bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 18797: Casein Kinase II (csnk2a2) is Associated With Leucocyte Telomere Shortening and Increased Cardiovascular Disease Risk in Diabetes
Authors: Natt Praveen , Saxena Richa , Dib Patrick , Ralhan Sarju , Wander Gurpreet S , Stowell Donald , Peyton Marvin , Sanghera Dharambir
Published: April 2024

The shorter telomere length has been linked to the pathology of cardiovascular disease (CVD) and type 2 diabetes (T2D), and is widely considered as a marker for biological aging. A genome-wide association scan (GWAS) analysis of shorter leucocyte telomere length (LTL) conducted on 1,616 participants from the Sikh Diabetes Study (SDS) identified 338 top independent signals (p<10-4) to be significantly associated with a shorter LTL independent of T2D. Most promising 48 SNPs were further replicated through genotyping in an additional Punjabi Sikh sample (n=2,397). In combined meta-analysis in the Punjabi Sikh populations (n=4,013/1,946 T2D cases), we identified a novel locus in association with LTL at 16q21 represented by an intronic SNP in the CSNK2A2 (p=4.4x10-8). Our findings also revealed an independent association of shorter LTL with T2D and cardio metabolic risk. The mean LTL showed a gradual decline from healthy subjects to individuals with T2D and CHD with respective mean LTL being 2.10 in healthy, 1.95 in T2D, 1.69 in CHD, and 1.59 in T2D+CHD. Interestingly, the telomeric repeat binding factor 1(TRF1) serves as a substrate for CSNK2A2, which phosphorylates and initiates its binding to telomere. CSNK2A2 also interacts with multiple genes and miRNAs in pathway controlling LTL and CVD. To further understand the functional significance of the genetic variation CSNK2A2 and other genes in association with CHD and telomere replication pathway, we analyzed the expression of 84 miRNA in carotid aortic plaque and muscle tissues obtained from CHD patients who had undergone coronary artery bypass graft (CABG) using miScript miRNA Human CVD arrays (Qiagen, Chatsworth, CA). Our initial analysis revealed a significant difference (p<0.05) in expression of miR208 that regulates CSNK2A2. Additionally, expression of miR155 associated with TERF1 and miR1 associated with TERF2 were down-regulated, and expression of miR185/miR27a/miR183- associated with POT1 was elevated in atherosclerotic plaque compared to muscle. Future functional studies may provide clinically important insights on the interplay between genetic variants in CSNK2A2 and other LTL pathway genes and their interaction with miRNA in atherosclerotic tissues for affecting CVD risk in diabetes.
Abstract 188: Pediatric Medical Emergency Team Response and Outcomes: A Report of 4,181 Events From the AHA Get With the Guidelines®-Resuscitation Registry
Authors: Raymond Tia T , Bonafide Christopher P , Praestgaard Amy , Nadkarni Vinay M , Berg Robert A , Parshuram Chris S , Hunt Elizabeth
Published: April 2024

Background:
In-hospital cardiac arrest (CA) is often preceded by signs and symptoms that predict subsequent deterioration. In response, hospitals created Medical Emergency Teams (METs) to bring skilled resources to the bedside with the aim of improving outcomes.

Objective:
Describe a cohort of pediatric MET events from the AHA Get With the Guidelines-Resuscitation (GWTG-R) registry.

Methods:
We analyzed consecutive pediatric (< 18 yrs) MET events submitted to the AHA GWTG-R from Jan 2006 - Feb 2012. We excluded MET events in outpatient, critical care, newborn nurseries, delivery rooms, emergency departments (ED) and interventional/diagnostic areas.

Results:
We identified 4,181 MET events from 170 U.S. hospitals: median age 3.0 yrs (IQR = 0.0-13.0) with 52% male. Majority of MET events were in general inpatient wards (N = 3136, 75%) and telemetry/step-down units (N = 580, 13%). Medical (71%) and surgical (15%) non-cardiac patients were most frequent. Median length of MET event was 29.0 mins (IQR = 17.0-47.0). Most frequent triggers included: decreased oxygen saturation (30%), difficulty breathing (24%), staff concern (23%), tachypnea (21%), mental status changes (16%), and respiratory depression (12%). Within 24 hrs prior to MET call, 15% were transferred from an ICU, and 22% were admitted from the ED. Frequent non-drug interventions included: oxygen (58%), peripheral IV placement (30%), CXR (16%), suctioning (15%), and ICU consult (12%). Frequent drug interventions included: fluid bolus (21%), inhaled bronchodilators (16%), and anti-epileptics (7%). Almost half were transferred to the ICU (n = 2022, 48%), 236 (6%) progressed to require emergency assisted ventilation, and 18 patients (0.43%) progressed to CA. Survival to discharge was 92% (N = 3789).

Conclusions:
MET events occurred in general inpatient wards for objective indications, included assisted ventilation or CPR in 6.4%, and were associated with 8% hospital mortality. After treatment in 87% of events, 39% remained on inpatient wards, suggesting MET associated treatments may have stabilized or improved the condition of children judged to be clinically deteriorating by ward staff. Frequent events after ED admission or ICU transfer may represent an opportunity to improve the system of care.
Abstract 18804: A Saline Containing Charge-Stabilized Nanostructures Inhibits Apoptosis of Cardiomyocytes Subjected to Ischemia/Reperfusion Injury
Authors: Kalmes Andreas , Anderson-Haley Monica , Ghosh Supurna , Watson Richard
Published: April 2024

Background:
Inflammation and apoptosis contribute to ischemia/reperfusion (I/R) injury after acute myocardial infarction (AMI). RNS60 is an isotonic saline solution containing charged-stabilized nanostructures introduced by Taylor-Couette Poiseuille flow in the presence of an elevated oxygen concentration. RNS60 has shown anti-inflammatory and cytoprotective effects across models of pulmonary and neuro-inflammation and significantly reduced infarct size in a pig model of AMI.

Objective:
To investigate whether RNS60 reduces tissue damage after AMI by effects on cardiomyocyte apoptosis.

