Citations

Abstract Background Coronary computed tomography angiography (CCTA) is a non-invasive diagnostic modality for assessing coronary artery disease (CAD), with a growing global trend favouring a "CT-first" approach. However, this strategy strains healthcare systems as demand for CCTA increases. Pre-test probability (PTP) models for obstructive CAD are used to optimize the usage of CCTA. However, these models perform inconsistently across different subpopulations and offer limited discriminatory accuracy, with low positive predictive values (PPV). This study aims to enhance the PTP models with explainable artificial intelligence (XAI) on electrocardiogram (ECG) data. Methods Patients who underwent CCTA for suspected CAD with both CAD-Reporting and Data System (CAD-RADS) classification and Coronary Artery Calcium Score (CACS) were included. Obstructive CAD was defined as CAD-RADS 3 or above. Missing values were imputed. The Risk Factor Weighted Clinical Likelihood (RF-CL) model, based on clinical variables (age, sex, symptom type, smoking, hypertension, dyslipidaemia, diabetes, and family history) was computed. Two gradient descent decision tree models, "AI-ECG" and "AI-CAC," were developed for the pilot study. AI-ECG used clinical risk factors and ECG classification as abnormal, borderline or normal, while AI-CAC further incorporated CACS. We used a cutoff value of 15%, reflecting current guidelines. Comparative analysis was performed using area under the curve (AUC) analysis, the DeLong test for statistical comparison, and feature importance using SHAP values. We intend to develop and present a model based on ECG signal data during the conference. Pilot results We identified 6 178 patients who underwent CCTA between 2022 and 2024 at the Cardiology Centers Netherlands (CCN), of which 2 083 were included (mean age 57.4 ± 10.2 years; 48.1% male). Obstructive CAD was found in 413 (19.8%) patients. The RF-CL model was outperformed by both AI-ECG (AUC: 0.69 vs. 0.80, p<0.001) and AI-CACS (AUC: 0.69 vs. 0.90, p<0.001). Sensitivity increased in both AI models, from 0.46 to 0.87 for AI-ECG and to 0.83 for AI-CACS, while PPV improved only in the AI-CACS model (from 0.37 to 0.61). Key predictive features were CACS, age, sex, ECG classification, and family history. Conclusion and Discussion Our pilot study shows that integrating XAI with clinical risk factors and ECG classification enhances PTP estimation for obstructive CAD. Implementing this model can better stratify patients at risk of obstructive CAD, support more focused CCTA use and reduce unnecessary testing. Nonetheless, further external validation is needed to assess model performance in real-world, prospective clinical settings. Additionally, models based on raw ECG signals have the potential to extract more detailed information.Reciever Operating Characteristic CurvesFeature Importance

Abstract Aims Left bundle branch block (LBBB) is associated with mechanical dyssynchrony, heterogeneous perfusion, and adverse left ventricular (LV) remodeling. However, not all patients with LBBB develop cardiomyopathy, and dyssynchrony can occur without conduction defects. The role of microvascular dysfunction remains uncertain. We aimed to assess how mechanical dyssynchrony and perfusion heterogeneity relate to LV remodeling and function in patients with and without LBBB. Methods and results We retrospectively analyzed 233 patients with isolated LBBB and 932 matched controls who underwent PET myocardial perfusion imaging, assessing mechanical dyssynchrony (phase entropy), myocardial blood flow (MBF), coronary vascular resistance (CVR), myocardial flow reserve (MFR), septal-to-lateral MBF ratio (SLR) for perfusion heterogeneity, LV volumes, and ejection fraction (EF). Compared to controls, patients with LBBB had greater dyssynchrony (56% vs. 40%), larger LV volumes, and lower EF (54% vs. 67%) (all p <0.001), and had higher stress CVR (37 vs. 34 mmHg/mL·min⁻¹·g⁻¹), lower stress MBF (2.4 vs. 2.6 mL/min/g), reduced MFR (2.4 vs. 2.6), and lower SLR (0.95 vs. 1.00) (all p <0.05). Among patients with dyssynchrony, SLR<1.0 identified those with more adverse remodeling. In multivariable regression, phase entropy and SLR independently predicted LV volumes and EF, with adverse effects of SLR reduction amplified in LBBB (interaction p <0.01). In the Cox proportional hazards analysis, phase entropy (HR:1.02, p =0.01), MFR (HR:0.62, p <0.001), and LVEF (HR:0.97, p <0.001) were independently associated with mortality and heart failure hospitalization, whereas LBBB was not. Conclusions Mechanical dyssynchrony and perfusion heterogeneity independently predict adverse LV remodeling, irrespective of LBBB. Integrated imaging enhances cardiomyopathy stratification.

