Citations

Abstract Introduction Hepatopulmonary syndrome (HPS) is a rare condition where liver disease causes intrapulmonary vascular dilation, subsequently leading to intrapulmonary shunting and thus hypoxemia. Although diagnosis can be challenging, classical HPS features include dyspnea, platypnea, and orthodeoxia, which aid diagnosis. Timely diagnosis of HPS is crucial to provide adequate treatment, which ultimately involves supportive care while awaiting liver transplantation. This is a case of a patient who has a known history of alcoholic cirrhosis who presented to the pulmonology clinic with the chief complaint of progressive dyspnea. Investigations established the diagnosis of HPS, and the patient was referred for liver transplantation. Case A 65-year-old female with a past medical history of significant alcohol use, alcoholic cirrhosis, portal hypertension, recurrent upper gastrointestinal bleeding and a 40-pack-year history. She presented to the pulmonology clinic due to progressive dyspnea on exertion, which she had been experiencing for three years. Furthermore, home pulse oximetry readings were in the 80s, and she denied any cough, orthopnea, or peripheral edema. The patient had a previous echocardiogram with a bubble study, which identified concern for left-to-right shunting. Initially, it was perceived to be intracardiac; however, right heart catheterization was completed, and there was no evidence of an intracardiac shunt. Additionally, pulmonary pressures were normal, favouring intrapulmonary shunting. Physical examination was significant for orthodeoxia with oxygen saturation of 89 percent while upright, and 97 percent while supine, and the patient reported feeling less breathless when lying down. Pulmonary function testing was significant for a substantial reduction in diffusion capacity. Given the constellation of symptoms, including platypnea, orthodeoxia, and evidence of intrapulmonary shunting, with a background history of alcoholic cirrhosis, the patient was diagnosed with HPS and was referred for a liver transplant evaluation. Discussion This case identifies the importance of evaluation for HPS in patients with underlying liver disease and persistent shortness of breath. The constellation of liver disease, hypoxemia, and concern for intrapulmonary vascular dilation were telling for this patient. Currently, there is no medical intervention to cure HPS, and treatment revolves around supportive care and supplemental oxygenation while awaiting liver transplantation. After liver transplantation, patients will often experience improved oxygenation due to the correction of the intrapulmonary vasodilation, which in turn corrects the ventilation-perfusion mismatch. Although early postoperative mortality is slightly higher, long-term survival for HPS patients post-transplant is like that of non—HPS transplant recipients. Therefore, early diagnosis and referral for transplant evaluation are critical to optimize patient outcomes. This abstract is funded by: NONE

Abstract Rationale Alpha1-antitrypsin (AAT; gene name SERPINA1) is a critical antiprotease that protects the lung from neutrophil elastase-mediated injury. AAT deficiency predisposes to emphysema, which is further exacerbated by cigarette smoke (CS) exposure. We previously reported (PMID: 38325750) that a nebulized human platelet-derived exosome product (PEP) attenuated CS-induced emphysema in C57BL/6 mice. Given the presence of AAT protein in these platelet-derived exosomes (identified by proteomics), we hypothesized that PEP nebulization would significantly attenuate both spontaneous and CS-induced emphysema in SERPINA1 knockout (KO) mice. Methods Transgenic SERPINA1 KO C57BL/6 mice (both sexes) exposed to CS (10 cigarettes/day and 5 days/week) for 2 months were then randomized to receive nebulized PEP or 0.9% saline (placebo) twice weekly for 4 additional weeks, with continued CS exposure. PEP was reconstituted in 0.9% saline (22.7mg/mL; ∼3 × 10¹0 vesicles/mL) and administered via pressure- and humidity-controlled nose-only inhalation tower (2.25 mL of PEP or saline over 35 minutes). Lung static compliance (Cst), cutaneous O2 saturation, mean linear intercepts (Lm), and plethysmographic parameters were measured during and after the study. Results Histological analysis of the lung tissue sections revealed that PEP significantly attenuated the CS-induced increase in alveolar size, as determined by measurement of the mean linear intercepts (Lm, p < 0.001). Lung static compliance (Cst), which was increased in CS-exposed mice, was also significantly decreased in the PEP-treated group (p < 0.001) compared to placebo in the male and female combined group. Functional respiratory parameters further supported the protective effect of PEP in this AAT-deficient model. In female mice, PEP nebulization significantly improved several CS-impaired pulmonary function parameters, including minute volume (MV, p = 0.024), the flow at the point 50% of tidal volume is expired (EF50, p = 0.021), Peak Inspiratory Flow (PIF, p = 0.009), Peak Expiratory Flow (PEF, p = 0.018), and O2 saturation (p = 0.035). However, these improvements were not observed in male mice. Conclusions These findings extend prior observations and underscore the therapeutic potential of nebulized AAT-enriched PEP directly to the alveolar region, effectively attenuating injury and improving pulmonary function in AAT deficiency-related emphysema. This abstract is funded by: Department of Defense, Mayo Clinic Funding, The Young and Middle-aged Medical High-end Talents in Chongqing Program

