bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 2594: Coronary Multidetector Computed Tomography in the Prognostic Assessment of Patients with Equivocal or Mildly Abnormal Non-Invasive Cardiac Stress Tests
Authors: Azevedo Clerio , Spotti Mariane , Bezerra Sabrina , Hadlich Marcelo , Villacorta Humberto , Pereira Carlos , Pontes Alvaro , Junior Plinio , Souza Olga , Albuquerque Denilson , Moll Jorge
Published: July 2021

Background:
Patients with low or moderate pre-test probability of significant coronary artery disease (CAD) and equivocal or mildly abnormal non-invasive cardiac stress tests represent a frequent management challenge. Coronary multidetector computed tomography (MDCT) has been shown to have excellent diagnostic accuracy to exclude the presence of significant CAD.

Methods:
The study included 218 patients (mean age 59±12 years, 60% male) with equivocal or mildly abnormal exercise electrocardiography (n=93), stress SPECT perfusion scans (n=121), stress echocardiography (n=3) and stress cardiac MRI (n=1). Patients were either asymptomatic (n=113) or had atypical chest pain (n=105). All patients underwent contrast-enhanced 64-slice MDCT coronary angiography and datasets were evaluated for the presence of coronary atherosclerotic plaques and significant coronary artery stenosis. Patients were followed for 8±3 months and the endpoints evaluated were: cardiac death, myocardial infarction, revascularization procedure performed >3 months after MDCT coronary angiography and unstable angina requiring hospitalization.

Results:
MDCT coronary angiography was either normal (n=90; 41%), demonstrated non-obstructive coronary atherosclerotic plaques (n=66; 30%) or exhibited significant coronary stenosis (n=62; 29%). Event-free survival was 100% for patients with normal coronary angiography, 98% for patients with non-obstructive plaques and 92% for patients with coronary stenosis (log-rank test P=0.01). One patient with a non-obstructive plaque involving the left main coronary artery died following an AMI (hazard ratio, 0.38; 95% confidence interval, 0.04 to 3.24). Among patients with coronary stenosis, 3 underwent revascularization procedures and 2 died (hazard ratio, 12.59; 95% confidence interval, 1.47 to 107.86).

Conclusion:
Among patients with equivocal or mildly abnormal non-invasive cardiac stress tests, a normal MDCT coronary angiography is associated with a very low risk for subsequent cardiac events. Further studies are necessary to determine the clinical significance of non-obstructive atherosclerotic plaques detected by MDCT coronary angiography in this patient population.
Abstract 2600: Serum Proteomics Identifies Vitamin D-Binding Protein And Prothrombin As Novel Fingerprints of Coronary Thrombosis in Patients with STEMI
Authors: Gasparri Cosimo , Curcio Antonio , Gaspari Marco , Mercurio Paola , Vicinanza Carla , Galuppo Valentina , Leone Angelo , Cavaliere Anna Lucia , Niola Aglaia , Boncompagni Duino , Torella Daniele , Cuda Giovanni , Indolfi Ciro
Published: July 2021

One of the intriguing possibilities offered by proteomics analysis is to define new diagnostic and prognostic biomarkers of coronary artery disease. Accordingly, the aim of the present study was to analyze modifications in the serum proteome after acute myocardial infarction. Serum samples were collected from patients (age 63.8±12.6) with ST-Elevation Myocardial Infarction (STEMI) at 2–11 hours after the onset of typical chest pain and before standard therapy was initiated. The control group included 10 age- and sex-matched normal donors. The serum samples were processed to obtain albumin- and IgG-depleted serum. Then, isotope-coded affinity tag (ICAT) method was employed to label cysteine residues and liquid chromatography-Tandem Mass Spectrometry (LC-MS/MS) analysis was performed to measure the labelled proteins. Ten out of 300 defined and analyzed proteins were identified in 100% of the samples. Interestingly, haptoglobin, alpha-1-antitrypsin and ceruloplasmin were significantly increased in the samples from patients with acute STEMI (N=10) compared to controls (N=10). These data well reproduce similar findings reported in recent studies. However, two novel proteins were identified in patients with AMI. Remarkably, we observed a significant increase of vitamin D-binding protein precursor (VDB) and heavy chain prothrombin precursor in the serum from acute STEMI patients compared to control donors. Western blot analysis confirmed the higher amount of the latter two proteins after STEMI. Interestingly, fresh thrombotic plaques, obtained during primary angioplasty, showed high expression of VDB and prothrombin by RT-PCR and immunohistochemistry, postulating a potential role of VDB and prothrombin in coronary plaque instability and thrombosis. In additional studies in
ex vivo
human platelets VDB, as well as prothrombin, significantly increased ADP-induced platelet aggregation. In conclusion, the serum proteomics analysis employed in this study was able to identify VDB and prothrombin protein variation as novel indicators of acute STEMI. These data could be relevant to establish specific proteomics-based serum fingerprints for diagnosis and prognosis of acute coronary syndromes.
Abstract 2602: Elevated Serum Neopterin Levels and Adverse Cardiac Events in Patients with Non-ST-Segment Elevation Acute Coronary Syndrome
Authors: Kaski Juan Carlos , Consuegra-Sanchez Luciano , Fernandez-Berges Daniel J. , Cruz-Fernandez Jose M , Garcia-Moll Xavier , Marrugat Jaume , Mostaza José
Published: July 2021

Objectives: We sought to assess whether plasma neopterin predicts adverse clinical outcomes in patients with NSTEACS. Background: Circulating C reactive protein (CRP), a marker of inflammation, correlates with events in patients with non-ST-segment elevation acute coronary syndrome (NSTEACS). High neopterin levels - a marker of macrophage activation - predict cardiovascular events in stable angina patients but their prognostic role in NSTEACS has not been systematically evaluated.

