bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 15666: Effectiveness of Sharpsense™ Algorithms in Reducing Pause and Bradycardia Detection: Real-world Performance Before and After the Software Upgrade in Confirm Rx™ Insertable Cardiac Monitor
Authors: Gopinathannair Rakesh , Lakkireddy Dhanunjaya , Piorkowski Christopher , Afzal Muhammad , Murtaza Ghulam , Qu Fujian , Dawoud Fady , Davis Kevin , Ryu Kyungmoo , Fischer Avi , Ip John
Published: May 2021

Background:
Recent enhancements have been introduced to the Abbott Confirm Rx™ insertable cardiac monitor (ICM) arrhythmia detection algorithms (SharpSense™). This study aims to characterize the real-world performance of SharpSense™ algorithms, in the upgraded ICM devices by comparing device detected pause and bradycardia (brady) episodes before and after the SharpSense™ upgrade.

Methods:
Confirm Rx™ devices with at least 90 days monitoring each before and after SharpSense™ upgrade were included in the study. Brady and pause episodes were extracted from Merlin.net™ patient care network for evaluation and adjudicated by expert adjudicators.

Results:
A total of 197 devices were included in the analysis. Devices were implanted for syncope (35%), AF management (33%), and other indications, including cryptogenic stroke and palpitations (32%). The SharpSense™ upgrade significantly reduced the total number of detected episodes by 92% (pause: 93%, brady: 87%) and the rate of transmitted episodes by 73.6% from 50.3 to 13.3 (pause: 34.9 to 6.0, brady: 7.8 to 1.5) episodes per patient-week (p < 0.001). SharpSense™ reduced false positive episodes by 82.8% and 91.5% for pause and brady, respectively. The percentage of devices with at least one false positive episode was reduced from 52% to 35% for pause and from 39% for 20% for brady. The number of devices with false positive rate greater than 1 episode per week was reduced from 39% to 20% for pause and from 23% to 8% for brady.

Conclusion:
SharpSense™ upgrade resulted in substantial reduction of pause and bradycardia episode detections, false positive detections, and frequency of transmitted episodes for clinic review.
Abstract 15680: Validation of Remote Measurement of the Qtc Intervals Using an Apple Watch
Authors: Spaccarotella Carmen , migliarino serena , mongiardo annalisa , Sabatino Jolanda , Santarpia Giuseppe , Curcio Antonio , De Rosa Salvatore , Indolfi Ciro
Published: May 2021

Introduction:
In many circumstances, especially in the Covid-19 period, it could be necessary to measure the QT interval repeatedly even daily.

Hypothesis:
The aim of the study was to evaluate the feasibility of remote measuring LI-LII and V2 leads with using a commercially available Apple Watch Series 4.

Methods:
The accuracy of the QTc calculation with the smartwatch compared to the standard ECG was tested using di!erent formulae. One hundred patients admitted to our CCU were studied. LI-LII and V2 tracings were obtained immediately after the recording of the standard 12-lead ECG. The LI was recorded with the smartwatch on the left wrist and the right index finger on the crown; LII was obtained with the watch on the left lower abdomen and the right index finger on the crown; V2 lead was recorded with a smartwatch in the fourth intercostal space left parasternal with the right index finger on the crown. All recorded 30” ECGs were digitally stored using the health application of an iPhone Series 10 in the pdf format. The advantage of saving the ECG in pdf format is that it can be sent also via e-mail.

Results:
There was an agreement between the QTLI, QT-LII, QT-V2 and QT mean intervals of smartphone electrocardiography tracings and standard electrocardiography using Spearman’s correlation coefficient of 0.881; 0.885; 0.801; 0.911 respectively [p<0.001]. The reliability of the mean QTc measurements was tested with Bland-Altman analysis using Bazett’s, Friedericia’s, and Framingham’s formulas between standard ECG and smartwatch(Figure).

Conclusions:
These data demonstrated the feasibility to measure the QTc in LI, LII and V2 leads with a smartwatch with results comparable to that performed with the standard ECG. These data could have an important clinical impact both for the widespread di!usion of smartwatches and for the monitoring of drug-induced QT interval prolongation, especially in the Covid-19 era.
Abstract 15688: Computational Fluid Dynamics Assessment of Exercise in Patients With Successfully Repaired Coarctation of the Aorta
Authors: Mandell Jason G , Aslan Seda , Loke Yue-hin , Mass Paige N , Cleveland Vincent , Hibino Narutoshi , Krieger Axel , Olivieri Laura J
Published: May 2021

Introduction:
Patients with coarctation of the aorta (CoA) have decreased exercise capacity even after successful repair with no anatomic obstruction. Our previous work demonstrated a robust negative correlation of aorta size mismatch, defined by ascending (AAo) to descending aorta (DAo) diameter ratio (D
AAo
/D
DAo
), and exercise capacity (VO2 max), suggesting geometry alters arch resistance. This study aims to identify the hemodynamic impact of aorta size mismatch with simulations of rest and exercise using computational fluid dynamics (CFD).

Methods:
An IRB-approved retrospective chart review identified patients with CoA repair who had a cardiac MRI and exercise stress test within 6 months. Each aorta was segmented and scaled to a body surface area of 1 m
2
. CFD was used to simulate rest (3 L/min/m
2
) and exercise (9 L/min/m
2
). Outlet resistance was tuned to match patient-specific DAo flow split derived from in vivo MRI and assumed unchanged for exercise. Power loss was calculated between AAo and DAo and correlated with D
AAo
/D
DAo
.

Results:
The patients (ages 12-41 years, mean 26.8±8.6), had a VO2 max ranging from 47 to 126% predicted (mean 92±20%). Power loss had a significant negative correlation with D
AAo
/D
DAo
at rest (p=0.001) and exercise (p<0.01). The ratio of power loss in exercise to rest positively correlated with D
AAo
/D
DAo
(p<0.05) (Figure).

