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Abstract BACKGROUND Ivosidenib is an oral inhibitor of mutant isocitrate dehydrogenase type I (IDH1) currently approved for the treatment of IDH1 mutated acute myeloid leukemia and myelodysplastic syndrome (MDS). Hematopoietic stem and progenitor cells carrying preleukemic mutations, referred to as clonal hematopoiesis (CH), are the origin of myeloid neoplasms (MN). Individuals who have cytopenias and CH, but do not meet diagnostic criteria for a hematologic malignancy, are classified as having Clonal Cytopenias of Undetermined Significance (CCUS), a condition associated with a high risk of progression to MN. While CCUS patients (pts) can have multiple mutations, they show lower mutational burden on average compared to MN. Thus, we hypothesized that treatment with ivosidenib would improve cytopenias in IDH1-mutant CCUS. METHODS; We performed a decentralized phase II single-arm study to characterize the safety and efficacy of ivosidenib in IDH1-mutant CCUS (NCT0503044). Drug was shipped to pts with local oncologists performing standard-of-care clinical exams supplemented by study team lead interviews for adverse event monitoring. Research labs were drawn by local providers or through Quest. QT corrected interval (QTc) was monitored through a mobile electrocardiogram device (AliveCor). Eligible patients were aged ≥ 18 years and had confirmed IDH1-mutant CCUS with at least 6 months of unexplained cytopenias (hemoglobin<10 g/dL, platelets<100 x109/L or absolute neutrophil count <1.8 x109/L). The primary endpoint was hematologic response of at least 8 weeks in duration based on the IWG 2006 criteria for MDS. RESULTS 20 pts with IDH1-mutant CCUS have been enrolled. Most were male (70%) with a median age of 66 (range 41-79). Overall, 74% had a self-reported race of non-Hispanic white, 11% of Hispanic white, 5% of Asian and 11% of black or African American. Most pts presented with neutropenia (95%) including some with co-occurring thrombocytopenia (21%). One pt presented with anemia and thrombocytopenia without neutropenia. Prior to treatment, the average number of co-mutations beyond IDH1 was 2 (range 0-3), with most pts (74%) harboring a co-occurring spliceosome gene mutation. The IDH1 variant allele fraction (VAF) was lower in the blood (mean=19%, range 3-35%) than in the bone marrow (mean=31%, range 18-43%) in most (93%) patients. Out of the 20 enrolled pts, 17 received at least 8 weeks of therapy at the time of our data cutoff (7/29/2025) and were included in the efficacy analysis. Grade ≥3 adverse events (AEs) occurred in five patients (26%) including two with grade ≥3 treatment-related adverse events (pancytopenia and sepsis in the first pt, rash in the second pt). The most common all-grade treatment-related adverse events were nausea (n=5, 26%), prolonged QTc (n=3, 16%), anemia (n=3, 16%), and diarrhea (n=3, 16%). There were no instances of reported differentiation syndrome. Overall, 82% of pts achieved a hematologic response (14/17) including improvement in neutropenia (88%) and thrombocytopenia (75%). With a median follow-up of 16 months (range 0.6-24 months), the median duration of hematologic response was not reached. Among responders, 86% had a continued response at one year. Two pts progressed to MDS after 4 and 17 months of treatment characterized by recurrence of cytopenias and the emergence of new clones. A surveillance bone marrow biopsy was performed at 18 cycles for the 8 pts who remained on treatment with none showing disease progression. Most pts (90%, N=9/10) treated for at least 12 months had a decrease in IDH1-mutant CH VAF over time and 40% (N=4/10) showed IDH1 mutation clearance (VAF <2%) with a median time to clearance of 9 months. Among those with decreasing IDH1 clonal burden, all had a corresponding decrease in other co-occurring mutations present at baseline with one responder showing emergence of a newly detectable CHEK2 mutation without disease progression. CONCLUSIONS Decentralized trials represent a feasible solution for the conduct of clinical trials in rare hematologic neoplasms and precursor conditions. Ivosidenib was well-tolerated and induced durable hematologic remissions in IDH1-mutant CCUS. Most pts showed a reduction in clonal burden with mutation clearance commonly seen with long-term treatment demonstrating that ivosidenib modifies the natural history of IDH1-mutant CCUS.

