bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 15556: Effects of Left Ventricular Assist Device Support on microRNA Levels
Authors: Wang Teresa , O’Brien Emily , Samsky Marc , Rogers Joseph , Hernandez Adrian , Bowles Dawn , Felker G Michael , Patel Chetan , Ahmad Tariq
Published: July 2021

Objectives:
To examine changes in a broad panel of circulating microRNAs (miRs) following left ventricular assist device (LVAD) support in advanced heart failure (HF).

Background:
LVAD therapy unloads the failing heart and may result in partial reversal of the end stage HF phenotype; however, molecular changes with support have not been well defined. MicroRNAs are small nucleotide RNAs involved in the pathogenesis of HF and have been postulated to have a potential role as circulating biomarkers or as therapeutic modalities. Human studies of the role of miRs in end stage HF have been limited.

Methods:
23 distinct miRs, previously shown to play a role in the pathogenesis of HF, were measured in frozen plasma collected from 40 individuals prior to continuous flow LVAD implantation, and at a median of 96.5 (interquartile range, IQR: 72.25-149.75) days after implantation. Quantitative real-time PCR was performed for miR amplification. Ultimately, 19 miRs (miR-15b, -16, -21, -24, -27a, -29a, -92a, -103, -126, -133a, -146a, -146b, -155, -159a, -195, -221, -222, -320, -423) were expressed in >80% of patient samples. Wilcoxon Rank Sum Tests were used to compare median relative quantification values pre- and post-LVAD placement.

Results:
The median age of patients was 67 years, and 60% were INTERMACS 1-2 prior to LVAD implantation. Following LVAD implantation, seven miRs (miR-21, -92a, -103, -159a, -195, -320, -423) were downregulated while 12 miRs (miR-15b, -16, -24, -27a, -29a, -126, -133a, -146a, -146b, -155, -221, -222) were up-regulated. After correction for multiple testing, only miR-155 was associated with significant up-modulation in plasma expression levels with LVAD support.

Conclusions:
While most plasma levels of miRs associated with cardiovascular pathophysiology remained unchanged with LVAD support, miR-155, which has been shown to play a role in cardiac hypertrophy, was up-regulated. The biological relevance of miR-155 in this setting requires further study.
Abstract 15557: Comparison of 30-day Mortality by Ischemic Times in ST-Elevation Myocardial Infarction Treated With Pre-Hospital Reduced Dose Fibrinolytic Followed by Percutaneous Coronary Intervention versus Percutaneous Coronary Intervention Alone
Authors: Solhpour Amirreza , Chang Kay-Won , Balan Prakash , Sdringola Stefano M , Denktas Ali E , Anderson H. Vernon , Smalling Richard W
Published: July 2021

Introduction:
The current standard treatment for ST-elevation myocardial infarction (STEMI) is primary percutaneous coronary intervention (PPCI). Early reperfusion results in shorter ischemic time (IT) which reduces mortality. In general, fibrinolysis can be initiated earlier than PPCI. For over 7 years we have used a strategy of field evaluation for STEMI using 12 lead ECGs obtained and transmitted by emergency services personnel with over-read by emergency center physicians. Appropriate STEMI patients receive pre-hospital reduced dose fibrinolytic (10 units reteplase) along with aspirin, clopidogrel, and heparin, and are transported to our center for urgent PCI (termed FAST-PCI strategy).

Hypothesis:
Patients with STEMI in FAST-PCI group have lower 30-day mortality rate compared with those in PPCI group.

Methods:
Patients with STEMI at our tertiary center were prospectively included for retrospective analysis. Demographic, clinical, angiographic data and outcomes were investigated. Ischemic time was defined as time from onset of pain to device activation. Patients were divided into groups based on IT (<120, 120-179, 180-239, ≥ 240 minutes). Within each IT group, patients were compared by PPCI and FAST-PCI groups. The primary endpoint was 30-day mortality.

Results:
Between 02/2007 and 12/2013, we treated 1112 STEMI patients of which 551 (49.5%) underwent FAST-PCI and 561 (50.4%) had PPCI. The two treatment groups in each IT interval were well matched for age, cardiac risk factors, left main and left anterior descending artery infarct. Data are shown in the table.

Conclusions:
For STEMI patients who presented with IT < 180 minutes, FAST-PCI had reduced 30-day mortality rate compared to PPCI. However, a mortality difference was not seen in patients with IT ≥ 180 minutes between the two treatment groups. This suggests that in patients presenting within 3 hours of onset of symptoms FAST-PCI may confer an advantage over PPCI.
Abstract 15599: Klf4 Regulates the Extent of Lung Microvessel Endothelial Cell Regeneration
Authors: Perkins Tina , Wary Kishore
Published: July 2021

Rationale:
Transcription factor Krüppel like factor (Klf)-4 might regulate endothelial cell (EC) regeneration; however, the underlying mechanisms are poorly understood.

Objective:
The goal of this study was to delete EC-
Klf4
in a timed manner using the lox-P elements,
Cdh5 (VE-cadherin)
as a promoter to drive the Cre recombinase, and to address the role of Klf4 in adult lung microvessels.

Methods and Results:
After 12 generations of backcrossing, we transferred

Klf4
fl

to a C57BL background. Male
Klf4
fl/+
were crossed with female
Klf4
fl/+
mice to generate
Klf4
fl/fl
(25%) offspring. In the next breeding scheme,
Klf4
fl/fl
mice were crossed with male tg-
Cdh5
CreERT2
(tamoxifen inducible) mice to produce heterozygous
Klf4
fl
::tg-
Cdh5
CreERT2
offspring (100%). I then crossed male

Klf4
fl
::tg-Cdh5

CreERT2
with female
Klf4
fl
::tg-
Cdh5
CreERT2
to produce offspring of
Klf4
fl/fl
::tg-
Cdh5
CreERT2
genotype (25%). Groups of these mice received tamoxifen everyday for 5 days, and on the 10
th
day, (now called
Klf4
ECKO
mice) all mice were sacrificed. To determine the loss-of-EC-Klf4 protein and to examine the phenotypic alterations, lungs were collected, subjected to biochemical and molecular experiments, fixed and stained for microscopic analyses. Tamoxifen treatment decreased EC-Klf4-protein expression significantly in the

Klf4
ECKO

lung, as compared to
Klf4
fl/fl
or tg-
Cdh5
CreERT2
controls.
Klf4
ECKO
lung tissue showed increased recruitment of neutrophils and inflammatory cells. Trichrome staining revealed increased collagen deposition in the
Klf4
ECKO
versus
the control mice. Importantly, I observed decreased lung alveoli (p<0.05 vs control, n=5), hemorrhage in
Klf4
ECKO
mice, compared to the control groups. Anti-CD31 and anti-von Willebrand Factor (vWF) staining showed significant decrease (p<0.5
versus
control) in microvessel densities in the lung.

