Pulmonary Circulation

Background and Aims: Residual pulmonary vascular obstruction (RPVO) defined as the persistence of thrombotic material within the pulmonary arteries several months after an acute pulmonary embolism (PE) is associated with an increased risk of severe complications, including recurrent events and chronic pulmonary hypertension. However, the genomic architecture underlying RPVO in unprovoked PE remains poorly understood, and this study aims to address this gap. Method: By leveraging genetic and imaging RPVO data from three independent cohorts totaling 586 unprovoked PE patients, we conducted a meta-analysis of genome wide association study (GWAS) of RPVO using a dedicated statistical method to handle the semi-continuous distribution of RPVO. The meta-GWAS was complemented by haplotype association analyses and transcriptome wide association studies as well as Mendelian Randomization (MR) approaches based on plasma metabolites and proteins. Results: Through meta-GWAS, we identified one locus, OSTN, associated with RPVO (lead variant rs59109356 associated with a ~2-fold increase of RPVO, p=3.92x10-8). A second locus, CCN4, previously reported to associate with pulmonary fibrosis, was also identified, with evidence of association approaching genome-wide significance (p=6.7x10-8). We also identified a common haplotype spanning over AHSG/HRG/KNG1 associated with a ~3-fold increase of RPVO (p=2.96x10-8). Using plasma protein-based MR, we demonstrated that one unit increase in genetically determined plasma levels of IL-1 R AcP encoding IL1RAP was associated with a 28% (p=1.32x10-6) reduction in RPVO. We also observed statistical evidence that the CCN4 (p=0.06) and IL1RAP (p=0.02) loci associate with the risk of PE recurrence in a sample of 1,617 unprovoked PE patients. Conclusions: By identifying novel molecular determinants of RPVO that map to loci involved in inflammatory pathways and vascular remodeling, our study provides evidence that inflammation is the predominant, and likely the key mechanism underlying RPVO, whereas impaired fibrinolysis appears to play a more limited role.

Pulmonary arterial hypertension (PAH) is a devastating disease with poor outcome affecting relatively young subjects. The arachidonic acid (AA) metabolite, 15-hydroxyeicosatetraenoic acid (15-HETE), has been implicated in the pathogenesis of hypoxia-induced PAH. We tested the hypothesis that genetic deletion of GPR39, the target receptor for 15-HETE, will attenuate PAH. We subjected wild-type (WT) and GPR39 KO to 4 weeks of hypoxia versus normoxia, after which right ventricular and systemic hemodynamics were measured. Immunohistochemistry of lung was performed for pulmonary arteriolar thickness as well as capillary and pericyte density. Lung tissue was also analyzed for AA and 15-HETE levels as well as signaling events (mRNA and protein levels) downtream of GPR39 activation. Unlike WT mice, GPR39 KO mice did not develop PAH. They also exhibited markedly less pulmonary ateriolar remodeling and greater pulmonary capillary density. mRNA expression of genes in the Gq, Gs and G12/13 pathways were upregulated in the WT mice while GPR39 KO hypoxic showed no change in these genes. WT and not GPR39 KO hypoxic mice exhibited enhanced AKT phosphorylation. Downstream of the phosphatidylinositol 3-kinase-AKT pathway, endothelial nitric oxide synthetase was upregulated in both WT hypoxia and GPR39 KO hypoxia mice, while sonic hedgehog was upregulated only in WT hypoxia mice. We conclude that hypoxia-induced aberrant signaling is markedly attenuated with genetic deletion of GPR39, which is associated with less pulmonary arteriolar remodeling and greater capillary density, thus preventing PAH. These results suggest that pharmacological inhibition of GPR39 may offer a novel treatment for PAH.

Rationale: Pulmonary artery (PA) enlargement is a non-invasive imaging biomarker associated with pulmonary hypertension and mortality in COPD; however, its genetic determinants remain incompletely understood. Objectives: To characterize the genetic architecture of PA size across COPD-enriched and population-based cohorts. Methods: We performed genome-wide association analyses of PA diameter using whole-genome sequencing in COPDGene (n=9,418) and ECLIPSE (n=1,859), and imputed-genotype data from the UK Biobank (n=37,073). We replicated lead variants in the Framingham Heart Study (FHS; n=3,289), incorporated all four studies into a joint meta-analysis, and identified independent signals through conditional analyses. Candidate effector genes were prioritized using coding variant annotation, colocalization, and integrative regulatory evidence. Measurements and Main Results: We identified 44 independent genome-wide significant PA diameter signals within 39 loci, including 8 variants replicated in FHS, novel associations near FRMD4B, SLC20A2, BORCS7-ASMT, and KCNRG, and 5 signals in conditional analysis including multiple signals at ANO1. Genetic effects were concordant across imaging modalities and cohorts of differing COPD burden. Effector-gene prioritization nominated ABCC8, PDGFD, HMCN1, CCNE1, and TBX20, implicating pathways in vascular remodeling, developmental regulation, smooth muscle and endothelial function, ion-channel signaling, and extracellular matrix organization. Colocalization with pulse pressure GWAS demonstrated substantial shared causal variation between pulmonary and systemic vascular biology. Conclusions: In this largest genetic study of pulmonary vascular imaging to date, PA diameter exhibits a polygenic architecture consistent across imaging modalities and cohorts of differing COPD burden. The prioritized effector genes bridge rare-variant pulmonary hypertension biology with common-variant systemic vascular biology.