Heart failure (HF) remains a major cause of morbidity and mortality worldwide, with its prevalence continuing to rise due to an aging population and the increasing burden of cardiometabolic diseases. Advances in understanding HF pathophysiology—neurohormonal, inflammatory, and metabolic mechanisms—have led to significant improvements in diagnosis and management, emphasizing earlier detection and patient-centered approaches. Novel biomarkers have the potential to enhance risk assessment beyond traditional natriuretic peptides. Imaging advances can enhance structural and functional assessment, enabling more accurate phenotyping, disease characterization, and risk stratification. Recent advances and real-world data have been used to implement and optimize guideline-directed medical therapy (GDMT) for HF to reduce HF hospitalizations and cardiovascular mortality across the spectrum of HF etiologies. Adjunctive therapies are reserved for select patients with persistent symptoms or high-risk features despite optimal GDMT. Device- and transcatheter-based interventions include established and emerging technologies that address persistent symptoms, structural abnormalities, and hemodynamic abnormalities despite optimal GDMT, thereby expanding treatment options for high-risk patients. Collectively, these advancements highlight a paradigm shift toward precise, personalized approaches to HF management, thereby improving long-term outcomes across the spectrum of HF etiologies.

707 Background: Due to insufficient data, therapy for unresectable, locally advanced pancreatic adenocarcinoma (LAPAC) is based on trials in metastatic disease, and outcomes remain poor. TTFields disrupt cancer cell division using alternating low-frequency electric fields delivered externally by a portable device. In the phase 3 PANOVA-3 trial (NCT03377491), TTFields with gemcitabine/nab-paclitaxel (GnP) significantly improved overall survival (OS; HR 0.82) and pain-free survival (HR 0.74) vs GnP in patients with unresectable LAPAC. Methods: In PANOVA-3, patients with newly diagnosed LAPAC were randomized 1:1 to receive GnP with or without concomitant TTFields. Kaplan-Meier methodology was used for time-to-event analyses. Response evaluations were based on RECIST V1.1. OS, pain-free survival, and safety were analyzed post-hoc in subgroups based on sex (male, female), age ( < 65, ≥65 years), and BMI (<25, ≥25 kg/m 2 for efficacy; ≤20, 20–25, 25–30, ≥30 kg/m 2 for safety). Differences between treatment arms were compared using the log-rank test. Results: Efficacy outcomes are shown in the table. TTFields significantly extended pain-free survival in females and patients ≥65 years. Device-related adverse events (AEs) were comparable between sexes, older and younger patients, and across BMI ranges. Some device-related skin adverse events occurred more frequently in females (e.g. dermatitis, 33.1% vs 22.7%; rash 21.8% vs 13.5%, females vs males, respectively); others occurred more often in males (e.g. maculo-papular rash, 9.8% vs 14.2%; erythema, 9% vs 12.1%, females vs males, respectively). Dermatitis and pruritus had a higher incidence in the BMI ≥30 kg/m 2 subgroup (38.5%), whereas patients with BMI <30 kg/m 2 did not show noticeable differences in device-related AEs. Skin irritation (11.5% vs 5.5%) and skin reactions (8.5% vs 2.8%) were more common in patients ≥65 years than patients <65 years. Conclusions: Median OS and pain-free survival in these post-hoc subgroup analyses are generally consistent with the overall analysis, supporting use of TTFields with GnP in unresectable LAPAC. No new safety concerns were noted; observations were consistent with the general PANOVA-3 population. Clinical trial information: NCT03377491 . Survival outcomes for the subgroup analyses. Median OS, months TTFields + GnP GnP P value Age<65 years≥65 years 18.6 (n=113)15.4 (n=172) 16.0 (n=114)12.9 (n=172) 0.2060.061 SexFemaleMale 16.8 (n=138)15.7 (n=147) 14.5 (n=161)13.4 (n=125) 0.1140.145 BMI<25≥25 16.7 (n=166)16.2 (n=117) 14.2 (n=174)14.5 (n=108) 0.1550.105 Median pain-free survival, months Age<65 years≥65 years 16.5 (n=113)13.1 (n=172) 9.2 (n=114)8.3 (n=172) 0.4070.035 SexFemaleMale 16.5 (n=138)15.2 (n=147) 8.3 (n=161)9.3 (n=125) 0.0260.478 BMI<25≥25 16.6 (n=166)14.7 (n=117) 9.1 (n=174)8.3 (n=108) 0.1170.088

