bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 15815: Non-Contrast Computed Tomography Attenuation Measurement for Early Detection of Aortic Valve Microcalcifications
Authors: Akhtar Hamza , Geers Jolien , Pressman Gregg S , dweck marc
Published: December 2023

Introduction:
Calcific aortic stenosis (AS) is often diagnosed at its late stage. 18F- sodium fluoride (18F-NaF) PET can identify areas of active calcification before appearance of macrocalcifications.

Hypothesis:
We hypothesized that CT attenuation measurement could detect areas of microcalcification as determined by 18F-Na F PET.

Methods:
18F-NaF PET/CT data were evaluated in 102 patients (age 71 ± 8 years, 21% female) with calcific AS at baseline and 2-year follow-up. Multiple 3 mm regions of interest were identified based on 18Na-F PET uptake and presence of macrocalcification (Hounsfield units, HU>130): PET-/CT-, PET+/CT- and PET+/CT+. Assessment of CT attenuation was also performed in 20 control patients with no AS at baseline and after 1 year.

Results:
At baseline, PET+/CT- regions had greater HU than PET-/CT- regions (median 50 [IQR 42-55] vs. 39 [IQR 32-46]; p < 0.001). Further, PET+/CT- regions showed greater 24-month change vs PET-/CT- (median 16 [IQR) 7-28] vs. 0.83 [IQR -2.56-6.91]; p < 0.001) (Figure 1). A cut off value of 48.76 HU yielded sensitivity/specificity of 57%/85% for detection of microcalcifications, AUC = 0.760. Applying this threshold to the control group the calculated 24-month increase in HU was greater in patients above the threshold vs those below (median 9.89 [IQR -2.92-29.82] vs. 0.57[IQR -7.16-4.31]; p < 0.001) (Figure 2).

Conclusions:
Aortic valve non-contrast CT X-ray attenuation value above 48.76 HU was able to identify regions of 18F-NaF uptake in patients with AS. Therefore, measuring X-ray attenuation on non-contrast CT has the potential to identify regions of developing microcalcification within the aortic valve.
Abstract 15826: Single-Cell Analysis of Right Ventricle Combined With AI: Implications for Pulmonary Arterial Hypertension
Authors: Dekan Aleksandr , James Joel , Niihori Maki , Rafikov Ruslan , Rafikova Olga
Published: December 2023

Background:
Pulmonary arterial hypertension (PAH) significantly compromises the functionality of the right ventricle (RV). Our recently established NFU1 mutation-based rat model spontaneously develops PAH and successfully recapitulates main features of human PAH, such as gender dimorphism, right ventricle (RV) hypertrophy and dysfunction with RV-pulmonary artery uncoupling.

Objective:
We aimed to discern unique transcriptional differences between in WT and NFU1 rats on the single cell level, which may shed light on potential therapeutic targets for RV hypertrophy in PAH.

Methods:
We performed a single-cell transcriptomics analysis of WT and NFU1 RV collected from WT and NFU1
G206C
rats to determine potential targets for treating RV dysfunction. The single-cell data was processed, and cells were annotated. Differentially expressed (DE) genes in cell types between the WT and NFU1 were determined using a two-sided Wilcoxon rank sum test. Finally, PandaOmics AI was employed to select through RV transcriptomics data (Boucherat, 2022) and extract the top 300 human targets from our key gene findings in the rat model.

Results:
We identified several cell types in rat scRNA-seq data, among which cardiomyocytes and endothelial cells had the highest number of human-relevant rat targets. Endothelial cells had 6 targets, Hsp90aa1/b1, Fabp4, Fhl2, Tnni3, Atp2a2, Ndufa4. These genes can affect endothelial cell proliferation, vascular integrity, intracellular transport, and angiogenic phenotype. Cardiomyocytes had 24 identified targets responsible for increased mitochondrial metabolism (Ndufv1, Nme2, Mrpl15), calcium release and muscle contraction (Ryr2, S100a1, Atp2a2), and others.

Conclusions:
A distinct disparity is observed in the transcriptional landscape in RV in NFU1 model of PAH. This could either indicate an adaptive response by the RV to increased afterload or be tied to its distinctive embryological/developmental origin, morphology, and functional properties. Novel cell-type-specific potential targets responsible for RV hypertrophy and dysfunction in PAH were discovered.
Abstract 15827: Impact of Harvesting Techniques on Coronary Bypass Conduit Endothelial Cells and Collagen Exposure Using Ligand-Based Targeting
Authors: Bahatyrevich Nataliya , Ramasubramanian Lalithasri , Hao Dake , Loll Emma , Lopez Juan-Maria G , Kwong Mimmie , Wozniak Curtis J , Evans Sabrina A , CATRIP JORGE , Kiaii Bob , Wang Aijun
Published: December 2023

Background:
Coronary bypass is a mainstay therapy for coronary artery disease (CAD). Conduit options include the internal thoracic artery (ITA), radial artery (RA), and great saphenous vein (GSV). Long-term patency rates are >95% (ITA), 75% (RA), and 50% (GSV) at 10 years. The impact of harvesting techniques on endothelial cells is not well understood.

Hypothesis:
We hypothesized that observed differences in patency rates could potentially be explained by differences in endothelial cell response to a harvesting technique.

Aims:
1) Determine degree of endothelial cell damage between different conduits and various harvesting techniques. 2) Assess ability of a specific collagen binding peptide SILY to bind to exposed collagen in GSV.

Methods:
De-identified human graft samples of ITA, RA, and GSV were collected and analyzed from September 2021 through February 2023. The harvesting techniques were open for ITA and GSV, endoscopic for RA, and endoscopic for GSV. The samples were fixed and stained with anti-CD31 antibody to identify endothelial cells on the luminal surface with
enface
imaging. Binding of SILY peptide to GSV was tested at different concentrations and incubation times.

