Abstract Background Accurate assessment of left ventricular outflow tract (LVOT) gradients is critical for hypertrophic cardiomyopathy (HCM) management, yet Doppler-based measurements are technically demanding and require expertise. Objective To develop a multi-view deep learning model capable of classifying LVOT obstruction (> 20mmHg) using routine 2D echocardiographic windows without reliance on Doppler imaging. Methods We trained and externally validated a cross-attention-based video-to-video fusion framework that integrated EchoPrime-derived video representations from three standard transthoracic echocardiographic views to classify LVOT gradients. Results Training was performed on a derivation cohort (N = 1833) from a tertiary care system in the United States, with model performance evaluated on an internal held-out test set (N = 275) and a Korean external validation cohort (N = 46). Single-view baselines showed limited discrimination (external AUROCs 0.47–0.70). Conversely, domain-specific foundational model (EchoPrime) achieved superior single-view performance (AUROCs 0.75–0.80 internal; 0.79–0.83 external), highlighting the importance of echo-specific pretraining and temporal modeling. The proposed multi-view fusion further enhanced predictive performance, with the late fusion model reaching an AUROC of 0.84 on the external cohort with significant population-shift. Conclusions These results suggest LVOT physiology is encoded in routine 2D imaging and can be leveraged for clinically relevant gradient classification without Doppler input- proposed AI-guided strategy demonstrates substantial cost savings compared with the screen-all approach. By integrating complementary spatial-temporal information across multiple views, our approach generalizes robustly across populations and may enable real-time decision support, extend LVOT assessment to portable or resource-limited settings, and complement Doppler-based evaluation for longitudinal HCM management.
Prognostic value of transaortic flow rate compared with ejection fraction and stroke volume index in low-gradient severe aortic stenosis
Background In low-gradient severe aortic stenosis (AS), reduced left ventricular ejection fraction (LVEF <50%) is practically used to define low flow and prompt dobutamine stress echocardiography to discern pseudo-severe AS. In patients with preserved LVEF, stroke volume index (SVI) <35 mL/m² is typically used. However, both are volume-based surrogates. Transaortic flow rate (TAFR), calculated as stroke volume divided by left ventricular ejection time, may better reflect true flow. Nonetheless, comparative data between TAFR and established metrics remain limited. We aimed to evaluate the prognostic value of TAFR in symptomatic low-gradient severe AS. Methods We retrospectively identified patients with low-gradient severe AS (AVA ≤1 cm 2 and peak velocity (Vmax) <4 m/s or mean gradient (MG) <40 mm Hg) who underwent transcatheter aortic valve replacement at Mayo Clinic sites (2017–2023). The primary outcome was 1-year all-cause mortality. Survival was assessed using Kaplan-Meier and Cox proportional hazards models. Results Among 475 patients included (mean age 85±8 years; 49% women), 242 (51%) had TAFR <220 mL/s, 165 (35%) had EF <50%, and 221 (47%) had SVI <35 mL/m 2 . Low TAFR was significantly associated with higher 1-year mortality even after stratifying by EF or SVI. In multivariate analysis, TAFR was an independent predictor of mortality (HR 2.38; 95% CI 1.19 to 4.76, p=0.014) after adjusting for reduced LVEF, low SVI, gender, chronic kidney disease and mitral and tricuspid regurgitation. Conclusions In patients with symptomatic low-gradient severe AS, low TAFR, not SVI or LVEF, is independently associated with mortality and may offer more accurate measure of flow state for clinical staging.