Methods: We prospectively assessed 397 patients (74 % men) admitted with NSTEACS: 169 (42.5%) had unstable angina and 228 (57.5%) non-ST-segment elevation myocardial infarction (NSTEMI). Blood samples for neopterin and CRP assessment were obtained at admission. TIMI risk score was also assessed among other clinical and biochemical variables. The study end point was the composite of cardiac death, acute myocardial infarction and recurrent angina at 180-days.

Results: Baseline neopterin concentrations (nmol/L) were similar in unstable angina and NSTEMI patients (8.3 [6.5–10.6] vs 8.0 [6.2–11.1], p = 0.54). Fifty-nine patients (14.9 %) had events during follow-up (highest third (%) 21.5 vs 1
st
and 2
nd
thirds 11.5, log rank 7.341, p = 0.007). On multivariable hazard Cox regression, only neopterin (highest vs 1
st
and 2
nd
thirds, HR 2.15, 95 % CI [1.21–3.81]) was independently associated with the combined endpoint.CRP levels, however, were not significantly different in patients with events compared to those without events (adjusted HR = 0.98, p = 0.89, 95% CI 0.80 –1.21).

Conclusion: Increased neopterin levels are an independent predictor of 180-day adverse cardiac events in patients with NSTEACS.
Abstract 2620: C1q Exacerbates Mitochondrial Dysfunction Without Activation Of The Terminal Complement In Neonatal Mice With Hypoxic-ischemic Brain Injury.
Authors: Ten Vadim S , Caspersen Casper , Baalasubramanian Sivasankar , Morgan Paul , Botto Marina , Starkov Anatoly , Polin Richard
Published: July 2021

Deletion of C1q protects developing brain against hypoxia-ischemia (HI) (Ten V et al; 2005).

Hypothesis. C1q mediates HI-brain injury by:

Activation of terminal complement or/and

Exacerbation of mitochondrial dysfunction.

Hypothesis (1) P7 WT (C57Bl/6j) pre-treated with vehicle or sCD59; progenies of C1q+/-, Factor B/C2-/-/-/- inter-mating were subjected to HI: ligation of right carotid artery + hypoxic exposure. At 24 hr of reperfusion the extent of damage, cerebral deposition of C1q, C3, iC3b and C9 were assessed. Hypothesis (2) In C1q-/-and WT mice cerebral ATP-content, mitochondrial O2-consumption rate, H2O2-production and membrane potential (î»m) were studied immediately after HI. At 12 hr electron microscopy for co-staining of C1q and gC1qR/p33 in neurons was performed. WT and C1q-/- cortical and granule neurons in culture were subjected to glutamate or energy failure stress (EFS), glucose deprivation and exposure to 5 mM Na azide. At 24 hr after stress cellular viability, C1q protein and C9 mRNA expression were examined.

Results. C1q-/- mice were significantly protected against HI compared to +/+ counterparts. This was associated with robust attenuation of deposition of C3, iC3b and C9 in brain. However, no protection was detected in FB/C2-/ -/ -/ - and sCD59-pretreated mice, although C9-deposition in the injured brain was significantly decreased compared to controls. C1q-/ - mice exhibited a stunning preservation of ATP in the ischemic brain immediately after HI. This was associated with higher O2-consumption rate in state 3 and significantly (two-folds) less production of H2O2 by C1q-/ - mitochondria compared to WT-counterparts without difference in the î»m. In WT-mice HI resulted in intraneuronal, and intramitochondrial accumulation of C1q and gC1qR/p33 only in the ischemic hemisphere. C1q-/ - vs WT cultured neurons were significantly protected against excitotoxic and EFS in the absence of C9-mRNA in cellular lysate.

Conclusion. C1q mediates HI-injury. Terminal complement activation has no role in C1q-mediated neuronal damage. The presence of C1q is associated with significantly increased mitochondrial ROS-production in HI-brain. This may represent a novel mechanism for HI-neurodegeneration.
Abstract 2644: High Prevalence of a Novel Conduction Pattern Around the Coronary Sinus in Cavotricuspid Isthmus Dependent Right Atrial Flutter
Authors: yamaguchi yoshio , Tsugawa Hiroichi , Fujioka Nakaba , Kaseno Ken-ichi , Kitayama Michihiko , kajinami Kouji
Published: July 2021

Objective
: We tested our hypothesis that, in atrial flutter (AFL) dependent on the cavotricuspid isthmus (CTI), lower loop reentry (LLR) is the common pathway route at the coronary sinus (CS) posterior site, and thus, dual loop reentry (DLR) is a common circular pattern.

Methods and result
s: We studied 25 patients with CTI-dependent AFL, 16 with chronic counterclockwise atrial flutter (CCW-AFL) and 9 with clockwise atrial flutter (CW-AFL) and determined the precise reentry circuitry, especially for conduction patterns around the CS orifice, using electroanatomical mapping. We measured post pacing interval and tachycardia cycle length during entrainment from sites within the flutter circuit. In 16 of the 25 CCW-AFL patients, the CS anterior pacing site was within the AFL circuit in 13. The CS anterior pacing site was within the AFL circuit in 6 of the 9 CW-AFL patients. In 8 each of 16 CCW-AFL and 9 CW-AFL patients, both the CS anterior and posterior sites were within the AFL circuit. Results of 3-Dimensional (3D) activation mapping suggest that all of these patients had a DLR circuit, and that CS posterior conduction broke through the eustachian valve/ridge.

