bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 16711: Contemporary Treatment and Outcomes of Peripheral Vascular Interventions for Symptomatic Lower Extremity Peripheral Arterial Disease: Insights From the National VA Clinical Assessment, Reporting and Tracking (VA-CART) Program Peripheral Registry
Authors: Tsai Thomas T , Dattilo Philip B , Warner Jeremy , Donaldson Darcy , Virchow Allison , Stanislawski Maggie A , O'Donnell Colin I , Rogers R. Kevin , Shunk Kendrick A , Jones William S , Kinlay Scott , Brilakis Emmanouil S , Klein Andrew P , Casserly Ivan P , Rumsfeld John S
Published: April 2024

Background:
The numbers of peripheral vascular interventions (PVI) have exploded over the last decade. The contemporary indications, treatments and outcomes in clinical practice are not well defined.

Methods:
We studied a convenience sample of 358 patients treated in 33 VA catheterization laboratories between August 2005 and August 2010. Patients were stratified by their PVI indication: Claudication vs. Critical limb ischemia (CLI). Kaplan-Meier curves were constructed and Cox proportional hazards analysis was performed to identify independent predictors of follow-up amputation and mortality.

Results:
The median follow-up was 2.37 years, the mean age was 64.9 +/- 8.7 years, and 97.8% have a history of hypertension. Of the 358 patients, 71 (19.8%) underwent PVI for CLI. The superficial femoral artery was the most common target lesion for both claudicants (41.2%) and CLI patients (46.7%). Self expanding stents (46.7%) were the most common treatment strategy for patients with claudication whereas angioplasty (34.7%) was the most common stand alone treatment in CLI patients. Three year survival for patients treated for claudication versus CLI was 89.4 ± 2.4% and 67.3 ± 7.2% respectively (log-rank p<0.001) (Figure). Independent predictors of follow-up mortality included age (hazard ratio[HR], 1.05; 95% CI, 1.02 to 1.08; P<0.001), diabetes mellitus (HR, 2.52; 95% CI, 1.21 to 5.24; P=0.013), and CLI as an indication (HR, 2.54; 95% CI, 1.36 to 4.75; P=0.004). Three year amputation rates for patients treated for claudication or CLI was 1.7 ± 0.9% and 13.8 ± 4.6% respectively (log-rank p<0.001). CLI was a strong independent predictor of amputation (HR, 10.0; 95% CI, 3.0 to 33.3; P<0.001) (Figure).

Conclusions:
Contemporary follow-up mortality and amputation rates in patients undergoing PVI for critical limb ischemia are high, approaching 1 in every 3 patients for mortality and 1 in every 8 patients needing amputation at 3 years.
Abstract 16746: The Utility of a National Online Weight Reduction Intervention: Experience with “Beat the Holiday Bulge”
Authors: Johnson Caitlin , Rodriguez Fatima , Wang Yun , Foody JoAnne
Published: April 2024

Background:
Novel approaches to the obesity epidemic are required. While the use of online intervention to reduce weight and improve cardiovascular (CV) health, little research has assessed the efficacy of online weight management programs in reducing CV risk factors.

Methods:
A free online weight management program, Beat the Holiday Bulge (BHB), was offered to employees at workplaces nationwide during the holiday season from Nov 1
st
to Jan 31
st
, 2011, to prevent weight gain during the holidays. Rolling enrollment was open from Nov 1
st
to Jan 1
st
, and participants completed a comprehensive health risk assessment (HRA) upon enrollment and participated in a 4-week weight-maintenance program including 4 one-week workshops on exercise, diet, and risk factors for CV disease. Those completing HRA and all four workshops were eligible for prizes.

Results:
From Nov 1
st
to Jan 31
st
, 1,640 participants enrolled in BHB. Most participants were female (83% female vs. 17% male) between ages 46 and 55, followed by those 46-55 (28.9%), 36-45 (23.7%), 56-65 (19.6%), 26-35 (17.3%), 25 and under (5.4%) and 66 and over (3.2%). Among participants, 1,480 completed an HRA. Of those completing an HRA, 31.2% were obese (BMI >30), 21.9% had high cholesterol, 20.7% had hypertension, and 65% do not exercise regularly (< 3 days/week). Of 1640 total participants enrolled, 1600 completed week 1 tasks, 286 completed weeks 1 and 2, 126 completed weeks 1-3 and 67 completed all 4 weeks. From Nov 1
st
- Jan 31
st
, there were a total of 14,369 log-ins (Average 8.8 times per person), and participants lost of a total of 1,132.8 lbs (average 0.69 lbs per person).

Conclusion:
A seasonal online weight-maintenance intervention was successful in not only preventing weight gain but promoting weight loss during the holidays. Women were more likely to participant than men, and most had at least one CV disease risk factor. While nearly all participants completed the first week of tasks and less then 1% completed all four, weight-loss was associated with participation, regardless of completion of tasks. With high rates of CV risk factors in the workforce and growing interest in online wellness programs, our results support online interventions as effective strategies for weight loss and improvement of CV health.
Abstract 16782: Contribution of the Primary Arrhythmia Syndromes to Sudden Cardiac Arrest in the General Population: Prospective, 8-Year Study in a Large US Community
Authors: Panikkath Ragesh , Uy-Evanado Audrey , Reinier Kyndaron , Teodorescu Carmen , Chugh Harpriya , Ayala Jo , Mariani Ronald , Wittwer Lynn , Gunson Karen , Jui Jonathan , Chugh Sumeet S
Published: April 2024

Introduction:
While some estimates are available for the burden of the primary arrhythmia disorders such as long QT syndrome and hypertrophic cardiomyopathy, systematic, prospective evaluations in populations of adequate size are lacking.

Methods:
We evaluated the frequency of SCA due to primary arrhythmia syndromes in an ongoing community-based study of one million residents in the northwestern US (2002-09). Analysis was restricted to cases of SCA (non-survivors plus survivors), age>10 years. We performed a detailed analysis of the available electrocardiograms, pre-mortem medical records as well as post-mortem evaluation.

