bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 167: Possible New Application of HTK Solution to Protect Cardiac Arrest--Induced Brain Injury After Cardiopulmonary Resuscitation
Authors: Chen Yih-Sharng , Ma Ming-Chieh
Published: July 2021

Background:
The cardioplegic solution, histidine-ketoglutarate-tryptophan (HTK), is a preservative solution for organ transplantation. Here we tested whether HTK may protect neurons against poor oxygen-induced cell damage and thus alleviate ischemic injury in brain after CA.

Methods:
The CA-mediated brain damage was induced by stop of ventilation for 4 min 30 sec (4’30’’) or 6 min 30 sec (6’30’’), and followed by manual CPR and epinephrine. HTK (200 μl) was given into brain via left carotid arterial catheter after CA. The sterile saline was given as controls. Neurological deficit scoring for motor function and mortality were evaluated on day 0 to 3 during recovery. The neuronal-like NG108-15 cells were applied and exposed to 2% oxygen or H2O2 to induce severe hypoxic (SH) injury or cytotoxicity in the presence or absence of HTK. Cell viability was assayed by the release of lactate dehydrogenase (LDH). Changes in caspase-3 activity for cell death were evaluated.

Results:
Compared with the 6’30’’ CA groups, the 4’30’’ groups had higher survival rates despite either in saline- or HTK-treated rats after 3-day CA (5/8 of 4’30’’ vs. 4/15 for 6’30’’ in saline-treated groups; 6/8 of 4’30’’ vs. 4/9 for 6’30’’ in HTK-treated groups). Neurological scores were significantly improved by HTK on day 1 for the 4’30’’ groups and days 1-3 for the 6’30” group. Most of improvements in the HTK-treated rats were related to increases in level of conscious, corneal reflex, righting reflex, motor coordination, movement activity but not respiration. Compared to the untreated NG108-15 cells, replacement of culture medium with HTK attenuated SH- and H2O2- mediated cytotoxicity in a volume- and time-dependent manner. Interestingly, these effects were associated with reduction of caspase-3 activation.

Conclusion:
These results suggest HTK is also an effective neuroprotective solution to protect neuron against hypoxia and treat CA-induced brain dysfunction via the mechanism of caspase-3 inhibition.
Abstract 16701: Conventional Cardiovascular Risk Modifies Clinical Outcomes Among Subjects With Elevated Coronary Artery Calcium Score With and Without Statin Therapy: Post Hoc Analysis From the St Francis Heart Study
Authors: Waheed Salman , Pollack Simcha , Roth Marguerite , Reichek Nathaniel , Guerci Alan , Cao Jie J
Published: July 2021

Objective:
Coronary artery calcium score (CAC) predicts cardiovascular (CV) risk independent of conventional risk profile. However, it remains unclear how clinical risk profile modifies CV outcomes among subjects with elevated CAC with and without lipid lowering therapy.

Methods:
We conducted a post hoc analysis of the treatment trial of the St. Francis Heart Study_double-blind, placebo-controlled randomized clinical trial of atorvastatin 20 mg, vitamin C 1 g, and vitamin E 1,000 U daily, versus matching placebos in 993 asymptomatic individuals with CAC at or above the 80th percentile for age and gender. Primary CV outcomes included non-fatal MI or coronary death, coronary revascularization, stroke, and peripheral arterial revascularization. Among the placebo and treatment groups, we further stratified by eligibility for statin therapy based on current AHA guidelines yielding 4 subgroups: treated not eligible (+Rx/-E), placebo not eligible (-Rx/-E), treated eligible (+Rx/+E) and placebo eligible (-Rx/+E).

Results:
Mean age was 59±6 years. Those eligible were older (61±5 vs. 56±5 years) and more likely to be males (85% vs. 56%) than those not eligible. Median [IQR] CAC was higher in the eligible than not eligible groups (overall, p<0.0001), 199 [112-396] (+Rx/-E), 207 [114-416] (-Rx/-E), 490 [289-791] (+Rx/+E) and 484 [286-837] (-Rx/+E). After a median follow up of 4.8 years, 4.0%, 4.8%, 9.8% and 15.4% had a CV event in +Rx/-E, -Rx/-E, +Rx/+E and -Rx/+E, respectively. After adjusting for CV risk factors and CAC, hazard ratio (95% CI) was 1.1 (0.4-2.9), 3.3 (1.1-9.4) and 4.9 (1.7-14.0) for -Rx/-E, +Rx/+E and -Rx/+E, respectively compared to +Rx/-E. There was a significant interaction between CAC and eligibility for statin therapy for a CV outcome (p=0.05).

Conclusion:
Among subjects with elevated CAC, those eligible for statin therapy have higher CAC and overall greater risk for a CV outcome than those not eligible. While statin therapy lowers CV risk among those eligible, it does not significantly alter CV risk among those not eligible. There is a significant interaction between CAC and statin therapy eligibility for a CV outcome. Our findings suggest that clinical risk profile remains an important risk modifier for CV outcomes among those with elevated CAC.
Abstract 16708: Cathelicidin Related Antimicrobial Peptide Treated Bone Marrow Derived Mononuclear Cells Improves Cardiac Function in a Mouse Model of Acute Myocardial Infarction: Potential Therapeutic Targets in Ischemic Heart Disease
Authors: Klyachkin Yuri M , Nagareddy Prabhakara R , Asfour Ahmed , Ye Shaojing , Gao Erhe , Annabathula Rahul V , Abdel-Latif Ahmed
Published: July 2021

Introduction:
Limited stem cell retention following intracoronary administration for ischemic heart disease has reduced the clinical efficacy of this novel therapy. Cathelicidins have been shown to prime BMMNC migration towards low gradients of SDF-1 suggesting a potential role in BMMNC retention. We sought to assess the safety and efficacy of BMMNC pre-treatment with CRAMP for treatment of acute ischemic heart disease.

