bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 15081: Determinants of Improvement in Renal Function Among Patients With Chronic Kidney Disease Who Participated in Cardiac Rehabilitation
Authors: Arakawa Tetsuo , Kumasaka Reon , Nakanishi Michio , Nakao Kazuyasu , Fukui Shigefumi , Ohara Takahiro , Yanase Masanobu , Noguchi Teruo , Yasuda Satoshi , Ogawa Hisao , Goto Yoichi
Published: July 2021

Background:
The safety and efficacy of cardiac rehabilitation (CR) in patients with chronic kidney disease (CKD) have not been established. There are conflicting reports about the effects of exercise on renal function in CKD patients, and there have been no studies about the determinants of change in renal function. The aims of this study are 1) to clarify the effect of CR and 2) to investigate the determinants of change in renal function in cardiac patients with CKD.

Methods:
A total of 759 consecutive cardiac patients with CKD (estimated glomerular filtration rate (eGFR) <60 ml/min/1.73 m2) who participated in CR were studied. All patients underwent measurements of eGFR and peak oxygen uptake (PVO2) before and 3 months after CR. Patients were divided into quartiles based on their change in eGFR. We compared the characteristics of patients in the first quartile (improved eGFR group) and the fourth quartile (worsened eGFR group).

Results:
Overall, after 3-months CR program, eGFR (47.4 to 49.8 ml/min/1.73 m2, p<0.0001) and PVO2 (1108 to 1237 ml/min, p<0.0001) increased and BNP decreased (253 to 195pg/ml, p<0.0001) significantly. The improved eGFR patients (n=190, eGFR 48.4 to 62.3 ml/min/1.73m
2
) were younger (65.5 vs. 71.4 years, p<0.0001). They also had higher body mass index (BMI, 23.2 vs. 22.3 kg/m2, p<0.0001), higher LVEF (44% vs 39%, p<0.001), higher PVO2 (73.2% vs. 65.4%, p<0.0001), and lower BNP (206 pg/ml vs. 297 pg/ml, p<0.0001) than the worsened eGFR group (n=190, eGFR 48.4 to 41.6 ml/min/1.73 m2). A lower proportion of the improved eGFR group had heart failure (13% vs. 39%, p<0.001). There were similar levels of statistically significant improvement in PVO2 after CR in both groups. In the multiple regression analysis, younger age, higher BMI, higher baseline PVO2, lower baseline eGFR, and greater improvement in PVO2 after CR were independent determinants of eGFR improvement.

Conclusion:
In cardiac patients with CKD, CR improved exercise tolerance without worsening renal function. Greater improvement in PVO2 was associated with greater improvement in eGFR after CR, suggesting that CR has a protective effect on the kidney in these patients.
Abstract 15170: Persistent Microvascular Obstruction Leads to Localized Iron Deposition and Active Inflammation Within Chronic Myocardial Infarctions
Authors: Kali Avinash , Cokic Ivan , Yang Hsin-Jung , Tang Richard , Dharmakumar Rohan
Published: July 2021

Introduction:
The mechanism by which persistent microvascular obstruction (PMO) post myocardial infarction (MI) exerts adverse long-term effects is not well understood.

Hypothesis:
We hypothesized that PMO, with or without reperfusion hemorrhage, can resolve into iron deposition within chronic MI (CMI) territories, and is associated with prolonged inflammation and adverse LV remodeling.

Methods:
Canines subjected to reperfused (n=17) and non-reperfused (n=16) MI underwent Cardiovascular Magnetic Resonance (CMR) at 7 (acute) and 56 days (chronic) post-MI. Cine, T2*-weighted and Late Gadolinium Enhancement images were used to characterize LV remodeling (End-Diastolic Sphericity Index (EDSI)), iron and PMO respectively. Histological analysis was used to examine chronic inflammation.

Results:
In the reperfused group, 9 canines had PMO and hemorrhage with subsequent chronic iron deposition (PMO+/T2*+), while 4 canines had no PMO, hemorrhage, or chronic iron deposition (PMO-/T2*-). The remaining 4 canines had PMO without hemorrhage (PMO+/T2*-), but all subsequently had chronic iron deposition. In the non-reperfused group, 15 canines had PMO, and acute and subsequent chronic iron deposition (NR-PMO+/T2*+); 1 canine had no PMO, acute or chronic iron deposition (NR-PMO-/T2*-). In both groups, PMO volume was significantly associated with both acute and chronic iron volumes (p<0.001 all cases). In both groups, infarct and iron volumes measured in both acute and chronic phases were significant predictors of change in EDSI between acute and chronic phases (p<0.01 all cases). Histological sections of the harvested hearts post day 56 CMR showed extensive newly recruited macrophage, IL-1β, TNF-α and MMP-9 activities highly localized with iron in CMI regions (p<0.001 all cases).

Conclusions:
PMO, with or without reperfusion hemorrhage, can lead to iron deposition within CMIs, and is associated with active inflammation and adverse LV remodeling in canines.
Abstract 15173: Empowering Human Cardiac Progenitor Cell-mediated Repair of Injured Myocardium by Overexpressing P2Y14 Nucleotide Receptor
Authors: El-Sayed Farid , Nguyen Jonathan , Sussman Mark
Published: July 2021