Conclusions:
The relationship of power loss with aorta size mismatch is largely driven by altered flow distribution dependent on AAo and DAo size. There is a disproportionate increase in power loss with exercise compared to rest with a larger aorta size mismatch. This suggests arch geometry independently impacts power loss in exercise which is captured by the measurement of aorta size mismatch and can be a target for optimizing aortic arch repair.

Figure:
Ratio of power loss in exercise to rest correlates with D
AAo
/D
DAo
. Example aortic arches are shown with low power loss (green) and high power loss (red) with corresponding VO2.
Abstract 15694: Atrial Tachycardia Masquerading as Sinus Tachycardia - Electrophysiological Characteristics and Ablation Outcomes
Authors: Gopinathannair Rakesh , Akella Krishna , Murtaza Ghulam , Di Biase Luigi , Natale Andrea , Lakkireddy Dhanunjaya , Vijayaraman Pugazhendhi
Published: May 2021

Background:
Focal atrial tachycardia (AT) is typically distinguished by P wave morphology and autonomic response. AT arising close to the sinus node can be easily misdiagnosed as Inappropriate sinus tachycardia (IST).

Objective:
This multicenter study sought to describe the electrophysiological (EP) features and ablation outcomes of perisinus node atrial tachycardia (PNAT).

Methods:
Baseline as well as procedural characteristics and outcome data of 7 patients with PNAT are described.

Results:
Mean age of the cohort was 38±17 years (100% female). Time from symptom onset to diagnosis was12.2± 9 months with an average of 1.7 prior hospitalizations. Mean baseline HR was127.8 bpm and all patients carried a diagnosis of IST. Baseline ECG in all patients was identical to sinus tachycardia, with exception of taller P waves in lead II in 5 patients and deeper negative component of P wave in V1. At EP study, mean AT cycle length was 420 msec and significant acceleration was seen with isoproterenol, mimicking IST. Activation mapping was done using Ensite
TM
Balloon Array (5), Precision
TM
(1) and Carto
TM
(1). Site of origin was slightly anterolateral to sinus node in 3 and anterior, inferior and medial to sinus node in 4 (Figure). AT was successfully ablated in all patients without any phrenic injury or sinus node dysfunction. Over 2.9 years of follow-up, only 1 patient had recurrence that was successfully re-ablated.

Conclusion:
PNAT has similar ECG and EP characteristics and is often misdiagnosed as IST. A high index of suspicion is needed for diagnosis. Evaluation of P wave morphology during tachycardia and careful activation mapping can enable successful ablation with excellent long-term outcomes.
Abstract 15702: Chronic Use of Electronic or Tobacco Cigarettes Alters Circulating Polyunsaturated Fatty Acids, Oxidation Status and Cardiovascular Risk in Healthy Young Adults
Authors: Gupta Rajat , Lin Yan , Luna Karla , Logue Anjali , Yoon Alexander , Haptonstall Kacey , Moheimani Roya , Choroomi Yasmine , Nguyen Kevin , Tran Elizabeth , Zhu Yifang , Faull Kym , Gornbein Jeffrey , Middlekauff Holly , Araujo Jesus A
Published: May 2021

Introduction:
Electronic cigarettes (EC) have recently gained unprecedented popularity with over 5 million users in the United States. However, it is not known whether chronic EC use induces cardiovascular health effects in healthy young adults.

Hypothesis:
We hypothesized that chronic EC use ≥1 year affects lipid peroxidation and/or antioxidant defense in the circulating blood, as compared to chronic tobacco cigarette (TC) smokers.

Methods:
We enrolled EC-users (n=32), TC-smokers (n=29) and non-users (n=45) with mean ages of 28.3, 27.8 and 27.4 years, respectively. Plasma concentrations of polyunsaturated fatty acids and oxidized metabolites were assessed by liquid chromatography coupled to ion trap mass spectrometry. Total antioxidant capacity (TAC), heme oxygenase-1 (HO-1) and functional activity of paraoxonase1 (PON1) and arylesterase were determined by colorimetric and enzymatic assays in the plasma. Multivariable analysis was performed using classification models aimed at segregating subjects based on biomarker profiles.

Results:
As shown in table 1, EC-users and TC-smokers exhibited significant alterations in oxidized linoleic acid (LA) metabolites (9- and 13-hydroxyoctadecadienoic acid (HODE)), arachidonic acid (AA), LA, TAC and HO-1. Multivariable analysis identified a set of 5 biomarkers (13-HODE, LA, 9-HODE, 12-hydroxyeicosatetraenoic acid (HETE), and AA) that discriminated EC-users from TC-smokers and non-users with an overall accuracy of 73.4%.

Conclusions:
Chronic use of EC induces both common (i.e. reduced 9- and 13-HODEs, and increased TAC) as well as differential effects (i.e. altered concentrations of AA and LA) to those induced by TC, along with intermediate plasma HO-1 concentrations, suggesting that EC, likewise TC smoke, could impact cardiovascular risk.
Abstract 15722: Proton Pump Inhibitors and Risk of Myocardial Infarction: A Systematic Review and Meta-analysis
Authors: Mishuk Ahmed Ullah , Fahim Shahariar Mohammed , Hansen Richard , Chen Li , Gaillard Philippe , Westrick Salisa , Qian Jingjing
Published: May 2021

Introduction:
Proton Pump Inhibitors (PPIs) are generally considered safe, but recent evidence suggests otherwise.

Objective:
This systematic review and meta-analysis assessed the association between PPIs and the risk of myocardial infarction (MI), using both clinical trials and observational studies.