Abstract Background Carbapenem-resistant Acinetobacter baumannii (CRAb) is a multi-drug resistant, opportunistic pathogen. Colistin is one of a few remaining treatment options, but resistance exists globally. Methods Between 2017 and 2019, 551 CRAb isolates were collected through the international Study Network of Acinetobacter as a Carbapenem-Resistant Pathogen (SNAP). Demographics, clinical characteristics, mortality, and a desirability of outcome ranking (DOOR) measure combining lack of clinical response, unsuccessful discharge, renal failure, and C. difficile infection, were recorded for each patient. A central laboratory measured colistin minimum inhibitory concentrations (MICs), and each isolate was classified as colistin-intermediate (MIC ≤2µg/mL) or resistant (MIC ≥4µg/mL). All isolates were sequenced on the Illumina platform, and the genomes were used to construct a phylogenetic tree and assess for variants within known colistin resistance-related genes. Results 18% of the 551 isolates were colistin-resistant. Compared to patients with colistin-intermediate isolates, patients with resistant strains were more likely to have been admitted from a healthcare facility, but otherwise had similar demographics and Charlson comorbidity indices. Focusing on patients with bloodstream or respiratory infections (n=217) uncovered increased 30-day mortality in patients with monomicrobial, colistin-resistant infections (11/19, p=0.008) when compared to monomicrobial-intermediate (41/102), polymicrobial-resistant (4/20) and polymicrobial-intermediate infections (18/76). Comparative genomics indicated that the majority of isolates belonged to clonal complex 2 (CC2), and that colistin resistance concentrated in certain genetic lineages. Variant analysis uncovered nonsynonymous mutations near and within the histidine kinase domain of pmrB, part of the PmrAB two-component system that regulates lipopolysaccharide modifications which can alter colistin susceptibility. Conclusion In this global cohort, patients with monomicrobial, colistin-resistant CRAb infections had increased mortality. New treatment options are needed for multidrug-resistant CRAb, and this study provides further evidence that pmrB may serve as a worthwhile drug development target. Disclosures Madison Stellfox, MD, PhD, Cumberland Pharmaceuticals: Grant/Research Support Robin Patel, MD, a patent on Bordetella pertussis/parapertussis PCR issued, a patent on a device/method for sonication, a patent on PET imaging of bacterial infection: a patent on Bordetella pertussis/parapertussis PCR issued, a patent on a device/method for sonication, a patent on PET imaging of bacterial infection|MicuRx Pharmaceuticals and bioMérieux: Grant/Research Support|PhAST, Day Zero Diagnostics, DEEPULL DIAGNOSTICS, S.L., Nostics, HealthTrackRx, bioMérieux and CARB-X: Advisor/Consultant|Up-to-Date and the Infectious Diseases Board Review Course: Honoraria David van Duin, MD, PhD, British Society for Antimicrobial Chemotherapy: Editor stipend|Merck: Advisor/Consultant|Merck: Grant/Research Support|Pfizer: Advisor/Consultant|Roche: Advisor/Consultant|Shionogi: Advisor/Consultant Yohei Doi, MD, PHD, GSK: Advisor/Consultant|Meiji Seika Pharma: Advisor/Consultant|Shionogi: Advisor/Consultant|Shionogi: Honoraria

