Circulation

BACKGROUNDAficamten is a next-in-class, oral, selective cardiac myosin inhibitor approved for the treatment of obstructive hypertrophic cardiomyopathy (oHCM). A comprehensive understanding of long-term safety is essential to inform clinical use. OBJECTIVETo assess the integrated safety profile of aficamten across phase 2/3 clinical trials in patients with oHCM. METHODSThis integrated safety analysis pooled data from patients with oHCM who received [&ge;]1 dose of aficamten or placebo/metoprolol in REDWOOD-HCM, SEQUOIA-HCM, MAPLE-HCM, and FOREST-HCM. Safety outcomes included treatment-emergent adverse events (TEAEs), serious TEAEs, adverse events of special interest, occurrences of site-read left ventricular ejection fraction (LVEF) <50%, and echocardiography-guided treatment modifications. Events were summarized descriptively and using exposure-adjusted incidence rates (EAIRs) per 100-patient-years. RESULTSThe cumulative aficamten-treated pool included 463 unique patients, representing 697 patient-years of exposure. Aficamten was well tolerated, with permanent treatment discontinuation occurring in 4 (0.9%) aficamten-treated patients (EAIR 0.6). In the control group pool, rates of TEAEs were comparable between aficamten and placebo/metoprolol, except hypertension was more common in aficamten-treated patients. In the cumulative aficamten-treated pool, LVEF <50% occurred in 19 (4.1%) patients (EAIR 2.8). There were no cases of LVEF <50% associated with clinical heart failure that were attributable to aficamten, and no excursions of LVEF <40%. New-onset atrial fibrillation was uncommon (EAIR 2.4). CONCLUSIONSOver nearly 700 patient-years of exposure, aficamten was well tolerated with a favorable safety profile in patients with oHCM. The rates of clinically relevant systolic dysfunction, atrial fibrillation, and other major cardiovascular events were low and similar to placebo or metoprolol. Clinical trial registrationREDWOOD-HCM (NCT04219826); SEQUOIA-HCM (NCT05186818); MAPLE-HCM (NCT05767346); FOREST-HCM (NCT04848506)

BackgroundCardiovascular and cerebrovascular risks of SARS-CoV-2 infection and mRNA vaccination remain incompletely defined and lacking comparative outcomes such as sex-specific vulnerabilities. MethodsUsing the TriNetX Research Network (December 2020-December 2024), we identified four mutually exclusive cohorts: uninfected/unvaccinated (naive), infected/unvaccinated, vaccinated-only, and infected/vaccinated (hybrid immunity). We compared 50 prespecified cardiovascular, cerebrovascular, and mortality outcomes across four pairwise cohort comparisons, with analyses stratified by sex and time of event windows (0-3, 3- 6, 6-9, and >9months). Different vaccine dosing strategies were analyzed. ResultsAmong 30.3 million individuals, infection was associated with a 4.5-fold increased mortality in males and 4.0-fold in females (p<0.001) as well as marked increases in myocarditis, myocardial infarction, and pulmonary embolism. Inflammatory cardiac complications occurred four times more often after infection than vaccination. Vaccination alone conferred a 76% reduction in major adverse cardiovascular events (MACE) in males and 69% in females, with no detectable cardiovascular toxicity. Post-infection vaccination provided an additional 36-38% MACE reduction, though males with hybrid immunity had a late increased risk of pericarditis. Completing the two-dose vaccine series maximally reduced mortality (by 77%) and myocarditis (by 62%) versus single dosing; further doses gave minimal additional benefit but sustained the benefit of the primary vaccination series. Females had higher infection-linked myocarditis risk despite lower mortality. ConclusionsSARS-CoV-2 infection confers substantially greater and sustained cardiovascular and cerebrovascular risk than mRNA vaccination, confirming a highly favorable benefit-risk profile for vaccination. These findings support extended cardiovascular surveillance after infection and targeted, risk-based vaccination strategies.

Background: Despite optimal lipid-lowering and antithrombotic therapy, substantial residual cardiovascular risk persists in established atherosclerotic cardiovascular disease (ASCVD), partly driven by chronic vascular inflammation. Methods: Systematic review and meta-analysis of RCTs comparing colchicine to placebo or no treatment in adults with established ASCVD. Searches on March 21, 2026 (PubMed, Embase, CENTRAL, ClinicalTrials.gov, WHO ICTRP). PROSPERO CRD420261346516. Primary outcome: 4-point MACE (CV death, MI, stroke, urgent revascularization). DerSimonian-Laird random-effects with HKSJ adjustment. Exploratory trial-level meta-regression: time-to-initiation (TTI) and cumulative dose as continuous moderators. Results: DL pooled HR for 4-point MACE: 0.68 (95% CI 0.51-0.89; p=0.0060). HKSJ-adjusted HR: 0.68 (95% CI 0.27-1.70; p=0.3018). Substantial heterogeneity (I2=81.4%; 95% prediction interval 0.29-1.57, crossing 1.0). Exploratory meta-regression: TTI (beta=-0.00187/day, p=0.003) and cumulative dose (beta=-0.00163/mg-day, p=0.0003; k=5, explicitly underpowered). Non-CV mortality: HR 1.07 (0.76-1.50; p=0.694). GI discontinuation: pooled RR 1.95 (1.09-3.48; p=0.024). GRADE certainty: Moderate (4-point MACE). Conclusions: Low-dose colchicine is associated with reduced 4-point MACE in ASCVD (DL HR 0.68; HKSJ HR 0.68). The substantial heterogeneity and wide prediction interval indicate that effect size varies substantially across clinical settings. The divergence between CLEAR SYNERGY (acute; HR 0.99) and sub-acute/chronic trials (HR 0.33-0.77) drives heterogeneity. Meta-regression suggests TTI and cumulative exposure may be key moderators but is underpowered. The non-CV mortality signal is not confirmed. This analysis informs precision anti-inflammatory prescribing in ASCVD.

BACKGROUND Point-of-care (POC) high-sensitivity cardiac troponin (hs-cTn) testing has the potential to expedite decision-making and reduce emergency department (ED) length of stay for patients presenting with possible myocardial infarction (MI) by ensuring that results are consistently available when looked for by clinicians. We assessed the real-life effectiveness and safety of implementing POC hs-cTn testing in the ED. METHODS We conducted a pragmatic, stepped-wedge cluster randomized trial. The control arm was usual care with an accelerated diagnostic pathway utilizing a single-sample rule-out step with a central laboratory hs-cTn assay. The intervention arm used the same pathway with a POC hs-cTnI. The primary effectiveness outcome was ED length of stay assessed using a generalized linear mixed model, and the safety outcome was 30-day MI or cardiac death. RESULTS Six sites participated with 59,980 ED presentations (44,747 individuals, 61{+/-}19 years, 49.5% female) from February 2023 to January 2025, in which 31,392 presentations were during the intervention arm. After adjustment for co-variates associated with length of stay, the intervention reduced length of stay by 13% (95% confidence intervals [CI], 9 to 16%. P<0.001), corresponding to a reduction of 47 minutes (95%CI, 33 to 61 minutes) from a mean length of stay in the control arm of 376 minutes. The 30-day MI or cardiac death rate was similar in the control and intervention arms (0.39% and 0.39% respectively, P=0.54). CONCLUSIONS Implementation of whole-blood hs-cTnI testing at the POC into an accelerated diagnostic pathway was safe and reduced length of stay in the ED compared with laboratory testing.

