bluuebunny/crossref_metadata_2025 huggingface dataset:
Circulating Oxidized LDL is a Useful Marker for Cardiovascular Risk Assessment
Authors: Mertens Ann , Verhamme Peter P , Verhaeghe Raymond , Muls Erik , Collen Desire , Van de Werf Frans , Holvoet Paul
Published: July 2021

0032

BACKGROUND: Coronary artery disease is associated with an increase in circulating oxidized (Ox)LDL (Circulation 1998; 98:1487-1494). OBJECTIVES: 1) To determine the usefulness of OxLDL for identifying cardiovascular disease patients and 2) to study the relation of OxLDL with cardiovascular risk factors. METHODS: 1) To determine the diagnostic value of OxLDL 308 subjects were studied: 178 patients with angiographically proven coronary artery disease and 130 age-matched subjects without cardiovascular disease (controls) confirmed by B mode ultrasonography of their carotid arteries. 2) Additional 307 patients without cardiovascular disease were studied to determine the relation of OxLDL with cardiovascular risk factors. Levels of OxLDL were directly measured in plasma using a mAb-4E6 based competition ELISA. RESULTS: Compared with controls, patients had 2.3-fold higher levels of circulating OxLDL. At a cutoff value of 2.30 mg/dL, the sensitivity of OxLDL for cardiovascular disease was 73% with a specificity of 90%. The Global Risk Assessment Score (GRAS) was calculated using age, total and HDL cholesterol, systolic blood pressure, diabetes mellitus and smoking. GRAS was 8.65±3.41 for patients versus 6.09±5.10 (p≤0.001) for controls. Compared with subjects with low OxLDL (≤2.30 mg/dL) and low GRAS (≤12), risk of having cardiovascular disease was 3.2 times higher for subjects with low OxLDL and high GRAS, 6.4 times higher for subjects with high OxLDL and low GRAS and 27 times higher for subjects with both high OxLDL and high GRAS. Among patients without cardiovascular disease, stepwise multivariate analysis showed that Body Mass Index (p<0.001), LDL cholesterol (p<0.001), diabetes type 2 (p=0.003), triglycerides (p=0.017) and smoking (p=0.046) were the strongest predictors of OxLDL. Conclusion: Circulating OxLDL is a sensitive marker of cardiovascular disease. Circulating oxidized LDL correlates with obesity, hypercholesterolemia, diabetes and smoking. Addition of OxLDL to the established risk factors may improve cardiovascular risk prediction. Inclusion of OxLDL in prospective studies of risk factors of cardiovascular disease seems to be warranted.
Very Long-Term Survival and Durability of Mitral Valve Repair for Mitral Valve Prolapse
Authors: Mohty Dania , Orszulak Thomas A. , Schaff Hartzell V. , Avierinos Jean-Francois , Tajik Jamil A. , Enriquez-Sarano Maurice
Published: July 2021

Background

Mitral regurgitation (MR) due to mitral valve prolapse (MVP) is often treatable by surgical repair. However, the very long-term (>10-year) durability of repair in both anterior leaflet prolapse (AL-MVP) and posterior leaflet prolapse (PL-MVP) is unknown.

Methods and Results

In 917 patients (aged 65±13 years, 68% male), surgical correction of severe isolated MR due to MVP (679 repairs and 238 replacements [MVRs]) was performed between 1980 and 1995. Survival after repair was better than survival after MVR for both PL-MVP (at 15 years, 41±5% versus 31±6%, respectively;
P
=0.0003) and AL-MVP (at 14 years, 42±8% versus 31±5%, respectively;
P
=0.003). In multivariate analysis adjusting for predictors of survival, repair was independently associated with lower mortality in PL-MVP (adjusted risk ratio [RR] 0.61, 95% CI 0.44 to 0.85;
P
=0.0034) and in AL-MVP (adjusted RR 0.67, 95% CI 0.47 to 0.96;
P
=0.028). The reoperation rate was not different after repair or MVR overall (at 19 years, 20±5% for repair versus 23±5% for MVR;
P
=0.4) or separately in PL-MVP (
P
=0.3) or AL-MVP (
P
=0.3). However, the reoperation rate was higher after repair of AL-MVP than after repair of PL-MVP (at 15 years, 28±7% versus 11±3%, respectively;
P
=0.0006). From the 1980s to the 1990s, the RR of reoperation after repair of AL-MVP versus PL-MVP did not change (RR 2.5 versus 2.7, respectively;
P
=0.58), but the absolute rate of reoperation decreased similarly in PL-MVP and AL-MVP (at 10 years, from 10±3% to 5±2% and from 24±6% to 10±2%, respectively;
P
=0.04).

Conclusions

In severe MR due to MVP, mitral valve repair compared with MVR provides improved very long-term survival after surgery for both AL-MVP and PL-MVP. Reoperation is similarly required after repair or replacement but is more frequent after repair of AL-MVP. Recent improvement in long-term durability of repair suggests that it should be the preferred mode of surgical correction of MVP whether it affects anterior or posterior leaflets and is an additional incentive for early surgery of severe MR due to MVP.
Posterior Pericardial Ascending-to-Descending Aortic Bypass
Authors: Connolly Heidi M. , Schaff Hartzell V. , Izhar Uzi , Dearani Joseph A. , Warnes Carole A. , Orszulak Thomas A.
Published: July 2021

Background

Coarctation of the aorta is commonly associated with recoarctation or additional cardiovascular disorders that require intervention. The best surgical approach in such patients is uncertain. Ascending-to-descending aortic bypass graft via the posterior pericardium (CoA bypass) allows simultaneous intracardiac repair or an alternative approach for the patient with complex coarctation.