Heart failure is a leading cause of death in the US due to the limited capability of adult mammalian heart to regenerate following injury. Autologous stem cell therapy holds promise for regeneration of injured myocardium after myocardial infarction. However, stem cells derived from diseased organs exhibit impaired proliferation and migration and increased susceptibility to cell death. Empowering stem cells from diverse origins, including cardiac progenitor cells (CPCs), with pro-survival genes has been attempted. Despite the well-established roles of purinergic signaling mediated by extracellular nucleotides in regulating diverse cellular responses in cardiovascular diseases, it has not been well-defined in CPCs. Our preliminary data show, for the first time, that the majority of P2 purinergic receptors are expressed in human CPCs (hCPCs) isolated from patients undergoing left ventricular assist device (LVAD) implantation surgery. The G protein-coupled UDP-sugar-sensing P2Y14 receptor (P2Y14R) has been shown to stimulate keratinocyte proliferation and migration, neutrophil and hematopoietic stem cell (HSC) chemotaxis in addition to increasing HSC resistance to stress-induced senescence. We aim to determine whether P2Y14R plays similar regenerative roles in cardiac tissue where the P2Y14R-mediated physiological responses haven’t been previously addressed. Our preliminary data show that the P2Y14R selective agonist UDP-Glucose enhances hCPC proliferation, migration and survival. Interestingly, hCPCs that exhibit relatively slower growth kinetics and enhanced senescence show a dramatic decrease in P2Y14R expression compared to fast-growing hCPCs consistent with our hypothesis that overexpressing P2Y14R participates in rejuvenating hCPCs and improving their growth capabilities. This hypothesis will be tested in vivo by determining whether P2Y14R overexpression in hCPCs improves their reparative potential for injured mouse myocardium. Mechanistically, we show for the first time that UDP-Glu induces downstream activation of YAP linking the extracellular nucleotides released during cardiac ischemia to extracellular matrix sensing and Hippo signaling that have been recently implicated in cardiac regeneration.
Abstract 15185: Risk Factors for Sudden Death in Chagas Cardiomyopathy
Authors: Peixoto Giselle L , Siqueira Sérgio , Nishioka Silvana , Pedrosa Anísio , Teixeira Ricardo , Costa Roberto , Martinelli Martino
Published: July 2021

Introduction:
Sudden death (SD) is an important cause of death in Chagas Cardiomyopathy patients. We aim to identify associated factors for its occurrence in Chagas Cardiomyopathy patients requiring pacemaker (PM).

Methods:
We prospectively evaluated 527patients included in the PACINCHAGAS Study - Risk Stratification in Pacemaker Patients with Chagas Cardiomyopathy, which primary objective is to create a risk score to predict death in this population.The patients are submitted to an extent questionnaire which included clinical (NYHA class, symptoms, comorbidities and medications) functional (electrocardiography, holter and echocardiography) and electronic variables (burden of pacing and arrhythmias).Patients withat least 6 months of follow-up were included in this analysis.

Results:
The cohort included 337 (63.9%) females, the mean age was 62.6±12.0 years and 64.3% were in NYHA class I. Indication for PM implantation was atrioventricular block, sick sinus syndrome, atrial fibrillation with slow ventricular response and unknown in 72.7%; 20.7%; 4.7% and 1.9%, respectively. The mean time of PM was 11.6±9.0years. During a mean follow-up of 1.8±0.6 years, 74 (14.0%) patients died; 25 deaths (33.8%) were due to heart failure, 23 (31.0%)weresudden (9.7%), 8(10.9%) were due to other cardiovascular causes, and 11 (14.8%) were due to non-cardiovascular causes. The cause of death could not be determined in seven patients (9.5%).Univariate analysis shows that patients with SD were younger (57.1 versus 62.8years, P=0.033), have higher duration of QRS (172.8 versus 155.8msec, P=0.013), lower ejection fraction (38.7% versus 48.7%, P=0.002), higher left ventricular diastolic diameter (60.0 versus 48.7mm, P=0.001), higher systolic arterial pulmonary pressure (41.8 versus 34.9mmHg, P=0.038) and higher rate of segmental wall-motion abnormality (57.9% versus 23.3%, P=0.002. Advanced functional class and non-sustained ventricular tachycardia were not associated to SD.

Conclusions:
We found that lower age, higher QRS duration and presence of echocardiographic abnormalities were associated to sudden death in PM users with Chagas Cardiomyopathy.
Abstract 15206: Sustained Beneficial Effects of Multi-Electrode Renal Sympathetic Denervation on Cardiac Adaptations in Resistant Hypertension: A 24-months Follow-Up Study
Authors: Dimitriadis Kyriakos , Tsioufis Costas , Kasiakogias Alexandros , Vasileiou Panayiotis , Papanikolaou Aggelos , Pylarinou Voula , Lau Elizabeth , Worthley Stephen G , Papademetriou Vasilios , Tousoulis Dimitrios
Published: July 2021

Introduction:
The favorable impact of renal sympathetic denervation (RDN) on cardiac parameters such as on left ventricular (LV) morphology, geometry and function has been shown up to 6 months after the procedure using diverse ablation systems.

Hypothesis:
Multi-electrode catheter-based renal sympathetic RDN may have favorable effects on LV structural and functional indices in patients with resistant hypertension after a follow-up of 24 months.

Methods:
Twenty patients with resistant hypertension [age: 57±10 years, 13 males, office blood pressure (BP): 182/97±19/18 mmHg under 4.5±0.6 drugs] who underwent RDN were followed-up for 24 months. A full transthoracic echocardiographic study was performed in all patients and LV mass was calculated using the Devereux formula and was indexed for body surface area and height.

Results:
Average office BP was reduced to 148±21/85±14 mmHg at 12 months and to 143±23/80±14 mmHg at 24 months (p<0.001 for all). In the RDN group, LV mass index was significantly reduced from 136±20.1 g/m
2
(56.5±8.7 g/m
2.7
) to 121±16.6 g/m
2
(50.6±6 g/m
2.7
) at 12 months and to 115.6±23.3 g/m
2
(48.8±9.3 g/m
2.7
) at 24 months (p<0.01 for all). RDN decreased mean interventricular septum thickness from 12.1±1.2 mm to 11.4±0.9 mm at 12 months and to 11.3±0.9 mm at 24 months (p<0.05 for all). After RDN, the number of patients with concentric LV hypertrophy (i.e. relative wall thickness >0.42 and LV mass >48 g/m
2.7
for male and >44 g/m
2.7
for female) decreased from 16 patients (80%) at baseline to 10 patients (50%) at 12 months, and to 7 patients (36.8%) at 24 months. Regarding diastolic function RDN caused an increase in mitral valve E'/A' ratio from 0.62±0.28 to 0.70±0.25 at 12 months and to 0.84±0.32 at 24 months (p<0.05 for all) and a decrease in the E/E' ratio from 14.8±6.1 to 11.8±3.7 at 12 months and to 9.7±4 at 24 months (p<0.05 for all).