Conclusion
: CS posterior conduction consisted of the flutter circuit and appeared to be critical for maintaining AFL. Almost all AFL patients had DLR formed within the LLR or the superior RA circuit constituted from CS posterior conduction and in the anterior loop around the tricuspid annulus.
Abstract 2663: How Do Cardiologists and Cardiothoracic Surgeons Treat Asymptomatic Mitral Regurgitation in Clinical Practice? An International Survey
Authors: Harris Kevin M , Pastorius Catherine A , Harwood Eileen M , Duval Sue , Hirsch Alan T , Carabello Blase A
Published: July 2021

Background:
Severe mitral regurgitation (MR) is known to be associated with adverse clinical outcomes. Thus, consensus-derived, evidence-based practice standards (e.g., ACC/AHA Guidelines for Management of Valvular Heart Disease) have been published. Yet, no data exist to describe whether physicians follow such standards in clinical practice for asymptomatic pts with MR.

Methods:
A random sample of cardiovascular specialists were surveyed by email and asked to complete 26 items that encompassed MR-related practice patterns.

Results:
1035 physicians completed the survey (68% response rate) and the sample included adult cardiologists (95%) and cardiac surgeons (5%) who practice in the USA (84%), Canada (6%), and other nations (10%). When asked ``Do you refer asymptomatic patients with severe MR and normal LV function for MV repair?”, 28% responded yes/almost always, and 11% responded no/ rarely. There was geographic & specialty-dependent variation in practice (Table

). Patient referral for mitral surgery was based on risk markers, such as atrial fibrillation (18%) and pulmonary hypertension (17%) and anatomic factors (e.g., flail valve, 18%) and clinical variables (e.g., increased likelihood of repair, 19%). Most physicians (65%) use medications to delay progression of MR, with ACE-inhibitors utilized by 57%. Isolated posterior prolapse repair was repaired successfully >85% at their hospital by 61% (60% for cardiologists vs. 82% for surgeons, p=0.004). 28% of respondents almost always quantitate MR using effective regurgitant orifice area, while 30% rarely or never do so.

Conclusions:
Cardiologists frequently refer asymptomatic MR patients for mitral reparative surgery, but referral is often prompted by factors beyond those included in current guidelines. Practice patterns vary by physician type and by geographical location. Medications are frequently used to treat asymptomatic individuals with MR, in the absence of documented evidence of efficacy.
Abstract 2666: Insulin-like Growth Factor-I And Perfused Culture Independently Enhance Formation Of Tissue Engineered Cardiac Grafts
Authors: Cheng Mingyu , Moretti Matteo , Engelmayr George C , Freed Lisa E
Published: July 2021

Tissue engineered cardiac grafts (TECG) have been proposed as a platform for systematic in vitro studies of complex stimuli that occur in vivo, and as a means to repair damaged or congenitally defective myocardium. However, clinical application of TECG is currently limited by suboptimal cardiomyocyte (CM) survival, differentiation, and contractility. We tested the hypothesis that insulin-like growth factor-I (IGF) and perfused culture can enhance formation of TECG.

Method:
Three-dimensional porous scaffolds were placed individually in either Petri dishes or the chamber of a novel modular, perfused bioreactor, seeded with primary neonatal rat heart cells, and cultured in 10 mL of media supplemented or not with 100 ng/mL of IGF for 8 days. Two-factor ANOVA was used to assess significant effects of IGF and perfusion acting individually and in concert.

Results:
IGF significantly enhanced contractile properties of TECG compared to unsupplemented controls, as assessed by contractile amplitude (p<0.05) and excitation threshold (p<0.01); IGF also significantly increased the amount of cardiac troponin-I (Tn-I) in TECG, as assessed by Western blot (p<0.01). Perfusion significantly enhanced CM survival and metabolic activity in TECG compared to non-perfused controls, as assessed by TUNEL (p<0.01) and MTT (p<0.01) assays. CM elongation and myofibrillogenesis were readily observed in perfused TECG but were rare without perfusion, as assessed by immunostaining for cardiac Tn-I. Spontaneous contractility was present only in perfused TECG, although contractions could be induced by electrical field stimulation of TECG cultured both with and without perfusion. In concert, perfused culture in IGF-supplemented media significantly increased contractile amplitude by 450% and decreased excitation threshold by 50%, as compared to static culture in unsupplemented media. Effects of perfused culture and IGF on TECG were significant (p<0.0001 for amplitude; p<0.005 for threshold), independent, and additive, suggesting at least partially different cell activation mechanisms.

Conclusion:
Insulin-like growth factor-I and perfusion culture can improve the viability, differentiation, and contractility of cardiomyocytes in tissue engineered cardiac grafts.
Abstract 2669: The Use of Granulocyte-Colony Stimulating Factor in Angina Patients to Stimulate Neovascularization: the GAIN I study
Authors: Kovacic Jason C , Macdonald Peter , Feneley Michael P , Muller David W , Ma David , Tao Helen , Freund Judith , Milliken Sam , Dodds Anthony , Moore John , Itescu Silviu , Graham Robert M
Published: July 2021

Background
G-CSF is a novel therapy for ischemic heart disease (IHD), but its safety and efficacy in acute or ‘no option’ refractory IHD (R-IHD) remains unclear. Also, the few completed studies generally did not adapt G-CSF to IHD patients but merely administered G-CSF according to usual hematological practice. To address these issues we evaluated the safety and efficacy of G-CSF therapy in 20 patients (18 males, 2 females, mean age 62.4) with R-IHD. Three approaches were incorporated to enhance the efficacy of G-CSF in R-IHD:

Repeated, controlled myocardial ischemia was induced during G-CSF therapy to activate myocardial chemokine expression as a homing signal for mobilized angioblasts;

Two cycles of G-CSF were administered to enhance the likelihood of clinically meaningful angiogenesis;

During the second cycle of G-CSF an intracoronary infusion of CD133+ cells was performed.

Methods
After baseline cardiac assessment (CA) (angina questionnaire, exercise stress test (EST), nuclear Sestamibi (MIBI) and dobutamine stress echocardiographic (DSE) imaging), patients received open-label G-CSF commencing at 10μg/kg s/c for 5 days, with an EST on days 4 and 6 (to facilitate angioblast trafficking). After 3 months CA and the same regimen of G-CSF +ESTs were repeated but in addition, leukapheresis and a randomized double blinded intracoronary infusion of CD133+ or unselected cells were performed. Final CA was 3 months thereafter.

