bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 1444: Overexpression Of Endothelial Nitric Oxide Synthase Restores Post-natal Neovascularization In Atherosclerosis.
Authors: Mees Barend , Waeckel Ludovic , You Dong , Tempel Dennie , Godinho Maria , Van Haperen Rien , Lévy Bernard , de Crom Rini , Silvestre Jean-Sébastien
Published: July 2021

Alteration in post-ischemic neovascularization is a common complication of atherosclerotic disease. This results, at least in part, from abrogation of bone-marrow mononuclear cells (BM-MNC) pro-angiogenic potential. Overexpression of eNOS has been shown to promote vessel growth in the setting of ischemia. We hypothesized that eNOS overexpression could restore impaired neovascularization in atherosclerotic (ApoE KO) mice. Hind limb ischemia was induced in mice by right femoral artery ligation. After two weeks we evaluated tissue perfusion of the foot by Laser Doppler, vessel density in the hind limb by micro-angiography and histology, and atherosclerotic plaque size. In vitro BM-MNC cell culture assays were performed. Tissue perfusion and vessel density were 1.5-fold increased in transgenic mice overexpressing eNOS (eNOStg) as compared to wild type (WT) (P<0.001, n=10). Transplantation of 1x106 WT- or eNOStg BM-MNC in WT recipients caused a 1.5-fold increase in tissue perfusion and vessel density compared to injection of PBS (P<0.001, n=10). Next, we used ApoE KO mice and crossbreeds of eNOStg and ApoE KO mice (eNOStg*ApoE KO). Tissue perfusion and vessel density were 1.8-fold increased in eNOStg*ApoE KO mice as compared to ApoE KO mice (P<0.001, n=10). Transplantation of both WT- or eNOStg*ApoE KO BM-MNC in ApoE KO recipients caused a 1.6- to 2-fold increase in tissue perfusion and vessel density compared to PBS (P<0.01, n=10), while transplantation of ApoE KO BM-MNC had no positive effect on neovascularization. Moreover, transplantation of WT BM-MNC significantly increased plaque size, while eNOStg*ApoE KO BM-MNC had no effect on plaque size. eNOS overexpression did not affect BM-MNC apoptosis and secretion of growth factors but increased their ability to differentiate in vitro into EPC.

Conclusion: eNOS overexpression in the endothelium improves post-ischemic neovascularization in both physiological as atherosclerotic settings. Furthermore, eNOS overexpression in the bone marrow restores the impaired pro-angiogenic potential of atherosclerotic BM-MNC without adverse effects on plaque size. Therefore, overexpression of eNOS could play a vital part in the development of therapeutic angiogenesis for atherosclerotic disease.
Abstract 1446: Central Role of Calcium-Dependent Tyrosine Kinase PYK2 in eNOS-Mediated Vascular Function and Angiogenic Response -Unmasked by PYK2 Knockout Mice-
Authors: Matsui Akihiro , Okigaki Mitsuhiko , Katsume Asako , Matsunaga Shinsaku , Yamada Hiroyuki , Matsubara Hiroaki
Published: July 2021

Background:
Endothelial nitric oxide synthase (eNOS) is activated by PI3-kinase/Akt or Ca
2+
-dependent CaM kinases, whereas the involvement of Ca
2+
-dependent tyrosine kinase PYK2 remains to be determined.

Methods and Results:
We newly generated the PYK2-deficient (−/−) mice and investigated the effects of PYK2 on NO-mediated vascular functions and angiogenic response. The PYK2−/− mice exhibited a significant reduction in the basal eNOS phosphorylation and VEGF- or Acetylcholin-mediated response in the aorta and aortic endothelial cells (ECs) compared with the wild-type mice, and blood flow recovery and neovessel formation after hindlimb ischemia were reduced with affecting mobilization of endothelial progenitors. Acetylcholin-mediated aortic vasorelaxation and cGMP production were decreased (54% and 44%, P<0.01, respectively) and blood pressure in the PYK2−/− mice is higher than the wild-type mice (mean 97 vs. 86 mmHg, P<0.05). In the PYK2−/− mice, VEGF-mediated Akt phosphorylation, NO production and cytoplasmic Ca
2+
mobilization were markedly decreased. And also the phosphorylation of c-Src and PLCγ1, interaction of c-Src/PLCγ1 were clearly reduced. VEGF-dependent migration, tube formation and actin cytoskeletal reorganization were markedly inhibited in PYK2−/− ECs, while addition of L-arginine or cGMP-dependent kinase activator reversed the attenuated response.

Conclusion:
These findings demonstrate that PYK2 is involved in the receptor-activated signaling events leading to the phosphorylation of eNOS and thus regulates eNOS-mediated vasoactive function and angiogenesis.
Abstract 1456: Proteomic Analysis Of Proteins Bound By D-4F In Plasma From C57bl/6 And ApoA-I KO Mice
Authors: Xu Hao , Pritchard Kirkwood A , Wakim Basam , Olivier Michael , Shi Yang
Published: July 2021

