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.

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: 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: 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.

_ 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. 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.

We examined whether polygenic risk for peripheral artery disease (PAD) is associated with severity among patients undergoing lower extremity revascularization at Yale New Haven Hospital. Patients were classified into European (EUR) and non-European (non-EUR) ancestry groups. Associations between the 19-variant polygenic score (PGS) and nine severity indicators were evaluated using linear and Cox regression models stratified by ancestry, followed by meta-analysis. Significant findings (p < 0.05) were assessed for replication in the UK Biobank (UKB). After quality control, 68 EUR and 59 non-EUR patients were included. In EUR patients, higher PGS was associated with increased risk for stroke (HR = 2.43, 95% CI 1.06-5.57). Meta-analysis revealed a significant association between higher PGS and younger age at surgery ({beta} = -2.90, SE = 1.28), which was replicated in the UKB ({beta} = -0.58, SE = 0.15). These results suggest genetic risk contributes to PAD severity.

Background: Neonatal-onset hypertrophic cardiomyopathy (HCM) is a rare condition with limited data regarding clinical presentation, genetic background, and long-term outcomes. We aimed to characterize the phenotype and prognosis of HCM presenting in neonates. Methods: This is a multicenter retrospective study including patients diagnosed with HCM before 1 year of age. Neonatal-onset HCM was defined as presentation {less than or equal to}28 days of life. Clinical, genetic, instrumental data, treatment, and outcomes were collected. Primary outcome included overall and cardiac survival, major arrhythmic events (MAEs), implantable cardioverter-defibrillator (ICD) implantation, and cardiac surgery. Results: Among 321 pediatric HCM, 21% were diagnosed during infancy and 75% were neonates. Median age at diagnosis was 1 day (IQR 0-6), 82% presented within the first week of life. Prenatal suspicion was in 25%. At presentation, 41% were symptomatic. RASopathies represented the most common etiology (41%), followed by gene-elusive (31%), mitochondrial/inborn errors of metabolism (18%), and sarcomeric (8%). Left ventricular outflow tract obstruction was frequent in sarcomeric and RASopathy. Overall survival was 92% and cardiac survival was 96% at 2 years; long-term survival was 88% at 30 years. ICDs were implanted in 8%; 21% required cardiac surgery. Survival free from ICD was 40% at 15 year and 47% from myectomy. All events occurred in patients presenting within the first weeks of life. Conclusions: Neonatal-onset HCM is characterized by etiologic heterogeneity, predominance of syndromic and non-sarcomeric etiologies, and long-term cardiovascular morbidity. Presentation within the first days of life identifies a high-risk subgroup requiring intensive surveillance and specialized multidisciplinary management.

Background: Outpatient chronic heart failure (HF) assessment relies on NYHA class and distance-based testing that can obscure physiological heterogeneity. Near-infrared spectroscopy (NIRS) enables tissue oxygenation phenotyping but is underexplored during standardized stressors in outpatient HF. We tested whether wearable NIRS-derived oxygenation kinetics during a vascular occlusion test (VOT) and six-minute walk test (6MWT) differ across NYHA classes. Methods: In this prospective, single-center pilot study, 44 chronic HF outpatients (mean age 70.9 {+/-} 8.7 years, 75% male; NYHA I [n=19], II [n=12], III [n=13]) were monitored with a novel wearable NIRS device (NIRSense Envello Core) during a VOT and 6MWT. Primary endpoints were the post-occlusion net area under the curve (net AUC; VOT) and post-walk recovery net AUC (modified 6MWT). Secondary endpoints included the exertional tissue oxygenation (Oxy) nadir, VOT reperfusion kinetics, gait metrics, and tolerability. Results: Despite NYHA I and II walking identical median distances (420 m), post-walk recovery net AUC was lower in NYHA II (-16.3 a.u.xs) and III (-12.8 a.u.xs) than NYHA I (46.1 a.u.xs, p=0.004). The exertional Oxy nadir did not differ (p=0.722), but NYHA III walked 27% and 38% slower than NYHA II and I (p<0.001). NYHA II had higher VOT net AUC (134.2 a.u.xs) than NYHA I (71.9; p=0.018) and III (61.1; p=0.011). Post-walk recovery net AUC correlated with gait velocity (rs=0.44) and distance (rs=0.39; both p<0.05). VOT net AUC did not correlate with functional metrics, but resting reperfusion kinetics correlated with 6MWT performance (rs=0.41-0.46, p<0.05). The sensor was well tolerated. Conclusions: Wearable NIRS-derived recovery kinetics differentiated NYHA I from NYHA II despite these classes walking identical median distances. Coupled with distinct resting VOT hyperemic differences, these preliminary findings indicate wearable NIRS may capture physiological heterogeneity in outpatient HF not reflected by NYHA class and standard functional metrics.

