Journal of the American College of Cardiology

BackgroundMyocardial 18fluorodeoxyglucose (18FDG)-avidity is frequently seen in patients with genetic cardiomyopathy (CMP), as well as a growing "idiopathic 18FDG-avidity" group of genotype-negative patients who do not clearly have cardiac sarcoidosis (CS). ObjectivesTo determine the prognostic implications of 18FDG-avidity in patients with and without genetic CMP, and the effects of immunosuppression in the latter. MethodsThis multicenter, retrospective study included all patients who were referred for both 18FDG-PET and CMP genetic testing. Patients with acute myocarditis, biopsy-proven sarcoidosis or extracardiac 18FDG-avidity were excluded. We investigated heart failure (HF) composite (left ventricular assist device, heart transplant, HF hospitalization, death) and arrhythmia composite (sustained ventricular arrhythmias (VT/VF), atrio-ventricular block, death) outcomes using survival analysis including Cox proportional hazards modeling and inverse probability of treatment weighting (IPWT). ResultsAmong 372 patients, 142 (38%) were 18FDG-avid. Prevalence of genetic CMP among 18FDG-avid patients (12%) was similar to that of 18FDG-negative patients (19%, p=0.07). 18FDG-avidity was associated with increased risk of HF composite (HR 1.69 (1.04-2.75), p=0.034) and arrhythmia composite (HR 1.63 (1.1-2.4), p=0.014) outcomes compared to 18FDG-negative patients. However, these associations were present only in genotype-negative patients, and not in genetic CMP. After IPWT, immunosuppression of 18FDG-avid patients (n=49) was not associated with a reduction in HF (HR 3.31 (1.25, 8.77), p=0.016) or arrhythmia composite outcomes (HR 1.61 (0.79, 3.25), p=0.19) compared with those who were not immunosuppressed (n=93). ConclusionsMyocardial-only 18FDG-avidity is only associated with adverse HF and arrhythmia outcomes in genotype-negative patients who do not clearly have CS. IST does not seem to modify the disease course, suggesting that not all myocardial 18FDG uptake reflects clinically significant inflammation.

We performed a systematic review and meta-analysis of randomized controlled trials evaluating glucagon-like peptide-1 receptor agonists (GLP-1 RAs) versus placebo in adults with heart failure (HF), searching PubMed, Cochrane CENTRAL, and ClinicalTrials.gov through February 2026. The primary outcome was the composite of cardiovascular death and first HF hospitalization. Random-effects meta-analysis used restricted maximum likelihood estimation with Hartung-Knapp-Sidik-Jonkman adjustment. We included 14 studies (6 dedicated HF trials and 8 cardiovascular outcomes trial HF subgroup analyses) encompassing 18,558 patients, of whom 2,499 were randomized in dedicated HF trials. The primary composite did not reach statistical significance (hazard ratio [HR] 0.86, 95% confidence interval [CI] 0.73-1.01; P=0.067; I2=47%). GLP-1 RAs significantly reduced all-cause mortality (HR 0.87, 95% CI 0.81-0.93; P<0.001; I2=0%), major adverse cardiovascular events (HR 0.83, 95% CI 0.73-0.95; P=0.019), and improved Kansas City Cardiomyopathy Questionnaire Clinical Summary Score (+7.4 points, 95% CI 6.3-8.5) and 6-minute walk distance (+17.6 m, 95% CI 13.4-21.7). Excluding the FIGHT trial (acute HFrEF) yielded a significant primary composite (HR 0.83, P=0.011). The mortality signal was driven primarily by CVOT subgroups; the largest dedicated HFpEF trial (SUMMIT) showed numerically higher mortality (HR 1.25). The strongest evidence supports GLP-1 RAs in HFpEF with obesity. HighlightsO_LIPrimary composite of CV death + HHF was not significant (HR 0.86, P=0.067) C_LIO_LIGLP-1 RAs reduced all-cause mortality (HR 0.87) with no heterogeneity C_LIO_LIKCCQ-CSS improved by 7.4 points and 6MWD by 17.6 m in HFpEF trials C_LIO_LIMortality benefit driven by CVOT subgroups, not dedicated HF trials C_LIO_LIStrongest evidence supports GLP-1 RAs in HFpEF with obesity C_LI

