Abstract 4112869: Development of a Sitosterolemia Risk Prediction Scale (SRPS): A Screening Tool

Circulation, Volume 150, Issue Suppl_1, Page A4112869-A4112869, November 12, 2024. Introduction:Sitosterolemia, a hereditary disorder marked by elevated plant sterol levels, presents diagnostic challenges due to its similarity to other lipid disorders. The development of the Sitosterolemia Risk Prediction Scale (SRPS) aims to address this by synthesising genetic, clinical, and dietary data into a coherent risk assessment model.Research Question:We propose that a structured risk scale, integrating diverse factors known to affect sitosterolemia, can significantly improve the accuracy of predicting the disorder. The SRPS is hypothesised to facilitate early detection and inform targeted interventions.Aim:The primary aim is to conceptualise and outline the SRPS, which categorises individuals into risk categories based on a point system reflecting genetic predispositions, clinical symptoms, dietary habits, and response to treatments. This scale seeks to enhance the clinical identification of sitosterolemia, promoting timely and personalised management strategies.Methods:A detailed table was generated to present the SRPS, categorising risk factors into genetic, clinical, dietary, and response to treatment. This innovative method allowed for the efficient synthesis and visualisation of complex data.Results:The SRPS table methodically organizes risk factors into low (0-2 points), moderate (3-5 points), and high (6+ points) categories. This stratification guides further diagnostic actions, ranging from exploring alternative causes of hyperlipidemia to necessitating comprehensive genetic and lipid analyses.Conclusion:The SRPS represents an innovative framework for assessing sitosterolemia risk, highlighting the potential benefits of integrating genetic, clinical, and dietary information. It further underscores the importance of a multifactorial approach in the early detection and management of sitosterolemia.

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Novembre 2024

Abstract 4138955: Artificial intelligence-guided screening of rheumatic heart disease from single-view two-dimensional echocardiography

Circulation, Volume 150, Issue Suppl_1, Page A4138955-A4138955, November 12, 2024. Introduction:Rheumatic heart disease (RHD) is the most common acquired heart disorder in children and adolescents worldwide. We developed and validated an automated artificial intelligence (AI)-guided RHD screening algorithm adapted for point-of-care ultrasonography (POCUS) in school-aged children.Methods:We employed a cross-domain transfer learning approach, in which a 3D convolutional neural network (CNN) was first trained to detect structural RHD deformation of the mitral or aortic valves in 244,523 videos, representing all views from 5,614 adult transthoracic echocardiograms (1:5 age and sex-matched cases and controls; median age 69 [58-80] years, 76.4% female) in a large US health system. The model was fine-tuned for stage ≥B (“definite”) RHD in 21,472 POCUS videos (2D parasternal and apical acquisitions) from 5,525 studies (75% training, 25% validation) in a pediatric screening program (median age 11 [IQR 10-13] years, 54.6% female) in Brazilian low-income schools. Testing was performed in a held-out set of 1,966 parasternal long-axis (PLAX) videos from 1,138 studies in Brazil (14 [1.2%] with stage ≥B RHD) as well as in an external pediatric screening set in Uganda consisting of 249 videos from 96 studies (34 [35.4%] with stage ≥B RHD) (Fig. 1).Results:Our model (Fig. 2) achieved a study-level AUROC (area under the receiver operating characteristic curve) of 0.88 across the held-out/external testing sets for identifying stage ≥B RHD from cardiac POCUS (Fig. 3A). On a video-level the model learned a continuous spectrum of phenotypes on PLAX acquisitions spanning stage ≥B (“definite”) and stage A (“borderline”) cases, ranging from a median video-level AI probability of 0.13 [0.01-0.73] for stage ≥B to 0.00 [0.00-0.01] for non-RHD POCUS (Fig. 3B). At the threshold that maximized Youden’s J in the held-out Brazil set, our algorithm’s performance in the set from Uganda showed 97% recall (sensitivity), a positive predictive value (precision) of 46%, and a negative predictive value of 95%.Conclusions:A transfer learning approach that employs multi-view learning achieves excellent performance for RHD on single-view two-dimensional cardiac POCUS without Doppler. Our study suggests a scalable approach to AI-enabled RHD detection with images that can be acquired by individuals with modest training.

