bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 17228: Rassf1A Inhibits Akt Activation in Cardiac Fibroblasts and Protects Against Ischemia Reperfusion Injury in the Heart
Authors: Del Re Dominic , Zhai Peiyong , Sadoshima Junichi
Published: April 2024

Our previous work demonstrated Rassf1A to be a critical mediator of Mst1 activation, the chief component of the mammalian Hippo pathway, in heart failure. In the setting of ischemia/reperfusion (I/R) injury, Mst1 is robustly activated and promotes injury in the heart; however, its regulation remains unclear. Using genetically modified mice in which expression of Rassf1A is altered in a cell type-specific manner, we demonstrate that systemic deletion of
rassf1a
-/-
(KO) does not alter infarct size (36±4% vs 33±3%) or cardiac myocyte apoptosis (1.7±0.2% vs 2.1±0.4%) following I/R versus WT. Conversely, mice harboring deletion of
rassf1a
in cardiac myocytes (
rassf1a
flox/flox
αMHC-Cre, CKO) have smaller infarcts (23±2 vs 38±3%, p<0.05) and less apoptosis (0.9±0.2 vs 2.0±0.2%, p<0.05) after I/R. Importantly, attenuation of Mst1 activation in ventricular homogenates was observed in both deletion models, implicating Rassf1A as a positive regulator of Mst1 during I/R. Langendorff global I/R injury yielded similar results - no protection in KO, yet significant protection in CKO hearts versus control mice, suggesting that native cardiac cells are sufficient to mediate this response. Using isolated cardiac fibroblast cultures we determined that Rassf1A negatively regulates activation of Akt in response to oxidative stress. Further, knockdown of endogenous Rassf1A causes increased NF-κB activity, a response mediated by Akt. A candidate molecule screen found exaggerated TNF-α expression in non-myocytes of KO hearts compared to WT (4.8±0.7fold, p<0.05), whereas TNF-α expression was attenuated in CKO hearts (reduced 65±8% vs control, p<0.05). Finally, WT and KO mice were administered TNF-α neutralizing antibody or control IgG and subjected to I/R. KO hearts treated with TNF-α Ab, but not IgG, had reduced infarcts (19±4% vs 34±5%, p<0.05), but no significant reduction in infarct size was observed in WT mice given TNF-α Ab. Taken together these data suggest that TNF-α blockade prevents the deleterious consequences of Rassf1A deletion in non-myocytes while unmasking the protective effect of Rassf1A deletion in cardiac myocytes following I/R. Further, these results demonstrate the importance of non-myocytes in modulating cardiac myocyte survival and I/R injury
Abstract 17232: Amiodarone Inhibits Small Conductance Ca
2+
-Activated K
+
(SK2) Channel Expressed in HEK-293 Cells
Authors: Turker Isik , Chang Po-Cheng , Chen Zhenhui , Chen Peng-Sheng , Ai Tomohiko
Published: April 2024

Introduction:
Our recent study showed that apamin-sensitive K+ currents (IKAS), mainly carried by SK2 channel, is upregulated in failing ventricles. IKAS upregulation predisposes heart failure patients to recurrent ventricular fibrillation (electrical storm) by shortening of the action potential duration after initial successful defibrillation. Amiodarone is the drug of choice for the treatment of electrical storms.

Hypothesis:
Amiodarone can inhibit SK2 currents at therapeutic concentrations.

Methods:
The pCMV6 plasmids containing human KCNN2, the gene encoding SK2 channel (transcript variant 1:
NM_021614
), were cotransfected with the pcDNA3 plasmids containing GFP into HEK-293 cells using Lipofectamine 2000. Effects of amiodarone were studied using whole-cell and inside-out mode of patch-clamp methods at 36°C. SK2 currents were induced with voltage-pulse protocols and various concentrations of intracellular Ca2+.

Results:
The whole-cell SK2 currents showed Ca2+-dependency (IKAS at +40 mV: 25.5 ± 9.7 pA/pF with 250 nM [Ca2+]i, n = 5; 60.4 ± 24.9 pA/pF with 500 nM [Ca2+]i, n = 5; 180.0 ± 16.9 pA/pF with 1 µM [Ca2+]i, n = 15). Amiodarone inhibited the SK2 currents activated with 1 µM intrapipette Ca2+ in a dose-dependent manner (IC50, 1.73 ± 0.01 µM, Hill coefficient, 1.28 ± 0.01, total n = 15), and the block was not voltage-dependent. The maximal inhibition was observed with 50 µM amiodarone, and 70.0 ± 7.2% of IKAS was inhibited with 1 µM intrapipette Ca2+ (n = 15). The inhibitory effects of amiodarone on the IKAS with 500 nM intrapipette Ca2+ was similar (66.0 ± 8.6% at 40 mV, n = 5). However, we did not observe any inhibition of the IKAS with 250 nM intrapipette Ca2+ (n = 5). Interestingly, amiodarone did not inhibit the inside-out SK2 currents (n = 3).

Conclusions:
Amiodarone inhibits SK2 channel at therapeutic concentrations. The SK2 blocking effects may explain the efficacy of amiodarone in treating electrical storm.
Abstract 17234: The EFFICAS Studies: Reducing Low Force-Time Integral (FTI) Radiofrequency Applications Improves Procedural Efficacy During Pulmonary Vein Isolation
Authors: Wissner Erik , Petru Jan , Metzner Andreas , Peichel Petr , Soranno Mary , Lambert Hendrik , Kautzner Josef , Neuzil Petr , Kuck Karl-Heinz
Published: April 2024

Objectives
Results of the EFFICAS I study illustrate that in patients with paroxysmal atrial fibrillation (PAF) undergoing pulmonary vein isolation (PVI), ablation using low Force-Time Integral (FTI <400 gs) predicts early gap formation. The EFFICAS II multicenter study prospectively evaluated whether limiting the number of low FTI ablations during PVI improves procedural efficacy.

Methods
Patients with PAF underwent PVI using an ablation catheter with an integrated Contact Force (CF) sensor (TactiCath®, Endosense, Switzerland). Operators were requested to start ablation when CF was ≥ 10 g and to avoid ablations with FTI < 400 gs, thereby demonstrating good catheter stability. Procedure duration, RF ablation time, number of ablations for PVI and fluoroscopy time were compared between EFFICAS I and EFFICAS II.