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

Background Current management of pediatric dilated cardiomyopathy (DCM) in children relies on guideline-directed medical therapy (GDMT) extrapolated from adult heart failure. However, due to small sample size, randomized trials of GDMT agents in children have failed to demonstrate efficacy and mortality benefits seen in adults, suggesting fundamental differences in disease mechanisms. We hypothesized that distinct age-dependent transcriptional programs underlie this therapeutic discordance. Methods We performed comparative transcriptomic profiling using bulk RNA sequencing on explanted left ventricular tissue from pediatric (n=29) and adult (n=35) DCM patients (adult DCM from previously published data) compared with age-matched non-failing controls (n=22 pediatric, 14 adult). We analyzed differential gene expressions, pathway enrichment across disease etiologies, and the regulation of a conserved 430-gene {beta}1-adrenergic receptor gene signaling network ({beta}1-GSN) known to modulate remodeling in adult heart failure. Results Transcriptional signatures were profoundly distinct, with only 7.4% of differentially expressed genes shared between adult and pediatric cohorts. Pediatric DCM was characterized by transcriptional reprogramming and the activation of developmental pathways, including WNT/{beta}-catenin and Notch signaling. Conversely, adult DCM hearts were enriched for pathways associated with metabolic dysfunction, mitochondrial deficits, and inflammation. Crucially, while the {beta}1-GSN was desensitized and extensively remodeled in adults, the pathway remained activated in children, with only 4 of 430 network genes showing antithetical regulation. Conclusion The lack of pathological {beta}-adrenergic remodeling in children could provide a molecular explanation for the lack of clear efficacy of {beta}-blockers in this population. Collectively, these results suggest pediatric DCM represents a biologically distinct disease entity rather than an earlier manifestation of adult heart failure, and future therapeutic strategies must move beyond adult extrapolation to target pediatric-specific pathways.

BackgroundGenetic studies using cardiac magnetic resonance (CMR) imaging have identified loci related to cardiac shape, but most focus on static morphology. The value of a dynamic cardiac shape atlas capturing both shape and function remains unknown. MethodsA dynamic shape atlas comprising CMR-derived shape models at end-diastole and end-systole was combined with genetic and outcome data in 36,992 UK Biobank participants. Dynamic shape principal components (PCs) describing >1% of variance were characterized, and tested for associations with prevalent and incident cardiometabolic diseases, including ischemic heart disease (IHD), heart failure (HF), significant atrioventricular block (AVB), and atrial fibrillation (AF), and independent predictive power alongside standard CMR measures. Genome-wide association studies (GWAS) were performed to identify candidate genes and biological pathways, and polygenic risk scores (PRS) were assessed for disease associations. Mendelian randomization (MR) was performed to test causality of observed disease associations. ResultsWe identified 14 dynamic cardiac shape PCs capturing 83.3% of total dynamic cardiac shape variance. These PCs captured distinct functional remodeling patterns such as variation in annular plane systolic excursion, while remaining only modestly correlated with standard CMR measures. All 14 PCs were associated with at least one incident cardiometabolic disease, with the strongest associations observed for incident IHD, HF, and AVB. Notably, incorporating dynamic shape PCs improved the prediction of incident IHD beyond standard CMR measures. GWAS identified 75 genetic loci associated with dynamic shape, including 14 variants previously unreported for cardiac traits, and candidate genes demonstrated enrichment in pathways related to cardiac development and contractile function. PRS derived from dynamic shape loci were significantly associated with multiple outcomes, most prominently HF. MR identified significant causal relationships between several PCs and cardiometabolic disease. ConclusionsDynamic cardiac shape features capture aspects of cardiac structure and function not fully represented by standard CMR measures. These features are strongly associated with incident cardiometabolic disease and provide new insights into the genetic architecture of cardiac remodeling. Clinical perspectiveO_ST_ABSWhat is new?C_ST_ABSO_LIGenetic and outcome relationships with a dynamic statistical shape model capturing both left and right ventricles at end-diastole and end-systole. C_LIO_LIDemonstration of incremental value over existing cardiac shape models, through capture of functional remodeling not represented by standard imaging measures. C_LIO_LIIdentification of genetic susceptibility loci for dynamic cardiac shape, including 14 variants not previously reported for cardiac traits. C_LI What are the clinical implications?O_LIThe results enhance our understanding of the genetic architecture of dynamic cardiac shape and function in the general population and clarify their relationships with other cardiovascular endophenotypes and incident cardiometabolic diseases. C_LIO_LINewly identified candidate genes expand the biological pathways implicated in cardiac remodeling and provide targets for future functional and mechanistic studies. C_LIO_LIThe improved prediction of incident cardiometabolic disease, particularly ischemic heart disease, achieved by adding dynamic shape PCs to traditional CMR measures suggests potential value for their inclusion in evaluation of patients. C_LI

