bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pulsed field ablation using additional mapping and substrate modification to treat atrial fibrillation - one year outcome comparison
Authors: Mergani M , Mannion J , Healy L , Ramsamy K , Egan S , Boles U 
Published: October 2024

Abstract

Background
Pulsed field ablation (PFA) is a relatively new non-thermal form of ablation employing irreversible cell electroporation as an alternative to radio-frequency ablation. Conventional use of PFA relies on fluoroscopy. Electro-anatomical and voltages mapping (EAM) may potentially provide refinement of PFA via ablation of non-PV targets and accurate localisation of catheter placement. Currently there is limited data on the efficacy of the use of voltages criteria of EAM in conjunction PFA in the treatment of atrial fibrillation.

Objective
The aim of our study was to determine the effect on atrial arrhythmia recurrence with the use of EAM with PFA in patients requiring atrial fibrillation ablation.

Methods
This single centre retrospective observational analysis included one hundred patients with symptomatic AF (paroxysmal and persistent) undergoing ablation for the first time. Fifty patients underwent PFA-PVI alone and fifty patients underwent PFA-PVI with EAM. Data were obtained on patient characteristics, outcomes, procedure details and complications up to one year. A blanking period of three months was used post-ablation. For rhythm monitoring we utilised ECGs and holters at three, six, nine and twelve months and twenty-four hour holter monitoring at six and nine months. We also used remote monitoring in between these periods to record any symptomatic episodes atrial arrhythmias.

Results
Baseline patient characteristics are represented in Table 1. Despite having no significant difference in category of AF between groups (Paroxysmal, persistent, longstanding persistent) the mapping group were significantly older (68.2 years ± 10.2 vs 60.1 ± 11.11; p=0.01), longer duration of documented atrial fibrillation (45.9 ± 50 vs 28.6 ± 38 months; p=0.038), higher risk for CV events with CHA2DS2-VASc score (2.2 ± 1.5 vs 1.42 ± 1.2; p=0.04), however, procedure times were greater in the PVI and mapping group (72.8 ± 6.2 vs 41.1 ± 17 minutes; p=0.03).
Successful PVI was achieved acutely in all patients upon voltage guided mapping validation and most importantly 1 year follow up revealed comparable outcome in both groups (Fig 1).

Conclusion
Patients who underwent PFA with mapping were older, greater co-morbidity and longer duration of AF burden. Yet, the addition of EAM with PFA did demonstrate equivalent achievement of sinus rhythm and was relatively high as higher than 80 % at one year follow up. This study may suggest a preference to using EAM in patients who may be deemed to be older and have a greater co-morbidity. It emerges as a great hope to safer approach and successful intervention to reduce AF burden.mapping vs PVI onlyGraph showing one year follow up
Daily Subcutaneous injections of Relaxin is a therapy for heart failure with preserved ejection fraction
Authors: Salama G , Dschietzig T B D , Gabris-Weber B W , Mcmahon B M , Mauro A M , Romero G R 
Published: October 2024

Abstract
Background and Significance: Relaxin (RLX), a hormone of pregnancy has engendered a great deal of excitement as a therapy for cardiovascular diseases. Clinical trials treated patients with acute decompensated Heart Failure (HF) with RLX (i.v. 30µg/kg/day-2 days) and reported a 37% decrease in mortality during a 6-months follow up. This led the FDA to declare RLX a ‘break-through’ therapy. However, a larger trial failed to meet the sought-after end points. Here, we propose that periodic subQ RLX pulses are more effective. We measured the pharmacokinetics of serum RLX following subQ injections of RLX in Sprague Dawley rats. Further, we treated rats with confirmed HFpEF with daily subQ RLX (2-weeks) to reverse the diastolic dysfunction (DD), arrhythmia and fibrotic profile.

Methods
Sprague-Dawley (250 g, n=20, either sex) received 2-subQ injections 12 hrs apart of RLX (from Relaxera) or the vehicle. Serial blood samples were drawn following each injection to measure [RLX]. ZSF1 rats (9-weeks old, either sex) were placed on a high fat diet (HFD) and serial echos tracked the DD. Once severe DD was established (25-35 weeks of HFD), rats received daily subQ injections of RLX (100µg/kg) or vehicle. After 2-weeks, hearts were perfused to optically map action potentials and Ca2+ transients, and analyze the arrhythmia profile. IF and Westerns were used to measure changes in fibrosis (collagen 1), Nav1.5, connexin 43, Wnt1 and β-catenin.