Results:
A total of 1537 SCD cases enrolled during the study period had adequate information available for analysis. Among patients ≥ 35 years, 44.6% had medically documented significant CAD. While postmortem examination was performed in only 17% of total cases, autopsy findings among that subset and from previous postmortem studies of SCD patients indicate that a large majority (>80%) of the remainder of subjects is also likely to have CAD. However, a primary arrhythmia syndrome was diagnosed or apparent on ECG in 3% of all cases, with frequencies as follows: Hypertrophic cardiomyopathy (n=20; 1.3%), idiopathic VF (n=21; 1.4%), long QT syndrome (n=2; <1%), ECG evidence of Brugada pattern (n=2; <1%) and ARVD (n=1; <1%). No cases were identified as short QT syndrome or catacholaminergic polymorphic ventricular tachycardia.

Conclusions:
Primary arrhythmia syndromes contributed to at least 3% of all SCD cases in this US community. Given the study design, this likely represents the lower limit of prevalence.
Abstract 16787: Impact of Aging on Progenitor Cell Homing for Angiogenesis
Authors: Yu Hong , Xu Qiyuan , Wang Jain'An , Zhou Ming-Sheng , Adi Jennipher , Webster Keith
Published: April 2024

Reduced numbers and activity of circulating progenitor stem cells are associated with aging and have been linked with coronary artery disease. Chemokine stromal cell-derived factor-1 (SDF-1) and its receptor CXCR4 mediate bone marrow cell mobilization, tissue homing and engraftment. We recently reported that calcium regulates CXCR4 expression in combination with SDF-1. We assessed the hypothesis that defective CXCR4 expression develops with aging and disease, which results in less progenitor cell homing to vascular lesion site and inefficient repair. CXCR4 expression and its function were compared between bone marrow cells of
aged
ApoE null mice (ApoE
-/-
) that had been fed with a high-fat, high-cholesterol diet for 6-months and 6-week old
young
ApoE
-/-
mice. We found that CXCR4 surface expression is age-dependent. Age and atherosclerosis correlated with significantly lower surface expression of CXCR4 that was less inducible by calcium. The impaired calcium response was associated with defective calcium influx and was partially recovered by treatment with the calcium ionophore ionomycin. The aged ApoE
-/-
mice fed high fat for 6-months had similar characteristics as the 24-month old wild type mice in defective CXCR4 expression and SDF-1 regulation. Cells from aged, atherogenic ApoE-/- mice also displayed defective homing to SDF-1 and the animals had lower serum and bone marrow levels of SDF-1. We conclude that during the evolution of atherosclerosis in ApoE-/- mice there is a progressively reduction of bone marrow cell CXCR4 expression and function, and reduced serum and bone marrow levels of SDF-1. These changes mute the homing capability of bone marrow cells and may contribute to the progression of atherosclerosis in this model.
Abstract 16790: Positive Inotropic Effects of Acute Intravenous Iloprost in Rats with Chronic Pulmonary Arterial Hypertension
Authors: Zeineh Nabil , Bachman Timothy N , El-Haddad Hazim , Champion Hunter C
Published: April 2024

Introduction:
Pulmonary arterial hypertension (PAH) is a syndrome of increased pulmonary vascular resistance that ultimately leads to right ventricular failure. Supportive management for decompensated RV function in chronic PAH is not very well understood and acute administration of prostacyclins is sometimes considered. While prior studies of inotropic effects of prostacyclins on models of acute pulmonary hypertension have yielded mixed results, evaluation of these effects under conditions of chronic PAH and RV dysfunction have not been reported using invasive hemodynamics. We sought to study the effects of an acute intravenous infusion of iloprost on right ventricular contractility in a rat model of chronic PAH.

Methods:
Ten Sprague-Dawley rats weighing 250-350g were treated with monocrotaline 60mg/kg IP. Six weeks later, baseline hemodynamic assessment was done using pressure-volume measurements using conductance catheterization, and these were repeated 10-15 minutes after IV infusion of iloprost (20
µg/kg
). RV contractility was assessed by the End-systolic pressure volume relationship (ESPVR), and Ees/Ea (RV/PA coupling) were obtained by transient decrease in preload (IVC occlusion). All values are reported as mean ± SEM. Paired and unpaired analysis was performed using Student's t-test.

Results:
Animals had evidence of PAH and RV hypertrophy. RV/LV+septum weight was 0.40 (±0.03). Right ventricular systolic pressure (RVSP) was 39.83 (±1.62) mmHg. Administration of iloprost demonstrated a significant increase in the slope of the ESPVR from 0.29 (±0.02) to 0.42 (±0.05) (p<0.05), and ventricular-arterial coupling index Ees/Ea increased from 0.63 (±0.07) to 0.82 (±0.06) (p<0.05). RV contractility index (max dP/dt normalized for instantaneous pressure) increased from 94.11/s to 114.5/s (p<0.05) as did RV ejection fraction from 48.0% to 52.5% (p<0.05). Pulmonary vascular resistance decreased from 0. 50 (±0.05) to 0.33 (±0.05) Wood units (p<0.05).

Conclusion:
Our present study suggests a positive inotropic effect of iloprost (as evidenced by RV contractility index and ESPVR on remodeled right ventricles resulting from chronic PAH. The role of prostacyclins in the acute treatment algorithm of PAH merits further study.
Abstract 16836: Pioglitazone Reduces Angiogenesis by Altering Mitochondrial Function and Reducing Hypoxia Inducible Factor-1 Activation
Authors: Dromparis Peter , Sutendra Gopinath , Bowers Lyndsay , Haromy Alois , Hashimoto Kyoko , Stenson Trevor H , Proctor Spencer , Michelakis Evangelos D , McMurtry Michael S
Published: April 2024

Introduction:
Thiazolidinediones (TZDs) used in type II diabetes are linked with adverse cardiovascular events by an unknown mechanism, including lower extremity revascularization. TZDs can affect mitochondria, which are oxygen sensors and therefore could regulate the angiogenic transcription factor hypoxia inducible factor 1 (HIF1) via mitochondrial derived α-ketoglutarate (αKG) and reactive oxygen species (mROS). We hypothesized that pioglitazone (PIO), a TZD, may impair angiogenesis through a mitochondrial-HIF1 dependent mechanism.