Methods:
Groups of male pigs (25-35 kg) were subjected to myocardial ischemia for 60 minutes and treated with RNS60 or normal saline (NS) by single intracoronary injection (0.1 mL/kg) at time of reperfusion and by continuous intravenous infusion (1.0 mL/kg/hour) for 4 days. Apoptosis in the peri-infarct region was quantified by counting the number of caspase 3-positive cells. The expression of proteins of the reperfusion injury salvage kinase pathway was measured by Western blot.

Results:
Ischemia for 60 minutes followed by reperfusion for 4 days caused infarcts measuring 44% 6% of the area at risk in NS-treated animals (n=14). RNS60 treatment reduced the infarct size by 32 % (n=13,
P
<0.001). The number of caspase 3-positive cells in the peri-infarct region was significantly reduced in the RNS60-group (
P
<0.05). At 4 days after reperfusion, the expression of phospho-Akt, Bcl-2, Bcl-xl, and phospho-GSK3 was not different between the groups. Interestingly, however, RNS60 treatment significantly reduced the expression of HSP90 (
P
<0.01), which has recently been linked to a reduction of I/R injury by post-conditioning in pig hearts.

Conclusion:
Treatment with RNS60, a physically modified saline devoid of an active pharmaceutical ingredient, reduces I/R injury in a pig model of AMI, at least in part through inhibition of apoptosis and modulation of the stress protein response in cardiomyocytes. These findings suggest the possibility to develop a new class of therapeutics to limit cardiac damage after coronary revascularization procedures in AMI patients.
Abstract 18817: The Role of Mst1 and Mst2 in Pressure Overload-Induced Hypertrophy and Failure
Authors: Del Re Dominic P , Yamamoto Takanobu , Zhai Peiyong , Sadoshima Junichi
Published: April 2024

Mammalian sterile 20-like kinases 1 and 2 (Mst1/2) are highly conserved and are thought to have similar pro-apoptotic and anti-cell growth properties. Previous work has demonstrated that increased expression of Mst1 causes robust cardiomyocyte apoptosis, heart failure and premature death in mice, yet the function of endogenous Mst1/2 has not been investigated. The goal of this study was to determine the role of Mst1 and Mst2 in the development of heart failure using genetically altered Mst isoform-specific mice. Systemic deletion of both Mst isoforms is embryonic lethal; therefore we utilized mice harboring floxed Mst1 alleles on an Mst2-/- background and bred them with α-MHC Cre mice to disrupt both isoforms in cardiomyocytes (Mst DKO). Animals were subjected to transverse aortic constriction for 4 weeks or sham. Echocardiography was performed prior to intervention and immediately before sacrifice. At 8 weeks of age, no significant differences in the cardiac phenotype were observed between control, Mst1-/-, Mst2-/- or Mst DKO mice. In response to pressure overload (PO), control mice had increased heart weight/tibia length (HW/TL), left ventricle weight/tibia length (LVW/TL) and cardiomyocyte cross-sectional area as expected. Surprisingly, this hypertrophic response was significantly attenuated in Mst1-/- and Mst2-/- mice. Interestingly, Mst DKO mice hypertrophied similar to controls. Apoptosis and fibrosis were increased, and LV ejection fraction (LVEF) was decreased after PO in control mice. Mst1-/- and Mst2-/- mice had attenuated apoptosis and fibrosis; however, LVEF was decreased to levels similar to controls. Interestingly, Mst DKO mice also showed attenuated apoptosis and fibrosis but had significantly worse LVEF compared to control mice. Studies are ongoing to address the mechanism responsible for worsened cardiac function observed in Mst DKO mice despite suppression of fibrosis and apoptosis after PO.
Abstract 18819: Clinical Outcomes Following Implantation of a Centrifugal Flow Left-Ventricular Assist Device and Concomitant Cardiac Valve Procedures
Authors: Milano Carmelo A , Pagani Francis D , Slaughter Mark S , Thinh Pham Duc , Hathaway David R , Najarian Kevin B , Aaronson Keith D
Published: April 2024

Purpose:
Patients undergoing implantation of left ventricular assist devices (LVAD) often undergo concomitant cardiac valve procedures, but the added procedural risk has not been studied in detail. We reviewed patients receiving a centrifugal flow LVAD system in the ADVANCE Bridge to Transplant Trial (BTT) and Continued Access Protocol (CAP) to evaluate the impact of concomitant valve procedures on early outcomes.

Methods:
The ADVANCE BTT and CAP trial enrolled 381 patients (pts) through November 2012. This group was divided into two subgroups: pts who underwent a concomitant valve procedure in addition to LVAD implant (VP) and those who did not undergo a concomitant valve procedure (no VP). Preop characteristics, adverse events and Kaplan-Meier survival were compared for the two groups.

Results:
A total of 19.7% (75/381) of pts underwent VP at the time of LVAD implantation. The most frequent procedure was tricuspid valve repair or replacement, performed in 14.7% of pts, followed by aortic (3.4%), and mitral (2.1%) valve procedures. Patients undergoing a VP were younger and had more recent onset of heart failure. Other pre-implant variables were similar for the two groups. Length of time on cardiopulmonary bypass was increased for VP pts, but mean length of hospital stay did not differ.

Proportions of pts having perioperative tamponade, bleeding, arrhythmias, or strokes were similar. VP pts had more right heart failure (RHF) requiring inotropic therapy (37.3% vs. 22.9%,
P
=0.01); however, there was no difference in RHF requiring RVAD support (2.7% vs. 2.6%,
P
=1.00). Overall Kaplan Meier survival for the two groups was similar, 97.3% VP vs. 98.0% No VP at 30 days and 88.2% VP vs. 90.5% No VP at 6 months (
P
=0.57). Survival was also similar for aortic (N=13) versus tricuspid (N=56) procedures, with 6 month survival 90.0% and 88.5%, respectively (
P
=0.75).

