Abstract 11202: A Biomarker of Stress and Self-Reported Stress Related to Caregiving Predict Poor Quality of Life in Caregivers of Patients With Heart Failure

Circulation, Volume 146, Issue Suppl_1, Page A11202-A11202, November 8, 2022. Introduction:Caregivers of patients with heart failure (HF) are at high risk of low quality of life due to stress-related to caregiving. Self-reported measures are commonly used to assess relatively long-term stress related to caregiving. Still, biological markers of stress, a short-term stress measure, are rarely used. There is limited knowledge on whether both can predict the quality of life in caregivers of patients with HF.Hypothesis:The stress biomarker (serum cortisol) and subjective distress related to caregiving (Caregiver Burden Inventory) predict the quality of life in caregivers of patients with HF.Methods:In this cross-sectional study, Taiwanese caregivers of patients with HF completed surveys including stress-related caregiving and quality of life measured by the Caregiving Burden Inventory and the Short Form-36, respectively. A blood sample for serum cortisol was collected between 9 and 12 AM. Independent t-test and multivariable linear regression analysis were conducted adjusting for age, gender, education, marital status, relationship with care-recipient and depressive symptoms (Patient Health Questionnaire).Results:Of the 113 caregivers (mean age 54.5 years, 70.8% female, 78% married/cohabitated), 59% cared for patients with NYHA class III/V. Single caregivers had higher serum cortisol levels than married caregivers (11.4 vs. 8.5, p =.002). Males had a significantly higher serum cortisol level than females (10.7 vs. 8.5, p =.010), but males reported a lower caregiver burden than females (1.3 vs. 1.6, p =.049). Both serum cortisol (β =-.36, P=.012) and caregiver burden (β = -.29, P= .018) were significant predictors of physical well-being. Serum cortisol (β= -.28, p=.026) and caregiver burden (β =-.25, p =.027) also significantly predicted mental well-being.Conclusions:Although stress levels are different by caregivers’ characteristics, both cortisol level and self-report caregiver burden have similar predictability of quality of life in caregivers of patients with HF. Reducing stress and caregiver burden is necessary to improve the quality of life in this population.

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Ottobre 2022

Abstract 11029: Bioenergetic Independent Stress Signaling in the Heart Due to Mitochondrial Protein Import Stress

Circulation, Volume 146, Issue Suppl_1, Page A11029-A11029, November 8, 2022. Mitochondrial diseases are some of the most common genetically inherited disorders, yet the prognosis for affected patients has not drastically improved in recent years. Most therapies are supportive as the underlying biochemical derangements in these diseases are incompletely understood. Mitochondrial functions rely on the import of nuclear-encoded proteins, and it has recently been appreciated that defective import of mitochondrial proteins can result in the cytosolic accumulation of these preproteins. The accumulation of these preproteins results in cellular toxicity independently of any changes to the mitochondrial bioenergetic function, raising the possibility that mitochondrial protein import stress may be a yet uncharacterized pathway that links mitochondrial dysfunction with pathology. Here, we model this cytosolic mitochondrial precursor overaccumulation stress (mPOS) in mice through overexpression of the inner mitochondrial membrane protein Adenine Nucleotide Translocase 1 (ANT1). The goal of this study is to determine whether ANT1 can induce mPOS and tissue remodeling prior to the onset of cardiac bioenergetic defects. Using isolated cardiac mitochondria from these mice, we detected a moderate decrease in the levels of Complex I, II ,and IV. By measuring oxygen consumption in these mitochondria from 2-month-old animals, we found only a mild reduction in complex II based state 3 and 4 respirations. No change in complex I-based state 3 and 4 respirations was observed. Using RNAseq and western blot analysis, we find the robust activation of the integrated stress response (ISR). Transcriptomic data further demonstrates a strong upregulation of transcripts involved with 1-carbon metabolism, the amino acid starvation response, and proteolysis. Using echocardiographic evaluation of heart function on anesthetized mice at 6 months old, we find no significant alteration in systolic function. Together these data support the idea that mPOS may be a potent trigger of the ISR in a bioenergetics-independent manner. Whether activation of the ISR can alter cardiac function later in life is being evaluated.