Conclusions:
This the first study to show that multi-electrode RDN results in a significant and sustained improvement of diastolic function and attenuation of LV mass index in increased cardiovascular risk resistant hypertensive patients after a follow-up of 24 months. These results suggest long-term pleiotropic cardiovascular benefits of RDN therapy in the setting of resistant hypertension.
Abstract 15255: Statins Augment Circulating MicroRNA-499-5p Release With Muscle Contraction and Aerobic Exercise
Authors: Min Pil-Ki , Park Joseph , Isaacs Stephanie , Taylor Beth A , Thompson Paul D , Troyanos Chris , D’Hemecourt Pierre , Dyer Sophia , Chan Stephen Y , Baggish Aaron L
Published: July 2021

Background:
Statins exacerbate exercise-induced skeletal muscle injury. Muscle-specific microRNAs (myomiRs) increase in plasma after prolonged exercise, but the patterns of myomiRs release after statin-associated muscle injury have not been examined.

Objectives:
We examined the relationships among statin exposure, in vitro and in vivo muscle contraction, and candidate circulating myomiRs expression.

Methods:
We measured plasma levels of the myomiRs, circulating microRNA-1 (c-miR-1), c-miR-133a, c-miR-206 and c-miR-499-5p, from 28 statin-using and 28 non-statin using runners before (PRE), immediately after (FINISH), and 24 hours after a 42 km footrace (POST-24). We subsequently used contracting mouse C2C12 cultured myotubes with and without statin exposure to compare intracellular and extracellular expression of these molecules. Fold-changes of microRNAs are presented as median [interquartile range].

Results:
In marathoners, c-miR-1, c-miR-133a, and c-miR-206 increased at FINISH, returned to baseline at POST-24, and were unaffected by statin use. In contrast, c-miR-499-5p was unchanged at FINISH in both groups, but c-miR-499-5p increased in statin users at the POST-24 time point compared to PRE [2.9 (1.3, 8.6) vs. 1.0 fold change, p <0.001] and to non-statin using runners [2.9 (1.3, 8.6) vs. 1.4 (0.9, 3.2) fold change, p < 0.05]. In cultured C2C12 myotubes, intracellular levels of candidate myomiRs remained stable except for modest declines of miR-1 and miR-206 with isolated myotube contraction (carbachol exposure) or simultaneous statin and myotube contraction. Extracellular miR-1, 133a, and 206 increased with contraction regardless of statin use. In contrast, extracellular miR-499-5p was unaffected by either isolated statin exposure or isolated contraction but increased with contraction + statin [4.8 (1.9, 8.1) vs. 1.0 (0.7, 1.5) fold change, p < 0.05 vs. control].

Conclusions:
Statin-potentiated muscle injury during exercise is accompanied by augmented extracellular release of miR-499-5p. c-miR-499-5p may serve as a biomarker of statin-potentiated muscle damage.
Abstract 15314: Left Ventricular Dysfunction in Children and Adolescents With Arrhythmogenic Right Ventricular Cardiomyopathy
Authors: Chungsomprasong Paweena , Hamilton Robert , Luining Wietske , Yoo Shi-Joon , Fatah Meena , Manlhiot Cedric , Mccrindle Brian W , Grosse-Wortmann Lars
Published: July 2021

Background:
Involvement of the left ventricle (LV) is increasingly recognized in adults with arrhythmogenic right ventricular cardiomyopathy (ARVC) but it is unclear whether LV function is compromised in children with this condition. The aim of this study was examine myocardial contractility in pediatric patients with suspected ARVC.

Methods:
For this retrospective study, patients with a work-up for ARVC were classified into ‘no’, ‘possible’, ‘borderline’ or ‘definite’ ARVC according to the revised Task Force Criteria (rTFC). Ventricular size and function as well as LV myocardial strain and torsion were measured by cardiac magnetic resonance (CMR).

Results:
A total of 142 patients were enrolled, of whom 58 (41%) had no, 32 (23%) possible, 29 (20%) borderline and 23 (16%) definite ARVC. The groups were similar in age at CMR. With higher rTFC score, z scores (Z) of right ventricular (RV) ejection fraction (EF) were lower (p<0.001) while z-RV end diastolic volume (EDV) and z-LV EDV were larger (p=0.002 and 0.013, respectively). LV EF did not differ between rTFC categories. Global circumferential strain (GCS) of the LV was lower in patients in higher rTFC categories (p=0.018). Z-LVEDV correlated with z-RVEDV (r2 = 0.69, p<0.001) and z- LVEF correlated with z-RVEF (r2 = 0.55, p <0.001). Z-LVEF and z-RVEF correlated with LV GCS (r2 = 0.48, p<0.001 and r2 = 0.46, p<0.001, respectively) and torsion (r2 = 0.21, p=0.032 for both). Forty-two patients had a follow-up CMR, after a median interval of 2.6 years (0.4- 8.4). The rate of deterioration of LV or RV EF or EDV did not differ between rTFC categories. A more rapid increase of z-RVEDV was associated with a faster decline in z-RVEF (r2 = -0.383, p=0.004) and z-LVEF (r2 = -0.45, p=0.001). A decline of z-LVEF over time correlated with that of z-RVEF (r2 = 0.60, p<0.001) and z-LVEDV increase correlated with z-RVEDV increase (r2 = 0.84, p<0.001).

Conclusion:
LV myocardial dysfunction is present in young patients with suspected or confirmed ARVC. Quantification of myocardial mechanics with CMR may be a useful tool to detect early LV involvement in ARVC. Progressive LV dysfunction and enlargement appear to parallel those of the RV.
Abstract 15322: Pacinchagas-crt: A Cohort Study of Cardiac Resynchronization Therapy in Patients With Chronic Chagas Cardiomyopathy
Authors: Martinelli Martino , Peixoto Giselle L , Siqueira Sérgio , Santos Johnny , Martins Sérgio , Nishioka Silvana , Pedrosa Anísio , Teixeira Ricardo , Costa Roberto
Published: July 2021

Background:
Cardiac resynchronization therapy (CRT) is an established procedure for patients with heart failure (HF). However, trials evaluating its efficacy did not include patients with chronic Chagas cardiomyopathy (CCC), an important cause of HF in endemic countries. We aimed to assess the role of CRT in a cohort of patients with CCC.

