bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 15657: Regulation of Cardiac Regeneration by Hippo Pathway and Dystrophin Glycoprotein Complex
Authors: Morikawa Yuka , Martin James F
Published: July 2021

Regeneration of the mammalian heart is limited in adults. In rodents, endogenous regenerative capacity exists during development and in neonate but is rapidly repressed after birth. We are elucidating the mechanisms responsible for regenerative repression and applying this knowledge to reactivate cardiac regeneration in adult hearts. We have previously shown that the Hippo pathway is responsive for regenerative repression, however, the molecular and cellular mechanism responsible remain unclear.

The Hippo pathway controls heart size by repressing myocardial cell proliferation during development. By deleting Salv, a modulator of Hippo pathway, we found myocardial damage in the postnatal and adult heart was repaired anatomically and functionally. This heart repair occurred primarily through proliferation of preexisting cardiomyocyte. We observed that cardiomyocytes in border the zone protrude and fill the damage area during Hippo-mediated cardiac regeneration and thus preventing formation of fibrotic scars. The molecular analysis identified components of dystrophin glycoprotein complex (DGC) as downstream targets of Hippo pathway. The DGC anchors the cytoskeleton and extracellular matrix and is involved in cell migration. The studies using the muscular dystrophy mouse model, mdx, reveals that DGC is required for endogenous cardiac regeneration and cardiomyocyte protrusion. Taken together, we show that cardiomyocyte protrusion is an essential process for cardiac regeneration and the Hippo pathway regulates it through regulating DGC. Our studies provide insights into the mechanisms leading to repair of damaged hearts from endogenous cardiomyocytes and novel information into DGC function.
Abstract 15677: Statin Prescription and Dose Intensity Among Elderly Medicare Beneficiaries, by CV Disease Diagnosis and Prescriber Specialty
Authors: Yusuf Akeem , Wiggenhorn Christopher , Hardin Jill , Kilpatrick Ryan D , Herzog Charles A
Published: July 2021

Introduction:
Statin use is known to benefit elderly patients with cardiovascular (CV) disease. However, little is known about the rate and dose of statin prescriptions or prescriber specialty among elderly Medicare beneficiaries with a history of various CV diseases.

Method:
In this retrospective analysis of 2007-2010 Medicare claims data, we identified enrollees with history of prevalent CV disease or diabetes (DM) (N=613,674, 68% women, 7.5% black, mean [±SD] age 76.7 [±8] years). We used a disease hierarchy approach and included 9 subgroups: patients with a history of myocardial infarction (MI), unstable angina, ischemic stroke, stable angina, transient ischemic attack (TIA), carotid stenosis, coronary revascularization (PCI/CAB), peripheral arterial disease (PAD), or DM. We identified statin users at diagnosis or within 12 months post-diagnosis; categorized statin therapy as high-, moderate-, and low-intensity; and examined the clinical specialty of statin prescribers.

Results:
Overall, 41% of patients had at least one cardiologist visit in 2010. Statin use was highest among PCI/CAB patients (81.5%) and lowest among PAD patients (45.5%) (Table 1). Similar proportions of patients with MI (72.8%) and unstable angina (71.4%) were prescribed statins. High-intensity and low-intensity statins were most commonly prescribed to MI patients (22%) and TIA patients (13.7%), respectively. Overall, family/internal medicine was the most common specialty of statin prescribers across all CV disease groups (Table 2). PCI/CAB patients were most likely to receive prescriptions from cardiologists (23.8%). Endocrinologists prescribed 2.3% of statins for DM patients. Most PAD patients (62.9%) were prescribed statins by family/internal medicine clinicians.

Conclusions:
Statin use is lower among elderly PAD and TIA patients. More comprehensive assessment of statin use is needed, and of its determinants and associated outcomes in elderly CV patients.
Abstract 15702: Reperfusion Therapy With Rapamycin in Diabetic Heart: Essential Role of STAT3 Signaling
Authors: Das Anindita , Salloum Fadi N , Durrant David , Kukreja Rakesh C
Published: July 2021

Background:
Diabetic patients suffer augmented severity of myocardial infarction. Excessive activation of the mammalian target of rapamycin (mTOR) is implicated in diabetic complications and plays a critical role in myocardial reperfusion injury following ischemia. mTOR inhibition with rapamycin improves cardiac function in type 2 diabetic (T2D) heart. Since activated STAT3 is decreased in T2D heart, we hypothesized that reperfusion therapy with rapamycin would reduce myocardial infarct size in these hearts through STAT3 signaling.

Methods and Results:
Hearts from adult male db/db or wild type (WT) C57 mice were isolated and subjected to 30 min of ischemia and 60 min of reperfusion in Langendorff mode. Rapamycin (100 nM) was infused at the onset of reperfusion. Myocardial infarct size (IS) was significantly reduced in rapamycin-treated mice (13.3±2.4%) compared to DMSO control (36.2±1.3%) or WT mice (27.7±1.1%) (Fig. A). Rapamycin treatment restored phosphorylation of STAT3 and enhanced AKT phosphorylation (target of mTORC2), but significantly reduced ribosomal protein S6 phosphorylation (target of mTORC1) in heart (Fig. B). We further investigated the effect of rapamycin in high fat diet (HFD) fed inducible cardiac-specific STAT3-deficient (MCM TG:STAT3flox/flox) and WT mice (MCM TG:STAT3flox/flox). Rapamycin treatment during reperfusion significantly reduced IS in WT mice following I/R but not in STAT3-deficient mice (Fig. C). Rapamycin treatment during reoxygenation following 40 min of simulated ischemia also demonstrated resistance against necrosis (trypan blue staining) and apoptosis (TUNEL assay) in primary cardiomyocytes isolated from HFD-fed WT mice but not in cardiomyocytes from HFD-fed STAT3-deficient mice (Fig. D).