Background: Pulmonary arterial hypertension (PAH) is driven by maladaptive endothelial remodeling, but the transcriptional regulators that couple proliferative stress to arterialized endothelial states remain incompletely defined. E2F transcription factor 1 (E2F1) is classically viewed as a cell-cycle regulator; whether E2F1 functions as a disease-driving node that promotes endothelial arterial programming in PAH remains unknown. Methods: We integrated human PAH lung transcriptomic analyses, deconvolution-based endothelial-state scoring, and complementary mouse and rat PH models with bulk RNA-seq, single-cell RNA-seq, pseudotime analysis, and CellChat inference. E2F1 function was tested using adenoviral E2F1 overexpression, pharmacological pan-E2F inhibition with HLM006474, and E2f1 loss on a tamoxifen-inducible endothelial Egln1-deletion background. Results: In IPAH lungs, E2F1 was increased and arterial endothelial cell (AEC) fraction and expanded arterial program scores were elevated. Similarly, Egln1Tie2Cre lungs showed increased E2F1, induction of arterial remodeling genes, and activation of an E2F target program. Genetic loss of E2f1 reduced RVSP, RV hypertrophy, vascular remodeling, and distal muscularization in Egln1-driven PH mice model. Bulk RNA-seq showed suppression of E2F/G2M, mitotic, EMT, and ECM-remodeling programs. Single-cell RNA-seq showed reduced AEC accumulation, normalized CAP1/CAP2 distribution, and reduced progression along the CAP1-iAEC-AEC trajectory. CellChat analysis identified loss of an arterial communication hub, including reduced ECM, VEGF, and Notch signaling when E2F1 is loss. Conversely, E2F1 overexpression in HLMVECs increased proliferation, activated E2F/cell-cycle and Notch/arterial programs. Pharmacological inhibition of E2F via HLM006474 suppressed VEGF-A- and hypoxia-induced endothelial proliferation and attenuated Egln1-driven and MCT-induced PH, including reversal of established MCT-PH. Conclusions: E2F1 acts as a disease-relevant transcriptional factor linking endothelial cell-cycle activation to arterial programming, matrix and angiogenic communication programs, and pulmonary vascular remodeling. Genetic or pharmacological E2F inhibition mitigates experimental PH, supporting E2F1 as a therapeutic target in PAH.

BACKGROUND Bronchopulmonary dysplasia-associated pulmonary hypertension (BPD-PH) complicates prematurity and carries substantial morbidity in extremely preterm infants. Pulmonary microvascular endothelial cell (PMVEC) dysfunction promotes capillary rarefaction and vascular remodeling, but epigenetic mechanisms after neonatal hyperoxia are poorly defined. Baf60c (SMARCD3), a SWI/SNF subunit supporting vascular homeostasis, and Smarcc2 (BAF170), a PBAF scaffold subunit linked to proliferative signaling, have not been studied together in BPD-PH. METHODS Neonatal C57BL/6 mice were exposed to 85% oxygen for 14 days. Right ventricular systolic pressure (RVSP), right ventricular hypertrophy, lung weight index, and pulmonary histopathology were assessed; PMVEC proliferation, migration, and invasion were measured. Transcriptome sequencing with GO/KEGG analyses, siRNA knockdown, LY294002 inhibition, coimmunoprecipitation, and Western blotting mapped the Baf60c-Smarcc2-PI3K-Akt-mTOR axis. A Tie1-driven, lung-tropic adeno-associated virus delivered by superficial facial vein injection at postnatal day 1 enabled PMVEC-specific Baf60c overexpression. RESULTS Hyperoxia increased RVSP, right ventricular hypertrophy, and lung weight index, impaired alveolarization, reduced capillary density, and promoted arteriolar remodeling. PMVEC function was impaired, with PI3K-Akt pathway enrichment and suppressed signaling. Hyperoxia decreased Baf60c and increased Smarcc2. Baf60c knockdown upregulated Smarcc2, suppressed PI3K-Akt-mTOR, and phenocopied hyperoxia; Smarcc2 knockdown had opposite effects. Baf60c bound Smarcc2 but not PI3K. PMVEC-specific Baf60c overexpression attenuated pulmonary hypertension and right ventricular hypertrophy and partially improved alveolar and microvascular injury. CONCLUSIONS Hyperoxia-induced BPD-PH is associated with reduced Baf60c, increased Smarcc2, and suppressed PI3K-Akt-mTOR signaling in PMVECs. Baf60c may indirectly regulate this pathway through Smarcc2. Endothelial Baf60c is a potential therapeutic target in BPD-PH.