BackgroundAmong patients with ST segment elevation myocardial infarction (STEMI), higher concentrations of high sensitivity troponin T (hs-cTnT) are associated with larger MI size and predict a worse prognosis. In the 2467 patient CELEBRATE trial, a single subcutaneous injection of the short-acting glycoprotein IIb/IIIa receptor blocker antagonist zalunfiban at first medical contact significantly improved the primary outcome including clinical endpoints. In this study, we assessed the impact of zalunfiban on MI size and association with downstream outcomes remains unclear. MethodsIn a prespecified analysis, we studied results among study participants treated with two doses of zalunfiban who had core laboratory measurements concentrations of hs-cTnT. ResultsThe median concentration of hs-cTnT at presentation was 62 ng/L; at 24 hours it was 1962 ng/L. More elevated hs-cTnT concentrations at presentation were associated with less resolution of ST deviation after revascularization (P =0.006) and more frequent Q wave development (all P <0.001). At coronary angiography more elevated hs-cTnT at presentation was also associated with higher thrombus grade and worse epicardial and myocardial perfusion (all P <0.05). In multivariable analyses, higher hs-cTnT concentrations at 24 hours were associated with greater adjusted risk for all-cause death (odds ratio [OR] 1.83 per log unit increase; P=0.03), cardiovascular death (OR 1.83 per log unit increase; P=0.03), heart failure (OR 2.74 per log unit increase; P <0.001) or the composite of death (or cardiovascular death) and heart failure (P<0.001) by 30 days. At 24 hours, those treated with zalunfiban had lower hs-cTnT compared to placebo (1900 vs 2082 ng/L; P =0.04) and across multiples [&ge;]10 to [&ge;]1000 times elevation, treatment with zalunfiban resulted in smaller hs-cTnT determined MI size. ConclusionAmong patients with STEMI, higher concentrations of hs-cTnT are associated with worse angiographic and ECG measures of reperfusion. More elevated hs-cTnT predicted a higher risk for short-term death or heart failure. A single dose of zalunfiban at first medical contact reduced MI size, as judged by more study participants with lower hs-cTnT concentrations. These results provide a mechanistic basis for the improved clinical outcomes associated with zalunfiban treatment in the CELEBRATE Trial. Study registrationA Phase 3 Study of Zalunfiban in Subjects With ST-elevation MI (CELEBRATE); NCT04825743

Acute myocardial infarction (MI) is associated with severe metabolic and oxidative stress that triggers cardiomyocyte death, pro-inflammatory signaling and progressive structural remodeling frequently culminating in heart failure. Although significant advances in reperfusion therapy improved acute survival in patients, therapeutic strategies that directly target intracellular processes in response to injury remain limited. One key response mechanism, autophagy, is rapidly activated to ameliorate ischemic stress. Yet, defective autophagic flux may exacerbate cardiomyocyte injury and maladaptive tissue remodeling. Here we identify FYCO1 as a cardiomyocyte- enriched key regulator of autophagy that enhances autophagic flux and promotes myocardial resilience following ischemic injury. Using cardiomyocyte-specific FYCO1 transgenic mice subjected to permanent coronary ligation, we demonstrate that FYCO1 overexpression limits infarct expansion, reduces cardiomyocyte injury, and preserves cardiac function during remodeling. In vivo RFP-EGFP-LC3 autophagy reporter analyses reveal that FYCO1 promotes a sustained increase of autophagic flux by coordinating autophagosome formation and efficient autolysosomal clearance. Transcriptomic profiling identifies a cardioprotective gene program in FYCO1-Tg animals subjected to MI, with suppression of proinflammatory, proapoptotic and stress-response pathways. Systemic serum cytokine and chemokine profiling as well as transcriptomic analyses of myocardium confirm reduced inflammatory signaling and subsequent reduction in macrophage recruitment into the infarct border zone. Together these findings position FYCO1 as a key regulator of cardiomyocyte autophagy and reveal a previously unrecognized link between autophagy and inflammation in shaping cardiac remodeling following myocardial infarction. FYCO1-mediated autophagy promotes myocardial preservation and functional recovery, highlighting autophagic flux as a promising target for cardioprotective interventions.