Abstract Introduction Pronounced disparities in pediatric B-lymphoblastic leukemia (B-ALL) outcomes by race and ethnicity persist in the contemporary era. Gaps in overall survival (OS) from initial diagnosis are wider than event-free survival, suggesting that post-relapse mechanisms may contribute. However, data on treatment and outcomes after relapse are lacking. In a large, multicenter, real-world cohort of children and young adults with high-risk 1st relapse of B-ALL, we sought to (1) define survival outcomes by race/ethnicity and (2) explore if differences in therapy utilization drive outcomes. Methods We conducted an analysis within the Retrospective Study of Contemporary Approaches to 1st Relapse in B-ALL (ReCALL-1) cohort, which includes patients <30 years who initiated 1st relapse therapy between 2018-2022. This analysis was restricted to patients treated at US centers for “high-risk” 1st relapse, defined as relapse for which hematopoietic cell transplant (HCT) is generally standard-of-care: Early relapse (medullary <36m; isolated extramedullary <18m), late relapse with persistent end of reinduction disease, Ph+ B-ALL or age ≥18 years. Patients with Trisomy 21, those who received cell therapy before relapse and those who died during reinduction were excluded. The primary exposure was race/ethnicity categorized as Hispanic, non-Hispanic Black (NHB), non-Hispanic White (NHW), and other/unknown. The primary outcome was OS from relapse. Multivariable Cox regression models were constructed to include other social drivers of health (SDOH; health insurance, preferred language) and disease characteristics. Results Of 479 patients in ReCALL-1, 311 from 31 centers met inclusion for this analysis (41% Hispanic, 7% NHB, 46% NHW, 5% NH-other/unknown). With a median follow-up of 47m, OS differed by race/ethnicity (log-rank p=0.017): Hispanic, 4y OS 59%; NHB, 37%; NHW, 68%. Compared to NHW patients, NHB patients had an increased hazard of death (HR 2.3, 95% CI 1.3-4.3, p=0.006), while Hispanic patients were more similar to NHW patients (HR 1.3, 95% CI 0.9-2.0, p=0.16). Adjustment for SDOH only marginally attenuated the risk for NHB patients (aHR 2.0, 95% CI, 1.1-3.7, p=0.031) and led to equivalent outcomes for Hispanic patients (aHR 0.9, 95% CI, 0.5-1.5, p=0.66). Adjusting for disease characteristics that differed by race/ethnicity at p<0.2 (time to relapse, Ph+, Ph-like, KMT2Ar, age ≥18, or relapsed infant ALL) did not diminish the risk for NHB patients (aHR 2.0, 95% CI, 1.1-3.7, p=0.032) while outcomes remained equivalent for Hispanic patients (aHR 1.2, 95% CI, 0.8-1.8, p=0.40). Point estimates of cumulative incidence of non-relapse mortality (NRM) were highest in NHB patients (Hispanic, 4y NRM 13%, NHB 22%, NHW 11%), but this trend was not statistically significant (Gray’s p=0.52). Only 17% of patients initiated therapy for relapse on a clinical trial with no differences observed by race/ethnicity. Most patients received definitive treatment for relapse with either CAR T cell therapy (CART) or HCT: 79% overall, 74% Hispanic, 91% NHB, and 83% NHW. CART and HCT were utilized equally (39% and 40%, respectively) and the proportion that received each therapy did not vary by race/ethnicity. Time to CART/HCT, external referral for treatment, receipt of investigational v commercial CART, and use of post-CART consolidative HCT revealed no differences by race/ethnicity. Of the 66 patients (21%) who did not receive cell therapy, 26 had planned for CART or HCT, but did not receive due to disease progression or NRM (n=24; 12 Hispanic, 10 NHW), or insurance barriers (n=2, both Hispanic). After HCT, OS was worse for NHB patients (log-rank p=0.03) with 4y OS of 42% v 85% for NHW and 75% for Hispanic. Post-CART, 4y OS was 40% for NHB v 59% for NHW and 51% for Hispanic, but this difference was not statistically significant. Conclusion In a large real-world cohort of children with high-risk 1st relapse of B-ALL, we found a two-fold increased hazard of death for NHB patients compared to NHW patients, even after adjustment for other SDOH factors and high-risk disease features. In contrast to previous studies of adult patients, children appeared to have equal access to cell therapies across races/ethnicities. We found that Hispanic patients, who comprised >40% of the cohort, had similar survival to NHW children, suggesting that availability of cellular and immunotherapies may be mitigating historically observed disparities for children with relapsed B-ALL.