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Ottobre 2022

Abstract 10484: Carotid Plaque Score Adds Discriminatory Benefit to the Stress Echo for Major Adverse Cardiovascular Events in Low-Intermediate Risk Cardiac Patients

Circulation, Volume 146, Issue Suppl_1, Page A10484-A10484, November 8, 2022. Introduction:Carotid plaque is recommended for cardiac risk stratification for intermediate risk patients but has not been integrated into cardiology community clinics to help refine testing and reduce risk for major adverse cardiovascular events (MACE). The purpose was to determine the clinical usefulness of carotid plaque score (PS) to guide management of low-intermediate risk patients.Methods:Patients 40-75 years who received a carotid ultrasound were followed up to 10 years for MACE (cardiovascular death, myocardial infarction, stroke). Low-intermediate risk participants (n = 9,114) with no known cardiovascular disease were included. Administrative data holdings housed at IC/ES were used for event follow-up. Kaplan-Meier curves and Cox proportional hazard ratios determined relative risk. Combining plaque score (Rotterdam method, plaque presence within carotid segments, PS 0 to 6) with stress echo (SE) was assessed in a subset of participants (n = 624).Results:The optimum threshold for PS = 2 for 1-year MACE (AUC = 0.738). The population rate of MACE over 10 years was 4%. In participants referred for SE, PS of

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Ottobre 2022

Abstract 14139: Differential Benefit of Non-Invasive Cardiac Stress Testing by HEART Score Risk Stratification

Circulation, Volume 146, Issue Suppl_1, Page A14139-A14139, November 8, 2022. Introduction:AHA guidelines recommend non-invasive cardiac testing (NIT) within 72 hours after an emergency department (ED) evaluation for suspected acute coronary syndrome (ACS), after acute myocardial infarction (AMI) has been excluded. However, the effectiveness of this strategy to reduce the risk of future AMI or death, in low-risk patients is contested.Hypothesis:We hypothesized that in patients with low risk based on history, electrocardiogram, age, risk factors and troponin (HEART) based scoring, early NIT may not be beneficial compared to higher risk.Methods:We compared the effectiveness of early NIT vs. no early testing, in a retrospective cohort of adult (age ≥18) members of the Kaiser Permanente Southern California health system from 05/2016-12/2020. We included all adults presenting at EDs with suspected ACS and who had data to compute HEART score. We stratified the cohort into low risk (score 0-3); intermediate risk (score 4-6) and high-risk (score ≥7) based on HEART score. Within each group, confounder adjusted instrumental variables models were used to evaluate the marginal effect of early NIT, and the number needed to treat (NNT) was calculated as the inverse of the absolute composite risk reduction in death/AMI within 30 days of ED discharge.Results:The cohort included 174,936 patients [61% Low risk (mean age 53; female 58%; early NIT 5%), 36% intermediate risk (mean age 71; female 72%; early NIT 18%), and 3% high risk (mean age 74, female 45%; early NIT 23%)]. The risk reduction in 30-day death/AMI due to early NIT increased progressively through the intermediate-risk (NNT = 59) and high-risk groups (NNT = 24) (Table 1). Risk reduction in the low-risk group was not statistically significant.Conclusions:HEART score based high risk patients may benefit the most from early NIT. However, the majority of the suspected ACS cohort was classified as low risk and the benefit of early NIT on 30-day death/AMI was uncertain in this low-risk group.