Conclusion:
STAT3 signaling plays a critical role in reducing myocardial infarct size and attenuating cardiomyocyte death following reperfusion therapy with rapamycin in T2D.
Abstract 15747: Over-Expression of Insulin-Like Growth Factor-1 by Human Cardiac Stem Cells Enhances Long-Term Retention of Transplanted Cells While Promoting Salvage of Injured Myocardium
Authors: Jackson Robyn , Tilokee Everad L , Latham Nicholas , Ye Bin , Boodhwani Munir , Chan Vincent , Ruel Marc , Suuronen Erik J , Stewart Duncan J , Davis Darryl R
Published: July 2021

Background:
Insulin-like growth factor (IGF-1) is a potent pro-survival cytokine that is not robustly expressed by human cardiac stem cells (CSCs). Previously, we have shown that paracrine engineering of CSCs with IGF-1 improves cell-mediated cardiac repair. Here, we explore the mechanisms underlying IGF-1 enhanced cardiac repair by CSCs.

Methods/Results:
Sub-culture of isolated c-Kit+, CD90+ and lineage negative cells (c-Kit-/CD90-) demonstrated that the natural low level production of IGF-1 by CSCs (149±16 pg/ml*mg) is secreted by all 3 sub-populations. After culture in hypoxic reduced serum media, lentiviral mediated over-expression of IGF-1 enhanced proliferation (population doubling time: 1.4±1.7 vs.-0.9±1.2 and -1.9±2.4 days, respectively; p≤0.01), expression of pro-survival transcripts (AKT, ERK and MAPK pathways) and pro-survival proteins (Bcl-2, Bcl-x, HIF-1a; p≤0.01) while decreasing expression of apoptotic markers (3.5±0.9 and 3.7±0.9 fold less annexin V; p≤0.01) as compared to GFP- and non-transduced CSCs. The high expression of the IGF-1 (79±3%) or the insulin receptor (61±5%) on CSCs suggests that autocrine pro-survival pre-conditioning underlies these effects. Direct and indirect co-culture of CSCs with neonatal rat ventricular cardiomyocytes (NRVMs) within hypoxic conditions demonstrated that IGF-1 promoted indirect myocardial repair by increasing NRVM viability and pro-survival signaling (Bcl2+; p≤0.01) while reducing apoptosis (annexin V+; p≤0.05) as compared GFP- or non-transduced CSCs. Transplant of CSCs genetically engineered to over-express IGF-1 into immunodeficient mice one week after infarction boosted IGF-1 content within infarcted tissue by 2.9±0.2 fold (p=0.004) and long-term engraftment (+4 weeks human alu content increased by 9.1±4 fold; p=0.05) while reducing myocardial apoptosis (3.4±0.3 and 2.5±0.5 fold reduction expression of Bax and p53, respectively; p<0.05) and long-term myocardial scarring (+ 4 weeks 2.2±0.4 fold less; p=0.01) as compared to GFP-transduced CSCs.

Conclusions:
Transplantation of IGF-1 enriched CSCs enhances cardiac repair by boosting transplant cell survival and reducing myocardial apoptosis to improve myocardial function and salvage of damaged myocardium.
Abstract 15754: Genetically Engineered Stem Cell-Derived Model for Therapeutic Discovery in Long QT Syndrome
Authors: Leyton-Mange Jordan S , Jang Min-Young , Lynch Stacey N , Mills Robert W , Ling Xaio , Ellinor Patrick T , Milan David J
Published: July 2021

Introduction:
Long QT syndrome (LQTS) is caused by delayed ventricular repolarization and is a cause of sudden death. In a recent chemical screen with an in vivo zebrafish model of LQTS-type 2, we identified 2-methoxy-N-[4-methylphenyl] benzamide (2MMB), which shortens the ventricular action potential (Figure A).

Methods:
We initially used a zebrafish LQT2 model to perform a structure-activity relationship (SAR) study with 50 substituted benzanilide derivatives. We generated a human LQT-type 1 embryonic stem cell (hESC) model with a bi-allelic disruption of KCNQ1 in the hESC H7 line using CRISPR. KCNQ1-/- hESC-derived cardiomyocytes (hESC-CM) were electrophysiologically characterized and used to perform secondary structure activity studies for a subset of benzanilide derivatives (Figure A).

Results:
We observed a range of biological activities among the 50 analogs tested in the zebrafish assay, including several compounds with no activity and several that were more potent than 2MMB. Genetically engineered LQT1 hESC-CMs had diminished IKs current (Figure B) and prolonged action potentials that significantly shortened upon 2MMB treatment (Figure C). SAR studies in the LQT1 hESC-CMs confirmed improved potency for two of the compounds and lack of activity for one. A single discrepancy existed for a compound without activity in our zebrafish assay but significantly shortened action potentials in hESC-CMs.

Conclusions:
We report the use of a physiologically faithful genetically engineered LQT1 hESC line for therapeutic discovery in LQTS. Inclusion of hESC-CMs in future studies may complement animal testing by enabling direct screening on disease specific human tissue.
Abstract 15766: Repolarization Parameters are Significantly Prolonged in Many Patients With Left Bundle Branch Block and Acute Myocardial Infarction
Authors: Dodd Kenneth W , Elm Kendra D , Dodd Erin M , Smith Stephen W
Published: July 2021

Introduction:
In patients with normal conduction, prolongation of repolarization parameters such as the QTc interval, JTc interval, and T-wave peak to end (Tpe) interval are associated with cardiac ischemia, ventricular tachydysrhythmias, and sudden cardiac death. These intervals are often considered “prolonged” at QTc >450 ms, JTc > 360 ms, and Tpe > 120 ms. We are unable to find published manuscripts that report these parameters in LBBB. Furthermore, it has been proposed that the Bazett correction formula for QTc and JTc overestimates repolarization duration in patients with conduction disturbances.

Aim:
To report the QTc, JTc, and Tpe intervals in ED patients with LBBB with and without MI and to compare common correction formulas.

Methods:
Retrospectively, we identified ED patients with LBBB and ischemic symptoms: with no MI, with NSTEMI, and with angiographically-proven acute coronary occlusion (STEMI). The QT, JT, and Tpe intervals were measured manually in leads II, V3, and V5; the longest of each was used. QTc and JTc intervals were calculated by Bazett’s, Hodges’ and Framingham formulas. Statistics were by two-tailed Student’s t-test and Mann-Whitney U test.