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Novembre 2024

Abstract 4145962: Evaluating a Single-Lead, Mobile Electrocardiogram for Screening of Atrial Fibrillation in Patients with Obstructive Sleep Apnea

Circulation, Volume 150, Issue Suppl_1, Page A4145962-A4145962, November 12, 2024. Introduction:Obstructive sleep apnea (OSA) affects nearly a billion adults worldwide, and is associated with an increased risk of coronary artery disease, heart attack, heart failure, and arrhythmias – notably atrial fibrillation (AF). Low cost, point of care mobile electrocardiograms (MobileECGs) record and detect heart rhythm abnormalities in 30 seconds. This study aims to assess the effectiveness of the KardiaMobile (AliveCor) MobileECG device as an AF screen in the OSA patient population.Methods:The MobileECG Sleep Study enrolled 500 adult University of Florida Health patients in an observational study between March 2021 and March 2024. After providing consent and completing a brief survey regarding pre-existing health conditions and overall sleep health, a trained research assistant performed the AF screening with the KardiaMobile ECG device. ECG readings were marked for previously undetected abnormalities (potential AF, tachycardia, bradycardia, etc.) and statistically analyzed to determine stroke risk using the CHA2DS2-VASc scoring system. CHA2DS2-VASc criteria includes congestive heart failure, hypertension, age ≥75 (doubled), diabetes, stroke (doubled), vascular disease, age 65 to 74 and sex category (female).Results:A total of 500 participants were enrolled over a 3 year period at University of Florida Health Sleep Center. Of which 276 (55.2%) were female and 224 (44.8%) were male, with a mean age of 56.34 (SD 15.74) and a mean weight of 222.50 (SD 63.25). Of those tested, 68 (13.6%) had irregular, previously undetected AF readings. Patients with irregular AF readings using the KardiaMobile ECG device had CHA2DS2-VASc scores of t(68) = 2.15, p = .042, d = 0.26 indicating an intermediate risk for stroke. Oral anticoagulation is recommended for a score of ≥ 2 if the patient has no contraindication. After prior 12-lead ECG data for patients is obtained the determinations will be compared to the KardiaMobile ECG readings using Cohen’s Kappa.Conclusion:MobileECGs offer a rapid, point of care screening tool for AF in an outpatient sleep clinic setting. Early detection of AF in the OSA patient population can result in improved outcomes and reduced instances of stroke events through anticoagulation therapy guided by CHA2DS2-VASc scores. Further research is necessary to understand the long term impact of surveillance AF screening in high risk patient populations on mortality and cost of healthcare.

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Novembre 2024

Abstract 4147650: Right Ventricular Hemodynamics in Patients Screened for HFpEF with a Novel Artificial Intelligence Screening Tool

Circulation, Volume 150, Issue Suppl_1, Page A4147650-A4147650, November 12, 2024. Background:Invasive hemodynamics are the gold standard for diagnosis of heart failure with preserved ejection fraction (HFpEF). A novel, FDA-approved artificial intelligence (AI) technology that uses a single, 4-chamber transthoracic echocardiogram (TTE) image to screen patients for HFpEF shows promise as a non-invasive tool to assist in diagnosis. Development of right ventricular (RV) dysfunction is a sign of a more advanced HFpEF. Advanced RV hemodynamic parameters, beyond pulmonary arterial pressures (PAP), have not been well studied in HFpEF. We sought to correlate advanced RV hemodynamic parameters in patients screened for HFpEF with this AI screening tool.Method:We retrospectively evaluated two cohorts of patients with suspected HFpEF that underwent TTE and RHC at our institution. The most recent TTE for each patient was screened using the AI-based analysis tool and was reported as either “suggestive” or “non-suggestive” of HFpEF – labeled as “positive” or “negative,” respectively. Mean PAP, pulmonary vascular resistance (PVR), pulmonary artery pulsatility index (PAPI), RV cardiac power output (RV-CPO), RV myocardial performance score (RV-MPS), and right atrial pressure to pulmonary capillary wedge pressure ratio (RA:PCWP) were calculated using invasive hemodynamic parameters at rest, and exercise when available. RV-CPO was calculated as [(mean PAP-RAP) x cardiac output] /451, and RV-MPS was calculated as (RV-CPO x PAP)x1.5. Median values were calculated. AI positive and negative groups were compared using Student’s t-test.Results:A total of 47 patients (82% women, 79% Black, average EF 62%) were included, with 23 undergoing subsequent exercise RHC. There were 18 (38%) that screened positive for HFpEF, and 29 (62%) screened negative by TTE AI software. Positive patients had a significantly higher mean PAP (median 31 vs 23 mmHg, p=0.01), PVR (2.1 vs 1.3 WU, p=0.02), and RV-CPO (0.26 vs. 0.17, p=0.04) than patients who were screened negative. There were no significant differences in PAPI, RV-MPS, and RA:PCWP at rest. There were no significant differences in mean PAP, PVR, PAPI RV-CPO, RV-MPS, or RA:PCWP with exercise.Conclusion:Patients screened positive for HFpEF by a novel AI TTE software had significantly higher PAP and RV-CPO at rest, but no differences in PAPI, RV-MPS, or RA:PCWP ratio. This tool may help identify more advanced HFpEF.

