleven tools, 2 could automatically calculate individualized stroke risk using data from electronic health records. Most articles reported favourable user feedback regarding use of the digital patient decision-support tools, such as high perceived usefulness, user-friendliness, and overall satisfaction. No significant difference was found in encounter times between intervention and control arms (2 RCTs). Four tools were publicly available and 3 were implemented in healthcare delivery beyond research.

Conclusion

Despite demonstrated efficacy in reducing decisional conflict and improving patient knowledge, as well as positive clinician and patient experience, only 3 tools were implemented in clinical practice beyond their trial. Future tools could better leverage digital capabilities to integrate with Electronic Health Records, automate stroke and bleeding risk calculations, and personalise content based on patient values and preferences. Additional robust trials and implementation studies are warranted to understand barriers and enablers to the use of these tools.
Differences in treatment and outcome of patients with ST- Elevation Myocardial Infarction (STEMI) and Non-STEMI in Germany
Authors: Lange S A , Engelbertz C M , Feld J , Makowski L , Karanatsios G , Fischer A J , Guenster C , Droege P , Ruhnke T , Gerss J , Reinecke H , Koeppe J
Published: October 2024

Background

ST-elevation myocardial infarction (STEMI) and non-STEMI (NSTEMI) are the main diagnoses of acute coronary syndrome (ACS). Although both types of infarction are classed as ACS, the treatment and overall survival rate are different.

Methods

Health claims data (≈26 million members) were screened for patients with STEMI and NSTEMI from 01/2010 to 12/2018. Patient demographics, hospitalization details, adherence to guideline-directed drug therapy, and survival were assessed.

Results

The total cohort of acute myocardial infarctions comprised 544,529 patients (mean age 74 (IQR 62 - 82), one third of whom were hospitalized with a STEMI. Patients with STEMI were more likely to be in a life-threatening situation and had higher in-hospital, 30- and 60-day mortality, but better long-term survival. Major adverse cardiac and cerebrovascular events (MACCE), infarct recurrence, chronic kidney disease, peripheral arterial disease, heart failure and cerebrovascular disease were more common in patients with NSTEMI. STEMI-patients received coronary angiography and percutaneous coronary intervention more frequently. Although there was a clear correlation between guideline-compliant therapy and overall survival, adherence to guideline-compliant therapy decreased over time, especially in NSTEMI patients.

Conclusion

In ACS patients, there are clear differences between STEMI and NSTEMI patients in terms of short- and long-term survival. Guideline-based therapy improved long-term survival in both, but more significantly in STEMI patients.
Advanced waveform analysis of the electrocardiogram signals using complementary signal processing techniques to investigate the response to a QTc prolonging drug vs control
Authors: Rickard J , Nandi M , Djumanov D , Mejia E , Sadsad T J , Taubel J , Lorch U , Serna Pascual M
Published: October 2024

Background

Thorough QTc (TQT) studies using Electrocardiogram (ECG) data, are a well-established method for testing the pro-arrhythmic propensity of drugs performed during safety studies as part of drug development. ECG analysis is currently reduced to simplified biomarkers, such as rate, intervals and amplitudes. However, ECG waveforms are complex and generally sampled with high fidelity (125-1000 Hz). Our novel mathematical method, Symmetric Projection Attractor Reconstruction (SPAR) analyses the morphology and variability of such waveforms, using every data point to generate a new, faithful 2D waveform representation termed an ‘attractor’.

Moxifloxacin is a reversible blocker of the rapid component of the delayed rectifier, potassium current of the cardiac IKr potassium channel and has been shown to cause a mean increase of the QTc interval of 10–14 ms after an oral single dose of 400 mg. Separately, studies have shown that meals can alter QT interval as well as altering the pharmacokinetic profile of moxifloxacin itself with gender and ethnicity impacting individual responses. In-depth knowledge of these physiological factors could support safer medicines development and clinical use.

Purpose

This project investigated the feasibility of SPAR analysis of ECG signals to detect drug induced changes which a higher degree of sensitivity, to support safety evaluation during medicines development.

Methods

High resolution triplicate 12 lead ECG time-series data from a Phase one study of healthy human volunteers cross over of placebo, moxifloxacin or moxifloxacin + food was retrospectively analysed using SPAR. Using a bespoke software tool was used to perform SPAR analyses to transform ECG time-series into corresponding attractors. Corresponding single point measurements were previously obtained as part of the original Phase one study.

Results

Initial evaluation of attractors revealed high inter-individual variation, consistent with previous SPAR ECG analysis. Nevertheless, we identified changes in subjects receiving Moxifloxacin (six hour time point) when compared to those receiving placebo control. These changes were not as evident in previously obtained QT intervals.

Conclusion

This pilot study illustrates that SPAR is highlighting changes on the ECG that are less obvious from QT data alone. Further evaluation of the whole dataset to identify generalisable SPAR features, and their comparison with existing markers is now necessary. The individualised nature of ECGs and corresponding attractors indicates the method may have highest utility in personalised medicine, evaluating each individual’s change and hence individual risk to drug induced arrhythmia.Visualisations of SPAR analysis of ECGs
Substantial morbidity and mortality due to cardiovascular diseases in hospitalized vaccinated and un-vaccinated patients with COVID-19 from 16 countries: the WHF COVID-19 Long-term study
Authors: Sliwa Hahnle K , Raspail L , Singh K , Nikhare K , Akter S , Talukder S H , Kato T , Bertagnolio S , Rylance J , Banerjee A , Narula J , Pineiro D , Perel P , Prabhakaran D
Published: October 2024

Background

Long-term adverse consequences of the COVID-19 affect many organ systems, and this requires the identification and appropriate care of diverse symptoms.