Results
Five operators in 3 centers treated 30 patients in EFFICAS I and 34 patients in EFFICAS II. All PVs (100%) were isolated at the end of the procedure. In EFFICAS I, 42% of 2060 ablations were performed with an FTI < 400 gs, compared to 18% of 1860 ablations applied in EFFICAS II. There was a statistically significant reduction in RF ablation time, number of ablations, and fluoroscopy time in EFFICAS II as compared to EFFICAS I (table).

Conclusions
Reducing the number of radiofrequency ablations with an FTI < 400 gs increases the efficacy of ablation during PVI. Whether more effective ablation will increase safety and improve outcome following PVI needs to be determined.
Abstract 17243: Increased Survival in Patients with Right Ventricular Pacemakers Treated with Renin-Angiotensin-Aldosterone System Blockade
Authors: Elder Douglas , Lang Chim C , Choy Anna-Maria
Published: April 2024

Background:
Right ventricular apical pacing can cause ventricular dyssynchrony and pacing-induced heart disease that is associated with worse cardiovascular outcomes. In an animal pacing model angiotensin converting enzyme inhibitors (ACEI) diminished left ventricular dyssynchrony reduction in afterload and left-ventricular wall stress and reduction in myocardial fibrosis. The impact of ACEI in paced patients is unknown.

Objectives:
To investigate the impact of ACEI/ARB on survival in a retrospective observational study of paced patients.

Methods:
The Tayside Pacemaker Registry was linked to dispensed prescribing, laboratory, echocardiography, hospital admission data as well as and the national death registry. All patients undergoing right ventricular pacemaker insertion between 1994 and 2009 who had never received ACE-I/ARB prior to pacing were included. Patients with heart failure prior to implant were excluded. Cox regression was used to assess differences in all-cause mortality between those on ACE-I/ARB versus those who had never received ACE-I/ARB, adjusted for confounding variables. A propensity score matched analysis was performed to minimise bias.

Results:
3815 patients implanted between 1994 and 2008, 1186 (median age 78, range 18-103yrs, 53% males) met inclusion criteria (63% DDD and 37% VVI). Mean follow-up was 5.3 ± 4.0 years with 484 (41%) deaths. ACEI/ARB was associated with significantly reduced mortality (adjusted HR 0.68, 95%CI [0.54-0.87],p<0.001). In a propensity score matched analysis of 805 individuals the HR was (0.57, 95%CI [0.46-0.71], p=0.001).

Conclusions:
This study suggests prescription of ACEI/ARBs may confer benefits on survival in patients with right ventricular pacemakers.
Abstract 17248: Risk Factors for Cardiovascular Disease in Inmates
Authors: Connell Alison , Chung Misook L , Lennie Terry A , Bailey Alison , Moser Debra
Published: April 2024

Background:
In the United States 1 out of every 100 males are imprisoned with federally mandated health care provided by the prison. Inmates tend to have high tobacco, alcohol and drug use but other risk factors have not been reported. The purpose of this study was to determine if a self-rated general health question was associated with lipid levels and modifiable risk factors of inmates.

Method:
A total of 304 male inmates (ages 19-77; M = 36 ± 9.7) in four medium security state prisons completed the Inmate Health Risk Assessment, comprised of 10 items on tobacco use, diet, exercise, stress, social support and coping. Categorical responses were rated from 1-3 giving a possible range of 10 to 30 with lower scores indicating healthier life-styles. The general health question had a 5-point Likert scale from excellent to poor. Finger stick lipid panel was obtained for high density lipoprotein (HDL), low density lipoprotein (LDL), total cholesterol, and triglycerides.

Results:
The single general health item was associated with HDL, triglyceride levels and the total cholesterol-to-HDL ratio (p < 0.001) but not with total cholesterol (p = .07) or LDL (p=.32). The mean score on the IHRA was 18.3 (
SD
= 3.3). Perception of poorer health on the general health question was associated with increased scores on the IHRA (p = < 0.001) after controlling for age, ethnicity, marital status and education level.

Conclusion:
Inmates who reported a perception of poor health had more modifiable lifestyle risk factors such as tobacco use, poor coping, sedentary lifestyle, and poor nutrition than those with perceptions of good to excellent health. Perception of poor health was associated with lower HDL and higher triglyceride levels. The single general health question may be useful for prison health care providers to target behavioral interventions that can improve cardiovascular health in inmates.
Abstract 17258: Incremental Value of Coronary CT Angiography over Calcium Score in Predicting Intermediate-Term Outcomes and Resource Utilization
Authors: Chinnaiyan Kavitha M , Gallagher Michael J , Abbas Amr E , Raff Gilbert L
Published: April 2024

Background:
Prognostic utility of coronary artery calcium (CAC) is well-established. The incremental value of CAD severity assessed by coronary CT angiography (CCTA) over CAC is not well known.

Methods:
This retrospective analysis included patients who underwent CAC + CCTA at our institution and had complete 2-year follow-up. The study group was divided into four: CAC ≤400 + stenosis ≤50% (Group I), CAC ≤400 + stenosis >50% (Group II), CAC >400 + stenosis ≤50% (Group III) and CAC >400 + stenosis >50% (Group IV). Baseline demographics and 2-year follow-up data were compared among the groups for downstream major adverse cardiac events (MACE) (death, acute coronary syndromes and revascularization) and total resource utilization (CAD-related hospitalizations and emergency department (ED) evaluations, stress testing, invasive coronary angiography (ICA) and surgical or percutaneous revascularization).

Results:
The study group included 1496 patients (mean age 56 ± 12 years, 54% males) who underwent CAC and CCTA. Distribution among the four groups were: Group I = 1092 (73%), Group II = 236 (15.7%), Group III = 102 (6.8%) and Group IV = 66 (4.4%). Patients in Groups II and IV (stenosis >50%) were more frequently male, older, diabetic, hypertensive and dyslipidemic (all p<0.0001). At 2 years, patients in Groups II and IV had higher rates of MACE as well as resource utilization (p<0.0001). On stepwise multivariable analysis of Framingham Risk Score, additional risk factors (peripheral, cerebrovascular and chronic obstructive lung disease), symptoms, CAC and CCTA findings, stenosis >50% on CCTA alone was the strongest predictor of MACE and resource utilization, with significant incremental value over the combined effect of all clinical variables and CAC (Figure).