Summary:
These compelling sets of results predict the ability of endothelial-Klf4 to regulate EC regeneration, and its loss in lung fibrosis.
Abstract 15622: Cost-Effectiveness of Pediatric Heart Transplantation Across a Positive Crossmatch
Authors: Feingold Brian , Webber Steven A , Bryce Cindy L , Tomko Heather E , Park Seo Y , Mahle William T , Smith Kenneth J
Published: July 2021

Introduction:
Allosensitized children listed with a requirement for a negative prospective crossmatch (XM) have a high risk of death awaiting heart transplantation (HTx). Previously we found that acceptance of the first suitable organ offer for these patients, regardless of the possibility of a +XM, results in a survival benefit at all times after listing, including post-HTx. The cost-effectiveness of this strategy is unknown.

Methods:
We used a Markov-state transition model with a 10 yr time horizon to compare survival, costs, and utility (i.e. quality of life) for 2 waitlist strategies for sensitized candidates: requiring a negative prospective XM (WAIT) vs. accepting the first suitable organ offer (TAKE). Model data were derived from OPTN status 1A pediatric HTx listings from 1999-2009, the PHTS and HCUP KIDS databases, and other published sources. We assumed no possibility of a +XM in the wait strategy and that the probability of a +XM in the take strategy was equal to the pre-transplant PRA.

Results:
At base case, TAKE was dominant; it cost less ($122,856) and gained more (1.04) quality-adjusted life-years (QALYs) than WAIT. In sensitivity analyses varying all model parameters individually over clinically plausible ranges, TAKE remained dominant or favored (using a $100,000/QALY cost-effectiveness threshold) except when the probability of HTx for TAKE was <55% over 2 years (base case value 67%). After adjustment of the model so that waitlist probabilities of death and delisting were equal in both strategies (while maintaining the lower probability of HTx associated with WAIT), TAKE remained dominant. WAIT was no longer dominated if mortality after HTx across a +XM was >30%/year (equivalent to median post-HTx survival of <3 yrs); yet even at the extreme assumption of 100% 1-year mortality after HTx across a +XM for TAKE, the wait strategy was not cost effective ($350,097/QALY).

CONCLUSIONS:
Among sensitized status 1A pediatric HTx candidates, we found that taking the first suitable organ offer is less costly and results in greater survival than awaiting HTx across a negative prospective XM. This suggests that HTx should not be denied based on sensitization status alone.
Abstract 15647: Incidence and Outcomes of Hospitalizations Associated With Adverse Effects of Anticoagulation in Therapeutic Use
Authors: Gupta Navdeep , Elixhauser Anne , Bangalore Sripal , Gutterman David D
Published: July 2021

Background:
Over the last ten years there has been a significant increase in anticoagulation use in various conditions. However, trends in incidence and outcomes of adverse events associated with anticoagulation are not well defined.

Methods:
We analyzed patients in the Nationwide Inpatient Sample (NIS) between 2002-2011 with co-diagnosis of adverse effects of anticoagulation in therapeutic use. Primary outcome was trend in hospital admissions with adverse effects from anticoagulation. Secondary outcome was trends in in-hospital mortality.

Results:
During our analysis hospital admissions associate with adverse effects of anticoagulation increased 135.5% from 99,383 in 2002 to 234,046 in 2011. During the same period the number of hospitalizations with patients on long term anticoagulation more than tripled from 422,145 to 1,557,603. The most common probable indications for anticoagulation were atrial fibrillation (50.2%), personal history of venous thrombosis (12.5%) and prosthetic heart valve (7.1%). Clinical patterns of bleeding were gastrointestinal (15.7%), intracranial hemorrhage (2.5%) and gross hematuria (1.5%). Blood transfusion during index hospitalization with adverse effects of anticoagulation increased as well (27.4% in 2002 to 36.0% in 2011, p<0.001). Mortality increased from 5,564 to 12,233 during the same period, an increase of 119%. Age, male sex, metastatic disease, electrolyte abnormality and weight loss were independent predictors of mortality. There was a steady decrease in risk adjusted yearly odds of mortality with time with 2002 as the index year (1.254 in 2003 to 0.716 in 2011).

Conclusions:
Our analysis showed an increasing trend in hospitalizations associated with adverse effects from therapeutic use of anticoagulants. With increasing use of these agents for appropriate guideline recommended indications caution needs to be exercised in patients with increased bleeding risk.
Abstract 15681: Endothelial Dysfunction, Arterial Stiffness and Inflammation Are Associated With Visual Impairment in Diabetic Patients
Authors: Gouliopoulos Nikolaos , Siasos Gerasimos , Moschos Marilita , Tousoulis Dimitrios , Oikonomou Evangelos , Siasou Georgia , Paraskevopoulos Theodore , Konsola Theodosia , Kokkou Eleni , Stefanadis Christodoulos
Published: July 2021

Introduction:
Diabetic Retinopathy (DR) is a complication of diabetes mellitus (DM) leading to deterioration of vision.

Hypothesis:
We investigated the possible association of vascular function and inflammation with visual acuity in subjects with DM.