Abstract Rationale Obstructive sleep apnea (OSA) is a highly prevalent disorder characterized by recurrent upper airway collapse during sleep, leading to intermittent hypoxemia, sleep fragmentation, and substantial cardiovascular and neurocognitive morbidity. Continuous positive airway pressure (CPAP) therapy remains the gold standard for management, yet adherence is suboptimal due to discomfort, noise, and device intolerance. This has generated growing interest in pharmacologic alternatives that target upper airway physiology. The combination of atomoxetine, a selective norepinephrine reuptake inhibitor, and oxybutynin, an antimuscarinic agent, has emerged as a promising non-device therapeutic option by enhancing pharyngeal muscle tone and stabilizing ventilatory control. This meta-analysis systematically evaluates the efficacy and safety of atomoxetine plus oxybutynin in adults with OSA who are intolerant to CPAP. Methods A comprehensive search was conducted across PubMed, Embase, Scopus, Web of Science, and Cochrane Central from inception through June 2025. Eligible studies were randomized controlled trials (RCTs) comparing atomoxetine plus oxybutynin with placebo or control therapy in adults diagnosed with OSA. Data were extracted and pooled using Stata version 18.0. Mean differences and relative risks (RR) were calculated for continuous and dichotomous outcomes, respectively. Methodologic quality and risk of bias were assessed using the Cochrane Risk of Bias 2.0 tool. Results Eleven RCTs encompassing 196 adults (141 males, 55 females) were included, with a mean treatment duration of 1.38 days. Compared with control, atomoxetine plus oxybutynin significantly reduced the apnea-hypopnea index (AHI) (mean difference −10.16 events/hour; 95% CI − 20.32 to − 0.01; p = 0.05). Improvements were also observed in oxygen desaturation index (ODI), arousal index, and loop gain, though these did not achieve statistical significance. The treatment group experienced fewer adverse events (RR = 0.66; 95% CI 0.37-0.90; p = 0.01) and no increase in sleep disturbances (RR = 0.87; 95% CI 0.83-1.31). Conclusions Combination therapy with atomoxetine and oxybutynin significantly improves AHI and demonstrates a favorable safety and tolerability profile in adults with OSA who are unable to tolerate CPAP. These findings highlight the therapeutic potential of targeting upper airway muscle tone pharmacologically. Larger, long-term RCTs are warranted to confirm sustained efficacy, determine optimal dosing strategies, and clarify the role of this regimen within the evolving landscape of OSA management. This abstract is funded by: None