Conclusion:
Tricuspid repair was the most common VP. Increased post-op RHF may have reflected more pre-op right heart dysfunction in this patient subgroup. Overall, the concomitant valve group experienced very good survival, suggesting that VP can be performed at the time of LVAD implant with minimal additional risk.
Abstract 18830: Mitochondrial Suppression Due to Loss of Sirt3 Deacetylase Activity Causes Pulmonary Arterial Hypertension
Authors: PAULIN Roxane , Dromparis Peter , Sutendra Gopinath , Provencher Steeve , Bonnet Sebastien , Michelakis Evangelos D
Published: April 2024

Pulmonary arterial hypertension (PAH) is characterized by suppressed apoptosis in the pulmonary artery (PA) wall, leading to an obstructive vascular remodeling and premature death. The suppressed apoptosis is partly due to suppressed mitochondrial function. Recently PAH patients have been shown to have clinical evidence of insulin resistance. Sirtuin 3 (Sirt3), is a mitochondria-localized deacetylase that regulates mitochondrial function. Loss of Sirt3 activity promotes acetylation and inhibition of many mitochondrial enzymes, resulting in mitochondrial suppression. Loss-of-function polymorphisms in the SIRT3 gene have been associated with metabolic syndrome. We hypothesized that loss of SIRT3 promotes PAH.

In vitro, we used resistance PA smooth muscle cells (PASMC) isolated from WT and KO SIRT3 mice. Normoxic-KO-PASMCs had a global decrease in Kreb’s cycle intermediates (mass spectrometry) and respiration, increased mitochondrial membrane potential and decreased mitochondrial reactive oxygen species compared to WT-PASMCs, mimicking the profile of WT-PASMC exposed to hypoxia. They also had activation of Hif-1a (luciferase activity assays), confirming a “pseudohypoxic” state, increased proliferation (%Ki67) and suppressed apoptosis (%TUNEL). In vivo, compared to WT, Sirt3 KO normoxic mice developed spontaneous PAH (mPAP, 30.9±3.13mmHg vs 14±1.41mmHg) which did not worsen by chronic-hypoxia CH (10% for 3 weeks), associated with right ventricle hypertrophy and significant vascular remodeling. Systemic blood pressures did not differ between groups. In the monocrotaline MCT rat model, intra-tracheal nebulization of Sirt3 adenovirus at day 21-post MCT injection, improved mPAP and vascular remodeling compared to the GFP-only adenovirus treated rats.

We showed for the first time a critical role of SIRT3 in PAH. In a parallel abstract submission (Gurtu et al) we describe increased frequency of a characterized loss-of-function SIRT3 single nucleotide polymorphism in PAH patients. The loss of SIRT3 function causes a mitochondrial suppression perhaps explaining both the anti-apoptotic diathesis in PAH vessels and the extra-pulmonary metabolic abnormalities recently described in these patients.
Abstract 18836: Drug Delivery Strategies Employing Angioplasty Balloons for Treatment of Atherosclerosis
Authors: Su Lee-Chun , Iyer Roshni , Xu Hao , Sundaresan Varsha , Punnakitikashem Primana , Yang Jian , Banerjee Subhash , Nguyen Kytai T
Published: April 2024

Introduction:
Conventional treatments of atherosclerosis including angioplasty and stenting have adverse drawbacks like restenosis and thrombosis. Recent research on drug eluting balloons show that anti-restenotic drugs delivered at the atherosclerotic lesion via angioplasty balloons are eliminated through circulation. Our goal is therefore to provide a sustained and targeted drug release at the diseased site via paclitaxel loaded Urethane doped polyester (UPE) nanoparticles (NPs) eluting balloons.

Materials and Methods:
Paclitaxel-loaded UPE NPs were fabricated and characterized by dynamic light scattering, SEM and TEM. These nanoparticles were coated onto the balloon surface by either Layer by Layer (LbL) electrostatic or hydrogel (acrylic acid) coatings. NP loading was optimized by studying various parameters like incubation saturation and coating efficiency. SEM micrographs were acquired to visualize the coatings and the loaded nanoparticles. Finally, rat arteries were harvested and NP delivery via angioplasty balloons to the arterial lumen
ex vivo
was investigated.

Results and Discussion:
UPE NPs had an average size of 300 nm and zeta potential of -28.5 mV. NP loading reached saturation at 24h and 16h, allowing over 65% and 80% of UPE NPs to be loaded for LbL and hydrogel, respectively. Moreover,
ex vivo
NP retention results revealed that a higher rate of NPs can be delivered to the arterial wall by the hydrogel coating compared to LbL coating. It was also noted that coating materials (LbL and hydrogel coating) and UPE NPs were non-toxic to human vascular endothelial cells.

Conclusion:
Our results conclude that LbL nanoparticle loading, although considered as a well-established procedure, provides a comparatively low loading efficiency and NP transfer than that obtained by the hydrogel technique. However, it is difficult to obtain a uniform hydrogel coating consisting of NPs on the balloon surface. If successful, these techniques can provide a means for delivering drug loaded nanoparticles to the atherosclerotic lesion locally.
Abstract 18842: Left Ventricular Dysfunction Development After Bortezomib Treatment in Patients With Oncologic Diagnoses
Authors: Romero Jorge , Chavez Patricia , Rabinovitz Asaf , Shatzkes Joseph , Caldwell Haven , Valencia Carolina , Garcia Mario
Published: April 2024

Background:
Bortezomib (VELCADE ®) has been considered a milestone in the treatment of myeloma. Within three years of its approval by the Food and Drug Administration, the first case of severe reversible cardiac failure surfaced in 2006.

Objective:
Identify the incidence of left ventricular dysfunction in patients that received bortezomib.

Methods:
We identified 160 patients diagnosed with multiple myeloma, mantle cell lymphoma, plasmocytoma, lymphoma, Waldenstrom’s macroglobulinemia and leukemia, retrospectively. Patients were distributed according to treatment received, in 4 cohorts. Left ventricular dysfunction (LVD) was defined as LVEF<55% by echocardiography. Descriptive analysis was used to identify the incidence of left ventricular dysfunction. CAD evaluation was done by either stress testing or coronary angiogram.