D-4F, an 18 amino acid apolipoprotein A-I (ApoA-I) mimetic, has been shown to be highly effective at improving vascular function in murine models of atherosclerosis. It has been hypothesized that D-4F inhibits atherosclerosis and increases vasodilation by interacting with ApoA-I to improve HDL function. However, the mechanisms by which D-4F protects vascular function remain unclear. We hypothesize that D-4F binds proteins involved in atherosclerosis. To test this hypothesis, we incubated HA-tagged D-4F with plasma from C57bl/6 and ApoA-I knockout mice (ApoA-I KO) on a C57bl/6 background and identified the proteins that were bound. Plasma from C57bl/6 mice or ApoA-I KO mice (n=6/group) was incubated with HA-GG-D-4F (Ac-YPYDVPDYA-GG-DWFKAFYDKVAEKFKEAF-NH2) or HA-GG-scramble-D-4F (Ac-YPYDVPDYA-GG-DWFAKDYFKKAFVEEFAK-NH2) at 10μg/ml. Next an anti-HA antibody was used to immunoprecipitate the HA-tagged peptides and associated proteins. The proteins were then analyzed by ESI-nano-LC/MS/MS. Analysis revealed that D-4F bound several proteins involved in lipid metabolism (ApoA-I, -II, -IV, ApoE, ApoC-I, -II and -III, -IV); complement regulatory protein (Complement C3); several kinases (PKC and Serine/threonine-protein kinase); and Serpins (Serine protease inhibitor 1 and A3K) which inhibit serine endopeptidases in C57bl/6 mice plasma. Although ApoA-I KO mice do not express ApoA-I, D-4F bound several lipoproteins associated with lipid metabolism (ApoE, ApoA-II, -IV, and ApoC-II, -III, -IV) in plasma from ApoA-I KO mice. D-4F also associated with the complement regulatory protein, Complement C3 in plasma of ApoA-I KO mice. Interestingly, D-4F bound serum paraoxonase and bradykinin only in the plasma of ApoA-I KO mice. These data show that D-4F associates, either directly or indirectly through lipoproteins, with a unique array of proteins involved in lipid metabolism; and second; that D-4F’s ability to associate with Complement C3, serum paraoxonase, bradykinin and Serpins suggest that D-4F may be able to modify the atherogenic properties of proteins involved in inflammation.
Abstract 1457: Cbl, E3 Ubiquitin Ligase, is a Regulator of Focal Adhesion Protein Proteasomal Degradation during Cardiomyocyte Anoikis
Authors: Rafiq Khadija , Seqqat Rachid , Hanscom Marie , Houser Steven R , Sabri Abdelkarim
Published: July 2021

Proteasome degradation of ubiquitin-targeted proteins is an important mechanism that negatively controls activated signaling pathways. The proto-oncogene Casitas b-lineage lymphoma (Cbl) is an adaptor protein with an intrinsic E3 ubiquitin ligase activity that targets receptor tyrosine kinase signaling, resulting in their ubiquitination and down-regulation. We have shown previously that neutrophil derived protease cathepsin G (Cat.G) induced focal adhesion (FA) protein degradation and myocyte apoptosis by anoikis. We hypothesized that Cbl is involved in myocyte apoptosis in response to Cat.G through ubiquitination and downregulation of FA proteins.

Results
: Immunoprecitpitation and western blot studies showed increased Cbl tyrosine phosphorylation in response to Cat.G that was associated with its interaction with FA proteins, FAK and paxillin. This led to an increase in FAK and Paxillin ubiquitination and degradation at 2 hrs after Cat.G addition. Inhibition of the ubiquitin proteasome system, with MG132 or lactacystin, or adenoviral expression of dominant negative mutant Cbl significantly reduced FAK and paxillin degradation. In contrast, adenoviral expression of wild type Cbl enhanced FAK and paxillin ubiquitination and degradation in response to Cat.G. Interestingly, Cbl activation was involved in Cat.G-induced myocyte apoptosis as overexpression of dominant negative Cbl significantly reduced caspase-3 activation and DNA fragmentation induced by Cat.G. Concomitant with these changes in vitro, heart tissue samples from patients with ischemic or dilated cardiomyopathy showed a marked increase in Cbl accumulation and FAK and paxillin degradation compared to heart controls.

Conclusion
: These studies show that Cbl abundance is increased in human ischemic and dilated cardiomyopathy and that activation of Cbl increases FA protein degradation and myocyte apoptosis. These results indicate that Cbl is a positive regulator of FA protein degradation and myocyte apoptosis and may play an important role in mediating the effect of neutrophil derived proteases during the progression of congestive heart failure.
Abstract 1459: Connexin 43 Hemi Channels are Permeable to Exogenously Added NAD: Implications in Protection of Cardiomyocytes against PARP-mediated Cell Death
Authors: Pillai Vinodkumar B , Pillai Jyothish B , Rajamohan Senthilkumar , Gupta Madhu , Raman Jai , Gupta Mahesh P
Published: July 2021

Robust activation of poly (ADP ribose) polymerase-1 (PARP) following oxidative stress and DNA damage is a major cause of caspase independent cardiomyocyte cell death. PARP-mediated cell-death is associated with cellular NAD depletion. Connexin 43 (Cx43) is a major gap junction protein which forms hemi channels in cardiomyocytes. This study was designed to investigate whether exogenously added NAD can enter into cardiomyocytes via Cx43 hemi channels, and protect cells from PARP-mediated cell death. Primary cultures of neonatal rat heart myocytes were treated at various time points with a free-radical generating mixture of H
2
O
2
and FeSO4 (0.1mM each). To examine permeability of cells to NAD, myocytes were treated with FITC-tagged-NAD (NAD-FITC) and intracellular localization of NAD was determined by confocal microscopy. We found that following oxidative stress myocyte cell death was proportionally related to intensity of PARP activation and NAD depletion. In these cells with PARP activation, exogenously added NAD-FITC (green) readily entered into the cell interior. This NAD transport was abolished when myocytes were treated with gap junction blockers such as carbenoxolone or 18β-glycyrrhetinic acid. To further confirm a role of Cx43 in NAD transport, we utilized HeLa cells in which Cx43 was either epigenetically silenced or constitutively over expressed. We found that HeLa cells lacking Cx43 had no NAD transport activity, while cells over expressing Cx43 showed abundant entry of NAD into the cells, thus validating a role of Cx43 in cellular NAD transport. Addition of NAD into culture media prior to PARP activation also rescued cells from PARP-mediated cell death. Cellular NAD levels are known to control the activity of the longevity factor SIRT1 deacetylase. To test if SIRT1 could be involved in mediating the beneficial effects of NAD, we did an identical cell death experiment with myocytes in which SIRT1 levels were reduced 50% by siRNA silencing. In these cells we found no beneficial effect of NAD following oxidative stress, thus indicating that SIRT1 is taking part in cell survival effects of NAD. These results demonstrate that exogenously added NAD can enter into cardiomyocytes via Cx43 hemi channels and protect cells against PARP-mediated cell death.
Abstract 1478: AMP-Activated Protein Kinase Phosphorylates Cardiac Troponin I and Alters Contractility in Murine Ventricular Myocytes
Authors: Oliveira S Marisa , Zhang Yin-Hua , Davies Joanne , Carling David , Casadei Barbara , Watkins Hugh , Redwood Charles
Published: July 2021