Methods:
We enrolled 100 consecutive subjects with DM. Patients were divided in those with DR (53 subjects, mean age 68±9) and those with no evidence of DR (NDR) (mean age 66±6). The diagnosis of DR was made by ophthalmoscopy and best-corrected visual acuity (BCVA) was measured in both eyes. A BCVA less than 0.8 was considered as severely impaired. Endothelial function was evaluated by flow mediated dilation (FMD) in the brachial artery and arterial stiffness was evaluated by carotid femoral pulse wave velocity (PWV). C reactive protein (CRP) and interleukin 6 (IL6) levels were measured.

Results:
Patients with DR compared to NDR patients had impaired FMD (3.42±1.08% vs. 5.39±1.47%, p<0.001), impaired PWV (11.10±3.11m/sec vs. 9.02±2.13m/sec, p=0.001) and worse BCVA (p<0.001). Moreover in DM subjects, BCVA was positively correlated with FMD, creatinine clearance, and inversely correlated with PWV, glycosylated hemoglobin levels, C- reactive protein levels, IL6 levels, age and with duration of diabetes mellitus (p<0.01 for all). Interestingly, after adjustment for age, smoking habits and the aforementioned confounders, FMD, IL6 levels, DM duration and male gender were independently associated with BCVA (p<0.05 for all). Moreover, ROC curve analysis revealed that both impaired FMD (AUC=0.79, p<0.001) and PWV (AUC=0.8, p<0.001) have a significant diagnostic ability in detecting diabetic subjects with severely impaired BCVA. More precisely, FMD less than 4.5% has a sensitivity of 90% and a specificity of 60%, while PWV over 10.0 m/sec has a sensitivity of 83% and a specificity of 68%, for the diagnosis of severely impaired BCVA.

Conclusion:
Patients with DR have significantly impaired visual acuity witch is associated with impaired vascular function and inflammation. Moreover, both endothelial function and arterial stiffness were high sensitivity predictors of visual impairment highlighting their potential role on the prevention and management of the complications in diabetes mellitus.
Abstract 15689: Activation of PKR-Like Endoplasmic Reticulum Kinase is Required for Autophagy Stimulation and Cardiomyocyte Survival During Acute Myocardial Ischemia
Authors: Sciarretta Sebastiano , Nagarajan Narayani , Yee Derek , Zhai Peiyong , Umapathi Priya , Brady Christopher D , Volpe Massimo , Frati Giacomo , Sadoshima Junichi
Published: July 2021

PKR-like endoplasmic reticulum (ER) kinase (PERK) is an ER-resident serine/threonine kinase that regulates the cellular response to ER stress and energy deprivation. Under stress, PERK activation can be either protective or detrimental. We studied for the first time whether PERK regulates cardiomyocyte (CM) survival and death during myocardial ischemia, which is characterized by both ER and energy stress.

We found that PERK is significantly activated after 30 minutes of myocardial ischemia (2.4 ± 0.04-fold, p<0.001), as shown by its increased phosphorylation status. After 3 hours of ischemia, mice with cardiac-specific overexpression of dominant-negative PERK (Tg-DN-PERK) displayed a significant increase in infarct size/area at risk with respect to non-transgenic (NTg) mice (66.4 ± 4.1% vs. 38.5 ± 6.8%, p<0.05), indicating that ischemia-induced PERK activation is cardioprotective.

PERK signaling regulates autophagy in cancer cells. Autophagy is an intracellular degradation mechanism that promotes CM survival during ischemia by relieving both energy and ER stress. We found that autophagy activation during ischemia is abrogated in the hearts of Tg-DN-PERK with respect to NTg, as indicated by reduced LC3-II accumulation (0.71 ± 0.05-fold, p<0.01). Consistently, CMs with adenovirus-mediated overexpression of DN-PERK displayed reduced LC3-II accumulation (0.69 ± 0.1-fold vs. control CMs, p<0.05) after 4 hours of glucose deprivation (GD) in vitro, a condition that mimics ischemia-induced energy stress. A similar result was also observed after bafilomycin A1 treatment to test autophagic flux. These data indicate that PERK is required for autophagy activation and flux during CM ischemia and GD.

Finally, we saw that DN-PERK overexpression significantly promotes CM death after GD, as shown by propidium iodide assay (2.01 ± 0.25-fold vs. control CMs, p<0.05). However, co-overexpression of Atg7, which activates autophagy, significantly reduced cell death induced by DN-PERK (-61%, p<0.05). These data suggest that autophagy inhibition partly mediates the detrimental effects of PERK inhibition during energy stress.

In conclusion, our study demonstrates that PERK activation is required for autophagy activation and CM survival during ischemia.
Abstract 15707: Fluorescence Voltage Recordings From Stem Cell-Derived Cardiomyocytes Enable High-Throughput Screening for Cardiotoxicity
Authors: Leyton-Mange Jordan S , Mills Robert W , Jang Min-Young , Ling Xaio , Ellinor Patrick T , Milan David J
Published: July 2021

Introduction:
The lack of high quality predictive models for drug-induced QT prolongation continues to be a significant problem in pharmaceutical development. While human pluripotent stem cell derived-cardiomyocytes (hPSC-CMs) hold promise to be a valuable tool for drug discovery, efforts have been frustrated by the labor-intensive nature of electrophysiological recordings and the heterogeneity of hPSC-CMs populations.

Methods:
Using lentivirus, we introduced the genetically encoded fluorescent voltage reporter, A242-Arclight, into hPSC-CM monolayers in multi-well plates. An inverted fluorescence microscope was fit with an environmentally controlled enclosure and automated stage. High speed imaging with a Photometrics Evolve 128 EMCCD camera was performed at baseline and after administration of test compounds. Optical traces were processed using a custom program and composite AP durations, APD80, were compared before and after drug application (Figures A & B).

Results:
Baseline APD80 values displayed high degree of consistency between wells: 483±59 msec. High-throughput data acquisition demonstrated dose dependent APD80 increases from all QT-prolonging agents tested as well as dose dependent APD80 decrease from pinacidil. In contrast, negative control compounds caused no significant changes in APD80. Results from a representative plate are shown (Figure C).