Methods:
A systematic search was performed in December 2019 to retrieve all potential studies using PubMed, PsycInfo, International Pharmaceutical Abstracts, Web of Science, and Clinicaltrials.gov. This search initially identified any published studies describing any adverse event (AE) or outcomes related to PPI. Records were included in this study if 1) studies were published in English, 2) study design was clinical trials or observational studies, 3) PPI use was the exposure or treatment, and 4) study outcome was the incidence of MI. Two researchers independently reviewed all identified records, performed full article review, extracted data into structured evidence table, and conducted quality assessment using Newcastle-Ottawa Scale and Quality Assessment Tool for Quantitative Studies. Meta-analysis was performed using the RStudio software to assess the risk of MI with PPI use.

Results:
A total of 4,507 abstracts meeting the inclusion criteria were identified, and 20 full articles were included in this study, among which 10 were cohort, 3 were case-control, 3 were RCT post-hoc analysis, and 4 were RCT studies. The pooled Odds Ratio (OR)=1.40 with 95% CI=1.20-1.63 for all studies indicated the presence of an association between PPI use and increased risk of MI compared to PPI non-users. Meta-analysis found a similar association between PPI use and increased risk of MI in observational studies (OR=1.40; 95% CI=1.20, 1.64) but no association (OR=0.90; 95% CI=0.47, 1.73) in RCT-studies. Heterogeneity was high (I
2
> 75%) for all analyses except for RCTs (I
2
=0%).

Conclusion:
Although our meta-analysis identified the association between PPI use and increased risk of MI, results from RCTs did not agree with observational studies. Due to the mixed findings by study designs and high variation of heterogeneity among studies, the pharmacovigilance system should evaluate different levels of evidence to support decision making in safety of drug products.
Abstract 15728: Machine Learning Helps Predict Short and Intermediate-term Risk for All Cause Mortality in Patients Undergoing Percutaneous Coronary Intervention
Authors: Agasthi Pradyumna , Ashraf Hasan , Chao Chieh-Ju , Wang Panwen , Allam Mohamed , Pujari Sai Harika , Fortuin F D , Eleid Mackram F , Yang Eric , Beohar Nirat , mookadam farouk , Holmes David R , Arsanjani Reza
Published: May 2021

Background:
Identifying patients at a high risk of mortality post percutaneous coronary intervention (PCI) is of vital clinical importance. We investigated the utility of machine learning algorithms to predict short and intermediate-term risk of all-cause mortality in patients undergoing PCI.

Methods:
Patient-level demographics, clinical, electrocardiographic ,echocardiographic and angiographic data from January 2006 to December 2017 were extracted from the Mayo Clinic CathPCI registry and clinical records. For patients with multiple PCI events, data collected at the time of the index PCI was used for analysis. Patients who underwent bailout coronary artery bypass graft surgery (CABG) prior to discharge were excluded. 306 variables were incorporated into random forest machine learning model (RF) to predict all-cause mortality at 6 months and 1 year after PCI. Ten-fold cross-validation repeated five times was used to optimize the hyperparameters and estimate its external performance. The National Cardiovascular Data Registry (NCDR) based logistic regression model was used for comparison. The area under receiver operator characteristic curves (AUC) was calculated to assess the ability of the models to predict all-cause mortality.

Results:
A total of 17356 unique patients were included for the final analysis after excluding 165 patients who underwent CABG surgery during the index hospitalization. The mean age was 66.9 ± 12.5 years;71% were male. Indications for PCI were ST-elevation myocardial infarction (9.4%), non-ST elevation myocardial infarction (12.9%), unstable angina (17.7%), and stable angina (52.8%) in the cohort. In-hospital, 6-month & 1 year mortality rates were 1.9%,4.2% & 5.8% respectively. The RF model was superior to the NCDR model in predicting inhospital, 6-month, 1 year mortality (p<0.0001) (
Figure 1
).

Conclusion:
Machine learning is superior to NCDR model in predicting short and intermediate risk of all-cause mortality post PCI.
Abstract 15729: Effect of Metformin on Outcomes of Catheter Ablation for Atrial Fibrillation
Authors: Deshmukh Amrish , Oral Elif , Ghannam Michael , Liang Jackson , Saeed Mohammed , Cunnane Ryan , Ghanbari Hamid , Latchamsetty Rakesh , Crawford Thomas , Bogun Frank , Jongnarangsin Krit , Pelosi Frank , Chugh Aman , Morady Fred , Oral Hakan
Published: May 2021

Background:
Diabetes mellitus (DM) and glycemic control are risk factors for atrial fibrillation (AF). Metformin may have antifibrillatory properties by altering atrial metabolism. It is unknown whether metformin has favorable effects on the outcomes of catheter ablation (CA) for AF.

Objective:
To determine whether metformin use is associated with maintenance of sinus rhythm after CA for AF.

Methods and Results:
A 1
st
CA was performed in 271 consecutive patients with DM and AF (age: 65±9 years, women: 34 %; and paroxysmal AF: 50%). A total of 182 (67%) patients were treated with metformin and 79/182 were also receiving other antidiabetics or insulin. HbA1c and preprocedural fasting blood glucose were similar among the patients treated with and without metformin (7.2±1.4% vs. 7.2±1.3%, P=0.95 and 162± 61 vs. 159±66 mg/dL, P=0.72). At a median of 10 months (IQR: 5-23, mean 15±13 months) after CA, 100/182 patients (55%) on metformin remained in sinus rhythm without concomitant antiarrhythmic drugs (AAD) compared to 36/89 patients (40%) not receiving metformin (P=0.03). On K-M analysis, patients on metformin were more likely to stay in sinus rhythm after CA, with or without AADs (P<0.001, log-rank, Figure). On Cox proportional hazards analysis, adjusted for age, gender, BMI, type of AF(paroxysmal vs. non-paroxysmal), fasting blood glucose, AAD use, obstructive sleep apnea, chronic kidney disease, and left atrial diameter, metformin use was associated with a ~35% lower probability of recurrent atrial arrhythmia(HR: 0.65, ±95% CI: 0.44-0.97, P=0.04). Increase in left atrial diameter (per mm, HR: 1.05, ±95% CI:1.01-1.08, P=0.001) and non-paroxysmal AF (HR: 1.9, ±95% CI: 1.3-2.9, P=0.001) were associated with a higher risk of recurrence after CA of AF.