Results:
One hundred and sixty patients were identified and distributed in 4 cohorts, according to the treatment received: bortezomib (n=74); bortezomib and adriamycin (n=27); adriamycin (n=25) and melphalan (n=34). The mean age was 58 ±13 years and at least 54 % (n=87) were males. Patients were followed in a 21-day to 7-year time-frame period. LVD was present in 20% (15/74); 22% (6/27), 28% (7/25) and 18% (6/34) of patients that received bortezomib, bortezomib and adriamycin, adriamycin and melphalan, respectively. Adriamycin was give prior to bortezomib in combined treatment cohort and before melphalan in the last cohort. Of those who developed LVD at least we identified 5 patients who had CAD (2, 1,1 and 1 for each cohort, accordingly).

Conclusion:
Bortezomib may be associated with new onset left ventricular dysfunction when given as first line chemotherapy in the treatment of multiple myeloma, mantle cell lymphoma, plasmocytoma, lymphoma, Waldenstrom’s macroglobulinemia and leukemia. It may also potentiate the cardiotoxicity of Adriamycin when used subsequently.

Figure. Incidence of left ventricular systolic dysfunction.
Abstract 18845: Visual Assessment of the Insular Cortices Using Routine Brain Magnetic Resonance Images in Heart Failure
Authors: Pan Alan , Kumar Rajesh , Macey Paul M , Fonarow Gregg C , Harper Ronald M , Woo Mary A
Published: April 2024

INTRODUCTION:
Heart failure (HF) patients show compromised autonomic control that contributes to increased mortality in the condition. The insular cortices contribute to regulation of the autonomic nervous system, and damage in those regions can contribute to cardiac death by exaggerating sympathetic responses characteristic of HF. Structural brain changes have been reported in the insular cortices using quantitative magnetic resonance imaging (MRI) procedures commonly used in research, but rarely applied in clinical practice. It is unclear whether insular injury can be determined by visual examination using routine MRI clinical procedures in HF. Our aim was to visually examine insular cortices in HF and control subjects to determine if appearance of damage appeared based on quantitative MRI procedures can be identified using routine MRI procedures.

METHODS:
We visually assessed insular brain regions in 17 HF (mean age ± SD, 54.4 ± 8.1 years; BMI, 29.4 ± 5.7 kg/m2; 12 male; LVEF, 0.28 ± 0.07) and 50 control subjects (age, 50.6 ± 7.0 years; BMI, 24.9 ± 4.0 kg/m2; 29 male) using T2-weighted and proton density-weighted images acquired from a 3.0-Tesla MRI scanner. Standardized visual assessment scores of the insular cortices were compared between HF and control groups.

RESULTS:
No significant differences in age or gender appeared between HF and control subjects. Body-mass-indices showed significant differences between HF and control subjects. Significant differences arose in the left insular cortex (HF vs. control; 2.53 ± 1.01 vs. 1.88 ± 0.87; P = 0.003) and right insular cortex (2.53 ± 0.87 vs. 1.76 ± 0.87; P = 0.001) in HF compared to control subjects.

CONCLUSIONS:
Visual assessment of routine MR images can detect insular cortical atrophy in HF patients, and may allow for increased opportunity to evaluate the progression of injury accompanying the enhanced sympathetic drive characteristic of the syndrome.
Abstract 18879: Low Income is Associated With Higher Risk of Cardiovascular Events and Mortality in Community Dwelling, Medicare Eligible, College Educated Older Adults With Background Professional Occupation
Authors: Ahmed Amiya A , Morgan Charity J , Fonarow Gregg C , Patel Kanan , Bittner Vera , Deedwania Prakash , Aronow Wilbert , Filippatos Gerasimos , Anker Stefan , Prabhu Sumanth , Allman Richard M , Ahmed Ali
Published: April 2024

Purpose:
Community-dwelling older adults with low income have been shown to be at a higher risk for incident heart failure (HF) and other cardiovascular (CV) events (Circulation 2011; 124:
A12064
). In the current analysis, we further studied the impact of income in community-dwelling, Medicare-eligible, college-educated older adults with professional occupation.

Methods:
Of the 5795 community-dwelling Medicare-eligible adults ≥65 years old, in the Cardiovascular Health Study (1989-1999), 1404 had college or higher education and a background professional occupation. Of these, 465 (33%) had low income, defined as annual household income <$25,000 (2002 median income for Medicare beneficiaries, $20,400).

Results:
Patients had a mean (±SD) age of 73 (±5) years; 40% were women; and 13% African American. Unadjusted and age-sex-race-adjusted associations of low-income with outcomes during 13 years of follow-up are displayed in the
Table
.

Conclusions:
Nearly one-third of community-dwelling, Medicare-eligible, college-educated older adults with background professional occupation had low income, which was associated with higher risk of incident CV events and deaths. Future studies need to explore underlying mechanisms of these disparities despite Medicare coverage and if this disparity will be attenuated in the future under the new US health care reform law that makes provisions for free preventive care for Medicare beneficiaries.
Abstract 18932: Pka is a Master Regulator of Cardiac Hypertrophy Induced by Pressure Overload
Authors: Zhang Xiaoying M , Tang Mingxin , Ai Xiaojie , Christopher Szeto , Chen Xiongwen
Published: April 2024

Aims:
Under pressure overload, the sympathetic nerve system is activated persistently leading to the overactivation of PKA. Conflicting roles of PKA in PCH have been reported. Also the roles of endogenous PKA inhibitor, PKI, in PCH have not been studied. This study aims to explore the role of PKI/PKA in PCH.