Abstract Background Fecal microbiota, live-jslm (RBL) is FDA-approved for prevention of recurrent Clostridioides difficile infection (rCDI) in adults following completion of antibiotic treatment. The safety and efficacy of RBL have been demonstrated in trials, but few studies have evaluated outcomes in real-world populations. The primary objective of ROAR (NCT05835219) is to assess RBL effectiveness in reducing rCDI through 8 weeks in clinical practice. Table 1. Treatment success rates by subgroup Methods ROAR is an ongoing, prospective, multicenter, open-label, non-interventional registry of patients receiving RBL for rCDI prevention in the United States. Adults who completed antibiotics for rCDI and are not in an interventional trial are eligible. The primary endpoint assesses the proportion of patients who experience treatment success (no CDI recurrence through 8 weeks). Other objectives describe rCDI management in real-world clinical practice and adverse events (AEs) after RBL administration. This analysis includes patients who received RBL within 30 days of completing antibiotics for rCDI. Results As of September 18, 2024, 76 patients received RBL within 30 days of completing antibiotics and completed 8 weeks of follow-up. Patients were mostly White (93.4%) and female (76.3%), with a median age of 69 years (range, 19-96 years) and a median body mass index of 24.4 (range, 16.5-49.4). Through 8 weeks, 82.9% of patients (63/76; 95% CI, 72.5%-90.6%) experienced treatment success. Similarly, the rate of treatment success was 87.8% (36/41) in the subgroup of patients who received RBL after an antibiotic washout period &gt; 72 hours. Treatment success rates ranged from 77-100% across patient subgroups, including those stratified by age and number of previous CDI episodes within the past 3 years (Table). Overall, 18 (23.7%) patients experienced an AE, 6 (7.9%) experienced a serious AE, and 1 (1.3%) experienced an AE of special interest (large bowel obstruction). AEs assessed as related to RBL occurred in 3 patients (3.9%). There was 1 fatal AE during the study, considered unrelated to RBL. Conclusion Initial results from ROAR are consistent with previous RBL trial results, indicating that RBL is effective and safe for preventing rCDI through 8 weeks after administration in real-world practice. Disclosures Nicholas W. Van Hise, PharmD, Ferring: Advisor/Consultant|Ferring: Grant/Research Support|Innoviva: Advisor/Consultant Teena Chopra, MD, MPH, Cepheid: Advisor/Consultant|Ferring Pharmaceuticals, Inc: Advisor/Consultant|Melinta: Speaker|Pfizer: Advisor/Consultant|Pfizer: Speaker|Shinogi: Speaker Kelly R. Reveles, PharmD, PhD, AstraZeneca: Advisor/Consultant|Ferring Pharmaceuticals: Advisor/Consultant Sahil Khanna, MBBS, MS, Ferring Pharmaceuticals, Inc: Grant/Research Support|ProbioTech Inc: Advisor/Consultant|Rise: Advisor/Consultant|Takeda: Advisor/Consultant|Vedanta: Grant/Research Support Lasse Nielsen, MS, Ferring: Employee Lorien E. Urban, PhD, Ferring Pharmaceuticals Inc: Employee

Abstract Background Ten years after the original publication, the Centiloid framework is now broadly used to harmonize amyloid‐PET quantification, facilitate data sharing and comparison across cohorts, and even assist visual interpretation in clinical settings. We evaluated the global implementation of Centiloids by comparing their distribution and corresponding positivity thresholds across cohorts. Methods We gathered data from publicly available cohorts and reached out to investigators across the world to collect cross‐sectional Centiloids, demographic and clinical information, and visual read data. Gaussian mixture models (GMM, k=2) were fitted to Centiloid values for each cohort and cutoffs were calculated as mean + 2SD of the lower Gaussian. When visual reads were available, we determined Centiloid cutoffs that maximized correspondence with visual reads (Cohen's kappa). Data was combined across cohorts using random effects meta‐analyses. Results As of January 2025, we included 37 cohorts ( n = 41,678 participants) with heterogeneous pipelines, radiotracers, and clinical and demographic characteristics (Table‐1). The low Gaussian peaks ranged from ‐9 to 10CL; the meta‐analysis identified a common peak at 1CL. The second peaks were more heterogeneous (range=38‐102CL; meta‐analysis outcome=64CL). Across cohorts, the proportion of cognitively unimpaired versus impaired participants impacted the position of both peaks, with better separation in cohorts enriched in impaired individuals (Figure 