European Heart Journal

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.

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.

Aims: Assessment of treatment response in HFrEF has largely relied on left ventricular (LV)-centric parameters, yet the left atrium (LA) plays a central role in modulating LV filling and reflects the cumulative hemodynamic burden. Whether discordant recovery between LV and LA function carries distinct prognostic implications in patients treated with ARNI-based therapy remains unknown. Methods and results: From the multicenter STRATS-HF-ARNI registry, 1,182 patients with HFrEF who underwent serial echocardiography at baseline and one-year follow-up were included. Patients were classified into four strain recovery phenotypes according to the direction of change in LVGLS and LASr at one year: Group A, concordant recovery (57.4%); Group B, discordant atrial non-recovery (11.2%); Group C, discordant ventricular non-recovery (15.6%); and Group D, concordant non-recovery (16.0%). Clinical outcomes included all-cause mortality, cardiovascular mortality, and HF hospitalization. Despite achieving LV functional improvement, Group B exhibited persistent LASr deterioration, accompanied by less favorable hemodynamic trajectories compared with Group A. On multivariable Cox regression, Group B was associated with significantly higher risks of all-cause mortality (adjusted hazard ratio [aHR] 3.53, 95% confidence interval [CI] 1.60-7.79) and cardiovascular mortality (aHR 5.68, 95% CI 1.91-16.92), comparable to Group D. Group C demonstrated higher HF hospitalization risk (aHR 2.25, 95% CI 1.31-3.86). The adverse prognostic impact of discordant atrial non-recovery was consistently observed across subgroups stratified by baseline LVGLS and LASr levels. Conclusion: In HFrEF patients treated with ARNI-based therapy, persistent LA dysfunction despite LV functional improvement identifies a high-risk phenotype comparable to concordant non-recovery. These findings suggest that concurrent assessment of LV and LA strain may provide incremental prognostic value beyond LV-centric metrics alone.

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.

Rationale: Heart failure with preserved ejection fraction (HFpEF) is a heterogeneous syndrome with substantial unmet diagnostic and therapeutic needs. Circulating lipid metabolism is increasingly implicated in HFpEF pathophysiology but has not been systematically leveraged for molecular stratification. Objective: To determine whether plasma lipidomics can identify molecular phenogroups of HFpEF associated with distinct clinical characteristics and outcomes. Methods and Results: Untargeted plasma lipidomics was performed in non-HF subjects and HFpEF patients from a primary Belgian cohort and an independent Canadian cohort (n=177 in each cohort). In the Belgian cohort, 235 unique lipids spanning 19 subclasses were annotated, including 96 significantly associated with HFpEF (q<0.02). Unsupervised analyses revealed marked lipidomic heterogeneity, with a distinct HFpEF subgroup separable from non-HF subjects. Hierarchical clustering identified three phenogroups with divergent lipid profiles and clinical features. One phenogroup exhibited severe atrial dysfunction, congestion-related biomarkers, elevated indices of cardiac and liver fibrosis, and markedly reduced survival, a second was characterized by prominent metabolic syndrome features, and a third by preserved renal function. Cross-cohort comparison using a supervised classifier trained on 158 shared lipids confirmed analogous lower-risk phenogroups in the Canadian cohort, while the high-risk phenotype was underrepresented. A signature of 10 lipids across six subclasses, including long-chain acylcarnitines, ether phosphatidylcholines, and oxidized sphingomyelins, discriminated the high-risk group and correlated with markers of disease severity. Conclusion: Our findings demonstrate that HFpEF comprises metabolically distinct patient subgroups across cohorts, revealing specific lipidomic dysfunctions that deepen our understanding of HFpEF heterogeneity and underlying pathophysiology.

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.