Methods:
This was a retrospective study of consecutive CCC patients who underwent CRT between January 2005 and December 2012. We compared the outcomes of CCC patients who underwent CRT (CCC-CRT group) with those of ischemic and dilated cardiomyopathy patients who underwent CRT (CRT-control group) in the same period and with those of CCC patients with induced left bundle branch block (LBBB) who did not undergo CRT (CCC-control group). The primary endpoint was all-cause mortality and the secondary endpoint was echocardiographic changes, at least 24 months after CRT.

Results:
There were 115 patients in the CCC-CRT group, 311 in the CRT-control group, and 16 in the CCC-control group. The annual mortality rates were 25.4%, 10.9%, and 42.9%, respectively. Multivariate analysis adjusted for potential confounders showed that the CCC-CRT group had a two-fold (hazard ratio [HR] 2.11 [1.56-2.86], P<0.001) higher risk of death compared to the CRT-control group, and that the CCC-control group had an almost three-fold (HR 2.78 [1.09-7.01], P=0.032) higher risk of death compared to the CCC-CRT group.

Conclusions:
This cohort study showed that CRT has a favorable impact in patients with CCC, despite their worse prognosis compared to patients with other cardiomyopathies who undergo CRT.
Abstract 15333: Choosing Where to Live or Die: Regional Variation in Outcomes Following Out-of-hospital Cardiac Arrest (OHCA) in the United States
Authors: Albaeni Aiham , A. Beydoun May , M. Eid Shaker , Akinyele Bolanle , RaghavaKurup Lekshminarayan , A. Beydoun Hind , Chandra-Strobos Nisha
Published: July 2021

Background:
Regional Differences in health outcomes following OHCA has been poorly studied, and was the focus of this investigation.

Methods:
We used the 2002 to 2012 Nationwide Inpatient Sample database to identify adults ≥ 18 years old, with an ICD-9 code principal diagnosis of cardio respiratory arrest (427.5) or ventricular fibrillation (427.1). Trauma patients were excluded. In 4 predefined federal geographic regions: North East, Midwest, South and West, means and proportions of total hospital charges (adjusted to the 2012 consumer price index,) and mortality rate were calculated. Multiple linear and logistic regression models, were adjusted for patient demographics, hospital characteristics and Charlson Comorbidity Index. Trends in binary outcome were examined with YearхRegion interaction terms.

Results:
From 2002 to 2012, of 155,592 OHCA patients who survived to hospital admission , 26,007 (16.7%) were in the Northeast, 39,921 (25.7% ) in the Midwest, 56,263 (36.2%) in the South, and 33,401 (21.5% ) in the West. Total hospital charges (THC) rose significantly over the years across all regions of the United States ( P trend <0.0001), and were higher in the West Vs the North East (THC>$109,000/admission, AOR 1.85; 95% CI 1.53-2.24, p<0.0001), and not different in other regions. Compared to the Northeast, mortality was lower in the Midwest ( AOR 0.86, 95% CI 0.77-0.97 p=0.01), marginally lower in the South ( AOR 0.91, 95% CI 0.82-1.01 p=0.07), with no difference detected between the West and the Northeast ( AOR 1.02, 95% CI 0.90-1.16 P=0.78). Increased expenditure was not rewarded by an increase in survival, as trends in Mortality did not differ significantly between regions (YearхRegion effects P>0.05, P trend =0.29).

Conclusions:
Nationwide, there is a considerable variability in survival and charges associated with caring for the post arrest patient. Higher charges did not yield better outcomes. Further investigation is needed to optimize health care delivery.
Abstract 15386: Hospitalizations and Other Healthcare Resource Utilization Among Patients With Deep Vein Thrombosis Treated With Rivaroxaban versus Low-Molecular-Weight Heparin and Warfarin in the Outpatient Setting
Authors: Deitelzweig Steven , Laliberté François , Raut Monika , Germain Guillaume , Bookhart Brahim K , Olson William H , Schein Jeffrey , Lefebvre Patrick
Published: July 2021

Introduction:
Compared with low-molecular-weight heparin (LMWH) and warfarin, the oral anticoagulant rivaroxaban has advantages such as simplified care that may lead to less healthcare resource utilization (HRU).

Objective:
To compare HRU (hospitalization, emergency room [ER], and outpatient [OP] visit) among deep vein thrombosis (DVT) patients who received rivaroxaban or LMWH/warfarin in the outpatient setting.

Methods:
A retrospective matched-cohort analysis was conducted using the Truven Health Analytic MarketScan Claims database from 1/2011-12/2013. Adult patients with a primary diagnosis of DVT during an OP/ER visit after November 02, 2012, and who initiated treatment on the same day with rivaroxaban or LMWH/warfarin were identified. Patients were observed within 1, 2, 3, and 4 weeks after their DVT diagnosis. Mean number of all-cause and VTE (DVT or PE)-related hospitalizations and other HRU were evaluated using Lin’s method.

Results:
All of the 512 rivaroxaban patients were well-matched with LMWH/warfarin patients. Mean all-cause number of hospitalizations was significantly lower for rivaroxaban compared to LMWH/warfarin users within 1 week (0.012 vs 0.032; P=0.044) and 2 weeks (0.022 vs 0.048; P=0.040), and numerically lower within 3 weeks (0.038 vs 0.061; P=0.112) and 4 weeks (0.045 vs 0.078; P=0.058). Corresponding mean number of VTE-related hospitalizations was significantly lower for rivaroxaban within 1 week (0.008 vs 0.028; P=0.020) and 2 weeks (0.016 vs 0.042; P=0.020), numerically lower within 3 weeks (0.030 vs 0.052; P=0.074), and significantly lower within 4 weeks (0.034 vs 0.068; P=0.036). Corresponding all-cause OP visits were significantly lower for rivaroxaban users, while ER visits were similar between cohorts (Table 1).