Results:
51 specimens were obtained, 18 open ITA, 10 open GSV, 18 endoscopic GSV, and 5 endoscopic RA. Luminal surface covered by endothelial cells was 86.6±8.1% for ITA, 76.7±14.7% for RA, 58.3±14.0% for endoscopic GSV, and 59.0±5.5% for open GSV. Endothelial coverage area on ITA samples was significantly higher compared to endoscopic GSV, open GSV, and RA (p<0.05). Endothelial coverage area on RA samples was significantly higher compared to endoscopic GSV and open GSV (p<0.05). There was no statistically significant difference in endothelial coverage area between open and endoscopic GSV (p=0.43). Testing of SILY binding revealed colocalization with collagen fibers on luminal surface of GSV samples.

Conclusions:
Microscopic examination showed greatest preservation of endothelial cells on ITA followed by RA and GSV with no difference between open and endoscopic GSV. Targeting of exposed collagen with SILY in the areas of damaged endothelium might be a good approach for therapeutics in the future.
Abstract 15875: Immediate Complete Revascularization Reduces Recurrent Myocardial Infarction and Repeat Revascularization in Patients Presenting With Acute Myocardial Infarction
Authors: Upreti Alina , Upadhaya Sunil
Published: December 2023

Introduction:
Studies have suggested that complete revascularization has better outcome compared with culprit-only revascularization for the treatment of enzyme-positive acute coronary syndrome. However, the optimal timing of complete revascularization remains unclear. We conducted a meta-analysis of randomized controlled trials (RCT) comparing immediate complete revascularization with staged revascularization in patients with ST-segment elevation myocardial infarction (STEMI) or non-ST-segment elevation myocardial infarction (NSTEMI) with multi-vessel disease.

Methods:
We systematically searched the Cochrane Central Register of Controlled Trials, Embase, PubMed and clinicaltrials.gov databases for RCT comparing immediate complete revascularization with staged revascularization in patients with enzyme-positive acute coronary syndrome. The pooled outcome were major cardiovascular adverse event (MACE), all-cause death, cardiovascular death, recurrent MI and repeat revascularization. The random effect and Mantel-Haenszel method was used to analyze the data. Heterogeneity was measured using I
2
.

Results:
Five studies met the inclusion criteria ( 1187 patients in immediate complete revascularization group and 1176 patients in staged revascularization group). We did not find any significant difference in the rate of MACE (OR: 0.75 [95 % CI: 0.44-1.29] I
2
: 35%, p value = 0.30). Similarly, there was no significant difference in the rates of all-cause death (OR: 0.93 [95 % CI: 0.47-1.86] I
2
: 40%, p value = 0.84)and cardiac death (OR: 1.02 [95 % CI: 0.52-1.98] I
2
: 14%, p value = 0.96). However, immediate complete revascularization group had significant reduction in the rates of repeat revascularization (OR: 0.59 [95 % CI: 0.43-0.82] I
2
: 0%, p value = 0.002) and recurrent MI (OR: 0.52 [95 % CI: 0.32-0.84] I
2
: 1%, p value = 0.008). Subgroup analysis including STEMI patients only showed similar rate of MACE ((OR: 0.92 [95 % CI: 0.60-1.41] I
2
: 0%, p value = 0.70).

Conclusions:
Our results suggest that immediate complete revascularization is safe. There was significant reduction in recurrent MI and need for repeat revascularization in patients undergoing immediate complete revascularization.
Abstract 15895: Bariatric Surgery and Subclinical Myocardial Injury
Authors: Aryee Ebenezer K , Wallace Amelia S , Zhang Sui , Michos Erin D , Echouffo Justin B , Gerstenblith Gary , Blumenthal Roger S , Chu Xin , Wood G , Benotti Peter , Hoogeveen Ron C , Ballantyne Christie M , Coresh Josef , Selvin Elizabeth , Ndumele Chiadi E
Published: December 2023

Background:
Obesity is linked with subclinical myocardial injury, even in those with metabolically healthy obesity (MHO). There is limited data on the impact of weight loss via bariatric surgery on myocardial injury, particularly at different levels of metabolic health.

Methods:
We prospectively evaluated 294 Geisinger Obesity Institute Registry participants undergoing bariatric surgery and 294 controls matched on age, sex, body mass index (BMI;± 5kg/m
2
) and diabetes status. High-sensitivity cardiac troponin I (hs-cTnI) was measured pre-operatively and at 6-18 months post-operatively in bariatric surgery patients, and at similar intervals in controls. Using linear regression, we examined the association of bariatric surgery with change in log transformed hs-cTnI (ln-hs-cTnI), stratified by metabolic health status: MHO (metabolic syndrome absent), metabolically unhealthy obesity (MUO; metabolic syndrome present), and MUO with diabetes. We used logistic regression to characterize the association of weight change (modeled as a restricted cubic spline) with the OR of transitioning from detectable to undetectable hs-cTnI (limit of detection 1.2ng/L).

Results:
The mean age was 45 years with 83% female, 97% White, and mean BMI of 47 kg/m
2
. Baseline characteristics of bariatric surgery patients and controls were similar. Bariatric surgery was associated with significant reduction in ln-hs-cTnI compared with controls in each stratum of metabolic health (P for interaction = 0.63; Panel A). Bariatric surgery was associated with an OR of 9.02 (95% CI 3.52-23.10) for transitioning from detectable to undetectable hs-cTnI, with a dose response association between weight loss and higher odds of developing undetectable hs-cTnI (Panel B).

