Citations

Respiratory muscle fatigue could occur following involuntary breathing movements during maximal breath-holds. We measured respiratory muscle strength pre and post three preparatory and maximal breath-holds. We found significant reductions in diaphragm strength and total inspiratory and expiratory strength in some, but not all, divers. Divers that had respiratory muscle fatigue had a lower pseudo O 2 delivery (HR × [Formula: see text]) during the struggle phase. This suggests that reduced oxygen delivery may contribute to respiratory muscle fatigue during a breath-hold.

Abstract BRCA-associated homologous recombination deficiency (HRD) is present in ~ 50% of high-grade serous carcinomas (HGSC) and predicts sensitivity to platinum-based therapy. However, there is little understanding of why some patients with BRCA-deficient tumors experience unexpectedly poor outcomes. We profiled 154 tumors, enriched for patients with BRCA-deficient tumors that experienced short overall survival (≤ 3 years, n = 42), using whole-genome, transcriptome, and methylation analyses. All but one BRCA-deficient tumor exceeded an accepted HRD genomic scarring threshold. However, patients with BRCA1-deficient HGSC with a more elevated HRD score survived significantly longer. Patients with BRCA2-deficient HGSC and loss of NF1 survived twice as long as those without NF1 loss, whereas PIK3CA or RAD21 amplification defined BRCA2-deficient HGSC with exceptionally short survival. BRCA1-deficient tumors in short survivors had evidence of immunosuppressive c-kit signaling and EMT. In a large HGSC cohort (n = 1,389) including 282 individuals with pathogenic germline BRCA variants (gBRCApv), the location of the mutation within functional domains stratified clinical outcomes. Notably, residual disease after primary surgery had limited prognostic effect in gBRCApv-carriers compared to non-carriers. Our findings indicate that tumor HR proficiency in the context of therapy response and survival is not a binary property, and highlight genomic and immune modifiers of outcomes in BRCA-deficient HGSC.

ABSTRACTSurgical biopsy of brainstem tumors carries a risk of neurological injury. We performed magnetic resonance spectroscopy (MRS) of 2‐hydroxyglutarate (2HG) and glycine in patients with brainstem tumors to assess the feasibility of detecting and quantifying 2HG in the brainstem to obviate the need for a diagnostic biopsy and to establish the clinical significance of glycine MRS in brainstem tumors in vivo. Twenty adult patients with radiographically identified presumed brainstem gliomas were prospectively enrolled in the study. Proton MRS was obtained at 3T with a protocol tailored for detection of 2HG and glycine (TE 97‐ms PRESS). Spectra were fit using LCModel software and in‐house basis signals of metabolites and lipids. The metabolite concentrations were quantified with reference to water and examined with respect to clinical outcomes, including postgadolinium MRI and overall survival time. MRS data from 19 patients were included in subsequent analysis, excluding suboptimal data from one patient. Tumors with elevated 2HG (> 1.9 mM, N = 8) and undetectable 2HG (< 0.3 mM, N = 11) were clearly distinguishable. Tumors with elevated glycine (> 1.5 mM, N = 4) showed rapid progression. Kaplan–Meier survival analyses with metabolite measures demonstrated that tumors with 2HG higher than 1.0 mM were significantly associated with a favorable prognosis (p = 0.01). In contrast, tumors with glycine higher than 2.5 mM showed a strong association with poor survival (p = 0.0005). The data confirm detection of 2HG in brainstem tumors at a concentration that is consistent with an IDH mutation and expected good prognosis, whereas elevated glycine in brainstem tumors portends rapid tumor progression and a worse prognosis.