Methods and results:
1. RT PCR and Western blot showed that PKIα and PKIγ were highly expressed in the heart but only the expression of PKIα was reduced by transaortic banding (TAB); TAB induced a significant increases in cardiac PKA activity at 1 week post TAB; 2. An adenovirus containing PKI-GFP and 4 transgenic mouse lines overexpressing PKI-GFP were established. AdPKI-GFP (MOI=100) infection of neonatal ventricular myocytes (NRVMs) was able to completely inhibit PKA activation induced by cAMP in the extract . Two transgenic mouse lines with high (HE) and very low (VLE) expression of PKI-GFP that inhibited maximum PKA activity by 95% and 10% were used; overexpressed PKI-GFP does not inhibit the activity of other kinases; 3. In the VLE PKI-GFP TG hearts, the expression of PKI-GFP was mosaic and isolated GFP- LVMs (3224.6±83.4μm2, n=500, N=5) had significantly larger surface area than GFP+ LVMs (2135.6±127.0μm2, n=500, N=5); 4. TAB for 8 weeks did not change HW/BW (5.0±0.4 vs. 5.1±0.6mg/g BW), myocyte cross-sectional area (CSA: 721.2±25.4 vs. 754.1±37.8μm2), myocardial fibrosis (1.0 ±0.3% vs. 1.1±0.4%) and cardiac fractional shortening (FS: 41.4±2.1% vs. 40.8±1.9%) in PKI HE mice (TAB N=12 vs. Sham N=11) but induced significant increases in HW/BW (8.4±0.9 vs. 5.0±0.6mg/gBW), MCSA (1152.9±108.4 vs. 712.4±65.2μm2, ), myocardial fibrosis (12.5 ±1.6% vs. 0.8±0.1%) and depressed FS (38.4±2.4% vs. 24.1±3.1%) in control (TAB, N=8 vs. Sham, N=10; p<0.05) mice. 5. In cultured NRVMs, PKI-GFP prevented myocyte hypertrophy induced by isoproterenol (ISO), phenylephrine (PE) and angiotensin II, as evidenced by no significant increases in protein synthesis (protein/DNA ratio), myocyte surface area, sarcomere organization in AdPKI-GFP infected myocytes induced by these drugs; 6. PKI-GFP infection in NRVMs prevented the translocation of NFAT3 and HDAC5 induced by ISO and PE but increased ANF.

Conclusions:
PKA is a master regulator of PCH induced by pressure overload.
Abstract 18952: Differential Cardiac Gene Expression at the Time of VAD Placement Differentiates Eventual VAD-Recovery From VAD-Dependence
Authors: McTiernan Charles F , Ramani Ravi , McNamara Dennis , Lemster Bonnie , Bermudez Christian , Kormos Robert , Segura Ana , Vela Deborah , Frazier O.H. , Gorcsan John
Published: April 2024

Introduction:
Only ~5% of Ventricular assist device (VAD) supported end stage heart failure (HF) patients recover enough cardiac function to allow VAD removal. VAD use introduces significant risks, yet it is difficult to identify patients with the greatest recovery potential and who may benefit from VAD removal. The RECOVER trial (
NCT00687856
) seeks novel functional and molecular markers to identify those patients that may recover sufficient cardiac function to allow successful VAD removal.

Hypothesis:
Gene expression analysis of the ventricular core recovered at the time of VAD placement can differentiate those patients who eventually develop VAD-independence (
R)
from those remaining VAD-dependent (
D
).

Methods:
Two groups of VAD-supported patients with non-ischemic HF were studied;
R
group (n=9 patients) and
D
(n=14).
R
group patients (8/9) had >6mo freedom from HF after VAD removal.
R
vs
D
did not differ (p=NS) in age (30.0+-/9 vs 36.4+/-11 yrs); sex (6M/3F vs 10M/4F), pre-VAD EF (18.6+/-4 vs17.6+/-5%) or LVEDD (6.24+/-0.4 vs 6.54 +/- 0.8 cm). RNA was isolated from VAD-implant core and analyzed on Agilent GE60K arrays. After log2-transformation and cyclic LOESS normalization, expression analysis was performed (GeneSpring).

Results:
Uncorrected t-test revealed 302 transcripts that differed between
R
and
D
groups by >1.5 fold (p<0.05). Relative to
D
,
R
had 81 transcripts lower and 220 higher. Euclidean Ward’s clustering (Figure) of 45 transcripts with >1.5X differential expression and p<0.005 segregated most
R
(blue) from
D
(red) patients.

Conclusions:
In a small group of patients, gene expression analysis performed at the time of VAD placement showed potential differences between patients with eventual recovery versus those remaining VAD-dependent. The results may reflect differences in underlying in heart failure severity, and reveal those with potential for functional recovery. More cases will be required to confirm these preliminary observations.
Abstract 18991: A Mir-208-mef2 Axis Drives the Decompensation of Right Ventricular Function in Pulmonary Hypertension
Authors: Paulin Roxane , Sutendra Gopinath , Gurtu Vikram , Dromparis Peter , Michelakis Evangelos D
Published: April 2024

Right Ventricular Failure (RVF) is the major cause of morbidity and mortality in PHT but remains understudied compared to left ventricular failure. The transition from a compensated to decompensated RV occurs much earlier in the RV for unknown reasons. RV and LV have different embryology; the Islet1/Mef2/Hand2 axis is specific for RV formation. Mef2 regulates metabolic, contractile and angiogenic genes critical for RV adaptation to pressure overload. MicroRNAs (miRNAs) have emerged as important determinants of LV development and disease, but little is known about RV miRNAs. We hypothesized that a miRNA-Mef2 axis is important in RV decompensation.

We modeled RVF in the rat monocrotaline (MCT) PAH model in a clinical manner, establishing 3 sequential stages of RV response to PAH (n=6/group): a) normal RV at baseline (NRV, RVSP=38±2mmHg, CO=102±2ml/min and RV/LV+Septum=22±1); b) compensated RV (CRV) 3-4weeks post-MCT when mortality is minimal and cardiac output is stable (RVSP=66±8 mmHg, CO=80±13ml/min, RV/LV+Septum=48±3); c) decompensated RV (DRV) 4-6weeks post-MCT when contractility and cardiac output declines while RV size, ascites and mortality increase rapidly (RVSP=52±2mmHg, CO=67±10ml/min, RV/LV+Septum=58±2).