Background: Acute pulmonary embolism (PE) is a leading cause of morbidity and mortality with persistent difficulties in choosing interventions and predicting outcomes for patients defined clinically as intermediate risk. Computational fluid dynamics (CFD) tools have been used to understand the hemodynamic environment and plan interventions in the pulmonary arteries across a variety of disease conditions. Several biomechanical metrics have been used to evaluate risk in narrowed vessels, including hemodynamic resistance, power dissipation, and fractional flow reserve (FFR). In this study, we evaluate differences in these CFD-derived biomarkers between healthy controls (HC) and intermediate risk, acute PE patients. Additionally, we examine the response of patient hemodynamics to mechanical thrombectomy and compare values of these biomarkers across post-intervention pressure status. Methods: A CFD framework was developed to simulate patient-specific hemodynamics within the pulmonary vasculature identifiable from clinical imaging. The pipeline involved reconstructing three-dimensional (3D) structures of the pulmonary arteries and modeling blood flow with the finite element method. Patient-specific boundary conditions were derived from matching pre-intervention inlet mPAP to the patient's measured value given their measured CO as steady inflow. Converged simulations allowed for precise quantification of primary hemodynamic characteristics (flow and pressure) as well as secondary flow phenomena, primarily wall shear stress (WSS) and simulated pressure metrics such as fractional flow reserve (FFR). Results: Our simulations revealed significant elevations in resistance, power dissipation, and the number of vessels with low FFR in those patients with acute PE (n=6) compared to HC (n=3). Occlusions of hemodynamic significance were generally found in segmental pulmonary arteries. For patients with normalized pulmonary pressures post-thrombectomy (n=3), we found significantly higher proximal power dissipation and counts of low FFR vessels in comparison to those with elevated pressures after intervention (n=3). Distal resistance, which was derived from the portion of resistance attributed to the outflow boundary conditions, was significantly higher in patients with elevated pressures post-intervention. Across all PE patients, FFR count was significantly correlated with post-thrombectomy pulmonary pressure and cardiac index. Discussion: CFD-derived biomarkers offer a promising tool for understanding disease severity in acute PE. Differences between HCs and acute PE patients reveal expected increases in metrics associated with proximal disease burden. Yet, in examining acute PE patients with varying post-intervention hemodynamics, we found that these metrics of proximal disease burden could also be useful to predict the efficacy of mechanical thrombectomy. Those patients with normalized pressures had higher values for proximal disease metrics and lower values for distal disease metrics than those with continued elevations in pressure. This suggests that accessibility of hemodynamically-significant emboli to thrombectomy may be useful as a predictor for outcomes.

Background: Patients with Fontan are prone to sequelae related to chronic elevations in central venous pressures. Interventions that improve venous pressures without compromising ventricular filling may therefore be of benefit. Methods We conducted a multi-center, open label, single arm pilot study of 4 weeks of dapagliflozin 10mg in adult patients with Fontan. The primary outcome was change in resting peripheral venous pressure (PVP). Secondary outcomes included changes in post-exercise PVP, peak VO2, Ve/VCO2, oxygen pulse, oxygen uptake efficiency slope (OUES), total body water, and patient reported health status according to the ACHD PRO. Results The total of 29 patients were enrolled between 11/1/2023 and 2/3/2026 across 2 centers, of whom 26 completed all study procedures. Average age was 31.2 years and 19 had a morphologic left ventricle. Dapagliflozin decreased PVP by 1.3mmHg (IQR -2.6, 0.4, p=0.012) with a greater effect in those with higher baseline PVP. Dapagliflozin improved patient reported health status and resulted in a trend towards an improvement in peak VO2 (0.2ml/kg/min, IQR -0.9, 2.2, p=0.064) and oxygen pulse (0.3ml/beat, IQR -0.6-1.1, p=0.074) without any impact on other cardiopulmonary exercise test parameters or total body water. Dapagliflozin was well tolerated in participants with no significant adverse events. Conclusions Dapagliflozin decreased PVP and improved patient reported health status in adult patients with Fontan over 4 weeks of therapy and was generally well tolerated.