Abstract Background Sputum color is a visual marker of airway inflammation and disease activity in bronchiectasis, ranging from clear or light gray (mucoid) to yellow-green (purulent), the latter largely reflecting neutrophil myeloperoxidase release. This study evaluated associations between sputum color and common clinical markers of disease activity to determine which parameters differed most between color categories. Methods Forty spontaneous sputum samples were analyzed from 80 consecutive adults with non-cystic fibrosis bronchiectasis (median age 70 years [IQR 12]; 74% female) enrolled between January 2024 and April 2025 in an observational study. Sputum color was graded using the Murray Sputum Color Chart and classified as mucoid (color #1) or purulent (colors #2-4). Clinical parameters, including blood cell counts, C-reactive protein (CRP), fractional exhaled nitric oxide (FeNO), and results of bacterial and acid-fast bacillus cultures (induced or bronchoscopic), were obtained from medical records if available within one month of enrollment. Categorical variables were analyzed using chi-square or Fisher’s exact tests and continuous variables with the Mann-Whitney U test. A secondary analysis compared patients who could versus could not produce spontaneous sputum. Results Of 40 samples, 20 (50%) were purulent. Blood neutrophil counts (median 4.5 vs. 3.9 x109/L), neutrophil-to-lymphocyte ratios (2.5 vs. 2.6), and eosinophil counts (1.7 vs. 1.7 x109/L) did not differ significantly between groups (n = 26). FeNO was normal in all 10 patients with available data and was not analyzed further. CRP was higher among patients with purulent sputum (4.6 vs. <3 mg/L; n = 20; p = 0.044). Bacterial growth was more frequent in purulent than mucoid samples (73% vs. 31%; n = 31; p = 0.032). Isolates in the purulent group included Klebsiella, Pseudomonas, Staphylococcus, and Streptococcus (n = 2 each), and single isolates of Acetobacter, Acinetobacter, Chryseobacterium, Delftia, Enterobacter, Escherichia, and Moraxella. In the mucoid group, Pseudomonas, Staphylococcus (n = 2 each), and Stenotrophomonas (n = 1) were identified. Mycobacterial growth did not differ significantly (20% vs. 12.5%; n = 31; p = 0.65). Patients unable to produce spontaneous sputum had a higher rate of mycobacterial isolation on induced/bronchoscopic samples (43% vs. 16%; n = 54; p = 0.027), though other parameters were similar. Over 90% of measurements were obtained within three days of enrollment, and freezing did not appear to alter sputum color. Conclusions Even within a small cohort, purulent sputum was associated with higher CRP and greater bacterial growth, supporting sputum color as a rapid, inexpensive marker of disease activity in bronchiectasis. Further research should clarify whether sputum color primarily reflects bacterial colonization, airway inflammation, or both. This abstract is funded by: None

Abstract Introduction Adherence to continuous positive airway pressure (CPAP) therapy is difficult for many patients with obstructive sleep apnea. Clinical outcomes are improved with CPAP adherence ≥6 hr/night, yet scalable approaches to personalized support are limited. We developed a theory-based, clinic experience–driven conceptual dynamical model for optimizing CPAP use and applied it to a ‘just-in-time’ adaptive version of SleepWell24, a smartphone application integrating near–real-time wearable data, CPAP use, and patient-reported symptoms and CPAP-related problems with evidence-based behavior change interventions. In this feasibility optimization trial, we examined patient acceptability and initial outcomes of the adaptive SleepWell24 platform, and guided by the conceptual model, evaluated a control systems engineering approach to demonstrate, in simulation, improved CPAP adherence. Methods Aim 1: Naïve CPAP users (N=10; M age=61.7, 60% female) participated in this 60-day ongoing trial. Patients were encouraged to interact daily with SleepWell24 to report symptoms, receive personalized troubleshooting recommendations, set goals, and receive feedback on CPAP use (via Wi-Fi-enabled smart plug assessing CPAP ‘on/off state’) and sleep/activity (Fitbit). We assessed SleepWell24 use, post-intervention acceptability, and consistent CPAP use defined as ≥6hr, for ≥6nights/week for ≥2 consecutive weeks. Aim 2: The conceptual model of CPAP adherence produced a dynamical system, informed by Model Predictive Control (MPC) as a decision-making algorithm to optimize CPAP use to ≥6hr/night by tailoring actionable behavioral recommendations using patient data integrated in real-time. Results Aim 1: Across the 60-day trial, average daily SleepWell24 engagement was 72.7%. Median CPAP adherence of ≥6hr/night was 65.8%. All participants (100%) rated SleepWell24 as moderately-to-totally acceptable and would recommend it; perceived helpfulness averaged 7.0 (of 10). Eighty percent achieved consistent CPAP use. Aim 2: In simulation, the MPC framework managed CPAP-associated symptoms (e.g., nasal, anxiety, leak) and adjusted CPAP use goals, improving predicted CPAP adherence and sleep duration and quality. Conclusion SleepWell24 was engaging, acceptable, and helpful, with most users reaching optimal CPAP use. We will next estimate dynamical models using data from trial patients, a necessary step towards full automation of SleepWell24. Support (if any) AASMF #285-SR-22