RationaleRV adaptation in pulmonary hypertension is sexually dimorphic and more preserved in women. NLRP3 inflammasome activation contributes to RV failure (RVF) development. However, regulators and downstream effects of NLRP3 activation in the RV remain unknown. ObjectivesWe investigated whether NLRP3 inflammasome activation in RVF is sexually dimorphic, whether NLRP3 is active in RV cardiomyocytes (RVCMs) and causes RVCM contractile dysfunction, and whether 17{beta}-estradiol (E2) and its receptor ER attenuate this process. MethodsWe studied RV tissues from PAH patients with RVF, RV tissues and RVCMs isolated from wild-type and ER loss-of-function mutant rats with RVF, isolated perfused rat hearts, and human induced pluripotent stem cell (hiPSC)-derived cardiomyocytes. NLRP3 activation was assessed via RNA-sequencing, proteomics, immunostaining, and downstream target quantification. RV contractility was assessed via pressure-volume loops, perfused heart studies, and contractility and calcium assessments in isolated RVCMs. Measurements and Main ResultsNLRP3 was upregulated in RVCMs during RVF and resulted in altered RVCM calcium handling and RVCM contractile dysfunction. In human RVs, hiPSC-cardiomyocytes and rat RVs, NLRP3 activation and NLRP3-induced RVCM contractile dysfunction were sexually dimorphic and male-biased. Ovariectomy and loss of ER in females eliminated this sex bias. E2, via ER, prevented RVCM NLRP3 activation and NLRP3-induced RVCM contractile dysfunction in males and ovariectomized females during both acute and chronic RV pressure overload. ER directly interacted with NLRP3. ConclusionsNLRP3-driven RVCM contractile dysfunction is male-biased. E2 inhibits NLRP3 through ER to preserve RVCM contractility. Targeting E2-ER-NLRP3 signaling may offer novel therapeutic strategies for RVF in low estrogen states. ImpactThis is the first study to define a novel estradiol-estrogen receptor -NLRP3 axis that modulates RV cardiomyocyte function and RV adaptation in pulmonary hypertension. We demonstrate for the first time that NLRP3 activation is therapeutically targetable in low estrogen states via NLRP3 inhibitors or 17{beta}-estradiol. These findings have direct implications for therapeutic strategies aimed at preserving or restoring RV contractile function in pulmonary hypertension, a current area of unmet clinical need.

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.

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.

Aims: Although metabolic dysregulation is implicated in DCM, the involvement of metabolic syndrome (MetS) remains unclear. This study aims to systematically examine MetS in DCM pathogenesis. Materials and methods: By leveraging 378,837 UK Biobank participants, instead of the conventional binary MetS, we calculated a continuous metabolic risk score (MRS) and evaluated its influence on DCM risk within a multi-model evidence framework. Bidirectional weighted quantile sum regression identified key MRS components, a nested case-control study assessed 14-year pre-diagnosis MRS trajectories, mediation analyses evaluated MRS mediating lifestyle-DCM links and inflammation mediating MRS-DCM relationships, and Mendelian randomization (MR) evaluated causality for genetically predicted MetS and components on DCM. Results: During a median follow-up period of 13.4 years (interquartile range 12.7~14.1 years), 820 (0.2%) participants developed DCM. Higher MRS (HR=1.26 [1.18~1.34]) was associated with increased DCM risk, and such an association persisted across all robustness assessments even among non-MetS individuals. Waist circumference (WC, HR=1.36 [1.28~1.45], weight=0.58) and glycated hemoglobin (HR=1.23 [1.16~1.30], weight=0.22) dominated MRS' risk contribution. The trajectories of MRS diverged in cases approximately 10 years pre-diagnosis. MRS mediated 5.1~26.2% of lifestyle-related DCM risk, while inflammation mediated 16.4% of the MRS-DCM association. MR analysis further confirmed causal effects of MetS (OR=1.65 [1.45~1.88]), WC (OR=1.79 [1.58~2.03]) on DCM risk. Conclusions: Metabolic dysfunction, which was dominated by central adiposity and hyperglycemia, plays a key role in the occurrence of DCM. Early intervention targeting metabolic factors may prevent DCM onset.

Background: Among cardiac measures, diastolic parameters demonstrate the earliest and most consistent age-related changes. This can be leveraged to develop a continuous left ventricular (LV) Diastolic Age from routine echocardiographic parameters. Analogous to how epigenetic clocks weight molecular markers against mortality risk, we calibrated Diastolic Age by weighting echocardiographic features against the validated PREVENT-Heart Failure (HF) risk score. Methods: We analyzed 1,952 participants from the Project Baseline Health Study (median age 50 [36-64] years, 54% female). The measure was derived using partial least-squares regression anchored on PREVENT-HF and calibrated within a healthy reference subgroup. External validation was performed in the WASE (n=1,708) and Stanford Cardiovascular Aging (n=313) cohorts. Associations with ASE-defined LV diastolic dysfunction (LVDD), epigenetic clocks, and major adverse cardiovascular events (MACE) were examined. Results: Diastolic Age correlated strongly with chronological age (r=0.78) with robust external validation (WASE r=0.76; Stanford r=0.82; calibration slopes {approx}1.0). It increased progressively across grades of diastolic dysfunction and discriminated LVDD with an AUC of 0.89 (95% CI 0.87-0.92), and was independently associated with hypertension, diabetes, and elevated C-reactive protein. While correlated with the Levine (r=0.76) and Horvath (r=0.41) epigenetic clocks, residual analyses indicated that Diastolic Age captures a distinct cardiac-specific dimension of biological aging. Over median follow-up of 4.2 years, it independently predicted MACE (HR 2.30, 95% CI 1.70-3.18), with accelerated diastolic aging across all age groups among those with events. Discrimination was comparable to ASE-defined LVDD (C-index 0.83 vs. 0.82). Conclusion: Diastolic Age provides a continuous, echocardiography-derived measure of cardiac biological aging that complements categorical diastolic grading and epigenetic aging clocks, and independently predicts cardiovascular outcomes.