Conclusion:
Bariatric surgery induced weight loss mitigates subclinical myocardial injury in graded fashion and across metabolic health strata, which may reflect one mechanism for the cardioprotective benefits of weight loss.
Abstract 15900: Probing Mitochondrial Dysfunction in Mouse Hearts With Doxorubicin-Induced Cardiotoxicity Using Ungated 4D Oxy-Wavelet MRI
Authors: Cortes Devin Raine Everaldo , Stapleton Margaret , Schwab Kristina , Coulson Noah , Mazzella Elizabeth , West Dalton , Becker-Szurszewski Thomas , Hartwick Sean , Christodoulou Anthony G , Wu Yijen L
Published: December 2023

Introduction:
Despite advances in cancer therapy greatly improving patient survival, more than two-thirds of cancer survivors will still face serious life-threatening cardiomyopathy caused by anti-cancer anthracyclines. Doxorubicin (Dox), a well-known, well studied anthracycline, is a major cause for long-term morbidity and mortality among cancer survivors.
Pertinent to this issue is the lack of non-invasive imaging tools that can detect DOX induced cardiomyopathy before irreversible tissue damage is done.
Current research of cellular mechanisms underlying DOX-induced cardiotoxicity has shown that mitochondrial dysfunction are central to this cardiomyopathy.

Hypothesis:
We hypothesize that this mitochondrial dysfunction precedes clinical changes in cardiac strain and left-ventricle ejection fraction.

Methods:
To probe mitochondrial function non-invasively, we use motion-and-time resolved 4D functional MRI, coined 4D Oxy-Wavelet. Our methodology can capture dynamic changes in the blood oxygenation level dependent (BOLD) signal with high spatiotemporal resolution. Our cyclic hypoxia challenge leverages the need for in-tact mitochondrial function to maintain homeostatic oxygenation during hypoxia. We combine our 4D-fMRI methodology with a cyclic hypoxia challenge to stress-test the mitochondria in a mouse model of DOX-induced cardiotoxicity. We use a novel time-frequency analysis of the event-driven BOLD response to automate the detection of mitochondrial dysfunction in-vivo.

Results:
C57BL6/J were given Dox over the course of one week. 4D oxy-wavelet MRI was performed at baseline, day 1, 3, 4, and 7 to evaluate the ability to rapidly detect acute DOX induced cardiotoxicity. We found that as early as day one post exposure, mice exhibited a passive response to the hypoxia challenge, representing an inability to maintain homeostatic oxygen and underlying mitochondria dysfunction, that was maintained through this acute period.
Abstract 15901: Body Mass Index Threshold for Obesity Should Be Personalized Based on Polygenic Score
Authors: Kim Min Seo , Shim Injeong , Kim Beomsu , Natarajan Pradeep , Do Ron , Park Woong-Yang , Khera Amit V , Ellinor Patrick T , FAHED AKL , Won Hong-Hee
Published: December 2023

Background:
Current guidelines use body mass index (BMI) ≥30 kg/m
2
to define obesity and indicate obesity management, including lifestyle modification and anti-obesity pharmacotherapy.

Hypothesis:
The conventional BMI threshold (≥30 kg/m
2
) may have different clinical significance by the individual’s inherent genetic risk for obesity.

Methods:
Polygenic score (PGS) for BMI was calculated to quantify inherited susceptibility to obesity for 335,835 European-ancestry UK Biobank participants. We calculated odds ratio (OR) of a composite outcome (type 2 diabetes and cardiovascular outcomes [coronary artery disease, heart failure, atrial fibrillation, pulmonary embolism, venous thromboembolism, hypertension, and aortic valve stenosis]) for people living with obesity (PLwO, BMI ≥30 kg/m
2
), compared to a reference group (BMI 18.5-24.9 kg/m
2
). Using a regression model, we assessed the BMI thresholds demonstrating the equivalent OR of composite outcome in each genetic risk stratum, adjusting for clinical, lifestyle, and socio-behavioral covariates. We quantified the extent of reclassification among PLwO by using genetically-inferred BMI.

Results:
For 335,835 participants (mean age 57.37±7.99 years, 53.6% female), the genetically-inferred BMI thresholds were 29.44 kg/m
2
in the high PGS group (top 20%) and 30.62 kg/m
2
in the low PGS group (bottom 20%) for risk of composite outcome equivalent to the conventional BMI threshold. The genetically-inferred BMI thresholds diverged wider for more extreme genetic groups (i.e., top 5% PGS). With the genetically-inferred BMI threshold, 6.9% of PLwO based on conventional BMI threshold were recalibrated (either excluded or newly ascertained to PLwO).

Conclusions:
The current one-size-fits-all BMI threshold could benefit from incorporating genetic susceptibility to better define obesity health risks. Accounting for genetic risk to define the obesity BMI threshold could reclassify up to 6.9% of the PLwO.
Abstract 15913: Takotsubo Cardiomyopathy, is It Preventable?
Authors: Abdelsalam Mohammed , Abu Hassan Falah
Published: December 2023

Introduction:
Takotsubo cardiomyopathy (TCM) is a reversible type of heart failure that occurs mostly in postmenopausal women. There are no definitive preventive measures in literature for this condition.

Case:
A 75-year-old female with a past medical history of hypertension presented with a new intermittent pressure-like chest pain and dyspnea right after a 1000-miles road trip. she reported that she had been feeling sad after her best friend died. Physical exam showed bilateral lower lung lobes crepitation and hypoxia. Lab work up revealed troponin of 1522 ng/L trending up to 2400 ng/L on serial measurements and elevated BNP. EKG showed ST changes and inverted T wave. Chest x-ray showed pulmonary vascular congestion and small bilateral pleural effusion. TTE showed LVEF 25-30% and mid and apical LV hypokinesis. Chest CT angiography was normal. Left heart catheter showed nonoccluded coronary arteries. LV angiogram portrayed mid and apical hypokinesis. Serology and PCR of EBV, Coxsackie B virus, CMV, HSV, influenza A and B, adenovirus and parvo virus were negative. She was started on a diuretic, a Beta blocker and an ACE inhibitor. Her symptoms improved. A follow up echocardiogram after 1 month showed improved ejection fraction and resolution of LV mid and apical hypokinesis. Recent combined emotional and physical stress of driving a long distance were thought to be the cause of stress cardiomyopathy.