Abstract BACKGROUND Tau‐derived cerebrospinal fluid (CSF) biomarkers correlate with amyloid‐beta (Aβ) plaques or tau tangles in Alzheimer's disease (AD). This study assessed the effects of long‐term anti‐Aβ antibodies on amyloid plaques, tau tangles, and CSF tau species to determine the relationships between them. METHODS A post‐hoc analysis of the DIAN‐TU‐001 trial (NCT01760005) examined 142 participants at risk for dominantly inherited AD randomized to solanezumab ( n = 50), gantenerumab ( n = 52), or placebo ( n = 40). High‐resolution mass spectrometry quantified CSF tau species over four years. RESULTS Phosphorylated tau (p‐tau) species (153, 181, 217, 231) increased early in preclinical AD but were reduced with gantenerumab‐mediated Aβ plaque reduction. Nearly a decade later, MTBR‐tau243 and p‐tau205 increased, showing no association with Aβ reduction, aligning with tau tangle pathology progression. DISCUSSION Initially changing soluble p‐tau species track Aβ plaque reduction, while ptau205 and MTBR‐243 reflect tau tangle pathology, informing different pathways of therapeutic strategies. Highlights p‐tau217 and p‐tau231 correlate with Aβ‐PET and respond to Aβ‐plaque lowering therapies. Aβ immunotherapy trials support a direct link between p‐tau changes and Aβ plaques Gantenerumab reduces Aβ plaques but does not affect tau NFT‐related biomarkers. Blood‐based p‐tau217 assays may provide a non‐invasive tool to monitor Aβ therapies. MTBR‐tau243 strongly correlates with tau PET and tracks NFT pathology progression. Further studies are needed to validate tau biomarkers for tracking NFT‐targeting therapies.

Abstract Background Surgical resection without visible or residual microscopic disease (R0 resection) is known as the optimal path to cure localized pancreatic cancer (PDAC). Neoadjuvant therapy (NAT) is used to improve R0 resection rates; however, the optimal regimen is unclear. We assessed the safety and efficacy of peri-operative gemcitabine/nab-paclitaxel (GEM/NAB) and pre-operative stereotactic body radiotherapy (SBRT) in patients with resectable (R-PDAC) and borderline resectable PDAC (BR-PDAC). Patients and Methods This was a prospective, multicenter single arm phase 2 study in patients with R-PDAC and BR-PDAC. Patients received three cycles of GEM/NAB prior to SBRT followed by surgery and three cycles of adjuvant GEM/NAB. Primary endpoint was R0 surgical resection rate in each cohort. Secondary endpoints included safety and overall survival (OS). Results Eighty-six patients consented and following radiologic screening, 49 were enrolled into two cohorts: R-PDAC (n = 20) and BR-PDAC (n = 29) between June 2016 and April 2021. Seventy percent of R-PDAC (14/20) and 55.2% of BR-PDAC patients (16/29) completed all NAT. Eleven R-PDAC (55.0%) and 11 BR-PDAC patients (37.9%) underwent surgical resection. Nine R-PDAC (45.0%) and 9 BR-PDAC patients (31.0%) had R0 resections. The median OS for R-PDAC and BR-PDAC patients with R0 resections was 22 months (95% CI: 17.7 months-NA) and 39 months (95%CI: 13.21 months-NA), respectively. Conclusion While the trial failed to meet one of its primary objectives as only 45% of R-PDAC patients had an R0 resection, the objective of 30% R0 resection for the BR-PDAC group was met. NAT should be part of current therapeutic strategies for BR-PDAC; however, our trial does not answer what is the best NAT for BR-PDAC. Trial Registration NCT02723331