Results
Eight events fulfilled pre-specified adverse event (AE) criteria, but despite the poor outlook and co-morbidities of R-IHD patients there were no deaths or AEs resulting in long-term sequelae. Administration of 2 cycles of G-CSF resulted in step-wise improvements in angina frequency, quality of life, EST performance and Duke treadmill score (all p < 0.005). Pre-specified MIBI and DSE results trended towards improvement (p > 0.1), while a composite post hoc computation indicated improved ischemia/perfusion compared to baseline (p = 0.025). Intracoronary infusion of CD133+ or unselected cells was safe but neither enhanced the response to G-CSF.

Conclusions
Administering G-CSF to R-IHD patients may be performed safely and shows promise as a therapy for debilitating angina. A phase II/III study of this therapy is warranted.
Abstract 2672: Serial in vivo Non-invasive Imaging of Intramyocardially Injected Autologous Mesenchymal Stem Cells, Modified for Transgene Expression of Positron-Emission Tomography (PET) Reporter in Porcine Myocardial Infarction
Authors: Gyongyosi Mariann , Blanco Jeronimo , Marian Terez , Petnehazy Ors , Hemetsberger Rayyan , Pavo Imre , Font Gusztav , Toth Lajos , Huber Kurt , Glogar Dietmar
Published: July 2021

Objective. The aim of our study was to elaborate an in vivo tracking method of the intramyocardially injected msenchymal stem cells (MSCs), modified for transgene expression of trifusion protein (lentiviral vector, expressing renilla luciferase /RL/, red fluoroscein protein /RFP/ and herpes simplex truncated thymidine kinase /tTK, positron emmission tomography PET-reporter gene/) using serial PET imaging in pig myocardial infarction (MI).

Methods. Bone marrow (100 ml) was harvested from pigs immediately before induction of MI by percutaneous balloon occlusion of the LAD followed by reperfusion. The MSCs were selected and cultivated. The lentiviral vector LV-RL-RFP-tTK was inoculated into the MSCs under control of CMV promoter. The cells with the highest fluorescence intensity (after achieving appr. 50% transfection efficacy) were sorted, and tracked in vitro by PET using 9-(4-[18F]fluoro-3-hydroxymethylbutyl)-guanine (18FHBG). The transfected MSCs (at least 3 mio MSCs/ pigs) were then injected direct intramyocardially using NOGA electromagnetic guidance in pigs in 10 locations of the infarct border zone (min. 0.3 million cells/injection), followed by PET imaging 30 hours and 7 days later, after intravenous injection of 5 mCi 18FHBG.

Results. The in vitro 18FHBG uptakes of the transgene modified MSCs by PET were 10 times larger than the control JY human B-lymphoblasts and T lymphocytes. The minimum number of the cells detectable with PET was 0.2 million. MRI of the pigs revealed a mean global EF of 47+/-3.5%. PET imaging displayed diffuse distribution of the injected MSCs with high activity of the PET tracer in the anterior wall and septum at 30h, and less tracer activity in the injections sites with diffuse distribution in the pericardium and pleura indicating the wandering of the living cells at 7 days. PET imaging did not show 18FHBG accumulation in the infarcted heart of the control animals. Myocardial histology with RL and RFP staining confirmed the distribution of the injected MSCs through an elongated track around the injected area, 9 days after delivery.

Conclusion. In vivo tracking of gene-modified porcine MSCs by PET imaging is feasible and allows serial noninvasive imaging of homing and propagation of MSCs in pigs after MI.
Abstract 2693: Mitral E/E’ underestimates Pulmonary Capillary Wedge Pressure During Exercise.
Authors: Marchandise Sébastien , D’Hondt Anne-Marie , Gurne Olivier , Vancraeynest David , Gerber Bernhard , Vanoverschelde Jean Louis , Pasquet Agnes
Published: July 2021

Background.
Previous studies have shown that resting LV filling pressures can be estimated noninvasively by use of the ratio of the early diastolic transmitral filling velocity (E) to the early diastolic septal tissue velocity (E’). Yet, limited data exist regarding the accuracy of this measurement during exercise. In this study, we therefore sought to evaluate the possible value of exercise E/E’ for predicting invasively measured pulmonary capillary wedge pressure (PCWP).

Methods.
22 patients (57 ± 15 years, 10 males) with heart failure (n=14), valve disease (n=6) or pulmonary hypertension (n=2) underwent right heart catheterization during symptom limited bicycle exercise. For each patient, PCWP and Doppler measurements of E/E’ were acquired in left lateral decubitus, after 5 min of sitting and during the last minute of each exercise stage.

Results.
With exercise, heart rate increased from 78 ± 17 bpm to 118 ± 21 bpm, as did systolic blood pressure (from 128 ± 29 to 169 ± 30 mmHg, p<0.001), PCWP (from 15 ± 6 to 24 ± 9 mmHg, p<0.001), E velocity (from 84 ± 34 to 111 ± 41 cm.s
-1
p<0.001) and septal E’ (from 6.2 ± 2.7 to 9.0 ± 4.3 cm.s
-1
p<0.01). At rest, in both recumbent and sitting positions, E/E’ correlated well with PCWP (solid circle, y = 0.7856 X + 4.2084, r = 0.72). During exercise, E/E’ also correlated with PCWP (open circle, y = 0.5253x + 1.7168, r = 0.64). The relationship was nonetheless shifted downward and to the right compared to rest.