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Ottobre 2022

Abstract 10706: Transnitrosation From the NO-Receptor Soluble Guanylyl Cyclase to Oxidized Thioredoxin-1 Has a Potential Cardiovascular Protective Effect Against Oxidative Stress

Circulation, Volume 146, Issue Suppl_1, Page A10706-A10706, November 8, 2022. Soluble guanylyl cyclase (GC1) is an α/β heterodimer producing cGMP when stimulated by nitric oxide (NO). The NO-GC1-cGMP pathway is essential for cardiovascular homeostasis. Oxidative stress is known to disrupt the NO-GC1-cGMP pathway via oxidation of GC1 cysteines, which makes it unresponsive to NO stimulation. Under these conditions, GC1-α subunit “moonlights” by increasing cellular S-nitrosation via specific transfer of its nitrosothiols to cysteines of other proteins (transnitrosation). One of the SNO-targets identified by Mass Spectrometry (MS) was the oxidized form of Thioredoxin1 (oTrx1), which is unidirectionally transnitrosated by GC1 with αC610 as a SNO-donor and C73 of Trx1 as the SNO-recipient. Because oTrx1 itself drives transnitrosation, we sought and MS-identified SNO-proteins targeted by both GC1 and Trx1, suggesting a SNO-GC1→oTrx1→targets cascade. We investigated the (patho)physiological relevance of GC1-dependent transnitrosation activity by creating a knock-in (KI) mice with replacement of αC610 to a serine (αC610S). Biotin switch assays confirm that, under oxidative stress (Angiotensin II (AngII) treatment), global and Trx1 levels of S-nitrosation (SNO) were drastically reduced in lungs and hearts of KI mice compared to WT but the NO-stimulated GC1 activity was similar between WT and KI. Importantly, telemetry recordings indicated that 2 weeks of AngII treatment led to a more severe increase in BP and a more prolonged QTc in KI mice. The AngII-induced rise in MBP was 27.6 ± 2.5 mmHg in KI vs 21.6 ± 1.2mmHg in WT, while AngII-increase in QTc, reflecting delayed repolarization, was 12.53 ± 2.30ms in KI vs. 8.713 ± 2.72ms for the WT. The elevated BP with AngII treatment correlated with higher increase in cardiac hypertrophy, oxidation (measured by DHE staining) and fibrosis (picric acid staining) in KI mice. The AngII-induced increase in a) hypertrophy in KI was 0.63 ± 0.07 vs. 0.24 ± 0.08 mg/g in WT, b) cardiac oxidation was 0.19 ± 0.07 in KI and negligible in WT, and c) fibrosis was 1.75 (A.U) in KI vs. 1.31 in WT. These more severe cardiovascular dysfunctions in KI mice in response to AngII suggest that transnitrosation by GC1, potentially using oTrx1 as a nitrosothiol relay, is a mechanism of protection against oxidative stress.

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Ottobre 2022

Abstract 110: Threshold Adjusted Vagus Nerve Stimulation After Asphyxial Cardiac Arrest Results In Reduction Of Endoplasmic Reticulum Stress And Apoptosis

Circulation, Volume 146, Issue Suppl_1, Page A110-A110, November 8, 2022. Background:Vagus nerve stimulation (VNS) has been shown to improve survival and neurological outcomes after cardiac arrest (CA) and resuscitation by improving mitochondrial function, increasing cerebral blood flow, and reducing inflammation. However, the therapeutic cellular and subcellular mechanisms of VNS are not clearly understood in CA injury. Endoplasmic reticulum (ER) stress after cardiac arrest also contributes to cell death and is an underexplored area.Objective:The aim of this study was to investigate the protective effects of customized threshold-adjusted VNS (tVNS) in a rat model of CA and resuscitation in reducing ER stress and cell apoptosis.Methods and Results:Sprague-Dawley rats underwent 12 min asphyxial-CA followed by resuscitation. Rats were assigned to either post-resuscitation tVNS for 2 h or no-tVNS (control). tVNS was applied by electrode placement in the left cervical vagus nerve immediately after resuscitation. The tVNS was determined by a 15-20% reduction from the immediate baseline heart rate as the effective and physiological threshold for each animal. This enabled customized parameters for individual animals. At 2 h post-ROSC, rats were perfused with normal saline, and the whole brain was removed. The whole brain was then processed for protein expression by western blotting. We also prepared sham rats that did not receive CA or tVNS. For measuring ER stress we evaluated the expression of p-IRE1α protein and for apoptosis, we measured p-BAD protein. We observed a significantly higher protein expression of p-IRE1α in whole brain tissue after CA in control groups in comparison to the sham (p