BackgroundPathogenic desmin (DES) variants have been implicated in early-onset atrial disease, yet the mechanisms by which desmin dysfunction alters atrial structure and function remain unclear. Desmin anchors the cytoskeleton to the nuclear envelope (NE) through the linker of nucleoskeleton and cytoskeleton (LINC) complex, suggesting that defects in this network may drive atrial cardiomyopathy. MethodsHuman desmin wild-type (WT) and the pathogenic variants p.S13F, p.N342D, and p.R454W were stably expressed in HL-1 atrial cardiomyocytes. Desmin organization, nuclear morphology, LINC-complex integrity (nesprin-3, lamin A/C), and DNA leakage, assessed by cyclic GMP-AMP synthase (cGAS), were analyzed by confocal microscopy. Action potential duration (APD) and calcium transients (CaT) were measured optically. Human myocardium samples from DES variant carriers were analyzed for validation. Data-independent acquisition (DIA) mass spectrometry profiled atrial proteomes from desmin-network (DN) and titin variant carriers and controls. The heat-shock proteins (HSPs) inducer geranylgeranylacetone (GGA) was evaluated for rescue effects. Resultsp.N342D caused severe filament-assembly defects with prominent perinuclear aggregates, whereas p.S13F showed mixed phenotypes with frequent perinuclear aggregates, and p.R454W largely preserved filamentous networks. p.N342D and p.S13F induced nuclear deformation with disrupted nesprin-3 and lamin A/C distribution. In p.N342D and p.S13F, desmin aggregates drove focal lamin A/C accumulation, nuclear envelope (NE) rupture, DNA leakage, and increased cGAS activation. DES variants significantly shortened APD20/90 and reduced CaT amplitude, indicating pro-arrhythmic electrical remodeling. Atrial proteomics revealed a DN-specific signature enriched for cytoskeletal, NE, intermediate filament, and chaperone pathways, consistent with the structural injury observed in vitro. GGA prevented desmin aggregation and nuclear morphology changes, and mitigated APD shortening in p.N342D-expressing cardiomyocytes. Human myocardium from DES variant carriers showed concordant desmin aggregation and polarized lamin A/C distribution. ConclusionsDES variants induce a desmin-dependent atrial cardiomyopathy characterized by cytoskeletal disorganization, disruption of LINC-complex, NE rupture with DNA leakage, and pro-arrhythmic electrophysiological remodeling. These findings provide mechanistic insight into how DN variants promote atrial disease. HSPs induction by GGA partially restores structural and functional integrity, identifying a potential therapeutic approach for desmin-related atrial cardiomyopathy. Clinical perspectiveWhat is new? O_LIPathogenic DES variants induce a previously unrecognized atrial cardiomyopathy characterized by desmin aggregation, and desmin-network (DN) collapse, disruption of the linker of nucleoskeleton and cytoskeleton (LINC) complex, and nuclear envelope rupture with DNA leakage. C_LIO_LIVariants that lead to desmin aggregation (e.g., p.N342D) cause focal lamin A/C polarization, cyclic GMP-AMP synthase (cGAS) activation, and structural injury at the nuclear envelope. C_LIO_LIDES variants produce pro-arrhythmic electrical remodeling, including action potential duration shortening and impaired Ca{superscript 2} handling in HL-1 atrial cardiomyocytes. C_LIO_LIAtrial proteomics from DN variant carriers reveals enrichment of pathways related to cytoskeletal, nuclear envelope, intermediate filament, and chaperone, supporting a desmin-dependent remodeling program. C_LIO_LIThe heat-shock protein inducer geranylgeranylacetone (GGA) prevents desmin aggregation, restores nuclear morphology, and mitigates electrical and Ca{superscript 2} handling remodeling. C_LI What are the clinical implications? O_LIThese findings establish DN dysfunction as a distinct cause of atrial cardiomyopathy, providing a mechanistic basis for the association between pathogenic DES variants and atrial arrhythmias, including atrial fibrillation. C_LIO_LINuclear envelope rupture and cytosolic DNA leakage represent new mechanistic evidence which links cytoskeletal injury and atrial arrhythmogenesis. C_LIO_LIIdentifying structural vulnerability in DES variant carriers fosters awareness of genetic counseling for atrial disease, enabling early detection and risk stratification. C_LIO_LIThe protective effects of GGA suggest that restoring proteostasis may be a therapeutic strategy for desmin-related atrial cardiomyopathy and potentially other genetic atrial diseases. C_LI Novelty and significance statementO_ST_ABSNoveltyC_ST_ABSThis study identifies a desmin-dependent atrial cardiomyopathy driven by cytoskeletal aggregation, LINC-complex disruption, and nuclear envelope rupture with DNA leakage. We show that pathogenic DES variants are associated with pro-arrhythmic molecular remodeling and that human atrial proteomics confirm nuclear envelope and cytoskeletal injury as core features. Importantly, the heat-shock protein-inducer GGA rescues structural, molecular, and electrophysiological defects, revealing a modifiable pathway in desmin-mediated atrial disease. SignificanceThese findings provide the first integrated mechanistic explanation linking DN variants to atrial cardiomyopathy. By uncovering nuclear envelope rupture and cGAS activation as key drivers of atrial cardiomyopathy, this work expands the molecular framework for inherited atrial disease and highlights proteostasis enhancement as a potential therapeutic strategy for patients carrying DES and related cytoskeletal variants. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=166 HEIGHT=200 SRC="FIGDIR/small/26348559v1_ufig1.gif" ALT="Figure 1"> View larger version (51K): org.highwire.dtl.DTLVardef@1fb0bfborg.highwire.dtl.DTLVardef@cfc00borg.highwire.dtl.DTLVardef@1493578org.highwire.dtl.DTLVardef@1556b61_HPS_FORMAT_FIGEXP M_FIG C_FIG

BackgroundElevated resting heart rate is associated with increased mortality, but the underlying mechanisms remain incompletely understood. Subclinical myocardial injury (SCMI), defined by a Cardiac Infarction/Injury Score (CIIS) [&ge;]10, represents silent cardiac damage that predicts poor cardiovascular (CV) outcomes and may partially explain this association. MethodsWe analyzed 7,152 participants from NHANES III who underwent ECG recording and were free of cardiovascular disease. Heart rate was categorized as bradycardia ([&le;]50 bpm), normal (>50-<100 bpm), or tachycardia ([&ge;]100 bpm). Mortality was assessed through National Death Index linkage. Logistic and Cox regression models evaluated associations with SCMI and mortality, respectively, and attenuation was assessed by change in hazard ratios after adjusting for SCMI. ResultsSCMI was present in 1,744 (24.3%) participants. Tachycardia was associated with increased odds of SCMI (adjusted OR 2.34, 95% CI 1.42-3.88). Over 13.9 years median follow-up, 2,311 (32.3%) died from all causes and 933 (13.1%) from CV causes. Tachycardia was associated with increased all-cause mortality (HR 3.58, 95% CI 2.63-4.88) and CV mortality (HR 2.05, 95% CI 1.06-3.79). Adjustment for SCMI attenuated the tachycardia-CV mortality association by 8.6% and all-cause mortality by 5%. Bradycardia was not associated with SCMI or mortality. ConclusionThese findings suggest that SCMI partially mediates the heart rate-mortality relationship and that ECG-based assessment of SCMI may enhance risk stratification in individuals with elevated resting heart rate.