Conclusions:
CAD severity assessed by CCTA provides significant and incremental value over clinical risk scoring and CAC for predicting MACE and resource utilization at intermediate-term follow-up.
Abstract 17284: Selective Macrophage Ablation Attenuates Diet-Induced Obesity and Insulin Resistance and Reverses Diabetic Cardiomyopathy
Authors: Goel Mehak , Hamid Tariq , Ismahil Mohamed Ameen , Zhou Guihua , Brittian Kenneth , Clair Heather , Guo Shangzhi , Prabhu Sumanth D
Published: April 2024

Although activated macrophages infiltrate the heart and adipose tissue in type 2 diabetes (T2D), the role of these cells in the genesis of cardiomyopathic phenotype is unknown. We tested the hypothesis that activated resident macrophages are fundamental mediators of diet-induced diabetic cardiomyopathy. Transgenic mice expressing an AP20187-inducible Fas-dependent suicide gene in macrophages and dendritic cells (MAFIA mice) were fed a high fat diet (HFD, 45% kcal fat) or control diet (CD, 10% kcal fat) for 28 weeks to induce T2D, and subsequently given either vehicle or AP20187 (0.5mg/kg IP every 10 d) for one month to induce macrophage apoptosis and depletion. HFD-fed mice exhibited a significant (p < 0.05) 43% increase in body weight when compared to CD fed mice (43±5 vs 35±1 g) and developed hyperglycemia (199±44 vs 121±10 mg/dL), hyperinsulinemia (1.27±0.6 vs 0.43±0.14 µg/L) and decreased insulin sensitivity indicating T2D. Echocardiography revealed concentric LV hypertrophy in HFD-fed mice with increased wall thickness (anterior wall 1.2±0.1 vs 0.9±0.1 mm), decreased LV end-diastolic diameter (LVEDD 3.9±0.2 vs 4.2±0.4 mm), and unchanged LV ejection fraction. AP20187 treatment significantly reduced the caloric intake (0.3±0.08 vs 0.4±0.05 kcal/g/day) and body weight of HFD-fed mice (36±2 vs 47±5 g), attenuated hyperglycemia (108±8 vs 195±14 mg/dL) and hyperinsulinemia (0.6±0.2 vs 1.9±0.5 µg/L), and improved insulin sensitivity when compared to vehicle treated HFD-fed mice. Importantly, the improvements in metabolic parameters were accompanied by reversal of LV remodeling with decreased wall thickness (anterior wall 0.8±0.1 vs 1.3±0.1 mm) and increased LVEDD (4.6±0.5 vs 3.9±0.2 mm). White adipose tissue weights in AP20187-treated HFD-fed mice were also significantly decreased when compared to vehicle treated HFD-fed mice [epididymal (0.6±0.2 vs 1.4±0.3 g); inguinal (0.6±0.2 vs 1.1±0.3 g); retroperitoneal (0.8±0.5 vs 1.4±0.4 g). We conclude that resident activated macrophages play central and causative roles in the development of diet-induced T2D and diabetic cardiomyopathy. Targeting systemic macrophage activation may represent a therapeutic approach to reverse pathological cardiac remodeling associated with T2D and obesity.
Abstract 17298: MicroRNA-411 Targets Foxo1 to Induce Hepatic Glucose Production in Type 2 Diabetes
Authors: Adi Nikhil C , Adi Jennipher N , Kurlansky Paul , Agatston Arthur , Webster Keith A
Published: April 2024

Introduction:
miRNAs are a class of short, NC, single-stranded RNA molecules that negatively regulate gene expression. A hallmark of T2D is excessive HGP that plays an important role in the development of hyperglycemia and hyperlipidemia. FOXO1 has been shown to bind directly to the promoters of gluconeogenic genes and activate HGP.

Hypothesis:
miR-411 is down regulated in liver of mice with polygenic susceptibility for T2D leading to FOXO1 OE and induction of gluconeogenesis.

Methods:
NONcNZO10 (NZ10) mice with polygenic susceptibility to T2D or SWR controls were fed Control (CD) or South Beach (SD; high protein/unsaturated fat) diets for 25 weeks. After 12 hr. fasting the mice were sacrificed and liver was collected. Total RNA was isolated and subjected to Sanger 14 multi-species miRNA microarray.

RESULTS:
Diabesity was not induced in control SWR mice fed either diet or in NZ10 mice fed SD as evidenced by serum glucose and insulin levels and normal GTT. NZ10 mice fed CD were hyperglycemic (blood glucose >350mg/dL) with impaired GTT and hyperinsulinemia; gene expression analysis showed significant induction of key gluconeogenic genes; PEPCK, G6Pase and FBP1 in the livers of these mice (all, p<0.05). Protein and mRNA levels of FOXO1 were significantly up-regulated in the liver of these mice (p<0.05). Western blot analysis showed significantly increased glycogen phosphorylase and decreased glycogen synthase in livers of insulin-treated NZ10 mice fed CD, with increased CREB-133 phosphorylation and suppressed phosphorylation of AMPKα (all p<0.05). NZ10 mice fed CD had fatty liver and elevated gene transcripts of SREBF1 and PGC1alpha. miRNA analysis showed significant down-regulation of miR-411 in liver of NZ10 mice fed CD (p<0.05).
In Silico
analysis using Targetscan revealed FOXO1 as a target for miR-411. Overexpression of miR-411 in HepG2 cells eliminated FOXO1 expression and suppressed the expression of gluconeogenic enzymes.