In the heart, AMP-activated protein kinase (AMPK) is critical in the regulation of energy balance and in myocardial signaling, and is activated especially during ischaemia and exercise. It is a αβγ heterotrimer, with α being the catalytic subunit. Mutations affecting the regulatory γ2 subunit have been shown to cause a cardiac phenotype of hypertrophy and conduction disease, thus suggesting a specific role for this subunit in the heart. The γ isoforms are highly conserved at their C-termini but very different at their N-termini; hence we have investigated whether the unique N-terminus of γ2 could be involved in conferring substrate specificity or in determining intracellular localization. We have undertaken a
GAL4
-based yeast two-hybrid assay to screen a human heart cDNA library using the N-terminal 273 residues of γ2 as bait. Five proteins were identified as true interactors in the yeast assay, one of these being cardiac troponin I (cTnI).
In vitro
studies showed that cTnI (isolated or reconstituted as troponin complex) is a good substrate for AMPK. Studies using site-specific cTnI mutants and mass spectrometry identified Ser-150 as the principal residue phosphorylated by AMPK. Actomyosin ATPase assays showed that phosphorylation at this residue resulted in increased Ca
2+
sensitivity of contractile regulation (ΔpCa
50
=+0.07). Treatment of cardiomyocytes with the AMPK activator AICAR for 15 min resulted in prolonged relaxation (time to 50% relaxation, TR50) in field stimulated left ventricular myocytes of C57B/6 mice (TR50 in ms: 29.8±1.4 in control and 38.0±2.4 with AICAR, n=11, 3 Hz and 35
o
C). There was a tendency towards an increase in contraction with AICAR. Pretreatment of myocytes with AMPK inhibitor compound C (10 μM) abolished the effects of AICAR on myocytes (TR50 in ms: 30.9±1.7 before AICAR and 31.5±2.6 after AICAR, n=9). The effect of AICAR was mediated without altering the amplitude of the Ca
2+
transient, suggesting that it may be caused by a change in myofilament Ca
2+
-sensitivity and consistent with AMPK phosphorylation of cTnI. We hypothesize that cTnI phosphorylation by AMPK may represent a novel mechanism of regulation of cardiac function.
Abstract 1485: Ischemic Postconditioning’s Protection Is Lost In Aged And Stat3-deficient Mice
Authors: Boengler Kerstin , Buechert Astrid , Heinen Yvonne , Hilfiker-Kleiner Denise , Heusch Gerd , Schulz Rainer
Published: July 2021

The cardioprotection by ischemic preconditioning is lost in aged wildtype (WT) mice and in STAT3-deficient mice (signal transducer and activator of transcription 3). The aim of the present study was to analyze

whether or not ischemic postconditioning (iPo) is effective in aged WT mice hearts, and

whether or not it is dependent on the presence of STAT3.

Young (3 months) and aged (>13 months) C57Bl6/J female mice underwent 30 min of ischemia and 2 h reperfusion (I/R) without or with iPo (3 cycles of 10 s ischemia and 10 s reperfusion (iPo3) or 5 cycles of 5 s ischemia and 5 s reperfusion (iPo5) at the beginning of reperfusion). In young mice hearts, iPo3 and iPo5 reduced the infarct size (IS, % of the area at risk) to a similar extent from 65.8±2.8 (n=11) to 50.7±2.8 (3×10, n=10, p<0.05) and to 49.8±3.8 (5×5, n=10, p<0.05). In contrast, in aged WT hearts IS was similar following I/R and iPo3 (60.1±3.2, n=10 vs. 66.4±3.0, n=7), but was reduced by iPo5 (46.5±4.2, n=7, p<0.05). Western blot analysis on right ventricular protein extracts from aged WT mice hearts indicated a reduction of phosphorylated STAT3 (Ser727) to 72.0±7.6% (n=19, p<0.05) and of total STAT3 to 72.1±5.5% (n=27, p<0.05) of that in young WT mice, which was set as 100% (n=18). In young mice (3 months) with a cardiomyocyte-restricted deletion of STAT3 (STAT3-KO) only iPo3 failed to reduce IS compared to I/R (62.2±3.5, n=5 vs. 64.4±3.1, n=8), whereas the stronger stimulus iPo5 once again significantly reduced IS (55.0±2.8, n=9, p<0.05). In conclusion, lower efficiency of iPO protection against I/R in aged mice hearts was associated with a reduced cardiac expression of STAT3. In line with a crucial role of STAT3 for iPO protection in I/R, STAT3-KO mice displayed also an attenuated susceptibility for iPO mediated protection in I/R. Thus age mediated reduction of cardiac STAT3 expression may contribute to the age-related reduced efficienty of iPo to protect from I/R injury.
Abstract 1492: Epigenetic Control of the eNOS Promoter by DNA Methylation in Vasculogenic Progenitor Cell Populations
Authors: Vlachojannis Georgios J , Urbich Carmen , Zeiher Andreas M , Dimmeler Stefanie
Published: July 2021

DNA methylation has been shown to play an essential role in both the transcriptional regulation and endothelial cell-specific expression of the human endothelial nitric oxide synthase (eNOS) gene. Further, recent data emphasizes an important role of eNOS in stem cell biology in particular with regard to progenitor cell mobilization and vasculoprotective properties. We assessed the hypothesis that stem and vasculogenic progenitor cells will exhibit different DNA methylation patterns of the eNOS promoter region dependent on their vascular fate. Endothelial progenitor cells (EPCs), mesangioblasts, CD34+, HUVECs and microvascular endothelial cells (MVECs) were cultivated and genomic DNA was subjected to sodium bisulfite treatment. The final PCR products were subcloned and sequenced (5–10 clones). Whereas the eNOS proximal promoter was either devoid or very lightly methylated in the human endothelial cell types including HUVECs and MVECs, the promoter was heavily methylated in the examined progenitor and stem cell types namely CD34+ and mesangioblasts. Surprisingly, EPCs also exhibit a profound methylation of the eNOS promoter (see Figure

). In conclusion, we have demonstrated that progenitor and stem cells including EPCs, CD34+ and mesangioblasts - although committed to a vascular fate - are in contrast to endothelial cell types heavily methylated in the promoter region of the eNOS gene suggesting epigenetic silencing at this level of maturation. The functional importance of this finding in particular regarding vasculoprotective potency and the modulation of methylation during progenitor cell maturation is subject of future studies.

