Daily Cardiology Research Analysis
Analyzed 59 papers and selected 3 impactful papers.
Summary
Analyzed 59 papers and selected 3 impactful articles.
Selected Articles
1. BCKDK protects against obesity-induced cardiac remodelling and dysfunction by alleviating mitochondrial oxidative stress and ROS-driven MAPK signalling.
Cardiomyocyte-specific BCKDK deletion worsened obesity cardiomyopathy despite lowering myocardial BCAA levels, whereas BCKDK overexpression improved function and remodelling. Protection was linked to reduced mitochondrial oxidative stress and suppression of ROS-driven MAPK signaling, independent of BCAA levels. MitoTEMPO rescued dysfunction and MAPK activation induced by BCKDK deficiency, identifying BCKDK as a cardiomyocyte-intrinsic therapeutic target.
Impact: This study overturns assumptions from systemic BCKDK inhibition by revealing a cardiomyocyte-intrinsic, BCAA-independent protective role via mitochondrial ROS control. It reframes therapeutic strategies for obesity cardiomyopathy toward cell-specific modulation.
Clinical Implications: Therapeutics targeting BCKDK should consider cell-specific effects; systemic inhibition may not reproduce cardiomyocyte benefits and could be counterproductive. Targeting mitochondrial ROS and downstream MAPK may offer adjunctive strategies in obesity cardiomyopathy.
Key Findings
- Cardiomyocyte-specific BCKDK deletion exacerbated cardiac dysfunction and remodelling in obesity cardiomyopathy despite reduced myocardial BCAA.
- BCKDK overexpression improved function and remodelling, attenuated mitochondrial oxidative stress, and suppressed MAPK-driven inflammatory signaling.
- MitoTEMPO rescued mitochondrial dysfunction and reversed MAPK activation in BCKDK-deficient settings, indicating a BCAA-independent mechanism.
Methodological Strengths
- Use of cardiomyocyte-specific knockout and overexpression mouse models with multi-omics profiling
- Mechanistic rescue experiments with mitochondrial ROS scavenger (MitoTEMPO)
Limitations
- Preclinical mouse models may not fully translate to human disease
- Sample sizes and effect sizes per subgroup are not specified in the abstract
Future Directions: Validate cardiomyocyte-targeted BCKDK modulation in large animal models and human tissues; test mitochondrial ROS/MAPK-targeted combinatorial therapies; dissect extracardiac contributions to benefits of systemic BCKDK inhibition.
AIMS: Impaired branched-chain amino acid (BCAA) catabolism has been implicated in obesity cardiomyopathy (OCM), and systemic inhibition of branched-chain ketoacid dehydrogenase kinase (BCKDK), a key negative regulator of BCAA oxidation, improves cardiac function. However, whether cardiomyocyte-specific manipulation of BCAA catabolism is sufficient to confer cardioprotection remains unknown. METHODS AND RESULTS: Cardiomyocyte-specific BCKDK knockout and overexpression mouse models were generated and subjected to high-fat diet feeding, followed by echocardiography, transcriptomic, metabolomic, and molecular analyses. The mechanistic findings were further validated using in vitro experiments.
2. Gut microbiota-associated leucine elevation promotes cold-induced atherosclerotic plaque formation and instability.
Cold exposure remodeled gut microbiota to raise circulating leucine, which suppressed macrophage Zic2, downregulated Gas6, impaired efferocytosis, and increased vascular inflammation and plaque instability. Supplementation with Lactobacillus johnsonii normalized leucine, restored Zic2–Gas6 signaling, enhanced efferocytosis, and attenuated plaque progression, while leucine supplementation mimicked cold effects.
Impact: Defines a novel cold–microbiota–leucine–Zic2–Gas6–efferocytosis axis linking environmental stress to atherosclerosis, offering actionable microbiome and metabolic targets. Demonstrates reversibility with a specific commensal bacterium.
Clinical Implications: Highlights potential for microbiota-based or amino acid–modulating interventions (e.g., Lactobacillus johnsonii) to mitigate cold-associated atherosclerotic risk. Suggests environmental context should inform preventive cardiology strategies.
Key Findings
- Cold exposure accelerated plaque growth and instability alongside gut dysbiosis and host metabolic shifts in ApoE−/− mice.
- Cold-associated microbiota elevated circulating leucine; leucine suppressed macrophage Zic2, reduced Gas6, impaired efferocytosis, and increased inflammation.
- Lactobacillus johnsonii supplementation normalized leucine, restored Zic2–Gas6 signaling, enhanced efferocytosis, and reduced plaque progression; exogenous leucine recapitulated cold effects.