Conclusions:
Optical measurements provide rapid recordings of drug-induced AP duration changes, and offer a strategy to non-invasively screen hPSC-CMs in high-throughput. Recording from cell monolayers as opposed to single cells and using paired comparisons may be beneficial in addressing the heterogeneity amongst hPSC-CM preparations.
Abstract 15716: Non-Targeted Metabolomic Profiling Identifies Novel Markers of Insulin Resistance
Authors: O’Sullivan John F , Cuthbertson Daniel J , Gerszten Robert E
Published: July 2021

Background:
Targeted metabolomic profiling has identified metabolite classes associated with insulin resistance (IR) and incident metabolic disease, including branched-chain (BCAAs) and aromatic amino acids (AAAs). Emerging non-targeted profiling methods, which facilitate screening of many-fold more metabolites, hold great promise for the identification of additional disease biomarkers and pathways. We developed a non-targeted workflow to determine differentially regulated metabolites in two groups that differed by the homeostatic model assessment of IR (HOMA-IR).

Methods:
We analyzed fasting plasma from subjects with IR (HOMA-IR ≥ 2.6) (mean age = 67 ± 1.49; BMI = 28 ± 0.63; HOMA-IR = 7.94 ± 1.67) and normal subjects (HOMA-IR ≤ 1.85) (mean age = 68 ± 2.42; BMI = 26 ± 0.86; HOMA-IR = 1.13 ± 0.08), using HILIC chromatography coupled to an Agilent™ 6550 iFunnel Q-TOF mass spectrometer operated in positive ion mode. Batch recursive metabolite feature extraction was performed using MH Profinder software followed by differential metabolite analysis and identification using MPP software.

Results:
We identified 56 differentially abundant compounds [p < 0.05; unpaired t-test with Benjamini-Hochberg FDR (B-H FDR) correction] in a derivation cohort (n=15 IR; n=15 control) and validated 28 of these compounds in a similarly sized independent cohort (p <0.05, BH-FDR corrected). As expected, we confirmed compounds known to be associated with IR, including the BCAA valine (p=2.9E-3), the AAA tryptophan (p=1.01E-2), and a hexanoylcarnitine (p=4.8E-2). In addition, we made putative identifications of novel compounds that were significantly elevated in IR subjects in both cohorts, including aminooctanoic acid (+41%, p=3.68E-3), methylhistidine (+92%, p=4.78E-3), and methylinosine (+51%, p=3.29E-2). Novel compounds that were significantly decreased in IR subjects included isovalerylglycine (-48%, p=2.03E-2).

Conclusions:
We have developed a non-targeted metabolite profiling platform and detected novel compounds associated with IR. Future work includes unambiguous identification and quantification of these metabolites using isotope-labeled standards, as well as evaluation of these markers in large, heterogeneous clinical populations.
Abstract 15745: Tenascin-c Levels and Clinical Importance in Pulmonary Arterial Hypertension
Authors: Vuran Ozcan , Kayikcioglu Meral L , Nalbantgil Sanem , Musayev Ogtay , Kemal Hatice S , Mogulkoc Nesrin , Can Levent H , Kultursay Kadir H
Published: July 2021

Background:
Prognostic markers are known to have an important value in guiding treatment of pulmonary arterial hypertension (PAH) which is associated with high mortality and morbidity. The prognostic importance of some biomarkers like BNP has been shown and used in the routine course of PAH. Tenacsin-C (TNC) is a glycoprotein located in the extracellular matrix which has an important role in PAH pathophysiology. However, the clinical relevance of PAH and TNC is unknown. In this study, we investigated the plasma levels of TNC in patients with PAH as a possible prognostic marker.

Methods:
Study population consisted of 45 PAH (29 women, mean age: 32±9 years, 34 with PAH associated with congenital heart disease, 9 idiopathic PAH and 2 chronic thromboembolic pulmonary hypertension) patients who were followed-up in our PAH centre. Twenty age-sex matched healthy subjects served as the control-group. Plasma TNC levels were measured using ELISA-method. All patients were evaluated with transthoracic echocardiography including assessment of right ventricle, six minute walk test, and NT-proBNP levels simultaneously, which are all known to have prognostic value in PAH. Data were comparatively evaluated using appropriate statistical analysis.

Results:
TNC levels in patients with PAH were significantly higher, compared to healthy controls (61.9±20.7 ng/mL versus 12.6±5.6 ng/mL, respectively, p<0.0001). There was no significant relationship between age, gender, and TNC levels. There was a significant positive correlation between TNC levels in PAH group and functional class (rho=0.355, p=0.017) and NT-proBNP (rho=0.5, p=0.001) levels, whereas there was a significant negative correlation between TNC levels and fractional area change (FAC, rho=-0.33, p=0.035) and tricuspid annular plane systolic excursion (TAPSE, rho=-0.495, p=0.006).

Conclusions:
TNC levels are substantially increased in PAH. There is a significant association between TNC levels and parameters with proved prognostic value in PAH, such as functional class, TAPSE, FAC, and NT-proBNP levels. All of these data suggest that TNC levels in patients with PAH may be a new prognostic biomarker. Further prospective studies are needed to confirm this statement.
Abstract 15761: New Onset Atrial Fibrillation After Transcatheter Aortic Valve Implantation: A Pooled Meta-Analysis
Authors: Kanmanthareddy Arun , Reddy Madhu , Koripalli Venkata S , Buddam Avanija , Adabala Nivedita , Janga Pramod , Bickel Trenton , Gutovitz Cory , Bommana Sudharani , Atkins Donita , Lakkireddy Dhanunjaya
Published: July 2021

Introduction:
Atrial fibrillation (AF) after cardiac surgery is associated with increased morbidity and mortality. Data comparing the occurrence of AF after transcatheter aortic valve implantation (TAVI) and surgical aortic valve replacement (SAVR) is unknown.

Methods:
We identified all studies reporting outcomes after TAVI in all available electronic databases. Meta-analysis of all the studies was performed using random effects model to a) evaluate the incidence of AF and b) compare the incidence of AF between TAVI and SAVR.