Background. Hypertrophic cardiomyopathy (HCM) is a clinically variable disease in terms of onset and progression. Pathogenic MYBPC3 variants account for a substantial proportion of HCM diagnoses. This study sought to identify protein biomarkers associated with HCM severity. Methods. Olink-assayed plasma proteins of 144 MYBPC3 pathogenic variant carriers were tested for associations with HCM severity based on HCM diagnostic criteria (unaffected, mildly, or severely affected). The UK Biobank was used to replicate the identified proteins through considering time to onset of HCM (67 cases), cardiomyopathy (156 cases),and associations with cardiac MRI derived left ventricular maximum wall thickness (6,492 participants). Replicated proteins were further prioritised based on cardiac tissue expression and druggability, and annotated using pathway enrichment and association with onset of: heart failure (HF), dilated cardiomyopathy (DCM), sudden cardiac arrest (SCA), and ventricular arrhythmias (VA). Results. Among pathogenic MYBPC3 variant carriers, we identified 27 proteins associated with HCM severity. We independently replicated 21 proteins in the UK Biobank. Of the five prioritised proteins (NT-proBNP, GDF-15, FGF-23, ADM, and NCAM1), all but NT-proBNP were targeted by drugs with repurposing potential. The replicated proteins additionally associated with the incidence of HF (n=5), DCM (n=4), SCA (n=4), and VA (n=4). Conclusion. This study replicated 21 and prioritised five proteins associated with HCM severity in pathogenic MYBPC3 variant carriers. Replication in unselected HCM suggests the prioritised proteins are associated with HCM independent of genotype, providing important leads for plasma-based markers for diagnoses, disease monitoring, and drug targets.

ObjectivesTo identify unique echocardiographic signatures associated with TTR+ carrier status preceding onset of cardiac amyloidosis. BackgroundCarrier status for the most common pathogenic TTR variant in the United States, Val142Ile (V142I), found in 4% of African Americans (AA) and 1% of Hispanic/Latino (H/L) individuals, confers a 40-60% lifetime risk of developing variant transthyretin amyloidosis (ATTRv), including cardiac amyloidosis (CA) and heart failure (HF). Myocardial amyloid deposition is believed to progress over many years. Genomic screening programs and familial cascade genetic testing are increasingly uncovering pre-symptomatic TTR+ carriers, yet no guidelines exist to pragmatically risk stratify these individuals for CA. MethodsV142I+ carriers (cases) without prior diagnoses of amyloidosis or HF were identified among BioMe biobank participants with available exome sequencing data linked to electronic health records (EHRs) including at least one available echocardiogram. Controls were biobank participants with normal TTR sequencing who were age-, sex- and ancestry-matched to cases. Speckle-tracking echocardiography (STE) was applied to images and conventional and strain measurements were evaluated by univariate analyses. A random forest model was trained using a minimal redundancy maximal relevance (mRMR, applied to mitigate overfitting) feature set and evaluated by 5-fold cross-validation to minimize optimism bias. Discriminatory performance was assessed using the area under the receiver operating characteristic curve (AUC). Results49 TTR+ (100% V142I, median age 61 years, 69.4% female) and 45 matched TTR-biobank participants were included in the model development cohort. STE generated approximately 200 features. Univariate analyses revealed no significant differences between carriers and controls on any individual strain or conventional echocardiographic measurements including global longitudinal, right ventricular and left atrial strain. mRMR feature selection resulted in a set of 15 features retained for all downstream modeling, integrating global amyloid signatures, regional inferolateral strain abnormalities, layer-specific deformation, and mechanical timing heterogeneity. Using this feature set, the model achieved good discrimination (AUC=0.76). Feature importance analysis highlighted relative apical sparing, inferolateral strain reduction, and basal-apical timing gradients as key contributors to model performance. External validation (n=115) confirmed good model discrimination (AUC=0.781, 95% CI: 0.688-0.869, sensitivity 0.983). ConclusionsMachine learning applied to routinely acquired echocardiographic data can identify subtle myocardial abnormalities associated with TTR V142I carrier status prior to development of CA. Key model features are physiologically relevant to known echocardiographic characteristics of overt CA. Genotype-guided echocardiographic surveillance may be a scalable strategy for early detection of CA risk.