Background: Children with structural heart disease (SHD), particularly congenital heart disease (CHD), are increasingly recognised as being at risk of adverse neurological outcomes. Although advances in cardiac surgery and perioperative care have markedly improved survival, epilepsy has emerged as an important long-term complication. Reported prevalence estimates vary considerably across studies, and the overall burden remains uncertain. This systematic review and meta-analysis aimed to estimate the pooled prevalence of epilepsy among children with SHD and explore differences according to geographic region, lesion characteristics, and surgical exposure. Methods: This systematic review and meta-analysis was conducted in accordance with PRISMA 2020 and MOOSE guidelines and registered in PROSPERO (CRD420261378572). PubMed/MEDLINE, Scopus, and ProQuest were searched for observational studies published between January 2000 and December 2025. Eligible studies included children aged 0-18 years with SHD or CHD reporting epilepsy prevalence or incidence. Two reviewers independently screened studies, extracted data, and assessed methodological quality using the Joanna Briggs Institute Critical Appraisal Checklist for Prevalence Studies. A random-effects meta-analysis was performed to estimate pooled prevalence with 95% confidence intervals (CI). Results: Eight cohort studies comprising 21,731 children were included. Studies were conducted across North America, Europe, and Asia and predominantly involved surgically managed CHD populations. The pooled prevalence of epilepsy was 3.0% (95% CI 1.3%-4.8%), substantially higher than estimates reported in the general paediatric population. Heterogeneity was considerable (I{superscript 2} = 98.0%; p < 0.001). The 95% prediction interval ranged from 0% to 8.1%, indicating substantial variability across populations. Narrative subgroup synthesis suggested higher epilepsy prevalence among children with cyanotic and complex lesions and among surgically managed cohorts, particularly those exposed to cardiopulmonary bypass and perioperative neurological complications. Most studies were rated as having low risk of bias, and sensitivity analyses demonstrated stable findings. Conclusions: Children with SHD have a substantially increased burden of epilepsy compared with the general paediatric population. Complex lesions, perioperative neurological injury, and cardiac surgical exposure may contribute to epileptogenesis. Long-term neurological surveillance and multidisciplinary neurodevelopmental follow-up should be integrated into routine care for children with SHD.

BackgroundPulmonary arterial hypertension (PAH) is characterized by circulating metabolic alterations, but whether these reflect disease-specific metabolic programs or reorganization of normal metabolic architecture, and how they relate to right ventricular-pulmonary vascular function (RV-PV), remains unclear. We hypothesized that the PAH metabolome is organized into biologically coherent, co-regulated metabolic modules whose relationships to RV-PV function would provide insight into known and novel metabolic pathways. MethodsWe applied weighted gene co-expression network analysis (WGCNA) to untargeted metabolomic data from 412 PAH patients enrolled in the multicenter PVDOMICS study. Module preservation analysis was performed in 85 healthy controls, with external replication in an independent single-center pulmonary hypertension cohort of 89 patients. ResultsWGCNA identified 16 distinct metabolic modules organized around biologically coherent programs. A coherent fatty acid axis, spanning substrate pools, {beta}-oxidation intermediates, and conjugated fatty acid disposal products, formed a central organizing structure, with downstream fatty acid oxidation modules strongly associated with adverse hemodynamics and worse RV-pulmonary artery (PA) coupling. Acylcholine-enriched and 5-reduced androgen metabolite modules were associated with favorable hemodynamic indices. Module architecture was largely preserved in healthy controls, with subtle disease-associated modular reorganization, rather than emergence of novel modules, observed in PAH. Core modules were recovered in the replication cohort with conserved hub metabolites. ConclusionsThese findings establish a systems-level framework demonstrating that PAH involves structured intensification and reorganization of interconnected metabolic programs associated with favorable and adverse RV-PV phenotypes. This work provides new insight into the metabolic architecture underlying PAH and identifies coordinated metabolic pathways linked to pulmonary vascular and right ventricular function.