Results:
The no-MI, NSTEMI, and STEMI groups consisted of 105, 24 and 33 patients. In the STEMI group, 24.3% of patients had Tpe >= 120 ms compared to 4.8% of no-MI patients (p < 0.001). By Hodges’ formula, 53.1% of patients with LBBB had QTc >= 450 ms and 12.3% had JTc >= 360 ms.

Conclusion:
Repolarizaton parameters are prolonged in many patients with LBBB. The Tpe interval, which has been proposed as a marker of transmural repolarization heterogeneity due to ischemia, is significantly prolonged in patients with STEMI and LBBB when compared to LBBB patients without MI. Between the STEMI, NSTEMI, and no-MI groups there was no significant difference in QTc or JTc by any formula (see Table 1). However, the overall mean QTc by Bazett’s was significantly longer than Hodge’s or Framingham (see Table 2).
Abstract 15805: PCSK9 R46L, Lower LDL and Cardiovascular Disease Risk in Familial Hypercholesterolemia
Authors: Baass Alexis
Published: July 2021

Introduction:
Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a down-regulator of the low density lipoprotein receptor (LDLR). Familial hypercholesterolemia (FH) is a autosomal monogenic disease associated with high LDL-C concentration and cardiovascular risk.

Hypothesis:
This study aimed to examine whether the PCSK9 R46L loss of function mutation found in a cohort of FH patients will be associated with lower LDL-C and cardiovascular risk.

Methods:
We studied FH patients attending the IRCM Lipid Clinic and whose DNA genotyping was positive for LDLR mutations. The presence of the PCSK9 loss of function R46L missense mutation was determined among a cohort of 582 FH patients by sequencing.

Results:
Frequency of the R46L variant was 3%. Comparison of their lipid profile showed that carriers had significantly reduced LDL-C (11%, p<0.001), TC (9%, p<0.01), ApoB (10%, p<0.01) and non-HDL (12%, p<0.001) concentrations compared to non-carriers. The analysis of physical xanthomata among both groups, showed a decreased average number of xanthoma per individual in R46L carriers (0.33 and 0.76 respectively, p<0.001). Importantly, the R46L mutation was associated with a significant 66% (p=0.05) lower risk of cardiovascular events compared to non-carriers.

Conclusion:
Our study showed that the presence of the PCSK9 loss of function R46L mutation in the genotype of FH patients is beneficial for the lipid homeostasis and down-regulate the effect of the LDLR mutation in terms of accumulation of LDL-C, ApoB , total cholesterol, non-HDL and thereby, lowers the coronary heart disease risk of PCSK9 LOF mutation carriers. It is therefore very likely that anti-PCSK9 therapy will be useful in reducing cardiovascular risk in FH patients.
Abstract 15830: Elevated Resting Heart Rate is Associated With Impaired Quality of Life and Worse NYHA Functional Capacity in Patients With Chronic Heart Failure: Results From REALITY HF Study
Authors: Cavusoglu Yuksel , Kozan Omer , Temizhan Ahmet , Kucukoglu Serdar
Published: July 2021

Purpose:
Resting heart rate (HR), health related quality of life (HQoL) and NYHA functional capacity are referred as important determinants of prognosis and targets of therapy in heart failure (HF). REALITY HF (Resting Heart Rate and Real Life Treatment Modality in Outpatients with Left Ventricular Systolic Dysfunction) study data were analyzed for the evaluation of any relationship of resting HR with HQoL assessed by Kansas City Cardiomyopathy Questionnaire (KCCQ) and NYHA functional class.

Methods:
REALITY HF was a multicenter, prospective registry designed to evaluate HF patients’ characteristics and effects of treatment modalities on resting HR and enrolled 1057 patients (age 61±12 years) with LVEF <40%. 781 (74%) patients in sinus rhythm were included in this analysis. Patients were classified into 4 groups according to the quartiles of HR: Q1:<68 bpm (n=234), Q2:69-75 bpm (n=189), Q3:76-87 bpm (n=194) and Q4:>87 bpm (n=164). KCCQ was completed in a random sample of 320 (Q1:n=27, Q2:n=99, Q3:n=125, Q4:n=69) patients, in which higher scores show better patient’s health status.

Results:
During enrollment, 82% of patients were receiving ≥2 drugs including ACE[[Unable to Display Character: İ]]/ARB, beta blocker, aldosterone blocker, diuretic or digoxin. Resting HR was 76±14 bpm and 68% of patients had a resting HR ≥70 bpm. KCCQ overall summary score (OSC) was found to be 75.7±13.2 in those in Q1, 65.5±20.8 in Q2, 64.4±20.6 in Q3 and 58.3±21.2 in Q4 (p=0.004) and KCCQ clinical summary score (CSS) was 80.4±15.7 in those in Q1, 70.0±22.4 in Q2, 69.9±21.9 in Q3 and 63.8±23.3 in Q4 (p=0.016). Also, there was a significant negative correlation between resting HR and OSC (p=0.008) or CSS (p=0.031). The distribution of NYHA-I patients for Q1, Q2, Q3 and Q4 were 40.7%, 22.8%, 23.8% and 12.7%, NYHA-II patients-30.8%, 23.1%, 27.2% and 18.9%, NYHA-III patients-21.2%, 23.9%, 24.3% and 30.6% and NYHA-IV patients-22.7%, 34.1%, 22.7% and 20.5%, respectively (p<0.001). Also, resting HR were found to gradually and significantly increase across NYHA categories (72.8±12 bpm in NYHA-I, 76.1±13 bpm in NYHA-II, 80.2±15 bpm in NYHA-III and 78.9±16 bpm in NYHA-IV, p<0.001).