AimsCardiac myosin inhibitors (CMIs) have emerged as an alternative to septal reduction therapy (SRT) for obstructive hypertrophic cardiomyopathy (oHCM). However, comparative data on the time-trajectory of myocardial functional adaptation after septal myectomy (SM), alcohol septal ablation (ASA), and CMI are lacking. We compared temporal changes in echocardiographic parameters including LV global longitudinal strain (LVGLS) and LA reservoir strain (LASr) across these treatment strategies. Methods and ResultsIn this single-center retrospective cohort, symptomatic oHCM patients treated with SM (n=22), ASA (n=11), or CMI (n=47) underwent serial echocardiography with deep-learning-based automated strain analysis. Primary outcomes were temporal changes in LVGLS and LASr. Mixed-effects models adjusted for baseline clinical and echocardiographic variables were used to assess time-trajectories for up to 24 months. Treatment success rates were 86.4% (SM), 72.7% (ASA), and 93.6% (CMI). LVOT gradients were similarly reduced across groups. LVEF showed a subtle early decline after CMI (adjusted P-for-interaction=0.019). LVGLS gradually improved after SM and ASA but remained unchanged with CMI. LASr significantly improved after SM, showed minimal change after ASA, and demonstrated late attenuation beyond 9-12 months in the CMI group (adjusted P=0.029). ConclusionsDespite comparable LVOT gradient reduction, myocardial functional adaptation differed across therapies. Conventional SRT was associated with progressive improvement in LV and LA strain, whereas CMI therapy showed stable LVGLS with subtle early LVEF decline and late attenuation of LASr. These findings underscore the importance of longitudinal deformation imaging during CMI therapy and support reappraisal of SRT in selected patients requiring durable long-term management.

Whether the cumulative evidence for remote patient monitoring (RPM) in heart failure (HF) has reached a definitive threshold -- and whether benefits extend to geographically underserved populations -- remains uncertain. We conducted a systematic review, meta-analysis, and trial sequential analysis (TSA) of 65 RCTs (59 poolable; [~]23,000 participants) across four databases through February 2026, encompassing structured telephone support (15 trials), non-invasive telemonitoring (33), and invasive hemodynamic monitoring (11). Random-effects meta-analysis used REML with Hartung-Knapp-Sidik-Jonkman adjustment. RPM significantly reduced all-cause mortality (RR 0.890, 95% CI 0.819-0.966; P=0.007; I2=2.3%; k=41; NNT 84/year; prediction interval 0.820-0.965). TSA confirmed that accrued evidence exceeded the required information size, establishing firm evidence that additional RPM-versus-control trials are unlikely to overturn the mortality benefit. HF hospitalization was reduced (RR 0.782, 95% CI 0.711-0.859; P<0.001; k=39; NNT 17/year), though the prediction interval crossed 1.0 (0.589-1.038), indicating that in some settings the effect may be attenuated. No interaction by RPM type was observed (Pinteraction=0.15-0.24). GRADE certainty was moderate for mortality and low for HF hospitalization. A pre-specified geographic access analysis revealed that only 2 of 59 trials reported rural/urban subgroups -- a critical evidence gap that precludes conclusions about whether RPM differentially benefits underserved populations. HighlightsO_LITrial sequential analysis confirms firm evidence for RPM mortality benefit C_LIO_LIAll-cause mortality reduced 11% (NNT 84/yr, prediction interval excludes null) C_LIO_LIHF hospitalization reduced 22% (NNT 17/yr), though prediction interval crosses 1.0 C_LIO_LINo differential benefit by RPM type (STS vs TM vs invasive; Pinteraction=0.24-0.34) C_LIO_LIOnly 2 of 59 trials reported rural/urban subgroups -- a critical geographic evidence gap C_LI

