Daily Cardiology Research Analysis
Analyzed 143 papers and selected 3 impactful papers.
Summary
Analyzed 143 papers and selected 3 impactful articles.
Selected Articles
1. Integrating Genomics and Proteomics to Identify Causal Proteins and Biologic Pathways for Incident Atrial Fibrillation in CKD.
Across two CKD cohorts profiled for 4,590 plasma proteins, Mendelian randomization implicated NELL1, CILP2, and MMP12 as causal for incident AF, with substantial pathway overlap between AF and left atrial enlargement. A multi-protein risk score achieved annualized AUCs of 0.65–0.76 over 5 years, comparable to CHARGE-AF.
Impact: This work links CKD biology to AF via causal proteins and delivers a validated proteomic risk tool, opening avenues for precision prevention and target discovery.
Clinical Implications: Proteomic risk stratification could complement clinical scores in CKD to identify high-risk patients for rhythm monitoring or preventive strategies, and the causal proteins offer candidate therapeutic targets.
Key Findings
- Three proteins (NELL1, CILP2, MMP12) were causally linked to incident AF by Mendelian randomization.
- Eight of the top ten pathways overlapped between incident AF and left atrial enlargement.
- A proteomic risk score for AF achieved annualized AUCs of 0.65–0.76 over 5 years, comparable to CHARGE-AF.
- Findings were replicated across two CKD cohorts (CRIC n=2,654; ARIC n=1,326) with 290 incident AF events.
Methodological Strengths
- Large multi-cohort proteomics with external validation and Mendelian randomization for causal inference
- Integration of echocardiographic left atrial size and pathway analyses to link substrate and biomarkers
Limitations
- Observational design with residual confounding; MR assumptions may be violated in CKD context
- Generalizability limited to CKD; risk score AUCs are modest and require prospective utility testing
Future Directions: Prospective, biomarker-guided screening and intervention trials in CKD enriched by the proteomic score; mechanistic validation and druggability assessment of NELL1, CILP2, and MMP12.
BACKGROUND: Chronic kidney disease (CKD) is strongly associated with atrial fibrillation. Understanding the biological pathways for this association and creating predictive models has been challenging. Left atrial enlargement is a substrate for atrial fibrillation but any overlap between biomarkers of atrial fibrillation and left atrial enlargement in individuals with CKD is unknown. METHODS: We evaluated 4,590 plasma proteins with SomaScan in two cohorts of adults with CKD: the Chronic Renal Insufficiency Cohort (CRIC, n=2,654) and the Atherosclerosis Risk in Communities Cohort (ARIC, n=1,326). Using Mendelian randomization, we identified proteins along the causal pathway to atrial fibrillation. We also identified proteins and corresponding pathways associated with larger echocardiographic left atrial size, a recognized substrate for atrial fibrillation. Lastly, we developed and validated a multi-protein risk score for incident atrial fibrillation in the CKD population. RESULTS: Over five years, incident atrial fibrillation occurred among 150 individuals in CRIC and 140 in ARIC. We identified three proteins causally linked to incident atrial fibrillation: neural epidermal growth factor like (NEL)-like protein 1 (NELL1), cartilage intermediate layer protein 2 (CILP2), and matrix metallopeptidase 12 (MMP12). Pathway analysis revealed an overlap in 8 of the top 10 canonical pathways for incident atrial fibrillation and left atrial enlargement. A risk model for incident atrial fibrillation comprised of proteins had annualized AUCs over 5 years ranging from 0.65 to 0.76, a performance similar to the Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE AF) clinical risk score. CONCLUSIONS: This study identified causal proteins and biological mechanisms underlying incident atrial fibrillation in CKD. A proteomic risk score for incident atrial fibrillation in CKD performed similarly to CHARGE-AF.
2. From Constraint to Opportunity: 10°C Static Cold Storage Allows Prolonged Ischemic Time and Attenuates Severe Primary Graft Dysfunction Risk in Adult Heart Transplantation.
In a retrospective single-center cohort of 506 adult heart transplants, 10°C static cold storage attenuated the rise in severe primary graft dysfunction risk typically seen with longer ischemic times. Despite longer ischemic times and older donors, 10°C storage yielded lower PGD odds at 4 hours and a net risk reduction versus ice, supported by weighted regression, g-computation, and mediation analyses.