METHODS:
BMMNCs isolated from GFP mice were incubated with recombinant CRAMP (2.5 μg/ml) or placebo for 1 hour followed by chemotaxis studies towards low levels of SDF-1 (2 ng/ml) using a Boyden chamber in vitro. During the in vivo studies, mice were randomized into 3 groups: AMI followed by injection of phosphate buffered saline (PBS), BMMNCs alone, or BMMNCs incubated with CRAMP. Scar size, survival and retention of injected BMNNCs were examined by immunohistochemistry at 5 weeks. Left ventricular function was measured by echocardiography at baseline, 48 hours, and 5 weeks after MI. Changes in infarct size between 5 days and 5 weeks after AMI was assessed by cardiac MRI utilizing delayed gadolinium enhancement.

RESULTS:
Treatment of BMNNCs with CRAMP enhanced their migration towards low, yet physiological, levels of SDF-1 (Fig 1A). In vivo, a greater proportion of cell survival and retention was observed in the BMNNC+CRAMP group than in the BMNNC-alone group (Fig 1B) and this was associated with higher percentage of BrdU positive cells (Fig 1C). Moreover, BMNNC+CRAMP administration led to significantly better survival, improvement of cardiac function (Fig 1D-H) and reduction in infarct size compared with other control groups (Fig 1I).

CONCLUSIONS:
Cathelicidins enhance BMMNC retention after intramyocardial administration for acute ischemic heart disease resulting in enhanced recovery. Therapies employing this strategy may represent an effective method for improving cardiac recovery and survival rate after AMI in human studies.
Abstract 16743: Sauna Bathing, Sudden Cardiac Death and Cause-Specific Cardiovascular Mortality
Authors: Laukkanen Tanjaniina , Khan Hassan , Zaccardi Francesco , Laukkanen Jari A
Published: July 2021

Introduction:
Warm sauna bathing is associated with a better hemodynamic function; however, the association of sauna bathing with fatal cardiovascular outcomes is not known

Hypothesis:
The frequency and duration of sauna bathing may be related to the risk of sudden cardiac death (SCD), fatal coronary heart disease (CHD) and cardiovascular disease (CVD) events.

Methods:
This study is based on 2323 (42 to 60 years) participants from the Kuopio Ischemic Heart Disease risk factor study, which is a population-based sample of men from Eastern Finland. During median follow-up of 20.7 years (interquartile range 18.1-22.6 years), a total of 197 SCDs, 282 fatal CHD and 407 CVD events occurred.

Results:
Frequency, duration, and temperature of sauna bathing were assessed at baseline; 1060 participants reported using sauna once weekly, 1054; 2-3 times per week and 201; 4-7 per week, respectively. After adjustment for conventional CVD risk factors, compared to men reporting 1 sauna per week the hazard ratio (HR) of SCD was 0.87 (95% confidence interval, CI 0.64 to 1.18) for 2-3 sauna/week and 0.46 (95% CI 0.23 to 0.89) for 4-7 sauna/week (p=0.036 for linear trend). Compared to men using sauna 19 minutes per session (highest third) (p=0.002 for linear trend). Similar results were found for the associations between frequency or duration of sauna bathing with fatal CHD or CVD events.

Conclusions:
The frequency and duration of sauna are associated with a substantial reduced risk of SCD, CHD and CVD mortality. Further studies are warranted to define the potential mechanism behind these associations.
Abstract 16764: Locally Produced SAMHD1 Immune Complexes Are Associated With the Development of Idiopathic Pulmonary Arterial Hypertension
Authors: Saito Toshie , Tamosiuniene Rasa , Sharpe Orr , Robinson William H , Nicolls Mark , Rabinovitch Marlene
Published: July 2021

Introduction:
Autoimmunity has been related to the pathophysiology of idiopathic pulmonary arterial hypertension (IPAH). We previously reported 35 IPAH-related antigens identified in immune complexes (ICs) in lungs from IPAH patients. Among these antigens, we validated increased ICs containing SAMHD1, an HIV1 restriction factor, in IPAH vs. donor control lungs.

Hypotheses:
We hypothesized that 1) viruses and/or inflammatory stimuli increase SAMHD1, which is released in exosomes and induces local production of antibodies, 2) SAMHD1 ICs are observed in experimental inflammatory pulmonary hypertension (PH) induced by monocrotaline (MCT) in rats.

Methods:
The viral signature of IPAH vs. control lung tissue was determined by high-throughput sequencing and validated by qPCR. Localization of SAMHD1 or SAMHD1 antibodies was determined by immunohistochemistry. Protein expression was analyzed by western blot in lung tissue and in pulmonary arterial endothelial cells (PAEC) stimulated with TNFα. Experimental PH was induced in rats by MCT injection.

Results:
Viral sequencing confirmed by qPCR indicated that only human endogenous retrovirus K5 (HERVK5) was increased threefold in lung tissue from IPAH vs. controls (P<0.05, n=10 per group). The ratio of perivascular SAMHD1 positive cells to total cells was also increased more than twofold in IPAH vs. controls (P<0.05, n=4 per group), with SAMHD1 mainly localized to macrophages and PAECs, consistent with the increase in SAMHD1 by western blot (P<0.05, n=4 per group). SAMHD1 was detectable in exosomes from IPAH plasma, explaining how it might be released from cells. SAMHD1 recombinant protein was captured in tertiary lymphoid tissue in IPAH lungs, suggesting that specific SAMHD1 antibodies were produced locally. An inflammatory stimulus (TNFα) caused a twofold increase in SAMHD1 in PAECs by western blot (P<0.05, n=3 per group). A similar increase in SAMHD1 ICs was observed in lung tissues from MCT vs. control rats (P<0.05, n=7 and 6, respectively).

Conclusions:
Our data suggest that human endogenous retroviruses or inflammatory stimuli (TNFα) can increase SAMHD1, inducing local ICs and chronic inflammation associated with the pathological changes causing experimental and clinical PH.
Abstract 16767: Exosomes Mediate Heat Shock Protein 27 Athero-Protective Signalling
Authors: Shi Chunhua , Zhang Yuan , Chen Yongxiang , O’Brien Edward R
Published: July 2021

Introduction:
Exosomes represent a discrete population of nano-vesicles secreted by a variety of cells and may contain unique protein cargo that play a role in inter-cellular signalling. We previously showed (ATVB 2009, JACC 2013) that membrane-like vesicles mediate the release of the novel biomarker and athero-protective agent, Heat Shock Protein 27 (HSP27), however did not explore downstream signalling effects of HSP27-laden exosomes.