Conclusions:
These results suggest that elevated resting HR in HF patients is associated with impaired HQoL and worse NYHA functional capacity.
Abstract 15844: Plasma Parathyroid Hormone is Independently Related to 24-Hour Pulse Wave Velocity in Patients With Primary Hyperparathyroidism - Insights fFom The EPATH Study
Authors: Wetzel Julia , Verheyen Nicolas , Belyavskiy Evgeny , Schmidt Albrecht , Colantonio Caterina , Kraigher-Krainer Elisabeth , Gaksch Martin , Grübler Martin , Schmid Johannes , Fahrleitner-Pammer Astrid , Pieske Burkhard , Pilz Stefan , Tomaschitz Andreas
Published: July 2021

Introduction:
Accumulating evidence indicated that high parathyroid hormone (PTH) is associated with increased cardiovascular risk. The impact of PTH on vascular structure and function is, however, still unclear. We evaluated the relationship between pulse wave velocity (PWV) as a novel index of arterial stiffness and circulating levels of PTH in patients with PTH-excess (primary hyperparathyroidism (pHPT)).

Methods and Results:
We analyzed baseline data of the ongoing randomized, double-blind, placebo-controlled “Effect of Eplerenone on Parathyroid Hormone Levels in Patients with Primary Hyperparathyroidism” (EPATH) study. Inclusion criteria were age of at least 18 years and a diagnosis of pHPT according to international guidelines. Standardized blood sampling was performed after an overnight fast and 24h PWV was measured by a validated non-invasive device for ambulatory hemodynamic monitoring (Mobil O Graph, I.E.M., Stolberg, Germany). Our analysis comprised 92 pHPT patients with a mean age of 68.5 +/- 9.7 years (71 % females) and a median PTH of 102 (IQR 81 - 132) pg/ml. Mean 24h PWV was 9.8 +/- 1.8 m/s, mean daytime and mean nighttime PWV were 10.0 +/- 1.7 m/s and 9.6 +/- 1.8 m/s, respectively. In multivariate linear regression analyses adjusted for age, sex, body mass index, smoking status, mean systolic and mean diastolic 24h blood pressure, antihypertensive medication, type 2 diabetes, 25-hydroxyvitamin D, serum calcium, intake of cinacalcet and fasting serum cholesterol PTH emerged as a strong predictor of mean 24h PWV (ß=0.30, p=0.012), daytime PWV and nighttime PWV (ß=0.30, p=0.011 and ß=0.30, p=0.019, respectively).

Conclusion:
In a selective cohort of patients with pHPT plasma PTH was strongly related to 24h PWV. These data strengthen the notion that PTH may impact on vascular function. Interventional and mechanistic trials are needed to evaluate modulatory effects on vasculature in patients with high PTH.
Abstract 15882: Gene-Panel Based Next Generation Sequencing (NGS) Greatly Improves Clinical Genetic Diagnostics in Inherited Cardiomyopathies
Authors: Jongbloed Jan D , Pósafalvi Anna , Niessen Renée C , Hoedemaekers Yvonne M , van der Zwaag Paul A , Barge-Schaapveld Daniela Q , Piers Sebastiaan R , van der Smagt Jasper J , Asselbergs Folkert W , de Boer Rudolf A , van den Berg Maarten P , Almomani Rowida , Sinke Richard J , van Tintelen J. P
Published: July 2021

INTRODUCTION:
NGS techniques can be successfully applied to find mutations underlying genetic cardiomyopathies. However, Exome Sequencing (ES) shows incomplete representation and coverage of exons, leading to clinically relevant mutations being missed. Thus, ES will, at least for now, coexist in clinical genetic diagnostics with other NGS-based strategies, such as gene-panel based resequencing. Therefore, we aimed at evaluating the yield of gene-panel based resequencing of 55 genes in cardiomyopathy patients referred to our department.

METHODS:
We constructed an enrichment kit targeting 55 cardiomyopathy genes and implemented this into routine diagnostics. We evaluated our first 162 patients: 47 fulfilled generally accepted clinical criteria for hypertrophic cardiomyopathy (HCM), 72 fulfilled the Mestroni criteria for dilated cardiomyopathy (DCM) and 3 were diagnosed with arrhythmogenic cardiomyopathy (ACM). In addition, 23, 11 and 6 cases showed signs of DCM, HCM and ACM, yet did not fulfill the formal criteria. Additional cosegregation analyses were performed to further support pathogenicity of potentially causal mutations.

RESULTS:
In the DCM cohort 40 pathogenic or likely pathogenic mutations were identified (55%; 40/72). Mutations in
TTN
were found in 14% of DCM patients (10/72). The yield in criteria positive HCM and ACM patients was 40% (17/43) and 33% (1/3). In patients not fully fulfilling criteria for DCM, HCM and ACM the yield was 52% (12/23), 36% (4/11) and 83% (5/6). In 13 % (21/162) of cases two or more (potentially) pathogenic mutations were identified. Results of cosegregation analyses supported pathogenicity of potentially causal mutations in 42 families. In 6 results argued against pathogenicity.

CONCLUSIONS:
Gene-panel based NGS results in a substantial increase in diagnostic yield for DCM patients compared to previous results of Sanger sequencing most prevalent genes (55% vs 20-25%).
TTN
mutations are most prevalent in DCM patients (14%). Higher diagnostic yields are achieved for patients fulfilling DCM and HCM criteria. Cosegregation analyses further support pathogenicity of potentially causal mutations. Together, our gene-panel based approach greatly improved genetic diagnostics in cardiomyopathies.
Abstract 15898: Toll-Like Receptor 2 Methylation and Dietary Flavonoid Intake Modify the Association Between Fine Particle Exposure and Cardiac Autonomic Dysfunction: The Normative Aging Study
Authors: Zhong Jia , Colicino Elena , Lin Xinyi , Mehta Amar , Kloog Itai , Zanobetti Antonella , Byun Hyang-Min , Bind Marie-Abèle , Cantone Laura , Prada Diddier , Tarantini Letizia , Sparrow David , Vokonas Pantel , Schwartz Joel , Baccarelli Andrea
Published: July 2021

Introduction:
Short-term exposure to fine particles (PM
2.5
) is associated with reduced heart rate variability (HRV), a strong predictor of cardiac mortality among the elderly. Identifying modifiable factors that confer susceptibility is essential for personalized intervention. We evaluated whether
Toll-Like Receptor
2 (TLR2)
methylation [[Unable to Display Character: –]] a reversible epigenetic process affecting immunoregulation [[Unable to Display Character: –]] modified the effect of PM
2.5
on HRV, and investigated the impact of flavonoid and folic acid intake on
TLR2
methylation.