Conclusion:
In patients with DM, the use of metformin was associated with a significant reduction in recurrent atrial arrhythmias after CA for AF independent of the other risk factors, including preprocedural glycemic control.
Abstract 15746: Chlorhexidine Irrigation Without Capsulectomy After Device and Lead Extraction in Patients With Cardiac Implantable Device Infection
Authors: Diaz Juan C , Romero Jorge , Velasquez Jorge E , Aristizábal Julián M , Uribe William , Bastidas Oriana , Alviz Isabella , Di Biase Luigi , Duque Mauricio
Published: May 2021

Introduction:
Pocket management after device removal is unclear in patients with cardiac implantable electronic devices (CIEDs) infection. Capsulectomy has been proposed to reduce the risk of reinfection, this procedure is time consuming and requires extensive tissue debridement with a potential higher risk of hematoma formation.

Hypothesis:
The use of chlorhexidine and saline pocket irrigation without capsulectomy is effective in the management of CIED related infection.

Methods:
Patients who underwent transvenous lead extraction without capsulectomy for CIED-related infection were included. After complete hardware removal, thorough scrubbing of the generator pocket with 20 cc of 2% chlorhexidine followed by irrigation with 1L of saline was undertaken. The pocket was dried using sterile drapes and the wound was closed with separate intradermal absorbable suture. Implantation of a new CIED device and antibiotic treatment were given according to treating physicians’ discretion. Patients were followed up for 6 weeks after the procedure, and then every 6 months.

Results:
Between July 1
st
, 2013 and May 1
st
, 2019, 34 patients (68.1±10.6 years; 13 female) were included. Median follow-up was 745.5 days (IQ range 444.5-1418 days). Lead or device extrusion (41%) was the most frequent indication for extraction. Additionally, 38% of patients had endocarditis. In 75% of cases, bacteria were isolated from blood, pocket or lead tip cultures. Gram positive bacteria were the most frequently found organisms (59% of cases). In total, 19 patients (56%) had a new device implanted after the procedure; mean follow-up for this group of patients was 1251.1±678.8 days. Average time between device extraction and implant of a new device was 26 days, with 11 patients (32%) having device implant in the following week after extraction, including three patients (9%) who underwent dual chamber pacemaker immediately after lead extraction. There were no immediate or 30-day complications associated with chlorhexidine use. During follow-up, no patients presented recurrent infection.

Conclusions:
The use of chlorhexidine and saline pocket irrigation without capsulectomy offered excellent results with no cases of reinfection and without taking the risk of hematoma formation.
Abstract 15752: Acute Kidney Injury and Shock Severity for Mortality Risk Stratification in Cardiac Intensive Care Unit Patients
Authors: Padkins Mitchell R , Breen Thomas , Barsness Gregory W , Kashani Kianoush , Jentzer Jacob C
Published: May 2021

Introduction:
Acute kidney injury (AKI) is a highly prevalent risk factor for mortality among patients with cardiogenic shock (CS). We sought to assess the incidence and prognostic relevance of AKI as a function of shock severity in unselected Cardiac Intensive Care Unit (CICU) patients, as measured by the Society for the Cardiovascular Angiography and Interventions (SCAI) shock stage.

Methods:
We retrospectively reviewed admissions to the Mayo Clinic from 2007 to 2015 and stratified patients by the SCAI shock stage. AKI was defined and staged based on changes in serum creatinine during hospitalization as per KDIGO guidelines. Predictors of in-hospital mortality were analyzed using Kaplan-Meier survival analysis, and one-year mortality was analyzed using Cox proportional-hazards analysis.

Results:
The final study population included 10,004 unique patients with a mean age of 67 years and 37% females. The percentage of patients with SCAI shock stages A, B, C, D, and E were 47%, 30%, 15%, 7%, and 1%, respectively. AKI of any severity occurred in 51% of patients during hospitalization, including severe (stage 2/3) AKI in 16%. The incidence of AKI and severe AKI increased with the SCAI shock stage. Hospital mortality occurred in 8% of patients and increased as a function of the AKI stage and SCAI shock stage. AKI was associated with increased hospital mortality after multivariable adjustment (adjusted OR per AKI stage 1.17, 95% CI 1.05-1.30, p=0.005). Twenty-one percent of patients died within one year of CICU admission, and worse AKI was associated with increased one-year mortality (adjusted HR per AKI stage 1.11, 95% CI 1.05-1.18, p=<0.001). Hospital survivors with AKI of any severity had higher mortality compared with patients who did not have AKI (p<0.001).

Conclusions:
AKI was increasingly common in CICU patients with higher shock severity. In-hospital and one-year mortality risk increased as a function of the severity of AKI and the SCAI shock stage. This analysis emphasizes the importance of AKI as a complication of shock and as a predictor of adverse outcomes in CICU patients.
Abstract 15755: Differences in Patient Characteristics of Peripartum Spontaneous Coronary Artery Dissection
Authors: Haque Nowrin , Kim Esther S
Published: May 2021

Background:
Spontaneous coronary artery dissection (SCAD) is an important cause of acute myocardial infarction in women. The peripartum period, defined as the last month of pregnancy to three months post-delivery, is known to be associated with SCAD. However, differences in patient characteristics between those with non-peripartum SCAD (npSCAD) and peripartum SCAD (pSCAD) are ill-defined. It is also unknown if the prevalence of extracoronary vascular abnormalities (EVAs) or SCAD recurrence differ between patients with npSCAD and pSCAD.