Conclusion:
DVT patients treated with rivaroxaban following an OP/ER visits had significantly fewer hospitalizations and outpatient visits during the first weeks compared to matched LMWH/warfarin users.
Abstract 15433: Thrombin Activation of Platelet Protease-activated Receptor 4 Augments Atherosclerosis
Authors: Mann Adrien , Howatt Deborah A , Rateri Debra L , Daugherty Alan , Mackman Nigel , Owens A. Phillip
Published: July 2021

Objective:
Platelet activation has been shown to play a critical role in both formation and propagation of atherosclerosis. Protease-activated receptors (PARs) 1 and 4 mediate signaling by the coagulation protease thrombin. While PAR1 and 4 mediate thrombin activation on human platelets, mouse platelets contain PAR4 with PAR3 acting as a cofactor. Recent studies have demonstrated direct thrombin inhibitors (DTIs) reduced atherosclerosis in hypercholesterolemic mice. In this study, we examined the effect of PAR1 and 4 deficient on atherosclerosis using low-density lipoprotein receptor deficient (Ldlr
-/-
) mice.

Methods and Results:
Ldlr
-/-
mice that were PAR1
+/+
, PAR1
-/-
, PAR4
+/+
, or PAR4
-/-
(n = 5-20 each group) were fed a fat and cholesterol-enriched diet for 12 weeks. PAR4 deficiency attenuated aortic root (65% decrease; P = 0.001) and aortic arch (71% decrease; P = 0.001) atherosclerosis with no effects on total plasma cholesterol concentrations or lipoprotein distributions. These reductions were attributable to hematopoietic-derived PAR4 from analysis of bone marrow experiments. To determine if PAR4 mediated all effects of thrombin signaling, Ldlr
-/-
/PAR4
+/+
or Ldlr
-/-
/PAR4
-/-
mice were fed a fat and cholesterol-enriched diet, supplemented with placebo or the DTI dabigatran etexilate (30 g/kg diet) for 12 weeks. Dabigatran etexilate administration reduced atherosclerosis in PAR4
+/+
mice but not in PAR4
-/-
mice. PAR1 deficiency had no effect on atherosclerotic burden.

Conclusion:
We demonstrated whole body and hematopoietic PAR4 deficiency resulted in decreased aortic root and sinus atherosclerosis. PAR1 deficiency had no effects on atherosclerosis. Thrombin inhibition did not alter atherosclerosis in PAR4 deficient mice. Together, these results suggest that thrombin activation of PAR4 on platelets contributes to atherosclerosis.
Abstract 15441: MURC/Cavin-4 Requires the Coiled-coil Domain for Membrane Trafficking of Caveolin-3 in Cardiomyocytes
Authors: Nishi Masahiro , Ogata Takehiro , Naito Daisuke , Hamaoka Tetsuro , Nakanishi Naohiko , Miyagawa Kotaro , Maruyama Naoki , Kasahara Takeru , Ueyama Tomomi
Published: July 2021

[Background]
Muscle-restricted coiled-coil protein (MURC), also referred to as Cavin-4, is a member of the cavin family that is cooperated with caveolins in caveola formation and function. Cavins are cytoplasmic proteins that have coiled-coil domains and form heteromeric complexes, which are recruited to caveolae in cells expressing caveolins. Among caveolins, caveolin-3 (Cav3) is exclusively expressed in muscle cells, similar to MURC/Cavin-4. In the heart, Cav3 overexpression contributes to cardiac protection, while its deficiency leads to progressive cardiomyopathy. Mutations in the MURC/Cavin-4 gene have been identified in patients with dilated cardiomyopathy. MURC/Cavin-4 has the coiled-coil domain; however, its functional significance remains unknown.

[Methods and Results]
MURC/Cavin-4 was localized at the plasma membrane in H9c2 cells, while a MURC/Cavin-4 mutant lacking the coiled-coil domain (ΔCC) was primarily localized to the cytoplasm. ΔCC bound to Cav3 and impaired membrane localization of Cav3 in cardiomyocytes. In addition, although ΔCC did not influence Cav3 mRNA expression, it decreased the Cav3 protein level in cardiomyocytes. MURC/Cavin-4 and ΔCC similarly induced cardiomyocytes hypertrophy; however, ΔCC showed higher hypertrophy-related fetal gene expression, such as ANP, BNP, and skeletal α-actin (SkA) mRNA expression and the βMHC/αMHC ratio, than MURC/Cavin-4. ΔCC induced ERK activation in cardiomyocytes. Cardiac function assessed by echocardiography was significantly impaired in transgenic mice expressing ΔCC in the heart (ΔCC-Tg mice) compared with non-transgenic (NTg) mice (% FS; 24.6 ± 2.4 % in ΔCC-Tg mice vs. 48.8 ± 2.5 % in NTg mice, p<0.01), which was accompanied by cardiomyocyte hypertrophy, increased interstitial fibrosis, and the increase of lung weight-to-tibial-length ratio (LW/TL; 18.04 ± 2.41 in ΔCC-Tg mice vs. 7.51 ± 0.81 in NTg mice, p<0.01). ΔCC-Tg hearts showed reduction of the Cav3 protein level and the activation of ERK.

[Conclusions]
These results reveal that MURC/Cavin-4 requires its coiled-coil domain to target the plasma membrane and Cav3 trafficking to the plasma membrane of cardiomyocytes, and that MURC/Cavin-4 functions as a crucial caveolar component to regulate cardiac function.
Abstract 15465: Precision Medicine Approach to Resistant Hypertension: Genetic Markers of Resistant Hypertension Through a Genome-wide Association Study (GWAS) in the Secondary Prevention of Subcortical Strokes (SPS3)
Authors: El Rouby Nihal , McDonough Caitrin W , Gong Yan , McClure Leslie A , Mitchell Braxton D , Horenstein Richard B , Talbert Robert L , Takahashi Atsushi , Tanaka Toshihiro , Kubo Michiaki , Pepine Carl , Cooper-DeHoff Rhonda M , Benavente Oscar , Shuldiner Alan R , Johnson Julie A
Published: July 2021

Introduction:
Resistant hypertension (RHTN), a blood pressure (BP) ≥140/90 mm Hg despite ≥ 3 antihypertensive drugs or BP < 140/90 mm Hg using ≥ 4 drugs, is associated with increased incidence of adverse cardiovascular outcomes, especially stroke.