Chronic thromboembolic pulmonary hypertension (CTEPH) is a life-threatening pulmonary vascular disease, characterized by persistent thrombotic obstruction and progressive pulmonary vascular remodeling, yet the molecular mechanisms linking persistent thrombosis to vascular remodeling remain incompletely understood. Clinical studies have reported elevated plasma von Willebrand factor (VWF) levels and reduced ADAMTS13 in patients with CTEPH, but whether VWF/ADAMTS13 dysregulation contributes directly to disease pathogenesis remains unclear. Here, using newly established rat models of CTEPH, we identify a causative role for dysregulation of the VWF-ADAMTS13 axis in chronic thromboembolic progression. CTEPH rats developed persistent, unresolved VWF- and fibrin-rich thrombi accompanied by markedly increased endothelial VWF deposition. In contrast, ADAMTS13 expression and activity were significantly reduced in CTEPH rats. Consistent with these findings, genetic Adamts13 deficiency further exacerbates pulmonary microvascular thrombosis and accelerated early mortality following disease induction. Mechanistically, ultra-large (UL)-VWF accumulated on the pulmonary endothelial surface, promoting robust platelet recruitment under shear. This platelet-VWF interaction stimulated the release of platelet-derived pro-remodeling mediators, including TGF-{beta}1 and PDGF-BB. Genetic ablation of Vwf markedly reduced in situ microvascular thrombosis within pulmonary arterioles, attenuated pulmonary arterial remodeling, and improved pulmonary hemodynamics. Moreover, treatment with recombinant ADAMTS13 reduced endothelial UL-VWF accumulation, suppressed platelet activation, and effectively prevented thrombosis and platelet-driven pro-remodeling signaling in CTEPH rats. Collectively, these findings identify dysregulation of the VWF-ADAMTS13 axis as a key driver of pulmonary thrombosis and vascular remodeling in CTEPH and support therapeutic targeting of this pathway as a potential disease-modifying strategy. Key PointsO_LIVWF-ADAMTS13 dysregulation promotes persistent pulmonary thrombosis and platelet-driven arterial remodeling within pulmonary arterioles. C_LIO_LIRecombinant ADAMTS13 treatment or VWF ablation abrogates pulmonary arterial thrombosis and halts vascular remodeling in CTEPH. C_LI

Background: Anti-synthetase syndrome (ASyS) is a subgroup of idiopathic inflammatory myopathies that is increasingly recognized as a distinct entity with features of myositis, interstitial lung disease, inflammatory arthritis, and Raynaud phenomenon. Co-reactivity with anti-Ro-52, an antibody directed against the Ro-52 E3 ubiquitin ligase, has been shown to be associated with progressive interstitial lung disease within this patient population. However, less is known regarding the association of anti-Ro-52 positivity with cardiovascular outcomes. Methods: A sub-cohort of patients with anti-synthetase antibodies at a large single institution center was retrospectively analyzed to define presence of anti-Ro-52 positivity (defined as anti-Ro-52 titer greater than or equal to 11 utilizing the line immunoblot platform, Euroline Autoimmune Inflammatory Myopathies, EuroImmun Diagnostics, Lubeck, Germany). Patients who did not meet 2017 ACR/EULAR classification criteria for idiopathic inflammatory myopathies were excluded from the final analysis. Cardiovascular outcomes ascertained via retrospective chart review included atrial fibrillation, left bundle branch block, right bundle branch block, pulmonary hypertension (confirmed via right heart catheterization), heart failure with reduced ejection fraction (HFrEF, defined as ejection fraction less than or equal to 40 percent), acute coronary syndrome (based on clinical diagnosis and angiography if available), and myocarditis (based on clinician diagnosis and either cardiac MRI or troponin elevation). When a pre-specified cardiac outcome was identified, the date of onset was recorded. Differences in proportions were analyzed via Chi-squared and Fishers exact tests, and time-to-event analyses were performed via Cox Proportional Hazards Models, incorporating a false discovery rate correction for multiple outcomes. All analyses were performed using SAS v9.4. Results: 88 patients were included in the final analysis, of whom 69 (78.4 percent) were categorized as anti-Ro-52 positive. Patients with anti-Ro-52 positivity had a higher maximum recorded serum creatine kinase (median 1297 vs 395 units per liter, p = 0.042). No significant associations between anti-Ro-52 positivity and the pre-defined cardiovascular outcomes were found over median follow up time of 12.5 years. Conclusions: In a large, single-center cohort of patients with ASyS, anti-Ro-52 positivity was not associated with an increased burden of negative cardiovascular outcomes, including the onset of pulmonary hypertension. Future studies may seek to further elucidate the mechanisms underlying the pleiotropic effects of anti-Ro-52 antibodies on the cardiopulmonary system.

Background: Approximately 40 million individuals in the US have diabetes, and 6.5 million are also afflicted with congestive heart failure (CHF). This paper outlines the natural history of CHF in T2DM and compares CHF outcomes between patients with and without T2DM. Methods: We performed a retrospective analysis of prospectively collected data from 2,008 patients hospitalized for CHF exacerbation between December 2016 and June 2019. Propensity score matching was used to match diabetics and nondiabetics. Outcomes included survival and readmission rates at 28 d, 3 mo and 6 mo, as well as comparison of echocardiographic findings. Results: A total of 2,008 patients were included. After matching, 492 patients were included, with 244 diabetics and 248 nondiabetics. After matching, readmission rates within 28 days (p=0.625) were not different, but there was a trend for higher readmission rates among diabetics at 3 months (29.3% vs. 21.5%, p=0.049) and 6 months (44.3% vs 35.8%, p=0.053). Echocardiographic characteristics, including LVEF (p=0.135), LV EDV (p=0.707), maximum velocity of mitral valve E wave (p=0.407), maximum velocity of mitral valve A wave (p=0.050), E/A ratio (p=0.501) and tricuspid valve regurgitation pressure (p=0.668) were not different in the two groups. However, tricuspid valve regurgitation velocity was higher in diabetics (3.1 vs 2.9, p=0.003). Conclusions: Although diabetes poses an additional burden for patients with CHF, survival is similar in diabetics and nondiabetics. Nonetheless, readmission rates may be higher among diabetics. Tricuspid return velocity is higher in diabetics, suggesting early pulmonary vasculature remodeling.