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Novembre 2024

Abstract 4139026: Prevalence of Familial Hypercholesteremia (FH) Among Participants in the ACCELERATE Trial: Implications for Opportunistic FH Screening and Prognostication

Circulation, Volume 150, Issue Suppl_1, Page A4139026-A4139026, November 12, 2024. Background:Familial hypercholesteremia (FH) leads to elevated low-density lipoprotein cholesterol (LDL-C) and atherosclerotic cardiovascular disease (ASCVD). Although treatable, FH is underdiagnosed. Lipid lowering therapy may mask diagnostic pretreatment LDL-C levels. Participants of ASCVD trials may be enriched for FH, so ASCVD trial enrollment may be a unique contact point to opportunistically diagnose FH.Hypothesis:The population of the ACCELERATE trial of evacetrapib and ASCVD outcomes is enriched for FH.Methods:ACCELERATE is a phase 3 cardiovascular outcomes trial which randomized 12,092 patients with high-risk vascular disease to receive evacetrapib or placebo. FH was not reported. Using participant-level data, we estimated pretreatment LDL-c using validated corrections based on type and dose of statin therapy. We defined severe hypercholesterolemia as pretreatment LDL-C ≥ 190 mg/dl and FH as severe hypercholesterolemia with total cholesterol > 290 mg/dL in a first or second degree relative, consistent with Simon Broome register criteria. We compared trial prevalence to general prevalence (severe hypercholesterolemia ~7%, FH ~0.4%). We evaluated the adjusted association of severe hypercholesterolemia with the primary trial endpoint of ASCVD events using multivariable Cox proportional hazards regression.Results:Data were available for 11,993 participants (99%). The prevalence of severe hypercholesteremia was 15% (1809/11993). The prevalence of FH was 2.1% (255/11993). Pretreatment LDL-C ≥ 190 mg/dL, as compared with pretreatment LDL-C < 190 mg/dL, was significantly associated with a higher incidence of the primary ASCVD trial endpoint (15% vs 13.5% respectively, adjusted hazard ratio 1.19; 95% CI 1.03-1.38, P=0.021;Figure).Conclusion:In a participant-level analysis of a rigorous, independently adjudicated ASCVD outcomes trial, severe hypercholesterolemia and FH were more prevalent in the trial population than the general population based on pretreatment LDL-C calculation. Severe hypercholesterolemia was significantly associated with higher ASCVD incidence. ASCVD trial enrollment may be a novel high-yield contact point for index FH case identification using simple pretreatment LDL-C calculation.

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Novembre 2024

Abstract 4137770: Development of a User-Friendly Self-Screening Tool for Assessing Metabolic Syndrome Risk in young adults from economically challenged regions

Circulation, Volume 150, Issue Suppl_1, Page A4137770-A4137770, November 12, 2024. Background:Metabolic syndrome is a cluster of conditions that increase the risk of heart disease and diabetes. Early identification and management are crucial, particularly in economically challenged regions where access to healthcare may be limited.Research Questions/Hypothesis:User-friendly self-report data accurately predict metabolic outcomes.Aims:To develop and validate nomograms for individualized estimation of metabolic syndrome risk.Methods:Data from 521 college students (60.1% aged 17-20 years; 68.7% female; 28.0% white) were collected in 2022/2023 from two Brazilian cities. These cities are located in the country’s poorest states, with Gini indices of 0.56 and 0.43. The potential predictors include demographic and economic variables, school-related factors, behaviors, and body weight. Based on predictors for abdominal obesity identified through multilevel logistic regression, we created a nomogram model. We performed the Hosmer-Lemeshow test to assess model calibration and used a bootstrapping approach (B = 150) for internal validation. To evaluate external validity, we assessed metabolic syndrome in a subset of 375 students. The area under the receiver operating characteristic curve (AUROC), with a threshold of 0.70, was used to evaluate the model’s discrimination accuracy.Results:We identified 114 (23.0%) college students who were abdominally obese. We found ten variables associated with the primary outcome: age, biological sex, physical education facilities, enrollment in sports competition (during elementary school); grade retention, preferred subject, physical education classes per week; enrollment in sports training (during secondary school); adherence of 24-hour movement behaviors and body weight. The proposed nomogram showed acceptable performance in the AUROC (0.94 [95% CI: 0.92-0.96). The calibration assessment indicated reasonable consistency of our model (p > 0.05). In the internal validation, we observed a decreased predictive capability (AUROC = 0.86).Conclusion:The 24h-MESYN risk score offers an effective self-screening tool for college students from diverse racial and ethnic backgrounds in economically challenged regions to assess their risk of developing metabolic syndrome.