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Ottobre 2022

Abstract 10720: Early Growth Trajectory is Associated With Post-Traumatic Stress in Parents of Infants With Congenital Heart Disease

Circulation, Volume 146, Issue Suppl_1, Page A10720-A10720, November 8, 2022. Background:Parents of infants with congenital heart disease (CHD) have described substantial stress over infant growth. Poor growth trajectory (GT) during early infancy may be a source of traumatic stress. The purpose of this study was to determine if differences exist in parent posttraumatic stress (PTS) between parents of infants with healthy versus poor GTs from hospital discharge to 4 months post discharge.Methods:This secondary analysis of a previously reported RCT (REACH telehealth trial NCT01941667) included parents of infants with CHD with stress measures at discharge and study end (n=136). Posttraumatic Diagnostic Scale was used to measure PTS. Weights were converted to weight for age Z scores (WAZ) using World Health Organization standards. WAZ-GT classes were identified using latent class growth modeling. We used multivariate logistic regression modeling to examine associations between WAZ-GT and parental PTS over the study period, adjusting for covariates.RESULTSOne-quarter of parents (n=37, 28%) demonstrated at least moderate PTS symptom severity at discharge and one-third at study end (n=40, 31%). We identified four distinct classes of infant WAZ-GT (Figure). Among the identified GTs, two were considered healthy growth patterns: “stable around WAZ=0” (n=51, 37.5%) and “maintaining WAZ > 0” (n=12, 8.8%). Therefore, these two patterns were collapsed to serve as one reference group for the analysis. Two additional WAZ-GT classes were identified that reflected poor growth: “partially-recovered” (n=44, 32.4%) and “never-recovered” (n=29, 21.3%). Parents of infants in the “never recovered” GT were at greater risk (OR=4.58; CI=1.54-13.64) for experiencing at least moderate PTS symptom severity at end of study as well as over time from discharge to end of study (OR=3.91; CI=1.60-9.86).CONCLUSIONResults offer new insights that parents of infants with poor GT are at increased risk for persistent PTS and may need additional screening and intervention.

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Ottobre 2022

Abstract 14078: Exercise Pulmonary Impedance and Coupling Stress Test, and MRI-Based Regional Strain Analysis: Identifying Afterload-Sensitive Phenotypes in PH-HFpEF

Circulation, Volume 146, Issue Suppl_1, Page A14078-A14078, November 8, 2022. Objectives:In pulmonary hypertension associated with HFpEF (PH-HFpEF), identifying mechanisms of right ventricular: pulmonary arterial (RV:PA) uncoupling can be leveraged for sub-phenotyping and targeted therapies. In this study, we aim to distinguish mechanisms of RV:PA uncoupling in PH-HFpEF due to high RV afterload (afterload-sensitive; AS) and impaired left ventricular-interventricular septal contributions to RV function (ventricular interdependence; VI).Methods:Subjects (n=13) with early-stage PH (per echo) and NYHA II-III dyspnea were prospectively enrolled. Exclusion criteria: advanced disease with NYHA IV, LVEF

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Ottobre 2022

Abstract 13635: Blunted Vascular Endothelial Function in Black Females: Examining the Impact of Psychosocial Stress Exposure versus Internalization and Coping