1C). The meta‐analysis indicated a GMM‐based cutoff of 19CL (95%CI: 16‐21CL, Figure 1B); subgroup analyses showed no evidence of significant effect between single versus multicenter settings (17 versus 20CL, p = 0.30), MRI‐based or PET‐only processing (18 versus 19CL, p = 0.88), and no evidence of difference across radiotracers (Flutemetamol: 16CL; PIB: 17CL, Flutafuranol: 18CL, Florbetaben: 19CL, Florbetapir: 20CL, p = 0.78). In a subset of 29,496 participants with visual reads available, binary visual reads corresponded well to Centiloids (common kappa=0.86, Figure 2A). The visual read‐based cutoff of 24CL (95%CI: 21‐27CL, Figure 2B) maximized correspondence between visual read and quantification and was slightly higher than the GMM‐based cutoff. All meta‐analysis models showed high non‐random heterogeneity (I 2 >80%) across studies, suggesting non‐random differences in peaks and cutoffs. Conclusions Meta‐analysis‐based cutoffs align well with thresholds from the existing literature. High heterogeneity among studies underscores the need to investigate contributing factors, raising concerns about applying common cutoffs.

Abstract Background Sex, education and race/ethnicity are all associated with risk of Alzheimer's disease dementia. Here, we assess the effects of self‐reported sex, educational attainment and race/ethnicity on amyloid‐positivity, and tau‐PET‐positivity in 12,048 (7,394 cognitively unimpaired [CU], 2,177 MCI, and 2,477 dementia) individuals from 42 cohorts worldwide. Method Logistic generalized estimating equations were used to estimate frequency of amyloid‐positivity (using cohort‐specific thresholds for amyloid‐PET [84%] or CSF) and tau‐PET‐positivity (cohort‐specific thresholds of 2SD above mean temporal uptake in amyloid‐negative controls). We assessed: i) sex and APOEε4 ( N = 10,098) associations, to complement earlier findings of a higher frequency of tau‐positivity in females, ii) effects of lower/higher education ( N = 10,970; cohort‐specific median‐split), and iii) effects of race/ethnicity (non‐Hispanic White [hereafter: White], N = 4880; Asian, N = 116; Black or African‐American [hereafter: Black], N = 353; Hispanic, N = 356, only from Northern‐American cohorts). Outcomes were frequency of amyloid‐positivity in CU individuals only, and tau‐PET‐positivity in both amyloid‐positive (AB+) CU and cognitively impaired (CI, i.e. MCI and dementia) individuals. Interaction effects on the relationship between age and amyloid/tau‐positivity were assessed and only retained in the models when significant. Result Female sex was associated with an APOEε4 ‐independent increased frequency of amyloid‐positivity (β=0.51[0.22], p = 0.02) in CU and increase of tau‐positivity in both AB+CU (β=0.27[0.08]) and AB+CI (β=0.37[0.08], both p <0.01). Remarkably, tau‐positivity frequencies of female APOEε4 non‐carriers were equivalent to male APOEε4 carriers in AB+CI (Figure 1). No significant sex* APOE interactions were observed. In CU, higher education was associated with lower amyloid‐positivity frequency (β=‐0.12[0.05], p = 0.02). In contrast, among AB+CU, there was an age*education interaction effect that indicated more pronounced age effects on tau‐positivity in individuals with higher education (age*education:β interaction =0.03[0.01], p <0.01). There were no education effects in AB+CI (Figure 2). In CU, an age*race/ethnicity interaction effect was observed across all non‐White groups compared to White (Hispanic:β interaction =‐0.05[0.01], p <0.01; Black:‐0.04[0.01], p <0.01; Asian:‐0.02[0.01], p = 0.04). This suggests that the impact of age on amyloid‐positivity was less pronounced in non‐White groups. Furthermore, in AB+CI, Hispanic ethnicity was related to higher tau‐positivity frequency than White (β=0.51[0.22], p = 0.02; Figure 3). Conclusion In this multi‐center initiative comprised of clinical and community‐based cohorts, we observed that self‐reported sex, educational attainment and race/ethnicity were related to positivity‐frequencies of Alzheimer's disease pathology.