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Novembre 2024

Abstract 4143538: A Predictive Tool and Diagnostic Screening Algorithm for the Identification of Transthyretin Amyloid Cardiomyopathy in High-Risk Patient Populations

Circulation, Volume 150, Issue Suppl_1, Page A4143538-A4143538, November 12, 2024. Introduction:Transthyretin amyloid cardiomyopathy (ATTR-CM) is an underdiagnosed disease that may result in heart failure (HF), arrhythmias, and valvular disease. Our aim was to develop (1) screening criteria to identify high-risk patients for ATTR-CM and (2) our own predictive tool of ATTR-CM.Methods:This was a prospective observational registry at 2 academic sites in Canada. We designed screening criteria to identify high-risk patients in HF, atrial fibrillation, transcatheter valve clinics, and in cardiologist’s offices from January 2019-December 2022. Patients >60 years were included if one of several screening criteria was met and they were referred for pyrophosphate scan by the cardiologist. Univariate and multivariate logistic regression were used to identify predictive clinical, imaging, and biochemical characteristics.Results:In total, 2500 patients were screened, and 200 patients were enrolled with a follow-up duration of 3 years. The mean age was 78 years and 65% were male. Forty-six (23%) had a diagnosis of ATTR-CM and 7 (4%) were diagnosed with AL-amyloidosis. ATTR-CM patients were older (83±7 vs. 77±8; p

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Novembre 2024

Abstract 4141994: Targeted Atrial Fibrillation Screening in Older Adults: A Secondary Analysis of the VITAL-AF Trial

Circulation, Volume 150, Issue Suppl_1, Page A4141994-A4141994, November 12, 2024. Background:Screening trials for atrial fibrillation (AF) have produced mixed results; however, it is unclear if there is a subset of individuals for whom screening would be effective. Identifying such a subgroup would support targeted screening.Methods:We conducted a secondary analysis of VITAL-AF (NCT03515057), a randomized trial of one-time, single-lead ECG screening during primary care visits. We tested two approaches to identify a subgroup that would benefit from screening (i.e., heterogenous screening effects). First, we use a potential outcomes framework to develop an effect-based model. Specifically, we predicted the likelihood of AF diagnosis under both screening and usual care conditions using LASSO, a penalized regression method. The difference between these probabilities was the predicted screening effect. Second, we used the CHARGE-AF score, a validated AF risk model. We used interaction testing to determine if the observed diagnosis rates in the screening and control arms were statistically different when stratified by decile of the predicted screening effect and predicted AF risk.Results:Baseline characteristics were similar between the screening (n=15187) and usual care (n=15078) groups (mean age 74 years, 59% female). On average, screening did not significantly increase the AF diagnosis rate (2.55 vs. 2.30 per 100 person-years, rate difference 0.24, 95%CI -0.18 to 0.67). Patients in the highest decile of predicted screening efficacy (n=3026, 10%) experienced a large and statistically significant increase in AF diagnosis rates due to screening (6.5 vs. 3.06 per 100 person-years, rate difference 3.45, 95%CI 1.62 to 5.28; interaction p-value 0.038) (Figure 1). In this group, the mean age was 84 years and 68% were female. Participants in the highest decile of AF risk using the CHARGE-AF score did not have a statistically significant increase in AF diagnosis rates due to screening (Figure 2). Predicted screening effectiveness and predicted AF risk were poorly correlated (Spearman coefficient 0.13).Conclusions:One-time screening may increase AF diagnoses in a subgroup of older adults with the largest predicted screening effect. In contrast, predicted AF risk was a poor proxy for predicted screening efficacy. These data caution against the assumption that high AF risk is necessarily correlated with high screening efficacy. Prospective studies are needed to validate whether AF screening is effective in the subgroup identified in this study.

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Novembre 2024

Abstract 4135476: The Cardiomyocyte Hypertrophy Inhibitor RFN-409, Identified by High Throughput Screening Assay, Suppresses Pressure Overload-induced Systolic Dysfunction in Mice by Suppressing p38 Activity