Methods/Results:
Human skeletal myocytes (hSMC) cultured at pO2 120 vs. 40 mmHg were treated with PIO (20 μ g/ml) for 24h. Compared to vehicle, PIO depolarized mitochondria, increased mROS and αKG in hypoxic hSMCs. PIO decreased HIF1 activity (nuclear translocation and decreased VEGF, a HIF1 regulated gene). In vitro, using a matrigel assay, PIO directly inhibited human microvascular endothelial cell (hMVEC) angiogenesis (tubule formation). To assess the paracrine effects and exclude the direct PIO effects on hMVEC, we used a Boyden chamber matrigel bioassay where hSMCs and hMVEC were separated by a cell impermeable membrane. Pre-treatment of hypoxic hSMCs with PIO had less angiogenesis than with vehicle. In vivo, neovascularization was assessed in diabetic (JCR:LP; n=20) and non-diabetic (SD; n= 22) rats. Hindlimb ischemia was induced, and the rats were treated with a clinically relevant PIO dose (10mg/kg/day) or placebo for 14 days. Ischemic hindlimb (gastrocnemius) perfusion was decreased in PIO treated animals (contrast enhanced ultrasound and Tc99m sestamibi micro CT-SPECT), which correlated with decreased angiogenesis (von Willebrand factor and lectin) in both diabetic and non-diabetic models.

Conclusions:
PIO alters mitochondrial function in hSMC, reducing HIF1 activation and inhibiting both paracrine/autocrine angiogenesis. PIO also impaired angiogenesis in diabetic and non-diabetic rats. Impairment of angiogenesis is undesirable in human diabetics with concomitant atherosclerotic vascular disease, and may be a mechanism for adverse effects of TZDs.
Abstract 16839: GLUT-12: A Novel Insulin-Sensitive Glucose Transporter in the Heart?
Authors: Waller Amanda , Kalyanasundaram Anuradha , Periasamy Muthu , Lacombe Veronique A
Published: April 2024

The heart is one of the main organs to utilize glucose. Glucose uptake from the bloodstream, the rate-limiting step in whole body glucose utilization, is regulated by a family of membrane proteins called glucose transporters (GLUTs). Although GLUT4 is the predominant isoform in insulin-sensitive tissues, there is recent evidence that GLUT12 could be a novel second insulin-sensitive GLUT in skeletal muscle. However, its role in the heart is not known, as well as the regulation of insulin-stimulated myocardial GLUT12 trafficking to the cell surface. Finally, despite intensive research, the pathogenic cause of altered glucose transport observed during diabetes remains elusive, and the role of GLUT12 has never been investigated in the diabetic myocardium. Thus, we hypothesized that, as for GLUT4, insulin will regulate GLUT12 translocation to the myocardial cell surface, which will be impaired during diabetes. To test our hypothesis, mice were made diabetic (insulin deficient) by streptozotocin injection and compared to their respective healthy littermates (n=9-12/group). Active cell surface GLUT (4 & 12) content was quantified by a biotinylated photolabeled assay in the intact perfused myocardium (with or without insulin stimulation). To our knowledge, we are the first to apply this technique to GLUT12. Total GLUT (4 & 12) protein expression and Akt substrate of 160 kDa (AS160, the most distal signaling protein implicated in GLUT trafficking) were measured by Western blot. Insulin stimulation significantly increased translocation of GLUT-4, but not -12, in the heart of healthy mice. Active cell surface GLUT12 was significantly increased in the diabetic myocardium, potentially as a compensatory mechanism for the observed downregulation of active GLUT4. Total cardiac GLUT4 content, but not GLUT12, was decreased during diabetes. Changes in GLUT trafficking were not associated with alterations in total or phosphorylated AS160, suggesting that AS160 is not a major pathogenic factor in the heart during insulin-dependent diabetes. Overall our data suggest that, in contrast to GLUT4, the insulin-signaling pathway does not mediate myocardial translocation of GLUT12. Thus, in the heart, GLUT12 may function as a basal GLUT located primarily at the cell surface.
Abstract 16850: The Impact of Coxsackievirus Infection on Cardiac Stem Cells and Postnatal Heart Development
Authors: Sin Jon , Tabor-Godwin Jenna , Feuer Ralph , Gottlieb Roberta
Published: April 2024

Coxsackievirus B (CVB) is an enterovirus that most commonly causes a self-limited febrile illness in young children, but in severe cases it can progress to myocarditis or meningo-encephalitis. The long-term consequences of mild CVB infection are unknown, although CVB antibodies are encountered more frequently in patients with heart failure than in the general population, raising the possibility that this cardiotropic virus could have lasting sequelae even in subclinical infection. Previously we described a mouse model in which early postnatal exposure to doxorubicin depleted c-Kit+ cardiac stem cells (CSCs) and resulted in cardiac dysfunction in adult animals that could only be elicited by a prolonged exercise challenge or experimentally induced myocardial infarction. We and others have shown that CVB infects actively proliferating neural stem cells and induces cell death. In this study, we report that cultured CSCs isolated from neonatal mouse hearts were also susceptible to cytopathic CVB infection. To test the hypothesis that CVB infection might deplete the CSC population in the heart during self-limited infection, we inoculated neonatal BALB/c mice with recombinant CVB expressing eGFP and assessed the effects of viral infection on CSCs. We observed infected CSCs in cardiac tissue as well as a 50% reduction in the number of c-Kit+ cells in adult animals. Our observations indicate that CVB can target CSCs in the neonatal heart, infecting them and triggering their destruction. Similar to our findings in the doxorubicin late-onset heart failure model, we suggest that the loss of CSCs during subclinical CVB infection in early childhood may predispose to late-onset heart failure. Further work is needed to demonstrate the cardiovascular consequences of CSC infection and depletion after neonatal CVB infection.
Abstract 16851: Estradiol-Treated Cardiac Stem Cells Improve Myocardial Recovery Following Acute Ischemia/Reperfusion Through Enhanced Paracrine Protection
Authors: Huang Chunyan , Gu Hongmei , Manukyan Mariuxi , Wang Meijing
Published: April 2024