Methods and Results

Between 1985 and 2000, 18 patients (13 males and 5 females, mean age 43±13 years) with coarctation of the aorta underwent CoA bypass through median sternotomy. Before operation, average New York Heart Association class was II (range I to IV), and 15 patients (83%) had systemic hypertension. One or more previous cardiovascular operations had been performed in 12 patients (67%); 10 patients had ≥1 prior coarctation repair. Two patients had prior noncoarctation cardiovascular surgery. Concomitant procedures performed in 14 patients (78%) included the following: aortic valve replacement in 9; coronary artery bypass surgery in 3; mitral valve repair in 2; and septal myectomy, mitral valve replacement, aortoplasty, subaortic stenosis resection, ventricular septal defect closure, and ascending aorta replacement in 1 patient each. All patients survived the operation and were alive with patent CoA bypass at a mean follow-up of 45 months. No graft-related complications occurred, and there were no instances of stroke or paraplegia. Systolic blood pressure fell from 159 mm Hg before surgery to 125 mm Hg after surgery.

Conclusions

CoA bypass via median sternotomy can be performed with low morbidity and mortality. Although management must be individualized, extra-anatomic CoA bypass via the posterior pericardium is an excellent single-stage approach for patients with complex coarctation or recoarctation and concomitant cardiovascular disorders.
Normalized Diastolic Properties After Left Ventricular Assist Result From Reverse Remodeling of Chamber Geometry
Authors: Barbone Alessandro , Oz Mehmet C. , Burkhoff Daniel , Holmes Jeffrey W.
Published: July 2021

Background

Normalization of diastolic properties after left ventricular (LV) assist may result from a change in myocardial material properties, chamber size, or both. This study tested the hypothesis that reported normalization of LV diastolic properties is primarily due to remodeling of chamber geometry.

Methods and Results

Hearts were obtained at transplantation from 8 patients with dilated cardiomyopathy (DCM), 6 patients with DCM plus 33±5 days of LV assist, and 3 patients with no evidence of heart failure. LV assist normalized passive pressure-volume curves. Chamber dimensions decreased without a change in the ratio of radius to wall thickness. Midwall stress-stretch relations predicted from pressure-volume and dimension data were not different for DCM and LV assist hearts. Passive stress-stretch relations were measured in endocardial trabeculae and were not different for DCM and LV assist hearts. Myocyte size and collagen area fraction were unchanged at this brief duration of support.

Conclusions

These findings are all consistent with the hypothesis that early normalization of diastolic properties after LV assist device support results from remodeling of chamber geometry, not from changes in tissue stiffness. These data emphasize the importance of geometry to ventricular mechanics and demonstrate that reduction of heart size does not necessarily produce a reduction in wall stress.
Initial Effects of the Left Ventricular Repair by Plication May Not Last Long in a Rat Ischemic Cardiomyopathy Model
Authors: Nishina Takeshi , Nishimura Kazunobu , Yuasa Sadatoshi , Miwa Senri , Nomoto Takuya , Sakakibara Yutaka , Handa Nobuhiro , Hamanaka Ichiro , Saito Yoshihiko , Komeda Masashi
Published: July 2021

Background

Long term effects of left ventricle (LV) repair surgery (LVR) for ischemic cardiomyopathy are not well understood.

Methods and Results

Sixty-nine rats developed ischemic cardiomyopathy with large akinetic LV area 4 weeks after the left anterior descending artery was ligated. In a second surgery 4 weeks later, 33 rats underwent LVR by plication of the akinetic LV area (LVR group), and 36 underwent rethoracotomy alone (sham group). No medication was used in either group. All rats survived the second surgery. LV end-diastolic dimension as measured by echocardiography, LV fractional shortening, and the maximal end-systolic pressure-volume relationship (E
max
) as calculated from the data by catheter-tipped manometer and echocardiography improved in the LVR group after the second surgery, but LV end-diastolic dimension and E
max
gradually deteriorated as time passed. LV end-diastolic pressure improved 1 week after LVR but rose significantly 4 weeks after LVR. Brain natriuretic peptide mRNA was lower in the LVR group than in the sham group 1 week after LVR but not 4 weeks postoperatively.

Conclusions

Initial improvement in LV function and neurohormonal status after LVR did not last for 4 weeks in this rat model when untreated medically. The mechanism of deterioration should be elucidated to improve long-term results of LVR.
Edge-to-Edge Mitral Repair
Authors: Nielsen Sten Lyager , Timek Tomasz A. , Lai David T. , Daughters George T. , Liang David , Hasenkam J. Michael , Ingels Neil B. , Miller D. Craig
Published: July 2021

Background

Edge-to-edge approximation of the mitral valve leaflets (Alfieri procedure) is a novel surgical treatment for patients with ischemic mitral regurgitation (IMR). Long-term durability may be limited if abnormal mitral leaflet stresses result from this procedure. The aim of the current study was to measure Alfieri stitch tension (F
A
) and to explore its geometric determinants in an ovine model of acute IMR as a reflection of the mitral leaflet stresses imposed by the procedure.

Methods and Results

Eight sheep were studied immediately after surgical placement of (1) a force transducer interposed between sutures approximating the central leaflet edges and (2) radiopaque markers around the mitral annulus and leaflet edges. Computer-aided analysis of videofluorograms was used to obtained 3D marker coordinates. Simultaneous measurements of F
A
, septal-lateral annular dimension (L
S-L
), leaflet edge separation (L
SEP
), anterior (L
AL
) and posterior (L
PL
) leaflet length, and hemodynamic variables were obtained at baseline (CTL) and during acute IMR (circumflex artery occlusion). F
A
was significantly elevated throughout the cardiac cycle during IMR compared with CTL, with maximum F
A
in diastole (0.26±0.05 versus 0.46±0.08 N, CTL versus IMR;
P
<0.05). Multivariable analysis revealed L
S-L
as the single independent predictor of maximum F
A
(
P
<0.001). Positive linear correlations were shown between values of F
A
and L
AL
and L
PL
(dependent variables).