Abstract Prostate adenocarcinomas (PRAD) can acquire resistance to androgen receptor signaling inhibitors through lineage transition to a cell state known as neuroendocrine prostate cancer (NEPC). Using a panel of isogenic PRAD and NEPC mouse tumoroids, we show that NEPC cells acquire new transcription factor (TF) dependencies that function in a previously undefined network. Through selective perturbation of each TF, we identify ASCL1 as a key regulator of NE lineage fate whereas MYCL functions downstream to drive NEPC growth/survival by recruitment of the TIP60/KAT5 acetyltransferase. Interestingly, while dependencies on specific TF family paralogs can vary across NEPC models, all show markedly enhanced dependency on TIP60. Moreover, the H2A.Z-acetyltransferase activity of the TIP60 complex (TIP60-C) is required for NEPC as well as the acetyl-reader BRD8, which is newly incorporated as a TIP60-C subunit with the NEPC transition. Targeted degradation studies in isogenic tumoroids reveal increased dependence on MYCL in NEPC relative to its paralog MYC in PRAD. In addition to a paralog switch (MYC to MYCL), the MYC pathway-addicted NE state is accompanied by a chaperone switch (from TIP60-C to SRCAP) for H2A.Z histone exchange and a coactivator switch (to TIP60) for MYC target gene expression. The NE-specific coupling of MYCL with TIP60 reveals a previously unappreciated opportunity to target MYC-driven NE diseases through pharmacological inhibition of TIP60.

Abstract Background and aims Patient foramen ovale (PFO) is a stroke risk factor evaluated using transthoracic echocardiogram (TTE), transesophageal echocardiogram (TEE), transcranial Doppler ultrasound (TCD), and cardiac computed tomography (CCT). TCD is non-invasive, but its diagnostic performance relative to other modalities is unclear. We hypothesized that TCD has high sensitivity but low specificity for PFO detection. Methods We conducted an IRB-approved, single-center retrospective study of patients undergoing TCD for right-to-left shunt (RLS) detection between January 2024 and April 2025. Patients were identified from the Neurosonology Laboratory Quality Database. Records were reviewed for demographics, comorbidities, and TTE, TEE, and CCT findings. Sensitivity, specificity, and positive and negative predictive values were calculated for TCD, TTE, and CCT relative to TEE, the gold standard. The sensitivity and specificity of TCD versus TTE were compared using McNemar test. Results Ninety-two patients were included. Mean age was 52.66 ± 15.78 years, and 51% were female; qualifying events included ischemic stroke or transient ischemic attack. RLS was detected in 53 patients (57.6%) by TCD, 17 (30%) by TTE, 18 (28.5%) by TEE, and 3 (21%) by CCT. TCD demonstrated 94% sensitivity and 53% specificity, (PPV 66%, NPV 89%). TTE showed 50% sensitivity and 82% specificity (PPV: 75%, NPV 61%), while CCT showed 33% sensitivity and 100% specificity (PPV 100%, NPV 33.3%). TCD had significantly higher sensitivity than TTE for RLS detection (p=0.039) with a non-significant difference in specificity (p=0.062), using TEE as the reference. Conclusions TCD has high sensitivity for RLS detection in patients with ischemic stroke or transient ischemic attack. Conflict of interest Rachel Knopp: nothing to disclose; Kelly Flemming: nothing to disclose; Eugene Scharf: nothing to disclose; Zafer Keser: nothing to disclose; Jessica Prink: nothing to disclose; Shari Johnson: nothing to disclose; Guy Reeder: nothing to disclose; Robert Brown: nothing to disclose; William Harmsen: nothing to disclose; Muhib Khan: nothing to disclose Table 1 - belongs to Results