Conclusions:
miR-411 targets FOXO1 and negatively regulates the expression of gluconeogenic genes. In NZ10 mice fed CD miR-411 is down-regulated causing hyperglycemia; this can be prevented by SD that promotes glucose homeostasis and reversal of the diabetic phenotype.
Abstract 17318: Caspase Inhibition Prevents Hypertrophy and Improves Cardiac Function with Chronic Pressure Overload
Authors: Park Misun , Lee Jung Ah , Gao Shumin , Yoon SeongHun , Xie Lai-Hua , Charles Ludny , Leibovich Samuel J , Kitsis Richard N , Vatner Stephen F. , Vatner Dorothy E.
Published: April 2024

It is widely held that a major mechanism underlying the transition from stable left ventricular (LV) function to failure is myocyte loss through apoptosis. To test this hypothesis, we examined the effects of chronic transverse aortic constriction (TAC) in C57BL/6 mice with or without administration of the caspase inhibitor (CI) (Z-Asp-2,6-DCBMk) delivered through an intraperitoneal osmotic minipump. In mice treated with CI, LV function (LV ejection fraction) was preserved (73±1%) compared with the vehicle group (52±7%) (p<0.05) after 2 weeks of TAC. One possibility was that CI prevented apoptosis of myocytes and thereby improved LV function. This was not likely, since with CI, apoptosis was reduced, but relatively trivially in myocytes; using double staining with TUNEL and wheat germ agglutinin, only 7% of the reduced cellular apoptosis in the heart could be attributed to myocytes as compared with 93% of non-myocytes protected. Furthermore, if myocyte apoptosis protection was the mechanism, then LV mass would likely have been larger with CI. However, the reverse occurred, i.e., CI actually prevented LV hypertrophy; LV weight/tibial length did not increase significantly with CI after TAC (5.26±0.30) vs. sham (4.95±0.30) as opposed to vehicle after TAC (7.49±0.43). This was not because of differences in LV/aortic pressure gradient in CI (102±4mmHg) vs. vehicle (100±2mmHg), but likely due to protected LV wall stress, which was less (p<0.05) in the CI group (70.2±9.9 Kdyn/cm
2
) than vehicle (132.2±19.4 Kdyn/cm
2
). Therefore, the mechanism for improved function with TAC and CI was likely related to an effect of CI on myocytes. Accordingly, we examined isolated myocytes using a Langendorff perfusion apparatus, and measured isolated myocyte contractility by an optical edge-tracking method. After TAC the contractility (% of cell length) under 1mM calcium was increased in CI (15.5±1.2%) compared to vehicle (10.2±1.4%) (p<0.01). Thus, CI improved LV function after chronic pressure overload, not by protecting against myocyte apoptosis, but rather by improving myocyte contractile function resulting in reduced LV wall stress and hypertrophy.
Abstract 17341: Use and Effectiveness of Drug-Eluting versus Bare Metal Stents in Saphenous Vein Bypass Graft Percutaneous Coronary Interventions: Insights from the National VA Clinical Assessment, Reporting and Tracking (CART) Program
Authors: Tsai Thomas T , Maddox Thomas M , Nallamothu Brahmajee K , Stanislawski Maggie A , Adams Jill C , Box Tamara L , Ho P. Michael , Rao Sunil V , Casserly Ivan P , Rumsfeld John S , Brilakis Emmanouil S
Published: April 2024

Background:
Little is known about the use and outcomes of drug eluting stents (DES) versus bare metal stents (BMS) in saphenous vein graft (SVG) percutaneous coronary interventions (PCI).

Methods:
From the National VA CART program database of 59 catheterization laboratories, we identified all VA patients undergoing SVG PCI (n=2636). Based on a propensity score to receive a DES, we identified a matched cohort of 920 patients who received a DES to 920 patients who received a BMS (n=1840 total) during an index SVG PCI between October, 2004 and September, 2010. Kaplan-Meier analyses were performed to determine the association of DES vs BMS use and follow-up myocardial infarction, revascularization and death.

Results:
SVG PCI represented 7.3% of the total PCI volume (2636 of 36,256 patients). Of these, 1615 (61.2%) were treated with a DES and embolic protection devices were successfully used in 32.5% of patients. In the propensity matched cohort, the 2-year rate of MI was significantly lower among patients who received DES versus BMS (19% vs 23.9%, p=0.005) (Figures). However, the 2 year mortality and revascularization rates were not significantly different in the DES versus BMS groups respectively (9.2% vs 12.0%, p= 0.14 and 22.3% vs 20.6%, p=0.24).

Conclusion:
In a large national SVG-PCI registry, DES compared to BMS use was associated with lower rates of MI but similar revascularization and death rates.
Abstract 17373: MicroRNA-155 Over-expression Inhibits Angiogenesis Of Lin
-
/cd34
+
Cells From Human CAD Patients and HUVECs
Authors: Adi Jennipher N , Adi Nikhil C , Webster Keith A
Published: April 2024

Introduction:
In the cellular hypothesis of atherosclerosis, bone marrow (BM) derived EPCs contribute to vascular repair and regeneration, and defects in number and/or function of EPCs may contribute to the progression of atherosclerosis and coronary artery disease (CAD). Autologous stem cell therapy for CAD requires functionally competent EPCs. Micro-RNAs (miRs) have been implicated in the regulation of angiogenesis; miR-155 is activated by inflammatory cytokines.

Hypothesis:
Dysregulated expression of miR-155 in response to an inflammatory environment within the BM of CAD patients causes functional defects in BM-derived EPCs that promote CAD progression and impairment of autologous stem cell therapy.

Objective:
To quantify the level of miR-155 in EPCs from CAD patients and functionally characterize the effects of miR 155 over-expression on the angiogenic potential of Lin
-
/CD34
+
cells and HUVECs.

Methods:
BM was collected from 5 CAD, 4 non-CAD patients and healthy volunteers; Lin
-
/CD34
+
cells were isolated and subjected to microarray and micro-RNA profiling. HUVECs were transfected with pre and anti-miRs of miR-155. HUVEC tube formation, proliferation and cell death were quantified. Protein and RNA were quantified by western blot and RT-PCR.

Results:
Microarray and RT-PCR confirmed >5-fold up regulation of miR-155 in Lin
-
/CD34
+
cells of CAD patients compared with non-CAD (p<0.05). MiR-155 knockdown in HUVECs increased HIF1alpha and CCND1 protein as measured by western blot (p<0.05). MiR-155 over-expression using precursor molecules significantly inhibited tube formation and cell proliferation of HUVECs (both p<0.01). LDH assay revealed an increase in cell death of HUVECs transfected with pre-miR-155 (p<0.05). The results are consistent with other studies showing that miR-155 regulates multiple biological processes including cell differentiation, survival, and cell migration and extrapolate this to suppression of angiogenesis.