Methods:
Patients presenting to a dedicated SCAD clinic were enrolled in a single-center registry. Baseline characteristics, SCAD presentation, lab and imaging results, and recurrent SCAD events were assessed. All patients were screened for EVAs, defined as fibromuscular dysplasia (FMD), aneurysm, pseudoaneurysm, and dissection with cross-sectional imaging. Patient characteristics, clinical presentation, presence of EVAs, and recurrent SCAD events were stratified by peripartum status.

Results:
125 SCAD patients were identified from June 2016 to March 2020. Mean age (SD) at 1st SCAD event was 45.8 (10.1) years, 94.4% were female, and 15.2% (19/125) of patients were peripartum. Differences in patient characteristics between npSCAD and pSCAD are outlined in the table. npSCAD patients were older (47.5 (9.76) vs 35.6 (0.93), p= 0.0001) at the time of their 1st SCAD event and had increased rates of hypertension (35.6% (37/105) vs 11.1% (2/18), p=0.04). Those with pSCAD had higher rates of SCAD in the left anterior descending artery (LAD) (64.8% (64/125) vs 89.5% (17/19), p=0.03). There was no significant difference in the prevalence of EVAs or SCAD recurrence between npSCAD and pSCAD.

Conclusion:
Peripartum SCAD is associated with higher rates of dissection in the LAD compared to non-peripartum SCAD. There is no difference in prevalence of EVAs or recurrent SCAD in patients presenting with pSCAD.
Abstract 15762: Intensive Weight Management Improves Functional Capacity in Heart Failure With Preserved Ejection Fraction
Authors: El Hajj Milad , El Hajj Elia , Sykes Brandon , Baxley Renee , Lamicq Melissa , Ashe Tanja , Zile Michael R , Malcolm Robert , O'Neil Patrick , Litwin Sheldon
Published: May 2021

Background:
Obesity is associated with incident heart failure (HF), particularly HF with preserved ejection fraction (HFpEF). Weight loss is difficult to achieve in patients with limited physical capacity and the benefits remain uncertain in established HF.

Methods:
Patients with EF > 50% and at least 1 objective criteria for HFpEF (BNP 200 pg/ml, elevated resting or exercise wedge pressure (15 or 25 mmHg) or pulmonary edema on CXR) and BMI 30 kg/m2 were enrolled in a 15-week weight management program that entailed weekly counseling, weight checks, and meal replacement (twice daily weeks 1-8, once daily weeks 9-12). Primary endpoints were change from baseline to 15-weeks for weight, Minnesota Living With HF (MLWHF) score and 6 minute walk (6MW). Paired t-test was used to test for differences from baseline to the 15 week clinical endpoint, and one-way ANOVA was used to evaluate if these differences persisted at 26 week follow up.

Results:
65 patients signed consent, 41 completed the 15-week program and 37 had 26-week follow up. Mean age was 67±9 years, BMI 41±6 kg/m
2
, 65% were female, and 43% black. Mean weight decreased by 8.1±6.6 kg at the 15-week endpoint (p<0.001) and persisted at 26-week follow up (p<0.001). 74% of patients lost more than 5% of their baseline body weight at week 15. Blacks lost a mean of 6±6% body weight compared to 9±4% in Caucasians (p<0.05). At 15 weeks, mean 6MW distance increased from 221±111 m to 286±99 m (p<0.001) and then fell to 275±144 m at 26 weeks (p=0.043). MLWHF score improved from 60±24 to 38±27 (p<0.001) and 38±26 (p<0.001) at 15 and 26 weeks, respectively. BNP did not change (109 to 114 pg/ml). E/e’ decreased significantly from 13.9±6.8 to 11.9±5.6 at 26 weeks follow up (p<0.01). BNP levels decreased by 39±103 pg/ml in blacks vs. an increase of 17±53 mg/dl in Caucasians (p<0.05) at 15-week follow up.

Conclusions:
Clinically relevant weight loss is possible in patients with established HFpEF and when it occurs, this is associated with significant improvements in quality of life and exercise capacity. There may be racial differences in the biochemical response to weight management in this population.
Abstract 15794: Role of Endothelial Shear Stress and Endothelial Shear Stress Gradient in Plaques Associated With Acute Erosion vs. Stable Control Plaques
Authors: Hakim Diaa A , Pu Zhongyue , Coskun Ahmet U , Pinilla-Echeverri Natalia , Kajander Olli A , Maynard Charles , Cefalo Nicholas V , Cormier Michelle A , Siasos Gersimos , Papafaklis Michail I , Michalis Lampros K , Kostas Stefanu , Croce Kevin , Sheth Tej , STONE Peter H
Published: May 2021

Introduction:
The role of endothelial shear stress (ESS) in the natural history of plaque growth and TCFA formation/destabilization has been studied, but the role in plaque erosion is unknown. High ESS gradient (ESSG) has been hypothesized to promote plaque erosion, but no studies have included matched “control” stable plaques with the same minimal luminal area (MLA) and reference luminal area (RLA) but no adverse coronary event.

Hypothesis:
To compare ESS and ESSG between coronary plaques that developed erosion and similar morphology plaques that remain stable.

Methods:
We studied a subset of patients from both TOTAL and COMPLETE trials who underwent angiography and OCT evaluation: 27 patients (27 arteries: 18 LAD, 3 LCX, 6 RCA). Plaques were divided into Plaque Erosion (n=16) from TOTAL study with OCT features of plaque erosion and Control (n=11) plaques (non-culprit lesions from COMPLETE) with matched MLA and RLA and no OCT evidence of plaque disruption. Orthogonal angiographic views were used to generate a 3-D arterial reconstruction, and angio centerline was merged with OCT centerline. Local ESS distribution was assessed by computational flow dynamics and reported in consecutive 3-mm segments.