Abstract Background and Aims The TRISCEND II trial demonstrated superior clinical benefits for patients with ≥severe tricuspid regurgitation (TR) treated with the EVOQUE transcatheter tricuspid valve replacement (TTVR) system plus medical therapy vs medical therapy alone. This work reports 1-year and 18-month outcomes in patients stratified by baseline TR severity. Methods The multicentre, prospective TRISCEND II trial enrolled 400 patients with symptomatic, ≥severe TR, and randomized 2:1 to TTVR (n = 267) or control (n = 133). In a post hoc analysis, patients were stratified into severe TR (n = 172) and massive/torrential TR (n = 220) cohorts. Clinical and quality-of-life outcomes were reported at 1 year, with Kaplan–Meier estimates for all-cause mortality and heart failure (HF) hospitalization assessed at 18 months. Study oversight included an independent echocardiographic core laboratory, clinical events committee, and data safety monitoring board. Results One year after TTVR, TR was ≤mild in 95.2% of severe TR and 95.3% of massive/torrential TR patients. The primary safety and effectiveness endpoint (win ratio) favoured TTVR over control regardless of baseline TR severity: severe {1.64 [95% confidence interval (CI): 1.11, 2.43]} and massive/torrential [2.20 (1.55, 3.14)]. At 18 months, TTVR patients had similar mortality to controls [rate difference: severe 0.2% (−11.6, 11.9), massive/torrential −5.8% (−17.6, 6.0)], whereas HF hospitalization rates favoured TTVR in the massive/torrential cohort [vs control, severe 9.8% (−3.0, 22.7), massive/torrential -15.2% (−28.9, −1.5)]. Conclusions Patients with ≥severe TR benefit from TTVR, experiencing improvements in TR severity, functional capacity, and quality of life regardless of baseline TR severity, with a signal for greater benefit in patients with more advanced disease.

ImportanceBurnout remains prevalent among physicians and can negatively affect quality, safety, and cost of patient care. Few randomized studies on interventions to address burnout have been conducted to date.ObjectiveTo determine whether wearing a smartwatch and having access to its physiological data (eg, sleep, step count, and heart rate) improves physician well-being (and if so, which dimensions of well-being).Design, Setting, and ParticipantsThis randomized clinical trial included physicians at 2 US medical centers (Mayo Clinic and the University of Colorado School of Medicine) who volunteered to wear a provided smartwatch beginning June 7, 2023. The study concluded on June 27, 2024.InterventionSix months of wearing a smartwatch.Main Outcomes and MeasuresBurnout, resilience, quality of life, depressive symptoms, stress, and sleepiness were measured using validated scales. Participants completed electronic surveys at baseline and 3, 6, 9, and 12 months. An intention-to-treat analysis was conducted.ResultsThis study included 184 physicians (mean [SD] age, 37.5 [9.3] years; 107 females [58.8%]). A total of 83 of 183 physicians (45.4%) were residents or fellows, 103 of 184 (56.0%) lived in Colorado, and 99 of 182 (54.4%) worked in non–primary care settings. Baseline levels of well-being across the measured dimensions were similar for the 2 study arms. At 6 months, 35 of 85 physicians (41.2%) in the intervention arm had burnout compared with 46 of 91 (50.5%) in the control arm (P = .21). Mean (SD) resilience scores at 6 months were 31.9 (5.0) and 29.5 (6.2) among physicians in the intervention and control arms, respectively (P = .01). In multivariable analysis adjusting for baseline score, demographics, specialty, and work hours, the prevalence of burnout was lower (odds ratio, 0.46 [95% CI, 0.21-0.99]; P = .046) and mean resilience score was higher (parameter estimate [scale, 0-40], 1.20 points [95% CI, 0.11-2.28 points]; P = .03; Cohen d = 0.17) among physicians in the intervention arm vs the control arm after 6 months.Conclusions and RelevanceIn this randomized clinical trial to evaluate the effect of wearing a smartwatch and having access to its physiological data on physician well-being, physicians who wore a smartwatch experienced improvements in burnout and resilience. Future research should explore whether engagement with smartwatch data leads to actual behavior change (eg, adaptive coping or reflective habits) that reduces burnout risk and enhances resilience.Trial RegistrationClinicalTrials.gov Identifier: NCT05463250