Circulation, Volume 146, Issue Suppl_1, Page A13635-A13635, November 8, 2022. Introduction:Among females in the United States, Black females suffer from the highest rates of hypertension, coronary artery disease, and total cardiovascular disease (CVD) mortality. Vascular endothelial dysfunction precedes overt CVD and predicts CVD risk and has been reported in this population, but this is not always a consistent finding. Although psychosocial stress from numerous sources likely contributes to this disparity, the precise pathways and mechanisms remain incompletely understood. A growing literature suggests that internalization and coping may be more important than exposure to stressors alone. Therefore, we examined the relationship between endothelial function (brachial artery flow-mediated dilation, FMD) and psychosocial stress exposure (adverse childhood experiences, ACEs; past week discrimination, PWD) versus internalization/coping (John Henryism Active Coping Scale, JHAC12; Giscombe Superwoman Schema Questionnaire, G-SWS-Q). We hypothesized that 1) FMD would be blunted in Black relative to White females and 2) among Black females, internalization and maladaptive coping would exhibit a stronger negative relationship with FMD than exposure to stressful experiences alone.Methods:Twelve Black (21 ± 3 yr) and 8 White (25 ± 6 yr) healthy females underwent standard FMD testing. Black participants completed the ACEs, PWD, JHAC12, and G-SWS-Q inventories. Higher scores indicated greater stressor exposure or endorsement of the internalization/coping constructs.Results:Brachial artery FMD was lower in Black relative to White females (4.93 ± 3.10 vs 8.58 ± 1.62%;p< .01). Neither ACEs (r= -.10,p= .75) nor PWD (r= -.24,p= .45) were associated with FMD. JHAC12 scores were (r= -.61,p= .02) and SWS scores tended to be (r= -.39,p= .11) negatively associated with FMD. Among the SWS subscales, SWS-Resistance to Being Vulnerable (r= -.51,p= .04) and SWS-Intense Motivation to Succeed (r= -.54,p= .04) were negatively associated with FMD.Conclusion:These preliminary data indicate that 1) brachial artery endothelial function is blunted in young Black females and 2) reduced vascular function in Black females may be due more to internalization and maladaptive coping than exposure to stressful experiences alone.

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Ottobre 2022

Abstract 13684: Comparison Between Men and Women With Severe Obesity for Risk of Adverse Outcomes of Myocardial Ischemia: An Exercise Stress Echocardiographic Study

Circulation, Volume 146, Issue Suppl_1, Page A13684-A13684, November 8, 2022. Background:Obesity and sex have a complex relationship with myocardial ischemia. We explored the association of sex and severe obesity with adverse cardiovascular outcomes in patients with ischemic exercise stress echocardiography (EXE).Methods:We retrospectively studied 142 patients with ischemic ExE [Age: 65±11 years, 70(49%) women, EF: 57±8%, body mass index (BMI): 28±6 kg/m2]. Severe obesity (BMI >35 kg/m2) occured in 48 (34%) patients. Patients were stratified based on obesity and sex (4 groups, women, and men with and without severe obesity), followed for median of 1.5 years, and compared for clinical, exercise variables and occurrence of composite outcomes (death, acute coronary syndrome, cardiac hospitalization and repeat ischemia testing).Results:In our study, 28(20%) women and 20(14%) men had severe obesity, and 42(29%) women and 52(37%) men had no severe obesity. Groups were not different for age, risk factors, exercise characteristics, and resting LV function. Outcomes occurred in 85(60%) patients and were more prevalent in women with severe obesity compared to women without or men with or without severe obesity [21(75%), 17(40%), 11(55%), and 35(67%), p=0.014]. Sex and severe obesity did not predict outcomes in isolation [HR: 1.13 (95%CI:0.74 to 1.73), 1.48 (95%CI:0.95 to 2.3), respectively, figure 1A, B]. Survival analysis showed that women without severe obesity were at lowest risk, men were at similarly elevated risk irrespective of severe obesity, and women with severe obesity were at highest risk for composite outcomes [p=0.037, figure 1C, HR: 2.5 (95% CI: 1.3 to 4.8)]. After adjusting for clinical, exercise, and echocardiographic variables, women with severe obesity remained at high-risk [HR: 2.2, (95% CI: 1.06 to 4.36)].Conclusion:In patients with ischemic ExE, women with severe obesity are at higher risk for adverse cardiac outcomes. Future studies are needed to understand the pathophysiologic mechanisms underlying this association.

