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Background: In-hospital cardiac arrest (IHCA) is associated with significant morbidity and mortality. The relationships of race/ethnicity and sex to outcomes and treatment patterns among patients with IHCA remain poorly understood. Methods: We conducted a retrospective cohort study using the National Inpatient Sample database from 2016 to 2020 to identify adult patients with IHCA and compare in-hospital outcomes stratified by race/ethnicity (White, Black, Hispanic) and sex. The primary outcome was in-hospital mortality. Secondary outcomes included rates of in-hospital procedures. Multivariable logistic regression was used to adjust for potential confounders. Results: Among 207,770 patients with IHCA, 26.6% had ventricular tachycardia/fibrillation (VT/VF) and 73.4% had pulseless electrical activity (PEA)/asystole. In the VT/VF subgroup, Black males (aOR 1.42, 95% CI 1.21-1.66), Black females (aOR 1.25, 95% CI 1.05-1.50), and Hispanic females (aOR 1.30, 95% CI 1.01-1.66) had higher odds of mortality compared to White males (Figure 1). In the PEA/asystole subgroup, Black males (aOR 1.25, 95% CI 1.11-1.39) and Hispanic males (aOR 1.22, 95% CI 1.07-1.40) had higher odds of mortality, while White females had lower odds (aOR 0.88, 95% CI 0.82-0.94) compared to White males (Figure 2). Black patients were less likely to receive percutaneous coronary intervention (aOR 0.53, 95% CI 0.43-0.66 for males; aOR 0.54, 95% CI 0.42-0.69 for females) and coronary artery bypass grafting (aOR 0.50, 95% CI 0.30-0.82 for males; aOR 0.47, 95% CI 0.27-0.81 for females) compared to White males in VT/VF arrests. Additionally, Black males had the highest adjusted odds of renal replacement therapy in VT/VF arrests (aOR 1.47, 95% CI 1.21-1.80), while Hispanic males had the highest adjusted odds in PEA/asystole arrests (aOR 1.49, 95% CI 1.27-1.74) compared to White males. The remaining outcomes of interest in both VT/VF and PEA/asystole arrests are shown in Figure 1 and Figure 2 respectively. Conclusion: Significant racial/ethnic and sex disparities exist in outcomes and treatment patterns among patients with IHCA, with differences observed in both VT/VF and PEA/asystole subgroups. Targeted efforts and further studies are needed to better understand and address these disparities and improve outcomes in these severely ill patients.

Introduction: Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a genetic disorder characterized by fibrofatty replacement of myocardial tissue, creating areas of electrical heterogeneity and increasing the risk of ventricular arrhythmias (VAs) and sudden cardiac death (SCD). Catheter ablation is commonly performed in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC) for management of ventricular arrhythmias (VAs). Whether catheter ablation affects cardiac function post-procedurally is uncertain. Research Question: Does catheter ablation for ARVC result in acute change in cardiac function? Goals/Aims: To assess the impact of catheter ablation for VAs on cardiac function in the acute post-procedure setting. Methods: This retrospective study included patients with ARVC who underwent catheter ablation for VAs at Mayo Clinic. Cardiac function was assessed on pre- and post-procedure transthoracic echocardiograms (TTEs). Post-procedure TTEs were obtained within 4 weeks after the ablation procedure. Right ventricular (RV) enlargement and systolic dysfunction were evaluated as continuous variables (0=none, 1=mild, 2=mild-moderate, 3=moderate, 4=moderate-severe, 5=severe). Results: The study included 32 patients who underwent a total of 44 ablations. Mean age at the time of ablation was 49±16 years, and 24 (75%) were male. After a mean follow-up duration of 2.6±5.5 days, there was a significant worsening in mean RV dysfunction (1.6±1.5 to 2.0±1.4, P = 0.001). There were no significant changes in mean left ventricular ejection fraction (LVEF), left ventricular (LV) dimensions, and RV size. 6 (14%) patients had a >5% decline in LVEF, and 14 (32%) patients had worsening RV function. Transient inotropic support was required in 4 (9%) patients. Conclusion(s): This study is the first to assess the acute impact of catheter ablation for VAs on cardiac function in ARVC patients. These results underscore the importance of careful post-procedure monitoring and planning of the ablation target in these patients to avoid excessive ablation and therefore impairment in cardiac function.