Methylation pattern of the eNOS promoter
Abstract 1502: Gender-Specific Reversibility of Calcineurin-Induced Ventricular Remodeling
Authors: Le Vien , Tannous Paul , Berry Jeff M , Czubryt Michael P , Backs Johannes , Bassel-Duby Rhonda , Olson Eric N , Rothermel Beverly A , Hill Joseph A
Published: July 2021

Background:

Ventricular hypertrophy will sometimes reverse when the inciting stimulus (e.g. hypertension) is removed; at a certain point, however, pathological remodeling becomes irreversible. Further, recent studies have highlighted differences in disease pathogenesis triggered by signaling pathways activated in males (M) versus females (F). However, little is known regarding mechanisms of hypertrophy resolution, markers of irreversibility, or the effects of gender-specific mechanisms thereon.

Methods:

We engineered mice that express a constitutively active calcineurin mutant driven by a tet-off-αMHC promoter (tetCnA). During gestation, through weaning, and up to 5 wks of age, tetCnA mice were exposed to doxycycline (dox). Then, mice were randomized to dox (OFF) or dH2O (ON) for 16 wks. In the ON group, half received dH20 for 8 wks followed by dox for 8 wks (ON-OFF). Serial echocardiography was performed every 2 wks.

Results:

Systolic function declined significantly (p<0.05) and similarly by 8 wks in all ON mice (%FS = 37% ± 2, F-ON n=6; 35% ± 8, M-ON n=6; 38% ± 7, F-ON-OFF n=5; and 35% ± 2, M-ON-OFF n=5) as compared with OFF mice (%FS = 63% ± 5, F-OFF n=6; and 68% ± 7, M-OFF n=4). After 8 wks, resumption of dox to shut off calcineurin expression led to continued declines in systolic function in male mice (%FS at 16 wks 35% ± 3, M-ON-OFF n=5), similar to M-ON (30% ± 1, M-ON n=6), suggesting that pathological remodeling was irreversible. Conversely, systolic performance recovered completely in female ON-OFF mice (%FS at 16 wks = 62% ± 4, n=5) as compared with F-ON (36% ± 5, n=6, p<0.05). Necropsy at 16 wks revealed increased heart mass (p<0.05) in all ON mice and male ON-OFF mice (heart weight / tibia, HW/T = 12.4 ± 1.4 mg/mm, F-ON; 12.7 ± 2.1, M-ON; 12.0 ± 0.7, M-ON-OFF) as compared with all OFF mice (7.1 ± 0.4, F-OFF; 8.1 ± 0.5, M-OFF). Remarkably, heart mass at 16 wks was similar (p=NS) in F-ON-OFF (7.9 ± 0.4, n=5) and F-OFF mice, and accumulation of interstitial fibrosis was less as compared with all other groups.

Conclusions:

Calcineurin activation in adolescent male mice triggers pathological remodeling that is severe and irreversible after 2 months. In contrast, similar degrees of calcineurin-induced ventricular remodeling in adolescent female mice remain reversible at 2 months.
Abstract 1506: Upregulation of Cardiac AT
1
Receptor Signaling Inhibits Myocyte Contractile Performance, [Ca
2+
]
i
Transient, and Ca
2+
Current in Alcoholic Dogs: Insights into the Underlying Molecular Mechanism
Authors: Cheng Heng-Jie , Cunningham Carol C , Zhang Zhu Shan , Shihabi Zakariya K , Sane David C , Wannenburg Thomas , Masutani Satoshi , Little William C , Cheng Che-Ping
Published: July 2021

Background.
Chronic alcohol ingestion is accompanied by sustained renin-angiotensin system (RAS) activation followed by progressive left ventricular (LV) myocyte dysfunction. This suggests a role for angiotensin II (AII) in the development of alcoholic cardiomyopathy (ACM). We tested the hypothesis that chronic alcohol intake may cause upregulation of AII AT
1
receptors and altered cardiac inotropic response to AII stimulation, thus contributing to the development of ACM.

Methods.
We compared LV myocyte AT
1
- and AT
2
-receptor mRNA and protein levels, myocyte contractile function, [Ca
2+
]
i
transients ([Ca
2+
]
iT
), and Ca
2+
current (I
Ca,L
) in response to AII (10
−6
M) in 16 instrumented dogs over 6 months. Eight animals received alcohol (once per day orally, providing 33% of total daily caloric intake), and eight were controls. Myocytes were isolated from LV myocardial biopsy tissues.

Results
. Compared with controls, the alcoholic myocytes showed increased AT
1
mRNA (0.69 vs 0.33) and protein levels (0.79 vs 0.37) (
p
<0.01). Conversely, AT
2
mRNA (0.18 vs 0.16) and protein concentration (0.16 vs 0.14) were relatively unchanged. Importantly, in alcoholic myocytes, the increased AT
1
receptors were associated with altered myocyte inotropic response to AII. In control myocytes, superfusion of AII (10
−6
M) increased myocyte systolic amplitude (SA, 14.9 vs 12.4%) and the maximum rate of shortening (dL/dt
max
, 203.1 vs 153.9 μm/s) accompanied by significant increases in [Ca
2+
]
iT
(1.52 vs 1.21) and I
Ca,L
(4.0 vs 3.3 pA/pF). In alcoholic myocytes, this positive response was reversed. AII caused significant decreases in SA (3.4 vs 5.8 %), dL/dt
max
(50.5 vs 78.9 μm/s), and the maximum rate of relaxation (dR/dt
max,
37.5 vs 59.6 μm/s) associated with reduced [Ca
2+
]
iT
(0.86 vs 1.12) and I
Ca,L
(1.5 vs 2.1 pA/pF) (
p
<0.05). These AII-induced changes in alcoholic myocytes were abolished by incubation of alcoholic myocytes with an AT
1
receptor blocker, losartan (10
−5
M), or pretreatment with a G
i
inhibitor, PTX (2 μg/ml, 36°C, 5h).