Discussion:
Approximately 1-2% of patients presenting with symptoms of MI meet the criteria for TCM. A recent systematic review by Nyman et al on triggers of TCM found that physical factors are more common than emotional factors. However, some cases had both emotional and physical stressors. This patient had combined psychological and physical stressors, which may have precipitated TCM. postmenopausal women with recent emotional stressors should be advised to avoid physical stress until emotional issues have been resolved.
Abstract 15965: Electrocardiogram-Based Artificial Intelligence Predicts Incident Heart Failure
Authors: Khurshid Shaan , Friedman Samuel , Kany Shinwan , Cunningham Jonathan , Lau Emily , Pipilas Daniel , Al-Alusi Mostafa , Ramo Joel , Pirruccello James , Nauffal Victor , Reeder Christopher , Singh Pulkit , Philippakis Anthony A , Maddah Mahnaz , Ellinor Patrick T , Ho Jennifer E
Published: December 2023

Introduction:
Heart failure (HF) is a major cause of cardiovascular morbidity. Efficient and accurate prediction of incident heart failure episodes may enable preventive efforts.

Methods:
Using raw 12-lead ECG waveforms, we developed a convolutional neural network to predict HF admissions (Electrocardiogram to Heart Failure, “ECG2HF”). ECG2HF was developed in 91,573 individuals in Massachusetts General Hospital (MGH), and validated in three independent test sets: MGH, Brigham and Women’s Hospital (BWH), and the UK Biobank, among individuals without a prior HF episode. HF events were identified using a validated natural language processing model (MGH and BWH), and inpatient diagnosis codes (UK Biobank). Discrimination was quantified using time-dependent average precision (AP) and area under the receiver operating characteristic curve (AUROC). Among individuals with available data, we compared ECG2HF to the Pooled Cohort Equations for Heart Failure (PCE-HF).

Results:
The test sets comprised MGH (15,695 individuals, age 55±17, 51% women), BWH (52,124 individuals, age 55±17, 59% women), and UK Biobank (42,135 individuals, age 65±8, 52% women). ECG2HF consistently discriminated incident HF events (MGH 10-year AP: 0.17 [95% CI 0.15-0.20], 10-year AUROC 0.88 [0.86-0.89]; BWH: 0.15 [0.14-0.17], 0.87 [0.85-0.88]; UK Biobank 3-year AP 0.036 [0.024-0.057], 3-year AUROC 0.73 [0.68-0.77]). ECG2HF risk consistently stratified longitudinal HF incidence. Compared to PCE-HF, discrimination using ECG2HF was favorable in MGH/BWH (improvement in AP 0.07 [-0.11-0.14], improvement in AUROC 0.13 [0.088-0.18]), and UK Biobank (improvement in AP 0.016 [0.0060-0.033], improvement in AUROC -0.0093 [-0.062-0.044]).

Conclusions:
Artificial intelligence-enabled analysis of the 12-lead ECG may facilitate identification of individuals at risk for HF to enable early treatment to reduce HF-related morbidity.
Abstract 16003: A Case of Ventricular Fibrillation Arrest in a Healthy Young Female With Newly Discovered Mitral Annular Disjunction
Authors: Amin Sheena , O'Gorman Brendan , Dadekian Gregory
Published: December 2023

Introduction:
Mitral annular disjunction (MAD) is an under-recognized cause of ventricular arrhythmias.

Case Presentation:
A previously healthy, athletic 43-year-old female suddenly collapsed during a staff meeting at a medical center. Cardiopulmonary resuscitation was initiated and she was found to be in ventricular fibrillation, requiring three defibrillation shocks to achieve ROSC. EKG was notable for prolonged QTc without signs of pre-excitation or Brugada syndrome. Patient denied any personal or family cardiac history but endorsed frequent palpitations in the past. No electrolyte derangements were identified. Coronary angiography revealed normal origins of the coronary arteries and no evidence of obstructive disease. Transthoracic echocardiogram demonstrated normal left ventricular systolic function, normal wall thickness, and no regional wall motion abnormalities. There was mild bileaflet mitral valve prolapse with mild mitral regurgitation and mitral annular disjunction measuring 0.7 cm. Cardiac MRI was obtained and demonstrated biventricular dilation (consistent with athlete’s heart) with evidence of MAD. The myocardium was normal with no evidence of late enhancement. She underwent dual-chamber cardioverter-defibrillator implantation for secondary prevention.

Discussion:
Mitral annular disjunction is a structural abnormality involving atrial displacement of the mitral annulus, leading to an abnormal separation between the posterior mitral valve leaflet and basal ventricular myocardium during systole. Etiology of MAD remains unclear. It is estimated to be present in 8.7% of the general population and in over 30% of individuals with mitral valve prolapse. This case presents an example of a previously healthy patient with sudden cardiac arrest. After extensive workup, MAD was identified as the most likely trigger for her new onset arrhythmia. This case highlights the severe, and potentially fatal, arrhythmias that can arise from MAD. It is important to recognize MAD seen on echocardiograms and counsel patients on potential complications. Patients with MAD and increased risk factors should undergo further evaluation with cardiac MRI and/or electrophysiology studies.
Abstract 16010: Sudden Death in the Systemic Right Ventricle: Single Center Study of Dextro-Transposition of the Great Arteries Palliated With Atrial Switch
Authors: Ahmad Rimsha , Chiriac Anca , Bhalla Jaideep Singh , Mehta Ramila , Connolly Heidi M , Egbe Alexander C , Nguyen Duy , McLeod Christopher J , Asirvatham Samuel , Madhavan Malini
Published: December 2023

Introduction:
The incidence and risk factors for sudden cardiac death (SCD) in patients with systemic right ventricle (sRV) and D-TGA palliated with atrial switch procedures is not well understood.

Methods:
This cohort was examined retrospectively for the composite end point of SCD, sustained ventricular tachycardia (VT) >30 s or appropriate ICD therapy for VT. Clinical characteristics of those with and without the end point were compared using the Kruskal-Wallis or Chi-square test as appropriate.