Purpose

The World Heart Federation (WHF) international study describes the burden of clinical sequelae of COVID-19 up to 1 year after hospitalization, including patients from low- middle-and high-income countries.

Methods

We prospectively recruited patients hospitalized due to COVID-19 from 16 countries between January 2022 and June 2023. Patients were followed up at 1, 3, 6, and 9-12 months after hospital discharge. A standardized questionnaire administered by telephone collected data on long COVID symptoms, quality of life using the EuroQol 5 Dimension scale (EQ-5D), and disease outcomes including new onset diabetes and hypertension, major adverse cardiovascular events (MACE), and mortality. We report a descriptive analysis including demographic characteristics and outcomes up to one year after initial hospitalization.

Results

Of 2504 patients, the majority were Asian (78%), and male (56%). Mean age was 59.2 years (SD 19.9). Low- and lower-middle-income country participants constituted 65% of the cohort, with upper middle-income and high-income representing 20% and 15%, respectively. Follow-up rate was complete for 86%. 55% had received at least two doses of COVID-19 vaccination. At 1 month, 63% reported at least one persistent symptom, which decreased to 28% at 9-12 months. Fatigue was reported by 45% at 1-month and 17% at final follow-up. Anxiety occurred in 20% and 9% at these respective timepoints, and breathlessness in 12% and 6%. At 9-12 months, moderate to severe impairment of usual activities as measured by EQ-5D occurred in 19%, anxiety/depression in 10%, and mobility problems in 10%.

The most frequent post-discharge new-onset illnesses were pulmonary embolism (7%), kidney problems (4%), and hypertension (3%). In-hospital mortality was 4% (n=102), and a further 12% (265 patients) died by one-year. The most common cause was sudden cardiac death (59%), respiratory disease including pulmonary embolism (13%), and stroke (6%).

Conclusions

We observed a significant burden of post-COVID-19 complications with one fifth of patients with persistent difficulties in usual activities at one year. This underscores the urgent need to understand the underlying mechanisms for organ damage and death, and for targeted preventive strategies and proactive management approaches to reduce them.
Effects of deferment of clinic visit on cardiovascular outcomes during COVID-19 outbreak: a prospective cohort study
Authors: Lai A , Hui K H , Yan B , Tan G M
Published: October 2024

Background

Current guidelines recommend 3-6 months interval outpatient follow-up for patients with cardiovascular (CV) diseases and risk factors such as hypertension, diabetes mellitus (DM) and dyslipidemia. The impact of longer follow-up intervals is unclear. From 2020 to 2022, due to the infection control measures for COVID-19 pandemic, many patients voluntarily deferred their scheduled clinic visits. This provided us with an opportunity to study the impact of prolonged visit intervals on management CV risk factors.

Purpose

We aimed to investigate the impact of prolonged clinic visit intervals on CV outcomes and CV risk factor management among patients with CV diseases.

Methods

Patients with at least 1 CV risk factor (DM, hypertension, dyslipidemia, or a history of CV disease) were recruited from cardiology outpatient clinics from a tertiary teaching hospital from 2020-2022. Patients who opted to defer their appointment (Deferred group) were compared to those who attended their scheduled appointment (Normal group). The primary outcomes were composite major adverse cardiovascular events (MACE) of myocardial infarction, stroke, or CV-related death. The secondary outcomes were any unscheduled hospitalizations, suboptimal DM control (haemoglobin A1C >7%) or hyperlipidemia (LDL > 1.4 mmol/L).

Results

Out of the 455 patients recruited from outpatient clinics, 162 patients (35.6%) opted to defer their scheduled clinic visit (mean age 64.7 ± 12, 37.7% female), and 293 patients (mean age 64.5 ± 10, 36.2% female) continued to attend their appointments. The mean appointment interval was 226 days for the normal group and 582 days for the deferred group (p< 0.001). There was no significant difference in the primary outcome of MACE between the ‘Normal’ group and the ‘Deferred’ group (2.5% vs 0.6%, p=NS). The number of patients with suboptimal DM control (11.4% vs 21.9%, p = 0.029) was higher in the deferred group, whereas suboptimal hyperlipidemia (73.1% vs 77.1%, p=NS) was not statistically different. There were a total of 27 of unscheduled hospitalizations, among which the majority was for CV-related events (63.0%). Patients in the ‘Deferred’ group had higher rates of unscheduled hospitalization (12.3% vs 2.4%, p < 0.001) and higher rate of CV-related hospitalization compared to the ‘Normal’ group (6.2% vs 2.4%, p=0.041).