Conclusions.
In a canine model, chronic alcohol consumption produces upregulation of LV myocyte AII AT
1
receptors and alters myocyte functional response to AII stimulation, which may promote the development of ACM.
Abstract 1517: Does Angiogram Make A Difference In The Outcome Of Acute Coronary Syndrome? A Study On Sex Difference In Outcomes In South America.
Authors: Bugiardini Raffaele , Rolandi Florencia , Bazzino Oscar , Manfrini Olivia , Pascua Andres , Botto Fernando , Fuselli Juan , Matas Carlos Rojas , Estrada Jose L Navarro
Published: July 2021

HYPOTHESIS. Women presenting with acute coronary syndrome are less likely to have significant coronary artery disease (CAD) than men, which could narrow wide differences in sex outcomes when evaluating the study population as a whole.

METHODS. The Prognosis in Acute Coronary Syndromes Registry enrolled 823 patients (591 men and 232 women) who had been hospitalized for an acute coronary syndrome without ST-segment elevation and had undergone cardiac catheterization. We explored sex-based differences in presentation and outcomes, sorted by angiographic groups: obstructive (≥50% stenosis, accordingly to quantitative computerized analysis) versus non-obstructive CAD. Patients were followed up for 6 months.

RESULTS. In obstructive CAD, women were older than men (71.4 ± 9.7 versus 64.4 ± 11.1 years, p<0.001), and had significantly higher rates of hypertension (51.9% versus 39.7%, p<0.001). Women were less likely to have smoked (19.3% versus 29.8%, p<0.01). A smaller percentage of women than men had non-ST elevation myocardial infarction as an index event (7.7% versus 22.8%, p<0.001) and positive troponin value (51.3% versus 67.4%, p<0.01). At follow-up women showed no differences in myocardial infarction, rehospitalization for unstable angina or revascularization, but they did suffer an increased rate of cardiovascular death (8.4% versus 3.4%, p<0.01), with a hazard ratio 2.34 (95%CI: 1.13– 4.84, p=0.023). Relation between sex and death remained significant even after adjustment for any confounders (hazard ratio 2.48; 95%CI: 1.19–5.15, p=0.015). In non-obstructive CAD group, the clinical characteristics and prognostic end-points (death: 0% men versus 1% women) did not significantly differ between men and women.

CONCLUSIONS. In conclusion, women with obstructive CAD suffer an increased rate of cardiovascular death after acute coronary syndrome. Inclusion of large numbers of women with non-obstructive coronary disease in calculations based on the entire cohort may mistakenly shift results toward apparent outcome similarity with men.
Abstract 1521: Platelet RNA Content is Increased in Patients with Acute Coronary Syndromes Compared to Patients with stable Coronary Artery Disease and Healthy Individuals
Authors: Grove Erik L , Hvas Anne-Mette , Kristensen Steen D
Published: July 2021

Background:
Platelets newly released from the bone marrow are characterized by large cell volumes and, contrary to mature platelets, contain RNA, which might reflect an increased capacity of producing proaggregatory proteins. We hypothesized that the fraction of RNA-containing, immature platelets (Immature Platelet Fraction = IPF) is a marker for acute coronary thrombus formation.

Methods:
Flow cytometric determination of immature platelets was conducted using a RNA fluorescent dye and an automated analyzer (Sysmex XE-2100). Measurements were performed in a total of 426 individuals (365 patients with acute coronary syndromes (ACS), 39 patients with stable coronary artery disease (CAD) and 22 healthy individuals).

Results:
Geometric mean IPF was 2.5 (CV = 0.37) in the control group, 2.9 (0.43) in patients with stable CAD, 3.0 (0.55) in the non-STEMI/Unstable Angina group and 3.7 (0.56) in patients with STEMI. IPF was significantly increased in STEMI patients compared to all other groups (t-test for log-transformed data: p < 0.004), and the overall difference between groups was significant (ANOVA: p < 0.0001). IPF was increased in active smokers among patients with ACS (3.2 vs 3.6, p=0.02), whereas no relation with age, sex, body mass index or CRP levels was observed.

Conclusion:
The fraction of RNA-containing platelets is increased in ACS, especially in the acute phase of STEMI. Immature platelets with an increased haemostatic potential may contribute to coronary thrombus formation and may partly explain previous findings of temporary resistance to anti-platelet therapy.
Abstract 1542: Value of High Output Pacing in Mapping of Post-Infarction Ventricular Tachycardia
Authors: Sarrazin Jean-Francois , Good Eric , Kuhne Michael , Wells Darryl , Chalfoun Nagib , Crawford Thomas , Wimmer Alan , Dey Sujoya , Boonyapisit Warangkna , Oral Hakan , Pelosi Fred , Jongnarangsin Krit , Chugh Aman , Morady Fred , Bogun Frank
Published: July 2021

Introduction:
Identification of critical isthmus sites for post-infarction ventricular tachycardia (VT) ablation can be challenging. Unexcitable scar during pacing can identify one of the borders of the re-entry circuit. This area however is not thought to be critical to the circuit. Because of current-to-load mismatch, higher power might be required in order to obtain capture of individual surviving muscle bundles within scar tissue. The purpose of this study was to evaluate the value of high output capture of scar tissue in patients with post-infarction VT.

Methods:
In a consecutive series of 18 patients (15 men, age 62 ± 9, EF 0.28 ± 0.15) with post-infarction VT, mapping was performed using an electroanatomic mapping system. A voltage map was obtained during sinus rhythm and bipolar pace-mapping was performed in areas with low voltage (< 1.5 mV) with an output of 10 mA at a pulse width (PW) of 2 ms. High output capture was defined when capture at these settings failed but capture could be achieved with increased output. If there was no capture at the initial settings, output was increased to 20 mA at a PW of 2 ms, eventually the PW was increased up to 10 ms as required to achieve capture. A critical isthmus was defined as a site with a matching pace-map, and/or matching stimulus-QRS to electrogram-QRS intervals in the presence of concealed entrainment, and/or mechanical termination of VT and failure to induce VT after radiofrequency ablation.