Hypothesis:
Monocyte derived exosomes facilitate the transfer of HSP27 to human aortic endothelial cells (HAEC) and THP-1 MΦ to elicit athero-protective signalling effects.

Methods:
Exosome particles were purified from conditioned medium of THP-1 monocytes. As we previously showed that HSP27 athero-protection involves activation of NF-kB (e.g., with resultant changes in the expression of key athero-protective genes) we sought to determine if exosomes alter NF-kB signalling, as well as augment the internalization of HSP27 into cells as a cell membrane receptor for HSP27 is yet to be established.

Results:
Purified THP-1 derived exosomes express the classical exosome biomarkers CD81 and MHC-II. Flow cytometry revealed that 18% and 23% of these exosomes are positive for HSP27 immunolabeling with 10 and 40 μg/ml anti-Hsp27-FITC, respectively. The fraction of positive exosomes dropped to 3% when 40 μg/ml of recombinant HSP27 (rHSP27) was co-mixed with these samples and 10 μg/ml anti-HSP27-FITC, thereby confirming immunolabeling specificity. In contrast, a FITC labeled truncated form of the C-terminus of HSP27 (referred to as rC1-FITC) did not bind to exosomes. Indeed, exogenous rHSP27 bound to exosomes potentiated a ~50% increase of triggered NF-κB signalling (p<0.001) in THP-1 MΦ containing an alkaline phosphatase NF-kB reporter construct, while the truncated form of HSP27 (or rC1) did not (p=0.56). In both THP-1 MΦ and HAEC internalization of rHSP27-FITC into cells improved dramatically after exosome binding (e.g., THP-1: 157% increase, p<0.0001), while rC1-FITC had no effect.

Conclusion:
Exosomes contain HSP27 cargo that provide a novel inter-cellular signalling mechanism for the athero-protective effects of HSP27 by activating NF-kB and facilitating HSP27 internalization into cells.
Abstract 16775: Body Mass Index Predicts Exercise Capacity in Patients With Hypertrophic Cardiomyopathy
Authors: Ball Caroline A , Larsen Carolyn M , Hebl Virginia , Geske Jeffrey B , Ong Kevin C , Siontis Konstantinos C , Olson Thomas P , Ommen Steve R , Allison Thomas G
Published: July 2021

Introduction:
Impaired peak VO2 and obesity are known predictors of morbidity and mortality in Hypertrophic Cardiomyopathy (HCM). The purpose of this study is to determine the degree of exercise impairment due to excess weight in patients with HCM.

Methods:
Adult HCM patients who underwent cardiopulmonary treadmill testing at our tertiary referral center from 2006 - 2012 and had consented to research participation were identified retrospectively. Percent predicted peak VO2 was calculated by the Astrand formula for men and the Jones formula for women which adjust for age and gender. Baseline echocardiographic features obtained within 1 week of exercise testing and % predicted peak VO2 were compared among four groups of patients stratified by body mass index (BMI).

Results:
510 patients were identified, with a mean age at diagnosis of 44.3 ± 16.1 years, 186 (36.5%) female. Mean BMI at the time of cardiopulmonary exercise testing was 29.7 ± 5.3 and 227 (44.6%) patients had a BMI ≥ 30. Overweight and obese patients were older and were more likely to be male than their normal weight peers. However, there was no significant difference in ejection fraction (EF), resting left ventricular outflow tract gradient, right ventricular systolic pressure (RVSP), or septal thickness among the groups. HCM patients show impaired peak VO2 across all BMI groups. While peak VO2 increased progressively across BMI groups consistent with greater O2 demand generated by higher body weight, the adjusted peak VO2 in mL/kg/min fell progressively, indicating progressively greater performance impairment with increasing BMI despite similar degrees of cardiac impairment (p <0.0001) (Table 1).

Conclusion:
Increased BMI is associated with reduced exercise performance in a graded manner in HCM patients independent of cardiac impairment identified on echocardiography.
Abstract 16776: Can We Rely on Patients to Report Rehospitalizations After Acute Myocardial Infarction? Implications for the Design of Future Practical Clinical Studies
Authors: Krishnamoorthy Arun , Peterson Eric D , Honeycutt Emily F , Anstrom Kevin J , Effron Mark B , Zettler Marjorie E , Davidson-Ray Linda , Baker Brian A , McCollam Patrick L , Mark Daniel B , Wang Tracy Y
Published: July 2021

Background:
Few studies have described the accuracy of patient-reported hospitalizations and characterized patients who either under- or over-report hospitalizations.

Methods:
At scheduled interviews 6 weeks, 6 and 12 months after discharge, acute MI patients in the TRANSLATE-ACS study were asked to report any rehospitalizations. Bills from hospitals in the patient’s geographic area and from 12-month queries at the discharging institution were obtained to confirm reported and screen for unreported hospitalizations. We assessed the accuracy of patient-reported hospitalizations with bill validation as the reference. We also examined the characteristics of patients who accurately, over-, or under-reported the number of hospitalizations.

Results:
Among 12,302 acute MI patients, 5,668 patients (46%) reported 8,716 rehospitalizations within the 1 year post-discharge. Only 59% of patient-reported hospitalizations were confirmed by medical bill data (Table). Among the total number of hospital bills collected, 34% were never reported by the patient. Among 5,688 patients confirmed to be rehospitalized, 41% accurately reported the number of hospitalizations, 37% over-reported by a range of 1-12 hospitalizations (median 1) and 22% under-reported by 1-19 hospitalizations (median 1). Compared with accurate reporters, under-reporters were more likely to be female (36% vs. 31%), non-white race (17% vs. 12%), unemployed (67% vs. 54%), non-high school graduate (19% vs. 12%) or to have lower functional status (median EQ5D VAS score 65 vs. 75, p<0.01 for all). Characteristics of over-reporters were more similar to accurate reporters. Clinical risk, as summarized by the ACTION mortality risk score, was not substantially different between groups.