Conclusions

These experimental data demonstrate higher F
A
during IMR and cyclic changes in F
A
closely paralleling changes in L
S-L
, eg, being greatest in diastole when the annulus is largest. Increased F
A
during IMR is probably indicative of successful therapeutic intent, but higher diastolic leaflet stresses resulting from persistent or progressive mitral annular dilatation may adversely affect repair durability. This indirectly implies that concomitant mitral ring annuloplasty should be added to the Alfieri repair.
Expression of Endomyocardial Nitric Oxide Synthase and Coronary Endothelial Function in Human Cardiac Allografts
Authors: Wildhirt Stephen M. , Weis Michael , Schulze Costas , Conrad Nicole , Pehlivanli Sinan , Rieder Gabi , Enders Georg , von Scheidt Wolfgang , Reichart Bruno
Published: July 2021

Background

Inducible nitric oxide synthase (iNOS) is expressed and is functionally active in the presence of transplant arteriosclerosis. However, the early involvement of iNOS in alterations of microvascular endothelial function in the absence of preexisting lesions remains unclear; this information would be of prognostic value. We studied the course of iNOS mRNA expression, transcardiac nitric oxide production, and their potential association with microvascular coronary endothelial dysfunction in human cardiac allografts.

Methods and Results

A total of 42 patients were studied at 1, 6, and 12 months after heart transplantation. Microvascular coronary flow velocity reserve (CFVR) was tested in an endothelium-dependent (acetylcholine) and -independent manner (adenosine) using a Doppler flow wire. Endomyocardial iNOS expression was determined by reverse transcription polymerase chain reaction. iNOS protein and nitrotyrosine levels were detected by immunohistochemistry. Transcardiac plasma nitrite/nitrate (NOx) levels were measured by the Griess reaction. CFVR was impaired in 26.1% of patients (n=11) at 1 month and in 31% of patients (n=13) at 12 months after heart transplantation. Patients who developed impaired CFVR in the first year showed a significant increase in iNOS gene expression. Patients with impairment of CFVR 1 month after heart transplantation had higher levels of iNOS mRNA than patients with a normal CFVR. Patients with an initial impairment of CFVR who did not improve over time presented with significantly higher iNOS mRNA levels. iNOS protein and nitrotyrosine were expressed in the endomyocardial vessels of patients with impaired CFVR. Transcardiac NOx release was higher in patients with impaired CFVR.

Conclusions

In human cardiac allografts, microvascular endothelial dysfunction is associated with an enhanced endomyocardial iNOS mRNA expression and higher transcardiac NOx production and is accompanied by the expression of nitrotyrosine protein, suggesting peroxynitrite plays a role in the disease process. The data from the present study suggest an important role for the iNOS/nitric oxide pathway in the regulation of microvascular function in the absence of preexisting atherosclerotic lesions.
Inhibition of Tumor Necrosis Factor-α Improves Postischemic Recovery of Hypertrophied Hearts
Authors: Stamm Christof , Friehs Ingeborg , Cowan Douglas B. , Moran Adrian M. , Cao-Danh Hung , Duebener Lennart F. , del Nido Pedro J. , McGowan Francis X.
Published: July 2021

Background

Tumor necrosis factor (TNF)-α has been implicated in the pathogenesis of heart failure and ischemia-reperfusion injury. Effects of TNF-α are initiated by membrane receptors coupled to sphingomyelinase signaling and include altered metabolism and calcium cycling, contractile dysfunction, and cell death. We postulate that pressure-overload hypertrophy results in increased myocardial TNF-α expression and that it contributes to decreased contractility in hypertrophied infant hearts subjected to ischemia-reperfusion.

Methods and Results

Neonatal rabbits underwent aortic banding to induce LV hypertrophy. Myocardial TNF-α protein expression increased progressively with LV hypertrophy. Serum TNF-α was detected only after the onset of heart failure. Before onset of ventricular dilatation and heart failure (determined by serial echocardiograms), hearts from aortic banded and age-matched control rabbits were perfused in the Langendorff mode and subjected to 45 minutes of ischemia and 30 minutes of reperfusion. Postischemic recovery was impaired in hypertrophied hearts, but addition of neutralizing anti-rabbit TNF-α antibody to cardioplegia and perfusate solutions restored postischemic function. This effect was mimicked by treatment with the ceramidase inhibitor
N
-oleoyl ethanolamine. TNF-α inhibition also was associated with faster postischemic recovery of phosphocreatine, ATP, and pH as assessed by
31
P nuclear magnetic resonance spectroscopy. Intracellular calcium handling, measured by Rhod 2 spectrofluorometry, demonstrated lower diastolic calcium levels and higher systolic calcium transients in anti-TNF-α treated hearts.

Conclusions

TNF-α is expressed in myocardium during compensated pressure-overload hypertrophy and contributes to postischemic myocardial dysfunction. Inhibition of TNF-α signaling significantly improves postischemic contractile function, myocardial energetics, and intracellular calcium handling.
Regression of Left Ventricular Hypertrophy After Surgical Therapy for Aortic Stenosis Is Associated With Changes in Extracellular Matrix Gene Expression
Authors: Walther Thomas , Schubert Andreas , Falk Volkmar , Binner Christian , Kanev Andreas , Bleiziffer Sabine , Walther Claudia , Doll Nico , Autschbach Rüdiger , Mohr Friedrich W.
Published: July 2021

Background

Regression of left ventricular hypertrophy (LVH) after surgical correction for aortic stenosis is not fully understood on the molecular level. The aim of this study was to examine whether there is an association between LVH regression and extracellular matrix (ECM) gene expression.