Introduction: Intracellular calcium handling plays a central role in cardiac contractility and relaxation. Genes such as the Ca 2+ -ATPase pump (SERCA2a) and the Dihydropteridine reductase (DHPR) enzyme are especially important in the cycling of intracellular calcium. As prior research has established a link between treatment with our cardiac targeting peptide (CTP: a 12-amino acid, cardiomyocyte-specific cell penetrating peptide) and upregulation of calcium-handling genes such as SERCA2a and DHPR, we hypothesized that treatment with our novel hybrid cardiac targeting peptide (hCTP: positions #3 and 11 replaced with the D-enantiomer form of the amino acids) will improve intracellular calcium handling in human cardiomyocytes (CMCs) by increasing expression of key calcium handling genes instrumental in sequestering calcium in diastole and lowering cytosolic levels. Methods: To test hCTP’s calcium handling abilities, CMCs were plated on day 1 and allowed to settle for 24 hours, after which they received daily treatment with various concentrations of hCTP (1-25µM) for three days. On day 5, cells underwent either intracellular calcium measurements using the FLIPR 6 Calcium assay or were prepared for western blotting. Western blotting was performed to determine the protein concentrations of SERCA2a and DHPR, as compared to a GAPDH control. To test hCTP’s intrinsic calcium handling abilities, various concentrations of hCTP were mixed with a constant amount of elemental calcium dissolved in water. After 20 min at 37 o C, the concentration of free Ca 2+ was measured with an ABL90 Flex Plus radiometer. Results: In CMCs, treatment with hCTP led to a decrease in cytosolic calcium in a dose dependent fashion; concentrations as low as 1µM led to a significant decrease in cytosolic calcium (p< 0.0001 for all groups). Western blots performed on the treated CMCs revealed an increase in expression of both DHPR and SERCA2a, normalized to GAPDH control. Outside of the cellular environment, hCTP did not appear to display inherent calcium sequestring properties, suggesting that improvements in calcium handling are due to upregulation of gene expression. Conclusion: hCTP appears to lower cytosolic calcium and improve calcium handling through upregulation of SERCA2a and DHPR. Our data indicates that hCTP is worth pursuing as a stand-alone, cardio-selective therapy for cardiomyopathies involving calcium mishandling.

Background: Arrhythmogenic cardiomyopathy (ACM) is a genetic heart disease characterized by fibrofatty replacement of ventricular myocardium. Arrhythmogenic left ventricular (LV) cardiomyopathy (ALVC) is a phenotypic variant of ACM predominantly involving the LV. Mutations in genes encoding for desmosome proteins and filamin C have been implicated in ALVC, especially in the setting of a ring-like late gadolinium enhancement (LGE) imaging pattern. Objective: To identify the underlying genetic substrate responsible for genetically elusive ring-like ALVC in a patient with seemingly sporadic/recessive disease. Methods: A 38-year-old male was referred for genetic investigation to determine the underlying genetic substrate responsible for his ALVC phenotype. The patient fulfilled both electrocardiographic (low voltage in the limb leads and anterolateral T-wave inversions) and imaging (>1 segment of subepicardial LGE) criteria for ALVC. Additionally, the patient experienced unexplained episodes of tachycardia, shakiness, sweating, and nausea prompting concern for an underlying neuromuscular disease. Genome sequencing (GS) was performed on DNA isolated from the affected patient and both of his unaffected parents. Variants were filtered assuming either a sporadic de novo occurrence or an autosomal recessive inheritance pattern. Results: GS identified compound heterozygous GNPTAB variants in the affected patient. A previously reported maternally derived p.Leu257Leu (c.771G>A) variant involving the last nucleotide of exon 7 of the GNPTAB gene and a novel paternally inherited Lys834fs*5 frame-shift variant were identified. The p.Leu257Leu variant has been reported to cause aberrant splicing and exon skipping of the GNPTAB mRNA transcript. Pathogenic variants in the GNPTAB encoded N-acetylglucosamine-1 (GlcNAc)-phosphotransferase subunits alpha/beta cause mucolipidosis type III, a rare recessive lysosomal storage disease characterized by coarse facial features, developmental delay, short stature, skeletal deformities, and cardiac involvement including valvular thickening and cardiomyopathy. Conclusions: Here, using a genome sequencing trio analysis we identified a compound heterozygous GNPTAB pathogenic variants as the underlying genetic substrate in a patient with ring-like ALVC and concomitant neuromuscular disease manifestation. Genome sequencing may identify the genetic etiology responsible for an otherwise undifferentiated diagnosis of cardiomyopathy.