Results:
The incidence of AF was reported in 7 studies, 5 prospective observational studies and 2 randomized controlled studies. The cumulative event rate for new onset AF at 30 days after TAVI was 0.1 (95% CI; 0.06 -0.17). Three studies reported incidence of AF after TAVI and SAVR. The odds ratio (OR) of developing new onset AF with TAVI compared to SAVR was 0.3 (95% CI; 0.10 - 0.88) at 30 days. One year outcome of new onset AF was reported in only two studies. Although, the incidence of AF was lower in the TAVI group, this did not reach statistical significance (OR 0.7, 95% CI; 0.46 -1.07).

Conclusion:
The incidence of new onset AF after TAVI is 10% within the first 30 days. This risk is 70% lower in patients undergoing TAVI compared to SAVR. The impact of AF after TAVI in terms of stroke, mortality and future recurrences of AF are unknown. Further studies are therefore necessary to study these outcomes.
Abstract 15768: Mitochondria-Targeted DNA Repair Glycosylase Ogg1 Suppresses Early Stage of Atherogenesis in Ogg1 Deficient Mice
Authors: Ruchko Mykhaylo V , Sukhanov Sergiy , Gorodnya Olena M , Rachek Lyudmila I , Danchuk Svitlana D , Delafontaine Patrick , Gillespie Mark N
Published: July 2021

Introduction:
Reactive oxygen species (ROS) play a key role in the development of atherosclerosis. Mitochondria are a main source of endogenous ROS in the cell. Mitochondrial DNA (mtDNA) is sensitive to oxidation and our previous results from cultured cell and intact animal models suggest that increasing mtDNA repair prevents both oxidative mtDNA damage and associated cytotoxicity and cellular dysfunction. Involvement of oxidative mtDNA damage in disorders characterized by chronic oxidative stress has been less thoroughly studied.

Hypothesis:
In the present study we tested the hypothesis that transgenic modulation of Ogg1, a DNA glycosylase mediating the first step in the base excision repair of oxidative mtDNA damage, coordinately regulates atherogenesis in mice fed a high fat diet.

Methods:
Wild type (WT) mice, Ogg1 knock-out (KO) mice and KO mice transgenically overexpressing mitochondria-targeted Ogg1 (KO-Tg) were fed pro-atherogenic Western type diet for 14 weeks and analyzed for mtDNA damage and signs of atherogenesis.

Results:
KO mice fed a high fat diet had increased oxidative mtDNA damage in cardiac tissue, whereas KO-Tg animals did not differ from WT mice (WT: 0.18 ± 0.04; KO: 0.35 ± 0.04; KO-Tg: 0.15 ± 0.01 lesions per 10
4
bp; n=3, P<0.05; quantitative Southern blot analysis). We did not observe significant atherosclerotic plaque formation in the aortic valve of animals from any group; however appearance of fatty streaks, indicative of early plaque development, was more evident in KO mice (WT: 179 ± 20; KO: 384 ± 59 pixels, n=4, P<0.05; immunohistochemistry for Fc receptor - general marker of inflammatory cells). This effect was completely blocked in KO-Tg mice. We found increased number of apoptotic cells in the aortic valve of KO, but not KO-Tg mice (WT: 2.00 ± 0.50; KO: 4.25 ± 0.48; KO-Tg: 2.14 ± 0.85 apoptotic cells, n=4, P<0.05; TUNEL assay).

Conclusion:
Our data demonstrate that Ogg1 deficiency in mice fed a high fat diet leads to increased oxidative mtDNA damage, appearance of fatty streaks and cell apoptosis. In contrast, enhancement of mtDNA repair with mitochondria-targeted Ogg1 reduces fatty streaks formation and apoptosis induced by a high fat diet. These results suggest mtDNA damage and repair could be important targets for atheroprotection.
Abstract 15836: Blood Pressure Control and Subclinical Left Ventricular Dysfunction in Treated Hypertensive Subjects
Authors: Sera Fusako , Jin Zhezhen , Russo Cesare , Lee Edward S , Schwartz Joseph E , Rundek Tatjana , Elkind Mitchell S , Homma Shunichi , Sacco Ralph L , Di Tullio Marco R
Published: July 2021

Background:
Blood pressure (BP) control in hypertensive patients is crucial to reducing the risk of future cardiovascular events and heart failure. Left ventricular (LV) global longitudinal strain (GLS) can detect early subclinical cardiac dysfunction, even when LV ejection fraction (EF) is normal, and is an important prognostic indicator. It is not known whether poor BP control is associated with subclinical dysfunction by GLS, and whether ambulatory BP (ABP) is superior to office BP measurements in this regard.

Methods:
Two-dimensional speckle tracking echocardiography and 24-hour ABP monitoring were performed in 394 treated hypertensive subjects (mean age 72 ± 9 years; 63% women) with LVEF ≥50% from the Cardiovascular Abnormalities and Brain Lesions (CABL) study. Uncontrolled office BP was defined as systolic BP ≥140 mmHg and/or diastolic BP ≥90 mmHg; uncontrolled ABP as mean 24-hour systolic BP ≥130 mmHg and/or diastolic BP ≥80 mmHg. Abnormal GLS was defined as a value above the 95% percentile of healthy normotensive subjects from the CABL cohort.

Results:
Office BP was uncontrolled in 188 subjects (47.7%), and ABP in 162 (41.1%). Agreement between these two categorization was low [kappa = 0.16, 95% confidence interval (CI), 0.06-0.26; concordant classification in only 58.4% of subjects]. Subjects with uncontrolled ABP showed significantly worse GLS compared to those with controlled ABP (-16.3 ± 3.0% vs -17.7 ± 2.9%, p<0.0001), whereas GLS was not significantly different between those with uncontrolled vs controlled office BP (-16.8 ± 3.1% vs -17.4 ± 3.0%, p=0.07). After adjustment for pertinent covariates (age, sex, race-ethnicity, body mass index, diabetes mellitus, coronary artery disease and LV mass index), uncontrolled ABP was associated with a higher risk of abnormal GLS (odds ratio = 2.32; 95% CI, 1.33-4.03; p=0.003), while uncontrolled office BP was not (odds ratio = 1.30; 95% CI, 0.76-2.22; p=0.35).