Hypothesis and objective:
We hypothesize common variants exist in the genes regulating BP response and may lead to RHTN in some patients.

Methods:
A discovery cohort of hypertensive participants were included as cases (as defined above) or controls (N=719; 263 whites, 322 Hispanics, and 134 African Americans) from SPS3-GENES. They were genotyped on the Illumina Omni 5 Exome chip. Multiple logistic regression analysis was conducted separately in each race using an additive genetic model, adjusting for predictors for RHTN, principle components for ancestry and BP target treatment arms. Results from the 3 racial groups were combined using meta-analysis with inverse-variance weighting, with the hypothesis that functional variants are consistent across races. The associations of seven SNPs that met the suggestive level of association (p <1 x10-5) in the SPS3 meta-analysis were tested for replication in 1,194 participants (657 whites, and 537 Hispanics) from the INternational VErapamil-SR trandolapril STudy GENEtic Substudy (INVEST-GENES). Bonferroni adjusted p was set at 0.007 to correct for multiple comparisons. Combined meta-analysis between INVEST and SPS3 was conducted for replicated SNPs or SNPs that had consistent association in the two cohorts with a nominal significance.

Results:
A missense SNP (rs3766160; Asp114Asn) in CELA2B was associated with increased risk of RHTN in SPS3 (Combined OR=1.8, p=6x10-6)). The same SNP replicated in INVEST (Combined OR=1.3, p=0.004; INVEST/SPS3 meta-p=4.5x10-7). An intronic SNP rs3789592 in strong linkage disequilibrium (r2=0.98) with a missense SNP (rs1049434; Asp490Glu) in SLC16A1 was associated with RHTN in SPS3 (Combined OR=2.0, p=7.6x10-7) and had a consistent association in INVEST (Combined OR=1.2, p=0.048; INVEST/SPS3 meta-p=7.6x10-7).

Conclusion:
Genetic loci in CELA2B, SLC16A1 were identified and confirmed for association in two cohorts. These associations, if further validated may help identify those patients at risk for RHTN.
Abstract 15466: Bioactive Contents and Cardiovascular Regenerative Potential of Extracellular Vesicles Derived From Induced Pluripotent Stem Cells
Authors: Adamiak Marta , Bobis-Wozowicz Sylwia , Karnas Elzbieta , Kedracka-Krok Sylwia , Sarna Michal , Cheng Guangming , Samanta Anweshan , Girgis Magdy , Madeja Zbigniew , Dawn Buddhadeb , Zuba-Surma Ewa
Published: July 2021

Introduction:
Extracellular vesicles (EVs) are tiny membrane-enclosed vesicles released by cells by membrane budding or exocytosis. The molecular profile of contents and regenerative potential of EVs derived from murine induced pluripotent stem cells (miPSCs) have not been investigated.

Hypothesis:
We hypothesized that miPSC-derived EVs carry bioactive substances, including mRNA and miRNA, which would influence the biology and fate of target cells.

Methods:
Murine iPSCs were generated using established protocols and EVs were isolated from culture supernatants by sequential centrifugation. Atomic force microscopy (AFM), flow cytometry, and real-time RT-PCR were used to characterize EV contents. Endothelial cells were exposed to miPSC-EVs in culture.

Results:
AFM and dynamic light scattering showed that miPSC-EVs are homogenous spherical vesicles smaller than 100 nm (Fig, A). High-sensitivity flow cytometry confirmed the presence of several iPSC- specific markers along with typical exosomal markers (CD9, CD63 and CD81) on miPSC-EVs. miPSC-EVs were enriched in mRNAs, miRNAs and proteins from donor iPSCs as shown by real-time RT-PCR and mass spectroscopy, respectively. Moreover, miPSC-EVs contained transcripts regulating pluripotency, self-renewal and differentiation, including Oct-4, Nanog, GATA-4 as well as miR290-295 cluster (Fig, B,C). Importantly, several miRNAs were found to be higher in EVs when compared with parental miPSCs (Fig, B,C). Endothelial cells treated with miPSC-EVs exhibited greater proliferative, metabolic and angiogenic activities, and were more resistant to apoptosis.

Conclusions:
Our data show, for the first time, that miPSC-derived EVs are natural nanocarriers capable of transferring bioactive contents to mature cells affecting target cell function as well as regenerative potential. We conclude that iPSC-EVs may represent safe therapeutic alternatives to whole cell-based therapy for cardiovascular repair.
Abstract 15477: Endothelial Cells Overexpressing Interleukin-8 Receptors are Renoprotective in Rats With Acute Kidney Injury
Authors: Hage Fadi G , Xing Dongqi , Giordano Samantha , Guo Yuanyuan , Oparil Suzanne , Chen Yiu-Fai , Sanders Paul
Published: July 2021

Introduction:
In ischemia-reperfusion acute kidney injury (AKI) interleukin-8 (IL8) attracts neutrophils to the site of injury. Neutrophils interact with the damaged endothelium triggering the pro-inflammatory response that prolongs the underperfused state of the kidney and exacerbates injury.

Hypothesis:
We tested the hypothesis that intravenous transfusion of rat aortic endothelial cells (ECs) transduced with IL8 receptors (IL8RA/RB-ECs) ameliorates renal dysfunction and promotes structural recovery of the kidney post AKI.