Abstract 2597: Baseline cfDNA fragmentomics identifies multiple myeloma patients at risk of early progression
Abstract Introduction: Early relapse limits durable remissions in multiple myeloma (MM). Cell-free DNA (cfDNA) fragment patterns capture tumor burden and nucleosome positioning. We tested whether a fragmentomics signature trained at MRD time points stratifies progression-free survival (PFS) when applied to pretreatment plasma. Methods: We performed 30-40× whole-genome sequencing of plasma cfDNA from 43 newly diagnosed MM patients, with 65 additional MRD timepoint samples from 41 of those patients (post-ASCT n=30; 1-year maintenance n=30; other maintenance n=5) across eight Canadian sites (TFRIM4 and IMMAGINE studies) and one U.S. site (Mayo SPORE). MRD testing used multiparameter flow cytometry for all follow-up samples (n=65) and clonoSEQ in a subset (n=31). Logistic and elastic-net models were trained at MRD timepoints on fragmentomics features (short-fragment burden; a combined model integrating fragment-length distributions with inferred nucleosome positioning at MM-specific chromatin accessibility regions [Ordoñez et al., Genome Res. 2020]). A decision threshold was fixed by the Youden index during training and applied unchanged to diagnosis samples. PFS was analyzed by Kaplan-Meier, log-rank, and Cox models. Results: After a median follow-up of 49.1 months, 16 of 43 patients (37%) progressed. Using the prespecified locked threshold, patients classified as MRD+ by the proportion-of-short-fragments model had significantly shorter PFS than MRD- patients (HR = 5.12; 95% CI 1.16-22.57; log-rank p = 0.016), with median PFS of 49.2 months for MRD+ cases versus not reached for the MRD- group. Fixed-horizon PFS favored MRD- samples at 24/36/48 months (100/94/87% vs 85/81/53% for MRD+). A combined model integrating weighted fragment lengths with inferred nucleosome positioning also separated outcomes (log-rank p=0.054); the Cox HR was not estimable because no MRD- patients relapsed. At 24, 36, and 48 months, baseline MRD positivity by the short-fragment model identified 100%, 83%, and 86% of patients who relapsed within those intervals (specificity 44%, 43%, and 52%), while the combined model detected all early relapses across the same horizons (specificity 15-21%), indicating consistently high sensitivity but modest specificity for predicting early progression. Conclusions: A cfDNA fragmentomics signature trained at MRD time points stratified PFS when applied to diagnostic plasma, identifying patients at risk of early relapse. Short-fragment burden was most discriminative, and a combined model with nucleosome positioning recapitulated it with higher sensitivity, albeit lower specificity. These data support cfDNA fragmentomics as a practical liquid-biopsy risk biomarker in MM and suggest higher signals may proxy aggressive disease with greater tumor shedding and chromatin disorganization. Future work will validate findings in larger cohorts and integrate cytogenetic and immune features. Citation Format: Dor David Abelman, Jenna Eagles, Aimee Wong, Saumil Shah, Jeffrey Bruce, Stephanie Pedersen, David S. Scott, Cecilia Bonolo de Campos, Signy Chow, Darrell White, Irwindeed Sandhu, Kevin Song, Esteban Braggio, Shaji Kunnathu Kumar, Alli Murugesan, Tony Reiman, A. Keith Stewart, Suzanne Trudel, Trevor J. Pugh. Baseline cfDNA fragmentomics identifies multiple myeloma patients at risk of early progression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 2597.
Abstract 985: Anticancer efficacy of tricarbonylperrhenato(bathophen)rhenium(I) organometallic compound in pancreatic ductal adenocarcinoma
Abstract Organometallic rhenium compounds have become powerful anticancer agents that show possibilities as a substitute for traditional platinum-based medications. While platinum-based chemotherapeutics like FOLFIRINOX and cisplatin are frequently used to treat pancreatic ductal adenocarcinoma (PDAC), they have a number of side effects, such as ototoxicity, neurotoxicity, nephrotoxicity, and peripheral neuropathy. Hepatotoxicity, cardiotoxicity, gastrointestinal toxicity, cytopenias, anaphylaxis, pain, alopecia, anorexia, cachexia, and asthenia are other commonly reported adverse effects. However, ligands based on rhenium have been shown to preferentially cause cytotoxicity in cancer cells while avoiding harm to healthy cells. This suggests that rhenium could be a safer and more effective cancer treatment option. Different rhenium compounds with different ligands have been produced by Mandal et al. for a range of medicinal uses. In this work, we assessed the therapeutic potential of tricarbonylperrhenato(bathophen)rhenium(I) (PR-6) in PDAC. The cytotoxic effects and IC50 value of PR-6 were assessed in the metastatic pancreatic cancer cell line AsPC-1 using the MTS assay. The IC50 value for PR-6 in AsPC-1 cells was determined to be 5.85 µM. PR-6 treatment significantly inhibited cell growth, migration, and survival at the IC50 concentration, with a post-treatment survival rate of 2.3 ± 3.97%. Furthermore, PR-6 treatment led to the downregulation of phosphorylated MEK (pMEK) and phosphorylated P38 (pP38) protein expression, indicating its modulatory effect on the MAPK signaling pathway. According to our research, PR-6 has a great therapeutic promise for treating pancreatic cancer and efficiently alters the tumor microenvironment in PDAC cells. Citation Format: Ishita Saha, Cecilia Parpinelli, Birsen Varisli, Santosh Mandal, Santanu Bhattacharya. Anticancer efficacy of tricarbonylperrhenato(bathophen)rhenium(I) organometallic compound in pancreatic ductal adenocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 985.