Results
After an injection, RLX reached a peak in ~60 min, fell to 50% in 5-6 hours. Injections of 0, 30, 100 or 500 µg/kg yielded peak levels of 0, 11.26±3.52, 58.33±16.10, and 209.42±29.04 ng/ml and residual levels after 24-hrs of 0, 4.9, 45.1 and 156 pg/ml, respectively. The 30µg/kg injections had no effect and 100 µg/kg increased Nav1.5 (25%), Cx43 (30%) and β-catenin (90%). The 500 µg/kg injections increased Nav1.5 and Cx43 but upregulated β-catenin, only slightly. In ZSF1 HFpEF rats that received the vehicle (n=12), a premature stimulus (at 30 ms) elicited arrhythmia in 67% of the hearts. RLX injections reversed DD, suppressed sustained atrial and ventricular arrhythmias (n=0/12) but not self-terminating arrhythmias, lasting &lt; 10sec. RLX improved the conduction velocity (CV), particularly at fast rates (100ms) from 0.74 to 0.9 m/s (p&lt;0.001, n=12). RLX significantly increased Cx43 expression, Nav1.5 and β-catenin at intercalated disks. RLX reduced collagen deposition in HFpEF rats, to normal levels and increased Wnt1 compared to control HFpEF rats.

Conclusions
The ZSF1 diabetic rat on a HFD recapitulates human HFpEF, high blood pressure, fibrosis, DD, AF and VF. SubQ RLX injections reversed DD i.e. enlarged Left Atrium, E/e’ ratio, fibrosis, and the arrhythmia vulnerability by increasing CV, Cx43, and Nav1.5. Daily subQ RLX injections were highly effective as a therapy for HFpEF.Echo parameterHFpEF + RLX
The STRIPAK associated kinase MST4 is a novel mediator in heart failure pathogenesis
Authors: Leye M , Eden M , Hahn J , Luzarowski M , Tannert C , Voelschow B , Martini S , Sossalla S , Lucena-Porcel C , Frey N 
Published: October 2024

Abstract

Heart failure still poses substantial challenges in understanding its underlying molecular pathways. We recently found the mammalian STE20-like kinase 4 (MST4) significantly upregulated in human failing hearts (5.7-fold in DCM and 3.8-fold ICM) as well as in heart failure animal models (i.e. 2.5-fold in Calsarcin-1-KO, 2.5-fold in MLP-KO). MST4 is a member of striatin interacting phosphatases and kinases complexes (STRIPAK), an emerging group of multiprotein complexes responsible for integrating cellular signalling pathways. We provide the first evidence of functional STRIPAK complexes containing MST4 by co-immunoprecipitation and interactomics experiments in cardiomyocytes. Moreover, we found MST4 to interact with several intercalated disc proteins like beta-Catenin or Desmin.
Adenoviral overexpression of MST4 in neonatal rat ventricular cardiomyocytes (NRVCM) results in a significant increase in cell size (+13%). This was not accompanied by the activation of fetal genes such as NPPA, NPPB or RCAN1.4, but rather by an increase in phosphorylation of Protein kinase B (PKB/Akt, 3.3-fold). Akt is usually associated with physiological hypertrophy, indicating that MST4 may be involved in protective pathways in cardiomyocytes. In support of this notion, MST4 overexpression reduced apoptotic activity (cleavage of Caspase 3 -69%, Caspase 7 -80%, Parp1 -27%) and improved both contractility (fractional shortening cell +23%, fractional shortening sarcomere +30%, time to max. contraction cell -10%, time to max. contraction sarcomere -12%) and relaxation parameters (time to max. relaxation velocity cell -12%) in isolated adult rat ventricular cardiomyocytes.
In order to identify cardiac targets of MST4, we performed a comprehensive analysis of the phosphoproteome of NRVCM overexpressing MST4 compared with control-virus +/- pharmacological inhibitor at two time points. We identified more than 70,000 peptides including more than 20,000 phosphopeptides in more than 4,000 protein groups. Using linear modelling with a reduced data set containing regulated features selected by thresholds for p-value and fold change, we observed a consistent MST4 effect and a number of enriched gene ontology terms. Here, we found several potential MST4 targets and effects on protein expression levels associated with intercalated disc proteins. In human heart samples, MST4 was also localized to the intercalated disc region by immunostaining. Interesting proteins in that context that might help explain some of the observed cardioprotective MST4 effects are Connexin 43, Desmin, Ryanodine receptor, Phospholemman, Junctophilin2, Myozap or Frizzled 1.
Taken together, our data imply that MST4 upregulation in human heart failure serves an adaptive role which may offer translational opportunities.Graphical Abstract
A novel murine model of stress-induced cardiomyopathy achieved by chemogenetic stimulation of the locus coeruleus-norepinephrine system
Authors: Bengs S , Ministrini S , Liberale L , Duss S , Floriou-Servou A , Portmann A , Rossi A , Mikail N , Puspitasari Y M , Montecucco F , Luescher T F , Bohacek J , Camici G C , Gebhard C 
Published: October 2024