Results:
Table 1 shows differences in ESS between Plaque Erosion and Control Plaques

Conclusions:
In coronary plaques with similar severe obstruction (MLA) and reference area (RLA), plaque erosion is associated with higher coronary flow, max ESS, and ESSG in any direction, in the proximal-to-distal direction, and in the circumferential direction compared to plaques that remain stable. Future studies will determine which "feature (s)" of high ESS or ESSG are independently associated with erosion.
Abstract 15952: Gut Microbiota and Insulin Resistance in Heart Failure
Authors: Mamic Petra , Lancaster Samuel , Snyder Michael
Published: May 2021

Introduction/Hypothesis:
Insulin resistance (IR) and heart failure (HF) are closely interconnected - IR is a risk factor for HF and can develop as a consequence of chronic HF. Dysregulation of the gut microbiota (GMB) has been independently associated with both HF and IR, with many overlapping GMB features. We hypothesized that the HF-associated GMB changes may be confounded by concomitant IR.

Methods:
Our study recruited 60 non-diabetic adults with non-ischemic cardiomyopathy and HF. As controls we included 49 non-diabetic adults. We profiled GMB using whole genome sequencing. Degree of IR was assessed by fasting Homeostatic Model Assessment of IR (HOMA-IR).

Results:
Study participants were largely middle aged (median age 53.6 years), white (65%), and overweight (median body mass index (BMI) 28.5 kg/m2). Men were over-represented in the HF group, compared to controls (78% vs 48%). Mean left ventricular ejection fraction was 30.5% in the HF group, and most HF patients had mild symptoms. Both groups had elevated HOMA-IR (median 2.5). According to beta-diversity analysis based on Bray-Curtis distances, both taxonomic and functional GMB structure were significantly different in HF, compared to controls (ANOSIM p<0.001) (Figure 1). Similar analysis of IR-associated GMB structure did not show significant separation (Figure 2). Taxa and metabolic pathways contributing to HF-associated GMB differences (Table 2) remained significant after controlling for HOMA-IR, age, sex, race, and BMI.

Conclusions:
We confirmed independent association between HF and taxonomic and functional GMB community shifts, but did not demonstrate a direct relationship between comorbid IR (as measured by HOMA-IR) and the GMB changes in HF. More precise and accurate measurement of IR than HOMA-IR may be needed to allow better characterization of the GMB-IR relationship in HF, and hopefully enable identification of novel preventative, diagnostic, and therapeutic targets in this disease.
Abstract 15963: Microrna Biophysically Modulates Cardiac Physiology via Directly Binding to Ion Channel
Authors: Yang Dandan , Wan Xiaoping , Dennis Adrienne T , Bektik Emre , Wang Zhihua , Costa Mauricio G , Fagnen Charline , Vénien-Bryan Catherine , Xu Xianyao , Hund Thomas J , Mohler Peter J , Laurita Kenneth R , Deschenes Isabelle , Fu Ji-Dong
Published: May 2021

Background:
Cardiac arrhythmias are a leading cause of morbidity and mortality. MicroRNAs (miRs) regulate the (electro) physiology of the heart and remodeling by canonical RNAi mechanism.

Hypothesis:
miRs maintain cardiac physiology also through noncanonical mechanisms.

Methods:
The physical binding between cardiac predominant miR--miR1 and ion channels was explored by EMSA,
in situ
PLA, RNA pull down and RIP assays. Electrophysiology of cardiomyocytes (CMs) and
ex vivo
miR1-deficient hearts were studied to reveal the functional outcome and the pathophysiological significance.

Results:
miR1 physically binds with an inward rectifier K
+
channel Kir2.1, which exists endogenously in CMs. This miR1-Kir2.1 binding is evolutionarily conserved. Functionally, miR1, at sub-pmol/L concentration, significantly suppresses IK1, depolarizes resting membrane potential, and prolongs final repolarization of action potentials in CMs. Mechanistically, miR1 binds to the pore-facing G-loop of Kir2.1 though the core sequence AAGAAG, which is outside the seed region. This biophysical modulation is involved in the dysregulation of a gain-of-function mutation Kir2.1-M301K in short-QT/AF patients. An AF-associated miR1-hSNP14A/G specifically disrupts the biophysical modulation while maintains miR1’s RNAi function. Significantly, miR1 but not hSNP14A/G eliminates the high inducibility of arrhythmia in miR1-deficient hearts.

Conclusion:
We reveal a novel function of miRs and develop a ground-breaking concept that endogenous miRs can physically bind with ion channels and rapidly modulate cardiac electrophysiology before its long-term effect of conventional RNAi mechanism. Our study provides more comprehensive understanding of ion-channel dysregulation associated with cardiac arrhythmias.
Abstract 15981: Cost-effectiveness of Dapagliflozin in Heart Failure With Reduced Ejection Fraction
Authors: Isaza Nicolas , Calvachi Paola , Raber Inbar , Shen Changyu , Gavin Michael C , Garan A. Reshad , Bellows Brandon K , Kazi Dhruv S
Published: May 2021

Introduction:
In May 2020, the US FDA approved the use of dapagliflozin, an SGLT2 inhibitor, for the reduction of cardiovascular death and heart failure hospitalization in patients with heart failure with reduced ejection fraction (HFrEF). We examined the cost-effectiveness of adding dapagliflozin to guideline-directed medical therapy (GDMT) in patients with or without diabetes.