Methodological Strengths
- Integrated multi-omics with fecal microbiota transplantation and mechanistic cell assays
- Interventional validation using a specific commensal (Lactobacillus johnsonii) and amino acid supplementation
Limitations
- Findings are in mouse models; human validation is needed
- Specificity to cold exposure context may limit generalizability across environments
Future Directions: Validate axis components (leucine, Zic2, Gas6) in human cohorts exposed to cold; test L. johnsonii or leucine-modulating strategies in preclinical-to-clinical translation; delineate microbial producers and dietary influences.
BACKGROUND: Environmental factors such as cold exposure have been increasingly recognized as contributors to atherosclerosis progression, yet the underlying mechanisms linking environmental stress to vascular pathology remain incompletely understood. In particular, the role of the gut microbiota and microbiota-associated metabolites in cold-induced atherosclerosis has not been fully elucidated. METHODS: A cold exposure model was established in ApoE⁻/⁻ mice fed a Western diet. Integrated multi-omics analyses were combined with fecal microbiota transplantation (FMT) and mechanistic cellular assays to investigate gut microbiota remodeling, metabolic alterations, and immune regulation during cold-induced atherosclerosis. RESULTS: In this study, we demonstrate that cold exposure accelerates atherosclerotic plaque growth and instability in parallel with pronounced gut microbiota dysbiosis and alterations in host metabolic profiles. FMT combined with metabolomic analyses showed that cold-associated gut microbiota is closely associated with elevated circulating leucine levels, suggesting that cold-induced microbial remodeling may participate in this process by modulating host systemic leucine availability.
3. Normal standardized left ventricular longitudinal strain curves stratified by age and sex in healthy individuals: The Copenhagen City Heart Study.
Sex- and age-specific normal LV longitudinal strain curves were derived, revealing age-related decreases in early diastolic strain (EDS) and increases in late diastolic strain (LDS). Novel metrics, particularly mean strain deviation, provided prognostic information for cardiovascular death or incident heart failure/atrial fibrillation beyond conventional measures and were externally validated in the LOOP study. Code and normal curves are publicly available.
Impact: Provides standardized reference strain curves with open resources and demonstrates prognostic utility of novel curve-derived metrics, facilitating harmonized echocardiographic risk stratification.
Clinical Implications: Clinicians can benchmark patient strain curves against sex- and age-specific normals and consider integrating mean strain deviation into risk assessment for cardiovascular events. Standardized curves and shared code support reproducible implementation across centers.
Key Findings
- Established sex- and age-specific normal LV longitudinal strain curves in 1,641 healthy CCHS participants and externally validated in 1,307 LOOP participants.
- Early diastolic strain (EDS) decreased with age while late diastolic strain (LDS) increased, quantifying curve morphology changes across lifespan.
- Mean strain deviation independently predicted a composite of cardiovascular death or incident heart failure/atrial fibrillation (adjusted HR 1.02; p=0.045).
Methodological Strengths
- Large, well-characterized healthy cohort with external validation
- Derivation of novel, curve-based metrics with publicly available code enabling reproducibility
Limitations
- Effect sizes for prognostic metrics were modest (e.g., HR 1.02), requiring further validation
- Generalizability across vendors/protocols and younger external populations needs assessment
Future Directions: Validate curve-derived metrics across vendors and diverse populations; assess additive value over biomarkers and imaging; integrate into automated strain analysis workflows.
AIMS: To establish normal sex- and age-specific longitudinal strain curves, to quantify their morphological variation with age, and to demonstrate their utility by deriving novel measures from them with the aim of testing prognostic value. METHODS AND RESULTS: Age- and sex-appropriate normal strain curves were derived from healthy participants of the Copenhagen City Heart Study (CCHS). Four novel measures were constructed: early (EDS) and late (LDS) diastolic strain, primarily to assess age-related variation in strain curve morphology, and mean and diastolic strain deviation. Their prognostic value was assessed using Cox proportional hazards regression and C-statistics internally in the CCHS and externally in the LOOP study against a composite endpoint of cardiovascular death and incident heart failure or atrial fibrillation.In total, 1,641 healthy subjects (mean±SD age 45.3±15.2 years, 62.3% female) from the CCHS and 1,307 (mean±SD age 74.4±4.0 years, 47.4% female) from the LOOP study were included. EDS decreased with age while LDS increased. During a median follow-up of 4.9 [IQI: 3.0, 5.6] years, 409 (31.3%) subjects met the outcome in the LOOP study. Mean strain deviation was independently associated with the outcome (adjusted HR = 1.02 (95% CI: 1.00, 1.05), p = 0.045), while diastolic strain deviation was not. CONCLUSION: We established normal sex- and age-specific longitudinal strain curves and furthermore demonstrated their utility by deriving novel measures from these with prognostic value beyond conventional measures. While promising, further validation in external populations is warranted. The normal curves and relevant code are publicly available.