Conclusions:
In a large community-based study, the accuracy of patient-reported hospitalizations was low when compared with validation by medical bills, with patients both under- and over-reporting events.
Abstract 16789: Loss of Endothelial Barrier in Fibrillin-1-Deficient Marfan Mice (mgR/mgR) Results in Severe Inflammation After Adenoviral Gene Therapy
Authors: Seppelt Philipp C , Schwill Simon , Arif Rawa , Weber Antje , Zaradzki Marcin , Richter Karsten , Robinson Peter N. , Wagner Andreas , Ensminger Stephan , Matthias Karck , Kallenbach Klaus
Published: July 2021

Introduction:
Nowadays surgery still remains option of choice for therapy of aneurysm in Marfan syndrome. Aortic tissue of Marfan patients shows elastolysis enhanced by proteolytic activity of Matrix Metalloproteinases (MMPs). In this study we performed adenoviral gene transfer of Tissue Inhibitor of MMP-1 (TIMP-1) in aortic grafts of Fibrillin-1-deficient Marfan mice (mgR/mgR) in order to reduce aortic elastolysis.

Methods:
We performed heterotopic infrarenal transplantation of thoracic aorta in female mice (n=35, n=7/group). MgR/mgR and wild-type (WT) aorta (C57BL/6) was either incubated ex vivo with adenoviral vector coding for human TIMP-1 or ß-Galactosidase (5x10^9pfu/ml) or as control with culture medium. 30 days after surgery overexpression of transgene was assessed by immunohistochemistry (IHC) and collagen in situ zymography (ISZ). Histologic staining was performed to outline elastin breaks, signs of inflammation and Neointimal Index (NI). Endothelial barrier was evaluated with the use of transmission electron microscope (TEM) and perfusion of fluorescent albumin.

Results:
IHC and ISZ revealed sufficient expression of transgene. Severe intimal hyperplasia and distinctive signs of cellular inflammation were solely observed in mgR/mgR aorta after adenoviral transduction (NI: ß-Gal 0.23; TIMP-1 0.43), but not in WT aorta (NI: Native 0.01; TIMP-1 0.00). Compared to native mgR/mgR and TIMP-1 treated WT aorta, NI in TIMP-1 treated mgR/mgR aorta was highly significantly larger (p=0.001; p=0.001). Native mgR/mgR grafts presented with severe elastolysis compared to WT (p=0.001). Regardless of the vector transduced elastolysis in mgR/mgR aorta after adenoviral gene therapy was more pronounced compared to WT aorta (ß-Gal p=0.001; TIMP-1 p=0.001). Albumin diffusion through the endothelial barrier was increased in native mgR/mgR aorta compared to native WT aorta (p=0.037). TEM analysis of mgR/mgR aorta displayed reconstruction of the basement membrane and basolateral space.

Conclusions:
Murine Marfan aortic grafts developed severe inflammation after adenoviral exposure. Fibrillin-1-deficiency is associated with dysfunction of endothelial barrier which could be a target for alternative therapies in Marfan syndrome.
Abstract 16803: Icosapent Ethyl (Eicosapentaenoic Acid Ethyl Ester): Effects on Remnant-Like Particle Cholesterol From the MARINE and ANCHOR Studies
Authors: Ballantyne Christie M , Bays Harold , Braeckman Rene , Philip Sephy , Stirtan William , Doyle Ralph , Soni Paresh N , Juliano Rebecca A
Published: July 2021

Background:
Remnant-like particle cholesterol (RLP-C) represents the cholesterol carried by partially catabolized triglyceride (TG)-rich lipoproteins such as very-low-density lipoproteins (VLDL) in the fasted state and chylomicron remnants in the post-prandial state. Increased RLP-C levels are atherogenic and may increase the risk of atherosclerotic cardiovascular disease. Long-chain polyunsaturated omega-3 fatty acids such as eicosapentaenoic acid (EPA) and docosahexaenoic acid reduce RLP-C levels. Icosapent ethyl (IPE) is a high-purity prescription form of EPA ethyl ester approved to reduce TG levels in patients with severe (>=500 mg/dL) hypertriglyceridemia.

Objective:
To evaluate the effects of IPE on RLP-C levels in patients from the MARINE and ANCHOR studies.

Methods:
MARINE (TG >=500 and <=2000 mg/dL; N=229) and ANCHOR (TG >=200 and <500 mg/dL despite statin control of low-density lipoprotein cholesterol; N=702) were both 12-week, phase 3, double-blind studies that randomized patients to IPE 4 g/day, 2 g/day, or placebo. This analysis assessed the median percentage change from baseline to study end in RLP-C levels compared with placebo. Serum RLP-C was measured with an immunoseparation assay (Polymedco).

Results:
In both the MARINE (n=218 with RLP-C data) and ANCHOR (n=252 with RLP-C data) studies, compared with placebo, IPE 4 g/day (Table) and 2 g/day reduced RLP-C levels. Compared with placebo, the approved IPE dose of 4 g/day also reduced RLP-C to a greater extent in subgroups with higher baseline TG levels, reduced RLP-C in statin-treated patients in the MARINE study, and reduced RLP-C in patients receiving moderate- to high-intensity statins in the ANCHOR study.

Conclusions:
Compared with placebo, IPE reduced RLP-C levels in patients in the MARINE and ANCHOR studies, including significant reductions in RLP-C in hypertriglyceridemic patients with TG >=200 mg/dL or >=500 mg/dL receiving statin therapy.
Abstract 16820: CaMKIIδc Transgenic Mice Develop Spontaneous Ventricular Arrhythmias Which Can Be Suppressed by Inhibition of Late Na+ Current
Authors: Arolfo Maria , Chi Liguo , Zeng Aliya , El-Bizri Nesrine , Brown Joan , Rajamani Sridharan , Belardinelli Luiz , Dhalla Arvinder
Published: July 2021

Introduction:
It has been shown that activated CaMKII can phosphorylate cardiac Na+ channels that leads to an enhanced late Na current (INaL). We hypothesized that enhanced INaL plays an important role in arrhythmogenesis linked to increased CaMKII activity. To test this hypothesis we determined the effect of a selective INaL inhibitor GS-967 on spontaneously occurring ventricular arrhythmias in mice overexpressing CaMKIIδc (TG).