Methods:
We collected longitudinal measures of HRV and PM
2.5
over 11 years among 573 elderly men from the Normative Aging Study.
TLR2
methylation was analyzed using bisulfite-treated Pyrosequencing from 500 participants. Harvard Food Frequency Questionnaire was administrated to assess average daily flavonoid and folic acid intake in the past year.

Results:
Every 10 μg/m
3
increase in 48 hours PM
2.5
moving average was associated with 7.23% (95% CI, 2.95%, 11.33%;
P
= 0.03) and 13.88% (95% CI, 1.39%, 24.79%;
P
= 0.04) reduction in the standard deviation of normal-to-normal intervals (SDNN) and low frequency (LF), respectively.
TLR2
hypermethylation exacerbated the post-exposure SDNN, LF, and high frequency (HF) reduction (
P
global
= 0.03, 0.05, 0.04, respectively). Every 10-fold increase in flavonoid intake was associated with 0.41 %5mC lower in
TLR2
methylation (95% CI, 0.04, 0.78;
P
= 0.03). High flavonoid intake weakened the association between PM
2.5
and LF by lessening 33.01% (95% CI, 1.56, 74.22;
P
= 0.04) LF reduction per 10 μg/m
3
increase in PM
2.5
, compared to the low intake group. Folic acid intake was not associated with
TLR2
methylation.

Conclusion:
TLR2
hypermethylation confers the vulnerability to post-exposure HRV decline of the elderly when confronted with air pollution peaks, while high flavonoid intake emolliates the hazardous effect of pollution, likely through regulating
TLR2
methylation.
Abstract 15923: CaMKII Links ER Stress Signaling in Pressure Overload-Induced Left Ventricular Hypertrophy and Failure
Authors: Cheng Guangming , Zhao Lin , Chen Lei , Chen Xing , Davani Arash , Samanta Anweshan , Girgis Magdy , Elias Harold , Yang Yanjuan , Vincent Robert J , Hauptman Jeryl , Dawn Buddhadeb
Published: July 2021

Introduction:
Recent evidence indicates that the multifunctional Ca2+/calmodulin-dependent protein kinase II (CaMKII) plays a key role in pathogenesis of cardiac hypertrophy and failure. The cytosolic calcium resulting from endoplasmic reticulum (ER) also involves CaMKII. However, the molecular connection between ER stress and LV hypertrophy remains unclear.

Hypothesis:
We hypothesized that CaMKII serves as the molecular link between ER stress and LV hypertrophy.

Methods:
We used mice with genetic deletion of C/EBP Homologous Protein (CHOP), a mediator of ER stress. Transverse aortic constriction (TAC) or sham surgeries were performed in age-matched male CHOP knockout (KO) mice and controls to induce pressure overload. Serial echocardiography was performed prior to (baseline, BSL) and weekly after TAC. Mice were sacrificed after 6 weeks for measurement of heart weight, morphometry, histology, and protein assays. Separate groups of CHOP KO and control mice were sacrificed at 2 weeks after TAC for protein assays.

Results:
Pressure overload resulted in progressive LV dysfunction (Figure) and hypertrophy in control mice compared with baseline. At 6 wks after TAC these adverse effects of pressure overload were significantly attenuated in CHOP KO mice as evidenced by greater LV EF (Figure) and smaller LV mass compared with controls. Compared with control hearts, phosphorylation of CaMKII was significantly reduced in CHOP KO hearts at 2 and 6 weeks after TAC (Figure). The phosphorylation of eIF2α, a signaling molecule upstream of CHOP in the ER stress pathway was significantly increased in CHOP KO hearts after TAC compared with control mice (Figure).

Conclusion:
Genetic deletion of CHOP attenuates LV hypertrophy and dysfunction induced by pressure overload; and CaMKII serves as a link between ER stress and hypertrophic signaling. Potential modulation of CaMKII and CHOP signaling may be used to ameliorate LV hypertrophy in patients with cardiovascular diseases.
Abstract 15940: Calcium and Insulin Regulate the Novel Glucose Transporter 8 (GLUT8) in the Healthy and Diabetic Myocardium
Authors: Martinez Emilie , Maria Zahra , Periasamy Muthu , Lacombe Veronique
Published: July 2021

Diabetes, an epidemic disease, is associated with the development of diabetic cardiomyopathy. Glucose uptake from the bloodstream into the cell is the rate-limiting step in whole body glucose utilization and is regulated by a family of membrane proteins called the glucose transporters (GLUT). The translocation of GLUT4, the main isoform, to the cell surface is insulin and contraction/calcium dependent in striated muscle. Contraction is regulated by the sarcoplasmic reticulum calcium ATPase (SERCA) pump. We recently demonstrated that diabetes impairs cardiac GLUT4 trafficking due to alterations of insulin signaling pathway and SERCA pump activity. However, the role of other GLUTs in the heart is still not elucidated. Although GLUT8 is highly expressed in the heart and could play a key role in cardiac glucose transport, its function and regulation are unknown. We hypothesized that, as for GLUT4, insulin and calcium will regulate GLUT8 translocation to the myocardial cell surface, which will be impaired during diabetes. Active cell surface GLUT (4 & 8) content was quantified by a biotinylated photolabeled assay in both intact perfused myocardium and isolated ventricular myocytes. To our knowledge, we are the first to apply this technique to GLUT8. Total GLUT (4 & 8) protein expression was measured by Western blot. Diabetes was induced by streptozotocin injection in wild type (WT) and transgenic (TG) mice overexpressing the SERCA pump in the heart and compared to their respective healthy littermates (n=16/group). In healthy myocytes, GLUT8 was primarily located intracellularly under basal condition, as for GLUT4. Insulin, calcium and isoproterenol stimulation (a beta-adrenergic agonist) significantly increased the translocation of both GLUT-4 and -8 to the cell surface. In addition, total GLUT-4 and -8 protein content was increased by 30 and 40% (P<0.05), respectively, in TG healthy mice overexpressing the SERCA pump compared to WT mice. As for GLUT4, active cell surface GLUT8 was decreased by 80% (P<0.05) in the diabetic ventricle but was restored by SERCA overexpression. Overall, our data suggest that, as for GLUT4, GLUT8 is a novel insulin-sensitive GLUT isoform in the heart, and its translocation is regulated by both insulin and calcium dependent pathways.
Abstract 15962: VO2 Kinetics are Impaired in Patients With Heart Failure With Preserved Ejection Fraction (HFpEF)
Authors: Sarma Satyam , Bhella Paul S , Hastings Jeffrey L , Palmer Dean , Levine Benjamin D
Published: July 2021