An autocrine pro-adhesive/pro-contractile signaling loop, through the mechanosensitive transcriptional cofactor YAP, promotes fibrosis. The CCN family of matricellular proteins modify adhesive signaling. Of these, CCN3 is antifibrotic. We show that BLR-200, a CCN3-derived peptide, has anti-fibrotic properties in the bleomycin-induced model of scleroderma skin fibrosis. In vitro, BLR-200 delayed, but did not abolish, fibroblast adhesion to collagen and nuclear YAP localization. In vivo, BLR-200 prevented/treated bleomycin-induced skin fibrosis, and reduced bleomycin-induced expression of profibrotic genes including alpha-smooth muscle actin, CCN1 and CCN2. Lineage tracing and scRNA-seq analyses revealed that the myofibroblasts in this model were quantitatively derived from collagen-lineage Pi16+/Col15+ve fibroblasts. BLR-200 prevented myofibroblast differentiation in this model and trajectory of fibroblasts toward a Sfrp2-positive subset, a cell type associated with poor clinical outcome. BLR-200 impairs YAP activation in vitro and appearance of translationally-relevant fibroblast subtypes in vivo and is a novel anti-fibrotic agent for SSc skin fibrosis.

Background: Heart failure with preserved ejection fraction (HFpEF) is a heterogeneous syndrome comprising multiple pathophysiological phenotypes. HFpEF trials have largely enrolled diverse populations and reported average treatment effects, consistently yielding neutral results that may obscure drug-specific benefits within distinct subgroups. To address this issue, we employ an interaction-based that incorporates treatment-by-variable interactions to uncover drug-specific responses. Methods: We leveraged four HFpEF clinical trials (TOPCAT, RELAX, NEAT-HFpEF, INDIE-HFpEF) and developed a framework comprising two complementary approaches. The first employed a prognostic responder model to evaluate whether conventional responder definitions reflect treatment-specific benefit or instead capture favorable clinical trajectories common to both treatment and placebo groups. The second used an interaction-based individual treatment effect (ITE) modeling to identify baseline variables that modify therapy effect, distinguishing drug-specific response from prognostic phenotypes. Results: Although the prognostic responder model demonstrated good discrimination, further analisys suggested it primarily captured a prognostic signal associated with favorable clinical trajectories common to both treatment and placebo arms. In contrast, the ITE model identified distinct, drug-specific effect modifiers across trials (cardiorenal-inflammatory for spironolactone (TOPCAT), NO-mediated anti-inflammatory for isosorbide mononitrate (NEAT-HFpEF), afterload-reducing for inorganic nitrite (INDIE-HFpEF), and anti-volume-overload for sildenafil (RELAX). Each ITE model demonstrated significance only within its own trial suggesting drug-specific signal. Conclusions: The proposed method identifies mechanism-specific effect modifiers, and uncovers clinically meaningful heterogeneity in treatment response, which is not captured by conventional MCID-based approaches. Although exploratory, these findings support phenotype-guided therapy in HFpEF and argue for phenotype-informed trial design to enhance treatment-effect detection and therapy targeting.

Heart failure with preserved ejection fraction (HFpEF) commonly coexists with atrial fibrillation (AF), but shared mechanisms remain unclear. In this study, we hypothesized that Pitx2, a transcription factor located near the strongest genetic locus associated with AF in humans, increases susceptibility to HFpEF-like remodeling. We also sought to understand pathways that might be central to this increased risk. Male and female Pitx2+/- mice and wild-type littermates received 3-week subcutaneous osmotic pump infusion of saline or angiotensin II (Ang II; 500 ng/kg/min). Cardiac structure and function were assessed by echocardiography and catheterization, and functional capacity by exercise treadmill. RNA transcriptomic profiling was performed to identify candidate pathways. In a separate cohort, Ang II-treated mice were randomized to oral GKT136901 (30 mg/kg/day) or vehicle during infusion. After Ang II infusion, Pitx2+/- mice developed exaggerated HFpEF-like changes, including greater left ventricular hypertrophy, left atrial enlargement, diastolic dysfunction, elevated left ventricular end-diastolic pressure, and reduced treadmill performance. RNA-seq showed enrichment of metabolic and stress-response pathways with selective upregulation of Nox4, confirmed by RT-qPCR. GKT136901 attenuated structural remodeling, diastolic dysfunction indices, elevated filling pressures, and cardiomyocyte hypertrophy, but did not improve endurance. These findings implicate redox signaling, including Nox4, in AF genetic susceptibility-HFpEF interactions.