_ SURPASS-HF: Safety and Utility of Remote Pulmonary Artery Sensor Shared-management in Heart Failure --Background-- Insulin-dependent diabetics self-titrate therapy to self-obtained glucose values as standard of care, yet heart failure (HF) patients with implanted pulmonary artery (PA) pressure sensors never see their own readings; clinicians interpret and execute every dose change - a model that does not scale to a ~200-patient HF panel. To our knowledge, SURPASS-HF is the first prospective feasibility study applying the insulin-titration paradigm to PA-pressure-guided HF care: patients executing a prescribed loop-diuretic sliding scale, supported by ARTHUR, a domain-trained large language model, with clinician confirmation of every adjustment. --Methods-- Non-randomized, prospective, single-arm, single-center 90-day feasibility study (January 14-April 14, 2026; 60.1 patient-months). Twenty-one adults with implanted PA sensors enrolled (intention-to-treat, ITT); 19 completed full follow-up (per-protocol, PP). Regimens and individual PA diastolic (PAD) targets were explicitly prescribed; when daily pressures met published serial-reading thresholds, the software prepared the pre-determined adjustment, the clinician confirmed it, and the patient executed it. ARTHUR reinforced dose ceilings, prompted surveillance labs, and escalated edge cases for review. Pre-specified outcomes: adverse events, escalations, time in optimal PA range (TIR-PAP, +/- 5 mmHg of goal), reading adherence, provider overrides, and paired delta_PAD (first vs last 7-day windows). Confidence intervals are descriptive; the study was not powered for significance. --Results-- Mean age was 69+/-11 years, 52% women, mean baseline PAD 14.8 mmHg. No pre-specified safety event (KDIGO >or=1 AKI, hyperkalemia, hyponatremia, symptomatic hypotension) was detected (0/8 post-adjustment draws in 5/21 patients; exact 95% CI 0-37%); laboratory ascertainment was sparse, so a meaningful harm rate cannot be excluded. Seventeen of 19 PP patients (89%) required no protocol-triggered escalation; 4 escalations occurred in 2 patients. TIR-PAP was 88.4% (ITT)/91.3% (PP); reading adherence 92.1%; 53 provider alerts (0.88/patient-month) all resolved (median 24 h) with no overrides. delta_PAD was -0.89 mmHg (ITT; 95% CI -2.60 to +0.82) in a cohort already at goal at baseline. Two non-cardiac hospitalizations occurred. --Conclusions-- LLM-mediated, clinician-confirmed patient execution of a published deterministic PA-pressure-guided diuretic algorithm was feasible over 90 days, with high time-in-range and adherence and no detected safety events. Findings from this prospective, single arm, non-randomized, small cohort are descriptive. The study was not designed or powered to demonstrate evidence of a treatment effect; a randomized, well powered prospective comparison study against provider-led PA-pressure management is the next ideal step.

Background: Digoxin use after the Norwood procedure has been associated with improved interstage survival in hypoplastic left heart syndrome and related conditions. Whether this benefit translates into improved longer-term outcomes through staged palliation remains unknown. We aimed to determine the association of digoxin use at Norwood discharge with transplant-free survival and Fontan completion. Methods: We conducted a retrospective cohort study using the Pediatric Heart Network (PHN) Single Ventricle Reconstruction trial public dataset, including 549 infants enrolled at 15 North American centers between 2005 and 2008. Competing risk analysis was used to evaluate Fontan completion and Cox regression to assess death or transplantation within 6 years after the Norwood procedure. Mixed-effects models compared pre-Fontan hemodynamic and echocardiographic right ventricular indices between patients treated with and without digoxin after accounting for center clustering and adjustment for sex, shunt type, heart failure medications at Norwood discharge, and census block poverty level. Results: The 6-year cumulative incidence of Fontan completion was higher among patients discharged on digoxin than among those not receiving digoxin (82% vs 71%; p = 0.013). Competing-risk analysis accounting for death and transplant demonstrated a greater likelihood of Fontan completion among digoxin users (aHR 1.31; 95%CI 1.09-1.58; p = 0.005), without significant difference in the hazard of death or transplant (aHR 0.78; 95%CI 0.53-1.15; p = 0.208). No significant differences in pre-Fontan hemodynamic or echocardiographic indices were observed between groups. Initiation of digoxin post Stage II procedure was not associated with improved survival or likelihood to complete Fontan. Conclusion: Digoxin use at the time of Norwood discharge was associated with a 30% greater likelihood of Fontan completion by 6 years, without accompanying improvement in transplant-free survival. These findings extend prior observations of improved interstage outcomes associated with digoxin use and suggest that treatment may facilitate progression through staged palliation.