Background: Proton beam irradiation to the ventricular myocardium may enable non-invasive targeting of ventricular tachycardia. Previous work has demonstrated the feasibility of imaging ablation lesion with late gadolinium enhanced (LGE) cardiac magnetic resonance imaging (MRI). Hypothesis: We hypothesize that proton beam irradiation will lead to progressively increasing density of LGE corresponding to lesion formation during follow-up after treatment delivery. Aim: The aim of the current study was to determine the time course of LGE intensity in ventricular myocardium following proton beam therapy. Methods: Eleven swine were irradiated with 40 Gy proton beam in the anterior or lateral left ventricular (LV) followed by LGE cardiac MRI every 4 weeks for up to 24 weeks. After manual contouring of the endocardial and epicardial myocardium, a region of interest (ROI) in the area irradiated with 0-5 Gy was contoured (remote ROI). The mean and standard deviation (SD) of the signal intensity (SI) of the remote ROI were calculated. Light LGE was defined as voxels with SI > mean+2SD but < mean+3SD of the remote ROI, while voxels with SI > mean+3SD of the remote ROI were classified as having dense LGE. Voxels identified as bright due to image artifacts or noise were manually removed. The analysis was conducted in a fashion blinded to swine ID and time point after irradiation. Results: A total of 33 time points were analyzed (3.1 ± 1.4 MRI studies per swine). Figure 1A shows a representative time course of LGE in the same swine, progressing from diffuse light LGE at 8 weeks to dense LGE at 16-24 weeks. Figure 1B demonstrates the proportion of light versus dense LGE across timepoints in irradiated myocardial regions. At 8 weeks, light and dense LGE areas were evenly distributed. At 12 to 24 weeks, dense LGE increased to approximately 75%. The proportion of dense versus light LGE was significantly higher at 12, 16, and 24 weeks, as compared to 8 weeks. Conclusion: In ventricular myocardium, diffuse light LGE evident at 8 weeks progresses to denser LGE at 12-24 weeks following proton beam irradiation corresponding with lesion formation.

Background: Pulsed field ablation (PFA) is an innovative modality for treating arrhythmias that is mostly non-thermal and renders myocardial tissue non-viable by creating pores in cardiac cell membranes. The impact of contact force (CF) on PFA efficacy is not well characterized. Hypothesis: We hypothesize that, while contact is necessary for PFA, increasing CF will not have a significant effect on in vivo ablation lesion size. Aim: We seek to investigate the effects of CF on acute PFA lesions in a beating porcine heart model. Methods: The ventricles of 7 porcine animals were ablated in vivo with PFA (500V, at 20μs for 50 pulses separated by 200ms) using a focal bipolar irrigated ablation catheter and BTX 830 electroporation generator (Harvard Apparatus). CF was measured before and after each PFA application using CARTO 3. Lesions were divided into standard CF (5-15g), high CF (16-30g), and very high CF (>31g). Results: A total of 46 lesions were analyzed. Gross pathology showed no significant difference in maximum width, lesion depth, and lesion volume between the three groups ( Figure 1A-B ). Linear regression showed a decrease of 0.003 mm in depth (depth = -0.003 × CF + 1.8, R = 0.05), an increase of 0.01 mm in width (width = 0.01 × CF + 5.7, R = 0.09), and a decrease of 0.05 mm 3 in volume (volume = -0.05 × CF + 26.8, R = 0.03) for each additional gram of CF ( Figure 1C ). Conclusion: While contact is necessary, increasing CF did not have a significant effect on in-vivo PFA lesion dimensions in a beating porcine heart model.