Results:
The composite end point occurred in 15 of 148 (10%) patients (63.5% male) at a mean age of 36.4 (SD 10.3) years. SCD occurred in 6 patients (n=2 successfully resuscitated), sustained VT in 6 patients and ICD therapy for VT in 3 patients who had previously received a primary prevention ICD. Patients with SCD/VT had lower sRV ejection fraction (EF) compared to patients without SCD/VT [28±11 vs 40±10%, P<0.001]. The odds ratio of SCD/VT in patients with sRVEF≤35% compared to sRVEF>35% was 13.3 (95% CI 2.8 - 64.4). Kaplan Meier analysis of time to SCD/VT stratified by sRV EF is presented in figure. QRS duration, QRS fragmentation, QTc and history of systemic AV valve surgery were not significantly associated with SCD/VT. Non-sustained ventricular tachycardia (NSVT) on Holter monitoring occurred more frequently in SCD/VT patients (80 vs 39%, p=0.003). All 11 survivors of SCD/VT received an ICD; appropriate ICD therapy occurred in 27% of these patients during follow-up.

Conclusion:
SCD or VT occurred in one-tenth of D-TGA patients palliated with atrial switch, predominantly in 3
rd
and 4
th
decade of life. Reduced sRV EF was the most important association and ICD implantation for primary prevention of SCD is a reasonable consideration in those with reduced sRV EF.
Abstract 16022: Evaluating the Utility of OpenAI’s GPT-4 as a Diagnostic and Management Aid in Medicine
Authors: Ge Alan , Pandya Vidish , Ferrick Kevin J , krumerman andrew
Published: December 2023

Introduction:
The advent of deep learning in artificial intelligence has led to exponential growth in its capabilities to assist in medical decision making, diagnosis, and clinical reasoning. ChatGPT has recently gained popularity in the media, and while it has the potential to revolutionize modern medicine, its effectiveness in providing clinicians actionable management options is not fully understood.

Methods:
We investigated the capabilities and limitations of GPT-4, OpenAI’s most advanced model, by comparing its clinical decision making and differential diagnosis to expert clinicians from five NEJM cases published after GPT-4’s training cutoff date (9/2021). The cases were slowly fed to the program, which was prompted to provide management and next steps at each juncture. These recommendations were then compared to the clinicians’ decision making.

Results:
GPT-4’s final diagnosis was correct for only one out of the five cases. However, it considered the correct final diagnosis in its list of five differential diagnoses in all of the cases. GPT-4’s decisions matched 18-60% of the authors’ decisions (Table 1).

Conclusion:
GPT-4 considered the correct diagnosis in its differentials for all five cases that were tested. Ultimately it was only able to correctly identify the diagnosis in one case. GPT-4’s management decisions matched that of the authors 18-60% of the time. This initially appears to be lackluster, but GPT-4 was able to offer appropriate decisions for common problems and this match rate of decisions was heavily influenced by discrete lab orders. GPT-4 was able to recommend the final diagnostic test that would reveal the diagnosis in the majority of the cases. Our study was limited by sample size as well as the fact that case distribution included only rare and difficult to diagnose diseases. This brief study shows how large language models such as GPT-4 have the potential to be used to aid in clinical decision making.
Abstract 16034: Heart Transplant in Older Adults: Outcomes in the Modern Era of Transplant
Authors: Golob Stephanie , Leiva Orly , Goldberg Randal , Kadosh Bernard , Cruz Jennifer , Nazeer Haider , Dodson John A , reyentovich alex
Published: December 2023

Introduction:
The total number and the proportion of older adults receiving heart transplants have increased over the last two decades. In 2016, the ISHLT guidelines for patients over 70 years of age were updated to remove the use of an alternate-type pool of donors, and now recommend transplanting carefully selected patients over 70 from the general pool.

Aims:
This study examines outcomes of older adults (>70) who receive heart transplants in the modern era.

Methods:
Adult patients who received heart transplant between January 1, 2010 and December 31, 2021 were identified in the United Network for Organ Sharing (UNOS) registry. Outcomes of interest were mortality at 1 and 5 years after heart transplant.

Results:
Those over 70 were more likely to be male, white, have an ischemic etiology of their heart failure, and have had a prior malignancy.

Overall mortality at 1 year was 10.8% for those over 70 and 8.9% for those under 70 (p<0.033). Overall mortality at 5 years was 12.8% for those over 70 and 19.8% for those under 70 (p=0.37).

Time to event survival analysis showed mortality was higher at 1 (HR 1.25, 1.04-1.51, p=0.019) and 5 years (HR 1.21, 1.05-1.39, p=0.006), however if patients conditionally survived the first year, 5-year conditional mortality was not different (HR 1.17, 0.95-1.43, p=0.135).

Those over 70 were less likely to suffer from rejection, more likely to die from infectious disease or malignancy, but less likely to die from cardiovascular causes or graft failure.

Conclusions:
Older adults (over 70) who receive heart transplants have slightly worse 1- and 5-year survival but similar conditional 5-year survival to those under 70—the difference is driven by mortality in the first year. Both cohorts’ survival curves are improved compared to transplants in earlier eras. Those over 70 are less likely to experience rejection, consistent with the well-described phenomenon of immunosenescence.
Abstract 16036: Concomitant Culture-Negative Left-Sided Native Valve Endocarditis With Splenic Emboli and Babesiosis: A Case Report
Authors: Bulsara Kishen , Vaysblat Michael , Bae Suhwoo , Weintraub Spencer F , Acevedo-Mendez Bernardo A , Convissar Alex
Published: December 2023