Conclusion:
The expression of miR-155 is markedly increased in CD34+/Lin- EPCs from patients with CAD. miR-155 over expression represses angiogenesis and may drive disease progression. Neutralization of miR-155 over-expression in EPCs is predicted to improve autologous stem cell therapy for CAD.
Abstract 17375: Subnanomolar Concentrations of Urocortin Induce Expression and Release of IL-6 Leading to STAT3 Activation
Authors: Yuan Zhaokan , Chen-Scarabelli Carol , Faggian Giuseppe , Saravolatz Louis , Scarabelli Gabriele , Shieh Wen-Shi , Waqas Qureshi , Mazzucco Alessandro , Saravolatz Louis , Scarabelli Tiziano M
Published: April 2024

Background:
We recently showed that short-term treatment with urocortin (Ucn) of HL-1 cells induces Src-mediated phosphorylation and subsequent nuclear translocation of Signal Transducer and Activator of Transcription (STAT)3. In breast cancer cells, STAT3 was found to be activated by IL-6, while Ucn was shown to stimulate IL-1β and IL-6 secretion from mononuclear inflammatory cells.

Aim:
To verify whether cardiac myocytes can express and secrete IL-6, and, if so, to investigate the role of IL-6 in Ucn-mediated STAT3 activation.

Methods and Results:
Immortalized mouse atrial HL-1 cardiomyocytes were cultured in Claycomb medium supplemented with 10% fetal bovine serum, before being serum-starved for 16 to 20 hours. IL-6 enzyme-linked immunosorbent assay (ELISA) of the conditioned medium from starved HL-1 cells showed that 16 and 24 hours treatment with 10 nM Ucn increased the secretion of IL-6 to 162.9±8.0% and 235.3±34.5%, respectively, as compared to control cells. Conversely, Ucn did not induce the release in the culture medium of IL-1β, as documented by IL-1β ELISA. Quantitative real-time PCR also confirmed the increased expression of IL-6 at the mRNA level. Interestingly, a concentration of Ucn as low as 0.01 nM, which was not sufficient to activate Src kinase, could indeed induce the expression and secretion of IL-6 by 275.7±9.4%. Moreover, transAM STAT3 transcription factor assay (ELISA) and Western blot analysis of HL-1 nuclear extracts showed that 100 nM Ucn increased the nuclear translocation of STAT3 by 132.2±10.9% and 2.6 folds, respectively. STAT3 nuclear translocation was significantly reduced, though not abrogated, by incubation of HL-1 cells with 2 μ g/ml of anti-IL-6 polyclonal antibody (109.1±10.2% and 1.1 folds, respectively).

Conclusions:
We report for the first time that incubation of HL-1 cells with subnanomolar concentrations of Ucn induced the expression and secretion of IL-6, which resulted in STAT3 activation via an autocrine/paracrine mechanism, independent from Src activation.
Abstract 17392: High-Sensitivity Troponin T Predicts Recurrent Cardiovascular Disease Events in Stable Coronary Heart Disease Patients: 8-Year Follow-Up of the KAROLA Study
Authors: Koenig Wolfgang , Breitling Lutz , Brenner Hermann , Rothenbacher Dietrich
Published: April 2024

Purpose:
The clinical relevance of only slightly elevated circulating troponin levels in patients with stable coronary heart disease (CHD) several weeks after an acute event has not been fully evaluated. We aimed to assess the predictive value of a new high-sensitivity troponin T assay (hsTnT) for recurrent cardiovascular disease (CVD) events in stable CHD patients, simultaneously controlling for a large number of potential confounders.

Methods:
Plasma concentrations of hsTnT (Roche Elecsys 2010) were measured at baseline in a cohort of 1,050 patients aged 30-70 years with CHD. The Cox proportional hazards model was used to determine the prognostic value of hsTnT on a combined CVD endpoint after adjustment for covariates.

Results:
The median hsTnT level was 10.9 ng/L (IQR 5.1-18.9). Elevated hsTnT levels were associated with higher age, history of hypertension, history of diabetes, a higher number of affected vessels, initial management of CHD, and left-ventricular dysfunction. In addition as determined by 12-lead routine ECG, rhythm disorders, and anterior wall infarction were associated with higher hsTnT levels. Furthermore, hsTnT was highly correlated with NT-proBNP and cystatin C (R=0.61 and R=0.32, respectively, both p-values <0.0001). During a median follow-up of 8.1 years, 150 patients (21.0%) experienced a fatal- or non-fatal secondary CVD event. In a multivariate model, hsTnT was associated with a hazard ratio (HR) for secondary CVD events of 2.83 (95% CI, 1.68-4.79) when extreme quartiles were compared. Further adjustment for cystatin C, NT-proBNP, and CRP attenuated the association only slightly (2.27; 95% CI, 1.31-3.95), p for trend <0.002). ROC analysis of a clinical model which included hsTnT to a baseline model showed a modest improvement in the AUC (0.69 vs 0.67).

Conclusions:
Slightly elevated hsTnT levels in stable CHD patients are associated with a number of CVD disorders and predict long-term CVD events in these patients.
Abstract 17400: Charge-Stabilized Nanostructures Reduce Ischemia-Reperfusion Injury in A Pig Model in vivo
Authors: Kalmes Andreas , Ghosh Supruna , Watson Richard
Published: April 2024

Background:
Inflammation contributes to reperfusion injury, and experimental studies employing anti-inflammatory treatments have shown beneficial effects. RNS60 is a 0.9% NaCl solution containing charged-stabilized nanostructures as a result of mechanical processing in the presence of oxygen. Preclinical in-vitro and in-vivo studies in multiple disease models have demonstrated that RNS60 modulates ion channels and has broad anti-inflammatory and cytoprotective effects.

Objective:
To test the hypothesis that RNS60 will positively influence survival and physiological parameters after myocardial infarction, we conducted a study in the balloon-induced myocardial ischemia/reperfusion (I/R) model in pigs.