Methods:
TG (n=6) and wild type (WT, n=3) mice at age 8 week (wk) were instrumented with telemetry transmitters to record ECG. ECG were recorded continuously starting 1 wk post- surgery (age 9 wk) until age 19 wk. Incidence and burden of arrhythmias were evaluated at ages 9, 11, 13, 15, 17 and 19 wks using DSI ECG Pro software. At age 17 wk, when arrhythmia burden was relatively stable, mice were treated with a single dose of GS-967 (1 mg/kg, i.p.) or vehicle. After 4 days of washout, the treatment was repeated in a cross-over manner. Arrhythmia burden was quantified over a duration of 15-hours post-treatment. Using patch clamp technique, INaL was measured in ventricular myocytes isolated from both TG and WT mice at 17 wk age.

Results:
Incidence and burden of spontaneous ventricular arrhythmias increased progressively with age in TG mice. Between age 9 and 11 wks, 50% of TG mice had an arrhythmia burden ≥ 5 minutes/24 hours. The incidence increased to 83% at wk 13, 15, 17 and to 100% at 19 wks and the burden increased to 71 ± 35 min/24 hr at 17 wk. A single dose of GS-967 significantly decreased arrhythmia burden from 42.5 ± 9.6 min (treated with vehicle) to 9.4 ± 4.3 min (p<0.05) during a 15-hr period. No arrhythmias were observed in WT mice during the course of the study. INaL was enhanced by more than 2-fold in myocytes isolated from TG mice compared to WT (0.2±0.03 vs. 0.08±0.02 pA/pF, n=16 each, p<0.05). GS-967 caused a concentration-dependent reduction of INaL (50.5±3.4% at 0.3 μM, n=7; and 91±5.2% at 1 μM, n=4).

Conclusions:
This is the first report to show a reduction of spontaneously occurring ventricular arrhythmias by inhibition of INaL indicating a key role for INaL in CaMKII associated arrhythmogenesis.
Abstract 16832: Acute Effects of Adaptive Servo-Ventilation on Diurnal Respiratory Instability Quantified Using Novel Method in Patients With Heart Failure
Authors: Kumagai Naoto , Dohi Kaoru , Takeuchi Tetsushiro , Tanimura Muneyoshi , Sato Yuichi , Sugiura Emiyo , Nakamori Shiro , Fujimoto Naoki , Yamada Norikazu , Nakamura Mashio , Ito Masaaki
Published: July 2021

Introduction:
Various types of abnormal breathing including Cheyne-Stokes respiration are frequently observed in patients with heart failure (HF). Although abnormal breathing is recognized as an indicator of poor prognosis, it has not been quantitatively evaluated. Therefore, we proposed a novel method for quantifying respiratory instability during abnormal breathing in patients with HF, and evaluated acute effect of adaptive servo-ventilation (ASV).

Methods:
Diurnal respiratory waveform during wakefulness was obtained by nasal pressure sensor (SAS-3200, Nihon Kohden) for 15 minutes. Analysis method for respiratory waveform was as follows. The inspiration slope (IS) was calculated as the ratio of the peak inspiratory amplitude over time-interval from peak expiration to peak inspiration, and interquartile ranges (IQR) of all consecutive ISs during 15-min were evaluated (Figure, top). Heart failure patients with abnormal breathing have breath-by-breath change in IS and therefore have high IQR score (e.g., Figure bottom left). Firstly, we compared IQR in five healthy volunteers (age 36 +/- 3) and 16 patients with HF (age 66 +/- 17 years old, NYHA 3.3 +/- 0.6, LVEF 31 +/- 12%). Secondly, we compared IQR in all 16 patients with HF during spontaneous respiration and ASV (e.g., Figure bottom right).

Results:
IQR in healthy volunteers were significantly lower compared with patients with HF (0.11 +/- 0.05 vs. 0.29 +/- 0.15, p<0.01). In patients with HF, ASV reduced IQR (0.29 +/- 0.15 vs. 0.14 +/- 0.10, p<0.01 vs spontaneous respiration).

Conclusions:
This novel method effectively quantified respiratory instability in HF patients. This quantitative evaluation method of respiratory instability may become one of the heart failure management tools.
Abstract 16870: Dissociation of Mitochondrial HK-II Triggers Mitochondria Specific Autophagy
Authors: Miyamoto Shigeki , Roberts David J , Tan-Sah Valerie P
Published: July 2021

Introduction:
There is emerging evidence that the metabolic pathway interplays with the survival pathway to preserve cellular homeostasis. Hexokinases (HKs) catalyze the first step of glucose metabolism and hexokinase-II (HK-II) is the predominant isoform in the heart. Our recent study revealed that HK-II positively regulates general autophagy in the absence of glucose. Mitochondrial HK-II (mitoHK-II) is regulated by Akt and provides cardioprotection while it is decreased in the ischemic heart.

Hypothesis:
We tested the hypothesis that mitoHK-II dissociation triggers mitochondria specific autophagy (mitophagy).

Results:
As previously reported, mitoHK-II levels were decreased by ~40% in the perfused mouse heart subjected to global ischemia and in neonatal rat ventricular myocytes (NRVMs) subjected to simulated ischemia. To assess the role of mitoHK-II dissociation, mitoHK-II dissociating peptide (15NG) was expressed in NRVMs. MitoHK-II was decreased by 40% in NRVMs expressing 15NG which was accompanied with Parkin translocation to mitochondria and ubiquitination of mitochondrial proteins. This response was attenuated by Parkin knockdown and reversed by the recovery of mitoHK-II by co-expression of HK-II but not by that of mitochondria binding deficient mutant. 15NG expression did not induce mitochondrial membrane depolarization nor PINK1 stabilization at mitochondria, suggesting that the effects of mitoHK-II dissociation is not dependent on the previously established mitochondria depolarization/PINK1 pathway. This was confirmed by the experiments using PINK1 siRNA. Modest dissociation of mitoHK-II (by 20%) did not induce mitophagic responses but remarkably enhanced FCCP induced mitophagy, indicating that these two pathways are synergetic. We will be analyzing 15NG transgenic mice generated in our lab to determine the mitophagic role of mitoHK-II dissociation in vivo.