Methods and Results:
Male Sprague-Dawley rats were subjected to sham surgery or AKI by clamping the left renal artery for 45 min and removing the right kidney. At time of reperfusion, 1.5x10
6
IL8RA/RB-ECs, ECs with empty adenoviral vector (AdNull-ECs), or vehicle were infused in the femoral vein. At 24 hrs after AKI, serum creatinine increased ~ 10 fold in the vehicle-treated group and then decreased towards baseline. IL8RA/RB-ECs but not AdNull-ECs significantly blunted the rise in serum creatinine (Fig) and decreased the local expression in the kidney and the circulating levels of inflammatory mediators at 24 hrs after AKI. At 6 wks after AKI, vehicle-treated rats had significant albuminuria compared to sham controls and EC treatment decreased albuminuria by ~65% (Fig). Stained kidney sections at 6 wks after AKI showed that vehicle-treated rats had increased interstitial collagen and decreased capillary density compared to sham controls. IL-8RA/RB-ECs were more effective at reducing interstitial collagen staining than AdNull-ECs. IL8RA/RB-ECs but not AdNull-ECs increased capillary density compared to vehicle (Fig).

Conclusions:
Following ischemia-reperfusion AKI, ECs equipped with IL8 receptors are attracted to the site of injury in order to inhibit inflammation, accelerate tissue repair, and preserve renal function. Our innovative cell-based strategy holds promise for improving outcomes after AKI.
Abstract 15483: Functional Relevance of Rare GUCY1A3 Variants in Patients Affected by Premature Myocardial Infarction
Authors: Wobst Jana , Dang Tan A , Kessler Thorsten , von Ameln Simon , Tennstedt Stephanie , Hengstenberg Christian , Erdmann Jeanette , Schunkert Heribert
Published: July 2021

Introduction:
Myocardial infarction (MI) is the main complication of coronary artery disease (CAD). Recently, a locus tagging the GUCY1A3 gene has been shown to be genome-wide significantly associated with CAD. GUCY1A3 encodes the α1 subunit of the soluble guanylyl cyclase (sGC), a heterodimer composed of α1 and β1 subunits. Activated by nitric oxide (NO) the sGC produces cGMP. cGMP mediates various cellular functions including vasodilatation and inhibition of platelet aggregation. Besides this common variant, our group also identified rare variants in the coding sequence of GUCY1A3 associated with CAD/MI.

Aim:
We aimed to investigate the functional implication of rare variants found in CAD/MI patients regarding expression level, dimerization capability and enzymatic activity.

Methods and Results:
Employing whole-exome sequencing our group identified two rare GUCY1A3 variants in two extended families with a high prevalence of premature CAD/MI (Erdmann et al Nature 2013). Sequencing the respective exons in further 252 young MI patients led to the identification of seven additional rare variants.

Effects on protein level were investigated by Western blotting after overexpression in HEK cells. Except for one of the variants, all dimerized with β1 shown by co-immunoprecipitation. One of the α1 variants exhibited significantly decreased protein levels compared to wild type α1 while another showed significantly increased protein levels. The amounts of β1 subunits correlated with those of α1 in all cases. sGC enzymatic activity was assessed by measuring cGMP by radioimmunoassay after stimulating overexpressed HEK cells with NO. Three of the variants demonstrated significantly decreased cGMP production at every time point tested. cGMP levels only correlated in part with the observed protein levels.

Conclusion and Outlook:
We identified nine rare variants in the coding sequence of GUCY1A3 and demonstrated some of them leading to altered protein levels as well as diminished activity. As both mechanisms in the end influence the capacity of cGMP formation, this appears to be a possible mechanism for GUCY1A3 leading to atherosclerosis and MI. Future studies will focus on mRNA abundance and protein degradation to uncover the reason for altered protein levels.
Abstract 15501: True Bipolar Left Ventricular Pacing is Associated With Better Survival in Cardiac Resynchronization Therapy Patients
Authors: Kutyifa Valentina , Moss Arthur J , Stein Kenneth , Wang Paul J , Musat Dan , Jones Paul , Wehrenberg Scott
Published: July 2021

Introduction:
Prior studies suggested better outcomes in cardiac resynchronization therapy (CRT) patients with true bipolar left ventricular (LV) pacing compared to unipolar or extended bipolar LV pacing. However, we lack confirmatory data from larger patient cohorts.

Methods:
We reviewed de-identified device data from 65,620 HF patients with an RF-enabled CRT-D device followed on the LATITUDE system (LATITUDE® system, Boston Scientific, St. Paul, MN). Long-term survival was assessed by LV lead pacing polarity. Patients with LV bipolar leads paced between the LV tip and ring were identified as LV true bipolar pacing, while those with LV bipolar leads paced between the LV tip or LV ring to the RV coil were identified as LV extended bipolar pacing. Unipolar LV pacing was assessed as a separate sub-group. Kaplan-Meier survival analysis and multivariable Cox hazards regressions models were utilized to assess all-cause mortality by LV lead pacing polarity.

Results:
There were 24,033 patients (37%) with LV true bipolar pacing, 38,327 patients (58%) with extended bipolar LV pacing, and 3260 patients (5%) with LV unipolar pacing. LV true bipolar pacing was associated with a significantly higher likelihood of survival during follow-up compared to patients with LV unipolar pacing (log-rank p<0.001), that translated into a significant 28% reduction in all-cause mortality (HR 0.72, 95% CI: 0.65-0.80, p<0.001) after adjustment for age and gender (Figure). The survival benefit between LV true bipolar pacing and LV extended bipolar pacing was smaller, but nevertheless statistically significant (HR=0.91, 95% CI: 0.65-0.80; p<0.001).

Conclusion:
In this large patient cohort, true bipolar LV pacing was associated with better long-term survival in cardiac resynchronization therapy patients compared to LV unipolar or LV extended bipolar pacing. When feasible, programming true bipolar LV lead pacing polarity should be considered in cardiac resynchronization therapy patients.
Abstract 15566: Induced Pluripotent Stem Cell-Derived Cardiomyocytes Recapitulate Clinically Observed Refractoriness to Therapeutic β-Blockade in a Patient-Specific Model of Catecholaminergic Polymorphic Ventricular Tachycardia
Authors: Preininger Marcela K , Jha Rajneesh , Wu Qingling , Singh Monalisa , Maxwell Joshua T , Wang Bo , Fischbach Peter S , Dalal Aarti , Wagner Mary B , Xu Chunhui
Published: July 2021

Introduction:
Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an inherited arrhythmia syndrome characterized by diastolic store overload-induced Ca2+ waves during β-adrenergic receptor (β-AR) stimulation. Mysteriously, β-blockers are ineffective at abolishing stress-induced ventricular arrhythmias in ~25% of patients. Induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) generated from these CPVT patients offer an attractive system for investigating the phenomenon, but it remains unknown whether iPSC-CMs can recapitulate clinically observed patient-specific drug responses.