Abstract

Background
Takotsubo syndrome (TTS) is a stress-induced acute cardiomyopathy characterized by transient left ventricular (LV) dysfunction without obstructive coronary artery disease. TTS is often underdiagnosed and undertreated and typically occurs in middle-aged women who recover from initial symptoms within a few weeks. Despite the apparent recovery, TTS patients have a worse cardiovascular prognosis compared to healthy individuals. To date, the pathophysiology underlying TTS remains unclear.
So far, preclinical models barely reflect the complete clinical picture of TTS observed in humans. Moreover, these models display several limitations, e.g., high mortality or disregarding the involvement of the central nervous system. Consequently, much of the current obscurity concerning the pathophysiology of TTS is due to the lack of appropriate preclinical models.

Purpose
The present study aimed to assess whether chemogenetic activation of the locus coeruleus-(LC)-norepinephrine-(NE) system in vivo can induce LV dysfunction similar to that observed in patients with TTS. For this purpose, we used the designer excitatory receptor activated exclusively by designer drug (DREADD) system.

Methods
11-13 weeks-old female Cre-dependent DREADD mice were genetically modified to express a codon-improved Cre recombinase under the dopamine-beta-hydroxylase-(DBH) promoter. For this purpose, a designed excitatory receptor exclusively activated by designer drugs or a control vector was stereotactically delivered to the LC using adenoviral transfection. Restricted expression of DBH-positive noradrenergic neurons to the LC was validated using pupillometry. LC-NE was activated by administering low-dose clozapine 0.03 mg/kg/day intraperitoneally. Serial anatomical and functional assessments of the cardiac phenotype in these mice were performed at baseline, the end of stress induction, and after ten days and three months of the recovery phase using echocardiography and cardiac magnetic resonance imaging.

Results
Targeted stimulation of the LC-NE system resulted in apical LV wall motion abnormality in 70–83% of mice. A complete recovery of LV wall motion abnormality was observed after the recovery phase.

Conclusions
Chemogenetic stimulation of the LC-NE system in mice mimics LV wall abnormalities similar to those observed in patients with TTS and may, therefore, be a novel preclinical model to investigate the pathophysiology of TTS.
Reinterpretation of genetic testing for Cardiomyopathies: Less is more
Authors: Manzoni M , Sommariva E , Pizzamiglio F , Mushtaq S , Bonalumi G , Farina S , Volpe A , Biondi M L , Novelli V 
Published: October 2024

Abstract

Background
In the last years, the concept of reinterpretation of genetic testing has been considered as part of the diagnostic workflow. However, this process requires time, expert curators and new pieces of evidence to evaluate, as functional studies, segregation and allele frequency data.
Last year, the European Society of Cardiology (ESC) published new guidelines for the management of cardiomyopathies. This document includes a precise list of genes associated with the different types of Cardiomyopathies and their level of contribution, according to ClinGen evaluation: definitive/strong, moderate, limited, and refuted/disputed. This document poses a real support in the reinterpretation of tests that report variants in genes not clearly correlated with these phenotypes.

Purpose
To evaluate the impact of the new ESC indications regarding genetic testing, we reconsidered all genetic results performed in our Clinic in patients with confirmed or suspicious Cardiomyopathy.