Abstract Introduction: Sexual health is an important part of overall well-being for adolescents and young adults (AYAs) after hematopoietic stem cell transplantation (HCT). AYAs have unique sexual health needs as they navigate development, relationships, and identity formation. AYA patients may experience sexual dysfunction due to conditioning chemotherapy/radiation therapy, graft-versus-host disease (GVHD), changes in body image, mental health effects, relationship shifts, and the challenges of dating with a serious illness. We surveyed both pediatric and adult HCT providers at our institution to assess current practices of discussing sexual health needs with AYAs as well as barriers to these discussions in order to guide interventions to improve communication. Methods: Adult and pediatric HCT physicians, advanced practice providers, and nurse coordinators in the Mayo Clinic Rochester HCT program completed an online survey to understand their perspectives about addressing sexual health needs in AYA HCT survivors. This survey covered current practice patterns in discussing sexual health and managing sexual health needs, barriers to providing sexual health care, and recommendations for provider education. Results: This survey included responses from 25 HCT providers (35% response rate): 22 adult providers and 3 pediatric providers. The respondents comprised of 10 physicians (40%), 8 advanced practice providers (32%), and 7 nurses (28%). Most of the providers saw 6-10 AYA patients per month (48%), while others reported: 1-5 AYAs (36%), 11-15 AYAs (12%), and 16-20 AYAs (4%); no provider saw 21 or more. While all respondents felt sexual health was an important topic for AYA HCT patients, most (80%) also reported rarely (44%) or only sometimes (36%) discussing sexual health with AYA patients. Primary barriers included inadequate knowledge of resources for referrals (72%), insufficient training on this topic (60%), limited time for discussion (56%), discomfort discussing sexual health with AYAs (32%), and concern about patient discomfort (28%). When it came to screening for GVHD, 28% of respondents reported not regularly screening for genitourinary GVHD and 40% indicated feeling uncomfortable or very uncomfortable managing it. Frequently discussed topics included fertility (64%) and contraception (52%). Almost all respondents (96%) expressed interest in further education. Topics of interest included an overview of common sexual health issues in AYA HCT survivors (88%), medical management of sexual health concerns such as erectile dysfunction, low libido, and vaginal dryness (72%), management of psychosocial concerns impacting body image and relationships (64%), cultural considerations for addressing sexual health (56%), providing inclusive care for lesbian, gay, bisexual, trans, queer or questioning (LGBTQ) AYAs (56%), genitourinary GVHD (56%), and safer sex practices during and after transplant (52%). Discussion: Although regular sexual health assessment in HCT survivors is recommended, most providers at our institution did not routinely discuss sexual health with AYAs. While genitourinary GVHD is an important HCT-specific sexual health topic, screening for this condition is not consistently performed. Providers were eager for further education and identified several topic areas for future educational interventions. Our data will aid in the development of an educational intervention for providers covering key sexual health issues in AYA HCT survivors, including medical and psychosocial management of sexual health concerns, as well as inclusive care for intercultural and LGBTQ AYAs, with the aim of improving frequency of sexual health discussions and provider confidence. Time constraints were identified as a key barrier, so patient-focused educational interventions that can occur outside of the clinical appointment may be an opportunity to deliver information and empower patients to raise specific concerns during their visits. In combination with healthcare provider-focused education, this may promote critical sexual health-related discussions during appointments.