Abstract The link between regional tau load and clinical manifestation of Alzheimer’s disease (AD) highlights the importance of characterizing spatial tau distribution across disease variants. In typical (memory-predominant) AD, the spatial progression of tau pathology mirrors the functional connections from temporal lobe epicentres. However, given the limited spatial heterogeneity of tau in typical AD, atypical (non-amnestic-predominant) AD variants with distinct tau patterns provide a key opportunity to investigate the universality of connectivity as a scaffold for tau progression. In this large-scale, multicentre study across 14 international sites, we included cross-sectional tau-PET data from 320 individuals with atypical AD (n = 139 posterior cortical atrophy/PCA-AD; n = 103 logopenic variant primary progressive aphasia/lvPPA-AD; n = 35 behavioural variant AD/bvAD; n = 43 corticobasal syndrome/CBS-AD), with a subset of individuals (n = 78) having longitudinal tau-PET data. Additionally, as an independent sample, we included regional post-mortem tau stainings from 93 atypical AD patients from two sites (n = 19 PCA-AD, n = 32 lvPPA-AD, n = 23 bvAD, n = 19 CBS-AD). Gaussian mixture modelling was used to harmonize different tau-PET tracers by transforming tau-PET standardized uptake value ratios to tau positivity probabilities (a uniform scale ranging from 0% to 100%). Using linear regression, we assessed whether brain regions with stronger resting-state functional MRI-based functional connectivity, derived from healthy elderly controls in the Alzheimer’s Disease Neuroimaging Initiative (ADNI), showed greater covariance in cross-sectional and longitudinal tau-PET and post-mortem tau pathology. Furthermore, we examined whether functional connectivity of tau-PET epicentres (i.e. the top 5% of regions with the highest baseline tau load) and tau-PET accumulation epicentres (i.e. the top 5% of regions with the highest tau accumulation rates) was associated with cross-sectional and longitudinal tau patterns. Our findings show that tau-PET epicentres aligned with clinical variants, e.g. a visual network predominant pattern in PCA-AD (‘visual AD’) and left-hemispheric temporal predominance, particularly within the language network, in lvPPA-AD (‘language AD’). Moreover, more strongly functionally connected regions showed correlated concurrent tau-PET levels (confirmed with post-mortem data) and tau-PET accumulation rates. The functional connectivity profile of tau-PET epicentres and accumulation epicentres corresponded to tau-PET progression patterns, with higher tau-PET levels and accumulation rates in functionally close regions, and lower tau-PET levels and accumulation rates in functionally distant regions. Our data are consistent with the hypothesis that tau propagation occurs along functional connections originating from local epicentres, across all AD clinical variants. Since tau proteinopathy is a major driver of neurodegeneration and cognitive decline, this finding may advance personalized medicine and participant-specific end points in clinical trials.

Abstract Background and Aims Invasive coronary function testing (CFT) identifies coronary vasomotor disorders in up to 90% of patients with angina with non-obstructive coronary arteries (ANOCA). The ILIAS ANOCA trial hypothesized that routine ad hoc CFT would be feasible, safe, and effective in providing an early, comprehensive diagnosis. Additionally, it was anticipated that combining CFT with a disease-specific treatment protocol would significantly improve quality of life in ANOCA patients compared with standard care. Methods After excluding patients with obstructive coronary artery disease (CAD) during clinically indicated invasive coronary angiography (ICA), eligible patients underwent CFT and were randomized to either the standard care group, where CFT results remained blinded, or the intervention group, where CFT results were disclosed along with a tailored medical therapy protocol. The primary outcome was the mean difference in the within-subject change in Seattle Angina Questionnaire summary score (SAQSS) between groups from baseline to a follow-up of 6 months. The trial is registered with the International Clinical Trials Registry Platform (NL-OMON20739). Results A total of 255 patients consented, of whom 153 patients (60%) without CAD underwent CFT and were randomized 1:1 to the standard care (n = 76) or intervention group (n = 77). All CFT procedures were successful without adverse events. A vasomotor disorder was identified in 120 patients (78%). At 6-month follow-up, the SAQSS improved significantly in the intervention group compared with the control group, with an intervention effect of 9.4 units (95% confidence interval 3.9–14.9, P = .001). There were no major adverse cardiac events at the 6-month follow-up. Conclusions Routine CFT during the initial ICA was feasible, safe, and had high diagnostic yield. Implementing a pragmatic CFT protocol combined with a disease-specific treatment protocol significantly improved disease-related quality of life in patients with ANOCA compared with standard care.