INTRODUCTION:
Cardiac stem cells (CSC) mediate cardioprotection following ischemia. However, prior research has mainly focused on studying differentiation capacities of CSC. Little is known about implication of paracrine action by CSC in protection of the ischemic heart. On the other hand, our group and others have shown that non-cardiac stem cells mediate their beneficial effects primarily via paracrine action and estrogen is implicated in promoting this stem cell-mediated protection. In this study, therefore, we hypothesized that 1) CSC are able to acutely improve cardiac function without cell differentiation following ischemia/reperfusion (I/R) and 2) 17β-estradiol (E2)-treated CSC provide greater protection of cardiac function.

METHOD:
CSC were isolated from C57BL mouse hearts, and identified by flow cytometry and mRNA-qPCR. Cardiac I/R was performed in isolated mouse hearts via Langendorff. 0.1x10^6/ml CSC or E2-treated CSC (CSC treated with 100nM of E2 for 24-hr) were infused immediately prior to ischemia. Secretion of VEGF, HGF and SDF-1 by CSC and E2-treated CSC was assessed using ELISA. Hypoxia-induced myocyte injury was detected by LDH assay. Data were analyzed with two-way ANOVA or t-test, p<0.05=statistically significant.

RESULTS:
Flow cytometry data revealed that CSC expressed Sca-1, CD29 and CD44 (all >90%), but did not express CD31, CD34, CD45 or CD106 (all <5%). Cardiac specific transcription factors NKX2.5, Gata4, MEF2c and Tbx5 were detected in CSC. E2-treated CSC produced higher levels of VEGF, HGF and SDF-1 compared to untreated CSC. Infusion of CSC and E2-treated CSC improved myocardial function following acute I/R with greater protection in E2-treated CSC group (graph).

CONCLUSION:
Pretreatment of CSC acutely improved I/R-injured cardiac function and myocyte viability through paracrine action. E2-treated CSC may enhance this paracrine protection, suggesting that in vitro modification of CSC may improve therapeutic outcome.
Abstract 16861: Reduction in Inappropriate Utilization of Myocardial Perfusion SPECT, Stress Echocardiography, and Coronary CT Angiography Using a Point-of-Order Automated Decision Support Tool: The Prospective Multicenter ENCOURAGE study
Authors: Lin Fay Y , Gebow Dan , Labounty Troy M , Gomez Millie J , Dunning Allison M , Shaw Leslee J , Min James K
Published: April 2024

Background.
The appropriate use rates for myocardial perfusion SPECT (MPS), stress echocardiography (STE) and coronary CT angiography (CCTA) in the community are unknown.

Methods.
We prospectively collected American College of Cardiology appropriate use criteria (AUC) ratings on consecutive MPS, STE and CCTA studies among single specialty cardiology practices in one large metro area that submitted claims to United Health Care. Physician groups used online appropriate use decision support tools for determination of appropriateness.

Results.
4 physician groups comprised of 101 cardiologists rated indications for 612 patients over 8 months (43±25 years, 35% female, 18% diabetic, 40% prior CAD). Imaging studies comprised 431 (70%) MPS, 152 (25%) STE and 29 (5%) CCTA. On average, it took 133+322 seconds to obtain an appropriate use rating using the calculator. Appropriate studies constituted 56%, 47%, and 52% of all MPS, STE and CCTA respectively, while indications not covered by AUC guidelines constituted 7%, 18% and 17% respectively. There were no significant differences in the proportions of appropriate, uncertain, inappropriate and non-addressed indications by MPS, STE or CCTA (p=0.16). There was a secular trend towards decreased inappropriate studies over time (23% in 1st quarter vs 11% in last (4th) quarter, p = 0.002)

Conclusion.
In a consecutive cohort of imaging studies in a large metro area, the distribution of appropriateness ratings does not differ significantly between modalities. An appropriate use decision support tool reduces inappropriate testing over time.
Abstract 16870: Myocardial Enhancement on 320 Detector-Row CT Acquired Immediately after PCI in Patients with Acute Myocardial Infarction: Comparison with Contrast Enhanced CMR in Acute and Chronic States
Authors: Nakajima Hiroshi , Kitagawa Kakuya , Onishi Katsuya , Miyagi Hideki , Nakamori Shiro , Kato Shingo , Nagata Motonori , Tanigawa Takashi , Nakamura Mashio , Sakuma Hajime , Ito Masaaki
Published: April 2024

Background:
Identification of irreversibly injured myocardium early after percutaneous coronary intervention (PCI) is important for optimizing management in patients with acute myocardial infarction (AMI). Myocardial CT acquired immediately after PCI is an emerging method that permits viability assessment without additional injection of iodine contrast medium in CT room. The purpose of this study was to determine the relation between CT late enhancement and contrast enhanced CMR findings in acute and chronic states.