Methods
From 2017 to 2023 we analyzed 296 probands eligible for Cardiomyopathy genetic testing, in particular: 105 patients were tested for Arrhythmogenic Cardiomyopathy (ACM), 113 for Hypertrophic Cardiomyopathy (HCM) and 78 for Dilated Cardiomyopathy (DCM), using a custom sequencing panel including 44 genes (11 genes for ACM, 34 for DCM and 29 for HCM).

Results
Comparison analysis with the genes reported from the ESC guidelines, considering only the definitive, moderate, and strong genes, showed that 24 genes are not more associated with the phenotype and then not clinically actionable. In this scenario, we reconsidered 12 variants (8%), previously classified as VUS, changing the referral status of 8 patients, from uncertain to negative.

Conclusions
These results highlight the importance of variant reinterpretation as a fundamental step of genetic testing, posing the importance of the selection of the genes to analyze, in order to improve the management of the patients.
A novel murine wire injury based infectious endocarditis model aggravates aortic valve stenosis
Authors: Bartsch B , Nazir M L , Altrogge M , Fester L , Lambertz J , Coburn M , Nickenig G , Zimmer S , Weisheit C K 
Published: October 2024

Abstract

Background
With mortality rates up to 40% under optimal medical treatment, infectious endocarditis (IE) remains one of the deadliest infectious diseases worldwide. In the early stages of IE, diagnosis and treatment initiation are often difficult and research is limited due to unreliable models. Most murine IE models rely on permanent prosthetic wire placement and i.v. bacterial injection, thus making it inadequate to study IE pathophysiology with the aim to reflect the course of disease in humans.

Purpose
To develop a reproducible murine IE model, based on aortic valve injury preceding intravenous S. aureus bacterial challenge.

Methods
Using a wire-injury model we induced endothelial lesions. 72h after wire injury (WI), we performed intravenous bacterial challenge using S. aureus. Echocardiography was performed to confirm bacterial vegetations and assess valvular function. Cross sections of valvular leaflets were prepared for scanning electron microscopy (SEM). Macrophage, neutrophil and S. aureus-specific immunofluorescence staining was performed and visualized by immunofluorescence microscopy. Bacterial cultivation was performed from peripheral blood and valve tissue. Systemic immune response was analyzed using flow cytometry.

Results
WI induced endothelial damage in all mice verified using scanning electron microscopy imaging. The combination of wire injury and injection of 10^5 and 10^6 colonies-forming-units (CFU) S. aureus reliably caused IE validated via in vivo echocardiography as well as S.aureus immunofluorescence staining and SEM imaging. Mice undergoing bacterial challenge responded with significant neutrophilia in the blood. Using 10^6 CFU S. aureus was associated with an increased mortality, liver and kidney abscess formation due to systemic bacterial spreading compared to 10^5 CFU. Peak velocity across the aortic valve and aortic valve leaflet thickness as markers for aortic valve stenosis were increased in IE compared to WI only mice. Aortic regurgitation was more prevalent after bacterial challenge mediating increased left ventricular volumes, meanwhile ejection fraction was not altered. Immunofluorescence staining revealed a pro-inflammatory milieu including increased macrophage and neutrophil infiltration in IE compared to WI only mice.

Conclusion
In vivo echocardiography and ex vivo histological staining revealed reliable IE induction using our new model with S. aureus concentrations of 10^5 CFU. The additional bacterial challenge causes a more severe aortic valve stenosis compared to WI only mice, potentially due to an observed increase in valvular inflammation.Fig 1 Scanning electron microscopy after
Myocardial SGLT2 expression and cardiac remodeling in patients with severe aortic stenosis: the BIO-AS Study
Authors: Paolisso P , Scisciola L , Belmonte M , Gallinoro E , Delrue L , Casselman F , Van Praet V , Torella M , Marfella R , De Feo M , Bartunek J , Paolisso G , Barbato E , Barbieri M , Vanderheyden M 
Published: October 2024

Abstract

Background
Cardiac remodeling plays a major role in the prognosis of patients with aortic stenosis (AS) and could impact the benefits of aortic valve replacement. Blood and tissue biomarkers have a differential pattern and expression level in patients with AS, which may retain a pathophysiological role in cardiac remodeling and metabolism. However, the data available are limited and contradictory.