Background Ischemic heart failure (IHF) has been shown to impair contractility and disrupt sarcomere function in the left ventricle. Left ventricular failure can cause left atrial dysfunction, which is associated with a greater risk of patient mortality. Despite this, the biochemical and biomechanical characteristics of the left atrium in IHF remain obscure. Methods Myocardial mechanical properties were measured using permeabilized muscle isolated from the left ventricle (LV) and left atrium (LA) of donors and patients with IHF. Tissue homogenates from these samples were used to measure titin and myosin isoforms as well as the phosphorylation of sarcomeric regulatory proteins. Histology was used to quantify fibrosis in the patients' left ventricle and left atrium. Results Length-dependent changes in Ca2+-sensitivity were blunted in LV myocardium from patients with IHF. LA myocardium did not show robust length-dependence of Ca2+-dependent force. The calcium sensitivity of both LA and LV myocardium was increased in IHF. The maximum force generated by LV but not LA myocardium was decreased in IHF. LA myocardial samples exhibited faster contractile kinetics than LV samples, irrespective of disease. Troponin I phosphorylation decreased in both chambers with IHF. Conclusions Left atrial IHF myocardium maintained contractile force and displayed increases in calcium sensitivity, which may allow for increased LA contraction under pathological conditions. The increases in calcium sensitivity observed in ischemic myocardium of both chambers are likely driven by decreased phosphorylation of troponin I, which alters thin filament regulation. Conversely, thick filament properties of the left ventricle, such as thick filament protein isoforms and phosphorylation of myosin binding protein-C, displayed chamber-specific differences independent of disease state. These biochemical changes may explain the chamber-specific differences in kinetics and length-dependent properties. Collectively, these biophysical and biochemical data suggest LA remodeling in IHF may assist in increasing LV end-diastolic volume to maintain adequate cardiac output.

Genetic testing for inherited cardiovascular conditions is recommended by multiple national guidelines to inform medical management. However, access to genetic counseling and testing is often limited particularly in the inpatient setting. Cardiologists cite lack of access to genetic counselors as a reason for not pursuing genetic testing. Genetic test education videos have been successfully implemented in the outpatient setting to increase patient volumes and decrease wait times, but they have not been studied in the inpatient setting.

Background: Thoracic aortopathy is a disorder with genetic influence usually presenting in adulthood for which family screening is potentially desirable. Family screening is recommended, but the predictors of a positive screen and real-world pickup rates are unknown. Methods: This was a retrospective cohort of 1022 probands (first affected family member identified) with thoracic aortopathy and one or more features suggestive of a genetic etiology, and their presenting family members, assessed in a cardiac clinic (2009?2024). Imaging and genetic testing were employed in family screening. The prespecified outcomes were uptake and pickup rate of family screening, and proband and family member specific characteristics that predicted a positive family screen. Results: Among probands, 43.5% had one or more family member screened, with an average of 3 relatives per successful proband. 27.6% of family members screened positive. A pre-existing family history of aortopathy was the only variable predicting a higher incidence rate for positive family screen (p = 0.0003). Age of presentation < 60 was not predictive. For family members, extravascular features (p < 0.0001), closer relation to the proband (p < 0.02), male sex (p < 0.0001) and older age (p< 0.0001) all predicted a positive screen. Family members were eight times more likely to screen positive through imaging as compared to genetic testing. Probands with a genetic diagnosis of Marfan and Loeys Dietz syndromes accounted for only 4% of the total. Conclusions: Proband-initiated family screening for thoracic aortopathy has a high yield of affected individuals, even among older probands.