Methods:
Fifteen consecutive patients with AMI (59±12 years, 13men) underwent 320 slice MDCT immediately after PCI (peak CK 2295±1309). All patients achieved TIMI flow grade 3 after PCI. CMR studies were performed in acute phase (6.5±3.9 days) and chronic phase(7.3±1.4 months) in all patients. Rest perfusion MRI, late gadolinium enhancement (LGE) MRI and displacement encoded (DENSE) MRI were performed by using a 1.5T MR imager with 32-ch coil. CT-LE, CMR microvascular obstruction (MO) in acute state, CMR-LGE and myocardial strain in acute and chronic states were determined by using a 16-segments model. Transmural lesion was defined as the segment with transmural extent of >50%

Results:
CT-LE was observed in 77 (32.1%) of 240 segments (transmural extent 1-25%;n=9, 26-50%;n=36, 51-75%;n=5, 76-100%;n=27). On CMR obtained in acute state, CMR-LGE and CMR MO was observed in 137 (57.1%) and 31 (12.9%) segments, respectively. CMR LGE was found in 129 (53.8%) segments in chronic state. The area under the receiver operating characteristics curve (AUC) of transmural extent of CT-LE for predicting CMR-MO was 0.824. These values were 0.813 for transmural CMR-LGE in acute phase and 0.754 for transmural CMR-LGE in chronic phase (p<0.001, respectively). In the segments with transmural CT-LE, myocardial radial strain determined by DENSE MRI was more severely impaired (p<0.001) in comparison with other segments.

Conclusion:
CT-LE on MDCT acquired immediately after primary PCI was closely associated with MO and transmural LGE on CMR in acute state, and indicates poor functional recovery in chronic state. CT-LE can provide valuable information regarding regional myocardial damage and viability in AMI patients after PCI.
Abstract 16924: Multimodality Imaging Reveals Decreased Creatine-Kinase Flux and Systolic Strain in Patients with Hypertrophic Cardiomyopathy and Preserved LVEF
Authors: Abraham M Roselle R , Bottomley Paul , Dimaano Veronica L , Pinheiro Aurelio , Traill Thomas , Abraham Theodore P , Weiss Robert
Published: April 2024

Background/Objectives:
We investigated
in vivo
cardiac creatine kinase (CK) ATP supply and function in a family with HCM who carry an extensively characterized point mutation (R403Q) in the cardiac β-myosin heavy chain gene.

Methods:
Quantitative phosphorus (
31
P) saturation transfer MRS was used to noninvasively measure cardiac CK energy transfer-the forward CK flux and the CK rate constant,

k
f

-and CK metabolite concentrations (phosphocreatine, [PCr], and [ATP]) in patients with HCM (n=10), and in age-matched healthy controls (n=15). Systolic strain, LV ejection fraction (EF), diastolic function and cardiac morphology were assessed by echocardiography in HCM patients (n=11) and a second group of healthy controls (n=10).

Results:
LV mass was higher in HCM patients than controls (307.21 ± 12.37 vs 167.63 ± 42.53; p=0.0037). [PCr] was significantly decreased by 22% in HCM patients (7.36 ± 2.29µmol/g wet weight) as compared to controls (9.41 ± 1.2µmol/g; p=0.005), but PCr/ATP ratio was not significantly altered (1.54 ± 0.4 in HCM vs. 1.69 ± 0.29, p=0.26). The pseudo-first-order rate-constant for the CK reaction,
k
f
was reduced by 26% (0.266 ± 0.14 vs. 0.36 ± 0.08, p<0.04) and the forward CK flux was reduced by 43% (1.94 ± 1.27 vs 3.39 ± 0.96, p<0.003) in HCM patients when compared to controls. Diastolic function (E/A) was impaired (0.90 ± 0.31 in HCM vs 1.48 ± 0.27 controls; p=0.0003) and peak systolic strain (longitudinal; εL) was significantly decreased in HCM patients (-13.40 ± 5.32 vs -18.93 ± 2.46; p=0.0076). Peak longitudinal strain and diastolic function (E/A) correlated with NYHA class (R²=0.50;
p
=0.0007); E/A <1 correlated with NYHA class progression over 5 years of follow up (R
2
=0.6, p=0.024).

Conclusions:
PCr,
k
for
and CK flux are significantly reduced in patients compared to age-matched healthy control subjects, indicating impaired CK ATP energy supply even at rest, consistent with prior work on a HCM (R403Q) mouse model. However, only systolic strain and diastolic function were correlated with NYHA class and progression respectively, suggesting that while bioenergetic alterations are associated with the underlying mutation, other downstream molecular effects contribute to the severity of dysfunction and clinical status of these patients.
Abstract 16935: Transferring Ischemia-Resistant Phenotype From Stem Cells into Mouse Hearts by microRNA
Authors: Yin Chang , Salloum Fadi N , Hoke Nicholas N , Kukreja Rakesh C
Published: April 2024

INTRODUCTION:
It was observed that adipose stem cells (ASC) are more resistant to ischemic injury than adult cardiomyocytes. We hypothesized that introducing microRNA (miRNA) pool extracted from ASC (miRNA-ASC) into mouse hearts transfer ASC's ischemia-resistant phenotype and reduce myocardial infarct size following ischemia/reperfusion injury.

METHODS:
CD-1 mice were treated with either miRNA-ASC (2 µg per heart) or volume-matched PBS (30 µl) through direct, multi-site cardiac injection. Twenty-four hours later, both groups were subjected to 30 min of ischemia by coronary artery occlusion and 24 hrs of reperfusion (I/R). Infarct size was measured by tetrazolium staining at the end of I/R. miRNA profiling was performed using microarray technique and verified by q-PCR. Potential targets of miRNA-ASC were studied by q-PCR and Western blot.

RESULTS:
miRNA-ASC reproduced stem cells’ ischemia-resistant phenotype in the recipient mouse hearts, showing a much smaller infarct size (24.2±1.6%; 44% reduction) versus the PBS group (43.5±2.1%; n=6, p<0.05). The miRNA profile of ASC showed that miRNA-21, a predominant and cardioprotective miRNA, was 3.7-folds more (microarray, n=3, p<0.01) or 7.8-folds more (RT-PCR, n=3, p<0.001) than in wild type mouse hearts. More importantly, mRNA of the pro-apoptotic PDCD-4 (programmed cell death 4), a target of miRNA-21, was suppressed by 39.3% (n=3, p<0.01) in the miRNA-ASC treated group, as compared to the PBS group. Interestingly, mRNA of PDCD-4 was not detected in the stem cells. Immunohistochemistry data further confirmed that PDCD-4 positive cells were 77.1% less in the miRNA-ASC treated group versus the PBS group (n=3, p<0.001). The suppression of both mRNA and protein of PDCD-4 in the miRNA-ASC group may contribute to the observed ischemia-resistant phenotype transferred into the hearts.