Abstract INTRODUCTION Outcomes for 1st relapse of pediatric B-lymphoblastic leukemia (B-ALL), especially high/intermediate-risk (HR/IR) relapse, remain unacceptably poor. Limited enrollment of this population on cooperative group clinical trials has impeded our ability to study potentially effective regimens. In the current era, patients can access innovative immunotherapies commercially. However, there is no mechanism to capture outcomes for these off-study patients and no comparative effectiveness data to guide treatment selection. METHODS We conducted a multicenter, retrospective study of patients <30 years who initiated 1st relapse therapy at a participating center from 2018-2022 (ReCALL-1 Study). Objectives were to define real-world survival outcomes, compare response rates of reinduction strategies, describe the post-reinduction treatment landscape, and, for patients with HR/IR relapse, assess the comparative effectiveness (CE) of blinatumomab to hematopoietic cell transplant (blina/HCT) v CD19 CAR T cells (CART). For the CE analysis, we emulated an open-label, randomized study of blina/HCT v CART who achieved an M1/M2 marrow at the end of an intensive reinduction (EoRI). Patients were classified by their intended treatment at EoRI. Cox regression models were used to adjust for unbalanced patient and disease features by arms. The primary outcome was overall survival (OS) from EoRI. RESULTS The full cohort included 479 patients from 33 centers (31 US, 2 international). Median time to relapse was 31 months (m); 77% had bone marrow (BM) involvement and 31% central nervous sytem involvement. With a median follow-up of 49m from relapse, 4 year (y) OS, event-free survival (EFS), and non-relapse mortality (NRM) were 64%, 43%, and 13%, respectively. Among patients with very early BM (<18m, n=79), early BM (18-35m, n=76), late BM (≥36m, n=162), and isolated CNS (n=85) relapses, 4y OS/EFS were 29%/20%, 57%/35%, 78%/49%, and 84%/61%, respectively. Only 19% received reinduction therapy on a clinical trial. Among patients with BM disease, R3 reinduction (n=179) and VXLD (n=61) had identical MRD-negative (<0.01%) CR rates of 38% (p=1.00) and equivalent treatment failure (TF; M3 or extramedullary disease) rates: R3, 8% v VXLD 7%, p=0.79. Blina (n=33) and inotuzumab-based (n=21) reinductions achieved MRD-negative CR rates of 39% and 52%, respectively, but higher TF rates of 39% and 24%. Reinduction mortality was 2%: R3, n=5; VXLD, n=3; 3-drug reinduction, n=1. Overall, as part of 1st relapse therapy, 36% received CART (78% commercial product), 44% HCT, 40% blina, and 11% inotuzumab. The emulated trial included 159 patients, 95 on blina/HCT and 64 on CART. Study arms were well matched by demographics, cytogenetics, and relapse sites, but CART patients were more likely to have relapsed <18m from diagnosis (34% v 24%) and have EoRI M2 marrows (31% v 11%), and less likely to have private insurance (36% v 51%). Unadjusted OS was comparable between arms (log rank p=0.18): CART, 60% at 4y; blina/HCT, 71%, as was NRM (10% v 13% at 4y). EFS was lower for CART (p=0.049): 4y EFS 35% v 49% for blina/HCT. After adjustment for unbalanced covariates, the hazard of death was equivalent for CART as compared to blina/HCT (aHR 1.1, 95% CI 0.6-2.1, p=0.67) and EFS became more comparable (aHR 1.3, 95% CI 0.8-2.1, p=0.22). 91% of blina/HCT and 97% of CART received their intended cell therapy; time from EoRI to cell therapy was shorter for CART (67 v 86 days, p<.001). In the CART arm, 34% underwent consolidative HCT; 1/3 were preplanned and 2/3 due to loss of B cell aplasia or NGS-MRD positivity. Of those with a 2nd relapse, CART patients were more likely to be CD19 negative (47% v 10%, p=0.003). CONCLUSION In this multicenter, real-world cohort of children treated for 1st relapse in the immunotherapy era, suboptimal outcomes for early BM relapse persisted, with particularly dismal 4y OS of 29% for relapses <18m after diagnosis. In contrast, survival for late BM and isolated CNS relapses compared favorably to historic data. Only 1 in 5 patients initiated relapse therapy on a clinical trial and although 1st relapse is not an approved indication for commercial CART in pediatrics, 36% received CART. In an emulated trial of post-reinduction blina/HCT v CART, adjusted EFS and OS were comparable, suggesting that CART may be a viable alternative to HCT for select patients. Post hoc analyses will identify whether specific subgroups may benefit more from one strategy.