Background:
VO2 kinetics, or mean response time (MRT), quantifies oxygen uptake at the onset of exercise reflecting the rapidity with which the cardiovascular system can match the metabolic demands of skeletal muscle. Slowed kinetics leads to myofibril oxygen deficit which must be buffered by increased glycolysis and depletion of high energy phosphate stores. To date no studies have assessed changes in VO2 kinetics in HFpEF but growing evidence suggests peripheral abnormalities in oxygen utilization play an important role in exertional intolerance. We hypothesized HFpEF patients would have prolonged MRT during exercise compared to healthy senior controls reflecting abnormalities in skeletal muscle oxygen utilization.

Methods:
Eight senior control and 13 carefully screened HFpEF subjects underwent cardiopulmonary exercise testing. AV nodal blocking agents were held 5 half-lives and subjects performed submaximal exercise at 30% of VO2max for 5 minutes. VO2 and cardiac output (Qc; acetylene rebreathe) were collected at rest and during exercise. MRT and O2 deficit were calculated from VO2 response curves plotted on a breath by breath basis.

Results:
HFpEF patients had lower peak VO2 compared to seniors (13.2 ± 3.1 vs 20.3 ± 3.5 ml/min/kg; p<0.001). During fixed submaximal exercise, Qc, HR and VO2 were similar between groups. (Table) HFpEF patients had significantly prolonged MRT (69 v. 49s) compared to controls despite similar aerobic power and central cardiovascular and hemodynamic response. HFpEF patients also had a trend towards larger oxygen deficit (p=0.16) suggesting increased reliance on glycolytic metabolism during early exercise.

Conclusions:
HFpEF patients have slowed VO2 kinetics and an exaggerated O2 deficit during submaximal exercise. These findings establish abnormalities in muscle tissue oxygen utilization in HFpEF patients and suggest defects in oxygen metabolism are important contributors to exercise intolerance.
Abstract 15969: Epicardial Fat Thickness is an Overlooked Predictor of Cachexia in Heart Failure
Authors: Ozcan Cetin Elif H , Cetin Mehmet S , Canpolat Ugur , Aydin Selahattin , Akin Guray Yesim , Aras Dursun , Temizhan Ahmet , Aydogdu Sinan
Published: July 2021

Introduction:
Cachexia, as a miscellaneous phenomenon in heart failure (HF) with a prevalence of 10-15%, is associated with morbidity and mortality. Inflammation has been postulated as the hallmark factor in cachexia pathogenesis. Epicardial Fat Thickness (EFT) is the source of inflammatory mediators and has a close relationship with various cardiac diseases. Beyond other imaging modalities, echocardiography can be a simple and useful method in the evaluation of this tissue. In this study we objected to determine the relation of EFT and cardiac cachexia in heart failure

MATERIALS AND METHODS:
Our study consisted of totally 100 patients with heart failure with low ejection fraction (EF <30%) with BMI <25 kg/m2; 50 patients with cachectic HF and 50 patients with non-cachectic HF as the control group. The diagnosis of cachexia was based on the criteria as defined by Ewans WJ et al. (2008). EFT was measured with transthoracic echocardiography at systole in parasternal long axis view.

RESULTS:
In patients with cachectic HF (mean age 56.7±13.3, %44 male). EFT were higher than the control group (mean age 58.4±15.0, % 48 male).As a confounding factor; BMI was not different between groups (21.8±2.7 vs. 22.1±3.1, p=0.12).In correlation analysis of EFT with components of cachexia,EFT was significantly positively correlated with CRP (β=0.357 p<0.001) and negatively correlated with hand grip strength (β=-0.292, p=0.003), hemoglobin (β=-0,313 p=0.002) and albumin levels (β=-0.322 p=0.001). In multivariate analysis, EFT was an independent predictor of cardiac cachexia (OR:2.213, 95% CI:1.341-3.652, P=0.002).

DISCUSSION:
EFT, as an indicator of cardiac inflammatory status, seems to be an important predictor of cardiac cachexia. This noninvasive, simple measurement may guide us at risk stratification of patients with heart failure.
Abstract 15980: Regional Coronary Endothelial Function is Related to Coronary Wall Eccentricity on MRI
Authors: Hays Allison , Soleimanifard Sahar , Schär Michael , Steinberg Angela , Iantorno Micaela , Gerstenblith Gary , Stuber Matthias , Weiss Robert G
Published: July 2021

Introduction:
Coronary endothelial function (CEF) in patients with coronary artery disease (CAD) varies among coronary segments in a given patient for reasons that are incompletely understood.

Hypothesis:
Because both plaque eccentricity and coronary endothelial dysfunction are associated with adverse outcomes, we used noninvasive MRI to test the hypothesis that local coronary endothelial dysfunction is associated with local plaque eccentricity.

Methods:
We studied 13 healthy subjects (mean age±SEM: 55±7 years) and 21 patients with known CAD or CAD risk factors (61±4 years). To measure CEF, 3T coronary MRI was performed before and during isometric hand-grip exercise (IHE), a known endothelial-dependent stressor and % coronary cross-sectional area (CSA) and % coronary flow velocity (CFV) changes were measured. Black blood imaging of the coronaries was performed at the same cross sectional plane to quantify mean coronary wall thickness (CWT) and coronary eccentricity index (EI=max wall thickness (WT)-min WT)/max WT).