Conclusions:
Uncontrolled 24-hour ABP is strongly associated with LV subclinical dysfunction in hypertensive subjects with normal LVEF. Assessing BP control with ABP monitoring may refine the risk stratification of treated hypertensive patients for early LV dysfunction.
Abstract 15841: Whole Exome Sequencing and Analysis for Sudden Unexplained Death in the Young: A Case Series
Authors: Narula Nupoor , Tester David J , Paulmichl Anna , Maleszewski Joseph J , Ackerman Michael J
Published: July 2021

Introduction:
Annually, thousands of sudden deaths in individuals under the age of 35 years remain unexplained following a medico-legal autopsy and are termed autopsy negative sudden unexplained death in the young (SUDY). Cardiomyopathies, channelopathies, and metabolic disorders may underlie a significant number of SUDY cases. Previously, we demonstrated that 25% of autopsy-negative SUDY cases had mutations in the 4 major cardiac ion channel genes (
KCNQ1, KCNH2, SCN5A
, and
RYR2
). However, over 100 sudden death-susceptibility genes have been discovered and may be implicated in SUDY.

Objective:
We explored the utility of whole exome sequencing (WES) followed by gene-specific surveillance as an efficient and effective means of performing post-mortem genetic testing in SUDY.

Methods:
Postmortem WES was performed on 14 consecutively-referred white SUDY victims (57% men; average age at death 17.4 ± 8.6 years) using the Agilent SureSelect Human All Exon V4+UTR capture kit and an Illumina HiSeq 2000 sequencer. Following variant alignment (hg19) and annotation, 117 cardiac channelopathy-, cardiomyopathy-, and metabolic disorder-susceptibility genes were surveyed to identify putative SUDY-associated mutations. Potentially pathogenic variants had to be non-synonymous and ultra-rare [i.e. absent in all 3 evaluated exome databases (1,000 Genome Project, the NHLBI GO Exome Sequencing Project, and Exome Chip Design)].

Results:
On average, each SUDY case had 12,758 ± 2016 non-synonymous variants, of which 79 ± 15 localized to the 117 evaluated genes. Overall, 8 unique, ultra-rare variants (7 missense, 1 in-frame insertion) identified in 6 genes (3 in
TTN
; 1 each in
CACNA1C, JPH2, MYH7, VCL, RYR2
) were detected in 7 of 14 cases (50%). Of the 7 missense alterations, 2 (T171M-
CACNA1C
, I22160T-
TTN
) were predicted damaging by 3 in-silico tools.

Conclusions:
Although WES and gene-specific surveillance is an efficient and effective strategy to detect rare, potentially lethal, genetic variants, the accurate interpretation of each variant is daunting. Importantly, rarity, even ultra-rarity, does not equal pathogenicity even when the ultra-rare variant resides within a so-called sudden death-susceptibility gene.
Abstract 15889: C-Terminal Modifications of Akt Kinase Boost Cellular Responses to Insulin by Inhibiting Activation Loop Dephosphorylation
Authors: Chan Tung , Zhang Jin , Tiegs Brian , Yan Linda , Blumhof Brian , Keny Nikhil , Penny Morgan , Li Xue , Armen Roger , Pascal John , Rodeck Ulrich , Penn Raymond
Published: July 2021

Introduction:
The Akt kinase isoforms (Akt1, Akt2 and Akt3) are activated downstream of the insulin receptor, and exert unique effects on cell growth, survival and metabolism. We recently described a novel ATP-dependent "dephosphorylation-resistance cage" in Akt kinases that controls access of cellular phosphatases to dephosphorylate the Akt activation loop (T308 in Akt1).

Hypothesis:
Here, we describe that, when Akt is localized at the cell membrane, intramolecular interactions of Akt C-terminal sequences with the hydrophobic groove of the kinase domain protect the phosphorylated activation loop (pT308 in Akt1) from cellular phosphatases.

Methods and Results:
Charged amino acid replacements of Akt C-terminal phosphorylation sites regulated by MTORC2 (Ser473) and by cyclin-dependent kinase 2 (Ser477) increased phospho-T308 protection from cellular phosphatases regardless of subcellular location. Functionally, these phosphatase-resistant Akt variants were refractory to ceramide-dependent dephosphorylation and amplified insulin-dependent T308 phosphorylation in a regulated fashion (Figure 1).

Conclusions:
Collectively, these results suggest that modulating phosphatase sensitivity of Akt activation loops via C-terminal hydrophobic groove may provide a platform to develop novel Akt agonists.
Abstract 159: Immediate Transnasal Evaporative Cooling During Resuscitation from Cardiac Arrest: The Cool Before Airway Study
Authors: Grave Marie-Sophie , van Tulder Raphael , Nürnberger Alexander , Fykatas Stergios , Sebald Dieter , Sterz Fritz
Published: July 2021

BACKGROUND:
Therapeutic hypothermia is an integral part of the standard resuscitation care. One method to induce therapeutic hypothermia is transnasal evaporative cooling.

PURPOSE/AIMS:
We wanted to demonstrate that transnasal evaporative cooling initiated prior to achieving a protected airway during CPR in an out-of-hospital setting is safe and feasible.

METHODS:
Transnasal evaporative cooling via the RhinoChill® (RC) System (BeneChill Inc. San Diego, CA, USA) was initiated prior to a protected airway after initiating cardiac resuscitation, and was continued until either the subject was declared dead, standard institutional systemic cooling methods were implemented or cooling equipment (oxygen and perfluorcarbone) was empty. The subject was monitored throughout the hypothermia period, and followed until either death or hospital discharge. Clinical assessments and clinically relevant adverse events were documented over this period of time.