Using unbiased miRNA arrays (n=9), we found that the levels of the cardiac-specific miRNA miR-208 progressively decreased in CRV and DRV, correlating with RV size increase (r=-0.68, n=20, p<0.001); whereas its expression is known to remain stable in models of LV hypertrophy. The level of the miR-208 target, MED13, increased in DRV. MED13, a subunit of the complex mediator of transcription, activates the repressor NCoR1, which deacetylates Mef2 family members, decreasing their transcriptional activity. NCoR1 expression was increased in DRV, while Mef2 expression was decreased. We infected adult cardiomyocytes isolated from CRV free walls with an adenovirus expressing an anti-miR-208. This was associated with increased MED13 and NCoR1 levels, and decreased Mef2 expression, mimicking the transition to DRV in vivo.

We identified an RV-specific miR-208-Mef2 axis characterizing the transition from CRV to DRV, which may lead to the discovery of much-needed biomarkers and treatments of RVF, for which there are currently no treatments.
Abstract 18996: Swirls and Twirls: Flow Patterns in the Reconstructed Aorta in Single Ventricles - A Cardiac Magnetic Resonance Four-Dimensional Flow Study
Authors: Fogel Mark A , Li Christine , Keller Marc , Whitehead Kevin , Harris Matthew
Published: April 2024

Background:
Flow patterns in the aorta are the result of the interplay of ventricular function and aortic geometry and have been implicated in the development of atherosclerotic disease, aortic dilation and aneurysm formation. It may also lend a clue to inefficient power output of the heart. Previous work from our laboratory has demonstrated decreased power output in pts with single right ventricles (SRV) as compared with single left ventricle pts; this may be partially due to the necessity of aortic reconstruction (recon) in SRV pts. The purpose of this study is to determine the flow patterns in recon.

Methods:
A retrospective review of all SRV pts who underwent cardiac magnetic resonance 4-dimensional phase contrast flow imaging from January 2012 to the present. The phase contrast slab was obtained in the candycane view of the aorta. Post processing was performed using GT Flow.

Results:
A total of 11 SRV pts who underwent recon were found, ages 5.1± 1.8 yrs with cardiac index of 4.8± 1.8 liters/minute/meter
2
; 5 with Fontan and 6 with bidirectional Glenn/HemiFontan. A right handed helix (clockwise when viewed in the direction of flow) was visualized in all pts in the ascending aorta (AAo); in one who had a markedly dilated transverse arch, a secondary helical pattern was created in that region. In pts with a narrowed isthmus (46± 4.3% of AAo diameter), helical flow changed to a left handed helix in the descending aorta (DAo); in those without narrowing (65± 11% of AAo diameter), little helical flow was noted in the DAo (P=0.05).

Conclusion:
SRV undergoing recon demonstrated a right handed helix in the AAo; those with a narrowed isthmus demonstrated a reversal of the helix to a left handed pattern in the DAo while those without narrowing showed little secondary flow. Significant isthmus narrowing alters secondary flow patterns in the DAo. These observations may yield a clue to decreased SRV power output.
Abstract 19048: Clonal Analysis of Cardiac Tissue Formation Reveals Limited Proliferative Capacity of Mature Cardiomyocytes During Development
Authors: Kamran Paniz , Sereti Konstantina Ioanna , Ali Shah R , Subat Ali , Contreras-Trujillo H Humberto , Zhao Peng , Wisniewski Nicholas , Garfinkel Alan , Ardehali Reza
Published: April 2024

Strong evidence supports the ability of the heart to generate new cardiomyocytes during development and in response to injury albeit at a very low rate. However, it still remains unclear whether the newly formed cells originate from cardiac progenitor/stem cells or pre-existing cardiomyocytes capable of proliferation. Identification of the cell populations responsible for new cardiomyocyte formation is imperative towards the development of novel clinical strategies. Herein, we hypothesized that cardiac progenitor cells are the main source of the new cardiomyocytes generated during development while contribution of pre-existing cardiomyocytes is limited. For clonal analysis of cardiomyocyte formation we utilized a stochastic multicolor reporter system called Rainbow that allows random marking of cells with the fluorescent proteins Cerulean (CFP), mOrange or mCherry upon Cre-mediated recombination. Selective labeling of cardiomyocytes was achieved by crossing Rainbow mice αMHC-CreER mice. As control Actin-CreER;Rainbow mice were used where all types of cells can be labeled. Rare recombination events were induced at embryonic day E12.5 and clone formation and expansion were retrospectively analyzed at different time-points from E15.5 to postnatal day P30. To determine at which developmental stage cardiac cells lose their ability to proliferate, recombination was induced at different time-points from early embryonic to postnatal life and analysis was performed at P30. αMHC-CreER;Rainbow hearts exhibited mainly single colored cells randomly distributed within the tissue. A few doublets and some rare four-cell clones were observed. In Actin-CreER;Rainbow mice, we observed clones ranging from two to more than twenty cells. Clone formation and expansion decreased with age. Interestingly we observed clones consisting of more than one cell types indicating the existence of a common progenitor cell. We show that αMHC-positive cardiomyocyte proliferation is limited during development while non-αMHC expressing cells exhibit clonal expansion. Our results suggest a possible contribution of cardiac progenitor cells even during late cardiovascular development.
Abstract 19097: Mutant Gravin Positively Modulates Cardiac Hypertrophy Following Chronic Beta Adrenergic Stimulation
Authors: Diaz Diaz Andrea C , Wijaya Cori , Singh Sonal , McConnell Bradley K
Published: April 2024