ABSTRACT Alzheimer's disease (AD), a leading cause of dementia in the elderly, is traditionally characterized by neurodegeneration driven by amyloid‐beta plaques and tau tangles. However, emerging evidence reveals that AD's impact extends beyond the brain, significantly affecting skeletal health. This review integrates clinical and transgenic mouse model data to elucidate the mechanistic interplay between AD pathology and bone metabolism. AD patients exhibit increased risk for hip fractures and low bone mineral density (BMD), independent of cognitive impairment severity. We found altered calcium and alkaline phosphate levels in the blood of patients with mild cognitive impairment and AD, as assessed from the Alzheimer's Disease Neuroimaging Initiative data. Convergent risk factors—age, sex, APOE4 genotype, smoking, and vitamin D deficiency—contribute to both neurodegeneration and bone fragility. Key molecular pathways, such as Wnt/β‐catenin signaling and TREM2‐mediated osteoclast regulation, underscore shared mechanisms driving disease pathology in both systems. Mouse models of AD consistently demonstrate disrupted bone remodeling, impaired osteoblast function, and heightened osteoclast activity. Therapeutic strategies targeting overlapping pathways, including lithium, anti‐FSH antibodies, and NF‐κB inhibitors, show promise in mitigating both cognitive decline and bone loss. Collectively, these insights advocate for a more integrated view of AD that includes skeletal comorbidities, potentially guiding the development of dual‐purpose interventions.

ABSTRACT Background The Extracorporeal Life Support Organization recommends daily antithrombin monitoring and supplementation to achieve > 50%–80% activity during extracorporeal membrane oxygenation (ECMO). Evidence supporting this practice is uncertain, and whether it confers clinical benefit or harm is unclear. Methods This was a systematic review with meta‐analysis to evaluate the safety and efficacy of antithrombin supplementation during ECMO. We systematically searched databases and registers for studies comparing patients on ECMO who received antithrombin supplementation to those who did not. Random effects meta‐analysis was performed. Risk of bias was independently assessed by two investigators. A priori subgroup and sensitivity analyses were performed to explore reasons for heterogeneity. Results A total of 11 studies were identified. In the pooled meta‐analysis, antithrombin supplementation resulted in no difference in bleeding events (OR 1.38, 95% CI, 0.88–2.17, p = 0.16), thrombotic events (OR 1.57, 95% CI, 0.84–2.90, p = 0.15), or mortality (OR 1.21, 95% CI, 0.81–1.81, p = 0.35) when compared to those who did not receive antithrombin. Subgroup analysis revealed no difference in bleeding events or mortality in pediatric or adult patients; however, pediatric patients that received antithrombin were more likely to experience a thrombotic event (OR 1.70, 95% CI, 1.51–1.91). Sensitivity analysis in only low risk of bias studies confirmed these findings. Conclusions Antithrombin supplementation was not associated with differences in mortality or hemostatic outcomes during ECMO support and may be associated with harm in pediatric patients on ECMO.