RESULTS:
In total 21 patients were included in this trial. Four of them had to be excluded subsequently. One patient had been excluded due to a pre-existing secured airway, the others due to user errors. Finally, 17 patients (f=6; mean age 65.5 years, CI95%: 57.7-73.4) met all the eligibility criteria and were included for further investigation. Device-related adverse events occurred in only two patients, which were mild and had no consequence on the patient’s outcome. One was reversible nose-whitening and the other epistaxis. According to the filed reports of the EMS personnel, no severe technical problems occurred by using the RC device that led to a delay or the impairment of quality of the CPR. The most common observed interruption in the application was a short blockage of the device (n=12). In four cases the bag-valve-mask-ventilation wasn’t possible due to blockage or a sealing lack and in two cases a moderate orificial fluid spraying was observed during chest compressions.

CONCLUSIONS/RECOMMENDATIONS:
Early application of the RC device, during cardiac arrest in the out-of-hospital setting of Vienna, is feasible, safe and easy to handle and does not delay or hinder CPR, or establishment of a secure intubation. For efficacy and further safety data additional studies will be needed.
Abstract 15912: Cardiac I-123 Metaiodobenzylguanidine Imaging Provides the Additional Prognostic Information to the Model for End-Staged Liver Disease in Patients With Chronic Heart Failure
Authors: Hakui Hideyuki , Yamada Takahisa , Morita Takashi , Furukawa Yoshio , Tamaki Shunsuke , Iwasaki Yusuke , Kawasaki Masato , Kikuchi Atsushi , Kondo Takumi , Kawai Tsutomu , Takahashi Satoshi , Ishimi Masashi , Ozaki Tatsuhisa , Sato Yoshihiro , Seo Masahiro , Fukunami Masatake
Published: July 2021

Backgrounds:
Liver dysfunction has a prognostic impact on the outcome of patients with advanced heart failure. A model of end-stage liver disease (MELD) is a robust scoring system of liver dysfunction, and a high score has been shown to be associated with poor prognosis in ambulatory patients with heart failure. In addition, cardiac metaiodobenzylguanidine (MIBG) imaging provides prognostic information in patients with chronic heart failure (CHF). However, the long-term predictive value of combining MELD score and cardiac MIBG imaging in CHF patients has not been elucidated. We sought to investigate whether cardiac MIBG imaging provides additional prognostic information to MELD score in CHF patients.

Methods:
We studied 109 CHF outpatients (NYHA class:2.1±0.6, ischemic origin:52%) with left ventricular ejection fraction27%) had a significantly greater risk of the cardiac events than did those with normal WR for both with high MELD score ([[Unable to Display Character: ]]10) (70% [19/27] vs 31% [4/13], p=0.028, hazard ratio 4.0 [95%CI 1.2-13.6]) and low MELD score (<10) (34%[10/29] vs 8%[3/40], p=0.005, hazard ratio 6.4 [95%CI 1.7-23.2]).

Conclusion:
Cardiac MIBG imaging would provide the additional prognostic information to MELD score for CHF patients.
Abstract 15922: Role of Polo-Like Kinase-1 in Intimal Hyperplasia in Saphenous Vein Graft: Potential Implication in Vein-Graft Disease
Authors: Sur Swastika , Chen Songcang , Sugimoto Jeffrey T , Agrawal Devendra K
Published: July 2021

Coronary revascularization by coronary artery bypass grafting (CABG) is the choice of procedure in patients with multi-vessel or left main coronary artery disease. Concerns have been raised on the long term result of CABG using saphenous vein graft (SVG) as its patency significantly declines following surgery, compared to internal mammary artery (IMA), which is almost immune to restenosis. Proliferation of smooth muscle cells (SMCs) is the key event in the pathogenesis of intimal hyperplasia leading to SVG failure. PDGF-BB is a major growth factor released at the site of pulsatile stretch- and shear stress-induced graft injury. Here, we examined, for the first time, the expression of PLK1 and its phosphorylation/activation in isolated human bypass graft conduits. Human SV and IMA vessels were freshly collected, SMCs isolated and cultured up to 5th passage. In cultured SMCs, effect of PDGF-BB was examined on total and phosphorylated PLK1 (pPLK1) by Western blot analysis. Cell proliferation was measured using thymidine incorporation, MTT method and cell count. We found significantly higher expression of pPLK1 and total PLK1 in PDGF-stimulated SV SMCs than IMA. SV SMCs had 5-fold increase in the density of pPLK1 and had 2-fold increase in the density of total PLK1. While in the IMA SMCs, increase in pPLK1 was significantly lower than in SV SMCs. Also, this increase was not sustained. These data suggest a greater and sustained sensitivity of SV SMCs to PDGF-BB induced PLK1 activity than that of IMA. A PLK1 blocker inhibited PDGF-induced proliferation in both IMA and SV SMCs. These data demonstrate differential activity of PDGF-induced PLK1 activation, which was greater in SV SMCs than in IMA. This could explain the development of intimal hyperplasia in SV conduits than the IMA following CABG. Thus, inhibition of PLK1 could be a target in developing better therapeutic approach to prevent vein-graft disease.
Abstract 15925: Localization of Nav1.5 at the Intercellular Junctions Resolved by Diffraction-Unlimited Microscopy in Three Dimensions and by Correlative Light-Electron Microscopy
Authors: Leo-Macias Alejandra , Agullo-Pascual Esperanza , Rothenberg Eli , Delmar Mario
Published: July 2021