Aim
Our study aimed to evaluate the expression of sodium-glucose cotransporter 2 (SGLT2) gene and protein in patients with severe AS stratified in high gradient (HG) and low flow-low gradient (LF-LG) AS and its association with cardiac functional impairments.

Methods
Gene expression and protein levels of main biomarkers of cardiac fibrosis (Galectin-3, sST2, Serpin-4, PINP, PICP, Collagen, TGF-b), inflammation (GDF-15, IL-6, NF-kB), oxidative stress (SOD1, SOD2), and cardiac metabolism (NHE, PPAR-a, PPAR-g, GLUT1, and GLUT4) were evaluated in blood samples and heart biopsies of 45 patients with AS.

Results
Our study showed SGLT2 gene and protein hyper-expression in patients with LF-LG AS, compared to controls and HG AS (p&lt;0.05). These differences remained significant even after adjusting for age, gender, body mass index, history of diabetes mellitus, arterial hypertension, and coronary artery disease. SGLT2 gene expression was positively correlated with: i) TGF-b (r=0.72, p&lt;0.001) and collagen (r=0.73, p&lt;0.001) as markers of fibrosis; ii) NF-kB (r=0.36, p&lt;0.01) and myocardial IL-6 (r=0.68, p&lt;0.001) as markers of inflammation: iii) SOD2 (r=-0.38, p&lt;0.006) as a marker of oxidative stress; iv) GLUT4 (r= 0.33, p&lt;0.02) and PPAR-a (r=0.36, p&lt;0.01) as markers of cardiac metabolism (Figure 1).

Conclusion
In patients with LF-LG AS, SGLT2 gene and protein were hyper-expressed in cardiomyocytes and associated with myocardial fibrosis, inflammation, and oxidative stress. The hyper-expression of the SGLT2 gene and protein in patients with LF-LG might pave the way for using SGLT2-Is in this subset population, with the potential to improve the outcomes of AVR and reduce the likelihood of re-hospitalization within one year.Figure 1
Catheter ablation increases cerebral blood flow and cognitive function in elderly patients with atrial fibrillation
Authors: Manita M , Asahi T , Higa N , Zaima S , Arakaki Y , Tabata K 
Published: October 2024

Abstract

Background
Atrial fibrillation (AF) has been considered to have an increased risk for cognitive impairment independent of a stroke and a silent micro-infarction. The mechanism of this interaction is unclear. One of the potential explanations is brain hypoperfusion due to a reduced cardiac output. To date, there are no reports focusing on the cerebral blood flow and cognitive impairment in patients undergoing AF ablation.

Purpose
The purpose of this study was to investigate whether catheter ablation of AF would increase cerebral blood flow and restore cognitive impairment.

Methods
AF patients aged 75 years or older with mild or more cognitive impairment were selected. The assessment of cognitive function using Mini-Mental State Examination (MMSE) and Hasegawa's Dementia Scale-Revised (HDS-R), and measurement of cerebral blood flow using 99mTc-ECD SPECT imaging were examined before and 3 months after ablation.

Results
A total of 25 elderly patients (mean age 83, 14 males and 11 females) were included in this study. Of them, 23 patients had persistent AF. Twenty-three patients (92%) maintained sinus rhythm after ablation. There was a significant improvement in MMSE score (from 24.6±4.5 to 25.9±4.0, p&lt;0.05) and HDS-R (from 23.2±5.5 to 24.8±5.1, p&lt;0.05) after ablation. Cerebral blood flow also significantly increased after ablation (right lobe: from 34.4±4.6 to 38.5±4.4 ml/100g/min, p&lt;0.01, left lobe: from 35.3±9.7 to 38.8±3.7 ml/100g/min, p&lt;0.01). Overall average cerebral blood flow increased by 10.1±9.4% after ablation. There was a positive correlation between the changes in MMSE score and the changes in cerebral blood flow (r=0.65, p&lt;0.05).

Conclusion
AF ablation in elderly patients increased cerebral blood flow and cognitive function. AF ablation would be one of the therapeutic options to improve cognitive function in elderly patients with cognitive impairment.