Conclusion

Our prospective data demonstrates that a prolonged clinic visit interval of more than 365 days was not associated with significant increase in adverse CV event or worsening of lipid control. However, prolonged clinic visit interval was associated with worse DM control and more frequent unscheduled hospitalization. More frequent medical contact might allow timely management of medical emergency at the outpatient setting and contribute to the lower rate of hospitalization in the routine follow-up group.
Embedding a text message recall system to increase the uptake of cardiovascular screening in Australian general practice. Results of the Text to Detect randomised controlled trial
Authors: Raffoul N , Brims K , Knight J , Nelson A , Asham A , Bonner C
Published: October 2024

Background

Australian guidelines recommend cardiovascular disease (CVD) risk screening for adults aged 45-74 years, but less than one in three have blood pressure and cholesterol recorded within their general practitioner (GP) records. Medicare subsidised ‘Heart Health Checks’ were introduced in primary care in 2019, however uptake has been suboptimal.

Purpose

The aims of this study were to; 1) implement a text mediated Heart Health Check recall program within general practice at scale, 2) determine whether uptake can be increased with nudge reminder text messages and 3) evaluate the impact on risk factor measurement and medication prescription.

Methods

Australian general practices were invited via advertisement and mailing list. Medical record software identified patients eligible for a Heart Health Check. Practices were randomised to one of three arms: 1) standard SMS: 1 SMS inviting patients to see their GP for a Heart Health Check, 2) nudge reminder: standard SMS + nudge reminder two weeks later, 3) control: no SMS. Aggregate, deidentified, practice-level data was extracted at baseline and 3-months. The primary outcome was the proportion of Heart Health Checks delivered at a practice level. Secondary outcomes included updated CVD risk factor assessment and new medication prescriptions. Analyses used ANOVA and Tukey's HSD.

Results

Between 2022 and 2023, 206 general practices participated, each with 560 median eligible patients (IQR:297-909). A total of 70,679 recall text messages and 34,406 nudge reminder messages were sent. Heart Health Check uptake was 11 and 16 times higher in the standard and nudge arms (respectively) compared to control (0.4 vs 4.5 vs 6.3 per 100 patients, p<0.001), with a 40% statistically significant increase (p=0.02) for 2 SMS vs 1 SMS. Updated cholesterol values were 31.6 and 60.2% higher in standard and nudge arms (respectively) compared to control (13.7 vs 16.8 vs 17.4 per 100 patients, p=0.02). Both active arms were statistically significantly different from control (standard p=0.047, nudge p=<0.001). Updated blood pressure was 23.0 and 26.8% higher in the standard and nudge arms (respectively) compared to control (13.7 vs 16.8 vs 17.4 per 100 participants), however only the nudge arm was statistically significantly different (p=0.38). New medication prescription (lipid or blood pressure-lowering) was 36.8% higher in the nudge arm compared to control (32.1 vs 43.9 patients per practice, p=0.03).

Conclusions

This study demonstrates the effectiveness of text mediated recall of eligible patients to increase the uptake of cardiovascular risk screening in Australian general practice. The findings will inform the implementation of new Australian guidelines and policy reform.
Analysis of safety and outcome of use of NOAC in intracardiac thrombi over warfarin
Authors: Al-Assaf O , Baaj B , Abumuaileq M , Roqia S , Elberry M , Musa A
Published: October 2024

Introduction

Intracardiac clots occur in 15- 25% of patients post myocardial infarction and in patient with atrial fibrillation. It holds poor outcome if not treated with anticoagulation. Warfarin remains the drug of choice in such patients, however recently according to the newly published data, the European Society of Cardiology (ESC) has recommended non-vitamin K antagonist anticoagulant (NOAC) for intracardiac clots as a class 2A recommendation. There is no documented data in the region of the gulf regarding the use of NOAC in intracardiac clots.

Aim

We aim in this study to evaluate the use of NOAC in the treatment of intracardiac clots over warfarin, by studying the effectiveness, safety and associated complications.

Methodology

A retrospective cohort study from April 2017 to December 2023 was conducted of patient’s above 18 years old who have a documented intracardiac clot on echocardiography. The patient were grouped into patients discharged on NOAC and those discharged on warfarin. The participants were studied for resolution of clot and development of complication; death, bleeding and thrombosis.

Results

A total of 253 patients fulfilled the inclusion criteria. Out of which 45 ( 18%) patients were discharged on NOAC and 208 (82%) on warfarin. The two groups had similar demographics with equally mean age of 71 years old , 89% being males, 38% hypertensive and most common clot in the left ventricle in both groups. From those patients with documented follow up ( NOAC 45% average of 8 months, Warfarin 62% average of 7 months); 48% in the NOAC group had a documented resolution of the clot while 44% in the warfarin group had a documented resolution of the intracardiac clot.(p value of 0.7) The median resolution time in the NOAC group was 4 months while in the warfarin group 3.5 months. Bleeding occurred in 19% and mortality rate was 5% in NOAC group, while in the warfarin group 10% developed bleeding and mortality rate was 6%.

Conclusion

Our data pointed out the safety of NOAC as a reasonable alternative to warfarin inpatient with intracardiac clots emphasizing the ESC recommendation in this regards. We recommend a randomized studies to prove the superiority of NOAC as anticoagulation of choice in intracardiac thrombi.
Cost differences between oral anticoagulation therapies in atrial fibrillation patients
Authors: Lehtonen O , Halminen O , Airaksinen K E J , Haukka J , Putaala J , Mustonen P , Teppo K , Lehto M , Linna M
Published: October 2024

Background

Direct oral anticoagulants (DOACs) have largely replaced warfarin as the primary choice of oral anticoagulation (OAC) in atrial fibrillation (AF) patients. This study uses a nationwide registry data set to compare the health and social care costs of AF patients using different OAC therapies. We studied how these costs were distributed among different care services in the year following AF onset and how the costs develop in time before and after AF diagnosis.