Background and AimsAngiotensinogen synthesis inhibitors have shown promising blood pressure-lowering effects in early-stage trials, but their impact on cardiovascular outcomes remains unknown. We investigated associations between genetic variants mimicking angiotensinogen synthesis inhibition and cardiovascular phenotypes. MethodsWe developed a genetic proxy for hepatic angiotensinogen synthesis downregulation comprising AGT variants that lower liver AGT expression (N=1,183) and circulating angiotensinogen levels (N=47,745), selected to mimic the effects of RNA-based angiotensinogen-targeting therapies. Using drug-target Mendelian randomization, we assessed effects on coronary artery disease (210,842 cases, 1,167,328 controls), stroke (110,182 cases, 1,503,898 controls) and heart failure (207,306 cases, 2,151,210 controls), along with vascular endophenotypes and safety outcomes. ResultsMirroring pharmacological angiotensinogen synthesis inhibitors in trials, the AGT genetic instrument was associated with lower systolic (SBP, -0.60 [-0.71;-0.48] mmHg) and diastolic blood pressure (DBP, -0.40 [-0.46;-0.33] mmHg), and higher renin and potassium levels. Genetically proxied angiotensinogen synthesis inhibition was associated with lower odds of coronary artery disease (OR per mmHg SBP reduction: 0.954 [0.937-0.972]), stroke (OR: 0.949 [0.928-0.970]) and heart failure (OR: 0.972 [0.957-0.987]) with effect sizes proportional to the SBP-lowering effects of genetic proxies for other renin-angiotensin-aldosterone system drug classes. We found additional associations with lower burden of atherosclerosis, cerebral small vessel disease, and adverse cardiac remodeling on imaging endophenotypes. Aside from hyperkalemia, we detected no links to major safety concerns, including impaired kidney function. ConclusionsGenetic downregulation of angiotensinogen synthesis is associated with lower cardiovascular disease burden without concerning safety signals, supporting the potential of angiotensinogen inhibitors to reduce cardiovascular risk. Structured graphical abstractO_ST_ABSKey QuestionC_ST_ABSIs there human genetic evidence suggesting that inhibition of hepatic angiotensinogen synthesis can reduce long-term cardiovascular risk? Key FindingGenetically proxied angiotensinogen synthesis inhibition is associated with lower risk of coronary artery disease, stroke and heart failure, as well as favorable effects on cardiac and cerebrovascular pathologies, without raising major safety concerns. Effect estimates were comparable in magnitude to those observed for genetic proxies of approved RAAS-blocking therapies. Take-home MessageHuman genetic evidence supports the hypothesis that angiotensinogen synthesis inhibition may reduce both cardiovascular event risk and chronic subclinical vascular disease burden, providing a strong rationale for prioritizing angiotensinogen inhibitors in cardio- and cerebrovascular outcome trials. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=119 SRC="FIGDIR/small/26347887v1_ufig1.gif" ALT="Figure 1"> View larger version (49K): org.highwire.dtl.DTLVardef@264dd8org.highwire.dtl.DTLVardef@c0c6f6org.highwire.dtl.DTLVardef@46752dorg.highwire.dtl.DTLVardef@1b71c12_HPS_FORMAT_FIGEXP M_FIG Genetically proxied angiotensinogen synthesis inhibition and cardiovascular risk reduction. Graphical overview of the study design. Created in https://www.biorender.com/ AGT: angiotensinogen, pQTL: protein quantitative trait loci, eQTL: expressive quantitative trait loci, LD: linkage disequilibrium, MR: Mendelian Randomization, SBP: systolic blood pressure, DBP: diastolic blood pressure, UKBB: UK Biobank, CAD: coronary artery disease, RAAS: renin-angiotensin-aldosterone system, CVD: cardiovascular disease, ICH: intracerebral hemorrhage, SAH: subarachnoid hemorrhage, cIMT: carotid intima-media thickness, cSVD: cerebral small vessel disease, HF: heart failure, HFrEF: heart failure with reduced ejection fraction, HFpEF: heart failure with preserved ejection fraction, MRI: magnetic resonance imaging, eGFR: estimated glomerular filtration rate, UACR: urinary albumin-to-creatinine ratio, MVP: Million Veteran Program C_FIG

Cardiac fibrosis driven by persistent myofibroblast activation is a major contributor to adverse ventricular remodeling and heart failure. Bromodomain and extra-terminal domain (BET) inhibition reduces fibrosis and hypertrophy in preclinical models, but direct targeting of the BET co-activator BRD4 is limited by family homology and potential systemic toxicity. Sertad4 (SERTA domain containing protein 4) is a BRD4-dependent gene induced in activated cardiac fibroblasts, yet its role in cardiac pathology is unknown. Here, we examined Sertad4 expression and function in human heart failure and in murine myocardial infarction (MI). SERTAD4 protein was increased in left ventricular tissue from heart failure patients compared with non-failing controls. In Sertad4/LacZ reporter mice, MI triggered strong Sertad4 activation localized to the infarct scar and border zone, with minimal expression in remote myocardium; single-nucleus RNA sequencing further demonstrated that Sertad4 expression is predominantly fibroblast-restricted and significantly upregulated after MI. To test causality, we subjected global Sertad4 knockout mice to 28-day left anterior descending coronary artery ligation. Sertad4 deletion attenuated post-MI remodeling, reduced hypertrophy and ventricular dilation, and preserved systolic function. Consistent with improved structure and function, knockout hearts exhibited reduced cardiomyocyte cross-sectional area and decreased expression of fibrosis and hypertrophy associated genes. Together, these findings identify Sertad4 as a fibroblast enriched regulator of pathological remodeling and suggest that targeting Sertad4 may offer a more cell type-selective alternative to direct BET/BRD4 inhibition for limiting cardiac fibrosis and progression to heart failure

BackgroundPreeclampsia is a leading cause of maternal and perinatal morbidity and mortality, and a major contributor to low birth weight. Beta blockers (BB) and calcium channel blockers (CCB) are the most commonly recommended agents to treat hypertension in pregnancy. Yet it remains unknown whether these agents alter the risk of preeclampsia (PE), and if so, whether effects arise through maternal physiology or through direct fetal mechanisms. ObjectivesTo use drug-target Mendelian randomization (MR) to estimate the effects of genetically-proxied inhibition of beta-adrenergic and L-type calcium-channel targets on PE risk, birth weight, partitioned into maternal and fetal genetic components, and gestational age (GA). MethodsWe constructed instruments from genome-wide significant, LD-independent variants within prespecified windows around systolic blood pressure (SBP) modulating drug targets in addition to a genome-wide SBP instrument (European ancestry). Outcomes comprised of PE (16,349 cases / 595,135 controls), maternal and fetal genetic effects on birth weight (n{approx}210,267 and n{approx}298,142), and GA (n{approx}151,987). Two-sample MR estimated effects per 5mmHg decrease in SBP. Bayesian colocalization assessed shared causal variants. Multiple testing was controlled with Benjamini-Hochberg correction. ResultsGenetically lower SBP was associated with reduced PE risk and modest increases in birth weight and GA. BB (ADRB1) target inhibition showed no convincing reduction in PE risk but was associated with lower birth weight, with associations predominantly through direct fetal genetic effects and strong colocalization at ADRB1 with fetal birth-weight signals. In contrast, CCB targets collectively associated with lower PE risk without consistent evidence of fetal growth impairment; colocalization support for individual CCB loci was limited. Sensitivity analyses (heterogeneity, pleiotropy) did not materially alter these patterns where instrument counts permitted. ConclusionsDrug-target MR suggests that BB pathways are unlikely to meaningfully reduce PE and are linked to reduced fetal growth - chiefly via direct fetal mechanisms. In contrast, CCB pathways are associated with lower PE risk and largely neutral fetal growth effects. These findings support prioritizing CCBs for evaluation in comparative trials of PE prevention.