BackgroundEvidence of the diverse genetic architecture of dilated cardiomyopathy (DCM) continues to emerge and requires reassessment of the clinical relevance of implicated disease genes. Building on the 2019-2020 Clinical Genome Resource (ClinGen) evaluation, the DCM Gene Curation Expert Panel (GCEP) reconvened in 2024-2025 to conduct a reassessment of genes in DCM. MethodsThe ClinGen semi-quantitative clinical validity classification framework was applied with specifications to DCM to classify genes into categories based upon strength of published evidence for a DCM phenotype. Previously curated genes were reassessed and newly reported gene-disease-mode of inheritance (MOI) relationships, termed "curations," were evaluated. ResultsSixty-eight genes were evaluated, inclusive of 72 unique gene-disease-MOI relationships across 51 previously evaluated and 17 newly assessed genes. Thirty-five curations were classified as high evidence (16 Definitive, 10 Strong, 9 Moderate), increasing by 16 from the prior assessment. Nine newly assessed genes were classified as high evidence, including BAG5, FLII, LMOD2, MYLK3, MYZAP, NRAP, PPA2, PPP1R13L, and RPL3L. Twelve genes (11 newly appraised) were rated as high evidence with an autosomal recessive (AR) MOI. Five re-evaluated genes from 2019-2020 had clinically significant changes in classification. Except for JPH2, for which curation was modified to separate autosomal dominant (-AD) and -AR MOI curations, clinically significant changes involved upgrades from low to high evidence categories (PLEKHM2, PRDM16, TBX20, TNNI3K), demonstrating the robustness of the ClinGen gene curation process over time. An additional 29 gene-disease-MOI curations were classified as Limited, including six newly evaluated genes and one new MOI for a previously evaluated gene, MYBPC3-AR; four were classified as No Known Disease Relationship, and four remained Disputed. Four previously evaluated genes were curated for both AD and AR MOIs, including JPH2 (AD-Strong, AR-Limited), LDB3 (AD-Limited, AR-Strong), MYBPC3 (AD-Limited, AR-Limited), and TNNI3 (AD- and AR- Strong). ConclusionsWith substantial new evidence, the genetic architecture of DCM has rapidly expanded. This updated assessment of genes reported in DCM yielded 35 high evidence curations, an increase from 19 only five years ago. The results of this evidence-based evaluation process informs clinical interpretation of genetic information in the care of DCM patients and families. CLINICAL PERSPECTIVEO_ST_ABSWhats new?C_ST_ABSO_LIThe Clinical Genome Resource (ClinGen) Dilated Cardiomyopathy (DCM) Gene Curation Expert Panel reconvened to update the evidence for genes in DCM using the ClinGen clinical validity framework. C_LIO_LIA total of 35 genes were classified into clinically actionable, high evidence categories of Definitive, Strong, or Moderate evidence, an increase of 16 from the 2019-2020 curation. C_LIO_LIOf the 16 newly classified high evidence curations, 11 (69%) had an autosomal recessive mode of inheritance and were observed primarily in pediatric DCM. C_LI What are the clinical implications?O_LIThis update has substantially expanded the complex and diverse genetic architecture of DCM spanning 18 gene ontologies (8 new) identified in both adult and pediatric patients. C_LIO_LIThe 19 genes classified as high evidence in the 2019-2020 curations were adopted by the clinical genetics community as the key genes for clinical genetic testing and care for DCM patients and families. The 35 high evidence curations from the current assessment are recommended to be used as an updated list for clinical genetics care for DCM. C_LIO_LIDCM gene curation will require ongoing reassessments due to the continuing expansion of high-quality research data. C_LI

Background Functional mitral regurgitation results from interacting mechanisms whose relative contributions vary between atrial and ventricular subtypes and shift dynamically within each heartbeat, producing temporal patterns that static analyses cannot capture. Objectives To identify which structural determinants predict mitral regurgitation variability beat to beat using Granger causality within vector autoregression, focusing on papillary muscle dynamics across subtypes. Methods Frame-level echocardiographic time series from 41 patients (21 atrial, 20 ventricular; 1,959 frames) were z-score standardised within patient. Individual (lag 3) and pooled (lag 2) vector autoregression models tested whether left ventricular volume, left atrial volume, papillary muscle length, and annulus diameter Granger-predict mitral regurgitation area. Results Individual models revealed marked heterogeneity. In pooled analysis, left ventricular volume was the strongest Granger predictor at short lags (atrial p=0.011; ventricular p=0.006), while left atrial volume emerged at longer lags (lag 7: atrial p=0.043; ventricular p=0.011). Systolic papillary muscle length was not predictive. Full-cycle analysis revealed a subtype-specific dissociation: papillary muscle length Granger-predicted regurgitation only in the ventricular subtype (p=0.001), while regurgitation predicted papillary muscle displacement only in the atrial subtype (p<0.001). Left ventricular volume dominated within-beat prediction but lost cross-beat relevance in the ventricular subtype, while left atrial volume gained cross-beat predictive relevance in the atrial subtype. No structural determinant correlated with severity cross-sectionally. Conclusions Beat-to-beat vector autoregression and Granger modelling reveals heterogeneous, subtype-specific temporal patterns with distinct temporal windows of predictability for ventricular loading and papillary geometry. This framework may support patient-specific temporal phenotyping of functional mitral regurgitation.

Background: The clinical significance of sarcomere variants of uncertain significance (VUS) in hypertrophic cardiomyopathy (HCM) remains unclear, and VUS are currently regarded as clinically non-actionable despite their increasing prevalence. This study aimed to evaluate genotype?phenotype and genotype?outcome associations according to variant pathogenicity in patients with HCM, with a particular focus on the clinical relevance of sarcomere VUS. Methods: This multicenter retrospective cohort study included 438 patients with HCM who underwent next-generation sequencing-based genetic testing at two tertiary hospitals. Patients were classified into three groups: pathogenic or likely pathogenic (P/LP) variants, VUS, and no sarcomere mutations. Clinical characteristics, imaging phenotypes, and outcomes were compared across groups. The primary endpoint was a composite of cardiovascular death, aborted sudden cardiac death, appropriate implantable cardioverter-defibrillator therapy, and heart transplantation. Time-to-event analyses were performed using Kaplan-Meier methods and Cox proportional hazards models with Firth's penalized partial likelihood approach. Results: P/LP variants were identified in 171 patients (39.0%) and sarcomere VUS in 159 patients (36.3%). Patients with VUS demonstrated intermediate clinical and phenotypic features between P/LP carriers and genotype-negative patients. Kaplan?Meier analysis showed a graded difference in event-free survival across variant classifications. While VUS were not independently associated with adverse outcomes when modeled as a categorical variable, increasing pathogenicity from genotype-negative to VUS and P/LP variants was associated with a stepwise increase in risk of the primary endpoint (hazard ratio 2.05, 95% confidence interval 1.11?4.16 p=0.019). Identified VUS were preferentially enriched in Z-disc and giant sarcomere scaffolding proteins. Conclusion: Sarcomere VUS represent intermediate characteristics along a continuum of sarcomere dysfunction, associated with distinct phenotypic features and clinical outcomes compared with both P/LP variants and the absence of sarcomere mutations. These findings suggest that sarcomere VUS may not be entirely clinically neutral and should be interpreted within a broader genetic and structural context in patients with HCM.