CONCLUSION:
miRNA-ASC is capable of carrying the stem cells’ ischemia-resistant attribute into the recipient hearts and reduces infarct size following ischemia/reperfusion. This property of miRNA-ASC may be explored and used as a molecular tool against I/R injury, a new approach to traditional cellular therapy of stem cells.
Abstract 16940: Heart Transplant After Failed Single Ventricle Palliation in Young Infants Carries Excess Mortality Risk: A Multi-Institutional Study
Authors: Everitt Melanie D , Boyle Gerard , Schechtman Kenneth B , Zheng Jie , Kaza Aditya K , Bullock Emily A , Dipchand Anne I , Naftel David C , Kirklin James K , Canter Charles E
Published: April 2024

BACKGROUND:
Infant heart transplant (HT) recipients have the best long term survival of any age group, but small donor pool and high early mortality limit the therapeutic efficacy. We aimed to determine the relationship between pre-HT diagnosis and early HT outcome to identify infants most likely to benefit from HT.

METHODS:
The Pediatric Heart Transplant Study (PHTS) database was used to identify 739 infants s/p HT at age ≤6 mths between 1993-2008 divided into the following etiologic groups: cardiomyopathy (CM: 132, 18%); hypoplastic left heart syndrome without prior surgery (HLHS_WOS: 303, 41%); HLHS with surgery (HLHS_WS: 69, 9%); other congenital heart disease without surgery (CHD_WOS: 121, 16%; and other congenital heart disease with surgery (CHD_WS: 114, 15%). Severity of illness at HT, post HT survival, and era effects were compared among the 4 groups.

RESULTS:
The 1 yr survival for HLHS_WOS (79%) was similar to CHD_WOS (79%) and CHD_WS (82%) but worse than CM (89%). HLHS_WS had the highest mortality w 1 yr survival of 70%, p=0.03. Hazard function analysis showed the difference occurred within the 1st 6 mths after HT. Survival remained poor in the current surgical era for HLHS_WS, 71% (1993-1998) v 70% (1999-2008). Risk factors at HT associated w mortality included age <1 mth (OR 2.5; CI 1.3-4.7, p=0.01), ECMO (OR 3.7; CI 2-6.8, p<0.01), ventilator use (OR 1.8; CI 1-3.2, p=0.04), and HLHS_WS (OR 2.3; CI 1.3-4.1, p<0.01). After adjusting for illness severity, differences in mortality risk persisted across etiologic groups. HLHS_WS (HR 2.3, CI 1.3-4, P<0.01), CHD_WOS (HR 1.8, 1.1-3.1, P= 0.03), and HLHS_WOS (HR 1.7, 1.1-2.8, P=0.02) had significantly higher risk for mortality compared to CM.

CONCLUSIONS:
Infant HT recipients with different pre-HT diagnoses have strikingly different outcomes after HT that are unchanged over time and seem unrelated to clinical acuity at HT. CM infants have excellent survival, but HLHS_WS represent a high risk group for early mortality after HT.
Abstract 16946: Induced Pluripotent Stem Cell Derived cKit
Low
Sca1
High
Flk
High
Progenitor Cells Undergo Angiomyogenic Differentiation in the Infarcted Heart and Preserve Global Heart Function
Authors: Afzal Muhammad Z , Haider Khawaja H , Ahmed Rafeeq P , Jiang Shujia , Lai Vien K , Ashraf Muhammad
Published: April 2024

Background:
We have previously established that induced pluripotent stem (iPS) cells spontaneously differentiate into beating cardiomyocytes. The present study was designed to identify cardiac progenitor cell (PCs) population in iPS cells and determine their cellular and molecular characteristics and myocardial regenerative potential.

Methods and Results:
PCs were sorted from day-5 embryoid bodies (EBs) on flow cytometer. Surface marker analysis showed that PCs were cKit
low
Sca1
high
Flk
high
besides positivity for Nkx2.5 and GATA4. When exposed to 1% hypoxia for 24 hours, PCs showed significant increase in gene expression of proangiogenic and cardiomyogenic factors like VEGF, Flt-1, Angiopoietin-1, vWF, and Nkx2.5 as compared to the cells cultured under normoxia. VEGF secretion in the conditioned medium from PCs cultured under hypoxia was 290 pg/ml (
p
<0.01
vs
cells under normoxia, 126pg/ml) and showed enhanced
in vitro
angiogenic potential as determined by tube formation assay (39.8±1.9,
p
<0.01
vs
control) and cell invasion assay (220.5±1.8;
p
<0.01
vs
control) using rat aortic endothelial cells. For
in vivo
determination of cardiogenic potential of PCs, 20µl DMEM without cells (group1, n=6) or containing 5.0x10
5
male cKit
low
Sca1
high
Flk
high
PCs labeled with PKH26 and cultured under normoxia (group2, n=8) or 1% hypoxia for 24 hours (group3, n=8) were injected intramyocardially in a female mouse model of acute coronary artery ligation. Real time PCR on day7 for
Sry
gene (n=4/group) showed higher survival in group-3 (
p
<0.05
vs
group-2). Echocardiography at 4 weeks after cell transplantation, significant improvement in global heart function was observed in group-3 (LVEF =55.9%, LVFS =21%;
p
<0.05
vs
group-2). Fluorescence immunostaining of the histological sections for myogenic and endothelial cell specific markers showed cardiac differentiation and increased blood vessel density in group-3 at 40x (
p
<0.01
vs
group-2).