BACKGROUNDExcessive trabeculations and myocardial crypts are recurrent features across cardiomyopathies, yet their developmental origins and clinical significance remain poorly defined. To reveal the link between cardiac morphogenesis and disease, we generated humanized mouse models carrying patient-derived MYBPC3 frameshift mutations associated with overlapping hypertrophic cardiomyopathy (HCM) and left ventricular non-compaction (LVNC). METHODSWe applied CRISPR-Cas9 to introduce distinct MYBPC3 frameshift alleles into the mouse genome and performed comprehensive phenotypic and transcriptomic profiling from fetal life through adulthood. RESULTSAdult homozygous Mybpc3 frameshift mutant mice like humans displayed hallmark HCM; however, without LVNC. Fetal and neonatal mutant hearts exhibited markedly enlarged ventricular trabeculae and crypts that progressed postnatally into the observed adult hypertrophy. Transcriptomic analysis revealed stage-specific dysregulation of oxidative metabolism, nonsense-mediated decay (NMD), and cell cycle pathways, peaking at postnatal days 1 and 7, indicating that these stages represent critical time points in disease onset. The persistent NMD signature, also observed in phenotype-negative heterozygotes, suggests a compensatory stress response. Enlarged trabeculae exhibited 2-fold increased trabecular cardiomyocyte proliferation, reversing the normal compact-trabecular proliferative gradient and leading to impaired ventricular compaction in neonates. Hey2CreERT2 lineage tracing demonstrated invasion of Hey2+ compact cardiomyocytes into the trabeculae and ectopic trabecular expression of the Prdm16 transcription factor, indicating defective ventricular wall patterning and maturation. Postnatally, Hey2+-derived cardiomyocytes became restricted to the outer/compact myocardium in mutants, while the inner/trabecular myocardium underwent accelerated hypertrophy concurrent with Prdm16 downregulation. Mice with a Mybpc3 missense variant also exhibited Hey2+ myocardial lineage expansion into trabeculae but no increased proliferation, implicating additional mechanisms beyond Hey2 regulation. Postnatal Prdm16 restoration, via transgenic expression in Mybpc3-null mice effectively attenuated hypertrophy, establishing a causal link between Mybpc3 loss, Prdm16 decline, and pathological remodeling. CONCLUSIONSMybpc3 governs ventricular wall maturation by regulating cardiomyocyte proliferation, patterning, and maturation, partly via Prdm16. Disruption of these developmental programs precedes and drives adult HCM, highlighting a developmental role for sarcomeric proteins, and revealing postnatal Prdm16 modulation as an antihypertrophic therapeutic strategy.

BACKGROUNDPeak oxygen uptake (pVO2) is a strong, independent predictor of adverse cardiovascular outcomes, supporting cardiopulmonary exercise testing as a primary end point assessing efficacy of novel drug therapies in obstructive hypertrophic cardiomyopathy (oHCM) clinical trials. However, characterizing changes in pVO2 that patients perceive as beneficial or meaningful (ie, minimal important difference [MID]) has not been determined. METHODSData from patients with symptomatic oHCM enrolled in SEQUOIA-HCM and MAPLE-HCM were pooled. A total of 282 patients were randomized 1:1 to aficamten (5-20 mg daily) or matching placebo in SEQUOIA-HCM, and 175 patients were randomized 1:1 to aficamten (5-20mg daily) or to metoprolol (50-200 mg) in MAPLE-HCM; follow-up in both trials was 24 weeks. Primary outcome was change from baseline to week 24 ({Delta}) in pVO2 using Patient Global Impression of Change with anchor-based analysis to define MID. RESULTSAt week 24, {Delta}pVO2 (mL/kg/min) that corresponded to no change, one-category improvement, and one-category worsening were -0.05 (95% CI, -0.58 to 0.48), +0.35 (95% CI, -0.22 to 0.91), and -0.61 (95% CI, -1.36 to 0.13), respectively. Similarly, minute ventilation to carbon dioxide production ratio (VE/VCO2) slope that corresponded to no change, one-category improvement, and one-category worsening were 0.16 (95% CI, -0.59 to 0.90), -1.15 (95% CI, - 1.89 to -0.42), and 0.88 (95% CI, -0.42 to 2.19), respectively. In a responder analysis using this new threshold for pVO2, 60% of patients receiving aficamten achieved a {Delta}pVO2 [&ge;]0.35 versus 31% of patients on placebo or metoprolol (odds ratio, 3.4 [95% CI, 2.3-4.9], P<0.001). Consistent findings were seen with VE/VCO2 responder analysis. CONCLUSIONSChanges in pVO2 of +0.35 and -0.61 mL/kg/min were associated with a small but perceptible clinical improvement and worsening, respectively, in patients with oHCM. Applying this newly defined threshold resulted in excellent differentiation of treatment effect in a clinical trial. These novel data provide a measure of clarity to patients and clinicians regarding the interpretation of changes in pVO2 following therapeutic interventions, with potential impact on HCM management strategies and future clinical trials. Clinical Trial RegistrationSEQUOIA-HCM (NCT05186818; https://clinicaltrials.gov/study/NCT05186818?term=sequoia-hcm&rank=1); MAPLE-HCM (NCT05767346; https://clinicaltrials.gov/study/NCT05767346?term=maple-hcm&rank=1) Clinical PerspectiveO_ST_ABSWhat Is New?C_ST_ABSO_LIUsing pooled data from over 440 patients with symptomatic obstructive hypertrophic cardiomyopathy enrolled in two phase 3 clinical trials, we define, for the first time, the minimally important difference for peak oxygen uptake (pVO2) and ventilatory efficiency (VE/VCO2) using patient-anchored and distribution-based methodologies. C_LIO_LIA change in pVO2 of +0.35 mL/kg/min and a change in VE/VCO2 of -1.15 represent the minimal thresholds associated with patient-perceived clinical improvement. C_LIO_LIResponder analyses using these thresholds demonstrated robust differentiation between aficamten and placebo/metoprolol, with an odds ratio exceeding 3 for achieving a meaningful improvement in pVO2. C_LI What Are the Clinical Implications?O_LIThese newly defined thresholds bridge the gap between statistically significant changes in cardiopulmonary exercise testing measures and clinically meaningful benefit as perceived by patients with obstructive hypertrophic cardiomyopathy. C_LIO_LIClinicians can use these benchmarks to contextualize individual patient responses to medical therapy, informing shared decision-making regarding treatment continuation or modification. C_LIO_LIThese data provide a standardized, patient-centered framework for designing and interpreting primary end points in future hypertrophic cardiomyopathy clinical trials. C_LI