Circulation, Volume 150, Issue Suppl_1, Page A4135476-A4135476, November 12, 2024. Purpose:When the heart is exposed to stresses such as myocardial infarction or hypertension, it undergoes compensatory hypertrophy in response. However, continuation of the stress causes this compensatory mechanism to fail, and eventually systolic dysfunction or decompensated heart failure occur. As the hypertrophy of individual cardiomyocytes has been observed in this process, controlling cardiomyocyte hypertrophy is a potential target the prevention and treatment of heart failure. In this study, we constructed a high throughput screening (HTS) assay using cardiomyocyte hypertrophy as an index parameter. Compounds that inhibit cardiomyocyte hypertrophy were selected from our low molecular compound library.Methods and Results:In the primary screening, cultured rat primary cardiomyocytes were treated with each compound at a final concentration of 1 µM and then stimulated with 30 µM phenylephrine (PE) for 48 hours. These cells were subjected to fluorescent immunostaining with α-actinin, and cardiomyocyte area was measured using an ArrayScan™ system. The hypertrophy inhibition rate (%) of each compound was calculated as [(PE(+) – compound) / (PE(+) – PE(-))] × 100. The compounds with a hypertrophy inhibition rate greater than 50% and less than 150% were selected as hit compounds. In the secondary screening, these hit compounds were evaluated based on the dose-dependency of cardiomyocyte hypertrophy inhibition and the inhibition of the mRNA levels of the cardiac hypertrophy response genes ANF and BNP using real-time PCR. From the 269 low molecular-weight compounds in the original compound library, eight were selected through the primary and secondary screenings. Among them, we focused on Reference Number 409 (RFN-409). Western blotting indicated that RFN-409 inhibited PE-induced p38 activation. Next, we investigated the effect of RFN-409 on heart failure. Eight-week-old male C57 BL/6J mice were subjected to transverse aortic constriction (TAC) surgery and then randomly assigned to intraperitoneal treatment with RFN-409 (3, 10 mg/kg) or vehicle for eight weeks. RFN-409 at 10 mg/kg significantly prevented TAC-induced increase in left ventricular posterior wall thickness and decrease in left ventricular fractional shortening.Discussion:RFN-409 suppressed TAC-induced development of heart failure, at least partially by inhibiting p38 activity. These findings suggest that RFN-409 may be an effective agent for heart failure therapy.

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Novembre 2024

Abstract 4140494: Postpartum linkage to primary care: Does screening for social needs identify those at risk for loss to follow-up?

Circulation, Volume 150, Issue Suppl_1, Page A4140494-A4140494, November 12, 2024. Background:Primary care after pregnancy is recommended, especially for individuals with recent adverse pregnancy outcomes (APOs, such as preeclampsia or gestational diabetes), who are at increased risk for future heart disease. Health-related social needs (HRSNs) are recognized barriers to care, yet their pregnancy-related prevalence and associations with care are unknown. We sought to (1) describe the pregnancy-related prevalence of HRSNs, and (2) assess associations between pregnancy-related HRSNs and subsequent linkage to primary care.Methods:We analyzed electronic health record data for individuals with prenatal care and delivery (2018-2021) at our urban safety-net hospital. HRSNs were assessed via a routine screener, and we summarized individual responses during pregnancy through 6 weeks post partum as: any positive, all negative, or never screened. Postpartum linkage to primary care was defined as a completed primary care visit after 6 weeks through 1 year post partum. We analyzed the prevalence of HRSNs and their associations with linkage to primary care, using adjusted log-linked binomial regression models. In stratified models we assessed for effect modification by APO history and other variables.Results:Of 4941 individuals in our sample, 53% identified as Black non-Hispanic and 21% as Hispanic, 68% were publicly insured, and 93% completed ≥1 HRSN screening. Nearly 1 in 4 screened positive for any HRSN, most often food insecurity (14%) or housing instability (12%), and 53% linked to primary care. Compared with those who screened negative for all HRSNs (n=3491), linkage to primary care was similar among those who screened positive for any HRSNs (n=1079; adjusted risk ratio, aRR 1.04, 95% confidence interval, CI: 0.98-1.10) and lower among those never screened (n=371; aRR 0.77, 95% CI: 0.68-0.86). We found no evidence of effect modification by APO history, race/ethnicity, insurance, language, or Covid-19 pandemic exposure.Conclusions:In this diverse postpartum sample, we identified a 24% prevalence of pregnancy-related HRSNs and 53% subsequent linkage to primary care. Linkage to primary care was not associated with HRSN screening result (positive versus negative) but was significantly negatively associated with being missed by HRSN screening. Further research is needed to better understand HRSN screening practices and who is missed by screening, and to identify modifiable barriers to postpartum primary care especially after APOs.