Methods

This study is a part of the Finnish AntiCoagulation in Atrial Fibrillation (FinACAF) research project, which includes data on patients with AF, combining registry data on primary and secondary care services as well as social services, drug purchases and laboratory data. We included all new-onset AF patients from 2011 to 2017 in Finland with an indication for OAC treatment. Patients were divided based on their first OAC purchase. Time in therapeutic range (TTR) values were assessed for warfarin patients, and they were divided into quartiles based on their TTR value.

Standardized costs were determined for different health and social care contacts, accounting for hospital care, primary and ambulatory care, and long-term care. Drug costs were acquired from the Reimbursement for Prescription Medicines registry.

Results

A total of 130,745 patients (66,610 on warfarin, 32,996 on DOACs) were included. First-year total costs after onset of AF were €10,412 for rivaroxaban (n=13,320), €12,631 for apixaban (n=11,886), €10,706 for dabigatran (n=7,514) and €10,689 for edoxaban (n=366). Costs of care clustered near the diagnosis of AF (Figure 1). Costs for warfarin patients increased inversely with TTR, ranging from €10,945 in the highest TTR quartile (TTR over 82%) to €21,387 in the lowest (TTR under 57%). Average first-year costs for warfarin patients were €15,689, higher than DOAC patients by €3,058-€5,277 (Figure 2). Patients without any OAC had the highest first-year costs, €17,898. Patients with high risk of stroke had higher total costs both in patients using DOACS (€7,271 for patients with a CHA2DS2VA score of 1 vs €11,947 for patients with CHA2DS2VA 2+) and warfarin (€9,933 for CHA2DS2VA 1 vs €16,354 for CHA2DS2VA 2+). Drug costs averaged €1,541 for rivaroxaban, €1,659 for apixaban, €1,495 for dabigatran and €1,540 for edoxaban, and €986 warfarin users.

Hospital care was the largest cost driver with 64% of total costs across the whole cohort, followed by primary care (19%), drug purchases (7%), social service costs (6%) and reimbursements for travel and private care (4%).

Conclusions

DOACs were superior to warfarin in a broad range of social and healthcare cost measures despite higher drug expenses. Patients on warfarin with low TTR and patients without any OAC had the highest cost of care.
Sub-Saharan Africa's contribution to clinical trials in international acute coronary syndromes and heart failure guidelines
Authors: Hudson J , Sanga L , Jobe M , Etyang A , Perel P , Ogola E , Shah A S V
Published: October 2024

Introduction

There is a growing burden of acute coronary syndrome (ACS) and heart failure (HF) in sub-Saharan Africa (SSA), yet outcomes remain poor compared to high-income countries (HICs). Global clinical guidelines are pivotal to the delivery of evidence based cardiovascular care, however their applicability to populations in SSA remains unclear.

Purpose

To evaluate the extent to which populations from SSA contribute to pharmacotherapeutic randomised clinical trials informing international ACS and HF clinical guidelines.

Methods

We extracted details on pharmacotherapeutic randomised control trials (RCTs) contributing to Class I or II guideline recommendations from the 2023 European Society of Cardiology (ESC) guidelines for ACS and the 2021 ESC guidelines for HF. Data on RCTs contributing to these guidelines were extracted from the ClinicalTrials.gov or published articles. We analysed the proportion of RCTs which had a contribution from countries in each World Bank income group. Then we specifically assessed the contribution of SSA countries to clinical trials and analysed temporal trends.

Results

Of 119 RCTs from the ESC HF guidelines and the 343 pharmacotherapy RCTs from the ESC ASC guidelines 75.9% were exclusively conducted in high-income countries, 22.2% of the trials included at least one site from a middle-income country and none included sites from a low-income country (figure 1). The global distribution of HF (figure 2a) and ACS (figure 2b) pharmacotherapy guidelines is demonstrated in figure 2. The only country represented from SSA was South Africa which is an upper middle-income country. A site from South Africa was included in 17 (14.2%) HF RCTs and 28 (8.2%) ACS RCTs. There has been a significant increase in the proportion HF RCTs conducted in SSA, increasing from 2.6% between 1990 and 1999 to 50% since 2020 (OR 28.8, 95% CI 2.6 – 983.4, p-value for trend< 0.0001). For ACS RCTs, the proportion of trials conducted in SSA increased from 1.8% pre 1990 to 23.4% during 2000-2009 (OR 15.9, 95% CI 4.2 - 112.9, p value for trend = 0.003) then declined to 11.3% from 2010-2019.

Conclusions

There is a marked under-representation of SSA countries in ACS and HF pharmacotherapy RCTs, despite the region's escalating cardiovascular disease burden. South Africa is the sole contributor from the region, with all other SSA countries absent. This finding could potentially affect the applicability and generalisability of global guidelines to populations in SSA with distinct clinical presentations and healthcare challenges.Figure 1 Figure 2
Impact of glucose fluctuation on the paracrine secretome profile of human epicardial adipocyte
Authors: Kondo H , Takano M , Takahashi N
Published: October 2024

Background

Glucose fluctuations (GF) is known to be the significant factor related to poor cardiovascular outcome in the diabetic patients. We investigated the potential impact of GF on paracrine effect of human epicardial adipocyte on cardiomyocyte.