Methods and Results

A standard model of controlled LVH induction by supracoronary banding (A=baseline) was applied in 44 growing sheep (age, 6 to 8 months). Surgical correction to release the pressure gradient was performed 8.3±1 months later (B). The animals were killed after another 10.1±2 months (C). At all time points, hemodynamic evaluations and quantitative analysis of mRNA and protein expression for matrix metalloproteinases (MMP) and their tissue inhibitors (TIMP) was performed. Left ventricular mass index was 82±21 (A) versus 150±33 (B),
P
<0.01, and 78±18 g/m
2
(C),
P
<0.01. Left ventricular function and cardiac index remained stable. Myocardial fiber diameter index was 9.1±1.2 (A) versus 12.3±1.4 (B),
P
<0.01, and 8.4±1.3 μm/m
2
(C),
P
<0.01. In parallel to the development of LVH at B, gene expression was increased significantly for MMP-1, MMP-2, MMP-3, and MMP-9 and for TIMP-1 and TIMP-2 and decreased significantly for TIMP-3. After surgical correction (C), there was a complete regression of gene expression to baseline measures.

Conclusions

Controlled induction of compensated LVH leads to significant increase in ECM gene expression. The regression of LVH after surgical therapy is associated with complete regression of ECM gene expression. However, no cause-and-effect relation could be demonstrated.
Clinical and Angiographic Effects of Chronic Calcium Channel Blocker Therapy Continued Beyond First Postoperative Year in Patients With Radial Artery Grafts
Authors: Gaudino Mario , Glieca Franco , Luciani Nicola , Alessandrini Francesco , Possati Gianfederico
Published: July 2021

Background

This study was conceived to elucidate the clinical and angiographic effects of chronic calcium channel blocker therapy (CCCBT) continued after the first postoperative year in patients in whom the radial artery (RA) was used for myocardial revascularization.

Methods and Results

Patients who received RA grafts at our institution and who at 1 year had no scintigraphic evidence of ischemia in the RA territory or angiographic evidence of RA malfunction (n=120) were randomly assigned to continue (n=63) or suspend (n=57) the CCCBT with diltiazem (120 mg/d). After 5 years, all patients were reassessed clinically and by stress myocardial scintigraphy, and 87 of them (45 from the continued group that continued CCCBT and 42 from the group that suspended CCCBT) were restudied angiographically. No differences regarding either the clinical and scintigraphic results or the RA angiographic status were demonstrated between the 2 groups.

Conclusions

After the first postoperative year, the continuation of CCCBT does not affect RA graft patency or clinical and scintigraphic results.
Sustained Angina Relief 5 Years After Transmyocardial Laser Revascularization With a CO
2
Laser
Authors: Horvath Keith A. , Aranki Sary F. , Cohn Lawrence H. , March Robert J. , Frazier O. Howard , Kadipasaoglu Kamuran A. , Boyce Steven W. , Lytle Bruce W. , Landolfo Kevin P. , Lowe James E. , Hattler Brack , Griffith Bartley P. , Lansing Allan M.
Published: July 2021

Background

Although transmyocardial laser revascularization (TMR) has provided symptomatic relief of angina over the short term, the long-term efficacy of the procedure is unknown. Angina symptoms as assessed independently by angina class and the Seattle Angina Questionnaire (SAQ) were prospectively collected up to 7 years after TMR.

Methods

Seventy-eight patients with severe angina not amenable to conventional revascularization were treated with a CO
2
laser. Their mean age was 61±10 years at the time of treatment. Preoperatively, 66% had unstable angina, 73% had had ≥1 myocardial infarction, 93% had undergone ≥1 CABG, 42% had ≥1 PTCA, 76% were in angina class IV, and 24% were in angina class III. Their average pre-TMR angina class was 3.7±0.4.

Results

After an average of 5 years (and up to 7 years) of follow-up, the average angina class was significantly improved to 1.6±1 (
P
=0.0001). This was unchanged from the 1.5±1 average angina class at 1 year postoperatively (
P
=NS). There was a marked redistribution according to angina class, with 81% of the patients in class II or better, and 17% of the patients had no angina 5 years after TMR. A decrease of ≥2 angina classes was considered significant, and by this criterion, 68% of the patients had successful long-term angina relief. The angina class results were further confirmed with the SAQ; 5-year SAQ scores revealed an average improvement of 170% over the baseline results.

Conclusions

The long-term efficacy of TMR persists for ≥5 years. TMR with CO
2
laser as sole therapy for severe disabling angina provides significant long-term angina relief.
Neuroprotective Effect of Mild Hypothermia in Patients Undergoing Coronary Artery Surgery With Cardiopulmonary Bypass
Authors: Nathan Howard J. , Wells George A. , Munson Janet L. , Wozny Denise
Published: July 2021

Background

Neuropsychological deficits occur in 30% to 80% of patients undergoing heart surgery and are due in part to ischemic cerebral injury during cardiopulmonary bypass. We tested whether mild hypothermia, the most efficacious neuroprotective strategy found in laboratory studies, improved cognitive outcome in patients undergoing coronary artery surgery.

Methods and Results

Patients 60 years or older scheduled for coronary artery surgery were enrolled. During cardiopulmonary bypass, patients were initially cooled to 32°C then randomly assigned to rewarming to 37°C (control) or 34°C (hypothermic), with no further intraoperative warming. Testing was scheduled preoperatively and 1 week and 3 months postoperatively. Eleven tests were combined into 3 cognitive domains: memory, attention, and psychomotor speed and dexterity. A patient was classified as having a cognitive deficit if a decrease of ≥0.50 SD was realized in 1 or more domains. The incidence of cognitive deficits 1 week after surgery, which was the primary outcome, was 62% (

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) in the control group and 48% (

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) in the hypothermic group (relative risk 0.77,
P
=0.048). In the hypothermic group, the magnitude of deterioration in attention and in speed and dexterity was reduced by 55.6% (
P
=0.038) and 41.3% (
P
=0.042), respectively. At 3 months, the hypothermic group still performed better on one test of speed and dexterity (grooved pegboard). There was no difference in morbidity or mortality.