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Novembre 2024

Abstract 4145524: Artificial Intelligence-Based Screening for Blood Pressure Phenotypes of White-coat and Masked Hypertension in Outpatient Settings

Circulation, Volume 150, Issue Suppl_1, Page A4145524-A4145524, November 12, 2024. Introduction:White-coat hypertension (WCH) and masked hypertension (MH) complicate accurate blood pressure (BP) monitoring. While ambulatory BP monitoring (ABPM) is effective, its high cost and limited availability are significant barriers.Hypothesis:We hypothesized that a machine learning (ML) model using clinical data from a single outpatient visit could accurately predict WCH and MH.Aims:This study aimed to develop and validate ML-based prediction models for WCH and MH using accessible clinical data to improve diagnostic efficiency and accessibility.Methods:We enrolled patients from two hypertension cohorts, after excluding those with incomplete data. Patients were classified by office BP and ABPM readings per American Heart Association guidelines. ML models, including Multi-layer Perceptron (MLP), Support Vector Machine (SVM), and Tabular Prior-Data Fitted Network (Tab-PFN), were developed. Input parameters included demographic data (age, gender, height, weight, smoker), and office BP (OBP) and heart rate measurements. Principal Component Analysis (PCA), kernel PCA (kPCA), or t-distributed stochastic neighbor embedding (t-SNE) were used to improve class separability.Results:The study population comprised 1481 participants with a mean age of 47.6 years (SD 13.6), 65% of whom were male and 20.1% were smokers. OBP measurements showed a mean systolic BP (SBP) of 128.7 mmHg (SD 15.4) and a mean diastolic BP (DBP) of 84.2 mmHg (SD 11.6). ABPM showed a mean 24-hour systolic BP of 122.5 mmHg (SD 11.8) and diastolic BP of 79.3 mmHg (SD 10.1). The inclusion of demographic and OBP data, along with advanced resampling and dimensionality reduction techniques, significantly improved the model’s predictive ability. The final TabPFN model achieved the best performance with recall, precision, F1 score, and accuracy of 0.747, 0.931, 0.829, and 0.807 for WCH, and 0.713, 0.954, 0.816, and 0.907 for MH.Conclusion:Our ML-based model effectively predicts WCH and MH using accessible clinical data, offering a cost-effective alternative before applying ABPM.

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Novembre 2024

Abstract 4141112: Identifying Gaps in Screening&Treatment for Peripheral Artery Disease (Pad): A Survey on Provider Knowledge, Attitudes, and Practices

Circulation, Volume 150, Issue Suppl_1, Page A4141112-A4141112, November 12, 2024. Background:It is estimated that Peripheral Artery Disease (PAD) affects between 8.5 and 12 million Americans and its prevalence among adults over 40 years of age is increasing. PAD disproportionately affects Black Americans who, at any age, are twice as likely to experience PAD as their white counterparts but are less likely to be screened and benefit from early diagnosis and treatment.Research Questions/Hypothesis:Despite the high prevalence of PAD and the importance of early intervention, screening for PAD remains limited and/or underutilized particularly in primary care settings where most cases of PAD can be identified. This study sought to understand provider knowledge of PAD, associated risk factors, treatment, understanding of disparities in PAD and barriers and facilitators of PAD screening. It was hypothesized that limited resources, lack of awareness on the part of providers and patients, limitations of training in vascular medicine, and other issues are contributing to PAD morbidity and mortality, particularly among Black and Hispanic populations.Methods:Because no current PAD survey was found in the literature, a survey for providers to determine their knowledge, attitude, and beliefs about PAD and the importance and process of PAD screening for patients at risk was developed. The survey was administered to CommonSpirit Health providers in Sacramento, CA between December 2023- January 2024. Specialties engaged in the survey (N=145) included primary care, endocrine, nephrology, cardiology and podiatry providers.Results:Response rate was 21%. Of those responding, primary care was the specialty most represented(69%). A total of 65% of respondents identified medical treatment of risk factors as the primary way to treat PAD, 32% rated their knowledge of risk reduction therapies in PAD as below average, and 88% of respondents were either somewhat or not familiar with racial disparities in PAD. 24% of respondents identified the ‘lack of knowledge of PAD management guidelines’ as the most important barrier to their patients with PAD not receiving risk reduction therapies.Conclusions:Initial survey of providers identifies lack of knowledge as a key indicator of PAD screening practices, including knowledge on racial disparities in PAD. These identified gaps can inform targeted interventions to improve screening, early detection and treatment of PAD.

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Novembre 2024

Abstract 4124675: Deep Learning Screening of Cardiac MRIs Uncovers Undiagnosed Hypertrophic Cardiomyopathy in the UK BioBank