Methods

Human EAT biopsies obtained during surgery and isolated preadipocyte/adipocytes were used to evaluate the direct impact of GF on the adipocytes. Matured adipocytes were exposed to the media containing normal glucose (100 mg/dl, NG), high glucose (300 mg/dl, HG), or high-low glucose (75-300 mg/dl, GF) for 1 week. Transcriptomic profiling of the cultured matured adipocyte was performed using microarray analysis. The impact of GF on the paracrine effect of adipocyte was evaluated using a co-culture with human iPS-derived atrial cardiomyocytes and the adipocytes. Clinical association study verified the validity of the findings.

Results

GF for 1 week altered the expression of 595 differentially expressed genes (up-regulated or down-regulated) with an effect size of >50% or `−50% and a significant statistical difference (P < 0.05) in human epicardial adipocytes, while the continuous HG for 1 week altered the expression of only 182 differentially expressed genes. Of the genes affected by GF, top 3 most affected genes included IL1β, IL33, IL8. Regarding the other major pro-inflammatory cytokines, IL1α, CCL2 and IL6 were also significantly increased in the adipocyte treated with GF, however these were not increased in the adipocyte treated with HG. Co-culture of human iPS cell-derived atrial cardiomyocytes and adipocytes treated with NG, HG and GF revealed that GF-treated adipocyte strikingly increased oxidative stress in the cardiomyocyte through the paracrine effect. In the real-world clinical association study, IL1β mRNA expression in human epicardial adipose tissue showed significant positive correlation with the severity of GF during hospitalization and oxidative stress in the left atrial myocardium.

Conclusions

GF adversely affect the paracrine secretome profile of human epicardial adipocyte. IL1β may be a critical epicardial adipocyte-derived adipokine that is enhanced by GF.
Cardiomyocyte proliferation is promoted by intracellular Gas6-mediated Yap activity during neonatal heart regeneration
Authors: Liu Y , Zhou W , Xu Y , Xiao Y , Xie W , Ma G , Fan Y
Published: October 2024

Purpose

The adult mammalian heart has limited regenerative capacity after injury, mostly attributable to postnatal cardiomyocyte (CM) cell cycle arrest. The key to unlocking the regenerative potential of the adult hearts may lie within the developmental transitions occurring during neonatal life. Gas6, a secretory protein, stimulates the proliferation of various type cells through binding to TAM receptor family, such as endothelial progenitor cells, tumor cells, and hair follicle stem-cell. However, no study to date has studied the role of Gas6 during the proliferation of CMs. Herein, our study uncovers that Gas6 is transiently expressed during early postnatal heart and regenerative heart, and functions through intracellular pathway by regulating Yap activity to promote CM proliferation.

Methods

CM isolation was conducted to assess the change of Gas6 expression in both postnatal development and regenerated stages using the CM-specific Tdtomato mice. Cardiac deletion of Gas6 gene mice was used to evaluate the impaired heart regeneration. CM-specific Gas6 overexpression mice were generated using adeno-associated virus system to evaluate Gas6 pro-proliferate and protect effect after ischemic injury. Secreted signal peptide truncation (ΔSP-Gas6) and predicted functional region truncation (ΔCC-Gas6) were generated to identify the intracellular mechanism of Gas6 via Sav1/p-mst1/p-lats1/ p-yap axis.

Results

We found that Gas6 expression is enriched in CM4 and the expression profile correlates with the expression of the CM4 marker Acta2, as well as cell-cycle genes Mki67 and Aurora B, in individual CM. Gas6 was highly expressed in the neonatal heart and continued to increase during the neonatal heart regenerative process, but was nearly absent in the adult heart under physiological and ischemia conditions. CM-specific Gas6 deletion resulted in significantly reduced CM proliferation rate and increased CM size in P0 hearts, and congestive heart failure in P28 hearts. Conversely, sustained CM-specific overexpression of Gas6 in postnatal hearts increased CM division, elevated CM numbers, and reduced CM size; and reduced infarct scar area and enhanced cardiac function after ischemia injury. Pre-overexpression of Gas6 in adult CMs protected adult cardiac function against ischemia injury, indicated by the activation of mitosis, angiogenesis and reduced oxidative phosphorylation. In primary neonatal CMs, both Gas6 and ΔSP-Gas6promoted CM proliferation with sarcomere disassembly. Mechanistically, Gas6 interacted with Sav1to inhibit Mst1recruitment and Mst1/Lats1/Yap phosphorylation cascade, therefore, promoted Yap translocation into nucleus.

Conclusions

We demonstrate that Gas6 is an important intrinsic regulator of neonatal heart regeneration, which acts as a promoter of Yap transcriptional activity to enhance CM proliferation. Supplementing Gas6 in the adult heart represents a potential therapeutic approach for cardiac repair.
A Genome-Wide Association Study (GWAS) of Takotsubo syndrome
Authors: Hakansson H F K , Tornvall P
Published: October 2024

Background

Takotsubo syndrome (TS) is an acute cardiac condition of unknown etiology characterized by transient regional systolic dysfunction of the left and/or right ventricle. Several studies have suggested the importance of genetics; however, studies are limited and have presented conflicting results.