Stroke and systemic embolism following atrial fibrillation ablation: the EMBOL-AF Global Registry
Abstract Background and Aims Stroke and systemic embolism are recognized but poorly characterized complications of atrial fibrillation (AF) and left atrial flutter (AFL) catheter ablation. Their incidence, outcomes, and procedural associations remain insufficiently defined. Methods Retrospective global registry was initiated by the European Heart Rhythm Association Scientific Committee. A secure database captured data from ablation centres worldwide on general AF and left AFL ablation activity, as well as detailed information on patients with symptomatic embolic events between 2017 and 2024. Results Overall, 204 centres reported 335 743 ablation procedures and 550 embolic events (incidence 0.16%). Centre-level rate ranged from 0% to 3.1%. Most events were cerebral (94%), followed by peripheral (5%), and combined (1%). Coronary air embolism accounted for 62% of all peripheral events. Intraprocedural events occurred in 93 patients (17%), within 72 h in 357 (78%) and beyond 72 h in 100 (22%); 128 cases (23%) were diagnosed after hospital discharge. Nonparoxysmal AF (0.23% vs 0.15%; P < .001), centre experience, and ablation energy source (radiofrequency, 0.16%; cryoballoon, 0.16%; pulsed field ablation, 0.25%; laserballoon, 0.88%; P < .001) were associated with embolic risk. Median NIHSS score after stroke was 4 (interquartile range, 2–9). Three-month follow-up was available for 518 patients with embolism (95%): 181 (35%) had sequelae and 16 (3%) died. Conclusions Symptomatic embolic events are infrequent but associated with significant morbidity and mortality. Most events occur early, though a substantial proportion arise later. Higher event rates were observed with laser and possibly with pulsed field ablation. A greater centre experience was associated with a lower embolism incidence.
Distinct advantages for risk scoring models in patients with clonal cytopenia of undetermined significance
TP53
Mutations and Circulating Blasts ≥ 20% Are the Primary Determinants of Survival in Accelerated/Blast‐Phase Myeloproliferative Neoplasms Treated With Frontline Venetoclax
ABSTRACT The objective of this study is to describe outcomes of rapid exome (rES) and rapid genome sequencing (rGS) in an inpatient setting. This is a retrospective cohort of inpatients with rES or rGS during their hospitalization between April 2016 and November 2023. Medical records were reviewed to measure primary outcomes: diagnostic yield, medical management changes, and anticipatory guidance updates. Descriptive analysis and formal comparisons (Welch's t ‐test with post hoc power analysis, Fischer's exact test) were performed, with rES and rGS comparisons limited to 2023 due to test distribution. Of 95 patients, most (74.7% [71/95]) were < 12 months old and admitted in neonatal (44.2% [42/95]) or pediatric (29.5% [28/95]) intensive care units. Common indications for rapid sequencing included multiple congenital anomalies (24.2% [23/95]), neurological concerns (23.3% [22/95]), and acute illness (16.8% [16/95]). Mean turnaround time of testing significantly shortened for rES from 2021 (13.2 [SD = 5.9] days) to 2023 (8.1 [SD = 4.1] days) ( p ‐value = 0.018; power = 0.74). Diagnostic yield was 29.5% (28/95) and did not significantly differ between rES (13.6% [3/22]) and rGS (35.0% [7/20]) ( p ‐value = 0.15). Sequencing led to medical management changes (86.0% [74/86]) and anticipatory guidance updates (41.4% [39/95]) with similar rates observed in diagnostic and non‐diagnostic tests. Our findings suggest rES or rGS implementation may influence diagnosis and care strategies in critically ill patients.
Proximity extension assay-based targeted proteomics for biomarker discovery in adult bacterial infections
Background Bacterial infections remain a major global health burden, causing significant morbidity and mortality. Despite ongoing advances, prompt diagnosis is still hampered by nonspecific host biomarkers and the inherently slow turnaround of traditional microbiological cultures. These limitations often delay the initiation of appropriate treatments. In recent years, affinity-based proteomic approaches have been explored to address this gap. Among them, the Proximity Extension Assay (PEA) has emerged as a promising multiplexed protein quantification tool, capable of simultaneously measuring hundreds of immune and inflammatory proteins with high sensitivity from minimal sample volumes. Such technologies hold the potential to identify novel biomarkers, thereby improving both diagnosis and patient management in bacterial infections. Main body In this systematic scoping review, we examined studies applying PEA-based proteomics to adult bacterial infections. Out of the records screened, ten studies met inclusion criteria. Most were conducted in Europe and North America, relied primarily on plasma samples, and employed commercially available panels enriched for immune and inflammatory mediators. Study quality varied, with some evidence of variability and potential risk of bias. Across the 379 proteins investigated, a subset of proteins were consistently associated with bacterial infections across multiple clinical contexts, whereas others showed limited or no associations. Conclusions Current applications of PEA-based proteomics in adult bacterial infections is limited and largely exploratory. Rather than supporting immediate clinical translation, the available evidence suggests the value of PEA-based approaches for informing biomarker discovery. Future research should prioritize well-designed, longitudinal, and pathogen-stratified studies in clinically relevant settings to strengthen evidence robustness and support the rational development of proteomics-informed diagnostic and translational strategies.