BackgroundArrhythmogenic cardiomyopathy (ACM) is a heritable nonischemic cardiomyopathy and a leading cause of sudden cardiac death. Although inflammation is a pathological hallmark of ACM, the contribution of peptidylarginine deiminase 4 (PAD4)-dependent neutrophil extracellular trap (NET) formation and myeloperoxidase (MPO) to disease progression remains poorly defined. MethodsTo define the role of PAD4-dependent NETosis and MPO signaling in ACM disease progression homozygous desmoglein-2 mutant (Dsg2mut/mut) mice were utilized. We employed genetic and pharmacological approaches to determine the efficacy of targeting PAD4 and MPO on cardiac function, arrhythmogenic burden, myocardial fibrosis, inflammatory signaling, and gap junction integrity. Cardiac phenotyping included echocardiography, electrocardiography, histology, inflammatory profiling, and biochemical assays. ResultsMarkers of PAD4-dependent NETosis were elevated in Dsg2mut/mut hearts as early as 4 weeks of age, prior to cardiac dysfunction. Genetic deletion of Pad4 significantly preserved left ventricular function, reduced ectopics, attenuated myocardial fibrosis, and suppressed proinflammatory and profibrotic cytokines. MPO levels were increased in Dsg2mut/mut hearts, and genetic ablation of Mpo preserved cardiac function, reduced arrhythmic burden, prevented myocardial fibrosis, and restored connexin-43 phosphorylation and localization. Furthermore, pharmacological MPO-inhibition improved cardiac function, reduced arrhythmias, and attenuated inflammatory signaling, though myocardial fibrosis was not fully prevented. Notably, hearts from patients with ACM demonstrated increased MPO signal in both cardiomyocytes and non-cardiomyocyte populations compared with donor controls. ConclusionsPAD4-dependent NETosis and MPO signaling are key drivers of inflammation, fibrosis, and arrhythmogenesis in early disease onset in ACM. Targeting neutrophil-mediated pathways represents a promising therapeutic strategy to mitigate disease progression in ACM. Clinical PerspectiveO_ST_ABSWhat Is New?C_ST_ABSO_LIPAD4-dependent NET formation is activated early in ACM and directly contributes to myocardial inflammation, fibrosis, arrhythmias, and cardiac dysfunction. C_LIO_LIGenetic ablation of Pad4 or Mpo preserves cardiac function, reduces arrhythmogenic burden, and attenuates proinflammatory and profibrotic signaling in a Dsg2 mutant model of ACM. C_LIO_LIPharmacological inhibition of MPO improves cardiac function and electrical stability, identifying neutrophil-derived pathways as modifiable drivers of disease. C_LI What Are the Clinical Implications?O_LINeutrophil-mediated inflammation represents a clinically relevant mechanism in ACM that may be targeted without global immunosuppression. C_LIO_LIMPO inhibition may offer a novel disease-modifying strategy to reduce arrhythmias and preserve cardiac function in patients with ACM. C_LIO_LINeutrophil- and NET-associated biomarkers may improve early risk stratification and therapeutic decision-making in genetically susceptible individuals. C_LI Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=112 SRC="FIGDIR/small/718596v1_ufig1.gif" ALT="Figure 1"> View larger version (37K): org.highwire.dtl.DTLVardef@54ea46org.highwire.dtl.DTLVardef@e0a417org.highwire.dtl.DTLVardef@350c83org.highwire.dtl.DTLVardef@c879e6_HPS_FORMAT_FIGEXP M_FIG C_FIG (A) Signaling pathway for PAD4-dependent NETosis. (B) Illustration of neutrophil undergoing NETosis resulting in the release of MPO and DNA histone complexes. (C) Effects of MPO release on cardiac tissue of ACM mice

BackgroundCalcium release deficiency syndrome (CRDS) is a recently described inherited channelopathy caused by loss-of-function variants in RYR2. Clinically, CRDS patients present with lethal ventricular arrhythmias which are not reproduced on exercise stress testing, unlike catecholaminergic polymorphic ventricular tachycardia. A hallmark trigger identified for CRDS mimics a long-burst, long-pause, short-coupled extra-stimulus (LBLPS) programmed electrical stimulation protocol, which was experimentally validated in humans and mouse models. Moreover, application of a long-burst, long-pause (LBLP) protocol alone can induce an abnormal repolarization on the first sinus beat that is unique to CRDS. However, the electrophysiological basis of CRDS in human cardiac tissue, including other triggers, are not fully understood, and whether clinically relevant arrhythmias can be observed in human stem cell models remains unknown. MethodsWe performed electrophysiological and arrhythmia inducibility studies using clinically relevant programmed electrical stimulation protocols in two-dimensional cardiac tissue generated from metabolically matured human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) carrying the CRDS variant RyR2-E4146D. High spatiotemporal optical mapping and multielectrode arrays were used for electrophysiological phenotyping. ResultsAt baseline, E4146D+/- monolayers showed no arrhythmias, similar to controls. During rapid pacing, E4146D+/- promoted electrical vulnerability by reducing the threshold for action potential duration (APD) alternans and Ca2+ alternans and increasing the propensity for spatial discordance of alternans. In response to LBLP pacing, E4146D+/- monolayers often demonstrated an abnormal repolarization response characterized by spatially dispersed APD prolongation and large Ca2+ release. Notably, LBLPS pacing produced early-after depolarization (EAD)-driven triggered activity resulting in re-entrant tissue conduction patterns, explaining the short-coupled ectopy driven arrhythmias seen in CRDS patients. Similar arrhythmias were observed when EADs developed during spatially discordant alternans. Lastly, flecainide showed efficacy in suppressing arrhythmia inducibility for the here studied variant. ConclusionsWe developed the first hiPSC model for CRDS which recapitulates clinically observed and inducible arrhythmias. Our model provides novel insights into tissue-level, re-entrant arrhythmias, which are initiated by EADs during electrically vulnerable states in CRDS human cardiac tissue and can be suppressed by flecainide. This model provides the framework for studying other CRDS variants and complex arrhythmias in hiPSC-CMs and establishes a human-based new approach method (NAM) for drug and gene therapy development for CRDS. CLINICAL PERSPECTIVEO_ST_ABSWhat is new?C_ST_ABS{blacksquare} We developed the first human stem cell-derived cardiomyocyte (hiPSC-CM) tissue model for calcium release deficiency syndrome (CRDS) which recapitulates its hallmark clinical features, including inducible ventricular arrhythmias with programmed electrical stimulation and post-pacing repolarization abnormalities. {blacksquare}Using genome edited and metabolically matured hiPSC-CMs combined with high spatiotemporal optical mapping, we show that tissue-level arrhythmias are initiated by early-after depolarizations (EADs) which develop during electrically vulnerable states, leading to re-entrant conduction patterns. We comprehensively characterize the features of EAD-induced triggered activity, showing that these ectopic beats promote re-entry through slower conduction velocities and shorter action potential durations. This uncovers how EAD-induced short-coupled ectopy leads to malignant ventricular arrhythmias in CRDS patients, and establishes the phenotype for future hiPSC-CM investigations. {blacksquare}We identified flecainide as an effective agent in suppressing arrhythmias on single cell and tissue levels in hiPSC-CMs for this CRDS variant, reproducing clinical results. What are the clinical implications?{blacksquare} CRDS has only recently been described as a unique channelopathy caused by loss-of-function RYR2 variants, and much of its triggers and mechanisms in human cardiomyocytes remain unclear. The arrhythmias observed are often not related to exercise, and exercise stress testing does not reproduce these abnormalities. No human models exist to date which closely recapitulate the triggers shown to induce tissue-level arrhythmias in patients and mouse models. Our model demonstrates that programmed electrical stimulation, without pharmacological {beta}-adrenergic stimulation, can reliably induce the same arrhythmias seen clinically, enabling accurate disease modeling and drug development. {blacksquare}Combining programmed electrical stimulation in cardiac tissue derived from genome-edited hiPSC-CMs with high spatiotemporal optical mapping is a robust and novel approach to identify the mechanisms of complex, tissue-level arrhythmias which remain underexplored, such as short-coupled ventricular fibrillation, in a patient-specific and translational manner.