Purpose

To identify potential genetic risk variants associated with TS.

Methods

A case-control GWAS in three steps; I) A discovery study with Swedish takotsubo cases (n=260) and age- and sex-matched controls without heart disease from the UK Biobank (n=3034), II) A replication study of Swedish takotsubo cases (n=250) and sex- and age-matched Swedish controls without myocardial infarction from the Swedish coronary angiography and angioplasty register (n=229), III) A Meta-analysis of study I-II with extended controls from the UK-biobank (n=5161). Genotyping was performed using the Axiom® UK Biobank Genotyping Array including 820 000 single nucleotide polymorphisms (SNPs). After applying filters and QC control around 480 000 SNPs remained with a Bonferroni corrected p-value 1*10^-7, minor allele frequency (MAF 1.5-2%), Hardy-Weinberg (HWE) 10^-6. QC, filtering and analysis were performed in PLINK 1.9 and R v 4.0.

Results

In the discovery (I) 1490 SNP:s fulfilled a significance level of <10^-4, of which 36 SNP:s replicated (II) with a significance level of <10^-2, 11 reached a significance level of 10^-7 in the meta-analysis (III). One of the 36 SNP:s, rs1614887, replicated (II) with a significance level of 10^-3. This SNP is an intron variant in the butyrophilin subfamily 2 member A2 gene, a glycoprotein receptor involved in lipid, fatty-acid and sterol metabolism highly expressed in the heart. Of the 11 SNP:s with a significance level of 10^-7 in the meta-analysis (III) several risk variants were associated with psoriasis.

Conclusions

This is the largest GWAS of takotsubo syndrome performed so far, identifying one candidate gene and several potential risk variants. Further research of genetic risk variants in TS is warranted.
Empagliflozin treatment rescues abnormally reduced Na+ currents in ventricular cardiomyocytes from dystrophin-deficient mdx mice
Authors: Sauer J , Marksteiner J , Lilliu E , Hackl B , Todt H , Kubista H , Dostal C , Podesser B , Kiss A , Koenig X , Hilber K
Published: October 2024

Background

Cardiac arrhythmias represent a major cause of death in Duchenne muscular dystrophy (DMD), a devastating muscle disease caused by dystrophin deficiency. An important source for arrhythmia vulnerability in DMD patients is impaired ventricular impulse conduction, which predisposes for ventricular asynchrony, and the development of reentrant circuits. Using the dystrophin-deficient mdx mouse model for DMD, we and others previously reported that the absence of dystrophin results in a significant peak Na+ current (INa) loss both in ventricular cardiomyocytes of the working myocardium, and in Purkinje fibers, ventricular myocytes specialized for rapid electrical impulse conduction. This finding provided a mechanistic explanation for ventricular conduction defects and concomitant arrhythmias in the dystrophic heart.

Purpose

In the present study, we tested the hypothesis that empagliflozin (EMPA), an inhibitor of sodium/glucose cotransporter 2 in clinical use to treat type II diabetes and nondiabetic heart failure, rescues the loss of peak INa in dystrophin-deficient ventricular cardiomyocytes.

Methods

In a first set of experiments, we treated a cohort of mdx mice with 15 mg/kg body weight/day EMPA via the drinking water. After 4 weeks of treatment, ventricular cardiomyocytes were isolated from these mice, as well as from untreated wild-type and mdx control mice, via Langendorff heart perfusion and enzymatic digestion. Peak INa was measured using the whole cell patch clamp technique. In a second experimental approach, peak INa was compared after a 24 hour exposure of isolated mdx ventricular cardiomyocytes with 1 µM EMPA, 10 µM of the Na+-H+ exchanger 1 inhibitor cariporide, or 10 µM cariporide in combination with 1 µM EMPA. In a third set of experiments, we superfused freshly isolated mdx ventricular cardiomyocytes with 1 or 10 µM EMPA in order to examine the acute action of the drug on peak INa.

Results

Consistent with the literature, we found peak INa of mdx ventricular cardiomyocytes to be substantially decreased compared to wild-type. Peak INa of ventricular cardiomyocytes derived from mdx mice, which had received EMPA for 4 weeks, was restored to wild-type level. Moreover, incubation of isolated mdx ventricular cardiomyocytes with EMPA for 24 hours significantly increased their peak INa. This effect did not depend on Na+-H+ exchanger 1 inhibition by the drug. The voltage dependencies of INa activation and fast inactivation were neither modified by long-term treatment nor incubation with EMPA. Finally, acute application of EMPA did not influence peak INa.

Conclusion

Our findings indicate that EMPA treatment can correct abnormally reduced peak INa of dystrophin-deficient ventricular cardiomyocytes. Long-term EMPA administration may diminish arrhythmia vulnerability in DMD patients.
Vitamin D in cardiac fibroblasts: new evidence for a TRP-mediated non-genomic pathway
Authors: Saliba Y S , Nakhl S N , Chedid El Helou M C H , Fares N
Published: October 2024

Background/Introduction

Vitamin D’s (VD) role transcends phosphocalcic metabolism to affect different systems, notably the cardiovascular system in health and diseases. Beyond its genomic effect, VD act through non-genomic calcium (Ca2+) signaling pathways, hinting at a broader spectrum of physiological impacts. Despite the established interactions with cardiomyocytes via the Vitamin D Receptor (VDR), little is known about VD and cardiac fibroblast, a pivotal cell player in cardiac function and disease.