Background: Pulsed field ablation (PFA) has emerged as an innovative technology for treating cardiac arrhythmias. PFA increases cell permeability, which can lead to apoptosis. Greater PFA energy may be necessary to ablate ventricular myocardium for ventricular tachycardia circuits, but this carries risks of side effects such as gaseous formation (microbubbles) and hemolysis. Ethanol (EtOH) infusion has been used to ablate pathologic myocardial tissues in hypertrophic cardiomyopathy and for refractory arrhythmias. Hypothesis: We hypothesize that PFA in the ventricle can increase EtOH uptake through PFA-generated pores, thereby enhancing ablation efficacy, even at low powers, by utilizing the cell permeability effects of PFA. Aim: The aim of this study is to investigate the effect of local EtOH infusion after PFA on lesion size in porcine ventricles. Methods: The ventricles of five porcine subjects were ablated in vivo with a PFA low power setting (750 V, at 20 μs for 50 pulses separated by 200 ms) using a focal bipolar irrigated ablation catheter and BTX 830 electroporation generator (Harvard Apparatus). After PFA was performed, 2 ml of 90 % EtOH vs. saline (control) was infused through the catheter tip to the site of ablation. We compared the electrograms voltage amplitude reduction before and after PFA, and the ablation lesion characteristics. Results: A total of 10 lesions in the control group and 9 lesions in the EtOH group were analyzed. For the controls, the voltage after PFA was not reduced. In contrast, for the EtOH group, the voltage after PFA was significantly reduced ( Figure 1A ). On gross pathology, there were significant differences in ablation lesion depths and volumes between the 2 lesion sets ( Figure 1A-B ). Conclusion: Local EtOH infusion after ventricular PFA enhanced acute efficacy of electroporation. Concurrent PFA with local EtOH infusion has the potential to improve efficacy without requiring higher energy parameters, thereby reducing PFA risks. Future studies on chronic efficacy are warranted.

Introduction: Atrial fibrillation (AF) is prevalent in patients with atherosclerotic coronary and carotid artery disease and is associated with elevated plasma inflammatory markers, such as Interleukin (IL)-6. In carotid artery atherosclerosis, macrophages are considered a local marker of inflammation. Hypothesis: We hypothesize that AF is independently associated with carotid plaque inflammation. Aims: In patients undergoing carotid endarterectomy (CEA), we aimed to determine whether carotid plaques inflammation is associated with AF. Approach: In this prospective cohort study, consecutive patients with carotid artery disease undergoing CEA were enrolled. From the plaques removed during surgery, fixed in formalin and embedded in paraffin blocks, sections were stained with antibodies against CD68 to detect macrophages (Fig.1A) . Digital copies of the slides were created by Motic Easy Scan and histologically annotated with QuPath. The percentage of CD68+ cells was defined as (CD68+ positive cells/total nuclei) x 100. Flash-frozen plaque segments were analyzed by ELISA for IL-6 concentration. Baseline demographics and clinical data, including AF diagnosis, were extracted from the electronic health records. Results: A total of 106 patients undergoing CEA, with a median age of 73 [67-78] years and comprising 83 (78.3%) males, were included in the study. AF was diagnosed prior to CEA in 13 (12.3%) patients. Univariate logistic regression showed that plaque CD68+ cell content was associated with AF (OR 1.048 [95% CI 1.010 – 1.088]; p = 0.013). Additionally, in Mann-Whitney test IL-6 levels were significantly over twofold higher in plaques of patients with AF compared to those without AF (82.4 [64.9-111.7] pg/mg vs 37.0 [18.4-93.3] pg/mg; p=0.020) (Fig. 1B) . Conclusions: The current study demonstrates an association between carotid atherosclerotic plaque macrophage content, IL6 levels and AF, supporting the role of inflammation in the pathogenesis of AF in these patients. Further studies are needed to determine the potential of plaque inflammation as a therapeutic target in AF.