Background: Transthyretin amyloidosis cardiomyopathy (ATTR-CM) is an infiltrative cardiomyopathy and an increasingly recognized cause of heart failure. With improved survival from disease-modifying therapies, an increasing number of patients are presenting for surgery and may be at increased risk of adverse postoperative outcomes. This study reports outcomes of ATTR-CM patients undergoing surgery and evaluates the utility of the Revised Cardiac Risk Index (RCRI), a perioperative risk tool. Methods: A total of 145 ATTR-CM patients were included, among which 51 patients underwent at least one eligible surgical procedure. Preoperative risk was assessed using the RCRI, analyzed both as a categorical and as a dichotomized ({greater than or equal to}3 vs <3) variable. Postoperative outcomes included unplanned hospital admission, length of stay (LOS), prolonged hospitalization (>48 hours), and major adverse cardiac events. Models were adjusted for frailty (Clinical Frailty Scale {greater than or equal to}5) and major surgery, using multivariable, ordinal, and Firth penalized logistic regression analyses. Results: Patients were predominantly male (86%) with a mean age of 76 {plus minus} 9 years, and 61% were frail. Higher RCRI scores were associated with unplanned postoperative hospital admission (RCRI {greater than or equal to}3: adjusted OR 48.9, 95% CI 4.8-502.2) and longer LOS (RCRI {greater than or equal to}3: adjusted OR 40.7, 95% CI 4.3-382.8). RCRI {greater than or equal to}3 was also associated with prolonged hospitalization (>48 hours) in Firth penalized logistic regression, whereas frailty was not independently associated. Conclusions: In a real-world ATTR-CM cohort undergoing major non-cardiac surgery, the overall risk of adverse outcomes was low, and higher RCRI scores were associated with increased postoperative hospital admission and longer LOS, including hospitalization exceeding 48 hours. The RCRI retains prognostic utility in this high-risk cohort and may support peri-operative risk stratification.

Background: The saphenous vein (SV) remains the most widely used graft in coronary artery bypass grafting (CABG). However, graft failure over the years has compromised long-term outcomes. Preservation of the vascular endothelium is fundamental for vein graft patency, and hydrogen sulfide (H2S) a protective gasotransmitter, plays a significant role in vascular homeostasis. This study evaluated how different intraoperative preservation solutions modulate H2S-synthesizing enzymes and endothelial integrity. Methods: SV segments from 20 CABG patients were subdivided into five groups: Control (immediate fixation), normal saline (NS; 0.9% NaCl), autologous heparinized arterial blood (AHB), histidine-tryptophan-ketoglutarate (HTK) solution, and a damage group (no solution for 30 minutes). Structural integrity was evaluated by measuring endothelial coverage using light microscopy, and the expression of eNOS, CD31, and H2S pathway enzymes (CSE, CBS, and 3-MPST) was assessed by immunofluorescence (IF) and confocal microscopy to determine mean fluorescence intensity (MFI). Results: LM analysis revealed that AHB (89.66% {+/-} 3.02) and HTK (88.72% {+/-} 3.07) preserved endothelial coverage significantly better than NS (78.06% {+/-} 4.48) and the Damage Group (76.82% {+/-} 4.90; p < 0.001). In IF, all interventions reduced eNOS and CD31 expression compared to the control, but AHB and HTK maintained significantly higher levels than NS (p < 0.001). All three H2S-producing enzymes were detected in the GSV endothelium, with CSE being the most expressed isoform. The use of NS caused a marked depletion of these enzymes, while AHB and HTK showed specific superiority in preserving H2S synthesizing enzymes. Conclusions: The choice of preservation solution significantly affects endothelial integrity and the modulation of enzymatic H2S synthesis. NS proved to be deleterious to the endothelium, whereas AHB and HTK better preserved vascular structure and function, suggesting their clinical superiority for the preparation of venous grafts during CABG.