Results:
The changes in stress-induced CSA and CFV were significantly higher in healthy subjects (11.0±4.9% and 32.2±10.6% respectively) than in patients (2.2±1.5%, 12.8±4.9%, p<0.01 vs. healthy for both measures). Both mean CWT (1.11±0.06mm) and EI (0.47±0.2) were significantly lower in the healthy group than in the patients (CWT=1.59±0.07mm,p<0.001; EI= 0.57±0.02,p=0.006 vs. healthy). In the patient group, we observed a strong inverse relationship between stress-induced %CSA change and EI (r
2
=0.65, p<0.0001), but no significant relationship between %CFV change with stress and EI (r
2
=0.007,p=0.7). CWT was also significantly related to %CSA change (r
2
=0.47,p=0.002).

Conclusion:
We observed a strong inverse relationship between coronary endothelial macrovascular reactivity as measured by stress-induced %CSA change and the degree of coronary wall eccentricity in CAD patients. These findings indicate that an eccentric pattern of coronary wall remodeling is associated with abnormal local CEF, and therefore that anatomic and physiologic early indicators of coronary vascular pathology are closely related in atherosclerosis.
Abstract 15989: Intracoronary Infusion of Multicellular Cardiospheres Can Be Safely Used to Prevent Adverse Remodeling in a Pig Model of Myocardial Infarction
Authors: Gallet Romain , Tseliou Eleni , Dawkins James , Middleton Ryan , Valle Jackelyn , Kreke Michelle , Smith Rachel , Marbán Linda , Marbán Eduardo
Published: July 2021

Background:
Pre-clinical studies in rodents and pigs indicate that the self-assembling microtissues known as cardiospheres (CSp), when administered intramyocardially, may be more effective than dispersed CSp-derived cells (CDCs). However, the more desirable intracoronary (IC) route has been assumed to be unsafe for CSp delivery: CSp are large (>35 μm), raising concerns about likely microembolization.

Objective:
We sought to evaluate the safety and efficacy of IC delivery of allogeneic CSp in a porcine model of convalescent MI.

Methods:
Dosage was optimized by infusing CSp (3.25x10
5
particles [n=2], 6.5 x10
5
[n=3] and 1.3x10
6
[n=2], size=44±23, 29%>50μm) in the LAD of naïve pigs, looking for acute adverse effects (troponin I [TnI] leak, low TIMI flow, stunning). We next tested the efficacy of IC allogeneic Csp (1.3x10
6
; n=7) or vehicle (n=8) in a minipig model of chronic MI. Animals underwent MRI before infusion and 1 month later. Left ventricular (LV) ejection fraction (EF), scar mass and viable mass were evaluated at both time points.

Results:
In the dosing study, we observed no impairment of TIMI flow or LVEF after CSp infusion. TnI at 24 hours was 0.7±0.5ng/mL and did not differ among groups (P=0.11). In the post-MI study, EF was identical in the two groups at baseline. One month post-infusion, LV function was preserved in the CSp group but not in controls (ΔEF=+0.5±1.6% vs. -4.5±1.8%, p<0.001). CSp reduced scar mass (P<0.001) and increased viable mass (+17±8% vs. +6±6% from baseline, P=0.04) compared to controls. IC CSp also decreased LV end diastolic pressure (-7±4mmHg vs. -1±4 mmHg in control, P<0.01)) and increased cardiac output (+0.5±0.4 mL/min vs. -0.1±0.3mL/min, P<0.01.

Conclusions:
IC delivery of allogeneic CSp is safe and preserves LV function after MI. In addition, global hemodynamic improvement is observed, which may have significant clinical implications. The decision to use CDCs or CSp is not forced, therefore, by an inability to infuse CSp safely via the IC route.
Abstract 15996: Left-Variant Form of Slow-Fast AVNRT Requiring Ablation Along the Mitral Annulus
Authors: Otomo Kiyoshi , Takizawa Kaname , Inoue Naoto , Meguro Taiichiro
Published: July 2021

Background:
The reentry circuit of the slow-fast AV nodal reentrant tachycardia (AVNRT) has not been precisely delineated. Although conventional right-sided slow pathway ablation at the inferoseptal to midseptal tricuspid annulus (TA) or inside the coronary sinus (CS) is effective in most slow-fast AVNRT cases, rare cases of the left-variant form resistant to the conventional right-sided slow pathway ablation and requiring the left-sided ablation along the mitral annulus (MA) have been reported.

Purpose:
To evaluate the effects of the left-sided ablation along the MA in patients with the slow-fast AVNRT resistant to the conventional right-sided slow pathway ablation.

Methods & Results:
In 5 out of 250 cases with the slow-fast AVNRT who underwent the slow pathway ablation, extensive right-sided slow pathway ablation at the mid to inferoseptal TA, CS ostium or inside the CS (>10 applications) failed to eliminate tachycardia inducibility. In those 5 cases, the left-sided ablation along the inferoseptal to inferolateral MA with transseptal approach was performed during the sinus rhythm. In 2 cases, accelerated junctional rhythm was induced during the ablation along the MA and tachycardias were rendered non-inducible (upto one AV nodal echo beat). In other 2 cases, accelerated junctional rhythm was not induced during the ablation along the MA, but tachycardia became non-sustained (2-5 AV nodal echo beats). In the remaining one case, tachycardia still remained inducible even after extensive left-sided ablations.

Conclusion:
The left-variant forms of the slow-fast AVNRT were observed in 1.6% of all slow-fast AVNRT cases and the slow pathway ablation along the inferoseptal to inferolateral MA was effective for eliminating the tachycardia inducibility. The left-sided deviation of the reentrant circuit might explain the resistance to the right-sided slow pathway ablation and efficacy of the left-sided ablation along the MA in those cases.
Abstract 15999: The Divergent Effects of Exercise Training After Myocardial Infarction or Pressure Overload Depend Critically on Endothelial Nitric Oxide Synthase
Authors: Octavia Yanti , Deel Elza v , Waard Monique d , Boer Martine d , Moens An , Duncker Dirk J
Published: July 2021

AIMS:
Beneficial effects of aerobic exercise training are widely recognized. However, previously we discovered that the positive effects of exercise depend on the underlying cause of cardiac failure. Here we tested the hypothesis that endothelial nitric oxide synthase (eNOS) dependent regulation of the balance between nitric oxide and superoxide (O2•-) is critically involved in determining the effects of exercise.