Sodium current amplitude, kinetics and regulation depend on the properties of the pore-forming protein (mostly NaV1.5 in adult heart) and on the specific molecular partners with which the channel protein associates. The composition of the voltage-gated sodium channel macromolecular complex is location-specific; yet, the exact position of NaV1.5 in the subcellular landscape of the intercalated disc (ID), remains unclear. We implemented diffraction unlimited microscopy (direct stochastic optical reconstruction microscopy, or “dSTORM”) to localize the pore-forming subunit of the cardiac sodium channel NaV1.5 with a resolution of 20nm on the XY plane. In isolated adult ventricular myocytes, NaV1.5 was found in distinct semi-circular clusters. When the entire population of clusters within a 500 nm window from the ID was considered (more than 350 individual clusters analyzed), 75% of them localized to N-cadherin rich sites. NaV1.5-distal clusters were found at an average 313±15 nm from the cell end. Introducing an astigmatic lens in the light path allowed us to solve cluster location in three dimensions, at resolutions of 20 nm in XY and 40 nm in the z plane. Three-dimensional images confirmed the preferential localization at or near N-cadherin plaques, and further suggested that NaV1.5 arrives to the membrane via N-cadherin-anchored paths, most likely microtubules. In additional experiments, we developed a novel approach to correlate the image of NaV1.5 clusters by dSTORM with the cellular ultrastructure as resolved by electron microscopy on the same sample. This “correlative light-electron microscopy” method confirmed the preference of NaV1.5 clusters at sites of mechanical coupling. Overall, we provide the first ultrastructural description of NaV1.5 at the cardiac ID and its relation with the major electron-dense domains of the adult heart. Our data support a model by which microtubule-mediated delivery of NaV1.5 anchors at N-cadherin-rich sites, likely “mixed junctions” also containing desmosomal molecules (such as plakophilin-2; see Cerrone et al; Circulation 129:1092-1103, 2014) and connexin43. These findings have major implications to the understanding of sodium current disruption in diseases affecting the integrity of the ID.
Abstract 15931: Glycogen Synthase Kinase-3α Plays a Critical Role in the Development of Cardiac Dysfunction During Obesity and Insulin Resistance Through Phosphorylation of Peroxisome Proliferator-Activated Receptor α
Authors: Nakamura Michinari , Zhai Peiyong , Sadoshima Junichi
Published: July 2021

Obesity and insulin resistance (IR) lead to impaired cardiac metabolism, resulting in cardiac dysfunction. However, the underlying mechanisms responsible for the development of cardiac dysfunction remain poorly understood. PPARα serves as a key regulator of fatty acid (FA) metabolism in the heart. GSK-3α, a serine/threonine kinase, was dephosphorylated at S21 and activated (2.0 fold, p<0.05) in the hearts of obese mice fed a high-fat diet (HFD) and ob/ob mice. To evaluate the functional significance of GSK-3α upregulation, wild-type (WT) and cardiac specific GSK-3α heterozygous knockout (cGSK-3α HKO) mice were fed a HFD for up to 14 weeks. There was no difference in the food intake or body weight change between WT and cGSK-3α HKO mice. However, cardiac hypertrophy and diastolic dysfunction observed in WT mice were significantly ameliorated in cGSK-3α HKO mice after HFD feeding (8.1± 0.6 and 6.5±0.5, LVW/TL; 24.8±0.9 and 16.6±0.8, deceleration time (DT), all p<0.05). FA oxidation (FAO) (0.81 fold) and ectopic lipid accumulation (Oil Red O staining) were significantly decreased in cGSK-3α HKO mice than in WT mice after HFD feeding. GSK-3α, but not GSK-3β, directly interacted with and phosphorylated PPARα at the ligand binding domain in cardiomyocytes (CMs) and in the heart. PPARα phosphorylation in the heart was significantly increased (2.1 fold, p<0.05) in response to HFD, but it was attenuated in cGSK-3α HKO mice (0.74 fold, p<0.05). Fenofibrate, a PPARα ligand, inhibited GSK-3α-induced PPARα phosphorylation (0.81 fold, p<0.05), reduced ectopic lipid accumulation, FAO (0.84 fold, p<0.05), and attenuated diastolic dysfunction (25.5±3.1 and 18.6±2.5, DT; 0.16±0.04 and 0.08±0.02, EDPVR, all p<0.05) in the heart of HFD fed mice. Collectively, these results suggest that GSK-3α increases PPARα activity through phosphorylation of PPARα, which is inhibited by Fenofibrate. Activation of GSK-3α and consequent phosphorylation of PPARα during obesity and IR could play an important role in the development of cardiac hypertrophy and diastolic dysfunction. Synthetic PPARα ligands inhibit GSK-3α-mediated phosphorylation of PPARα, thereby paradoxically attenuating excessive FA metabolism in cardiomyocytes.
Abstract 15948: Impact of Age on Safety of Radiofrequency Ablation in Patients With Atrial Fibrillation
Authors: Elcano Janet W , Pak Hui Nam
Published: July 2021

Background:
The incidence of atrial fibrillation (AF) is increasing in the elderly population, however, there is paucity of data on the safety outcomes of this patient subgroup thus we sought to investigate on the impact of age on the safety of catheter ablation for AF.

Methods and Results:
We included 1,293 (male 75%) patients enrolled in Yonsei AF Ablation Cohort database in Seoul, South Korea, from March 2009 to November 2013. We divided the patients into 4 groups according to age (Group 1, aged 17-49, N=295 ; Group 2 50-59, N=421; Group 3 60-69 N=408; and Group 4 ≥ 70, N=169) and evaluated the incidence of procedure related complications. No procedure-related death occurred in this study. There was a trend of increasing incidence of procedure related complications with age noted as follows: Group 1= 3.7%; Group 2= 4.0%; Group 3=6.6%; and Group 4 7.1%, (p= 0.15). There were 28 cases (2.2%) of major complications (Group 1=1.7%, Group 2=1.9%, Group 3=2%, Group 4 4.1%), tamponade being the most common. Major complications in group 4 include: tamponade 4 cases, phrenic nerve palsy 1 case, atrioesophaeal fistula 1 and 3rd degree AV block in 1 patient. Multivariate regression analysis shows ablation time (odds ratio (OR) 1.2 confidence interval (CI)1.0-1.017, p=0.017), procedure time (OR 1.008, CI 1.0-1.15, p=0.04), decreasing eGFR (OR 1.013, CI 1.002-1.026 p=0.018), coronary artery disease (CAD) (OR 1.847, CI 1.003-3.524, p0.04) and age (OR 1.028, CI 1.003-1.055, p=0.03) were associated with increased adjusted risk of total complications. Predictors of major complications include age (OR 1.044, CI 1.003-1.086, p0.02) and ablation time (OR 1.009, CI 0.999-1.000, p=0.033).

Conclusion:
Our data suggest that incidence of procedural complications in RFA of AF increase with age. Ablation time and age are independent predictors of a major complication.