Conclusions

Our findings support a neuroprotective effect of mild hypothermia in patients undergoing coronary artery surgery and should encourage physicians and perfusionists to pay careful attention to brain temperature during cardiopulmonary bypass.
Abstract 578: Hex is Essential for Cardiac Myogenesis in Differentiating Embryonic Stem Cells
Authors: Kaneda Ruri , Liu Yu , Schwartz Robert J , Schneider Michael D
Published: July 2021

Background:
We previously demonstrated that Sox17, an Sry-box-containing transcription factor that interacts with the Wnt/ β-catenin pathway, is essential for cardiac myogenesis in differentiating embryonic stem (ES) cells. Sox17 shRNA blocks cardiac myogenesis and selectively impairs the induction of Hex, a member of the homeobox family of transcription factors, many of which are involved in developmental processes. However, whether Hex is a direct target of Sox17 or not and the function of Hex in mouse ES cell differentiation to cardiomyocytes have not been defined.

Hypothesis:

Hex is a direct target of Sox17, and

Hex is essential for cardiac myogenesis in ES cells.

Methods:
Cells were subjected to lentiviral transduction for a chimeric protein, contains Sox17 fused to protein A, using a protocol that reconstructs the native Sox17 expression pattern. Protein A-TEV-tagged Chromatin Immuno-precipitation (PAT-ChIP) technology was used to purify the DNA fragments bound to Sox17. Chromatin-immunoprecipitated DNA was subjected to PCR for promoter regions of Hex that contain putative Sox-binding motifs. Lentiviral vectors encoding shRNAs that knock down Hex were transduced into AB2.2 cells. Transduced cells, distinguished by expression of EGFP, were flow-sorted and subjected to embryonic body (EB) culture. Total RNA was extracted from EBs at 10 time points. Real-time QRT-PCR was carried out for representative genes related to mesoderm formation, mesoderm patterning, and cardiac myogenesis. Spontaneously beating EBs were scored.

Results:
Several Hex promoter regions containing predicted Sox17 binding sites were confirmed as potential direct targets of Sox17. The prevalence of beating EBs and the expression of cardiogenic transcription factors (Nkx2.5, Tbx5, Mef2c, Gata4 and myocardin) and cardiac structural genes (Ryr2 and α-MHC) both were suppressed by Hex shRNA. Hex shRNA did not impair the progressive down-regulation of Sox2 and Oct4 (master regulators of pluripotency) or the induction of Brachyury/T and Mesp1/2 (markers of primitive and precardiac mesoderm, respectively).

Conclusion:
Hex is potentially a direct target of Sox17, and is essential for cardiac myogenesis in differentiating ES cells at the stage of cardiac specification.
Abstract 593: Hypoxia is Present in the Macrophage-rich Center of Human Carotid Atherosclerotic Plaques
Authors: Sluimer Judith C , van Wanroij Job L , Groeneweg Matthijs , Wouters Bradly G , Daemen Mat J , Bijnens Ann-Pascale J
Published: July 2021

Intraplaque neovascularization is linked to plaque instability and thought to be stimulated by hypoxia. However, hypoxia has not been demonstrated yet in human atherosclerosis. The hypoxia marker pimonidazole was administrated intravenously 2 hours prior to carotid endarterectomy in 6 symptomatic patients to evaluate the presence of hypoxia. Subsequent immunohistochemistry of the operatively removed atherosclerotic plaques demonstrated the presence of hypoxia, especially in the macrophage-rich center of the lesions. Notably, two hypoxic gradients were observed:

hypoxia was very strong in the center of the plaque, but almost absent close to the main artery lumen and in the media.

hypoxia was most intense in segments with advanced atheroma and almost absent in segments containing only diffuse intimal thickening.

Hypoxia strongly correlated with CD68 immunoreactivity (ρ= 0.7, p=0.000), neovascularization (ρ= 0.6, p=0.000) and the presence of a thrombus (ρ= 0.4, p=0.009). In addition, hypoxia co-localized with expression of HIF1α and VEGF . To exclude that pimonidazole immunoreactivity in the atherosclerotic plaque was the result of surgery-induced ischemia, arterial wall segments were collected at two time-points: directly after incision of the carotid artery and directly following excision of the plaque. Pimonidazole immunoreactivity in these two pieces was not different, suggesting that hypoxia and pimonidazole adducts were already present in the plaques before surgery . To show that pimonidazole reactivity was hypoxia-specific and independent of reactive oxygen species, human THP-1 macrophages were exposed to normoxia (20% O
2
), hypoxia (0.2% O
2
) and/or H
2
O
2
(100 μM) in the presence of pimonidazole. Indeed, flow cytometry only showed pimonidazole-positive cells after hypoxic exposure. This is the first study proving direct evidence of the existence of hypoxia in advanced human atherosclerotic lesions, most prominently in the macrophage-rich center. Also, hypoxia was associated with the expression of HIF1α, VEGF and intraplaque microvessels, suggesting its involvement in the regulation of human intraplaque neovascularization.
Abstract 621: Attenuated Expression of Profilin-1 Confers Protection from Atherosclerosis in the LDL Receptor-null Mouse
Authors: Romeo Giulio R , Moulton Karen S , Kazlauskas Andrius
Published: July 2021

INTRODUCTION. Atherosclerosis-related events are a major cause of morbidity and death worldwide. The mechanisms underlying atherogenesis are not fully understood. We showed in previous studies that the actin-binding protein profilin-1 (pfn) was upregulated in atheroscle-rotic lesions and in endothelial cells (EC) treated with oxidized LDL (oxLDL).