Description of Case:
A 76-year-old man with type 2 diabetes and a previously drained hepatic abscess presented with 3 days of fevers and chills associated with dizziness, weakness, and fatigue after hiking at a New York State Park. He denied any shortness of breath, chest pain, abdominal pain, diarrhea, skin rashes, insect bites, IV drug use, recent travel or sick contacts but reported having dental work one month prior to admission. Initial vital signs were notable for a fever of 38.4°C with a blood pressure of 145/76, heart rate of 90, and physical examination was unremarkable. Extensive laboratory studies were drawn, which initially were notable for normocytic anemia, thrombocytopenia, low haptoglobin and elevated lactate dehydrogenase. Empiric antibiotics were initiated as the patient met criteria for systemic inflammatory response syndrome (SIRS). CT abdomen and pelvis was remarkable for right-sided spleen with polysplenia and multiple peripheral wedge-shaped splenic infarcts. A transthoracic echocardiogram (TTE) was inconclusive for infective endocarditis (IE). A subsequent transesophageal echocardiogram (TEE) showed vegetations on the aortic and mitral valves with mild regurgitation respectively. After cardiothoracic surgery evaluation, he was deemed not a surgical candidate. Blood and urine cultures remained negative, but the Babesia antibodies IgM and IgG antibodies, and Babesia microti PCR was detected. He was started on atovaquone 750 mg twice daily and azithromycin 250 mg once daily for 10 days for babesiosis. He was discharged on vancomycin 1g every 12 hours and ceftriaxone 2g every 24 hours for a total of 6 weeks for empiric IE treatment given splenic emboli.

Discussion
:
We describe a rare case of fever caused by culture-negative mitral and aortic valvular endocarditis with splenic emboli and babesiosis. Recent dental work and hiking outdoors in the Northeast United States of America were the key predisposing factors. Given splenic infarcts, pursuing a TEE was pivotal in ascertaining the diagnosis. The patient received empiric IE treatment for gram-positive cocci, HACEK organisms and babesiosis with improvement of symptoms. Identifying and treating unusual causes of fever and SIRS are crucial in reducing mortality and morbidity.
Abstract 16045: Fluoroless Arterial Access and Closure for VT Ablation: Feasibility and Safety of an Ultrasound Guided Landmark Approach
Authors: Nelson Maxine , Gruber Megan , AlMahameed Soufian
Published: December 2023

Introduction:
Ultrasound (US) guided access has become the gold standard of care for central access cannulation. The FAUST1 trial demonstrated that routine real-time US guidance was equivalent to fluoroscopic guidance but improved common femoral artery (CFA) access success and reduced complications in patients with high CFA bifurcations. The utilization of non radiation imaging modalities over the past decade has resulted in significantly reduced radiation exposure and orthopedic problems associated with prolonged electrophysiology procedures2.

Hypothesis:
Why do many operators still use fluoroscopy and arteriograms in addition to ultrasound guided access?

Methods:
A prospective single center multi-operator study was performed on patients undergoing premature ventricular contractions (PVC) or Ventricular Tachycardia (VT) ablation with arterial access. CFA access was obtained using a US guided landmark identification protocol. US probe is utilized in short and long access to identify upper and lower borders of the femoral head in relation to the CFA bifurcation. CFA access is then obtained with a modified Seldinger approach within femoral head landmarks. After arterial sheath insertion, the artery is again evaluated for closure appropriateness, assessed by absence of arterial calcifications within 5mm of arrteriotomy or stenosis <5mm in diameter.

Results:
20 consecutive patients undergoing PVC or PVT ablation were included. All patients underwent US only guided access to the right common femoral artery. All patients underwent successful closure with a hemostasis device. There were no vascular complications.

Conclusions:
Real-time US only guided CFA access is feasible and safe. Appropriate utilization of US is sufficient to avoid intravenous contrast and radiation exposure without increased complication rate.
Abstract 16126: Sex Differences in the Relationship Between Left Ventricular Global Longitudinal Strain and Abnormal Myocardial Flow Reserve in a Patient Population With Sleep Disordered Breathing
Authors: Malczewska Magdalena , Feher Attila , McNamara Robert L , Miller Edward J , Yaggi Henry K , Thorn Stephanie , Sinusas Albert J , Aneni Ehimen
Published: December 2023

Introduction:
Obstructive sleep apnea (OSA), a form of sleep disordered breathing (SDB), is associated with abnormal myocardial flow reserve (MFR), a precursor to heart failure with preserved ejection fraction (HFPEF). Sex differences have been reported in the prevalence of abnormal MFR and OSA. However, it is unknown if there are sex differences in the relationship between left ventricular (LV) global longitudinal strain (GLS) and abnormal MFR in a patient population with SDB.

Methods:
We compared LV GLS among patients in our institution who had sleep testing for obstructive sleep apnea (OSA), cardiac PET stress test and an echocardiogram between 2015 and 2019. We reprocessed the echocardiograms using a vendor neutral software to obtain the two-dimensional LV GLS.

Results:
Among the 148 participants, 59% were female. Compared with females, males had lower BMIs, a higher prevalence of prior myocardial infarction or revascularization, and a greater severity of nocturnal airway obstruction and hypoxia. Males also had a greater proportion with abnormal LV GLS (≥ -17). See
Table.
The prevalence of abnormal MFR (< 2.0) was higher among participants with abnormal LV GLS (
P
= 0.031). This association was persistent among males but was lost among females (see
Figure
). In age and sex adjusted logistic regression persons with abnormal LV GLS had 2X the odds of abnormal MFR (OR 2.3; 95% CI: 1.02 - 5.03). Among males, this association was significant (OR 4.8; 95%CI:1.5 - 13.7). No association observed among females. Formal interaction analyses did not meet statistical significance (
P
int
= 0.106).