BackgroundHeart failure (HF) is an increasingly common complication among patients with type 2 diabetes (T2D), yet its early detection remains challenging, especially in those with concomitant chronic kidney disease (CKD). NT-proBNP is a key biomarker for diagnosing and prognosticating HF, but its reference thresholds are influenced by renal function, age, and ethnicity. Current guideline cutoffs, largely derived from Western populations, may not apply to Asian patients. MethodsThis retrospective cohort study included 10,587 adults with T2D who underwent NT-proBNP testing between 2006 and 2021 at the National Taiwan University Hospital. Patients with prior HF were excluded. Generalized additive models identified NT-proBNP thresholds associated with HF hospitalization, and Kaplan-Meier analysis validated outcome separation. Subgroup analyses were stratified by age, sex, body mass index (BMI), and estimated glomerular filtration rate (eGFR). ResultsDuring a mean follow-up of 3.5 years, 1,892 (17.9%) patients were hospitalized for HF. NT-proBNP levels of 179 pg/mL (outpatient) and 728 pg/mL (emergency) marked inflection points for rising event risk (log-rank p < 0.0001). Age-specific analyses showed progressive increases in optimal thresholds: from 85 (<50 years old), 150 (50-74 years old) and 290 pg/mL ([&ge;]75 years old) in outpatients, and from 310, 600 and 1,165 pg/mL, respectively, in emergency settings. In the BMI-stratified analysis, NT-proBNP thresholds demonstrated an inverse relation with BMI. Considering renal function, the optimal cutoffs were 100, 310, and 935 pg/mL for eGFR > 60, 30-60, and < 30 mL/min/1.73 m{superscript 2}, respectively; in the emergency cohort, the corresponding thresholds were 290, 835, and 3,905 pg/mL. ConclusionsThis large Asian cohort defines setting- and renal function-specific NT-proBNP thresholds for predicting HF hospitalization in patients with T2D. The lower optimal cutoffs compared with Western guidelines highlight the need for ethnicity-adjusted diagnostic criteria to improve early identification and risk stratification of HF in clinical practice. What is new?O_LIIn a large real-world Asian cohort of patients with type 2 diabetes, we identified setting-specific NT-proBNP thresholds (179 pg/mL outpatient; 728 pg/mL emergency) associated with heart failure hospitalization risk. C_LIO_LIAge-, BMI-, and kidney function-stratified cutoffs revealed substantial heterogeneity in optimal NT-proBNP thresholds. C_LIO_LICompared with guideline-recommended values, Asian-specific thresholds were consistently lower ([~]30-40%), supporting ethnic differences in natriuretic peptide biology. C_LIO_LIA generalized additive model (GAM) captured nonlinear biomarker-risk relationships, enabling data-driven and clinically interpretable cutoff identification. C_LI What are the clinical implications?O_LIUse of ethnicity- and context-specific NT-proBNP thresholds may improve early detection of heart failure in Asian patients with type 2 diabetes. C_LIO_LIIncorporating kidney function and BMI into NT-proBNP interpretation enhances risk stratification, particularly in patients with CKD. C_LIO_LIReliance on Western guideline cutoffs may underestimate heart failure risk in Asian populations. C_LIO_LIThese findings support a precision medicine approach to biomarker interpretation and highlight the need for population-specific guideline refinement. C_LI