HYPOTHESIS. In the present study, we tested the hypothesis that pfn levels play a role in early atheroma formation.

RESULTS. Since Pfn −/− mice die during embryonic development, we tested the role of pfn in atherogenesis by crossing adult Pfn +/− mice, which are viable and display a ∼50% reduction in pfn levels, into the Ldlr −/− mouse model of atherosclerosis. Atherosclerotic lesion burden was assessed in Pfn +/−Ldlr −/− (PfnHet) and Ldlr −/−control mice (PfnWT) fed an atherogenic high-cholesterol diet (HCD) for two months. Both males and females PfnHet exhibited a significant reduction in the percent lesion area in the descending aorta, when compared to PfnWT (females: 1.1 Â 27> 0.1 vs PfnWT 4.17 Â27> 0.49%, n=10; males: 1.34 Â 27> 0.22 vs PfnWT 3.4 Â 27> 0.36%, n=6). Similarly, aortic arch lesions were reduced in PfnHet (0.08 Â 27> 0.3 vs PfnWT 0.20 Â 27> 0.05 mm2, n=10). Total cholesterol and triglyceride levels were comparable in the two groups. Relevant atheroprotective changes were identified in PfnHet. When compared to PfnWT, aortas from PfnHet mice showed preserved eNOS activation, NO production and NO-dependent signaling. These changes were observed under HCD but not under a normal diet, thus indicating that pfn levels modified the response of the endothelium to atherogenic injury rather than its basal function. Similarly, knockdown of pfn in cultured aortic EC was protective against endothelial dysfunction triggered by oxLDL. Also, bone marrow-derived macrophages from PfnHet showed reduced internalization of oxLDL and oxLDL-induced inflammatory pathways, including activation of p38.

CONCLUSIONS. These studies demonstrate that pfn levels modulate critical processes for atherosclerotic lesion formation through combined endothelial- and macrophage-dependent mechanisms.
Abstract 623: Role Of Cd73-derived Adenosine In Atherosclerosis
Authors: Buchheiser Anja , Emde Barbara , Fischer Jens W , Schrader Jürgen
Published: July 2021

We recently reported that mice with targeted deletion of ecto-5′-nucleotidase (CD73) are characterized by enhanced platelet activation and increased adherence of monocytes to the endothelium. Wire-induced injury of the carotid artery resulted in enhanced neointima formation associated with increased macrophage content and VCAM-1 expression in CD73−/−mice. In order to study a possible modulation of atherogenesis and vascular inflammation by CD73-derived adenosine, we generated ApoE−/−/CD73−/− double mutant mice. Quantification and characterisation of atherosclerotic lesions was performed in WT, ApoE−/−, and ApoE−/− / CD73−/− mice on chow diet after 6 and 12 month, respectively, by macroscopic analysis of the descending thoracic aorta after oil red staining and by histological stainings for cholesterol, hyaloronic acid, and collagen in cryo sections of the aortic sinus. Immunohistological analysis of lesion morphology included primary antibodies for ICAM-1, VCAM-1, CD4, CD73, and CD11b. Determination of the plaque score by oil red staining revealed enhanced development of atherosclerotic lesions over the entire thoracic aorta after 6 month in the double mutant compared with ApoE−/− (2.5-fold increased, n=8, P<0.05). Atherosclerotic plaques in the aortic sinus were substantially enlarged as compared to ApoE−/− mice. Changes in extracellular matrix composition were not detected. However, we found enhanced VCAM-1 expression in ApoE−/−/CD73−/− mice after 6 month, which was accompanied by an increased infiltration of monocytes and macrophages but unchanged T-cells. We also noted that in atherosclerotic plaques of ApoE−/− mice the expression and activity of CD73 was significantly increased compared to WT. Measurements of cytokines in plasma support the notion of an increased inflammatory state in the double knockout. Interestingly, after 12 months all double mutant mice showed multiple scattered myocardial infarcts associated with myocardial hypertrophy and fibrosis. Our findings demonstrate that CD73-derived adenosine acts as an endogenous modulator protecting against chronic vascular inflammation and monocyte recruitment. Thus in the murine model, extracellular adenosine appears to limit the progression of atherosclerosis.
Abstract 684: Changes in Levels of High Density Lipoprotein Cholesterol Predict the Impact of Torcetrapib on Progression of Coronary Atherosclerosis: Insights from ILLUSTRATE
Authors: Nicholls Stephen J , Brennan Danielle M , Wolski Kathy , Kalidindi Srinivasa R , Moon Keon-Woong , Tuzcu E. Murat , Nissen Steven E
Published: July 2021

Background:
Administration of the CETP inhibitor torcetrapib does not slow the rate of progression of coronary atherosclerosis. The reason for the lack of therapeutic efficacy remains unknown. This analysis investigated the relationship between changes in HDL cholesterol (HDL-C) and LDL cholesterol (LDL-C) and atheroma volume in patients treated with torcetrapib.

Methods:
910 patients with angiographic coronary artery disease underwent IVUS imaging within a single coronary artery before and during 24 months of treatment with torcetrapib (n = 464) or placebo (n = 446) on a background of atorvastatin therapy. The relationship between changes in levels of HDL-C and LDL-C and both percent atheroma volume (PAV) and total atheroma volume (TAV) was evaluated in patients treated with torcetrapib.