METHODS:
Mice were exposed to 8 weeks of voluntary wheel running exercise training (EX) or sedentary housing (SED) immediately following myocardial infarction (MI), pressure overload from a transverse aortic constriction (TAC), or sham (SH) surgery. Subsequently, left ventricular (LV) ejection fraction (EF) was measured by echocardiography and Picrosirius Red staining was performed to measure collagen content. Additionally, total and NOS-dependent LV O2•- were measured using lucigenin-enhanced chemiluminescence without or with NOS inhibitor, L-NAME. eNOS uncoupling was evaluated by determining eNOS monomer dimer protein ratio and peroxynitrite (ONOO-) levels were measured through luminol-enhanced chemiluminescence.

RESULTS:
Cardiac dysfunction and fibrosis were ameliorated by exercise in MI but not in TAC mice (Table 1). MI and TAC both increased LV O2•- levels. Strikingly, EX diminished O2•- generation in MI, but exacerbated O2•- generation in TAC (Table 1). Furthermore, the EX-induced increase in O2•- levels in TAC were largely NOS-dependent. Accordingly, MI and TAC-induced eNOS uncoupling was normalized by EX in MI but aggravated in TAC mice (Table 1). Similarly, increased ONOO- levels following MI and TAC were diminished by EX in MI, but exacerbated by EX in TAC (Table 1).

CONCLUSIONS:
EX reduces eNOS-mediated cardiac oxidative stress in MI. In contrast, beneficial effects of EX are lacking in cardiac pressure-overload following TAC, due to EX-induced aggravation of ONOO- formation, eNOS uncoupling and concomitant oxidative stress.
Abstract 16004: The Prognostic Value of Automatically Detected Early Repolarization - A Focus on Hispanics
Authors: Aagaard Philip
Published: July 2021

Introduction:
Early repolarization (ER) associated with sudden cardiac death is based on the presence of >1mm J-point elevations in inferior and/or lateral leads with horizontal/downsloping ST-segments. Automated ECG readings of early repolarization (AER) obtained in clinical practice, on the other hand, are defined by ST segment elevation (ascending/upsloping ST-segments) in addition to J-point elevation. Nonetheless, such automated readings may cause alarm.

Methods:
We therefore assessed the prevalence and prognostic significance of AER in 238,456 individuals aged 18-75 years. The study was performed at a tertiary medical center serving a racially diverse urban population with a large proportion of Hispanics (43%). The first recorded ECG of each individual during 2000-2012 was included. Patients with ventricular paced rhythm or acute coronary syndrome at the time of acquisition were excluded from the analysis. All automated ECG interpretations were reviewed for accuracy by a board certified cardiologist. The primary endpoint was death during a median follow up of 8.0±2.6 years.

Results:
AER was present in 3,450 (1.6%) subjects. The prevalence varied significantly with race: African Americans 2.2%, Caucasians 0.9%, and Hispanics 1.5% (p<0.01), and sex: male 2.4% vs. female 0.6% (p<0.001). In a Cox-proportional Hazards model (Figure 1) controlling for age, smoking status, heart rate, QTc, systolic blood pressure, LDL-cholesterol, BMI, and CAD, there was no significant difference in mortality regardless of race or sex (RR 0.98 (95% CI: 0.89-1.07). This was true even if J-waves were present.

Conclusion:
The prevalence of AER in Hispanics was intermediate to that of African Americans and Caucasians. This ECG finding was not associated with an increased risk of death, regardless of race or sex, and should not trigger additional diagnostic testing.
Abstract 16011: An Outcomes Assessment of Vasodilator Therapy in Pulmonary Arterial Hypertension Through Meta-Analysis of 31 Randomized Controlled Trials
Authors: Ryan John J , Chatterjee Saurav , Hatton Nathan , Patel Neel , Stehlik Josef , Bucholz Emily , Krumholz Harlan
Published: July 2021

Introduction:
Pulmonary Arterial Hypertension (PAH) is a rapidly progressive disease with high mortality. We reviewed randomized controlled trials (RCTs) to evaluate the effect of pulmonary vasodilators on mortality in PAH.

Hypothesis:
Our objective was to determine the effect of PAH medicines on survival, and the impact of trial design on outcomes.

Methods:
We conducted a meta-analysis using MEDLINE, EMBASE, Cochrane Library, Web of Science, and Scopus (inceptions-May 2014) of all RCTs treating PAH with pulmonary vasodilators. Data on all-cause mortality and hemodynamics were abstracted. Summary relative risks (RR) and 95% confidence intervals (CI) for outcomes were calculated using a random effects model comparing various pulmonary vasodilators with control.

Results:
The analysis included 31 RCTs (6,271 patients, 77% female, range of mean age 30-57 years). Median follow up was 12 weeks (18 trials had ≤ 12 weeks follow up, and only 5 followed patients ≥ 6 months). When analyzed together (n = 14), FDA-approved pulmonary vasodilators demonstrated a mortality benefit with RR = 0.77 (95% CI = 0.60 - 099, I
2
= 0%). When analyzed by vasodilator type, prostacyclins were the only class of agents with significant mortality benefit, RR = 0.61 (95% CI 0.38-0.98, I
2
= 1%). Oral pulmonary vasodilators demonstrated no significant benefit on PAH mortality, RR = 0.85 (95% CI 0.65-1.12, I
2
= 0.0%), but we could not exclude a clinically meaningful benefit or harm. Many studies reported ≤1 death in at least one treatment arm. When we limited the analysis to only studies with at least 2 deaths in both treatment arms (n=9), the mortality benefit for pulmonary vasodilators was no longer significant (RR 0.86, CI 0.66-1.12, I
2
=0%), but the point estimate was below 1 and we could not exclude a reduction or increase in risk. For studies with the shorter follow up of ≤ 12 weeks, the RR of mortality for active treatment arm was 0.54 (95% CI 0.35-0.83), compared to trials with > 12 weeks of follow up where the RR of mortality was not significant at 0.91 (95% CI 0.67-1.22).

Conclusion:
There is an observed mortality benefit for prostacyclins in PAH. For the oral pulmonary vasodilators, there is no observed mortality benefit based on either design of trials, length of follow up or efficacy of the agents studied.