Methods:
Male and female domestic pigs (45-50 kg) were subjected to myocardial ischemia by occlusion of the left anterior descending coronary artery for 40 minutes. Groups of males or females (n = 4/group) were treated with RNS60 or normal saline (NS) as control by single intracoronary injection (0.065 mL/kg) at time of reperfusion and by subsequent intravenous injections (100 mL/kg) every 4 hours for 7 days. ECGs were analyzed for T-wave abnormalities including T-elevation, biphasic T-waves and flipped T-waves. Myocardial damage was assessed by measuring circulating levels of troponin and by histologic analysis of the left ventricle for signs of tissue necrosis and inflammatory cell infiltration.

Results:
RNS60 treatment reduced mortality in male pigs (0/4 in RNS60 group vs. 2/4 in NS group) and caused a normalization of ECG tracings both in males and in females. In addition, RNS60 treatment completely prevented the infarct-induced elevation of circulating levels of cardiac troponin in male pigs at 6 (RNS60 1.12±0.36 vs. NS 6.00±3.39 ng/mL), 12 (RNS60 0.71±0.16 vs. NS 16.96±11.05 ng/mL), and 24 hours (RNS60 0.46±0.17 vs. NS 16.41±12.75 ng/mL). Consistent with these findings, the hearts of RNS60-treated male pigs were free of signs of necrosis or mononuclear infiltration at 7 days post I/R.

Conclusion:
Treatment with a saline solution containing CSNs has the potential to reduce I/R injury in vivo.
Abstract 17410: Pre-Treatment with Liposomal 6R-BH4 but not 6S-BH4 Induces in vivo Cardioprotection Through Maintenance of Nitric Oxide Synthase Coupling
Authors: Xie Lin , Talukder M A Hassan , Varadharaj Saradhadevi , Zweier Jay L
Published: April 2024

Tetrahydrobiopterin (BH4) is an essential co-factor for nitric oxide synthase (NOS) activity and BH4 depletion leads to endothelial NOS (eNOS) uncoupling with increased superoxide (O
2

-.

) generation. Myocardial BH4 levels are decreased with ischemia/reperfusion (I/R) and have been hypothesized to play a critical role in modulating eNOS activity and myocardial salvage. BH4 treatment exerts myocardial protection; however, questions remain regarding the related mechanism and role of NOS coupling versus nonspecific antioxidative effects of BH4. To address this issue, rats were subjected to 60-min
in vivo
coronary artery occlusion and varying periods (10-min, 20-min or 24-hr) of reperfusion with or without liposomal 6R-BH4 or 6S-BH4 supplementation (1 mg/kg, iv, 5-min before ischemia). Myocardial NO and O
2

-.

production were measured in frozen heart sections using the fluorescence probes (CuFL and DHE, respectively) in the absence or presence of NOS inhibitor or SOD mimetic. Myocardial infarct size was determined 24-hr after reperfusion and compared with NOS inhibitor (L-NAME) or 6R-BH4 or 6S-BH4 (that lacks NOS co-factor activity). Compared to vehicle group, 6R-BH4 treatment caused an increase in NO with decrease in O
2

-.

in I/R hearts. Postischemic NO or O
2

-.

-derived fluorescence was largely abolished by added NOS inhibitor L-NAME (1 mM) or the SOD-mimetic MnTBAP (50 μM), respectively. 6R-BH4 reduced myocardial infarct size by ∼50% compared to vehicle group (31±2% vs. 59±2%, n=8). L-NAME pre-treatment (10 mg/kg, iv, 15-min before vehicle or 6R-BH4) had no effect on vehicle group, but it abolished the infarct-limiting effect of 6R-BH4 treatment. Compared to vehicle, 6S-BH4 had minimal effect on myocardial infarction (59±2% vs. 50±3%, n=6-8). Thus, these findings demonstrate that the protective effect of BH4 is primarily due to restoration of NOS coupling with suppression of O
2

-.

and enhancement of NO production from the enzyme.
Abstract 17418: Vector Velocity Imaging: A Reliable Tool to Quantify Myocardial Function and Predict Clinical Outcomes in Single Ventricle Patients
Authors: West Shawn C , Saunders Christine H , Duncan Nicole , Jayakumar Kaimal A
Published: April 2024

Background:
Ventricular function is one of the factors that correlate with survival to second stage surgical palliation in single ventricle (SV) patients. Standard 2D echocardiography (2DE) has limitations in evaluating right ventricular function. Myocardial function can be reliably determined using Vector Velocity Imaging (VVI), which is an angle independent method of evaluating myocardial mechanics using conventional 2DE images.

HYPOTHESIS:
VVI provides a valid and reproducible measure of ventricular function in SV patients compared to standard 2DE with direct correlation to clinical outcomes.

Methods:
Medical records and 2DE's were retrospectively reviewed on 72 patients with SV's (37 systemic right ventricles, 35 systemic left ventricles. VVI analysis was performed offline using Siemens Syngo software. When feasible, 2D and Doppler parameters of ventricular function were performed. Using VVI on a 4 chamber image longitudinal velocity (LVel), strain (S), strain rate (SR) were obtained. Ventricular function was measured pre and post stage 1 palliation and compared to normals.

Results:
Fifty seven patients survived to stage 2 palliation (79%). Of the 15 deceased, 10 survived to hospital discharge; 10 had a single RV and 5 had single LV. Heterotaxy, post operative ECMO, sepsis, atrioventricular valve insufficiency and chylothorax were factors associated with death. Using 2DE, ventricular function was qualitatively normal in all but 3 patients pre-stage 1 and in 9 patients post stage 1. Other quantitative parameters were not consistently employed through the study period. LVel, S, and SR were depressed compared to normal hearts in all study patients. There was a statistical difference in the LVel between the survivors and non-survivors (p 0.017).