Results:
Administration of torcetrapib raised HDL-C by 61% and lowered LDL-C by 20% when compared to atorvastatin alone. An inverse relationship was observed between changes in HDL-C and both PAV (r = −0.17, p < 0.001) and TAV (r = −0.17, p < 0.001). Patients with the highest level of HDL-C (> 87 mg/dL) had the lowest rate of progression of PAV (−0.7 v +0.7%, p = 0.0003) and TAV (−9.2 v −4.6 mm
3
, p = 0.09). The greatest elevation in level of HDL-C (> 80%) was associated with the lowest progression of PAV (−0.3 v +0.9%, p = 0.002) and TAV (−12.6 v −3.4 mm
3
, p = 0.0006). Patients undergoing regression (any reduction in PAV) had greater absolute levels (73 v 66 mg/dL, p = 0.02) and changes (59.5 v 48.3%, p = 0.02) of HDL-C. No difference in the impact of torcetrapib on changes in PAV (+0.3 v +0.1%, p = 0.34) and TAV (−9.1 v −9.3 mm
3
, p = 0.95) was observed in patients with baseline levels below or above 40 mg/dL. No relationship was observed between changes in LDL-C and either PAV (r = 0.06, p = 0.20) or TAV (r = 0.07, p = 0.12) in torcetrapib treated patients. On multivariate analysis, changes in levels of HDL-C independently predicted the impact of torcetrapib on progression of PAV (p = 0.007) and TAV (p = 0.004).

Conclusion:
Increasing levels of HDL-C from torcetrapib treatment were associated with a beneficial impact of torcetrapib on plaque progression. This is consistent with the generation of functional HDL particles and suggests other effects to be responsible for the lack of benefit of torcetrapib.
Abstract 696: Cardiosphere-derived Cells Engraft Long-term in Infarcted Mice and Preserve Left Ventricular Function
Authors: Smith Rachel R , Leppo Michelle K , Chimenti Isotta , Terrovitis John , Barth Andreas S , Kizana Eddy , Messina Elisa , Giacomello Alessandro , Abraham M. R , Marbán Eduardo
Published: July 2021

Cardiosphere-derived cells (CDCs) were grown from rat hearts and percutaneous endomyocardial adult human biopsy specimens. Rat CDCs plated as single cells formed clones with a doubling time of 42.2 ± 0.7 hours (n = 9). Clones from rat CDCs divided steadily for 27 days before proliferation spontaneously slowed and morphological changes occurred in most cells. After 56 days, rat clonal populations contained a small fraction of c-Kit
+
cells as determined by flow cytometry, and large subsets of cells expressing cardiac troponin I, α-smooth muscle actin, and von Willebrand factor as determined by immunofluorescence, indicative of their multipotentiality
in vitro
. To assess therapeutic potential, acute myocardial infarcts (MIs) were created in immunodeficient mice and actively proliferating polyclonal human CDCs were injected into the border zone. Echocardiographic left ventricular function, histological examination, and immunofluorescence served as endpoints. CDC-injected animals showed no significant deterioration in ejection fraction (EF) from 2 days (EF = 45.2 ± 4.8%) to 6 weeks post-MI (EF = 40.2 ± 4.5%, n = 7, p = NS), in contrast to fibroblast-injected control animals (EF = 42.8 ± 4.3% at 2 days vs 27.3 ± 4.0% at 6 weeks, p < 0.01). At the 6 week endpoint, the CDC group had thicker infarct walls as measured histologically compared to the fibroblast group (0.26 ± 0.03mm vs 0.12 ± 0.01mm, n = 5, p < 0.01). CDC engraftment was determined by immunofluorescence using a human-specific antibody. CDCs stably engrafted for up to 6 weeks and could be found distributed primarily throughout the infarct (57 ± 3% of engrafted CDCs, n = 5 animals), as well as the border zone (30 ± 5%) and viable tissue (13 ± 3%). After 6 weeks, CDCs within the infarct had formed small myocytes with little cytoplasmic cardiac troponin I, while CDCs within the viable myocardium had formed large myocytes with well-defined sarcomeric organization. We conclude that CDCs are clonogenic and spontaneously multipotent
in vitro
and capable of preserving heart function in a mouse infarct model. Functional preservation is presumably due in part to maintenance of infarct wall thickness, likely secondary to stable CDC engraftment within the infarct, as well as the formation of morphologically mature myocytes throughout the non-infarcted tissue.
Abstract 713: S 18886 Inhibits Thromboxane A
2
Receptor-dependent Tissue Factor Expression, Procoagulant Activity And NADP(H) Oxidase Activation In Stimulated Endothelial Cells
Authors: Del Turco Serena , Basta Giuseppina , Lazzerini Guido , Chancharme Laurent , Lerond Laurence , De Caterina Raffaele
Published: July 2021

Background
Tissue factor (TF) expression and surface exposure are key events in thrombosis, likely contributing to clinical events in vascular disease. Thromboxane (TX)A
2
, an unstable metabolite of arachidonic acid released from vaious cell types, is known for its pro-aggregating and vasoconstrictor properties. Cellular effects of TXA
2
are effected through the TP (TX-prostaglandin endoperoxide) receptor, also expressed in endothelial cells (EC). The TP receptor antagonist S 18886 (Terutroban) demonstrated antithrombotic and antiatherogenic effects in activated EC. As the underlying molecular mechanisms are largely unexplored, we studied the effects of TP agonism and of antagonism on TF expression and procoagulant activity in human umbilical vein endothelial cells (HUVEC), and signal transduction pathways involved.

Methods and Results
HUVEC ± 30 min pretreatment with the TP antagonist S 18886 were stimulated with the TP receptor agonist U 46619 or TNF-α for 6 hours. TF total expression and surface exposure were assessed by enzyme immunoassays, and TF-dependent procoagulant activity by the generation of Factor Xa. HUVEC exposed to U 46619 featured a concentration-dependent increase in TF total expression and surface exposure. These were associated with enhanced procoagulant activity. S 18886 (1 μmol/L) significantly reduced U 46619 (1 μM)-induced TF expression (−20% ± 7%, P<0.05) and procoagulant activity (−32% ± 11%, P<0.05). Interestingly, S 18886 (1 μmol/L) prevented the increase of TF expression after TNF-α (20 ng/mL) stimulation (−25% ± 9%, P<0.05). Both U 46619- and TNF-α-induced TF expression were mediated by the increase of intracellular reactive oxygen species (ROS), and this was inhibited by S 18886 (−44% ± 6% and −24% ± 5% P<0.05, respectively). S 18886 decreased the membrane association of p47-phox component of NADP(H) oxidase, accounting for the reduced production of ROS.