Results:
Focal areas with high output capture could be observed in 10/18 (56%) patients. In 9/10 patients in whom high output capture was present (mean output: 20 mA; mean pulse width: 7.4 ms), this area was critical for the re-entry circuit of 10 VTs (cycle length 444 ± 72 ms). A total of 77 VTs (cycle length 390 ± 115 ms) was induced in these patients. Forty-three isthmus sites could be identified and effectively ablated for 56 of the VTs. During a follow-up of 4.9 ± 5.3 months 2 patients had VTs that were not targeted during the ablation.

Conclusions:
High output pacing is helpful in identifying critical areas of post-infarction VT that otherwise might be missed.
Abstract 1553: Comparative Gene Expression Analysis of Blood and Heart Identifies Genomic Predictors of Myocardial Injury Following Cardiopulmonary Bypass and Cardioplegic Arrest in the Rat
Authors: Podgoreanu Mihai V , Yoshitani Kenji , Dobra Adrian , Ma Qing , Zhu Bin , Mackensen G B
Published: July 2021

Background: Perioperative myocardial injury (PMI) complicating cardiac surgery remains poorly predicted by clinical risk factors. In a novel rat model of cardiopulmonary bypass (CPB) and cardioplegic arrest (CA) we tested the hypothesis that microarray expression profiles in peripheral blood leukocytes (PBL) can accurately predict degree of PMI, and compared genomic signatures in left ventricular myocardium (LVM) and PBL to identify PMI-associated genes that generalize across tissues.

Methods: Male rats subjected to CPB only (75 min), CPB with CA (30 min), and sham surgery (n=5 each) had plasma heart fatty acid binding protein (HFABP) and cardiac troponin I (cTnI) measured 1 hour post CPB and microarray profiling of total RNA from LVM and PBL. PMI genomic classification models were constructed using shotgun stochastic search approach and Bayesian model averaging and their accuracy tested by five-fold cross validation.

Results: A spectrum of PMI was observed in the experimental groups as well as robust deregulation of gene expression in a stimulus and tissue-specific manner (Figure

). Estimates of PMI classification accuracy from PBL and LVM are presented in Table

.

Conclusions: Cardiac surgery induces changes in leukocyte gene expression that predict the spectrum of PMI, with potential applications in perioperative risk stratification and selection of cardioprotective strategies.

Predictive accuracy of tissue-specific myocardial injury genomic classifiers
Abstract 1561: Is Aprotinin Really Safe In Thoracic Aortic Surgery? Analysis Of Outcome
Authors: Banfi Carlo , De Lentdecker Philippe , Schlumberger Sylvie , Klersy Catherine , Bachet Jean , Dubois Claude , Goudot Bertrand , Missaoui Chakir , Hermi Nabil , Guilmet Daniel , Dreyfus Gilles , Fischler Marc , Debauchez Matthieu
Published: July 2021

Introduction
: We aimed at evaluating aprotinin efficacy and renal, cardiac and neurologic safety after thoracic aortic surgery in a single Center.

Methods
: This retrospective longitudinal study analyses 742 patients (26% female), aged 57 years (SD 15), operated between January 1993 and December 2006. Efficacy and safety were the primary endpoints. Efficacy was defined as perioperative bleeding ≤1200 ml/first 24 h and/or no reintervention for bleeding. Renal adverse events included increased values of creatinine and BUN and/or the initiation of dialysis. Cardiac adverse events included perioperative myocardial infarction, acute LOS, and progression to heart failure. Neurologic adverse events included stroke, transient ischemia and/or clinical neurologic deficits.

Results
: Aprotinin was given to 525 pts. only. Table 1

shows the outcome according to aprotinin administration. Patients receiving aprotinin had higher bleeding, and renal, neurologic adverse events rate (univariate analysis). Cardiac adverse events and perioperative mortality are similar in both groups. However no evidence of effect was left when accounting for possible confounders (urgent surgery, redo procedure, dissection, antiplatelet medication, NYHA class, deep hypothermia, CPB time).

Conclusions
: The influence of aprotinin shown at univariable analyis, disappeared when controlling for a series of potential confounders in a multivariable analysis. A randomized control clinical trial would have better answered the question as whether aprotinin has a beneficial therapeutic effect together with a high safety. However, this sample size allowed controlling the effect of the drug for a large series of potential confounders in a multivariate analysis. Thus we were able to elicit a lack of association of aprotinin (ORs close to 1 and narrow 95% CIs) with both efficacy and adverse events.

Table 1
Abstract 1563: Angiotensin II Type 2 Receptor Expression and CD34 Progenitor Cell Co-localization in Aortic Aneurysm
Authors: Nataatmadja Maria , West Jennifer , West Malcolm
Published: July 2021

Altered expression of angiotensin II type-1 and type-2 receptors (AT1, AT2) has been implicated in the development of aortic aneurysm. We used immunohistochemistry to examine the expression of AT1 and AT2 in thoracic and abdominal aortic aneurysm. Thoracic and abdominal aortic tissue samples were collected from organ donor subjects (normal controls; 4M, 9F; age 40±12yr, mean ± SD), and subjects with Marfan syndrome (MFS; 6M, 3F; 42±24yr), bicuspid aortic valve (BAV; 10M, 4F; 62±17yr) or abdominal aortic aneurysm (AAA; 8M, 2F; 72±10). In each type of aneurysm there was mild expression of AT1 and moderate expression of AT2 associated with intimal thickening and the tunica adventitia compared to mild expression of AT1 and negligible expression of AT2 in control aorta. In aneurysm tissue AT1 and AT2 expression, transforming growth factor (TGF)-beta1 expression and progenitor cell (CD34+) localization were also present in areas of tissue remodeling associated with focal medial degeneration, angiogenesis and areas of inflammation. In cell culture experiments aortic fibroblasts (AF) derived from adventitial aneurysm tissue showed moderate expression of AT1 and strong expression of AT2 while control AF showed mild expression of AT1 and negligible expression of AT2. Negligible to mild expression of active TGF-beta1 was observed in all cultured AF. Interestingly adventitial aneurysm cultured in endothelial growth media resulted in the appearance of spindle shaped cells with CD31+ endothelial colonies sprouting among them. Moderate active TGF-beta1 and AT1 and strong AT2 expression were observed in these CD31+ cells. Cultured control adventitia only had spindle cell outgrowth and negligible active TGF-beta1, AT1 and AT2 expression. In summary aneurysm tissue and cultured AF and CD31+ cells of aneurysm origin showed increased expression of AT2 and an absence of increased AT1 expression. Increased AT2 expression in areas of pathological remodeling suggests an active role for AT2 in aneurysm development. Co-localization of increased AT2 with active TGF-beta1 expression and CD34+ cells suggests a role for AT2 in endothelial differentiation and angiogenesis.
Abstract 1566: Tumor Necrosis Factor Receptor 2 Signaling Protects Myocardial Function Following Ischemia In Females Via Stat3, Socs3 And Vegf
Authors: Wang Meijing , Crisostomo Paul , Markel Troy , Meldrum Daniel R
Published: July 2021