BackgroundElevated resting heart rate (HR) and atrial cardiopathy are each linked to higher mortality risk, yet their interrelationship and joint prognostic value remain unclear. MethodsWe analyzed 7,326 adults (mean age 59 {+/-} 13 years) without cardiovascular disease from the Third National Health and Nutrition Examination Survey with available electrocardiograms. Atrial cardiopathy was defined by electrocardiogram as abnormal P-wave axis or deep terminal P-wave negativity in V1. Multivariable logistic regression assessed cross-sectional associations between HR categories and atrial cardiopathy. Cox proportional hazards models evaluated independent and joint associations of HR categories and atrial cardiopathy with all-cause mortality. ResultsAtrial cardiopathy was present in 1,833 participants (13.5%). After adjustment, sinus tachycardia ([&ge;]100 bpm) was associated with higher odds of atrial cardiopathy (OR 1.76, 95% CI 1.06-2.92), whereas sinus bradycardia ([&le;]50 bpm) was associated with lower odds (OR 0.61, 95% CI 0.43-0.84). Each 10-bpm HR increase corresponded to 25% higher odds of atrial cardiopathy. Over a median 13.8-year follow-up, 2,415 deaths (33.0%) occurred. Sinus tachycardia (HR 3.58, 95% CI 2.61-4.91) and atrial cardiopathy (HR 1.27, 95% CI 1.16-1.39) were independently associated with mortality. Individuals with both conditions had the highest risk (HR 4.11, 95% CI 2.63-6.41). Associations varied by age and race. ConclusionsElevated resting HR is associated with higher odds of atrial cardiopathy, and their coexistence confers markedly increased mortality risk. Integrating resting HR into atrial cardiopathy metrics may enable granular population-level risk profiling.

AbstractO_ST_ABSBackgroundC_ST_ABSGuidelines recommend that patients with coronary artery disease (CAD) lower their low-density lipoprotein cholesterol (LDL-C) using maximally tolerated statin therapy to prevent recurrent events. MethodsWe analyzed the prevalence of statin nonuse and an LDL-C [&ge;]70 mg/dL in patients [&ge;]18 years of age in the Get With The Guidelines-CAD registry with known CAD who were hospitalized for a new myocardial infarction or unstable angina in 2023-2024. Data collection on statin use and LDL-C at arrival is optional in the registry. ResultsAmong 34,003 patients included (mean age 68 years; 71% male; 73% white), 31.6% did not use a statin before admission. The prevalence of statin nonuse was higher in women than in men (adjusted prevalence ratio [aPR] 1.08; 95% confidence interval [95%CI] 1.04, 1.14). LDL-C was not documented in 30.7% of patients. Among patients not using and using a statin, 74.6% and 49.8%, respectively, had an LDL-C [&ge;]70 mg/dL. Women were more likely than men to have an LDL-C [&ge;]70 mg/dL, whether using or not using a statin (aPR 1.18 [95%CI 1.13, 1.24] and 1.08 [95%CI 1.04, 1.12], respectively). Black and Hispanic patients were more likely to have an LDL-C [&ge;]70 mg/dL compared to their white counterparts (aPR 1.30 [95%CI 1.24, 1.37] and 1.11 [95%CI 1.03, 1.19], respectively) among those using a statin. There were no statistically significant differences in LDL-C by race/ethnicity among those not using a statin. ConclusionTargeted quality improvement initiatives are needed to address ambulatory cholesterol treatment gaps in patients with known CAD. Clinical PerspectiveO_ST_ABSWhat Is New?C_ST_ABSO_LIIn a contemporary national registry of patients with known coronary artery disease hospitalized for recurrent acute coronary syndromes, about one-third were not using statin therapy prior to admission. C_LIO_LIApproximately three-quarters of statin nonusers and one-half of statin users had an LDL-C level [&ge;]70 mg/dL at admission, indicating substantial residual risk despite current guideline recommendations. C_LIO_LIWomen and Black and Hispanic patients were more likely to have inadequately controlled LDL-C, particularly among those already receiving statin therapy. C_LI What Are the Clinical Implications?O_LIPreventable ambulatory cholesterol treatment gaps frequently occur before recurrent coronary events, underscoring the need for more guideline-recommended outpatient lipid management. C_LIO_LIRoutine LDL-C monitoring and timely intensification of lipid-lowering therapy, including high-intensity statins and add-on therapies when indicated, should be prioritized after coronary events. C_LIO_LITargeted quality improvement strategies in the ambulatory setting are needed to address persistent cholesterol treatment gaps in secondary prevention care, including sex- and race/ethnicity-related disparities. C_LI

Background and AimsDespite advances in reperfusion and medical therapy, survivors of acute myocardial infarction (AMI) remain at risk for adverse left ventricular remodeling (LVR), a precursor to heart failure. Building on prior work outlining 12-month biomarker trajectories linked to early ventricular dysfunction, we aimed to assess whether these circulating biomarkers predict long-term adverse LVR. MethodsWe prospectively enrolled 155 patients experiencing their first AMI. Clinical, biochemical, and echocardiographic data were obtained at pre-percutaneous coronary intervention (pre-PCI), 24 h post-PCI, discharge (day 3), 6 months, and 12 months. Adverse LVR was defined as an increase of [&ge;]15 % in left ventricular end-systolic volume at 12 months. ResultsAdverse LVR occurred in 34 % of patients and was associated with cardiometabolic dysregulation (higher glucose, triglycerides, BMI, HOMA-IR; lower HDL-C). Among the six baseline biomarkers, only insulin-like growth factor-binding protein 2 (IGFBP-2) differed significantly between groups (p = 0.021) and remained independently associated in multivariable analysis (p = 0.036). Inclusion of IGFBP-2 increased the predictive models area under the receiver-operating characteristic curve from 0.735 to 0.801. ConclusionsIGFBP-2 is an independent predictor of adverse LVR following AMI, highlighting the interplay between metabolic dysfunction and maladaptive remodeling. Incorporating IGFBP-2 into clinical risk models could improve stratification and guide precision therapies for high-risk patients.