Conclusions
Our results show that endothelial TP receptor mediates TF expression, surface exposure and activity stimulated both by TP agonists and by TNF-α. This occurs through NADP(H) oxidase activation and the consequent generation of ROS. These procoagulant and oxidant pathways are inhibited by the TP receptor antagonist S 18886.
Abstract 737: IKACh Dominantly Increases under the Condition of Atrial Electrical Remodeling: Pharmacological Consideration Using the Selective IKACh Blockers in Canine Atrial Tachypacing Model
Authors: Hashimoto Norio , Matsumoto Ryo , Ishiwata Norihisa , Yamashita Toru , Tsuruzoe Nobutomo
Published: July 2021

Back ground and purpose:
It is well-known that the increased vagal tone is a trigger of atrial fibrillation (AF). In dogs, vagal stimulation shortens atrial effective refractory period (ERP), increases ERP dispersion and promotes AF, possibly via the activation of the atrial acetylcholine-activated potassium channel. Recently, we have reported the blockers of the acetylcholine-activated potassium current (IKACh) terminated AF in canine paroxysmal AF model. However, the pathophysiological role of IKACh in the remodeled atrium seen in persistent AF patients remains unclear. The aim of this study is to evaluate the effects of the selective IKACh blockers, tertiapin and NIP-151 in the remodeled atrium induced by atrial-tachypacing (AT).

Methods and results:
The effects of tertiapin and NIP-151 on atrial ERP were investigated before and after 1 week of AT. Tertiapin (0.03 mg/kg, i.v.) and NIP-151 (0.3 mg/kg, i.v.) significantly prolonged the atrial ERP even before AT. The shortened atrial ERP which is associated with the electrical remodeling, was induced by AT (400 bpm) over 1 week. After AT for 1 week, the effects of tertiapin and NIP-151 significantly enhanced the prolongation of atrial ERP compared with those before AT. To evaluate whether a muscarinic M2 receptor and/or adenosine A1 receptor activates IKACh in remodeled atrium, we tested the effects of M2 receptor antagonist AF-DX116 (0.3 mg/kg, i.v.) and A1 receptor antagonist DPCPX (0.3 mg/kg, i.v.) in this model. Unlike the selective IKACh blockers, the effects of these drugs were not affected by AT for 1 week.

Conclusion:
Our results suggest that the constitutively activated IKACh, which is not associated with M2 receptor and/or A1 receptor, increases under the condition of atrial electrical remodeling. Therefore, the selective IKACh blockers such as tertiapin and NIP-151 might be useful for the treatment of persistent AF.
Abstract 740: Statin Prevents Structural and Electrical Atrial Remodeling in Rat Hypertensive Heart Failure Induced by Chronic Inhibition of NO Synthesis
Authors: Okazaki Hidetoshi , Minamino Tetsuo , Wakeno Masakatsu , Tsukamoto Osamu , Kim Jiyoong , Takashima Seiji , Mochizuki Naoki , Kitakaze Masafumi
Published: July 2021

Background: The prevalence of atrial fibrillation (AF) increases in patients with hypertension and heart failure in which endothelial function is impaired. Oxidative stress in atrial tissues is involved in the development of AF. Statins have pleiotropic effects including antioxidant effects. Thus, we developed hypertensive heart failure in rats by the chronic inhibition of NO synthesis and we investigated the role of the statin in atrial remodeling.

Methods and Results: Ten-week-old male Wistar-Kyoto rats were randomly divided into four groups: the control (no treatment), the L-NAME (received L-NAME, an inhibitor of NO synthase, 1 g/L in drinking water), the L-NAME+atorvastatin (L(a low dose)) (5 mg/kg/day) and the L-NAME+atorvastatin (H(a high dose)) (20 mg/kg/day). Chronic inhibition of NO synthesis increased systolic blood pressure (control group: 138±5 mmHg; L-NAME group: 212±8 mmHg L+atorvastatin (L) group: 210±6 seconds , L+atorvastatin (H): 208±6 seconds) and decreased LV dP/dt max/LVSP (control group: 54±3, L-NAME group: 36±8, L+atorvastatin (L) group: 40±3, L+atorvastatin (H) group: 38±6 1/second), whereas co-administration of atorvastatin did not affect them. The sustained duration of AF was always induced by transesophageal burst pacing (The pacing pulse used for induction of AF was rectanglar in shape, of 60V and 6ms-width. The atrium was paced at a cycle length of 12ms (83Hz) for 30seconds) and it was prolonged by L-NAME, which was prevented by atorvastatin in a dose-dependent manner (control: 8.8 ± 1.0 seconds, L-NAME: 20.7 ± 3.0 seconds, L+atorvastatin (L): 12.8 ± 3.2 seconds , L+atorvastatin (H): 8.8 ± 2.6 seconds). The chronic inhibition of NO synthesis increased the extent of fibrosis and markers of oxidative stresses such as proteins modified with 4-hydroxy-trans-2-nonenal and p47phox and rac1 in left atrial tissue, either of which was prevented by atorvastatin.

Conclusion: Atorvastatin attenuates oxidative stresses in atrium and prevents atrial electrical and morphological remodeling in rat hypertensive failing hearts without hemodynamic changes. Statin may be beneficial in patients with coronary heart disease and atrial fibrillation, and may contribute to the prevention of the onset of heart failure.