Methods:
We developed a state-transition Markov model with inputs from the DAPA-HF trial, FDA review documents, published literature, and nationally representative datasets (Panel A). The model was calibrated to event rates observed in DAPA-HF; survival was extrapolated using non-parametric approaches. The main outcomes were quality-adjusted life years (QALYs) and incremental cost effectiveness ratio (ICER) of dapagliflozin + GDMT compared with GDMT alone, from a healthcare sector perspective and a lifetime analytic horizon. We applied a discount rate of 3% per year for future costs and benefits, and assumed a willingness-to-pay threshold of $100,000 per QALY gained. In sensitivity analyses, we examined subgroups with or without diabetes, and varied the cost of dapagliflozin (base case = $6,188 per year). This analysis was independent of the trial sponsor.

Results:
Compared with GDMT alone, adding dapagliflozin produced 0.57 additional QALYs at an incremental cost of $56,650, producing an ICER of $98,700 per QALY gained (Panel B). In subgroup analyses, dapagliflozin produced 0.71 additional QALYs in patients with diabetes at an ICER of $89,100 per QALY gained, and 0.48 additional QALYs in patients without diabetes at an ICER of $108,800 per QALY (Panels C and D). A 9% price reduction (to $5,613 per year) would make dapagliflozin cost-effective in patients without diabetes.

Conclusions:
Adding dapagliflozin to GDMT in patients with HFrEF is cost-effective and has the potential to improve long-term outcomes. Scalable strategies to improve access and uptake are urgently required.
Abstract 15984:
Rpl13a
Small Nucleolar RNAs Promote Oxidative Stress and Atherosclerosis
Authors: Zhang Lisheng , Wu Jiaohui , Vista Andrew J , Brian Leigh , Bai Yushi , yin xinhe , Ho Hsiang-Ting , Zhu Yinzhou , Holley Christopher L , FREEDMAN Neil J
Published: May 2021

Reactive oxygen species (ROS) contribute to atherogenesis. An unusual mechanism that increases cellular ROS levels and oxidative stress involves 4 ubiquitously expressed noncoding small nucleolar RNAs (snoRNAs) from introns of the ribosomal protein L13a (
Rpl13a
) locus:
U32a
,
U33
,
U34
, and
U35a
. We tested the hypothesis that these snoRNAs promote aortic smooth muscle cell (SMC) activation and vascular inflammation, by using “snoKO” mice with targeted deletion of the 4 snoRNAs (but not
Rpl13a
). Compared with congenic WT SMCs, snoKO SMCs showed 40±20% lower ROS levels, assessed by DCF fluorescence (
p
<0.02). Congruently, ROS levels were 35±5% lower in snoKO than WT aorta and carotid frozen sections (
p
<0.01), assessed by CellROX Orange fluorescence. Proliferation and migration evoked by FBS and PDGF-BB, respectively, were each 30±10% less in snoKO than WT SMCs (
p
<0.01 for each). To assess SMC migration and proliferation in vivo, we performed carotid artery endothelial denudation. Before injury, snoKO and WT carotid arteries were morphologically equivalent. Four wk after injury, carotid neointimal hyperplasia was 57±9% less and luminal area was 40±20 % more in snoKO than in WT mice (
p
<0.01). WT and snoKO mice had equivalent heart rates and systolic blood pressures by tail-cuff plethysmography: 480±20 vs 420±80 beats/min; 133±5, 132±7 mm Hg, respectively (n=5/group). To test whether snoRNAs affect atherosclerosis, we orthotopically transplanted carotid arteries from WT and snoKO mice into congenic

Apoe
-/-

mice. Six wk post-op, atherosclerotic neointima was 70±10% smaller in snoKO than in WT carotids (
p
<0.01). To assess SMC-to-foam-cell transdifferentiation, which is ROS-dependent, carotid cross-sections were stained for apoE to identify graft-derived cells and for cholesteryl ester with BODIPY. BODIPY
+
foam cells comprised 21±3% and 11±7% of neointimal area in WT and snoKO carotids, respectively (
p
<0.05). Confocal co-localization of apoE and BODIPY (optical slice thickness 1 μm) showed that graft-derived foam cells were 2.0±0.6-fold more prevalent in WT than in snoKO carotids (
p
<0.01). We conclude that
Rpl13a
snoRNAs promote SMC ROS levels, proliferation and migration in vitro and in vivo, and that these snoRNAs augment atherosclerosis.
Abstract 15990: Incidence and Outcomes of Elevated Troponins in Patients With Rhabdomyolysis
Authors: Ganta Nitheesha , Gonzalez Hilda , Olufajo Olubode , Mehrotra Prafulla P
Published: May 2021

Introduction:
The relationship between rhabdomyolysis and elevated troponins has not been clearly established. Literature has been limited to case reports and small single center studies. However, there are no studies that evaluated the incidence and outcomes of troponin elevation in patients with rhabdomyolysis.

Methods:
Patients of 18 years and older with rhabdomyolysis were selected from the Healthcare Cost and Utilization Project National Inpatient Sample, 2005 to 2014. Patients with elevated troponins were identified. Information on demographics, co-morbidities and interventions (percutaneous coronary intervention (PCI) vs. no PCI) were extracted. The two main outcomes were mortality and hospital cost. Differences in characteristics and outcomes of patients with elevated troponins and those without elevated troponins were evaluated using descriptive analyses and multivariate regression models.

Results:
A total of 404,369 rhabdomyolysis participants were identified with 24,986 (6.18%) having elevated troponins. Of these, only 133 (0.03%) patients underwent PCI. Compared to the patients without elevated troponins, patients with elevated troponins were older (69y vs. 61y;
P
<0.001), and the majority were white (73.9% vs. 66.0%;
P
<0.001). In-hospital mortality in patients with elevated troponins was 20.5% compared to 5.4% in patients without elevated troponins (
P
<0.001) resulting in an adjusted odds ratio of 4.05 (95% CI: 3.90 - 4.20). Compared to the patients without elevated troponins, the median hospital cost in patients with elevated troponins was $17,308 vs. $8,434 (
P
<0.001) resulting in an adjusted mean difference of $9,547 (95% CI: $9,189 - $9,904).