BackgroundRare heterozygous loss-of-function (LoF) variants in SVIL, encoding the Z-disk and costameric protein supervillin, have recently been identified as a cause of hypertrophic cardiomyopathy (HCM). Although supervillin is implicated in actin-dependent mechanotransduction, the mechanisms linking SVIL deficiency to cardiomyopathy remain poorly understood. Homozygous LoF cause a novel skeletal Myofibrillar Myopathy-10 (MFM-10) while heterozygous LoF cause HCM without skeletal myopathy. In this study we use a human model system to disentangle the LoF pathomechanism of the scaffolding protein supervillin in cardiomyocytes and its clinical implications. MethodsUsing CRISPR/Cas-9 we engineered a representative pathogenic LoF variant Q255X into an isogenic induced pluripotent stem cell (iPSC) line creating the heterozygous SVILQ255X/+ and homozygous SVILQ255X/Q255X cell lines. These lines were differentiated into iPSC-derived cardiomyocytes (iPSC-CMs) and cellular phenotypes were assessed using bulk RNA-sequencing, LC-MS proteomics, electrophysiological and calcium handling analyses, contractility measurements, sarcomere organization analysis, Seahorse metabolic flux assay, and pharmacological intervention with mavacamten. ResultsThe Q255X variant resulted in SVIL haploinsufficiency at both RNA and protein levels with no evidence of a truncated protein. Compared with isogenic controls, SVILQ255X/+ iPSC-CMs demonstrated action potential shortening, calcium transient elongation, sarcomeric disorganization and hypertrophy, and impaired mitochondrial respiration. Multi-omic analyses of SVILQ255X/+ iPSC-CMs showed a profile of cellular stress and inflammation, hypertrophic and pro-fibrotic signalling, and a pseudohypoxic state driven by decreased respiration and a HIF-induced glycolytic shift. These abnormalities were not present in SVILQ255X/Q255X cardiomyocytes, consistent with a relatively limited cardiac phenotype reported in homozygous variant carriers. Mavacamten improved sarcomeric disorganization and hypertrophy in SVILQ255X/+ cells but did not rescue energetic compromise. ConclusionsPathogenic heterozygous SVIL LoF produces a distinct cellular phenotype characterized by impaired mechanotransduction, mitochondrial dysfunction, and maladaptive metabolic remodelling that promotes hypertrophic and pro-fibrotic signalling. These findings define a mechanistic basis for SVIL-associated cardiomyopathy and identify metabolic dysfunction as a potential therapeutic target beyond sarcomere-directed therapy. Clinical PerspectiveO_ST_ABSWhat Is New?C_ST_ABSO_LISVIL haploinsufficiency causes HCM through a mechanism distinct from canonical sarcomeric disease, characterized by impaired mechanotransduction, mitochondrial dysfunction, and pseudohypoxia-driven metabolic remodeling. C_LIO_LIHeterozygous SVIL loss of function produces a substantially more severe cardiomyocyte phenotype than homozygous loss of function, providing a mechanistic explanation for the predominance of cardiac disease in heterozygous variant carriers. C_LIO_LIMavacamten improves sarcomeric organization but does not restore impaired mitochondrial respiration, demonstrating that energetic dysfunction persists despite sarcomere-directed therapy. C_LI What Are the Clinical Implications?O_LIOur findings give functional evidence to support SVIL as a clinically relevant HCM disease gene and its inclusion in clinical genetic testing panels. C_LIO_LIThese findings establish SVIL-associated cardiomyopathy as a mechanistically distinct form of HCM and offer insight into the pathomechanism of Z-disk and costameric HCM C_LIO_LIThe persistence of mitochondrial dysfunction despite myosin inhibition suggests that drugs targeting mitochondrial bioenergetics may be a therapeutic strategy in patients with SVIL-associated cardiomyopathy. C_LI