Conclusion.
While E/E’ correlates with PCPW both at rest and during exercise, the relationship between these 2 parameters is different under these 2 conditions. Therefore, E/E’ values defining elevated LV filling pressures at rest cannot be used during exercise.
Abstract 2701: Late Gadolinium Enhancement Cardiovascular Magnetic Resonance Predicts Lack of Functional Recovery in Patients with New Onset Heart Failure Undergoing Optimal Therapy
Authors: Romaguera Rafael , Nadal-Barangé Mercedes , Estornell Jordi , Jacas Victoria , Perez-Bosca Leandro , Corbi Miguel , Trigo Alberto , Laynez Ana , Echánove Ildefonso , Ridocci-Soriano Francisco
Published: July 2021

Background
: Some patients with heart failure may have a marked improvement in left ventricular function (LVF) even in the absence of optimized drug therapy. Previous data shows that the proportion of patients matching the criteria for device implantation dropped significantly after 6 months on optimal medial therapy. However the predictors of recovery in LVF are not well understood.

Objetive
: We evaluated the feasibility of using late gadolinium enhancemnet cardiovascular magnetic resonance (LGE-CMR) to predict the improvement in LVF in new onset heart failure (AHF) patients on optimized medical therapy.

Methods
: Seventy six patients admitted with AHF and EF < 35% underwent LGE-CMR. Baseline and follow-up echocardiography was performed to assess functional recovery. We evaluated change in the proportion of patients who satisfied criteria for device implantation (EF< 35%) after 7 month on optimal therapy.

Results
: During follow-up 81% were treated with B-Blockers, 91% with ACEI and 33% with spironolactone. Twenty two patients (29%) had late gadolinium enhancement. Change in LVF was significantly hgher in patients who did not show LGE-CMR (p< 0.006). Al follo-up 55% of patients not satisfied criteria for device implantation as they developed functional recovery. Multvariate analysis showed that LGE-CMR (OR 0.10, CI 0.02–0.48, p =0.004), left bundle branch block (OR 0.14 CI 0.03–0.70, p=0.0017) and betablockers (OR 5.94 CI 1.12–31.40, p=0.006) were indepent predictors of functional recovery.

Conclusions
: The proportion of patients with AHF who satisfied criteria for device implantation as a primary prevention, dropped signifcantly after 7 months on optimal medial treatment. Late gadolinium enhancement CMR is a useful tool to identify these patients
Abstract 2732: Interacting Blood Pressure Loci in the Stroke-Prone Spontaneously Hypertensive Rat.
Authors: Graham Delyth , McBride Martin W , Gilday Kirsten , McClure John D , Dominiczak Anna F
Published: July 2021

Background:
In a previous genome wide linkage study we identified blood pressure quantitative trait loci (QTL) mapping to rat chromosome 2 and chromosome 3 in an F2 cross derived from SHRSP and WKY strains. We also identified a significant interaction between loci on chromosomes 2 and 3 using Pseudomarker (v 0.9) statistical framework. The aim of this study was to generate a double congenic strain to confirm chromosome 3 QTL and investigate the interaction between loci on the implicated chromosomes.

Methods
: A marker-assisted breeding strategy was used to generate the SP.WKYGla2a/3a double congenic strain (D2Rat13-D2Rat157, D3Mgh16-D3Wox28), using SHRSP as recipient and WKY as the donor strain. Haemodynamic measurements were carried out using radiotelemetry over a 5-week baseline period followed by 3 weeks of salt-loading (1%).

Results
: Radiotelemetry data for systolic blood pressure and pulse pressure are illustrated in figure

a + b respectively. Systolic blood pressure was significantly reduced in the SP.WKYGa2a/3a strain (n=7) compared to SHRSP (n=13) (p = 0.0001, F = 97.77, repeated measures ANOVA). Pulse pressure was also significantly reduced compared to SHRSP (p=0.0001, F=34.17) and achieved levels comparable to WKY (n=10). Pulse pressure diurnal variation observed in SHRSP during salt-loading was abolished in the double congenic strain (AUC; p=0.0001, F=13.56).

Conclusions
: Almost complete reversal of SHRSP hypertensive haemodynamic profiles has been achieved in the SP.WKYGla2a/3a double congenic strain. This strain will allow interrogation of complex gene-gene, gene-environment interactions contributing to salt-sensitive hypertension in the SHRSP.
Abstract 2746: Left Ventricular Diastolic Function Assessed By Tissue Doppler Echocardiography Is Impaired By β-blocker + Diuretic-based Therapy Compared With Calcium Antagonist + Ace Inhibitor-based Therapy: An ASCOT Substudy.
Authors: Tapp Robyn , Sharp Andrew , Stanton Alice , O’Brien Eoin , Chaturvedi Nish , Sever Peter , Poulter Neil , Hughes Alun , Thom Simon , Mayet Jamil
Published: July 2021

Background:
Different anti-hypertensive therapies may vary in their effect on left ventricular diastolic function. The Anglo-Scandinavian Cardiac Outcomes Trial (ASCOT) randomized patients to β-blocker (atenolol) + diuretic (bendroflumethiazide-K)-based therapy (BB/D) or calcium antagonist (amlodipine) + ACE inhibitor (perindopril)-based therapy (CA/ACEI). We compared left ventricular diastolic function in the two treatment groups.

Methods:
Echocardiography including Tissue Doppler Imaging was performed on 977 subjects at two centres participating in ASCOT (St Mary’s Hospital, London, UK & Beaumont Hospital, Dublin, Eire) to assess left ventricular diastolic function after 12 months of treatment. Data are means (SD).