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Ottobre 2022

Abstract 14955: The Biological Bases of Psychosocial Stress-Associated Cardiovascular Disease: Investigating the Cardioprotective Properties of Central Arginine-Vasopressin

Circulation, Volume 146, Issue Suppl_1, Page A14955-A14955, November 8, 2022. Psychosocial stressors (e.g., anxiety, personality traits, social isolation) are risk factors for cardiovascular events and heart disease. However, there is a lack of knowledge regarding the biological mechanisms that underlie this risk-outcome relationship. To address this knowledge gap, our team uses two non-traditional animal models, the Syrian hamster (Mesocricetus auratus) and gray short-tailed opossum (Monodelphis domestica). We previously reported that social isolation-induced aggression, a type of psychosocial stress experience, leads to increased neural activation in the ventral tegmental area (VTA) of the midbrain. The VTA contains tyrosine hydroxylase (TH)-producing (putative dopamine, DA) neurons and is innervated by vasopressin (AVP) fibers. DA and AVP play a role in social behavior, and we investigated whether these two systems interact when an individual experiences psychosocial stress-induced aggression. Here we report that social interactions increased Fos, the protein product of the immediate early genec-fosthat serves as a marker of neuronal activation, in non-TH cells in an area of the VTA called the interfascicular nucleus (IF) of male subjects. Previous social experience increased the number of TH-positive cells in the IF but had no effect on the number of AVP-ir fibers. Conversely, levels of aggressive and social dominance behaviors were positively correlated with the number of AVP-ir fibers in the IF, whereas there was no relationship between these behaviors and the number of TH-positive cells. In socially naïve males, AVP microinjected into the VTA inhibited the duration of aggressive behavior. We are currently investigating the impact of our psychosocial stress paradigms on myocardial injury in both males and females. Our results suggest a complex interaction between AVP and DA systems in the brain in psychosocial stress responses. Our long-term goal is to build on these preliminary findings to determine whether AVP in the VTA may reduce psychosocial stress-induced myocardial injury, a first step in exploring heart-brain interactions that may link psychosocial stress with negative cardiovascular disease outcomes.

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Ottobre 2022

Abstract 14230: Comparing Stress Echocardiography Parameters of Transgender Women With Their Cisgender Counterparts: The Mayo Clinic Women’s Heart Clinic

Circulation, Volume 146, Issue Suppl_1, Page A14230-A14230, November 8, 2022. Introduction:Stress echocardiography (SE) is a common functional imaging modality used for the detection of symptomatic coronary artery disease (CAD). Currently, the interpretation of SE relies on sex-based comparators for reporting parameters, including exercise time and functional aerobic capacity. These parameters are based on the cisgender male and female populations but have not been studied among transgender (TG) patients. Thus, we sought to characterize the SE parameters among a group of TG women.Methods:We designed a case-control study of TG women who underwent a SE at the Mayo Clinic. Each TG patient was age-matched with 2 cis-males and 2 cis-females. Demographics, medical history, and SE data were extracted. Conditional logistic regression analysis was performed to compare the TG cohort with each cisgender cohort separately.Results:Among the 43 TG females (age 57.7±9 years, 94.9% white), the prevalence of CAD was less than in cis-males (p=0.013) but similar to cis-females. For SE parameters, TG females had higher resting heart rates than cis-males (median [Q1, Q3]: 80 [71,93] vs 70 [64, 77]; p=0.002). Double product (24816 [21156, 27864] vs 26864 [22444, 30660]; p=0.016), exercise time (7.3 minutes [6,9] vs 8.5 [7.2, 9.5]; p=0.041), and metabolic equivalents (8.2 [7, 10] vs 9.5 [8.2, 10.5]; p=0.018), were all lower in TG females than cis-males. Exercise ejection fraction was higher in the transgender cohort than in cis-females (70 [70, 75] vs 70 [65, 70]; p=0.007). There was no difference in functional aerobic capacity or in the rest or stress wall motion score indices among the groups. Finally, there was no difference in the prevalence of positive electrocardiogram or SE studies.Conclusion:In conclusion, we report for the first time SE profiles for TG females which display an overall distinct phenotype compared to cis-males and cis-females. Larger prospective studies are warranted to further define these parameters for the TG population.