Gravin, an A kinase anchoring protein (AKAP), scaffolds protein kinase A (PKA) and other signaling molecules to the β2-adrenergic receptor (AR). Gravin plays a vital role in the desensitization of the β2-AR upon agonist stimulation. The objective of this study was to evaluate whether disruption of PKA/gravin interaction prevents cardiac hypertrophy induced by chronic β-AR stimulation and to correlate ventricular hemodynamics to cardiac hypertrophy. Chronic β-AR stimulation was induced in wild-type (WT) and gravin truncated (t/t) mutant mice with isoproterenol (ISO) (60mg/kg/day for 14 days). Ascorbic acid (AA) was used as control. The heart to body weight (HW/BW) ratio, an indicator of hypertrophy, showed that WT-ISO (5.71±0.28) had a significantly higher ratio as compared to WT-AA (3.86±0.082) whereas there was no significant difference between t/t-ISO (4.88±0.24) and t/t-AA (4.31±0.24) groups. Expression of atrial natriuretic factor - a marker of cardaic hypertrophic - was quantified using RT-qPCR and found to be significantly higher in WT-ISO compared to WT-AA but with no significant difference between the t/t-AA and t/t-ISO groups. Next, in vivo performance was evaluated by pressure volume measurements. dP/dt max, indicative of the left ventricular performance was significantly lower in the WT-ISO (7676±376.1) compared to the WT-AA (10175±640.9) with no significant difference between the t/t-ISO (7021±405.5) and t/t-AA (8857±778.2) groups. Ees, representing a parameter of contractility was significantly decreased in the WT-ISO (3.80±0.43) as compared to the WT-AA (7.36 ±0.96) whereas t/t-AA (8.42±1.92) and t/t-ISO (9.77±1.17) groups exhibited no significant differences. Finally the diastolic performance parameter tau was significantly elevated in WT-ISO (9.02±0.19) as compared to the WT-AA (6.76±0.36) whereas t/t-AA (7.28±0.43) and t/t-ISO (7.67±0.54) groups had similar values. Overall, mutant gravin mice (t/t) were resistant to cardiac hypertrophy and had preserved cardiac hemodynamics in response to chronic β-AR stimulation, as compared to WT mice. The data suggests that modulation of gravin and its interaction with the binding partners may play an important role in the progression of heart failure due to cardiac hypertrophy.
Abstract 19101: Is Stop-Flow Necessary for Efficacious Intracoronary Cell Delivery? Comparison With Nonocclusive Intracoronary Infusion in a Porcine Model
Authors: Tseliou Eleni , Dawkins James , Kanazawa Hideaki , Kreke Michelle , Chowdhury Supurna , Malliaras Konstantinos , Middleton Ryan , Smith Rachel , Marbán Linda , Makkar Raj , Marbán Eduardo
Published: April 2024

Background:
Since the first intracoronary delivery of cells to the heart in 2001, the stop-flow technique has been used by default. A balloon angioplasty catheter is inflated in the target vessel and cells infused via the luminal port. However, the need for balloon occlusion has never been demonstrated.

Objective:
We sought to compare the safety and efficacy of intracoronary delivery of allogeneic cardiosphere derived cells (CDCs) under stop-flow versus nonocclusive intracoronary delivery in a porcine model of myocardial infarction (MI).

Methods:
MI was created by 2.5 hr occlusion of the mid-LAD in adult female Yucatan minipigs. Three weeks later, 12.5M CDCs were intracoronarily infused in the LAD under stop-flow (in 3 3-min occlusions with 3 min rest intervals) or nonocclusive conditions (continuous-flow infusion over 10 min; n=5 in each group). During the course of the study, animals underwent contrast enhanced magnetic resonance imaging at baseline (just before infusion) and 4 weeks post infusion. Left ventricular ejection fraction, scar mass and viable mass were evaluated at both time points.

Results:
No adverse events (arrhythmias, death) were observed during or soon after cell infusion in any of the animals infused. Coronary blood flow evaluated by TIMI grade was TIMI 3 in all animals following completion of infusion. TnI and CK-MB values were within normal range 1 day post-infusion in all animals. One month post-infusion, allogeneic CDCs reduced scar mass in both groups (continuous flow p=0.015 vs. baseline; stop-flow p=0.044). The effects on ejection fraction (p=0.08) and viable mass (p=0.88) were equivalent in the two groups.

Conclusions:
Nonocclusive continuous-flow delivery is equally efficient to stop-flow method as a means of cell delivery to the infarcted myocardium, at least for this particular cell type. The need for stop-flow delivery, while traditional, is therefore questionable.
Abstract 19135: Shh-hippo Signaling Pathway Controls Cardiomyocyte Proliferation
Authors: Singh Bhairab N
Published: April 2024

In contrast to newts and zebrafish, the mammalian heart has limited regenerative potential. Defining the molecular cues controlling cardiac regeneration/cellular proliferation would help construct a blueprint to enhance our understanding of cardiac regeneration in mammals. Here, we demonstrate the essential requirement of sonic hedgehog (Shh) signaling during newt heart regeneration and neonatal cardiomyocyte proliferation. In response to ventricular resection, Shh and its downstream effectors including Ptch1 and Smoothened (Smo) are robustly expressed in the injured region. We find that Shh signaling is required for the proliferation of both epicardial as well as myocardial cell types during the regenerative process. Our data indicate that newt cardiomyocytes undergo dedifferentiation in response to resection injury allowing proliferation, regeneration and restoration of cardiac function. Furthermore, pharmacogical inhibition of Shh signaling results in complete ablation of regeneration and subsequent scar formation. Similar to the newt heart, the activation of Shh signals in cultured neonatal cardiomyocytes (MVCMs) promotes cardiomyocyte proliferation, whereas inhibition results in markedly reduced proliferation. Molecular analyses indicate that activation of Shh signaling increases TAZ (a transcriptional co-activator of Hippo signaling) expression, while inhibition results in its reduction. Interestingly, the intracellular localization of TAZ is not altered upon modulation of Shh signaling. These data suggest that the effect of Shh signals on proliferation is mediated through the TAZ-hippo signaling pathway. Our findings demonstrate that the Shh-Hippo signaling pathways function as a key regulator of cardiomyocyte proliferation and potential targets for cardiac regenerative therapies.
Abstract 19141: Natural History of Tricuspid Annulus and Right Atrial Remodeling in Permanent Atrial Fibrillation
Authors: Luong Christina , Tsang Michael , Gin Kenneth , Jue John , Nair Parvathy , Lee PK , Tsang Teresa S
Published: April 2024

Background:
The natural history of tricuspid annulus and right atrial (RA) remodeling in patients with permanent atrial fibrillation (AF) has not been assessed. We aimed to determine the rate of change in tricuspid annulus diameter and RA volume in patients with permanent AF.