Objective: The Society of Critical Care Medicine PICU Liberation ABCDEF (A–F) Campaign Collaborative aimed to implement best practices for analgesia (A), breathing (B), comfort/consciousness (C), delirium (D), early mobilization (E), and family engagement and empowerment (F). Our post hoc study of Mayo Clinic data sought to compare the pre-implementation rounding process, which used a nursing script organized by organ systems, with a novel, liberation-focused rounding process emphasizing A–F bundle elements. Design: Secondary analysis of pre- vs. post-implementation surveys collected by independent observers during rounds. Setting: Medical/surgical PICU in a quaternary-care, academic medical center during April to July 2017. Subjects: The observed participants included PICU physicians, nurses, respiratory therapists, pharmacists, and dietitians. Interventions: None. Measurements and Main Results: Survey responses from 145 team members pre-implementation and 67 post-implementation showed improved team satisfaction, communication, and understanding of daily plans (all p < 0.05). Respondents reported an increased frequency of discussions on bundle components A–E (all p < 0.01). Observations of 41 pre-implementation and 46 post-implementation rounds showed an increase in the frequency of discussion of all components of the bundle (all p < 0.01). However, this finding was not at the expense of increased duration of individual rounds since we failed to find a difference in pre- vs. post-implementation duration per patient (480 vs. 544 s per patient, p = 0.20). Conclusions: In 2017, around the time of introducing the nurse-led PICU Liberation rounding process to our practice, we found that after implementation, there was an associated increase in discussions about bundle elements and improved communications and satisfaction in team members.

Objectives: To identify factors associated with short-term mortality among patients receiving microaxial flow pump (mAFP) therapy for acute myocardial infarction-related cardiogenic shock (AMI-CS). Data Sources: We searched four databases (MEDLINE, Embase, CENTRAL, and Scopus) from January 1, 2004, to January 1, 2025. Study Selection: We selected English-language studies that included adults with AMI-CS receiving mAFP and evaluated factors associated with short-term mortality. We excluded patients receiving concurrent venoarterial extracorporeal membrane oxygenation, as well as studies that solely included patients presenting with out-of-hospital cardiac arrest. Data Extraction: Two authors performed citation screening and data extraction. For each factor evaluated in at least two studies, we performed meta-analyses of adjusted odds ratios (aORs) using a random-effects model. Risk of bias was evaluated using the Quality in Prognosis Studies tool, and the certainty of evidence was evaluated using Grading of Recommendations, Assessment, Development, and Evaluations methodology. Data Synthesis: Our primary analysis included 18 studies, encompassing 20,617 patients. Median short-term mortality across studies was 50.7% (interquartile range 38.4–55.3%). Factors associated with short-term mortality based on high-certainty evidence included: increased age (aOR, 1.04 per year [95% CI, 1.03–1.05 per year] or ≥ 65 yr (aOR, 2.42 yr [95% CI, 0.77–7.64 yr]), female sex (aOR, 1.26 [95% CI, 1.09–1.45]), higher body mass index (aOR, 1.05 per point [95% CI, 1.04–1.07 per point]), higher heart rate (aOR, 1.02 per beats/min [95% CI, 1.01–1.02 per beats/min]), higher serum creatinine (aOR, 1.35 per mg/dL [95% CI, 1.08–1.70 per mg/dL]), mechanical ventilation (aOR, 2.53 [95% CI, 1.82–3.53]), vasopressors (aOR, 1.52 [95% CI, 1.11–2.08] for any vasopressors and aOR, 1.37 [95% CI, 1.18–1.58] per each vasopressor), presentation with ST-elevation myocardial infarction (aOR, 1.59 [95% CI, 1.11–2.26]), cardiac arrest (aOR, 2.85 [95% CI, 2.22–3.64]), and hypoxic-ischemic brain injury (aOR, 5.36 [95% CI, 3.03–9.47]). Conclusions: We identified several prognostic factors associated with short-term mortality in AMI-CS patients receiving mAFP support. This work may help inform clinicians, patients, and families regarding utilization of mAFP in AMI-CS.