BackgroundLong-term electrocardiogram (ECG) monitoring with wearable devices enables large-scale characterisation of cardiac rhythms, but population-based evidence remains limited. The UK Biobank Cardiac Monitoring Study integrates 14-day patch-based ECG monitoring with accelerometry and detailed phenotypic and lifestyle data. Here, we report the acquisition protocol, data processing, and initial findings from 27,658 participants. MethodsParticipants in the UK Biobank imaging study were invited to undergo 14-day cardiac monitoring using a Zio XT (pilot phase; 2015-18) or BodyGuardian MINI (main phase; 2019- ongoing) monitor. ECGs were analysed by certified technicians and automated algorithms to identify atrial, ventricular, and conduction arrhythmias. In parallel, beat-to-beat RR intervals were derived using in-house algorithms, and physical activity from calibrated triaxial accelerometer data. Analyses assessed wear time, arrhythmia prevalence, circadian patterns, and repeatability. FindingsIn total, 27,658 participants (mean age 71 years; 49.9% women) were analysed, including 7,795 from the pilot phase and 21,141 from the main phase; 1,353 (4.9%) had repeat recordings. In the main phase, median wear time was 13.2 days (IQR 11.9-13.9), and undiagnosed atrial fibrillation (AF) was detected more frequently in men than women (3.2% vs 1.7%; p<0.001); 68% was paroxysmal, with 27.4% detected during week two. Ventricular tachycardia occurred in 12.1% (8.4% in women), with sustained episodes rare (0.4%) but observed. Arrhythmia timing varied markedly with activity, with AF peaking during nocturnal inactivity and ventricular ectopy increasing during activity, peaking at midday. Repeat assessments showed strong reproducibility of diurnal heart rate and activity profiles, with more modest arrhythmia consistency. InterpretationExtended ECG monitoring enables detection of subclinical arrhythmias and long-term physiological rhythms in older adults. Linkage to imaging, multi-omics, and clinical outcomes in UK Biobank will enable unprecedented evaluation of the natural history of asymptomatic rhythm disturbances and their impact on brain health. FundingBritish Heart Foundation and Wellcome Trust.

BackgroundAcute heart failure (AHF) exhibits marked heterogeneity in diastolic hemodynamics, yet comprehensive echocardiographic assessment of diastolic function (DF) and filling pressure (FP) is often infeasible. We evaluated whether artificial intelligence-enabled electrocardiography (AI-ECG) could provide scalable DF grading and FP estimation in hospitalized AHF patients. MethodsWe retrospectively studied adults hospitalized for AHF across Mayo Clinic sites (2013-2023) who received [&ge;]1 dose of intravenous loop diuretic and had paired 12-lead ECG and TTE. The previously validated AI-ECG DF model was applied without retraining to generate four DF grades and a continuous FP probability. Clinical outcomes were all-cause mortality and heart failure rehospitalization. Associations with clinical severity markers and echocardiographic indices were examined. Kaplan-Meier survival analysis and adjusted multivariable Cox proportional hazards models were performed. Exploratory analyses examine the kinetics of change in FP probability and impact on mortality. ResultsAmong 11,513 patients (median age 75 years, 39% female), AI-ECG DF grading was feasible in 100%, whereas echocardiographic DF was indeterminate in 44% of clinically eligible patients. In 2,582 patients with determinate echocardiographic DF, AI-ECG FP probability discriminated TTE Grade 2-3 dysfunction with AUC 0.85 (95% CI 0.83 - 0.86). Higher AI-ECG DF grades were associated with higher comorbidity burden, worse NYHA class, elevated NT-proBNP, higher MAGGIC scores, elevated PCWP, and more advanced structural remodeling. After multivariable adjustment, AI-ECG DF remained independently associated with mortality (hazard ratio [HR] 1.25, 95% CI 1.16-1.35 for Grade 2; HR 1.44, 95% CI 1.33-1.56 for Grade 3 versus Normal/Grade 1). Combining AI-ECG DF with MAGGIC scores yielded ordered risk gradients, with highest mortality in patients with both high MAGGIC and Grade 2-3 DF. Among patients with serial ECGs, improvement in FP probability was independently associated with lower mortality (HR 0.85, 95% CI 0.79-0.91), whereas worsening did not show a consistent adverse gradient beyond baseline DF. ConclusionsIn a large, geographically diverse AHF cohort, AI-ECG DF grading was universally feasible, correlated with established hemodynamic severity markers, and provided independent prognostic information beyond established risk factors, supporting its role as a pragmatic, scalable diastolic biomarker in AHF. CLINICAL PERSPECTIVEO_ST_ABSWhat Is New?C_ST_ABSO_LIIn 11,513 hospitalized acute heart failure (HF) patients, artificial intelligence-enabled electrocardiography provided diastolic function grading in 100% of patients from a single 12-lead ECG without requiring additional clinical variables, compared with 56% feasibility for guideline-based echocardiography grading. C_LIO_LIAI-ECG diastolic function grades correlated with established marker of severity (NYHA functional class, NT-proBNP, MAGGIC risk scores, and pulmonary capillary wedge pressure) and remained independently associated with both mortality and HF rehospitalization after multivariable adjustment. C_LIO_LISerial AI-ECG measurements identified post-discharge filling pressure trajectories, with improvement independently associated with 15% lower mortality, a first demonstration that longitudinal ECG assessment can track post-discharge hemodynamic recovery. C_LI What Are the Clinical Implications?O_LIAI-ECG transforms the universally obtained 12-lead ECG into an actionable hemodynamic biomarker that addresses the critical gap when echocardiographic diastolic function assessment is indeterminate or unavailable in acute HF patients. C_LIO_LIDespite markedly different hemodynamic severity and long-term outcomes across AI-ECG diastolic function grades, hospitalization length of stay did not differ, suggesting advanced diastolic dysfunction represents occult risk not easily recognized during routine acute care and highlighting the need for improved post-discharge risk stratification. C_LIO_LIThe continuous filling pressure probability metric enables longitudinal monitoring of post-discharge hemodynamic status using serial routine ECGs, potentially identifying patients requiring intensified follow-up or specialist referral. C_LI