Results:
Systolic blood pressure (SBP) was similar in both treatment groups (BB/D = 137(17), CA/ACEI = 136(14); p = 0.3), but heart rate was significantly lower in BB/D group (BB/D = 57(10), CA/ACEI = 73(12); p<0.001). Ejection fraction did not differ between groups (BB/D = 69.5 (11.3)%, CA/ACEI = 69.2 (12.2)%, p = 0.8), but early diastolic mitral annular velocity (E’), a measure of diastolic relaxation, was significantly lower in BB/D group (BB/D = 7.9(1.8), CA/ACEI = 8.8 (2.0); p <0.001). E/E’, a measure of left ventricular filling pressure, was also significantly higher in BB/D group (8.1 (2.4) vs. 7.8 (2.1), p=0.01). Differences in E’ or E/E’ remained highly significant (<0.001) after adjustment for covariates (age, sex, fasting plasma glucose, body mass index and cholesterol). Further adjustment for SBP and heart rate had no impact on differences in mean E’ (p<0.001), but differences in E/E’ were attenuated.

Conclusions:
BB/D based therapy is associated with impaired diastolic function compared with CA/ACEI therapy. Differences in the effect of anti-hypertensive therapy on diastolic function could influence the risk of heart failure and other cardiovascular events in hypertensive patients with preserved systolic function.
Abstract 387: Prolactin-Releasing Peptide, the Novel Endogenous Ligand of the Orphan Receptor GPR10, Regulates Cardiac Contractility
Authors: Kónyi Attila , Skoumal Réka , Kubin Anna-Maria , Horváth Iván G , Tóth Miklós , Papp Lajos , Ruskoaho Heikki , Szokodi István
Published: July 2021

The hypothalamic prolactin-releasing peptide (PrRP), which is the endogenous ligand of the orphan receptor GPR10, plays an important role in the regulation of the central stress response, sleep regulation and feeding behavior. Although specific binding sites have been found in the rat myocardium, the functional importance of PrRP in the regulation of cardiovascular system is still unknown. The objective of the present study was to characterize the direct cardiac effects of PrRP as well as the underlying signaling mechanisms. In the isolated perfused, paced rat heart preparation (male 7-week-old, Sprague-Dawley rats, n=138), intracoronary infusion of PrRP-31 (1–30 nmol/L) for 15 min induced a dose-dependent, slowly developing positive inotropic effect, with a maximal increase in developed tension at the dose of 10 nmol/L (13.6%±3.1, P< 0.001). Next we tested if various counter-regulatory mechanisms could modify the effect of PrRP. The phosphodiesterase inhibitor IBMX (10 μmol/L) failed to alter the inotropic response to PrRP (10.7±1.9%, P=N.S.) excluding the involvement of cAMP-dependent mechanisms. In contrast, the specific protein kinase C-alfa (PKC-alpha) inhibitor Ro32– 0432 (100 nmol/L) significantly increased the inotropic response to PrRP (21.6±3.4%, P<0.05) as well as the phosphorylation of phospholamban at Ser-16 (1.5±0.09 vs. 1.0±0.18; P<0.001) as measured by Western blotting. Moreover, the protein phosphatase (PP1/PP2A) inhibitor calyculin A (CyA) augmented the effect of PrRP on contractility (20.7 ±1.7%, P<0.001) similarly to PKC-alpha inhibition, whereas the PP2A inhibitor okadaic acid (10 nmol/L) had no effect (7.8±1.0 %, P=N.S.). Furthermore, long-term (120 min) administration of PrRP resulted in a greater increase in contractility (20.3±3.1 %) as compared to short-term infusion (15 min; P<0.05). Our results provide the first evidence for the functional significance of PrRP in the heart. The positive inotropic effect of PrRP is mediated via cAMP-independent mechanisms, which are suppressed by enhanced activity of PKC-alpha and PP1. We suggest that PrRP may play an important role in the long-term regulation of myocardial contractility.
Abstract 388: Postconditioning Beyond The Heart: Postconditioning The Ischemic Kidney Attenuates Renal Reperfusion Injury
Authors: Eldaif Shady M , Deneve Jeremiah , Wang Ning Ping , Mosunjac Mario , Jiang Rong , Granfeldt Asger , Zhao Zhi-Qing , Guyton Robert A , Vinten-Johansen Jakob
Published: July 2021

Objective
: Postconditioning (Poc), defined as brief cycles of arterial occlusion and reflow applied at the onset of reperfusion (R), has proven to reduce multiple consequences of myocardial ischemia-reperfusion injury (I/R). The protective effects of Poc in the kidney I/R are not known. Therefore, we tested the hypothesis that Poc attenuates renal I/R injury via adenosine receptor (AR) activation and protein kinase C (PKC) signaling.

Methods
: The in vivo single kidney rat model was used. Rats underwent right nephrectomy and were randomized to 5 groups.

A sham group (n=8) underwent the surgical and perfusion protocol without other interventions. In all remaining groups, the left renal artery is occluded for 45min and the left kidney was reperfused for 24 hours.

Control group (n=8) received no intervention at R;

Poc (n=8) underwent 4 cycles of 45 seconds R and 45 seconds of reocclusion at the onset of R.

PC + ARi (n=6): the AR inhibitor 8-SPT (10mg/kg) was administered i.v. 5 minutes before Poc;

Poc + PKCi: the PKC inhibitor, chelerytherine (5mg/kg), was administered i.v. 5 min before R.

After 24 hours, renal function was assessed by plasma blood urea nitrogen (BUN) and creatinine (Cr), and the kidneys were harvested; apoptotic cells were quantified by TUNEL stain and morphological injury by H&E staining.

Results:
Compared to sham, BUN and Cr were greater in control I/R group, which was significantly reduced in Poc (table

). Inhibition of AR or PKC stimulation reversed the reductions in BUN and Cr achieved by Poc. In addition, renal I/R increased the percentage of TUNEL positive cells in ten high powered fields vs Sham, which was reduced by Poc. Blockade of AR and PKC reversed the apoptosis reduction achieved by Poc.