Conclusions:
In this patient population with SDB, there was a significant association between LV GLS and abnormal MFR. The sex differences in the relationship may be due to differences in the severity of OSA and prevalence of ischemic heart disease. Future studies should clarify these relationships and elucidate the drivers of the sex disparities observed in these findings.
Abstract 16129: The Gender Difference in Risk Factors and Incidence Rate of Ischemic Stroke in Japanese Atrial Fibrillation Patients: The Fushimi AF Registry
Authors: DOI KOSUKE , Nakanishi Yumiko , Minami Kimihito , Ishigami Kenjiro , Ikeda Syuhei , Yoshizawa Takashi , Hamatani Yasuhiro , Ide Yuya , Fujino Akiko , Ishii Mitsuru , Iguchi Moritake , Masunaga Nobutoyo , Abe Mitsuru , Akao Masaharu
Published: December 2023

Background:
Gender-specific medicine is of concern in cardiovascular medicine. We previously reported that there was not gender difference in the incidence of ischemic stroke from the Fushimi AF Registry. However, the gender difference in risk factors of ischemic stroke in Japanese atrial fibrillation (AF) patients is little known. The aim of this study is to compare the risk factors and incidence rate of ischemic stroke in male and female using the latest data with longer follow-up. Method: In the Fushimi AF Registry, follow-up data were available for 4,496 patients. In the entire cohort, 2,677 were male and 1,819 were female. We compared clinical characteristics and risk factors and incidence rate of ischemic stroke between the two groups. Result: Male patients were younger (male vs. female; 71.5 years vs. 76.7 years, p<0.01), greater in body weight (65.0 kg vs. 51.2 kg, p<0.01), were more often sustained type (52.0% vs. 48.2%, p=0.04), more likely to have diabetes mellitus (26.2% vs. 19.9%, p<0.01), coronary artery disease (16.0% vs. 12.3%, p<0.01) and less likely to have prior heart failure (24.0% vs. 32.3%, p<0.01), chronic kidney disease (CKD) (33.7% vs. 39.3%, p<0.01) and had lower CHADS
2
score (1.96 vs. 2.15, p<0.01). In prescription data, male patients more often received oral anticoagulant (58.2% vs. 52.1%, p<0.01) and antiplatelet drug (APD) (29.0% vs. 23.8%, p<0.01). Hypertension, left atrium enlargement (LAE), previous stroke and major bleeding were comparable between the two groups. During the median follow-up of 1,824 days (longest 10 years), the incidence rate of ischemic stroke was not significantly different between two groups (0.86 vs. 0.89% per person-year, log rank p=0.32). On multivariate Cox regression analysis, age, previous stroke and LAE were significantly associated with an increased risk of ischemic stroke in both groups. CKD and prescription of APD were significantly associated with an increased risk of ischemic stroke in male, while body weight was in female.

Conclusion:
The incidence rate of ischemic stroke was not significantly different between male and female. The risk factors associated with ischemic stroke were different between male and female in Japanese AF patients.
Abstract 16133: Lipoprotein(a) Screening Practices in a Large US Healthcare Dataset
Authors: McGowan Mary P , MacDougall Dianne E , Hu Xingdi , Boatwright Wess , HOWARD WILLIAM , Puhach Yuliia , Malchyk Halyna , Wilemon Katherine A
Published: December 2023

Introduction/Background:
Elevated Lipoprotein(a) [Lp(a)] is an independent, genetically determined, causal risk factor for atherosclerotic cardiovascular disease (ASCVD). European and Canadian guidelines recommend Lp(a) screening in all adults, while US guidelines recognize elevated Lp(a) as a risk enhancer.

Research Hypothesis:
Although elevated Lp(a) is an important ASCVD risk factor with a high prevalence, testing is infrequent.

Aims:
To characterize adults screened for Lp(a) and their clinicians using real-world data from the Family Heart Database of >324M US individuals with medical and/or lab data from 2012-2021.

Methods:
In this retrospective cohort study of > 44 million adults with lab data and medical claims one year before and after initial Lp(a) measurement, screening rates, demographics, ASCVD status, comorbidities, Lp(a) level (median; IQR) and ordering clinician are described.

Results:
Lp(a) screening rates were 1.1% (n=500,899 of 44,857,734) and 2.0% (n=218,331 of 10,658,820) in all and in those with ASCVD respectively. Among those with any Lp(a) test, median age was 60 (IQR 50-69) years, 55.0% were female,43.6%, 33.0%, 33.9%, and 13.9% had prior ASCVD, hypertension, hyperlipidemia and diabetes respectively. 20% had an Lp(a) level
>
139 nmol/L. Lp(a) level was higher in females than males 36 (IQR 11-118) versus 28 (IQR 10-95) nmol/L, and in Blacks versus White and Hispanic populations 73 (IQR 24-170), 29 (IQR 10-102) and 28 (IQR 10-85) nmol/L. A small number of clinicians (n=687 of 41,976; 1.6%) ordered 50% of Lp(a) tests.

Conclusions:
Measurement of Lp(a) in US adults with and without ASCVD was rare but increased substantially after 2018. Individuals who had Lp(a) assessed were older and frequently had ASCVD and comorbidities. A small number of clinicians were responsible for most Lp(a) orders. Additional research into barriers and facilitators of Lp(a) screening is needed.
Abstract 16161: Effects of Year Long Aerobic Exercise on Left Atrial Size in Patients With Left Ventricular Hypertrophy
Authors: Kyrouac Douglas , Hieda Michinari , Macnamara James P , Hearon Christopher , Levine Benjamin D , Sarma Satyam
Published: December 2023

Introduction:
Habitual aerobic exercise is associated with left atrial (LA) enlargement and risk of atrial fibrillation. This risk may be accentuated in patients with increased left ventricular (LV) stiffness due to high LA pressure during exercise. We tested the hypothesis that 1 year long endurance exercise would increase LA size to a greater extent in patients with left ventricular hypertrophy (LVH) at risk for heart failure with preserved ejection fraction (HFpEF) than previously published age appropriate controls.

Methods:
Middle-aged adults (age 45-64 yrs) with LVH (n=53) enriched for increased HFpEF risk (N-terminal pro-B-type natriuretic peptide >40 pg/mL or high-sensitivity cardiac troponin T >0.6 pg/mL) and healthy subjects (n=58) were randomized to one year of high intensity aerobic exercise or yoga control. LA and LV volumes were measured using 3D echo.