Circulation, Volume 150, Issue Suppl_1, Page A4124675-A4124675, November 12, 2024. Introduction:The prevalence of hypertrophic cardiomyopathy (HCM) in the UK Biobank based on ICD-10 codes (.07%) is lower than global estimates of disease prevalence (0.2 – 0.5%). Prior studies using this data have remarked on the limitations of findings given likely underdiagnosis. The availability of cardiac MRI scans on a fraction of the participants offers an opportunity to identify missed diagnoses.Aims:This study seeks to utilize a generalizable deep learning model to detect likely cases of undiagnosed hypertrophic cardiomyopathy from cardiac MRIs in the UK Biobank.Methods:The foundational model was trained on a multi-institutional dataset of 14,073 cardiac MRIs via a self-supervised contrastive learning approach that sought to minimize the divergence between scans and their associated radiology reports. The pre-trained model was fine-tuned to diagnose hypertrophic cardiomyopathy on a distinct cohort of 4,870 MRIs with 368 cases of HCM, achieving an AUC of 0.94. The fine-tuned model was applied to the UK Biobank cardiac MRI dataset to ascertain predicted probabilities of HCM. Cases exceeding a threshold of 95% – correlating to the top 0.5% of cases (expected specificity of 97% and sensitivity of 60%) – were screened in for manual reading. In a blinded fashion, a board-certified radiologist was tasked with diagnosing HCM on a sample of cases composed of high and low predicted probabilities.Results:Of the 43,017 patients with cardiac MRIs, only 9 (.02%) had an ICD diagnosis of HCM. 266 cardiac MRIs were manually reviewed: 216 had greater than 95% predicted probability of HCM; 50 negative controls were randomly selected amongst cases with predicted probability less than 10%. The radiologist concurred with an HCM diagnosis for 115 cases (sensitivity 53%, specificity 98%), 112 of which were previously undiagnosed. The prevalence of hypertension and aortic stenosis did not significantly differ between the cohort of true positives (69.2%) and false positives (76.6%). The corrected prevalence of HCM in the UK BioBank MRI cohort is estimated at 0.28%.Conclusions:The findings of this study illustrate the remarkable ability of a generalizable deep learning model to detect undiagnosed cases of a rare disease process from cardiac MRIs. This is an important milestone that may allow for widespread screening of hypertrophic cardiomyopathy while minimizing demand for radiologist labor, and thereby allow patients to reap the substantial benefits of earlier treatment.

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Novembre 2024

Abstract 4144083: AI-CVD: Artificial Intelligence-Enabled Opportunistic Screening of Coronary Artery Calcium Computed Tomography Scans for Predicting CVD Events and All-Cause Mortality: The Multi-Ethnic Study of Atherosclerosis (MESA)

Circulation, Volume 150, Issue Suppl_1, Page A4144083-A4144083, November 12, 2024. Background:The AI-CVD initiative aims to extract all useful opportunistic screening information from coronary artery calcium (CAC) scans and combines them with traditional risk factors to create a stronger predictor of cardiovascular diseases (CVD). These measurements include cardiac chambers volumes (left atrium (LA), left ventricle (LV), right atrium (RA), right ventricle (RV), and left ventricular mass (LVM)), aortic wall and valvular calcification, aorta and pulmonary artery volumes, torso visceral fat, emphysema score, thoracic bone mineral density, and fatty liver score. We have previously reported that the automated cardiac chambers volumetry component of AI-CVD predicts incident atrial fibrillation (AF), heart failure (HF), and stroke in the Multi-Ethnic Study of Atherosclerosis (MESA). In this report, we examine the contribution of other AI-CVD components for all coronary heart disease (CHD), AF, HF, stroke plus transient ischemic attack (TIA), all-CVD, and all-cause mortality.Methods:We applied AI-CVD to CAC scans of 5830 individuals (52.2% women, age 61.7±10.2 years) without known CVD that were previously obtained for CAC scoring at MESA baseline examination. We used 10-year outcomes data and assessed hazard ratios for AI-CVD components plus CAC score and known CVD risk factors (age, sex, diabetes, smoking, LDL-C, HDL-C, systolic and diastolic blood pressure, hypertension medication). AI-CVD predictors were modeled per standard deviation (SD) increase using Cox proportional hazards regression.Results:Over 10 years of follow-up, 1058 CVD (550 AF, 198 HF, 163 stroke, 389 CHD) and 628 all-cause mortality events accrued with some cases having multiple events. Among AI-CVD components, CAC score and chamber volumes were the strongest predictors of different outcomes. Expectedly, age was the strongest predictor for all outcomes except HF where LV volume and LV mass were stronger predictors than age. Figure 1 shows contribution of each predictor for various outcomes.Conclusion:AI-enabled opportunistic screening of useful information in CAC scans contributes substantially to CVD and total mortality prediction independently of CAC score and CVD risk factors. Further studies are warranted to evaluate the clinical utility of AI-CVD.