Hypothesis:
This study assessed the hypothesis that patient-specific refractoriness to β-blocker therapy can be observed in vitro using CPVT iPSC-CMs.

Methods:
We generated iPSC-CMs from a control individual and a CPVT patient insensitive to the widely prescribed β-blocker nadolol, but responsive to flecainide, and compared the efficacy of the two drugs in vitro in diminishing diastolic Ca2+ waves and restoring Ca2+ spark parameters during β-AR stimulation.

Results:
In CPVT hiPSC-CMs (n = 34), β-AR agonism elicited intense diastolic Ca2+ waves and potentiated unduly frequent, large, and prolonged Ca2+ sparks compared to control iPSC-CMs (n = 12). Pursuant to the patient’s in vivo responses, nadolol-treated CPVT iPSC-CMs (n = 27) demonstrated inadequate improvement of Ca2+ handling defects during β-AR stimulation relative to flecainide-treated CPVT iPSC-CMs (n = 25). Nadolol showed no significant effect on the frequency of diastolic Ca2+ waves, but reduced mean amplitude by 50% (p < 0.0001). In contrast, flecainide reduced both frequency and amplitude by 83% (p < 0.001) and 72% (p < 0.0001), respectively. During nadolol treatment, Ca2+ spark frequency, width, and duration remained significantly altered, while flecainide restored all Ca2+ spark parameters to baseline levels.

Conclusions:
Clinically observed recalcitrance to β-blocker therapy in individuals with CPVT can be modeled in vitro using patient-derived iPSC-CMs. Furthermore, the efficacy of other drugs such as flecainide can be comparatively evaluated, supporting the use of patient-specific iPSC-CMs as a clinically-relevant implement of precision medicine.
Abstract 15567: Increased Visceral Fat Volume is Associated With Aortic Inflammation and Cardiovascular Events
Authors: Takx Richard A , Figueroa Amparo L , MacNabb Megan H , Abdelbaky Amr , Lavender Zachary R , Kaplan Rebecca S , Grinspoon Steven K , Truong Quynh A , Hoffmann Udo , Tawakol Ahmed
Published: July 2021

Introduction:
While the relationship between obesity and cardiovascular disease (CVD) is well-established, mechanisms underlying this relationship are not well elucidated.

Hypothesis:
Our hypothesis is that visceral adipose tissue (VAT) volume, aortic inflammation and the risk of subsequent cardiovascular events are linked together.

Methods:
Individuals who underwent 18F-FDG PET/CT imaging were included. VAT volume, subcutaneous adipose tissue (SAT) volume and aortic FDG uptake were measured while blinded to clinical data. Cardiovascular events were adjudicated by independent cardiologists. Thereafter, the relationship between VAT volume and aortic FDG activity and cardiovascular events was evaluated using Cox proportional hazard models.

Results:
The final analysis included 415 patients with a median age of 55 (P25-P75: 45-65) years and a median BMI of 26.4 (P25- P75: 23.4-30.9) kg/m2. VAT and SAT volume were significantly higher in obese individuals. 32 subjects experienced cardiovascular event during a median follow-up of 4 years. Cox proportional hazard models showed that VAT volume was a associated with cardiovascular events (hazard ratio, HR (95% CI): 1.15 (1.06-1.25, p<0.001). This remained significant after correcting for age, BMI and aortic TBR (p<0.05). SAT was not predictive of cardiovascular events. VAT volume was associated with arterial inflammation (r=0.29, p<0.001, Figure 1). The combination of high aortic inflammation and high VAT volume was associated with significant worse survival (p<0.05).

Conclusions:
We observed that VAT volume is a predictor of subsequent cardiovascular events. Moreover, our results indicate a link between visceral adipose tissue volume and arterial inflammation, which may explain some of VAT's association with cardiovascular events.
Abstract 15570: Direct Evidence of Endo-Epicardial Dissociation of the Atrial Wall in Patients With Longstanding Persistent Atrial Fibrillation
Authors: de Groot Natasja , vd Does Lisette , Yaksh Ameeta , Knops Paul , Woestijne Pieter , Kik Charles , Bogers Ad , Allessie Maurits
Published: July 2021

Introduction:
Transition of paroxysmal to longstanding persistent atrial fibrillation (LsPAF) is associated with progressive longitudinal dissociation in conduction and a higher incidence of focal fibrillation waves. The aim of this study was to provide direct evidence that the substrate of LsPAF consists of an electrical double-layer of dissociated waves, and that focal fibrillation waves are caused by endo-epicardial breakthrough.

Hypothesis:
LsPAF in humans is caused by electrical dissociation of the endo- and epicardial layer.

Methods:
Intra-operative mapping of the endo- and epicardial right atrial wall was performed in 9 patients with induced (N=4), paroxysmal (N=1), persistent (N=2) or longstanding-persistent AF (N=2). A clamp of two rectangular electrode-arrays (128 electrodes; inter-electrode distance 2mm) was introduced through an incision in the right atrial appendage. Series of 10 seconds of AF were analyzed and the incidence of endo-epicardial dissociation (≥15ms) was determined for all 128 endo-epicardial recording sites.

Results:
In patients with LsPAF the averaged degree of endo-epicardial dissociation was highest (24.9% vs. 5.9%). Using strict criteria for breakthrough (presence of an opposite wave within 4mm and <15ms before the origin of the focal wave), the far majority (77%) of all focal fibrillation waves could be attributed to endo-epicardial excitation.

Conclusions:
During LsPAF considerable differences in activation of the right endo- and epicardial wall exist. Endo-epicardial fibrillation waves that are out of phase, may conduct transmurally and create breakthrough waves in the opposite layer. This may explain the high persistence of AF and the low succes rate of ablative therapies in patients with LsPAF.