Conclusions:
iPS cell-derived PCs comprise a multipotent precursor population capable of repopulating the infarcted heart to preserve global cardiac function.
Abstract 16962: Angiotensin II Limits NO Production by Upregulating Arginase through a Mitogen Activated Protein Kinase-Activating Transcription Factor-2 pathway
Authors: Shatanawi Alia , Alkilany Alaaldin M , Caldwell Ruth B , Caldwell R. William
Published: April 2024

Nitric oxide (NO) produced by endothelial nitric oxide synthase (NOS) is needed for normal vascular function. During hypertension, diabetes or aging, elevated levels of arginase (ARG) can compete with NOS for available L-arginine thus reducing vascular NO production. Elevated angiotensin II (Ang II) is a key participant of endothelial dysfunction in many cardiovascular diseases and has been linked to elevated ARG activity. In this study we explored the signaling pathway leading to increased ARG expression/activity in responses to Ang II in bovine aortic endothelial cells (BAEC). Treatment of BAEC with Ang II (10
-7
M, 24 hrs) caused a 40±6% increase (p<0.05) in ARG activity. This was accompanied by 30±8% decrease (p<0.05) in NO production. Our studies indicate involvement of p38 mitogen activated protein kinase (MAPK) in Ang II-induced ARG upregulation and reduced NO production as p38 MAPK inhibitor SB202190 (2 μM) prevented the Ang II-induced increase in ARG activity. Our mouse studies also show involvement of p38 MAPK in Ang II-induced vascular dysfunction associated with elevated ARG activity and ARG expression. Ang II (42 µg/kg/h, sc, 2 wks) caused impaired EC-dependent vasorelaxation in mouse aorta (55±7% vs. 75±8% for control). This impairment was prevented by treatment with p38 inhibitor SB203580 (5µg/kg/day). Ang II also caused a 6.2 fold increase in vascular ARG activity/expression that was completely prevented by p38 MAPK inhibition. Additionally, treatment of BAEC with Ang II causes phosphorylation of activating transcription factor-2 (ATF-2) by 10 minutes with a peak at 30 minutes (3.9 fold). Transfection of BAEC with ATF-2 siRNA prevents Ang II-induced increases in ARG activity/expression and maintains NO production. These results indicate that ATF-2 is necessary for enhanced expression of ARG by Ang II. Collectively our results indicate that Ang II increases endothelial ARG activity/expression through a p38 MAPK-ATF-2 pathway leading to reduced NO production and endothelial dysfunction. Targeting these signaling steps might be therapeutic points for preventing vascular endothelial dysfunction associated with elevated ARG activity/expression.
Abstract 16978: Midregional Pro-Atrial Natriuretic Peptide and Risk of Recurrent Cardiovascular Disease Events in Patients with Stable Coronary Heart Disease Followed Over 8 Years
Authors: Karakas Mahir , Koenig Wolfgang , Kleiner Andrea , Brenner Hermann , Rothenbacher Dietrich
Published: April 2024

Aim:
Natriuretic peptides provide valuble information about cardiac dysfunction. The clinical relevance of elevated circulating midregional pro-atrial natriuretic peptide (MR-proANP) 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 MR-proANP for recurrent cardiovascular disease (CVD) events in stable CHD patients, simultaneously controlling for a large number of potential confounders.

Methods:
Plasma concentrations of MR-proANP (BRAHMS) were measured at baseline in a cohort of 1,048 patients aged 30-70 years with CHD. The Cox proportional hazards model was used to determine the prognostic value of MR-proANP on a combined CVD endpoint after adjustment for covariates.

Results:
The median MR-proANP level was 135.2 pmol/L (interquartile range 95.2-185.8). Elevated MR-proANP levels were associated with higher age, obesity, history of hypertension, diabetes, and heart failure, higher number of affected vessels, initial management of CHD, and left-ventricular dysfunction in a statistically significant way. Furthermore, after adjustment for age and gender MR-proANP was correlated with CRP (correlation coefficient (R=0.21), NT-proBNP (R=0.72), creatinine clearance (R= -0.32), cystatin C (R=0.43), hsTnT (R= 0.51) respectively (all p-values <0.0001). During a median follow-up of 8.1 years, 150 patients (21.1%) experienced a fatal- or non-fatal secondary CVD event. In a multivariate model MR-proANP was associated with a hazard ratio (HR) of secondary CVD events of 3.00 (95% confidence interval (CI), 1.70-5.28) when extreme quartiles were compared. Further adjustment for NT-proBNP attenuated the association only slightly (HR 2.67; 95% CI, 1.48-4.79).

Conclusions:
Elevated MR-proANP levels in stable CHD patients are associated with several CVD disorders and predict long-term CVD events in these patients.
Abstract 16986: A New Cardiac Muscle Post-Translational Modification: Detection of Protein Arginine Deiminases and Protein Citrullination in Heart Tissue
Authors: Fert-Bober Justyna , Uhrigshardt Helge , Halushka Marc , Andrade Felipe , Giles Jon , Bathon Joan , Van Eyk Jennifer
Published: April 2024

Protein citrullination originates from enzymatic deimination of amino acid arginine in a protein and is involved in various biological processes during health and disease. However, it has not been investigated in heart. Therefore, our goal was to identify novel substrates for peptidylarginine deiminase (PAD), enzyme responsible for this modification and associate it with changes in protein citrullination during heart failure (HF).

METHODS:
Proteomics methods were used to identify citrullinated proteins and the site of modification in control mouse and control vs. HF human heart tissue (5 per group). The characterization of deiminated proteins was facilitated by modification of peptide-bound citrullineted Arg residues with antipyrine and butanedione, allowing for the unambiguous identification by mass spectrometry. Verification of citrullinated proteins was carried out by 2DE (modification causes pI shift) and western blot with anti-citrullinated antibody. PAD enzyme expression was determined using RT-PCR reaction and immunohistochemistry.