BackgroundPatients with repaired coarctation of the aorta (CoAo) remain at risk for left ventricular hypertrophy (LVH) even in the absence of hypertension. Alterations in wave reflection and the timing of reflected pressure waves may contribute to ventricular remodeling beyond pressure load alone. MethodsWe performed a cross-sectional analysis of patients with repaired CoAo. Office and ambulatory blood pressure (ABPM), non-invasive central hemodynamics, and echocardiographic indices of left ventricular structure were assessed. Linear and multivariable regression models evaluated associations with posterior wall thickness (PWTd) and interventricular septal thickness (IVSTd). Computational simulations were conducted to examine the impact of heart rate on ventricular remodeling. ResultsFifty-seven patients (median post-repair follow-up 11 years) were included. LVH prevalence was 15.2% (95% CI: 4.8-25.6). Although 42% met criteria for hypertension based on ABPM, no patients exhibited elevated central blood pressure. Adjusted augmentation index (AIX@75) was inversely associated with PWTd and remained independently associated after multivariable adjustment (R2 = 0.40, p < 0.01). Replacing AIX@75 by heart rate improved model performance (R2 = 0.44), with lower heart rate independently associated with greater PWTd. Simulation modeling showed that a 10% increase in heart rate reduced mean PWTd and decreased posterior wall hypertrophy prevalence from 30.9% to 2.4% (OR =0.10; 95% CI: 0.01-0.44). ConclusionsVentricular remodeling occurs despite normal central blood pressure in CoAo. A lower heart rate associates with increased ventricular mass. Heart rate-mediated modulation of wave reflection timing represents a potential mechanistic and therapeutic target.

Aims: Dynamic left ventricular outflow tract obstruction (LVOTO) is a hemodynamically significant complication following transcatheter aortic valve replacement (TAVR) that remains difficult to predict with conventional transthoracic echocardiography (TTE). We examined whether a deep learning (DL) model developed for LVOTO detection in hypertrophic cardiomyopathy (HCM) could predict post-TAVR LVOTO from pre-TAVR TTE in patients with severe aortic stenosis (AS). Methods and Results: In this retrospective study of 302 consecutive patients undergoing TAVR for severe AS, a pre-trained DL model was applied to pre-TAVR TTE to generate a patient-level DL index of LVOTO (DLi-LVOTO; range 0-100). Post-TAVR LVOTO was defined as a peak pressure gradient [&ge;]30 mmHg on follow-up TTE. Logistic regression and receiver operating characteristic analyses assessed the association and discriminative performance of DLi-LVOTO. Pre-TAVR LVOTO was present in 32 patients (10.6%) and post-TAVR LVOTO in 35 (11.6%). Follow-up TTE was performed at a median of 47 days (IQR 37-63) after TAVR, with the majority of TTE (216 of 302, 71.5%) performed within 2 months. DLi-LVOTO was significantly higher in patients with LVOTO at both pre- and post-TAVR TTE (all p<0.001). In multivariable analysis, DLi-LVOTO remained independently associated with post-TAVR LVOTO even after adjusting for conventional TTE parameters and pre-TAVR LVOTO (adjusted OR 1.29, 95% CI 1.06-1.56 per 10-score increase, p=0.011), with an AUROC of 0.78 (95% CI 0.72-0.85). Among patients without pre-TAVR LVOTO, DLi-LVOTO retained independent predictive value (adjusted OR 1.56, 95% CI 1.19-2.06, p=0.001; AUROC 0.84, 95% CI 0.77-0.91). Conclusion: A DL model originally trained in HCM patients independently predicts post-TAVR LVOTO from pre-TAVR TTE, including in patients without pre-existing LVOTO, suggesting it captures hemodynamic features beyond conventional echocardiographic assessment.

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.

BACKGROUND: Guidelines recommend aortic valve replacement (AVR) in patients with severe aortic regurgitation (AR) based on progressive changes in left ventricular (LV) function or size. We aimed to reassess the clinical relevance of current guideline recommendations pertaining to traditional echocardiographic measurements in routine practice. METHODS: Retrospective analysis of patients with severe AR who underwent serial echocardiographic follow-up over at least 18 months. The composite outcome was symptom-driven AVR, acute heart failure hospitalization, or death. We used a joint modelling approach to handle within-subject correlation and censoring. RESULTS: The cohort consisted of 140 patients, with a median follow?up of 93 months (interquartile range 58?130). LV end-systolic (LVESD) and fractional shortening (FS) showed a small but statistically significant longitudinal trend, while LVEDD did not. Changes in all three parameters in parallel joint models adjusted for age and gender were consistently associated with increased risk of the composite event. Each 1?mm increase in LVESD and LVEDD was associated with a 6% and 5% increase in risk, respectively; each 1% decrease in FS corresponded to a 12% increase in risk. Only 8 (5.7%) of patients were predicted to exceed the guideline-recommended LVEDD threshold of 65 mm over 10 years. Age at onset was also a significant risk factor, with each decade increasing risk by 65% for each of the three parallel joint models. CONCLUSIONS: LV parameters show modest changes over time, despite holding strong prognostic value in patients with severe AR. LVEDD, while associated with overall risk, does not predictably or significantly dilate over time in most patients. AVR decisions should be based on comprehensive clinical and volumetric assessment rather than waiting for simple linear progression to guideline cutoffs.