Conclusions:
Our analysis showed that 6.1% of rhabdomyolysis patients have elevated troponins. Of these, very few patients underwent PCI, suggesting myocardial injury in these patients. Patients with elevated troponins had higher in-hospital mortality and increased cost of hospitalization. Due to the bad prognosis associated with elevated troponins, there is need for further evaluation for underlying coronary artery disease in patients with myocardial injury.
Abstract 15997: First-phase Ejection Fraction is a Powerful Predictor of All-cause Mortality in Patients With Covid-19
Authors: XIE Mingxing , Sun Zhenxing , Fang Lingyun , Xie Yuji , Zhang Li
Published: May 2021

Background:
Right ventricular (RV) strain in COVID-19 is predictive of outcome but whether the presence of left ventricular (LV) dysfunction is associated with outcomes is not known.

Objective:
The objective of the present study was to examine the association of first-phase ejection fraction (EF1), a robust and simple measure of early left ventricular systolic function, that may be a more sensitive marker of left ventricular systolic function than previously described imaging indices.

Methods:
Consecutive patients with COVID-19 (n=129) hospitalised at the West Branch of Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China, who underwent echocardiography were studied. Association of EF1, with clinical and laboratory characteristic and outcomes was performed using Cox regression analysis.

Results:
No patient with preserved EF1 (≥ 25%, a pre-defined threshold) died but 21 patients with reduced EF1 (<25%) died (P<0.001). In Cox multiple regression analysis (incorporating all factors that were associated with mortality on univariate analysis), survival was associated with RV longitudinal strain (HR: 1.23, 95%CI: 1.05-1.44, p=0.009), EF1 (HR: 0.87, 95%CI:0.76-0.99, p=0.038) and high sensitivity cardiac troponin (HR: 1.34, 95%CI: 1.07-1.69, p=0.012) but not with patient demographics, clinical characteristics or other echocardiographic measures.

Conclusion:
Early LV systolic dysfunction is a powerful predictor of outcomes in patients with COVID-19.
Abstract 15999: Machine Learning to Identify Patients at High Risk for Peripheral Arterial Disease From Electronic Health Record Data
Authors: Sonderman Mark , Farber-Eger Eric , Aday Aaron W , Freiberg Matthew S , Beckman Joshua A , Wells Quinn
Published: May 2021

Introduction:
Peripheral arterial disease (PAD) is a common and underdiagnosed disease associated with significant morbidity and increased risk of major adverse cardiovascular events. Targeted screening of individuals at high risk for PAD could facilitate early diagnosis and allow for prompt initiation of interventions aimed at reducing cardiovascular and limb events. However, no widely accepted PAD risk stratification tools exist.

Hypothesis:
We hypothesized that machine learning algorithms can identify patients at high risk for PAD, defined by ankle-brachial index (ABI) <0.9, from electronic health record (EHR) data.

Methods:
Using data from the Vanderbilt University Medical Center EHR, ABIs were extracted for 8,093 patients not previously diagnosed with PAD at the time of initial testing. A total of 76 patient characteristics, including demographics, vital signs, lab values, diagnoses, and medications were analyzed using both a random forest and least absolute shrinkage and selection operator (LASSO) regression to identify features most predictive of ABI <0.9. The most significant features were used to build a logistic regression based predictor that was validated in a separate group of individuals with ABI data.

Results:
The machine learning models identified several features independently correlated with PAD (age, BMI, SBP, DBP, pulse pressure, anti-hypertensive medication, diabetes medication, smoking, and statin use). The test statistic produced by the logistic regression model was correlated with PAD status in our validation set. At a chosen threshold, the specificity was 0.92 and the positive predictive value was 0.73 in this high-risk population.

Conclusions:
Machine learning can be applied to build unbiased models that identify individuals at risk for PAD using easily accessible information from the EHR. This model can be implemented either through a high-risk flag within the medical record or an online calculator available to clinicians.
Abstract 16001: Recurrent Vasospastic Angina Caused by Electronic Cigarette Usage
Authors: Wopperer Samuel , Safren Lowell , Masson Ravi , Malik Awais , Barnett Christopher
Published: May 2021

Introduction:
A 45 year old female with a past medical history significant for tobacco use disorder presented for evaluation of substernal pressure with radiation to the left shoulder, nausea, and dizziness. There was no associated shortness of breath, diaphoresis, or palpitations. Her symptoms were not associated with exertion.

Hypothesis:
The differential diagnosis for this atypical chest pain included unstable angina, microvascular angina, vasospastic angina, Takotsubo syndrome, and anxiety.

Methods:
An ECG revealed ST-segment elevations in the inferior leads, and an emergent coronary angiography demonstrated no significant atherosclerotic disease. However, her right coronary artery was found to be in vasospasm. Nitroglycerin was administered and relieved her chest pain, and her ECG changes returned to baseline after the episode. This fulfilled COVADIS criteria, and a diagnosis of vasospastic angina was made.

Results:
The patient was treated with nitroglycerin and a calcium channel blocker. She stopped smoking cigarettes and symptoms did not recur. Five years later, the patient again presented with similar symptoms. She reported that she had recently started smoking electronic cigarettes. The patient was counseled to stop using electronic cigarettes. One month later, the patient reported no further episodes of chest pain.

Conclusions:
We report a case of vasospastic angina caused by electronic cigarette use. Cardiac toxicity from electronic cigarettes is believed to result from exposure to nicotine as well as other chemicals including synthetic vitamin E, aldehydes, and metals present in electronic cigarettes. Though the concentration of nicotine in the blood of electronic cigarette users is highly variable, some reports describe levels comparable to or higher than those in patients who use paper cigarettes. In this patient, cessation of electronic cigarette smoking was effective in eliminating symptoms of vasospastic angina.