Conclusions:
These results suggest that mitoHK-II dissociation can regulate Parkin dependent mitophagy, in conjunction with depolarization dependent mechanisms and that HK-II could confer cardioprotection by switching the cell from an energy production to an energy conservation mode under ischemia.
Abstract 16929: Are Patients Implanted with a Ventricular Assist Device as Destination Therapy Created Equal? Analysis of Outcomes by Implant Indications
Authors: Maltais Simon , Davis Mary E , Haglund Nicholas A , Schirger John A , Aaronson Keith , Pagani Francis D , Stulak John M
Published: July 2021

Introduction:
A growing number of patients are implanted with a continuous-flow left ventricular assist device (CF-LVAD) for destination therapy (DT).

Hypothesis:
We sought to determine if indication for DT was associated with adverse events and survival.

Methods:
Between May 2004 and May 2014, 211 patients (age 66 (19-82), 89% male) underwent implantation of a HeartMate II CF-LVAD. The cohort was stratified according to primary listed indication for DT at time of implant: Group 1=advanced age (n=124, 59%); Group 2=high BMI (n=33, 16%), and Group 3=end-organ comorbidities (n=54, 25%). DT patients who later became BTT were eliminated for homogeneity.

Results:
Follow-up was available in all patients for a total of 376 patient-years of support (median 1.4 years). Preoperative characteristics (creatinine 1.5, INTERMACS 3, IABP 49%) were comparable between groups (all p>0.05). Overall 1, 3 and 5-year survival was 81%, 58%, and 41%, respectively. Kaplan-Meier analysis revealed comparable survival between groups stratified by DT indications (Figure, p=0.07). While gastrointestinal (GI) bleeding was more frequent in patients implanted for advanced age DT indications (p=0.01, group 1 vs group 2 and 3), the incidence of adverse events (pump thrombus/exchange, stroke) was comparable between groups. After adjusting for covariates (creatinine, hemoglobin, prior sternotomy and diabetes), Cox regression analysis demonstrated only preoperative renal dysfunction (HR 1.86 CI 1.28, 2.69; p=0.001) and lower Hemoglobin (HR 0.82 CI 0.71, 0.95; p=0.008) were associated with late mortality after implantation.

Conclusions:
Advanced age remains the most frequent contemporary indication for DT in patients undergoing CF-LVAD implantation. Indication for DT implantation does not influence long-term survival. Elderly patients may be at greater risk of GI bleeding events. These results continue to favor a uniform selection process across the spectrum of DT indications.
Abstract 16993: An Antisense Inhibitor of Apolipoprotein C-III Significantly Decreases Nonesterified Fatty Acid Levels in Severe Hypertriglyceridemic Patients
Authors: Alexander Veronica , Brisson Diane , Flaim JoAnn , Hughes Steve , Singleton Walter , Geary Richard , Gaudet Daniel
Published: July 2021

Background:
Apolipoprotein C-III (apoC-III), a CV risk factor, plays a pivotal role in regulating plasma triglyceride (TG) levels. Elevated TG and its nonesterified fatty acid (NEFA) derivatives are associated with insulin resistance and type 2 diabetes. ISIS-APOCIII
Rx
selectively inhibits apoC-III protein synthesis in the liver and studies show it may improve insulin sensitivity in patients with type 2 diabetes. Treatment with ISIS-APOCIII
Rx
results in significant dose-dependent decreases in apoC-III and TG levels (Table) in patients with severe hypertriglyceridemia (SHTG) as monotherapy or add on to a stable dose of fibrate. The present study assessed the potential resulting change in NEFA levels in these patients.

Methods:
Adult patients with SHTG treated or untreated with fibrate were enrolled in a double-blind Phase 2 study to receive ISIS-APOCIII
Rx
(up to 300 mg) or placebo as weekly SC injections for 13 weeks. Baseline and end-of-treatment fasting serum samples were analyzed for NEFA levels.

Results:
Results show significant reductions in NEFA levels in line with reductions in TG levels at the 300 mg/week dose (the Phase 3 dose) of ISIS-APOCIII
Rx
(Table). ISIS-APOCIII
Rx
was generally safe and well tolerated. There were no clinically meaningful changes in liver tests or other laboratory values.

Conclusions:
Treatment with ISIS-APOCIII
Rx
reduces NEFA levels together with decreases in TG in patients with treated or untreated SHTG suggesting the potential for improvement in peripheral insulin sensitivity in these patients.
Abstract 17053: Prediction of Cardiovascular Disease in the Framingham Offspring Study
Authors: Schaefer Ernst J , Asztalos Bela F , White Charles C , Ai Masumi , Otokozawa Seiko , Nakajima Katsuyuki , Horvath Katalin , Wilson Peter W , Cupples L Adrienne
Published: July 2021

Introduction:
Cardiovascular disease (CVD) is a leading cause of death and disability. Risk factors for CVD have been defined by the recent cholesterol guidelines panel as male gender, and increased age, blood pressure, and total cholesterol, as well as blood pressure treatment, current cigarette smoking, diabetes, and decreased high density lipoprotein (HDL) cholesterol. Our goal was to develop an improved model for predicting CVD risk over 10 years in middle aged male subjects in order to be able to identify high risk subjects.