Conclusion:
Postconditioning attenuates renal dysfunction and apoptosis induced by R injury and involves AR and PKC signaling. Poc suggests that R injury is triggered in early moments of reflow.
Abstract 2755: Insulin Resistance and Coronary Artery Calcification measured by Electron Beam Tomography
Authors: Lee Robert , Hajsadeghi Fereshteh , Ramirez Jessica , Sarlak Behnaz , gopal Ambarish , Ahmadi Naser , Budoff Matthew J
Published: July 2021

Background:
Elevation in the ratio of triglyceride to high-density lipoprotein cholesterol (TG/HDL-C) has been suggested as a marker of insulin resistance (IR), conferring an increased risk of atherosclerosis in these patients. The association between TG/HDL-C and coronary artery calcification (CAC) measured by computed tomography has yet to be established. The goal of this study was to examine the relationship between IR, as determined by TG/HDL-C ≥ 3.5, and significant CAC (absolute score ≥ 100).

Methods:
Fasting lipid levels, homocysteine, C reactive protein and lipoprotein (a) levels of 336 asymptomatic individuals, who also underwent electron beam tomography (EBT), were measured.

Results:
The mean age of participants was 55 ±10 years. 71.7% were male. 37.4% had hypertension, 52.5% had hypercholesterolemia, 12.4% had diabetes mellitus (DM) and 52.5% had family history of premature CHD. Individuals with IR had higher significant CAC (≥100) than those without IR (70% vs. 27%, P=0.0001). After adjustment for age, gender, hypertension, hypercholesterolemia and DM, multivariate regression analysis demonstrated that individuals with IR had more significant CAC (odds ratio 2.1, 95% CI=1.1–3.9, p=0.01). Further sub-analysis revealed that individuals with IR had significantly higher lipoprotein (a) (Lp(a)) than those without IR (odds ratio 1.31, 95% CI=1.09-.16, p=0.03). No significant differences in C-reactive protein (CRP) and homocysteine were found between the two groups.

Conclusion:
Insulin resistance, as measured by TG/HDL-C ≥ 3.5, was associated with a significantly higher incidence of accelerated atherosclerosis on EBT (absolute CAC score ≥ 100), independent of age, gender and conventional risk factors. IR was also significantly associated with elevated levels of Lp(a). Further studies regarding the clinical significance of insulin resistance and elevated CAC score, as well as its association with Lp(a), may be warranted.
Abstract 2764: The Advantages of using Multi-slice Spiral Computed Tomography to Evaluate Serious Coronary Complications in Adolescents after Kawasaki Disease
Authors: Kanamaru Hiroshi , Karasawa Kensuke , Ichikawa Rie , Abe Osamu , Miyashita Michio , Taniguchi Kazuo , Ayusawa Mamoru , Sumitomo Naokata , Okada Tomoo , Sato Yuichi , Harada Kensuke , Mugishima Hideo
Published: July 2021

Objectives
We identified novel multi-slice spiral computed tomography (MSCT) findings in adolescents after Kawasaki disease that could not be detected by coronary angiography (CAG).

Methods
We studied 18 patients who had suffered from serious coronary arterial lesions after Kawasaki disease (mean age: 21.7 years; range: 13 to 34 years). Seventeen patients had stenotic lesions, and all had coronary aneurysms. MSCT was performed using a Siemens SOMATOM Volume Zoom (4-detector row) or a Toshiba Aquillion 16 (16-detector row). The detection of coronary calcification, stenotic lesion, and intimal hypertrophy was applied to all coronary arteries in MSCT and compared to CAG.

Results
Of the 18 patients, there were 11 (61%) in whom novel findings were detected by MSCT. Coronary calcifications were found in 11 of the 18 patients (61%) by MSCT. Five patients had concentric calcified aneurysms, 4 had eccentric calcified aneurysms, and the other 2 had mixed calcified aneurysms. Coronary stenotic lesions were present in 6 of the 18 patients (33%) with calcified aneurysms. There were 2 patients who had intimal hypertrophy (11%). One patient had intimal hypertrophy along the left main trunk with a giant calcified aneurysm along the left anterior descending artery. Two patients had severe stenoses just distal to giant calcified aneurysms that were regarded as false positive findings, which were identified as mild stenoses by CAG.

Conclusions
MSCT offers advantages over CAG in the evaluation of calcified aneurysms and intimal hypertrophy, and has the potential to become a diagnostic modality for coronary intervention in adolescents after Kawasaki disease.
Abstract 394: Posttranslational Modification Of Klf5 Mediates Metabolic Dysfunction And Vascular Disease In Metabolic Syndrome
Authors: Oishi Yumiko , Manabe Ichiro , Tobe Kazuyuki , Kadowaki Takashi , Nagai Ryozo
Published: July 2021

We have previously shown that a zinc finger transcription factor, Krüppel-like factor 5 (KLF5), plays an important role in pathogenesis of cardiovascular diseases, such as atherosclerosis. KLF5 heterozygous knockout (
KLF5

+/
−

) mice exhibited much less neointima formation, cardiac hypertrophy and fibrosis. We also found that expression of KLF5 correlated with a higher incidence of restenosis following PCI and the SNP located within the
KLF5
promoter was associated with an increased risk of hypertension in man. Interestingly, KLF5 is also expressed in metabolic tissues such as adipose tissue, skeletal muscle, and pancreatic β-cells. Thus, we hypothesized that KLF5 might play a role in metabolic diseases. To test this,
KLF5

+/
−

mice were fed with high-fat diet. Although
KLF5

+/
−

mice ate more food than wild-type littermates, they were resistant to high-fat diet-induced obesity and protected from dyslipidemia, glucose intolerance and hepatic steatosis, indicating that
KLF5

+
/−

mice were less susceptible to metabolic syndrome. The systemic O
2
consumption and expression of genes involved in energy expenditure in skeletal muscle were increased in
KLF5