Introduction: Living in an area with high Area Deprivation Index (ADI) is linked to worse cardiovascular disease (CVD) outcomes. However, the association of ADI with type 2 diabetes (T2D), a major CVD risk factor, is incompletely described. This knowledge may guide primary CVD prevention. Method: Rochester Epidemiology Project is a medical record linkage system of persons in southeast Minnesota and southwest Wisconsin. We identified 253,890 persons (aged 4–98 yrs on July 1, 2015) in 9 counties with >90% population coverage. ADI scores, from 2015 home addresses, were grouped into quartiles of low (Q1) to high (Q4) deprivation. We excluded persons with type 1 diabetes (T1D) or history of T2D and identified new T2D cases (2015-2020) using ICD codes, HbA1c and medications. We examined the association between ADI quartile and risk of incident T2D using Cox regression with persons right censored at death, T2D, T1D or last visit. Models were adjusted for age and gender, and reported adjusted hazard ratios (aHR [95% confidence interval]). Results: Age, gender, and race statistically differed across ADI quartiles (Table). Age × ADI interaction was significant ( P <.001). T2D incidence ranged from 6.3 (Q1) to 9.0 (Q4) per 1000 person-years ( P <.001). Women vs. men/non-binary persons (combined due to limited non-binary persons) had 30% lower risk of incident T2D (aHR 0.70 [0.67–0.72]). Risk of incident T2D was higher in persons from higher ADI areas. At median age of 48.6 yrs, the risk was 30% higher in Q2 (aHR 1.3 [1.22–1.38]), 38% higher in Q3 (aHR 1.38 [1.30–1.47]) and 53% higher in Q4 (aHR 1.53 [1.43–1.62]) vs. Q1. Higher ADI was associated with higher incident T2D in younger persons, with risk attenuation with increasing age (Figure). Conclusion: In this population cohort, persons, particularly of younger age, living in more deprived areas had a higher risk of incident T2D. ADI may help identify areas for targeted T2D screening, with implications for CVD screening and prevention.

Background: Hypertriglyceridemia, a common lipid disorder linked to increased risks of cardiovascular diseases and metabolic syndrome, remains a global health challenge. Traditional treatments, though widely used, often have limited efficacy and adverse effects. Olezarsen, a novel antisense oligonucleotide, targets apolipoprotein C-III and shows promise in significantly reducing triglyceride levels. Aim: To conduct a meta-analysis comparing Olezarsen with placebo in patients with hypertriglyceridemia. Methods: We performed an extensive literature search of PubMed, EMBASE, and Cochrane Library databases up to May 2024 to identify studies comparing Olezarsen and placebo in patients with hypertriglyceridemia, irrespective of comorbid cardiovascular disease. Effect estimates were pooled using a random-effects model and reported as risk ratios (RR) for dichotomous outcomes and standard mean differences (SMD) for continuous outcomes, with 95% confidence intervals (CIs) for each. Results: Three randomized controlled trials (RCTs) with a total of 334 participants were included. Olezarsen significantly reduced triglyceride levels at 6 months (SMD: -1.69; 95% CI -2.22 to -1.17; P < 0.00001; Figure ) and 12 months (SMD: -1.64; 95% CI -2.22 to -1.07; P < 0.00001; Figure ). VLDL levels also decreased at 6 months (SMD: -1.95; 95% CI -2.38 to -1.51; P < 0.00001) and 12 months (SMD: -0.83; 95% CI -1.13 to -0.53; P < 0.00001). Lipid profile improvements included reductions in total cholesterol, non-HDL cholesterol, and apoB levels, with increases in HDL cholesterol and apoA-1. Adverse events were comparable between Olezarsen and placebo, although serious adverse events were significantly higher in the Olezarsen group (RR: 2.55; 95% CI 1.17 to 5.58; p = 0.02). Conclusion: Olezarsen demonstrates significant efficacy in reducing triglyceride and VLDL levels while improving overall lipid profiles in hypertriglyceridemia patients. Despite higher rates of serious adverse events, its overall safety profile remains acceptable.