Importance Treatment for cognitive dysfunction due to postacute sequelae of long COVID (ie, symptoms of fatigue, malaise, weakness, confusion that persist beyond 12 weeks after an initial COVID infection) remains a significant unmet need. Objective To test evidence-based rehabilitation strategies for improving cognitive symptoms in persons with long COVID. Design, Setting, and Participants This was a 5-arm, multicenter, randomized clinical trial of 3 remotely delivered interventions conducted between August 17, 2023, and June 10, 2024. The study took place at 22 trial sites and included the screening of individuals with cognitive long COVID. Interventions Participants were randomized to 1 of 5 arms: adaptive computerized cognitive training (BrainHQ [Posit Science]), cognitive-behavioral rehabilitation involving both group and individual counseling sessions (PASC-Cognitive Recovery [PASC-CoRE]) paired with BrainHQ, and transcranial direct current stimulation (tDCS) paired with BrainHQ. Two comparator arms were included as follows: unstructured computer puzzles and games (active comparator) and sham tDCS paired with BrainHQ. The interventions occurred 5 times per week over 10 weeks. Main Outcomes and Measures Cognitive and behavioral in-person assessments were performed at baseline, midintervention, at the end of intervention, and 3 months after the end of the intervention. The primary outcome measure was the modified Everyday Cognition Scale 2 (ECog2) completed at the end of the intervention compared to the baseline visit based on participant self-report looking back over the prior 7 days. Results A total of 378 individuals were screened, from which there were 328 participants (median [IQR] age, 48.0 [37.0-58.0] years; 241 female [73.5%]; race: 15 Asian [4.6%], 47 Black [14.3%], and 235 White [71.6%]; ethnicity: 52 Hispanic [15.9%]). None of the 3 active interventions demonstrated benefits on the modified ECog2 in the intention-to-treat population by the end of the intervention period. The adjusted differences in mean change were 0.0 (95% CI, −0.2 to 0.2) for BrainHQ vs active comparator, 0.1 (95% CI, −0.1 to 0.3) for PASC-CoRE + BrainHQ vs active comparator, 0.0 (95% CI, −0.2 to 0.2) for tDCS-active + BrainHQ vs tDCS-sham + BrainHQ, and 0.1 (95% CI, −0.1 to 0.3) for PASC-CoRE + BrainHQ vs BrainHQ alone. Secondary participant-reported outcomes and neuropsychological tests showed no differential benefits for any treatment arm. All 5 arms demonstrated some improvements over time on the modified ECog2 and on secondary outcomes. There were no serious adverse events attributable to the interventions. Conclusions and Relevance This phase 2 randomized clinical trial failed to demonstrate differential benefits for online cognitive training, a structured cognitive rehabilitation program, and tDCS for cognitive long COVID. Trial Registration ClinicalTrials.gov Identifier: NCT05965739 .

Introduction Semaglutide, a glucagon-like peptide-1 receptor agonist (GLP-1RA) used to treat type 2 diabetes mellitus (T2D), has potential associations with higher rates of diabetic retinopathy (DR) complications including proliferative DR (PDR) and diabetic macular edema (DME). The purpose of this study was to determine whether an association exists between semaglutide and PDR and treatment-requiring DR/DME. Research design and methods This was a retrospective cohort study of 14 databases (six administrative claims and eight electronic health records) in the Observational Health Data Sciences and Informatics Evidence Network. Adults with T2D on semaglutide, other GLP-1RA (dulaglutide, exenatide), or non-GLP-1RA medications (empagliflozin, sitagliptin, glipizide) from 1 December 2017 to 31 December 2023 were included. The association between semaglutide and PDR or treatment-requiring DR/DME was assessed using an active-comparator cohort design comparing new users of semaglutide as second-line T2D treatment to those on other GLP-1RAs and non-GLP-1RAs. Propensity score-adjusted Cox proportional hazards models were used to estimate hazard ratios (HRs). Network-wide HR estimates were generated using a random-effects meta-analysis. Results The study included 810 390 new semaglutide users for T2D. PDR risk for semaglutide was similar to dulaglutide (HR 0.81, 95% CI 0.42 to 1.54, p=0.51), empagliflozin (HR 0.83, 95% CI 0.53 to 1.30, p=0.41) and sitagliptin (HR 0.83, 95% CI 0.45 to 1.55, p=0.57) but was lower than glipizide (HR 0.59, 95% CI 0.39 to 0.88, p=0.01). The risk for treatment-requiring DR/DME for semaglutide was similar to empagliflozin (HR 0.66, 95% CI 0.43 to 1.02, p=0.06) but lower than dulaglutide (HR 0.53, 95% CI 0.31 to 0.91, p=0.02), sitagliptin (HR 0.46, 95% CI 0.26 to 0.81, p=0.008) and glipizide (HR 0.55, 95% CI 0.33 to 0.91, p=0.02). Conclusions and relevance We did not identify increased risk for either PDR or treatment-requiring DR/DME comparing semaglutide with other GLP-1RAs or non-GLP-1RAs. Patients with T2D should still undergo close eye care follow-up, particularly when initiating new antihyperglycemic medications.