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Ottobre 2022

Abstract 13918: Combined ECG Precordial Voltage and Troponin-T in Stress Cardiomyopathy versus Anterior STEMI

Circulation, Volume 146, Issue Suppl_1, Page A13918-A13918, November 8, 2022. Introduction:Stress cardiomyopathy (SC) and anterior ST elevation myocardial infarction (AMI) share similar clinical and echocardiographic features on initial presentation, complicating their differentiation. Previously, subtle differences in 12-lead ECG between the two have been reported.Hypothesis:We propose that higher precordial R-wave amplitude on ECG and lower biomarkers values can serve as reliable predictors of SC during initial triage.Methods:Among patients admitted to a single center from 2015-2019 undergoing left heart catheterization (LHC) for suspected AMI, 76 patients with either LHC-proven SC or AMI (38 each) were included. All patients had transthoracic echocardiography (TTE) performed within 24 hours of LHC. Patients were excluded when TTE quality was poor. Left ventricular ejection fraction (LVEF) and speckle-tracking global longitudinal strain (GLS) were calculated from transthoracic apical views. Non-parametric variables were analyzed using Wilcoxon rank sum test. Sensitivity and specificity analyses were performed using ROC curves.Results:LVEF (33+9% vs 33+8%) and GLS (-7.5+2.8% vs -7.9+3.3%) were similar in both groups. R-wave amplitude in ECG leads V1-V2 was higher in SC compared to AMI (V1: 0.96 vs 0.54 mV, p = 0.035; V2: 1.46 vs 0.75 mV, p = 0.037). At index admission, peak pro-BNP was higher (22198 vs 3098, p = 0.002) and peak Troponin-T (1.43 vs 236, p

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Ottobre 2022

Abstract 9764: Simultaneous Assessment of Coronary Flow Reserve and Left Ventricular Strain During Vasodilator Stress Measured by 13N-ammonia Positron Emission Tomography/Magnetic Resonance Imaging

Circulation, Volume 146, Issue Suppl_1, Page A9764-A9764, November 8, 2022. Introduction:Hybrid positron emission tomography (PET)/magnetic resonance imaging (MRI) is able to yield important information regarding molecular and functional imaging in a one-stop examination. The aim of this study was to investigate the relationship between coronary flow reserve (CFR) and left ventricular longitudinal strain (LVLS) using simultaneous acquisitions on hybrid13N-ammonia PET/MRI.Methods:Thirty-eight patients with suspected coronary artery disease (CAD) who underwent13N-ammonia PET/MRI were enrolled. Vasodilator stress was induced by intravenous injection of adenosine. CFR was calculated from dynamic acquisition of13N-ammonia PET. LVLS was evaluated by feature-tracked MRI. Myocardial flow reserve (MFR) and LVLS values were based on a 17-segment model and three coronary territories, left anterior descending artery (LAD), left circumflex artery (LCx), and right coronary artery (RCA).Results:We analyzed 577 myocardial segments in the left ventricle. LVLS under vasodilator stress was significantly increased compared with LVLS at rest in myocardial segments with MFR ≥2.0 (P

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Ottobre 2022

Abstract 15536: Surface Lin28a Expression Consistent With Cellular Stress Parallels Indicators Of Senescence