Methods:
This cohort study included 160 patients with a history of permanent AF who had at least 2 transthoracic echocardiograms performed between 2005 and 2010 at Vancouver General Hospital in British Columbia. Patients with structural valve disease at onset, congenital heart disease, and patients with more than mild-moderate tricuspid or mitral regurgitation were excluded from analyses. The tricuspid annulus diameter, defined as the distance between the points of attachment of the anterior and septal tricuspid leaflets from the apical 4-chamber view, was measured during end-systole and end-diastole. Maximal RA size was measured in terms of RA volume using single plane Simspon’s method from 4 chamber view. Linear mixed effects modelling was used in analyzing the changes in measurements over time.

Results:
Of the 160 subjects included in this analysis, 100 were men (62.5%). The mean age at study entry was 74±10 yrs. The median number of echocardiographic studies performed was 3 (range 2 - 6). All 160 patients showed progressive increase in tricuspid annulus diameter over time. There was a significant increase in tricuspid annulus diameter at end-systole and end-diastole over a mean follow up time of 3.2 ± 2.8 years. Respectively, the increase was 0.68 mm/ year, 95% CI

0.232 -1.02, P=0.0027) and end-diastole 0.63 mm/year, 95% CI 0.182-0.93, P=0.0015). Mean RA volume increased from a mean of 39 mL/m2 to 81 mL/m2 for the cohort, or 13 mL/m2 per year, which was significantly greater than the increase in left atrial volume (10 mL/m2 per year, P<0.001).

Conclusions:
Permanent AF was associated with significant increase in tricuspid annulus diameter and RA volume over time. The rate of changes appeared greater on the right side than on the left. How these differential changes relate to the frequent findings of right heart failure in these patients warrant further investigations.
Abstract 19149: Pulmonary Oxidative Stress, Reperfusion Injury and Lung Tissue Damage During Cardiac Surgery: The Outcome of an Experimental Trial in a Porcine Model
Authors: Rahman Ishtiaq , Walker Laura , Chanoit Guillaume , Murison Pamela , Hillier James , Pawade Joya , Dora Kim , Beleznai Timea , Angelini Gianni , Suleiman Saadeh , Ascione Raimondo
Published: April 2024

Background and Objective:
The incidence of pulmonary complications following cardiac surgery remains high and is associated with increased in-hospital mortality and costs. Established surgical practice predominantly regards diverting the pulmonary circulation and deflating the lungs from mechanical ventilator (to facilitate surgical exposure) as a safe approach during the period of cardiopulmonary bypass (CPB) and cardioplegic arrest (CA). In this experimental trial we investigate for the first time the incidence of pulmonary dysfunction, ischemia, oxidative stress, and lung tissue damage associated with cardiac surgery in a porcine experimental model and CPB and CA.

Methods:
Landrace white female pigs (~60kg) were randomised to either median sternotomy alone (Control; n=6) or with CPB (80 minutes) and CA with intermittent antegrade cold blood cardioplegia delivered at 20 minutes intervals (CPB+CA; n=7). Standardised anaesthetic, surgical and perfusion protocols were used in accordance with Home Office Guidance. During CPB the lungs were left deflated as per routine surgical practice. Serial blood samples and lung biopsies were collected at baseline, prior weaning CPB (ischemia), and 1 hour following CPB weaning (recovery). Functional, inflammatory, oxidative, histo-pathological, micro-vascular permeability and apoptosis variables were compared.

Results:
In the CPB+CA group there was marked functional deterioration (respiratory index and alveolar-arterial oxygenation gradients; both p<0.05), significant pulmonary ischemia (reduced ATP/ADP and ATP/AMP ratios; both p<0.05), evidence of lung apoptosis (caspase-3 activity), increased pulmonary micro-vascular leakage (p<0.05) and pulmonary tight junctions fragmentation (immunohistochemistry). None of these findings was observed in the Control group.

Conclusions:
The established practice of cardiac surgery does not protect the lungs during CPB and CA and it is associated with pulmonary dysfunction, ischaemia, apoptosis, and marked lung tissue damage. Novel interventions of lung protection during cardiac surgery are required to minimise these detrimental effects.
Abstract 19154: Maladaptive Autophagy and Necrotic Death of Ventricular Myocytes Induced by p53 is Contingent Upon Mitochondrial Death Gene Bnip3
Authors: Kirshenbaum Lorrie A. , Wang Yan , Gang Hongying , Dhingra Rimpy
Published: April 2024

Myocardial ischemia and angiotensin II activate the tumor suppressor p53 protein, which promotes cell death. Previously, we showed that the Bcl-2 death gene Bnip3 is highly induced during ischemia, where it triggers mitochondrial perturbations resulting in autophagy and cell death. However, whether p53 regulates Bnip3 and autophagy is unknown. Herein, we provide new compelling evidence for a novel signaling axis that commonly links p53 and Bnip3 for autophagy and cell death. p53 overexpression increased endogenous Bnip3 mRNA and protein levels resulting in mitochondrial defects leading to loss of mitochondrial ΔΨm. This was accompanied by an increase in autophagic flux and cell death. Notably, genetic loss of function studies, such as Atg7 knock-down or pharmacological inhibition of autophagy with 3-methyl adenine, suppressed cell death induced by p53-indicating that p53 induces maladaptive autophagy. Our previous work demonstrated that Bnip3 induces mitochondrial defects and autophagic cell death. Conversely, loss of function of Bnip3 in cardiac myocytes or Bnip3-/- mouse embryonic fibroblasts prevented mitochondrial targeting of p53, autophagy, and cell death. To our knowledge, these data provide the first evidence for the dual regulation of autophagy and cell death of cardiac myocytes by p53 that is mutually dependent on and obligatorily linked to Bnip3 gene activation. Hence, our findings may explain more fundamentally, how, autophagy and cell death are dually regulated during cardiac stress conditions where p53 is activated.