The endothelial cells (ECs) that line blood vessels continuously sense and respond to the physical forces exerted by blood flow. In vivo, pulsatile arterial flow interacts with vessel curvature, branching and other anatomical features to generate complex local hemodynamic environments that dictate the magnitude, direction, pulsatility, and oscillatory nature of wall shear stress experienced by ECs. Currently, accessible and reproducible in vitro models of complex pulsatile flow that recapitulate in vivo vascular anatomy remain limited. Here, we combine a novel rotational-flow endothelial culture platform with detailed computational fluid dynamics (CFD) modeling to characterize four well geometries designed to generate distinct hemodynamic environments. CFD analyses demonstrate that these geometries intrinsically generate pulsatile flow and produce reproducible spatially distinct regions of wall shear stress magnitude, pulsatility, and oscillatory shear within a single culture well. Endothelial alignment mapping and functional assays reveal region-specific cellular responses to the predicted local flow conditions that closely corresponded to the predicted local hemodynamic environment, linking complex flow patterns to endothelial adaptation. The technical advancements of our modeling efforts should support a faster, cheaper, simpler, and--importantly--validated framework for future investigation into EC mechanobiology under complex flow conditions. HIGHLIGHTSO_LISimple engineered well geometries generate distinct hemodynamic microenvironments, mimicking in vivo vascular structures, using a conventional orbital shaker. C_LIO_LIComputational fluid dynamics (CFD) reveals spatially distinct patterns of wall shear stress, pulsatility, and oscillatory shear applied to ECs within individual culture wells. C_LIO_LIHigh average wall shear stress and elevated oscillatory shear index induces a unique perpendicular alignment of ECs to the dominant flow vector. C_LI

AimsWhile the muscle-enriched microRNA-378a (miR-378a) has been implicated in cardiac hypertrophy and stress responses, its role in maintaining cardiomyocyte metabolic homeostasis, mitochondrial function, and angiogenic paracrine signaling under physiological and post-injury conditions remains unclear. This study addresses these gaps by examining the molecular and functional consequences of miR-378a deficiency in murine heart and human cardiomyocytes. Methods and ResultsCardiac structure and function were analyzed in miR-378a-deficient (miR-378a-/-) and wild-type (miR-378a+/+) mice at 12 weeks and 17 months of age, revealing that miR-378a loss promoted myocardial fibrosis, altered IGF1R-AKT signaling, and impaired cardiac performance, with age-dependent effects. Integrated transcriptomic and proteomic analyses in miR-378a-/- and control mice, as well as in human iPSC-derived cardiomyocytes (hiPSC-CM) of both genotypes, revealed deregulated pathways related to translation, metabolism, and cardiomyopathy-associated signaling. In hiPSC-CM, miR-378a knockout (KO) impaired mitochondrial respiration, disrupted mitochondrial morphology, and reduced mitochondrial DNA content, accompanied by altered mitophagy and biogenesis. KO cells also showed increased glucose uptake but reduced glycogen storage, accompanied by changes in key metabolic regulators, and displayed diminished angiogenic potential. Finally, hiPSC-CM overexpressing miR-378a were delivered in a mouse model of acute myocardial infarction, but overexpression did not further enhance their therapeutic effect. ConclusionsThis study broadens our understanding of miR-378as physiological role in murine hearts and human cardiomyocytes, demonstrating its impact on contractility, mitochondrial integrity, glucose metabolism, and angiogenic paracrine signaling. However, overexpression of miR-378a in hiPSC-CM offers limited additional benefit in cell therapy for acute myocardial infarction.

Background: Aspirin-free P2Y12-inhibitor monotherapy after percutaneous coronary intervention (PCI) is an alternative to dual antiplatelet therapy (DAPT), but the evidence rests largely on full-dose ticagrelor in acute coronary syndrome and on designs retaining a DAPT run-in; East-Asian patients may not require the same antithrombotic intensity. We compared standard DAPT, DAPT with half-dose ticagrelor, and aspirin-free half-dose ticagrelor monotherapy initiated on the day of PCI in chronic coronary syndrome (CCS). Methods: Sixty-one East-Asian patients with CCS scheduled for elective PCI were randomized 1:1:1 to Control (aspirin plus clopidogrel), Experimental A (aspirin plus ticagrelor 45 mg twice daily), or Experimental B (ticagrelor 45 mg monotherapy, aspirin discontinued at day 2). DAPT arms continued for six months; Experimental B continued indefinitely. P2Y12 reaction units (PRU) were measured at baseline and at a median of 17 days. Results: PRU reduction was three-fold greater in both ticagrelor arms than in Control ({Delta}PRU -188 and -181 versus -60.5; P<0.001), with no difference between ticagrelor arms (P=0.772). At 12 months, major adverse cardiovascular events (MACE) and clinically relevant bleeding each occurred in 1 of 17 Experimental B patients (5.9%) and in neither other arm. One Experimental A patient crossed over for ticagrelor-induced dyspnea; no stent thrombosis or cardiac death occurred. Conclusions: In East-Asian patients with CCS, half-dose ticagrelor produced markedly greater platelet inhibition than standard DAPT, with an identical effect whether given with or without aspirin. It merits evaluation in an adequately powered randomized trial. Clinical Trial Registration. URL: https://www.clinicaltrials.gov; Unique Identifier: NCT07622056