Circulation, Volume 146, Issue Suppl_1, Page A15536-A15536, November 8, 2022. Aims:Declining cellular functional capacity resulting from stress or aging is a primary contributor to impairment of myocardial performance. Molecular pathway regulation of biological processes in cardiac interstitial cells (CICs) is pivotal in stress and aging responses. Altered localization of the RNA binding protein Lin28A has been reported in response to environmental stress, but the role of Lin28A in response to stress in CICs has not been explored. Surface Lin28A redistribution is indicative of oxidative stress response in CIC associated with aging and senescence.Methods and Results:Localization of Lin28A was assessed by multiple experimental analyses and treatment conditions and correlated to oxidative stress, senescence, and ploidy in adult murine CICs. Surface Lin28A expression is present on 5% of fresh CICs and maintained through passage 2, increasing to 21% in hyperoxic conditions but lowered to 14% in physiologic normoxia. Surface Lin28A is coincident with elevated senescence marker p16 and beta-galactosidase (β-gal) expression in CICs expanded in hyperoxia, and also increases with polyploidization and binucleation of CICs regardless of oxygen culture. Transcriptional profiling of CICs using single cell RNASeq reveals upregulation of pathways associated with oxidative stress in CICs exhibiting surface Lin28A. Induction of surface Lin28A by oxidative stress is blunted by treatment of cells with the antioxidant Trolox in a dose-dependent manner, with 300uM Trolox exposure maintaining characteristics of freshly isolated CICs possessing low expression of surface Lin28A and β-gal with predominantly diploid content.Conclusion and Clinical Perspective:Surface Lin28A is identified as novel surface marker of oxidative stress conditions that cause DNA damage and cellular senescence. Accumulation of surface Lin28A was inhibited by antioxidant treatment with lowered indices of cellular stress and senescence, revealing the potential of surface Lin28A as a diagnostic stress marker. Therapeutic strategies targeted toward surface Lin28 expression set the stage for next generation senolytics to remove stressed or senescent cells and promote recovery from tissue injury or aging.

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Ottobre 2022

Abstract 14065: Functional and Structural Alterations in Stress-Related Neural Networks Implicated in Atherosclerosis

Circulation, Volume 146, Issue Suppl_1, Page A14065-A14065, November 8, 2022. Introduction:While a link between chronic stress and cardiovascular disease (CVD) is well established, the neurocircuit alterations underlying this association remain unclear. We leveraged advanced multimodal imaging to gain insights into neurocircuit alterations that associate with atherosclerosis.Methods:Individuals with posttraumatic stress disorder (PTSD), trauma-exposed controls without PTSD (TC), and healthy controls (HC) were prospectively enrolled. Participants underwent whole-body18F-fluorodeoxyglucose positron emission tomography/magnetic resonance (FDG-PET/MR) imaging. Stress-related neural network activity (SNNA) was assessed on PET as amygdala metabolic activity relative to regulatory (ventromedial prefrontal cortex [vmPFC]) activity. The structural integrity of the uncinate fasciculus, the major white matter tract connecting the amygdala to vmPFC, was assessed using diffusion tensor imaging (DTI). Atherosclerotic burden was assessed on MR as vessel normalized wall index and standard deviation (SD) of vessel wall thickness.Results:Of 91 participants (24 PTSD, 42 TC, 24 HC), 57% were female, and the median age was 37 years. Compared to controls, individuals with PTSD had higher SNNA (Fig 1A) and lower uncinate fasciculus integrity (Fig 1B). SNNA and uncinate fasciculus integrity were negatively correlated (r = – 0.30, p=0.008). Those with PTSD had higher ascending aorta normalized wall indices (p=0.018, adjusted for Framingham risk score). Notably, the SD of carotid wall thickness correlated positively with SNNA and negatively with uncinate fasciculus integrity (Fig 1C & D).Conclusion:These findings suggest that increases in the amygdala relative to vmPFC metabolic activity or disruptions of their structural interconnections may potentiate atherosclerosis. Interventions targeting this stress-related neural network may reduce adverse brain-heart interactions and related cardiovascular disease burden.

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Ottobre 2022