Methods:
Using plasma or serum samples obtained from male subjects after an overnight fast who were participants in cycle 6 of the Framingham Offspring Study, we measured: C reactive protein (CRP), high density lipoprotein cholesterol (HDL-C), triglycerides, total cholesterol, direct low density lipoprotein cholesterol (LDL-C), small dense LDL-C (sdLDL-C), lipoprotein(a), and apolipoprotein (apo) A-I content of HDL particles as separated by two dimensional gel electrophoresis. Blood pressure, body mass index, waist circumference, history of diabetes, and use of blood pressure, cholesterol, and glucose lowering medications was also assessed. Follow-up information including CVD status over a median of 12.3 years was available for 1,083 men, mean age 59 years and without CVD at onset, of whom 207 (19.1%) developed CVD. A model was developed to predict new onset CVD using only those variables that provided significant information in a stepwise logistic regression analysis to calculate the area under the curve (AROC) and C statistic.

Results:
The following variables entered the model and provided an overall C statistic of 0.73: 1. age, 2. blood pressure treatment, 3. Lp(a), 4. sdLDL-C, 5. ApoA-I in large α-1 HDL, 6. smoking, and 7. diabetes. This model was significantly superior to a model using the standard risk factors or one also using CRP (C statistic 0.68).

Conclusions:
Our data indicates that the measurement of LDL and HDL subfraction and Lp(a) provides significant additional information about CVD risk as compared to standard risk assessment which assesses only total cholesterol and HDL-C.
Abstract 17064: Frailty Predicts Mortality and Hospital Readmission Amongst Elderly Heart Failure (HF) Patients Discharged From Hospital or the Emergency Department (ED)
Authors: Rampersad Penelope , Bronskill Susan E , Chong Alice , Austin Peter C , Tu Jack V , Lee Douglas S
Published: July 2021

Introduction:
Frailty is commonly encountered in elderly patients with HF. However, the impact of both frailty and HF on outcomes in the population has not been delineated. There is a need for operationalizable definitions of frailty to explore variations in care among the elderly.

Objective:
To assess common indicators of frailty as predictors of mortality and rehospitalisation within 1 year in a population-based study of very elderly HF patients.

Methods:
Community-dwelling HF patients aged >75 yrs discharged from hospital or ED in Ontario, Canada, were studied using the Enhanced Feedback for Effective Cardiac Treatment and Emergency HF Mortality Risk Grade databases. Surrogates of frailty, including dementia, falls, incontinence, immobility, caregiver dependence, and abnormal weight loss, were identified from chart abstraction and linked hospitalization records. Survival analyses were performed using multiple Cox regression, for frail vs non-frail status and for each frailty component.

Results:
9964 patients were identified (age 84±5 yrs). After adjustment for age, sex, vital signs, laboratory variables, and comorbidities, presence of any frailty indicator was associated with mortality: adjusted hazard ratio [HR] 1.18 (95%CI; 1.06-1.32, p=0.003). Frailty increased the risk of readmission and the association was more pronounced than for mortality (see
Figure
): adjusted HR 1.29 (95%CI; 1.18-1.41, p<.001). Among the individual frailty components, significant predictors of mortality were: dementia (HR 1.49, 95%CI; 1.34-1.64, p<.001) and care provider dependency (HR 1.17, 95%CI; 1.01-1.36, p=0.038). In contrast, other frailty components increased the risk of readmission, specifically: falls (HR 1.17, 95%CI; 1.06-1.29, p=0.003) and incontinence (HR 1.64, 95%CI; 1.18-2.29, p=0.004).

Conclusion:
Frailty indicators derived from clinical and administrative data sources are associated with death and readmission in a very elderly HF cohort.
Abstract 17097: Acute Inflammation is Required for Regenerative Response in the Neonatal Mouse Heart
Authors: Han Chunyong , Nie Yu , Lian Hong , Liu Rui , He Feng , Hu Shengshou
Published: July 2021

Introduction:
The neonatal mouse heart retains regenerative ability up to 1 week after birth. The regenerative response is characterized by increased cardiomyocyte proliferation following apical resection. However, the mechanisms involved in the reactive cardiomyocyte proliferation are largely unknown. We hypothesized that the acute inflammation was required to activate the regenerative response.

Methods and Results:
We induced sterile inflammation through apical intramyocardial microinjection of zymosan A. Similar to apical resection, zymosan A led to a significant increase of expression levels of inflammatory markers(il6,il1b and ccl3) and number of infiltrating Gr-1(1A8)+ neutrophils demonstrated by realtime PCR and immunofluorescence, whereas at the same time there were no apparent effects on cell viability and tissue integrity. To test whether the induced inflammation led to incresed cardiomyocyte proliferation, we performed the double immunostaining for Ki67 or pH3 and α-actinin. We found a significant increase of proliferating cardiomyocaytes in zymosan A injected hearts relative to PBS injected hearts 4 and 7 days after injection. We also detected a significantly increased Brdu+ cardiomyocytes in zymosan A injected hearts relative to PBS injected hearts 21 days after injection. To explore whether the inflammation was necessary for the regenerative response, we immunosuppressed the mice of resected hearts by administering the anti-inflammatory drug dexamethasone(Dex). Realtime PCR(il6,il1b and ccl3) and immunofluorescence (Gr-1(1A8)) confirmed the immunosuppression effect, while there were no effects on body weight, cardiomyocyte size and cell viability. We found apparently decreased number of Ki67 or pH3 positive cardiomyocyes in apical resected and Dex treated mice compared to resected and PBS treated mice. Moreover, the resected and Dex treated mice hearts displayed a significantly decreased Brdu+ cardiomyocytes 21 days after resection. Next, we found the apical resected and Dex treated mice cannot regenerate their hearts after 21 days, even 5 weeks after injury.

Conclusion:
our results indicated the acute inflammation was required for regenerative response in 1-day-old mouse heart.
Abstract 17131: Diastolic Dysfunction in Asymptomatic Patients With Moderate to Severe Aortic Regurgitation is Strongly Related to Increased Longitudinal Fiber Stress and Subsequent Non-uniform Myocardial Relaxation
Authors: Urheim Stig , Broch Kaspar , Kunszt Gabor , Massey Richard , Aakhus Svend , Gullestad Lars
Published: July 2021

Introduction:
Diastolic dysfunction in aortic regurgitation (AR) is present at an early stage of the disease. Yet, the mechanisms are not clearly understood.