Purpose

This research aims to reveal Vitamin D's role in modulating cardiac fibroblast function through Transient Receptor Potential (TRP) channels.

Methods

Utilizing primary cardiac fibroblasts from human and rats, our investigation focused on intracellular calcium signaling. Through Ca2+ imaging techniques combined to synthetic fluorescent VD analogue, we explored Vitamin D's behavior within the cell. The study further employed biochemical assays to elucidate the interaction between VDR on the cell membrane and TRP channels signaling, providing a detailed map of the cellular choreography orchestrated by VD within cardiac fibroblasts. In addition, in vitro and ex vivo heart perfusion experiments were incorporated to assess cardiac cGMP production in response to VD.

Results

Our findings reveal a unique pathway wherein VD induces Ca2+ oscillations in human and rat cardiac fibroblasts specifically through the TRPC3 channel, sidelining other calcium sources. This process is regulated by the interaction between TRPC3 and the membrane-bound VDR, harmonizing with phospholipase C signaling to a crescendo of cGMP production in cardiac fibroblasts, and across the entire heart. This was associated with less pro-fibrotic potential of cardiac fibroblasts.

Conclusion

This study provides the first evidence of a TRP-mediated, VD non-genomic pathway within human and rat cardiac fibroblasts. Our findings herald a promising horizon for investigating vitamin D’s antifibrotic potential in heart disease.
Characterization of knock-in zebrafish models with a novel SLC4A3 variant identified in a short QT syndrome family
Authors: Zhu M , Wang Q , Horie M , Ogawa M , Kikuchi K , Ohno S
Published: October 2024

Background

Short QT syndrome (SQTS) is one of the lethal inherited arrhythmia syndromes leading to ventricular fibrillation (VF) and cardiac death. It is mainly caused by pathogenic variants in ion channel related genes, especially KCNH2 which produces IKr. Recently, SLC4A3 encoding a membrane-localized anion exchanger 3 (AE3) that regulates intracellular pH (pHi), has been reported as a causative gene for SQTS. However, the molecular mechanism of SLC4A3 variants which cause SQTS remains unclear.

Purpose

Functional characterization of a novel SLC4A3 variant identified in a SQTS family.

Methods

We performed target gene and whole exome sequencing to detect pathogenic variants in a family with SQTS. Patch-clamp analyses were performed to determine the electrophysiological properties using HEK293 cells. We constructed stable cell lines expressing wild-type (WT) or the SLC4A3 variant based on HEK293 cells. To evaluate the intracellular pH (pHi) level, we measured pHi using BCECF-AM via time-lapse microscopy. To clarify the pathogenesis of the SLC4A3 variant in vivo, we injected CRISPR-Cas9 and a repair template into one-cell stage zebrafish embryos and established a SLC4A3 knock-in (KI) zebrafish model (hereafter referred to as slc4a3 zebrafish). Action potential durations (APD) were recorded in slc4a3 zebrafish at 3 days post-fertilization (dpf).

Results

We identified two novel variants in KCNH2 (c.280 c>t, p.H70Y) and SLC4A3 (c.1059 c>a, p.N353K) in a SQTS patient. Both variants were co-segregated in the patient’s family with short QT intervals (Figure A). By electrophysiological analysis, KCNH2-H70Y did not increase IKr. We over-expressed KCNH2 (WT and H70Y), KCNQ1, and KCNJ2 in the SLC4A3 stable cell lines (WT and N353K) though no increase of IKr, IKs, and IK1 was observed. In the analysis of pHi, cells expressing SLC4A3-N353K showed significantly slower pHi alternations than those with WT, indicating the loss-of-function effect of transport kinetics in the regulation of pHi. In the electrophysiological analysis of the slc4a3 zebrafish, which harbors the paralogous variant of SLC4A3-N353K, APD20, 50, and 70 were significantly shortened in the slc4a3 KI zebrafish (HOMO) compared to the control (WT), providing evidence for the shortened QT interval with the SLC4A3 variant in vivo (Figure B). Furthermore, slc4a3 zebrafish developed severe cardiac edema (HET and HOMO: Figure C, arrows) with no gross morphological defects in other organs, which may indicate the specific role of SLC4A3-N353K in cardiac function.

Conclusion

We identified a novel SLC4A3 variant, p.N353K, in a family with SQTS and revealed its contributions to the pHi control and the shortened APD. Further analysis will be necessary to clarify the mechanism by which SLC4A3-N353K causes QT shortening.
Partial deletion of the Akap1 gene promotes abnormalities in gut barrier function, gut microbiota composition and cardiac function during cardiovascular aging in mice
Authors: Ioele D , Paolillo R , D'apice S , Coretti L , Lama A , Polese P , Carotenuto M , Mattace Raso G , Mollica M , Lembo F , Esposito G , Perrino C
Published: October 2024

Background

Cardiovascular aging is characterized by mitochondrial dysfunction, changes in intestinal permeability and microbiota composition. Mitochondria-targeted A-kinase anchoring proteins (mitoAKAPs) are a group of structurally diverse proteins binding the regulatory subunits of protein kinase A (PKA), and targeting PKA at discrete intracellular locations. We analyzed the effects of global partial genetic deletion of Akap1 on intestinal barrier permeability, microbiota composition, inflammation, and cardiac function during aging in mice.