Abstract Background and aims Rural communities have a high incidence of stroke driven by high prevalence of risk factors. We hypothesize that patient centric stroke prevention education can be delivered in rural communities. Methods High risk patients defined as Atherosclerotic Cardiovascular Disease (ASCVD) 10-year risk of ≥ 20% cardio-cerebrovascular events were identified through electronic medical records receiving primary care in Greenville and Lakeview (intervention sites) and Muskegon (control site) were included. Education material included lifestyle modification and stroke signs-symptoms information. Patients completed a pre-intervention survey, recieved standardized stroke education, and were assessed for knowledge retention through quarterly telephone follow-ups and completed a 12-month post-intervention survey. Total study cost is 130,000$ over 18 months. Results High ASCVD score was identified in 758 (Intervention) and 1128 (Control) patients. 70 intervention and 73 control patients were enrolled. Time spent consenting patients and delivering education is 5 minutes with additional 10-15 minutes at each 3-month follow-up call. 65 intervention patients completed 12 month follow up. Intervention vs. Control; Median: IQR: Age [74 (68-76) vs. 73(68-75) years; p=0.20]; Initial ASCVD [24.5 (22-30) vs. 28.6 (26-37); p<0.001], 12-month ASCVD [25(21-30) vs. 30(24-39); p=0.002). Post-intervention survey showed significant improvement in recognition of stroke risk factors (p<0.001) and stroke signs-symptoms (p<0.001). 49 (75%) patients adopted healthy lifestyle at 12-month follow up. Conclusions A primary stroke prevention cost-effective education program can be successfully implemented in a high-risk rural population, demonstrating improved stroke literacy and healthy lifestyle adoption. Conflict of interest

Abstract A posterior tibial slope (PTS) greater than 12° is an established risk factor for anterior cruciate ligament graft reconstruction failure. Reducing PTS is thus considered protective to the anterior cruciate ligament graft, and it can be achieved through an anterior closing‐wedge osteotomy. Prior to the procedure, PTS should be accurately measured to determine the amount of correction that is needed. Radiographic films remain the gold standard for measuring PTS. The purpose of this presentation is to show validated and reproducible step‐by‐step techniques for measuring PTS and anterior tibial translation for anterior closing‐wedge osteotomy using monopedal full‐length weight‐bearing tibia standing radiographs.

Abstract Background Presacral tumours are rare and heterogeneous lesions arising within a complex anatomical space, resulting in variability in diagnosis and management. Increasing incidental detection and evolving surgical and oncological strategies have highlighted the need for contemporary guidance. The aim of this study was to establish an international expert consensus on the optimal diagnosis and management of presacral tumours. Methods An international panel of colorectal surgeons from high-volume units was convened. Evidence- and practice-based statements were developed after domain-based literature reviews and refined through five online and two in-person meetings. Consensus was achieved using a modified Delphi process with anonymous voting. Results In total, 16 colorectal surgeons participated in the study. Ten domains were identified resulting in the development of 22 statements based on expert opinion and retrospective studies. After two rounds, unanimous (100%) agreement was achieved for all statements. High-resolution MRI with structured synoptic reporting is endorsed as central to risk stratification. Selective image-guided transperineal or parasacral biopsy is recommended for high-risk lesions where histology would alter management. Complete surgical resection is defined as the operative goal, with approach tailored to tumour biology and anatomy; minimally invasive surgery is considered appropriate in selected cases. Non-operative surveillance is supported for carefully selected asymptomatic, low-risk cystic lesions. Postoperative surveillance is recommended in a risk-adapted manner according to histopathology and margin status. Conclusion This international consensus provides a pragmatic, risk-stratified framework for the multidisciplinary diagnosis and management of presacral tumours. These recommendations aim to reduce practice variation, support decision-making in specialized centres, and inform future prospective collaborative research.