Abstract Background: Hypertrophic (HCM) and dilated (DCM) cardiomyopathy constitute the principal phenotypes of primary cardiomyopathy, yet both lack sufficient therapeutic options. Integrating genetic insights with detailed cardiac phenotyping offers a promising strategy to prioritize targets and elucidate their mechanisms of action. Methods: We conducted an three-stage analysis. First, drug-target Mendelian randomization (MR) was performed using cis-acting protein (pQTL) and expression (eQTL) quantitative trait loci as genetic instruments for potential drug targets. Second, we examined causal associations between 82 cardiac magnetic resonance (CMR)-derived imaging traits and HCM/DCM risk in a CMR-based MR analysis. Third, mediation MR was employed to quantify the proportion of the genetic effect of prioritized drug targets on cardiomyopathy risk that was mediated through specific CMR phenotypes. Results: Our analyses identified 19 and 13 potential therapeutic targets for HCM and DCM, respectively. CMR-based MR revealed that HCM risk was causally associated with increased right ventricular ejection fraction (RVEF) and greater left ventricular wall thickness, whereas DCM risk was linked to ventricular dilation, impaired myocardial strain, and altered aortic dimensions. Critically, mediation analysis established that these CMR traits served as significant intermediate pathways. The protective effect of ALPK3 on HCM risk was mediated through a reduction in myocardial wall thickness. Conversely, the effects of PDLIM5, HSPA4, and FBXO32 on DCM risk were exerted in part via alterations in aortic dimensions. Conclusion: This integrative genetic and imaging study systematically identify candidate therapeutic targets for HCM and DCM and delineates the specific CMR phenotypes through which they likely exert their causal effects. Our findings advance the understanding of disease pathogenesis and highlight new possibilities for improving the diagnosis and management of cardiomyopathy.

Background: Progression of transthyretin (TTR) amyloid cardiomyopathy (ATTR-CM) can lead to worsening congestion requiring diuretic intensification (DI), heart failure (HF)-related hospitalizations (HFH), and death. Tafamidis was the only approved ATTR-CM therapy in the US from 2019 until the 2024 approval of acoramidis, which achieves near-complete ([&ge;]90%) TTR stabilization. As head-to-head trials are lacking, real-world comparative effectiveness (CE) data are needed to guide treatment selection. Objective: To evaluate real-world CE of acoramidis versus tafamidis in newly treated patients with ATTR-CM. Methods: Retrospective study using Komodo Healthcare Map (R) US claims data tokenized to Claritas. Patients newly initiating acoramidis or tafamidis between 12/11/2024 and 04/30/2025 with [&ge;]1 prescription claim (first defined as index date) and [&ge;]6 months of continuous enrollment preindex date were included and followed until disenrollment, death, treatment switch, or study end date (07/31/2025). Outcomes included DI (initiation or dose-equivalent escalation of oral loop diuretics, parenteral loop diuretic use, or addition of thiazide-like diuretic) and a composite of DI, HFH (inpatient admission with a HF-related ICD-10-CM diagnosis code in any position), and mortality. Propensity score weighting balanced baseline characteristics, disease severity, comorbidity burden, and baseline medication use. Time-to-event outcomes were assessed using weighted Cox proportional hazards models. Results: After weighting, acoramidis (n=170) and tafamidis (weighted sample size=448) patients were comparable at baseline (mean age, 78.6 vs 78.7 years; male, 80.0% vs 80.2%) with mean follow-up of 139 and 143 days, respectively. DI cumulative incidence curves separated early and remained divergent, with acoramidis significantly reducing the hazard of DI events by 43% compared with tafamidis (11.8% vs 20.5%; HR, 0.57; 95% CI, 0.35-0.92; P=0.021). Acoramidis also had a significantly lower risk of composite events, with a 34% reduction in hazard compared with tafamidis (17.6% vs 26.4%; HR, 0.66; 95% CI, 0.44-0.99; P=0.046). Conclusions: In this first real-world CE study of newly treated patients, acoramidis had significantly lower risk of DI events and composite events of DI, HFH, and mortality than tafamidis, potentially supporting improved clinical stability with acoramidis initiation. Additional evaluation with longer follow-up, larger cohorts, and/or prospective clinical outcomes is warranted.