Purpose

The proposal of this study was to determine the role of mitoAKAPs in the gut-heart axis during cardiovascular aging.

Methods

Young (4-6-month) and old (18-24-month) genetically modified Akap1+/+ and Akap1+/− mice of either sex underwent evaluation of cardiac function by transthoracic echocardiography. To evaluate gut barrier integrity, we analyzed expression levels of intestinal junction proteins occludin (Ocln), zonulin (Tjp1) in colonic samples and FITC-dextran permeability in vivo, circulating levels of Tumor Necrosis Factor-alpha (TNF-alpha), Lipopolysaccharide (LPS), Interleukin-1 (IL-1) and Interleukin-10 (IL-10). Fecal microbial composition was evaluated by Illumina Mi-Seq, Gut microbiota differences based on 16S rDNA sequencing at genus and species taxonomic levels were identified using linear discriminant analysis (LDA) combined with effect size (LEfSe) algorithm. Finally, faecal microbiota transplantation (FMT) was performed for five weeks to test whether modification of gut microbiota composition can affect cardiac function.

Results

A reduction in % left ventricular shortening (FS%) was observed in young and old Akap1+/- mice compared to Akap1+/+ mice. This finding was associated to increased intestinal permeability, as indicated by reduced mRNA levels of Ocln and Tjp1, increased LPS traslocation across intestinal epitelium into blood in 24m Akap1+/- mice compared to Akap1+/+. Through the analysis of the microbial signature, we observed the different bacterial species present in the microbiota of the experimental groups. FMT of bacteria species from old Akap1+/− to young Akap1+/+ mice induced gut abnormalities and cardiac dysfunction, while FMT from young Akap1+/+ donors ameliorated cardiac dysfunction in old Akap1+/+ mice.

Conclusions

MitoAKAPs play a crucial role in the maintenance of intestinal barrier function, gut microbiota composition and cardiac function during aging. Modulation of the composition of the intestinal microbiota influences intestinal permeability and cardiac function. MitoAKAPs could represent an important diagnostic and therapeutic target for cardiac and intestinal dysfunction.
Increased endothelial cell uptake of erythrocyte-derived extracellular vesicles carrying arginase-1 induces endothelial dysfunction in type 2 diabetes
Authors: Collado A , Humoud R , Kontidou E , Swaich J , Yang J , Mahdi A , Tengbom J , Zhou Z , Pernow J
Published: October 2024

Background

Recently, we have demonstrated that red blood cells (RBCs) from individuals with type 2 diabetes (T2D-RBCs) induce endothelial dysfunction. However, the mechanism by which RBCs communicate with the vessel is unknown. Extracellular vesicles (EVs) are actively secreted by practically all cell types, including RBCs, and represent a novel mechanism of intercellular communication. However, the involvement of EVs from RBC in the development of endothelial dysfunction remains to be elucidated.

Purpose

This study was designed to test the hypothesis that EVs are key players in the communication and the transfer of signalling between RBCs and the vascular endothelium to induce endothelial dysfunction in T2D.

Methods

RBCs from T2D patients and age-matched healthy controls (H-RBCs) were incubated for 18h with Krebs-Henseleit buffer (20% haematocrit) for EV release. RBC-derived EVs in the conditioned medium were isolated using a membrane affinity column. The EVs were co-incubated with mouse aortae to evaluate endothelium-dependent relaxation and with endothelial cells for expression analysis. The uptake of the EVs by endothelial cells and their content of arginase-1 were determined. The functional involvement of arginase was investigated using pharmacological interventions and expression analyses. All animal experiments were performed according to the principles of laboratory animal care (NIH Publication no. 85-23 revised 1985) and human procedures according to the declaration of Helsinki with approval by the Swedish Ethical Review Authority.

Results

The uptake of EVs derived from T2D-RBCs by endothelial cells was 2-fold greater than that of EVs from H-RBCs (Fig. 1A-B). Inhibiting the uptake of EVs derived from T2D-RBCs by the addition of heparin during the co-incubation rescued the endothelial function (Fig. 1C). Arginase-1 was detected in RBC-derived EVs (Fig. 2A). Arginase-1 mRNA and protein levels were increased in endothelial cells following co-incubation with EVs derived from T2D-RBCs (Fig. 2B-D). Additionally, the increase in arginase-1 protein induced by EVs derived from T2D-RBCs in endothelial cells was observed also following mRNA silencing for arginase-1 (Fig. 2E-F). Finally, mouse aortae co-incubated with EVs derived from T2D-RBCs in the presence or absence of the arginase inhibitor 2(S)-amino-6-boronohexanoic acid significantly attenuated the impairment in endothelial function induced by EVs derived from T2D-RBCs (Fig. 2G).

Conclusion

Increased uptake of RBC-derived EVs by the endothelial cells is an important feature of the endothelial dysfunction induced by these EVs in T2D. In addition, these EVs carry arginase-1 protein to induce endothelial dysfunction. The mechanism underlying the increased uptake of EVs in target cells is of importance to identify in future studies, as it could lead to new treatment strategies.