BackgroundLeft atrial (LA) remodeling, a hallmark of chronically elevated LA pressure, is characterized by enlargement and functional impairment. While global and reservoir LA functions are well described, the role of LA booster function and its failure remains poorly defined. ObjectivesTo characterize LA booster function using cardiac computed tomography angiography (CCTA) and to evaluate the relationship between LA preload, booster performance, remodeling, and clinical outcomes. MethodsWe retrospectively analyzed 975 patients who underwent spiral CCTA between 2010 and 2018. Phasic LA and LV volumes were obtained, from which LA reservoir and booster functions were derived. LA performance curve was constructed by plotting LA pre-A volume (preload) against LA booster stroke volume. Clinical outcomes (heart failure, stroke, or cardiovascular death) were analyzed based on the LA performance curve. ResultsLA pre-A volume strongly correlated with LA end-systolic volume (r=0.92, p<0.001). The LA booster stroke volume displayed an inverted U-shaped relation to LA pre-A volume (linear coefficient 0.64, P<0.0001; squared coefficient-0.0029, P<0.0001). The atrial booster function curve reached its vertex at 107 mL (95% CI 90 to 113 mL), indicating that the booster pump response for the increased preload is exhausted at this point. Booster dysfunction was associated with impaired reservoir function (r=0.77, p<0.001) and reduced LA systolic flow rates (-0.79, P<0.001). Patients with increased LA pre-A volume but reduced booster volume ("LA failure") exhibited the highest event rate of the combined endpoint of heart failure, stroke or cardiovascular mortality (43.2%, 95% CI 33.6-54.2%). ConclusionsLA enlargement predominantly serves to increase LA pre-A volume to sustain booster function. LA contractile dysfunction affects global LA function via a concomitant reduction in LA reservoir volume. LA failure can be defined as reduced booster contraction despite elevated preload, portending poor clinical outcomes.

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.

BackgroundVarious measurements around the aortic valve are typically made on computed tomography angiograms (CTAs) before transcathether aortic valve replacement (TAVR) for aortic stenosis (AS), but their collective prognostic inference on periprocedural conduction disturbances (CDs) is not known. Here, we aimed to use unsupervised machine learning (UML) to analyze a multitude of pre-TAVR CTA features and uncover patient subphenotypes with differential risks of CDs. MethodsTwelve nonredundant features involving the aortic valve, aortic root, and ascending aorta were extracted from the CTAs of 660 AS patients. UML of these features using agglomerative hierarchical clustering was performed on separate male and female datasets, with the optimal number of clusters determined by 30 cluster indices. Multivariable logistic regression was conducted to assess the dependence of CDs on cluster type and the latters incremental prognostic value over conventional risk factors. ResultsThree male clusters were optimally identified (M1-M3): M1 was associated with small valve leaflet calcification loads and aortic root dimensions; both M2 and M3 were associated with large valve leaflet calcification loads and a wide aortic root, but the aortic root was shorter in M2 than M3. Two female clusters were optimally determined (F1-F2): F2 was associated with larger valve leaflet calcification loads and aortic root dimensions. By logistic regression analysis, compared to M1 (reference), M2, but not M3, was more associated with CDs (ORM2/M1=2.15, P=0.032; ORM3/M1=2.12, P=0.085), with no difference between M3 and M2 (ORM3/M2=0.986, P=0.974) or between F1 and F2 (ORF2/F1=1.294, P=0.581). Including cluster type as a predictor in a regression model of CDs containing conventional risk factors as covariates improved the goodness-of-fit (P=0.020). ConclusionsUML of pre-TAVR CTAs can reveal subgroups of male patients with differential risks for CDs and improve prognostication over conventional risk factors. UML-augmented pre-TAVR CTAs may help better guide personalized strategies to minimize CDs.