Introduction: Myocardial ischemia/reperfusion (I/R) increases local TNF production, which contributes to myocardial dysfunction; however, the mechanisms remain incompletely understood. Some investigations have shown that TNF may be protective and others have shown it to be injurious. Our previous studies have shown that females have improved myocardial functional recovery, TNFR1 signaling resistance, and increased SOCS3 expression following acute I/R when compared to males. However, the effect of TNFR2 on gender differences in myocardial functional recovery following I/R is unknown. We hypothesized that

TNFR2 mediates myocardial protection from I/R through STAT3, SOCS3 and VEGF in both genders,

TNFR2 elicits greater protective signaling in females as compared to males.

Methods: Isolated male and female mouse hearts (Langendorff) from TNFR2 knockout (TNFR2 KO), TNFR1/2KO and wild type (WT) (n=3– 6/group) were subjected to 20 minutes of ischemia followed by 60 minutes of reperfusion. Myocardial function (+/−dP/dt) was continuously monitored. After I/R, hearts were analyzed for STAT3, SOCS3 and VEGFa gene expression (RT real-time PCR), STAT3 activation (Western blot). Two-way ANOVA or student’s t-test, p<0.05 statistically significant.

Results: TNFR2 deficiency decreased post-ischemic recovery of +/−dP/dt in both genders, but with greater effect on females. This deleterious effect of TNFR2KO was associated with a decrease in gene expression of VEGFa to 38%, STAT3 to 51% and SOCS3 to 36% in female TNFR2KO hearts, but without significant change in males. Additionally, TNFR1/2 KO decreased myocardial function in female hearts, but not in males. Interestingly, TNFR1/2 deficiency increased gene expression of VEGFa by 37%, SOCS3 by 30% in males, but decreased VEGFa by 48%, STAT3 by 45% and SOCS3 by 49% in females. Moreover, STAT3 activation was decreased in female TNFR2KO and TNFR1/2KO hearts.

Conclusions: TNFR2 mediates myocardial protection through VEGF, STAT3 and SOCS3 following I/R in both genders, but with a relatively greater benefit of TNFR2 signaling observed in females. These data expand upon gender-based TNF signaling in myocardium, which may in part explain certain clinical differences with important therapeutic implications.
Abstract 1585: Echocardiographic Left Ventricular Volumes are Optimally Indexed to Fat Free Mass to Adjust for Differences in Body Size
Authors: Doughty Robert N , Walsh Helen J , Gamble Greg D , Cross Philippa A , Aoina James , Gill Aiden , Somaratne Jithendra B , Whalley Gillian A
Published: July 2021

Introduction
Echocardiographic left ventricular (LV) size and structure are commonly indexed to body surface area (BSA) to adjust for body size. However, BSA may not be the optimal variable to adjust measurements to. While previous studies have demonstrated that the best determinant of LV mass is fat free mass (FFM), the relationship of LV volumes with body composition is uncertain.

Objectives
To determine the relationships between LV size and body composition.

Methods
Normal subjects (Caucasian, Maori, Samoan, Chinese and Indian ethnicity) free of cardiac disease underwent medical history, ECG, blood test (cholesterol/glucose), echocardiography for LV volumes (2D biplane methods of discs) and DEXA scans (body composition).

Results
166 subjects were assessed: 96 (56%) were women, median age 26yrs, mean BMI 25.4 (SD 6.0), BSA 1.85m
2
(SD 0.28), LVEDV 88ml (SD 27), LVESV 33ml (SD 14). Significant correlations were observed between LV size and measures of body size in all ethnic groups. However, FFM was the best independent predictor of LV volumes (LVEDV partial R
2
0.48 – 0.60). Body size was smallest among Asian subjects and highest among Maori & Samoan subjects. A significant difference in unindexed LVEDV was observed across the groups which persisted when indexed to BSA or height (all P<0.01). However, when LVEDV was indexed to FFM the ethnic differences were reduced (figure

).

Conclusions
Among normal subjects LV size is strongly related to FFM. Indexing LV volumes to FFM largely eliminated the differences in LVEDV between subjects with varying body composition. Reference and partition values for normal LV size should be based on LV volumes indexed to fat free mass.
Abstract 1597: Safety and Efficacy of Inhaled Iloprost Via a Disposable Nebulizer in Heart Failure Patients With Elevated Pulmonary Vascular Resistance
Authors: Baran David , Arroyo Luis H , Hebron Jill , Carr Candace , Zucker Mark J
Published: July 2021

Background

: Pulmonary vascular resistance (PVR) is routinely measured in patients (pts) being evaluated for a heart transplant. Pts with a high PVR are often treated with a milrinone or intravenous vasodilator “challenge” to establish that the PVR is not “fixed”. However, all current agents have dose-limiting side effects such as arrhythmias and hypotension. Inhaled iloprost would be an option but it is given with a costly adaptive aerosol delivery device. In addition, the efficacy and safety of this drug in left heart failure is poorly studied.