Background. Septal reduction therapy (SRT) is recommended in drug-refractory, symptomatic obstructive hypertrophic cardiomyopathy (oHCM). We evaluated whether aficamten, a novel cardiac myosin inhibitor, can reliably transition guideline-eligible SRT candidates to ineligibility, and the associated safety profile of aficamten in this group. Methods. We analyzed participants with oHCM enrolled in FOREST-HCM (NCT04848506), the long-term open-label extension study of aficamten, from 28 May 2021 to 9 May 2025. Results. Three hundred and fifteen patients were included, of whom 104 met 2024 ACC/AHA guideline criteria for SRT eligibility at baseline. The SRT-eligible cohort was predominantly female (57%), with mean resting and Valsalva left ventricular outflow tract (LVOT) gradients of 63 {+/-} 39 and 109 {+/-} 42 mmHg, and all were in New York Heart Association (NYHA) class III. All baseline SRT-eligible patients became SRT-ineligible with aficamten therapy during study follow-up over a median of 42 days (IQR: 17, 49), except for one participant who withdrew from the study to pursue SRT (total of 3 participants withdrew). After dose titration, 3/104 (2.9%) remained guideline-eligible; by week 72 no patients met eligibility criteria. At maintenance, resting and Valsalva LVOT gradients improved by a least-squares mean of ?41 mmHg ([95% CI ?44 to ?37]; P<0.0001) and ?56 mmHg ([95% CI ?62 to ?51]; P<0.0001), respectively. Relative to baseline, NT-proBNP improved by 77% (95% CI 74 ? 80%), high-sensitivity cardiac troponin I decreased by 38% (95% CI 30 ? 46%), KCCQ-CSS improved by a mean of 20.2 (SD 19.3) points, and 95.2% of SRT-eligible patients had improved by ?1 NYHA class. Overall, the safety profile was favorable, with 2 occurrences of left ventricular ejection fraction (LVEF) < 50% over 193.7 patient-years of follow-up (1 event per 100 patient-years), managed by down-titration. There were no baseline SRT-eligible patients who died or developed LVEF <40%. Conclusions. Aficamten resolved guideline eligibility for SRT in nearly all baseline-eligible patients, with rapid and durable improvements in hemodynamics, symptoms, biomarkers and health status sustained for up to 3.5 years. Instances of LVEF <50% were rare and without clinical sequelae. These data support aficamten as a safe and effective alternative to SRT in oHCM.

Background and Aims Genetic testing in dilated cardiomyopathy (DCM) guides risk stratification and family screening. Likely pathogenic or pathogenic (LP/P) variants are identified in approximately one-third of patients, leaving many without a genetic diagnosis. Cohort studies suggest that "gene-elusive" patients have a lower risk of adverse events. This study aims to better characterise this group and identify factors associated with adverse outcomes. Methods Consecutive and unrelated DCM patients undergoing genetic testing and returning no LP/P variants were retrospectively recruited and compared to two control cohorts of DCM patients carrying LP/P variants in LMNA and TTN for a primary composite endpoint of end-stage heart failure (ESHF) or malignant ventricular arrhythmia (MVA). Results Among patients without prior MVA, the composite endpoint occurred in 36/423 (8.5%) gene-elusive, 14/39 (35.9%) LMNA and 11/100 (11%) TTN cardiomyopathy patients (log-rank p<0.001 for LMNA vs gene-elusive and LMNA vs TTN; p=0.96 for TTN vs gene-elusive). For gene-elusive patients, lower left ventricular ejection fraction, larger left ventricular internal diameter in diastole, absence of LBBB and ventricular ectopy on ECG were independent predictors of the primary endpoint. Gene-elusive patients with LBBB had less atrial arrhythmia and a lower burden of ventricular ectopy at baseline and a low risk of the primary composite endpoint (HR 0.3 [0.1-0.8], p-value 0.01). Conclusions Gene-elusive DCM patients have a risk of adverse events similar to TTN cardiomyopathy. Gene-elusive patients with LBBB form a particularly low-risk subgroup, likely reflecting a distinct aetiology of left ventricular systolic dysfunction.

As an intrinsically mechanosensitive organ, the lung experiences a range of mechanical forces. Chronic obstructive pulmonary disease (COPD) involves abnormal macroscopic cellular and extracellular matrix (ECM) changes that impact mechanical properties of the lung. Mechanosensitive Piezo1/2 channels are expressed in the lung including on airway smooth muscle cells (ASM) that mediate cellular responses to stretch and ECM biomechanics. The expression and roles of Piezos in COPD lung ASM are not known. We hypothesized that Piezo expression and activation are altered in COPD lung ASM influencing ECM regulation. Distribution of Piezo proteins in ASM and epithelium of small airways of COPD stage II and IV vs. non-COPD controls was assessed using immunohistochemistry and ImageJ (n=10-17/group). Isolated ASM cells from control (n=6) vs. COPD stage II and IV patients (n=3 each stage) were exposed to stretch or the Piezo1 agonist Yoda1 followed by measurement of ECM gene and protein expression. Less Piezo2 staining was observed in COPD IV patients compared to controls, with lesser area and intensity of staining in the epithelial layer, and lower intensity of staining in ASM and small airways as a whole. Fura-2-based imaging of ASM Ca2+ showed lower influx after Yoda1 exposure in COPD II compared to control and COPD IV. Gene expression of Piezo1 increased upon stretching in controls but not in COPD ASM, while Piezo2 protein expression decreased with stretching in all groups. Yoda1 treatment resulted in decreased collagen1, fibulin1 and periostin gene and collagen 1 and periostin protein expression in ASM. Overall, these results support a role for Piezo activation in abnormal ECM-ASM cell crosstalk in COPD.