Background. Heart failure with preserved ejection fraction (HFpEF) accounts for more than half of heart failure cases and is characterized by substantial clinical and biological heterogeneity. Sex differences are central to HFpEF pathophysiology, yet current phenotyping approaches often aggregate women and men, potentially obscuring distinct molecular mechanisms of disease progression. Molecularly resolved, sex-specific stratification is therefore needed to identify divergent risk pathways and improve biological understanding of HFpEF heterogeneity. Methods. In 698 HFpEF participants from the prospective MyoVasc cohort (379 females, 319 males), we run separate analyses on sex-specific cohorts. For each cohort, we integrated 92 circulating proteins (Olink Inflammation panel) and 49 clinical variables using Similarity Network Fusion to construct sex-stratified patient-patient similarity networks. Spectral clustering identified sex-specific prognostic subgroups related to the primary endpoint, i.e. worsening of Heart Failure (WHF). XGBoost models characterizing cluster-defining features were validated in an independent cohort of 342 HFpEF patients from the Gutenberg Health Study (GHS; 194 females, 148 males). Results. Two clusters emerged in each sex, with high-risk and low-risk clusters, showing the difference in WHF risk (MyoVasc females: HR 2.45, 95% CI 1.32-4.54, p=0.005; males: HR 2.77, 95% CI 1.27-6.04, p=0.011; C-index 0.62-0.63). Kaplan-Meier analyses confirmed separation (p<0.02 females, p<0.01 males). Clusters were reproduced in GHS using MyoVasc-trained XGBoost (females p=0.0082, males p=0.037). Shared top-ranking features included VEGF-A, TNFRSF9, and TGF-. Females were characterized by inflammatory (CD40, HGF, TNF) and glycemic signatures, whereas males showed prominence of immune-regulatory markers (IL-10RB, PD-L1) and renal function indicators (eGFR, creatinine). Conclusions. Sex-stratified molecular-clinical networks define prognostically distinct HFpEF subgroups with robust external validation. Shared protein biomarkers alongside sex-specific drivers reveal complementary progression mechanisms, supporting precision medicine strategies targeting high-risk cluster patients in sex-specific manner.

Cystic fibrosis (CF) is characterized by defective CFTR-mediated chloride transport, resulting in elevated sweat chloride concentrations. As people with CF (PwCF) now live longer due to highly effective CFTR modulators, exercise has become integral to maintaining health, yet it introduces additional physiological demands on salt and fluid balance. In this study, we used a wearable microfluidic biosensor (CF Patch) to quantify sweat rate and chloride loss during exercise performed both in the supervised laboratory and remote free-living in PwCF and healthy volunteers (HV). Participants completed exercise sessions under both conditions, with continuous heart rate monitoring and sweat collection with real-time measurement of sweat characteristics. Sweat volume and chloride concentration were assessed by colorimetric image analysis, enabling estimation of total fluid and chloride loss at the end of each exercise session. PwCF exercised for a longer duration at a lower average heart rate during remote exercise compared to laboratory exercise though exercise volume (average heart rate x duration) was greater during remote exercise. There was a positive association between exercise volume and both fluid and chloride loss for both PwCF and HV. PwCF exhibited greater chloride loss for a given exercise volume compared to HV, though fluid loss was similar. Further, compared to HV, PwCF demonstrated significantly greater intra- and interindividual variability in sweat chloride loss across the remote exercise sessions. Collectively, these findings provide evidence for the feasibility and physiological validity of remote exercise assessment and establish the feasibility and physiological validity of wearable sweat sensing for remote monitoring of fluid and electrolyte dynamics during real-world exercise. In addition, the variability of chloride loss in response to exercise suggests utility of the CF Patch in providing personalized fluid and salt repletion data for PwCF and advances the translational potential of digital sweat diagnostics for personalized CF care.