Methods

: 10 adult heart failure pts who were found to have a PVR of greater than 200 dyne-sec on routine right heart catheterization were enrolled. 50 micrograms (mcg) of iloprost was inhaled while in the catheterization laboratory using a disposable nebulizer and outflow filter, over 10 minutes. Hemodynamics were monitored at baseline, following drug inhalation, and 20 minutes later.

Results

: The average age of the patients (6 male, 4 female) was 64.8 ± 8.9 years. The mean left ventricular ejection fraction was 20.6 ± 8.6 %. The mean creatinine clearance (Cockroft-Gault) was 48.7 ± 18.9 ml/hr. The mean arterial pressure (MAP), pulmonary artery systolic (PAS), PA diastolic (PAD), PCWP, transpulmonic gradient (TPG), cardiac output (CO), and PVR at baseline, 10 minutes and 20 minutes post-inhalation are detailed below. Iloprost significantly reduced PAS, TPG and PVR without changes in MAP, PAD, PCWP or CO. These effects remained significant at study completion as well. There were no adverse events noted.

Conclusion

: Iloprost inhalation was well tolerated in heart failure patients undergoing right heart catheterization. Inhalation of 50 mcg of iloprost via a simple hospital nebulizer was associated with safe, rapid, and significant declines in indices of pulmonary vascular tone, without affecting cardiac output or PCWP. Further investigation of this novel use of iloprost is warranted.

Results
Abstract 1603: Factors and Mechanisms Associated with Improved Cardiopulmonary Performance after Cardiac Resynchronization Therapy. An Exercise Echocardiography Study.
Authors: Madaric Juraj , Vanderheyden Marc , Van Lathem Christophe , Feys Ann , Verstreken Sofie , Goethals Marc , De Bruyne Bernard , Bartunek Jozef
Published: July 2021

Background:
Cardiac resynchronization therapy (CRT) leads to better cardiopulmonary performance in congestive heart failure (CHF) patients (pts). Mechanisms underlying the benefits are not fully elucidated.

Aim:
To investigate factors and mechanisms associated with improved cardiopulmonary performance after CRT.

Methods:
Twenty-three pts (EF 26±7%, QRS complex 170±26 msec) were studied by simultaneous quantitative semi-supine exercise echocardiography and cardiopulmonary exercise testing before and 3 months after CRT. Pts with an increase (Δ) in peak VO
2
≥1.1 ml/kg/min were considered clinical responderes. Effective regurgitant orifice (ERO) of the mitral regurgitation (MR) was assessed using the PISA method.

Results:
In the entire population, CRT was associated with a decrease in LV dyssynchrony from 53±2 to 23±9 msec (p<0.001), increase LV ejection fraction (EF) from 26±7 to 36±9% (p<0.001) and ERO reduction from 0.24±0.11 to 0.13±0.06 cm
2
(p<0.001) In addition, peak VO
2
increased from 11.6±2.3 to 12.9±3.6 ml/kg/min (p<0.01) and Nt-pro BNP decreased from 2795±1644 to 2021±1353 pg/ml (p<0.05). At follow-up (Table

), ERO at rest was similar but exercise-induced ERO and Nt-pro BNP were significantly lower in responders vs nonresponders. Change in peak VO
2
correlated inversely with the extent of exercise-induced MR at follow-up (r=−0.47, p<0.05), with baseline Nt-pro BNP levels (r=−0.53, p<0.05) and change in LVESV (r=−0.49, p<0.05).

Conclusions.
Improved cardiopulmonary performance after CRT is related to changes in exercise-induced MR rather than resting MR. Thus, effects on the exercise-induced MR in parallel to reverse LV remodelling appear to contribute to improved cardiopulmonary performance and clinical benefits of the CRT.
Abstract 1604: Response to Cardiac Resynchronization Therapy Differs Between Patients With and Without Previous Right Ventricular Pacing
Authors: Thelen Andrea M , Kaufman Christopher L , Burns Kevin V , Kaiser Daniel R , Kelly Aaron S , Bank Alan J
Published: July 2021

Background:
Previous large studies on the effects of cardiac resynchronization therapy (CRT) in patients with heart failure have generally excluded patients previously paced from the right ventricle (RV). Previously RV paced patients (RVp) can exhibit an iatrogenic cause of dyssynchrony and reduced systolic function and thus, may respond differently to CRT than patients not previously RV paced (nRVp). The purpose of this study was to test the hypothesis that RVp patients have greater improvements in left ventricular systolic function, volumes, and dyssynchrony in response to CRT than nRVp.

Methods:
Standard echocardiograms with tissue Doppler imaging were performed before and after chronic CRT in RVp (n = 21, 16 male) and nRVp (n = 70, 54 male) heart failure patients. Ejection fraction (EF), left ventricular end diastolic (LVEDV) and systolic (LVESV) volumes were calculated using the biplane Simpson’s method. Longitudinal dyssynchrony was calculated as the standard deviation of time to peak displacement (TT-12) of 12 segments in the apical views. Using mid-ventricular short axis views and speckle-tracking methods, radial dyssynchrony (Rad
dys
) was calculated as the maximal time difference between six myocardial segments for peak radial strain. Echo response was defined as ≥ 15% reduction in LVESV. Results are reported as mean ± SD.

Results:
Significant baseline differences (p < 0.05) were observed between groups (RVp vs. nRVp) for age (74 ± 13 vs. 67 ± 13 year), follow-up time (6.1 ± 1.8 vs. 4.6 ± 2.1 months), LVEDV (154.3±50.8 vs.185.3±56.9 mL), and a trend for LVESV (112.4 ± 40.6 vs. 134.9 ± 47 mL, p = 0 .05). No differences were observed for EF, etiology of heart failure, and dyssynchrony measures between groups at baseline. Echo response rate was significantly (
p
< 0.05) greater in RVp (76%) than nRVp (57%). After adjusting for baseline differences, RVp had greater improvement in EF (14 ± 9 vs. 8 ± 7%, p < 0.05) and LVESV (−33 ± 18 vs. −20 ± 21%, p < 0.05). After adjustment for follow-up time, no difference was observed for change in dyssynchrony between groups.

Conclusion:
RVp patients upgraded to CRT exhibit greater improvements in systolic function and ventricular remodeling as compared to nRVp patients.