BackgroundSodium-glucose co-transporter 2 (SGLT2) inhibitors have emerged as a cornerstone of heart failure (HF) therapy, yet the totality of randomized evidence -- including smaller trials -- has not been comprehensively synthesized. We aimed to evaluate the efficacy and safety of SGLT2 inhibitors across the full spectrum of HF. MethodsWe searched PubMed, Cochrane CENTRAL, ClinicalTrials.gov, and WHO ICTRP from inception to March 2026 for randomized controlled trials comparing any SGLT2 inhibitor with placebo or standard care in adults with HF. Primary outcomes were all-cause mortality (ACM) and HF hospitalization (HFH). We used random-effects models with Mantel-Haenszel risk ratios and Hartung-Knapp-Sidik-Jonkman confidence intervals. Certainty of evidence was assessed using GRADE. The protocol was registered prospectively (PROSPERO CRD420251167908). ResultsOf 6,239 records identified, 114 studies met inclusion criteria and 59 RCTs (29,692 participants) were included in quantitative synthesis. SGLT2 inhibitors significantly reduced ACM (RR 0.90 [0.83, 0.98], p = 0.016; 26 trials; I2 = 0%; low certainty) and HFH (RR 0.74 [0.69, 0.79], p < 0.001; 15 trials; I2 = 0%; moderate certainty). The composite of CVD and HFH was reduced (RR 0.80 [0.75, 0.85], p < 0.001; high certainty). Genital infections were significantly increased (RR 3.75 [1.72, 8.19], p = 0.007). Results were robust across 12 sensitivity analyses and 4 alternative statistical models. ConclusionsSGLT2 inhibitors reduce all-cause mortality, HF hospitalization, cardiovascular death, and serious adverse events in adults with HF, with an acceptable safety profile apart from increased genital infections. These findings support the use of SGLT2 inhibitors as a foundational therapy across the HF spectrum.

Background and Aims: Acute myocarditis (AM) is a T cell-mediated myocardial disease with clinical manifestations ranging from mild chest pain to cardiogenic shock. Reliable biomarkers to stratify patients and guide therapy are currently lacking. In particular, the extent of the dysregulation of inflammatory pathways, and the impact on myocardial dysfunction, remain elusive. Methods: Serum analyses were performed in prospectively recruited AM patients (n = 103) from two independent cohorts. Multimodal data integration combining profiling of cytokine and chemokine dysregulation with clinical biomarkers was used to define clinical phenotypes with distinct inflammatory signatures. Machine-learning and regression models were applied to determine biomarkers that indicate clinical severity. Results: Immuno-proteomic profiling revealed conserved inflammatory patterns across AM cohorts, dominated by T cell-related cytokines and chemokines. In addition, AM patients showed dysregulation of fibroblast-derived cytokines, including hepatocyte growth factor (HGF), bone morphogenic protein 4 (BMP4) and the BMP4 inhibitors Gremlin-1 (GREM1) and Gremlin-2 (GREM2). Data integration and unsupervised clustering revealed two immuno-clinical phenotypes, linking T cell activation and fibroblast dysregulation to disease severity. Machine learning-based analysis identified CXCL10, GREM2 and LVEF as critical parameters for stratifying disease severity. Conclusions: These findings highlight a systemic T cell activation signature as diagnostic hallmark of AM. In addition, dysregulation of fibroblast-derived tissue cytokines serves as an indicator for distinct immuno-clinical phenotypes in myocardial inflammatory disease. Thus, the clinically relevant link between T cell-driven immune activation, myocardial inflammation and fibroblast-driven remodelling provides a versatile set of parameters to identify severe manifestations of AM.