RESULTS:
We detected up to 20 proteins markedly modified by PAD in vitro and in vivo in mouse heart including myofilament and mitochondria proteins. Similar proteins were identified to be citrullinated in control human heart tissue including tropomyosin (R220), myosin heavy and light chain (R1176, 1434 and 1479) and myosin binding protein C (R696). Importantly, we showed a specific residues deimination associated with the HF, e.g. tropomyosin from HF samples has 3 different citrullinated sites (R 125, 133, 238) compared to control. The PAD enzyme is present in mouse isolated cardiomyocytes and cardiac fibroblast (predominantly PAD2 vs. PAD2/PAD4, respectively). Immunohistochemistry of control human hearts had positive PADs staining in cardiomyocytes.

CONCLUSIONS:
Our study demonstrates, for the first time that protein citrullination is a viable post-translational modification in heart tissue and corresponds to the cardiac expression of PAD. Furthermore we showed that citrullinatated residues are altered HF suggesting that this novel PTM could have a regulatory role.
Abstract 17002: Post-Arrest Arterial Hyper-Oxygenation and Cardiac Mitochondrial Function
Authors: Yeh Steven , Angelos Mark G
Published: April 2024

Introduction:
Post-ischemic re-oxygenation is necessary to minimize ischemic injury, but itself can induce further reperfusion injury through the induction of reactive oxygen species (ROS). Utilization of oxygen within the cell primarily occurs in the mitochondria. The objective of this study was to determine heart mitochondrial function following 1 hour of controlled arterial oxygenation following cardiac arrest and ROSC. We hypothesized that arterial hyper-oxygenation following ROSC would result in greater impairment of heart mitochondrial function.

Methods:
Two experimental protocols were completed using a rat KCl arrest model. In experiment 1, animals underwent a 6 min cardiac arrest and were resuscitated with standard thumper CPR, ventilation and epinephrine and then ventilated with 100% O2 (hyperoxia group) or 40% O2 (normoxia group) for 60 min. In experiment 2, animals underwent a 25 min cardiac arrest and were resuscitated with cardiopulmonary bypass. Arterial PO2 was titrated to either hyperoxic or normoxic levels for 60 min post ROSC. In both experiments, at the end of 60 min, heart mitochondria were isolated and mitochondrial respiratory function was compared between groups.

Results:
In experiment 1, post-ROSC arterial PaO2 was 280 ± 40 mm Hg in the hyperoxic group and 105 ± 10 mm Hg in the normoxic group. Mitochondrial respiration, defined as respiration control ratio (state 3/4 respiration), was significantly higher in the normoxic group compared to the hyperoxic group (n=6/group, p <0.05). In experiment 2, during the 60 min post ROSC period, arterial PaO2 was 441 ± 10 mm Hg in the hyperoxic group and 107 ± 9 mm Hg in the normoxic group (n=6/group, p<0.001). Mitochondrial respiration, 60 min after ROSC, was significantly higher in the hyperoxic group compared with the normoxic group (n=6/group, p<0.05). Post-ROSC arterial hyperoxemia (compared with normoxemia) was associated with worse mitochondrial function after a short cardiac arrest but improved mitochondrial function after a prolonged cardiac arrest. We conclude that post-ischemic arterial hyperoxia is an important variable in mitochondrial functional recovery but the severity of the ischemia may attenuate this effect by limiting reperfusion oxygen delivery to the mitochondria.
Abstract 17055: A New Cohort Confirms the High Prevalence and Severity of Endothelial and Microvascular Dysfunction Among Women with Symptoms of Ischemia and No Obstructive Coronary Artery Disease: the NHLBI-sponsored Women's Ischemia Syndrome Evaluation (WISE)
Authors: Anderson R. David , Petersen John W , Mehta Puja K , Wei Janet , Johnson B. Delia , Handberg Eileen M , Kar Saibal , Samuels Bruce , Azarbal Babak , Kothawade Kamlesh , Kelsey Sheryl F , Sharaf Barry , Shaw Leslee J , Bairey-Merz C. Noel , Pepine Carl J
Published: April 2024

Background:
Previous evaluations in women studied in 1997-2001 with symptoms/signs of ischemia without obstructive coronary artery disease demonstrated a relatively high prevalence of both endothelial and microvascular dysfunction: these abnormalities were then shown to predict adverse events in follow-up. Coronary reactivity testing (CRT) with flow reserve (CFR <2.5), vasoconstriction to acetycholine (ACH), or <20% vasodilation to nitroglycerin (NTG) were taken as abnormal responses. To our knowledge, the prevalence of these disorders has not been reassessed in a more contemporary population of women.

Methods:
Accordingly, we studied a contemporary (2009-2011) WISE cohort with symptoms/signs of ischemia but without obstructive CAD undergoing CRT and compared their findings to those from the original WISE cohort. Following demonstration of no obstructive CAD, defined as <50% epicardial stenosis in any coronary artery, patients underwent CRT. Using a Doppler transducer-tipped guide wire (Volcano ®FloWire 300cm) in a left coronary artery, CFR was measured after intracoronary (IC) adenosine, followed by sequentially IC ACH and IC NTG with quantitative angiography and Doppler flow measurement evaluated by core labs.

Results:
Among the 94 women who underwent CRT, the mean age was 53 (23-73 years), 37% were non-Caucasian. Of these 33% had hypertension, 41% hyperlipidemia, 6% diabetes, 18% used hormone replacement, and 49% had a history of smoking. Coronary reactivity data for the two cohorts is shown in the Table.

Conclusion:
Compared with our prior WISE cohort of women with signs and symptoms of ischemia but without obstructive CAD, both endothelial and microvascular dysfunction remain highly prevalent and similar in degree in a contemporary cohort. Because these abnormalities have been linked to prediction of major adverse cardiac events, clinical trials targeting these pathways appear to be indicated.