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Novembre 2024

Abstract 4143847: CRISPR screening identifies critical factors regulating DNA damage response in human cardiomyocytes under oxidative stress

Circulation, Volume 150, Issue Suppl_1, Page A4143847-A4143847, November 12, 2024. Introduction:Our previous studies have shown that sustained activation of the DNA damage response (DDR) in cardiomyocytes leads to p53/p21 activation and cardiac dysfunction. Although the DDR generally involves molecules in DNA replication and repair pathways, the non-proliferative nature of cardiomyocytes suggests a cardio-specific DDR mechanism. However, our understanding of DDR in cardiomyocytes remains limited. Here, we aim to use CRISPR interference (CRISPRi) knockdown screens to identify genes critically involved in DDR regulation in human cardiomyocytes. We hypothesize that identifying these gene clusters may allow us to develop methods to prevent cardiac dysfunction by suppressing DDR in cardiomyocytes.Methods and Results:We established a human iPS cell line stably expressing dCas9-KRAB, which allows CRISPRi-mediated gene knockdown, and differentiated the cells into cardiomyocytes. The resulting human iPS cell-derived cardiomyocytes (hiPSCMs) showed the achievement of approximately 80% knockdown efficiency after gRNA transfection. We stimulated the hiPSCMs with H2O2and quantitatively evaluated the expression levels of the DDR markers γH2AX and p21 by immunostaining using the Operetta®high content imaging system. The DDR markers showed a significant concentration-dependent increase in response to H2O2administration. For arrayed CRISPRi screening, we constructed a gRNA library targeting 437 DDR-related genes. Using this library, we knocked down each DDR-related gene in hiPSCMs followed by H2O2stimulation. We quantified the expression levels of DDR markers by calculating the fluorescence intensity ratios relative to control after gene knockdown, and standardized them to calculate Z scores for all 437 genes. The screening successfully revealed the differential impact of each gene knockdown on γH2AX and p21 expression. We identified 71 genes that significantly affected their expression (Z-score < -1 or > 1). Mapping these genes to DDR pathways highlighted the differential impact of gene knockdown within the same pathway, and stratified their importance in cardiomyocytes.Conclusions:Arrayed CRISPR screening using hiPSCMs revealed differential functional significance of DDR-related genes in cardiomyocytes, identifying 71 genes of particularly significant importance. These findings provide a critical understanding of the cardio-specific DDR pathway and important clues for establishing an appropriate method to suppress DDR in the failing heart.

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Novembre 2024

Abstract 4137945: A Tuscany regional screening program for juvenile sudden cardiac death in high schools: the JUST project

Circulation, Volume 150, Issue Suppl_1, Page A4137945-A4137945, November 12, 2024. Background:Juvenile sudden cardiac death (SCD) has high impact on the family and society of the victim. While SCD screening programmes are effective in athletes, most (70-80%) young non-athletes individuals are not routinely screened.Research question:We hypothesized that a low-cost screening program may early identify subjects at risk of juvenile SCD, even in non-athletes.Goals:To evaluate the prevalence of SCD-related abnormal findings and, ultimately, to test the effectiveness of a screening programme in high schools.Methods:Between April 2023 and June 2024, high school individuals were enrolled in a screening programme in Tuscany (Pisa, Lucca and Livorno), based on a questionnaire investigating family history of juvenile SCD or diseases predisposing to SCD and symptoms (syncope, palpitations, chest pain), and digitally recorded electrocardiograms (ECGs). In case of abnormal findings, second-line investigations locally (echocardiography, Holter ECG monitoring and/or exercise testing) or third-line investigations at Fondazione Monasterio, Pisa, Italy (cardiac MRI, genetics or electrophysiological testing) were planned. Only preliminary results of the first-line screening are hereby reported.Results:We have currently enrolled 872 individuals (age 17.1±1.8 years, 481 [55%] males, 288 [33%] smokers, 102 [11.7%] recreational drugs users, and 645 [74%] non-competitive athletes). At questionnaires, 56 individuals (6.4%) had a family history of SCD, 32 (3.7%) a first-degree relative with cardiomyopathy, and 13 (1.5%) with channelopathy. As for symptoms, 21 participants (2.4%) reported chest pain or 26 (3%) syncope during exertion, while 90 (10.3%) paroxysmal palpitations. At ECG, we found 2 cases (0.2%) with a type-2 Brugada pattern, 1 female case (0.1%) with prolonged QTc interval (QTc 480 ms), 20 cases (2.3%) with V1-V3 T wave inversion (age > 16 years), 18 cases (2%) of left ventricular hypertrophy (non-athletes), and 4 cases (0.5%) with atypical ventricular ectopy. After the first-line screening, 61 (7%) and 10 (1.2%) individuals were referred to second and third-line investigations, which are currently ongoing.Conclusions:We hereby propose a screening model in high schools that includes specific health questionnaires and digitally recorded ECGs. From preliminary analyses, this approach seems sensitive enough to be tested as a model to favour the early diagnosis of diseased conditions associated with juvenile SCD in the general population.

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Novembre 2024