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

Introduction: Spontaneous coronary artery dissection (SCAD) is frequently accompanied by persistent symptoms of unknown pathogenesis after the index event. Autonomic dysfunction is a plausible mechanism for these but has not been systematically characterized. We quantified antecedent and contemporary autonomic symptoms in survivors of SCAD and examined their associations with cardiac and extra-cardiac symptoms and health-related quality of life. Methods: This cross-sectional study recruited 227 volunteers from multiple countries with a self-reported history of SCAD. Participants completed validated patient-reported measures, including the Composite Autonomic Symptom Score-31 (COMPASS-31), Anxiety Sensitivity Index-3 (ASI-3), and EuroQol-5 Dimension-5L (EQ-5D-5L). They also completed an internally derived retrospective autonomic predisposition score assessing symptoms during adolescence and early adulthood. Results: Participants were predominantly female (97.8%), median age 53 (47-58) years, and were surveyed a median of 3 (1-5) years after their index SCAD event. 21.6% reported SCAD recurrence. Moderate autonomic symptom burden (COMPASS-31 20) was present in 56.4% and severe burden (40) in 16.3%. History of antecedent autonomic symptoms was the strongest independent predictor of contemporary autonomic symptom burden after adjustment for demographic and clinical covariates (=0.514; P <0.001). Greater autonomic symptom burden independently predicted lower EQ-5D health utility (=0.150; P=0.029) and was associated with the ASI-3 physical concerns (=0.232; P <0.001), but not social concerns domain. Autonomic symptoms were not associated with SCAD recurrence. Conclusion: Symptoms of autonomic dysregulation are common in survivors of SCAD and are associated with reduced quality of life. Their association with antecedent dysautonomic features during adolescence and early adulthood suggests a longstanding predisposition, the significance of which warrants further evaluation.

BackgroundThis study of Malawian children with rheumatic heart disease (RHD) sought to detect demographic, clinical, and echocardiographic risk factors for mortality. MethodsPediatric patients with RHD were recruited from March to October, 2018 from clinic rosters and inpatient consults in Lilongwe and Blantyre, Malawi. An echocardiogram was performed upon study enrollment. Cox regression analyses were performed to assess for factors associated with mortality over nearly 2 years of follow-up. ResultsOf 118 patients, nearly two-thirds were female (64.4%) and median age was 12 (IQR 10-14). Just under half (47.0%) lived >40km from a tertiary care center. There was a high prevalence of severe mitral regurgitation (65.3%), and pericardial effusion was present in 18.6%. Nearly a quarter (23.7%) died during follow-up. In univariable Cox regression, living >40km from tertiary care, living in a remote area, moderate or severe malnutrition, taking a beta blocker, severe mitral stenosis, any severe valve disease, severe left atrial enlargement, and presence of a pericardial effusion were statistically significant risk factors for mortality (p<0.05). In the adjusted model, living >40km from tertiary care (HR 2.66, CI 1.06-6.07, p=0.037), malnutrition (mild HR 3.92, CI 1.03-14.91, p=0.045); moderate HR 7.41, CI 1.92-28.54, p=0.004; severe HR 4.91, CI 1.44-16.71, p=0.011), beta blocker use (HR 4.62, CI 1.63-13.10, p=0.004), and presence of a pericardial effusion (HR 6.96, CI 3.00-16.13, p<0.001) remained independent risk factors for mortality. ConclusionsThis study of Malawian children emphasizes the dire prognosis of RHD in under-resourced settings and provides potential area of focus for targeted intervention.

Background: Heart failure (HF) is a major and growing public health problem, and prior studies support a meaningful genetic contribution to HF susceptibility. Clinically, HF is commonly categorized into the major clinical sub-types of HF with reduced ejection fraction (HFrEF) and HF with preserved ejection fraction (HFpEF), which differ in pathophysiology and clinical profiles. However, previous genome-wide association studies have focused on autosomal variation and have routinely excluded the X chromosome, leaving X-linked genetic contributions to HF and its subtypes under-characterized. Methods: We performed X-chromosome wide association study (XWAS) utilizing directly genotyped data from 590,568 Million Veteran Program participants, including 90,694 HF cases across European, African, Hispanic, and Asian Americans. Sex- and ancestry-stratified logistic regression was used with XWAS quality control measures, adjusting for age and population structure, followed by fixed-effects multi-ancestry meta-analysis. Functional annotation, gene-based testing, fine-mapping, and colocalization were performed. We replicated genetic associations with all-cause HF in the UK Biobank. Results: In the multi-ancestry meta-analysis, we identified five X-chromosome-wide significant loci for all-cause HF, five for HFrEF, and one locus for HFpEF in males. No loci reached significance in female-specific analyses. In sex-combined analyses, we identified six loci for all-cause HF and four for HFrEF. The strongest and most emphasized signals mapped to genes were BRWD3, FHL1, and CHRDL1. Ancestry-specific analyses revealed additional loci, including NDP and WDR44 in African ancestry and PHF8 in Hispanic ancestry. One locus, BRWD3, was replicated in UK Biobank HF cohort. Integrated post-GWAS analyses (fine-mapping, colocalization and pleiotropy trait association studies) reinforced the biological plausibility of the X-linked signals. Conclusions: This multi-ancestry, sex-stratified XWAS identifies X-linked genetic contributions to HF and its subtypes and highlights the role of X-chromosome in heart failure pathogenesis.