+
/−

mice, demonstrating enhanced energy expenditure, which partly explains the phenotype. Knocking down KLF5 by siRNA increased expression levels of UCP2/3 and CPT-1b in C2C12 myotubes, suggesting that KLF5 may inhibit energy expenditure-related genes. Chromatin immunoprecipitation and coimmunoprecipitation assays showed that KLF5 interacted with corepressors, such as SMRT and NCoR, and strongly inhibited the
UCP
and
CPT-1b
promoters. We found that this inhibitory activity of KLF5 depended on its SUMOylation. When KLF5 was deSUMOylated, it activated the promoters. These data demonstrate that KLF5 acts as a molecular switch for energy expenditure and the posttranslational modifications of KLF5 including SUMOylation turns on/off the switch function of KLF5. Given that KLF5 also controls tissue remodeling in response to external stress, KLF5 may mediate metabolic dysfunction and atherosclerosis in metabolic syndrome. Our findings also suggest that the posttranscriptional modification of KLF5 is an attractive novel therapeutic target.
Abstract 2840: An Impedance Threshold Device Improves 24 Hour Survival in a Spontaneously Breathing Pediatric Porcine Model of Hemorrhagic Shock
Authors: Metzger Anja , Marino Brad , Matsuura Tim , Alexander Carly , Herman Margot , McKnite Scott , Srinivasan Vijay , Nadkarni Vinay , Lurie Keith
Published: July 2021

Introduction: Traumatic injury and hypovolemic shock are leading causes of death in children worldwide. We previously demonstrated that augmentation of negative intrathoracic pressure generated by spontaneously breathing through an impedance threshold device (ITD) improves blood pressure and cardiac output in a pediatric porcine model of hemorrhagic shock. However, the optimal method to restore intravascular volume, prevent secondary organ damage, and prevent progression of reversible shock to irreversible circulatory collapse after severe blood loss in children is not known.

Hypothesis: Breathing through an ITD for 90 min prior to fluid resuscitation will safely increase short and long-term survival rates.

Methods: Seventeen spontaneously breathing female piglets (12.4 ± 0.1 kg), anesthetized with propofol, were subjected to a 40% bleed and randomized in a prospective, blinded manner to either a sham or active ITD (cracking pressure of -7 cmH2O, Advanced Circulatory Systems, Minneapolis, MN) for 90 min. Shed blood was then reinfused. Work of breathing (WOB), 90 minute and 24 hour survival were evaluated. Survival analysis was performed using the Wilcoxon Rank Sum Test, Fischer’s Exact Test, and Kaplan-Meier Methods.

Results: Baseline and post-bleed heart rate, blood pressure, lactate levels, and arterial blood gas parameters were similar between groups. Piglets treated with the active ITD had significantly improved survival compared to the piglets treated with the sham ITD at 90 min (8/9 vs. 3/8, p=0.04). At 24 hours, Kaplan-Meier curve analysis revealed improved survival with the active ITD (6/9 vs. 2/8, p=0.04). The 3 animals in the active ITD group that did not survive died at a median time of 280 minutes (82–580), and the 6 animals in the sham group that did not survive, died at a median time of 69 minutes (24 –101) after bleed (p=0.11). The WOB at 45 min (J/L) was 73% higher in the active ITD group than the sham group (1.18 ± 0.07 vs. 0.68 ± 0.07, p= 0.001). The piglets safely tolerated the active ITD therapy.

Conclusion: In this spontaneously breathing, anesthetized piglet model of hemorrhagic shock, treatment with an active ITD for 90 min without supplemental fluid resuscitation significantly improved short and long-term survival rates.
Abstract 2846: Parental Perception of Uncertainty and Stress following the Norwood Operation in Infants with Single Ventricle
Authors: Elixson E. Marsha , Staveski Sandra , Nieves Jo Ann , Strawn Jennifer , Smith Cathy , Uzark Karen
Published: July 2021

Caregivers of infants with complex single ventricle (SV) may experience significant stress related to uncertainty concerning their infant’s heart condition and care needs. To better understand the stress experienced by these families, we assessed parental uncertainty, its relationship to patient characteristics, and compared to parents of premature infants (premies). As part of a multicenter study of feeding practices, parents of 52 neonates with SV completed the Mishel Parental Perception of Uncertainty scale (PPUS) prior to hospital discharge following the Norwood operation. The PPUS contains 4 subscales: Ambiguity, Lack of Clarity, Lack of Information (info), and Unpredictability. Mean age at surgery was 5.3 days (range 1–18) and mean weight 3.2 kg (range 2.2–3.8). Median hospital length of stay (HLOS) was 24 days. Mean O
2
saturation at discharge was 83% (range 72–94%). Primary feeding method at discharge was oral in 19, tube in 13, and combination of oral+ tube in 20. Thirty six were discharged with a daily home surveillance (HS) program.

Results: With higher scores = higher uncertainty, PPUS scores were highest related to unpredictability (mean/SD = 3.13/0.70) and lowest related to lack of info (mean/SD = 1.65/0.51). Overall PPUS scores in parents of infants with SV were significantly lower than norms reported for parents of premies, especially related to lack of info, p<.01. PPUS scores were not significantly correlated with infant age (r=.036), O
2
saturation (r=.104), or HLOS (r=.117), Parents of infants with oral + tube feeding tend to have lower PPUS scores (mean 67.2) than infants fed by tube alone (mean 73.1). Mean PPUS scores from parents of infants discharged with daily HS (69.9) were not significantly different than parents without HS (71.4).

Conclusion: Parents of infants with SV experience stress especially related to the unpredictability of their infant’s symptoms and outcome. SV parents perceive less uncertainty, especially related to lack of info regarding their infant’s diagnosis and illness severity than parents of premies. Alternative feeding strategies and home monitoring, (including monitoring associated with this study), may assist parents in dealing with the uncertainty of their child’s illness following the Norwood operation.