Background: Fontan circulation is characterized by the absence of a subpulmonary ventricle with resultant systemic venous hypertension. Despite exercise intolerance being nearly universal in this population, the determinants of exercise capacity in this population are still poorly understood. Research Question: We investigated the prevalence of peripheral impairment and assessed the contribution of peripheral O 2 extraction versus central hemodynamics to peak O 2 consumption (pVO 2 ) post-Fontan palliation. Methods: This single-center retrospective cross-sectional study compared 52 consecutive adults post-Fontan procedure who underwent exercise catheterization to patients with heart failure with preserved ejection fraction (HFpEF) and non-cardiac dyspnea (NCD) at 1:1 ratio. Several previously reported measures for peripheral O 2 extraction were evaluated in the absence of a golden standard. Correlates of pVO 2 were identified by multivariate linear regression analyses using the backward selection method. Results: Patients with Fontan circulation were younger [age 32 (24;36) years] and tended to have a lower body mass index [26 (23; 29) kg/m 2 ] compared to patients with HFpEF [70 (57; 75) years, p<0.001 and 33 (27; 39) kg/m 2 , p<0.001] and NCD [48 (38; 61) years, p<0.001 and 27 (24; 35) kg/m 2 , p=0.08]. Peak heart rate [108 (85;126) vs 108 (95;125) bpm] and indexed stroke volume [46 (39;54) vs 45 (40;53) ml/m 2 ] were similar in the Fontan and HFpEF groups but lower compared to NCD [126 (108;141) bpm, p<0.001 and 51 (45;59) ml/m 2 , p<0.001]. Peak mean pulmonary artery pressures were highest in HFpEF [45 (41;50) mmHg, p<0.001], followed by Fontan and NCD [26 (22;31) vs 23 (19;25) mmHg, p=0.03]. Median peak O 2 extraction post-Fontan was comparable to HFpEF [12 (10;14) vs 11 (10;13) ml/dl, p=0.17] but higher than in NCD [10 (9;12) ml/dl, p<0.001]. It was <14 ml/dl in 73% compared to 94% and 98% of patients with HFpEF and NCD [p<0.001]. O 2 extraction ratio was <70% in 62% compared to 60% in HFpEF and 96% in NCD [p<0.001]. Correlates of pVO 2 post-Fontan were peak O 2 extraction [β 0.5±0.1 per ml/dl; p<0.001], mean pulmonary artery pressures [β -0.2±0.05 per mmHg; p=0.002], heart rate [β 0.03±0.01 per bpm; p=0.01], and systolic arterial blood pressure [β 0.03±0.01 per mmHg; p=0.02]. Conclusion: Impaired O 2 extraction is prevalent amongst adults post-Fontan. Whether exercise can modulate this important determinant of exercise capacity post-Fontan merits further investigation.

Abstract The incidence of venous thromboembolism (VTE) in patients with acute lymphoblastic leukemia (ALL) receiving asparaginase-based induction is high despite primary thromboprophylaxis. Our aim was to derive and externally validate a VTE risk prediction model in patients with ALL receiving asparaginase-based induction. We conducted a multicenter retrospective cohort study of patients (aged ≥18 years) with newly diagnosed ALL receiving asparaginase-based induction. The derivation and external validation cohorts included 306 and 94 patients, respectively. Primary outcome was VTE at any site. A cause-specific Cox proportional hazards model stratified by thromboprophylaxis and center was performed to identify VTE risk factors in the derivation cohort. A risk prediction model for VTE at 30 days was derived using variables with P value &lt; .05 in the multivariable model and was tested in the validation cohort. VTE risk factors on multivariable analysis in the derivation cohort included D-dimer ≥1 μg fibrinogen equivalent unit per mL (hazard ratio [HR], 2.64; 95% confidence interval [CI], 1.07-6.5) and hemoglobin (HR for each 1 g/dL increment, 1.19; 95% CI, 1.06-1.34) at ALL diagnosis. A VTE risk score based on these variables distinguished between a 4% (95% CI, 0.72-12) and 20% (95% CI, 14-27) 30-day cumulative incidence of VTE in the derivation cohort, with similar findings in the validation cohort (area under the curve, 0.56). The negative predictive value for VTE at 30 days was 96% and 93% in the derivation and validation cohorts, respectively, and the positive predictive value was 20% in both. We derived and validated a model using D-dimer and hemoglobin, which stratifies VTE risk in patients with ALL receiving asparaginase-based induction.