Conclusions:
Despite qualitatively normal ventricular function, VVI shows significantly decreased myocardial function in both single left and right ventricles when compared to normal hearts. In the absence of traditional quantitative measures of SV function, VVI is a reliable tool to evaluate myocardial mechanics and serves as an adjunct to prognosticate clinical outcomes.
Abstract 17445: NF2 Regulates Mst1 Activation and Ischemia Reperfusion Injury
Authors: Del Re Dominic , Zhai Peiyong , Sadoshima Junichi
Published: April 2024

Neurofibromin 2 (NF2)/merlin is a tumor suppressor that can regulate activation of the hippo pathway in
Drosophila
and the mammalian liver, thereby inhibiting cell growth and promoting apoptosis. We have shown previously that the mammalian homologue of hippo, Mst1, has a similar function in the heart. Therefore, we sought to determine whether NF2 can mediate activation of Mst1 in the heart and modulate cardiac ischemia/reperfusion (I/R) injury. Both NF2 and Mst1 are activated by oxidative stress in isolated cardiomyocytes in vitro and in the heart following I/R. Increased expression of NF2 in cardiomyocytes increased Mst1 phosphorylation (2.9±0.2-fold vs LacZ, p<0.05) and elicited apoptosis (4.8±1.7-fold vs LacZ, p<0.05) that was prevented by co-expression of kinase inactive Mst1 (61±12% decrease vs. NF2, p<0.05). To examine the importance of endogenous NF2 in I/R injury, we employed two different genetic models - systemic heterozygous
nf2
deletion (
nf2
+/-
) and cardiomyocyte-specific disruption using
nf2
floxed mice crossed with αMHC-Cre transgenic mice (
nf2
+/flox
Cre). We performed global I/R (30/60min) injury on isolated perfused hearts using the Langendorff method. Functional parameters and infarct size were determined following the reperfusion phase. While
nf2
+/-
hearts showed no difference in function and infarct size (45±5% vs 48±7%, NS) compared to WT,
nf2
+/flox
Cre hearts had significantly smaller infarcts (22±5% vs 53±8%, p<0.05) and improved function versus
nf2
+/flox
controls.
nf2
+/-
hearts also failed to protect against I/R injury in vivo as Infarct/AAR (34±3% vs 32±2%, NS) and myocyte apoptosis (1.5±0.2% vs 1.7±0.3%, NS) were unchanged despite significant attenuation of Mst1 activation in ventricular homogenates (71±8% reduced vs WT, p<0.05). Preliminary experiments to determine the effect of cardiomyocyte
nf2
deletion show a trend toward protection (Infarct/AAR, 23±6% vs 33±6%, n=4) in
nf2
+/flox
Cre versus nf2
+/flox
control mice. Based on these data we conclude that
nf2
disruption in cardiomyocytes is protective against I/R injury through inhibition of Mst1 activity. However, NF2 signaling in residential non-myocytes appears beneficial for the heart and obscures the detrimental function of NF2 in cardiomyocytes during I/R.
Abstract 17485: Novel Role of NADPH Oxidase Subunit p67
phox
C-terminus Region in Mediation of α
1
-Adrenergic Receptor-Induced Cardiac Hypertrophy
Authors: Zhao Guiqing , Zhang Chongxu , Xu Xianyao , Zhao Qiong , Lambeth J. D , Xiao Lei
Published: April 2024

We previously reported that α
1
-adrenergic receptor (α
1
AR)-induced hypertrophy in adult rat ventricular myocytes (ARVM) was mediated via activation of MEK1/2-ERK1/2 cascade. The hypertrophy was attenuated by NADPH oxidase (NOX) inhibitors and a dominant-negative (DN) mutant (V204A) of NOX subunit p67
phox
that completely inhibits NOX activity of reactive oxygen species (ROS) generation, suggesting the roles of NOX and ROS in α
1
AR signaling. We also showed that cardiac-specific overexpression of this V204A mutant attenuated chronic pressure-overload-induced hypertrophy in transgenic mouse heart. In this study, we further tested the potential ROS-independent role of p67
phox
in α
1
AR signaling using a truncated mutant (1-235) of p67
phox
, which lacks the p67
phox
C-terminus region and is known not affecting NOX activity of ROS generation. Adenoviral constructs containing β-galactosidase (AdLacZ) or p67
phox
mutant 1-235 (Ad235) were expressed in ARVM, and their effects on α
1
AR stimulation (1 μM norepinephrine + 2 μM propranolol)-induced hypertrophy and activation of MEK-ERK cascade was studied. Overexpression of Ad235 significantly attenuated α
1
AR -induced activation of MEK1/2 (58±7% ↓) and ERK1/2 (65±8% ↓) vs. AdLacZ as measured by Western blots. Furthermore, α
1
AR-induced hypertrophy (48 hr) was also prevented by Ad235 as measured by
3
H-leucine incorporation (71±5% ↓) and fetal gene ANF mRNA expression (54±11% ↓) using qRT-PCR. These data confirmed that p67
phox
mediates α
1
AR-induced hypertrophy and MEK1/2-ERK1/2 activation, also suggested an interesting notion that the reported non-ROS generating region of p67
phox
C-terminus may also contribute to α
1
AR-induced hypertrophic signaling in ARVM. In addition, immunoprecipitation of ARVM lysates with anti-p67
phox
antibody followed by Western blotting with anti-ERK or anti-MEK antibodies showed the co-localization of p67
phox
with ERK and MEK kinases, suggesting the direct interaction between MEK-ERK cascade and p67
phox
in ARVM. Taken together, our data showed that the non-ROS generating region of p67
phox
C-terminus mediates α
1
AR-induced hypertrophy in ARVM, suggesting a novel role of p67
phox
as a signaling molecule in α
1
AR-induced hypertrophy via a potential ROS-independent mechanism.
Abstract 17501: Incremental Value of Combined Left Ventricular Volume and Matrix Metalloproteinase-2 for Risk Stratification of Patients with Non-Ischemic Dilated Cardiomyopathy
Authors: Yang Dong Heon , Park Sun Hee , Kim Kyun Hee
Published: April 2024

Background:
Extracellular matrix remodeling and apoptosis are known to play important roles in the progression of heart failure (HF). The aim of this study was to evaluate the prognostic value of serum levels of matrix metalloproteinase(MMP)-2, MMP-3, soluble Fas (sFas) and soluble Fas ligand (sFasL) in patients with non-ischemic dilated cardiomyopathy (DCM).

Methods:
Serum samples were obtained from 70 patients with DCM and analyzed for MMP-2, MMP-3, sFas and sFasL. Patients were followed up for the occurrence of either mortality or hospitalizations due to HF.