Hypothesis:
We hypothesized that diastolic dysfunction in AR patients is caused by increased longitudinal (meridional) fiber stress and subsequent impaired relaxation of the corresponding subendocardial (longitudinal) fibers.

Methods:
Thirty asymptomatic patients with moderate to severe aortic regurgitation (AR) and 17 age matched healthy controls (C) where analyzed (32 ± 7 and 35 ± 4 (SD) years, respectively, p=NS) with 3D speckle tracking echocardiography. We measured early diastolic longitudinal- (LSRe) and circumferential (CSRe) strain rate (1/s) as the time derivative of strain (%) and the peak difference (LSRe – CSRe) during isovolumic relaxation (IVR). Early diastolic flow rate (sec
-1
) was estimated as the time derivative of the LV volume curve normalized to end-diastolic volume (EDV). Finally, we calculated end-systolic meridional fiber stress (mmHg).

Results:
LV ejection fraction in C and AR was 61 ± 2 and 62 ± 3 %, respectively (p=NS). AR patients had signs of impaired LV filling with lower early diastolic flow rate (Table 1). During IVR, the strain rate curves consistently departed (Figure 1, arrow), indicating a non-homogenous relaxation. A negative correlation was shown between meridional fiber stress and the IVR strain rate gradient (y= -0.0123x + 1.0921, r=0.61, p<0.001).

Conclusions:
We have demonstrated a non-homogenous relaxation of subendocardial- relative to circumferential fibers in AR patients that strongly correlated with longitudinal fiber stress, suggesting a causal relationship.
Abstract 17154: Cardiopulmonary Exercise Testing and Prognosis in HFpEF: the Henry Ford HospITal CardioPulmonary EXercise Testing (FIT-CPX) Project
Authors: Brawner Clinton A , Shafiq Ali , Aldred Heather A , Hassan Raakesh , Vasko Stephanie , Saval Matthew A , Ehrman Jonathan K , Selektor Yelena , Tita Christina , Valez Mauricio , Williams Celeste T , Lanfear David E , Keteyian Steven J
Published: July 2021

The prognostic utility of cardiopulmonary exercise testing (CPX) in patients with heart failure and reduced ejection fraction (HFrEF) has received much attention. However, there are limited data on the value of CPX in patients with HF and preserved EF (HFpEF).

Purpose:
Among patients with HFpEF, describe the association between select CPX measures and prognosis for the composite endpoint of mortality, left ventricular assist device (LVAD), or cardiac transplant (CT).

Methods:
Patients with a CPX between 1997 and 2010 and confirmed HFrEF (EF ≤ 40%; n= 1,201) or HFpEF (EF ≥ 50%; n= 192) were identified. Patients with HFpEF (n= 189, age= 54 ± 14 y, 43% female, EF = 56 ± 5%) were matched (propensity score) to patients with HFrEF (n= 189, age= 54 ± 13 y, 43% female, EF = 22 ± 9%) based on age, gender, history of coronary artery disease, and body mass index. Endpoint data was obtained through 2011. The association between select CPX measures and the endpoint was assessed using Cox regression with adjustment for age, gender, EF, and beta-blocker therapy.

Results:
There were 53 events (28%; median follow-up = 5.1 y) among the HFpEF group and 88 events (47%; median follow-up = 3.6 y) among the HFrEF group. Results from the Cox regression analyses are shown in the Table. Percent predicted peak VO
2
was one of the best predictors of the endpoint in both HFpEF and HFrEF with similar hazard ratios. Although significantly related to the endpoint among HFrEF, V
E
-VCO
2
slope and peak P
ET
CO
2
were not significant among HFpEF.

Conclusions:
These data support the use of % predicted peak VO
2
to risk stratify patients with HFpEF and suggest that the prognostic utility of some CPX measures developed in HFrEF may not be relevant in HFpEF. Additional research is needed to define the association between CPX measures and prognosis specifically for patients with HFpEF.
Abstract 17158: Intraoperative Electroanatomical Mapping and Histopathological Examination Revealed Mechanism of Monomorphic Ventricular Tachycardia associated with Primary Cardiac Tumor
Authors: Murata Hiroshige , Miyauchi Yasushi , Nitta Takashi , Takahashi Kenta , Tsuboi Ippei , Hayashi Hiroshi , Uetake Shunsuke , Yodogawa Kenji , Iwasaki Yu-ki , Hayashi Meiso , Sakamoto Shun-Ichiro , Kunugi Shinobu , Shimizu Wataru
Published: July 2021

Introduction:
Ventricular tachycardia (VT) associated with a primary cardiac tumor is extremely rare. Complete resection of a tumor was reported to be effective in a treatment of this VT. However, the mechanism of the cardiac tumor-related VT (CT-VT) is still unknown, and the therapeutic strategy of the VT in patients with unresectable tumor is not determined.

Methods and Results:
Four patients (20 ± 15 years, 3 males) with CT-VT (fibroma in 2, lipoma in 1, and hemangioma in 1 patient) were investigated. All four patients developed repetitive forms of monomorphic VTs, which were reproducibly induced by programmed ventricular stimulation and terminated by burst pacing. These VTs exhibited a right bundle branch block QRS morphology (QRS duration, 160 ± 28 ms) with a pseudo-delta wave (75 ± 10 ms) at a cycle length of 330 ± 86 ms. Intraoperative electroanatomical mapping showed a radially spreading activation pattern originating from the epicardial border of the tumor, where fractionated and late potentials were detected during sinus rhythm. Histopathological studies of the sections from this border area revealed tumor infiltration to the surrounding myocardium and myocardial cell disorganization exhibiting myocardial disarray. In 2 patients in whom the cardiac tumor was completely resected, cryoablation was added to the resection line. In the remaining 2 patients in whom complete resection of the tumor was unfeasible, encircling cryoablation to entirely isolate the unresectable tumor was effective in suppressing their VTs.

Conclusions:
The mechanism of CT-VT is reentry localized at the epicardial border of the tumor. Myocardial disarray associated with infiltration of the cardiac tumor may be a substrate of this VT. Encircling cryoablation along the border of the tumor may be a therapeutic option for an unresectable CT-VT.