Results:
Of 111 participants, 83 had complete data available (LVH cohort: 18 exercisers, 10 yoga; healthy cohort: 29 exercisers, 26 yoga). Baseline LA size was larger in LVH vs healthy subjects (42 ± 12 vs 35 ± 9 mL; p=0.005). There was a nominal increase in LA size in LVH exercisers compared to LVH yoga (8 ± 9 vs 4 ± 7 mL; p=0.29) which was proportional to LV size (LA/LV ratio 0.05 ± 0.07 vs 0.06 ± 0.1; p=0.81). Healthy subject exercisers increased LA size compared to healthy yoga controls (4 ± 5 vs 0 ± 6 mL; p=0.02) with no increase in LA/LV ratio (-0.02 ± 0.08 vs -0.03 ± 0.08; p=0.62). Among exercising subjects only, increase in LA size was larger in LVH compared to healthy subjects after year long aerobic training (p=0.04) with greater increase LA/LV ratio (p<0.001).

Conclusions:
One year of aerobic training resulted in higher LA size in patients with at-risk LVH compared to healthy subjects. The increase in LA size was greater than changes in LV size suggesting chronic aerobic training may preferentially affect LA remodeling.
Abstract 16164: Lipoprotein (a) Testing in Patients With Atherosclerotic Cardiovascular Disease in Five Large U.S. Health Systems
Authors: Shah Nishant P , Mulder Hillary , Lydon Betsy , Chiswell Karen , Lampron Zachary , Cohen Lauren , Hernandez Adrian F , Patel Manesh R , Taubes Susan , Song Wenliang , Mulukutla Suresh R , Saeed Anum , Morin Daniel P , Bradley Steven M , Hu Xingdi , Pagidipati Neha J
Published: December 2023

Introduction:
Lipoprotein (a) [Lp(a)] is an independent, causal risk factor for atherosclerotic cardiovascular disease (ASCVD). Screening patterns remain variable and it is unclear what factors are associated with Lp(a) testing, and whether knowing the Lp(a) value changes management.

Research Question:
To better understand the proportion of Lp(a) testing, factors predicting Lp(a) testing, and impact on management in ASCVD patients.

Methods:
A retrospective study using electronic medical record data from five health systems in the CardioHealth Alliance and PCORnet® identified a cohort with an ASCVD diagnosis in 5 years prior to the index date. The index date was defined as the date of the first Lp(a) test result in 2019-2021 for those with a Lp(a) test, or the date of a randomly selected outpatient encounter in 2019-2021 for those without a Lp(a) test. Initiation of lipid lowering therapy (LLT) was assessed within 6 months after the index date. Multivariable regression modeling was used to determine factors associated with Lp(a) testing.

Results:
Among 595,685 ASCVD participants, only 2,588 (0.4%) were tested for Lp(a). In adjusted models, those who were older, Black, or Hispanic were less likely to have Lp(a) testing, while those with familial hypercholesterolemia, ischemic stroke/TIA, PAD, prior LLT, or LDL-C ≥130mg/dL were more likely to be tested (table). Those with elevated Lp(a) (>50mg/dL or >125 nmol/L) were more likely to initiate any LLT (43.9% vs 34.6%, p=0.03), particularly PCSK9i (10.9% vs 4.8%, p<0.01) and ezetimibe (11.5% vs 5.9%, p <0.01) compared to those without elevated Lp(a). Statin initiation remained similar between those with and without elevated Lp(a) (32.1% vs 29.5%, p=0.47).

Conclusion:
Lp(a) testing in ASCVD patients is infrequent, with evidence of disparities by race and ethnicity. Having elevated Lp(a) was associated with higher initiation of non-statin LLT. However, overall initiation of any LLT after an elevated Lp(a) test was low.
Abstract 16178: A Deep Learning Algorithm to Estimate Left Ventricular Mass From Coronary Calcium CT Scans: Association With Incident Heart Failure Events From the Dallas Heart Study
Authors: Simek Shawn , Kay Fernando , Abbara, MD Suhny , Ayers Colby , Garg Sonia , Pandey Ambarish , Rohatgi Anand , Khera Amit , Drazner Mark H , Budoff Matthew J , de Lemos James A , Peshock Ronald M , Joshi Parag H
Published: December 2023

Introduction:
Coronary artery calcium CT (CAC-CT) scans used for ASCVD risk prediction may contain additional clinical information that is currently underexploited. We developed a novel deep-learning algorithm to estimate LV mass from CAC-CT (CT-LVM) and analyzed associations with cardiac biomarkers and incident CV outcomes in the Dallas Heart Study (DHS).

Hypothesis:
Higher CT-LVM will be associated with baseline cardiac biomarker elevations (hsTnT and NT-proBNP) and a higher risk of incident CVD (heart failure, MI, stroke, and all-cause death).

Methods:
We included 1841 DHS phase 2 participants (mean age 50, 59% female, 46% Black race) who were free of baseline CVD and underwent CAC-CT and cardiac MRI. Our novel deep-learning algorithm features automatic cardiac chamber segmentation via a 3D U-Net architecture on CAC-CT, followed by a 3D DenseNet model to predict LV mass, using concurrent cardiac MRI as gold standard. LV mass was indexed to BSA. Statistical analysis included multivariable logistic regression models for baseline biomarker elevation assessment (hs-cTnT
>
5ng/L or NT-proBNP
>
100pg/mL) and Cox proportional hazards models for clinical outcomes. Models were adjusted for age, sex, ethnicity, BMI, hypertension, blood pressure, diabetes, smoking, creatinine, and CAC score.

Results:
CT-LVM correlated strongly with MRI defined LV mass (R = 0.87). CT-LVM/BSA was associated with elevated hsTnT (adjusted OR 1.3, 95% CI 1.1-1.6) and NT-proBNP (adjusted OR 1.8, 95% CI 1.5-2.2). There were 172 CVD events over a median follow up of 12.5 years. Higher CT-LVM was associated with higher CVD risk (adjusted HR 1.4, 95% CI 1.2-1.6) and higher risk of incident heart failure (adjusted HR 2.1, 95% CI 1.5-2.9).

Conclusions:
A novel deep-learning method for estimating LV mass from CAC-CT provided independent risk information from traditional risk factors and CAC score. This represents a novel low-cost approach to improving the risk assessment opportunities from a CAC-CT.