Results:
Cardiac events were occurred at 21(30%) patients (death: 10, hospitalization due to HF: 11). LV end-diastolic volume (LVEDV) and end-systolic volume (LVESV) were higher and mitral Ea was lower in cardiac event group. Serum level of MMP-2 was significantly higher in cardiac event group (287.2±99.3 vs 221.0±68.9 ng/mL, p=0.01). However, serum levels of MMP-3, sFas and sFasL were not different between two groups. Kaplan-Meier event free survival curve stratified into 4 groups according to combinations of LVEDV and MMP-2 showed significantly different event rates (Fig 1). Cox proportional hazards analysis demonstrated that MMP-2 added significant incremental prognostic information (Fig 2).

Conclusion:
Serum level of MMP-2, but not MMP-3, sFas or sFasL is an independent prognostic factor and combined LVV and MMP-2 have incremental value to predict cardiac events in patients with DCM.
Abstract 17544: Beta1-Adrenergic Receptor Autoantibodies from Heart Failure Rats Enhanced the Proliferation of T Lymphocytes Largely in PKA-Dependent Fashion
Authors: Du Yunhui , Yan Li , Wang Jin , Quan Lin , Wang Ke , Lv Tingting , Cao Jimin , Liu Huirong
Published: April 2024

Background:
Autoantibody against the second extracellular loop of beta1-adrengic receptor (beta1-AA) not only contributes to the increased susceptibility to heart failure, but also plays a causative role in myocardial remodeling by its sympathomimetic-like effects via binding with the beta1-adrengic receptor. Our previous studies have observed that long-term presence of beta1-AA lead to the myocardial damage with increased ratios of CD4
+
/CD8
+
T lymphocytes. However, whether the beta1-AA could recognize the corresponding receptor, and therefore, interfere with T lymphocytes remains unclear. Using an
in vitro
simulated T lymphocytes activation model, we attempted to explore the role of beta1-AA from an animal model of post-MI heart failure in the proliferation of T lymphocytes.

Methods:
Myocardial infarction was induced in adult male Wistar rats by ligating the left anterior descending coronary artery. Beta1-AA was acquired from sera of rats with heart failure. The CD3
+
T lymphocytes were selected separately through flow cytometry. The expression of beta1-adrengic receptor on the CD3
+
T lymphocytes was detected by confocal microscope, and the proliferation of the CD3
+
T lymphocytes was examined by CCK-8 kits.

Results:
Our results showed that beta1-adrengic receptor is expressed on the surface of CD3
+
T lymphocytes of rats. Meanwhile, beta1-AA from heart failure rats could promote the proliferation of CD3
+
T lymphocytes in
vitro
in a dose-dependent manner (0.115±0.003vs.0.0895±0.005,
P
<0.05; 0.117±0.001 vs. 0.0901±0.006,
P
<0.05; 0.128±0.03 vs.0.0925±0.0007,
P
<0.05), which could be fully blocked by selective beta1-adrengic receptor antagonist metoprolol (0.11±0.0075 vs. 0.0925 ±0.0007,
P
>0.05) and the PKA inhibitor H89 (0.098±0.05 vs. 0.0925±0.0007,
P
>0.05). Furthermore, beta1-AA induced an increase of the cyclic adenosine monophosphate (265±7.5pmol/mL vs. 109±5.8pmol/mL,
P
<0.01) in the CD3
+
T lymphocytes.

Conclusion:
Our present study demonstrated for the first time that beta1-AA from heart failure rat could enhance the proliferation of CD3
+
T lymphocytes, which may contribute to a more comprehensive understanding of the immune effects of beta1-AA on heart failure.
Abstract 17562: Poorer Survival with Insulin Therapy at Discharge in Diabetic Patients with Acute Myocardial Infarction: The FAST-MI Registry
Authors: Puymirat Etienne , Vedrenne Geraldine , Donataccio Maria Pia , Aissaoui Nadia , Machecourt Jacques , Zeller Marianne , Carrie Didier , Ferrìeres Jean , Simon Tabassome , Danchin Nicolas ,   FAST-MI investigators
Published: April 2024

The role of insulin therapy after AMI is debated. We assessed 3-year survival in survivors of AMI with diabetes, according to the prescription of insulin at discharge. All patients were included in the FAST-MI registry, a French nationwide registry of patients with AMI hospitalized in 2005 in 223 institutions.

Of the 1228 diabetic patients, 467 (38%) had insulin at discharge. These were older (70±12 vs 69±12 years, p=0.004), had a higher GRACE risk score (156 ± 33 vs 147 ± 35, p<0.001), higher admission glycemia (232 ± 110 vs 190 ± 85 mg/dL, p<0.001), higher HbA1c (8.1 ± 1.6 vs 7.2 ± 1.4, p<0.001) and longer duration of diabetes (diabetes Hx >10 years: 35% vs 16.5%, p<0.001). Type of MI did not differ (STEMI: 39% vs 44%, p=0.11). Fewer patients in the insulin group had coronary angiography (78% vs 88%, p<0.001) or PCI (53% vs 67%, p<0.001) during the hospital stay. Optimal medical therapy at discharge was prescribed in 51% vs 47% of the patients, respectively (P=0.12). Finally, other antidiabetic medications at discharge were less frequent in the insulin group (metformin: 8% vs 25%, p<0.001; sulfonylureas: 9% vs 36%, p<0.001; glitazones: 0.2% vs 3.4%, p<0.001).

Three-year survival was 66% in insulin-treated versus 80% in patients without insulin (p<0.001). Subgroup analyses confirmed higher mortality in patients with insulin at discharge in both STEMI and NSTEMI patients, in those aged 75 years or less, or in those with or without PCI.

Using Cox multivariate analysis (covariates: age, sex, risk factors, comorbidities, type of AMI, CAD extent, use of PCI, use of CABG, HbA1c and admission glycemia levels, duration of diabetes, in-hospital complications, and other discharge medications), the adjusted HR for 3-year death was 1.56 (1.15-2.10), p=0.004, for patients with insulin at discharge; when treatment with insulin within 48 hours of admission was added to the model, the HR was 1.40 (1.06-1.84), p<0.02. Finally, in propensity score matched cohorts (n=240 in each group), HR for death at 3 years was 1.41 (1.01-1.98), p=0.04 for patients receiving insulin.

Conclusion:
in this real-world nationwide registry, the prescription of insulin at discharge in diabetic patients was associated with poorer long-term survival, even after extensive multivariate adjustment for confounders.