Impact: This study challenges the long-held 4-hour transport constraint by showing 10°C storage can safely extend ischemic time with improved early graft performance. It has immediate implications for donor allocation and logistics in heart transplantation.
Clinical Implications: Programs could adopt controlled 10°C static cold storage to expand donor catchment areas, reduce severe PGD, and improve early graft function, warranting multicenter prospective trials and protocolized implementation.
Key Findings
- Each additional hour of ischemia with ice storage increased odds of severe PGD by 2.7-fold (p<0.001).
- At 4 hours, 10°C storage was associated with markedly lower odds of severe PGD versus ice (OR 0.21; 95% CI 0.09–0.45; p<0.001), flattening the ischemic risk curve.
- In grafts with ischemic time >4 hours, 10°C corresponded to a 90.9% relative risk reduction in severe PGD (95% CI 59.7–99.5).
- Causal mediation estimated a 3.5 percentage-point net reduction in severe PGD for 10°C vs ice (95% CI −7.7 to −0.2; p=0.042).
- Despite older donors and longer ischemic times in the 10°C group, early outcomes were overall similar or improved compared with ice.
Methodological Strengths
- Large single-center cohort (n=506) with detailed perioperative phenotyping
- Advanced causal inference (weighted regression, g-computation, mediation analysis) and prespecified subgroup analyses
Limitations
- Retrospective, single-center design with potential residual confounding and selection bias
- Short-term outcomes (30–90 days); no randomized allocation to storage strategy
Future Directions: Conduct multicenter prospective trials comparing 10°C vs ice SCS with standardized allocation criteria, longer-term outcomes, and cost-effectiveness analyses.
BACKGROUND: Allograft ischemic time remains a major constraint in heart transplantation, with ice-based static cold storage (SCS) limiting safe transport to 4 hours. We evaluated whether 10°C SCS alters the relationship between ischemic time and early cardiac allograft function in a contemporary single-center cohort. METHODS: We retrospectively analyzed adult heart transplants performed from January 2020 to June 2025. Only allografts preserved with SCS (ice or 10°C) were included; multiorgan and complex congenital transplants were excluded. The primary exposure was preservation strategy (ice vs 10°C) and total allograft ischemic time. The primary outcome was severe primary graft dysfunction (PGD); secondary outcomes included early biventricular function, vasoactive inotrope score, renal replacement therapy, length of stay, and 30- and 90-day mortality. Weighted regression assessed the effect of ischemic time and its interaction with storage type on severe PGD. In a prespecified subgroup with ischemic time >4 hours, g-computation estimated counterfactual risks if all grafts had been stored at 10°C. Regression-based causal mediation analysis quantified the net effect of prolonged ischemic time with 10°C SCS on severe PGD. RESULTS: Among 506 recipients (median age 58.3 years; 25.5% female), 40.9% received 10°C-preserved grafts and 59.1% received ice-preserved grafts. Compared with ice, the 10°C cohort more often received hearts from older donors (36.0 vs 29.9 years; p<0.001) with longer ischemic times (235 vs 202 minutes; p<0.001), yet early outcomes were similar overall. In weighted models, each additional hour of ischemia in ice-preserved grafts increased the odds of severe PGD by 2.7-fold (p<0.001). At 4 hours of ischemic time, 10°C storage was associated with markedly lower odds of severe PGD compared with ice (OR 0.21; 95% CI 0.09-0.45; p<0.001) and the ischemic time risk curve flattened in 10°C cohort. In the ischemic time >4-hour subgroup, 10°C corresponded to a relative risk reduction in severe PGD of 90.9% (95% CI 59.7-99.5). Mediation analysis estimated a net risk reduction in severe PGD of 3.5 percentage points for 10°C vs ice (95% CI -7.7 to -0.2; p=0.042) despite accumulating high ischemic time risk. CONCLUSIONS: In this contemporary cohort, 10°C SCS decoupled the traditional link between prolonged ischemic time and severe PGD. 10°C preservation conferred a net reduction in severe PGD and improved early graft performance compared with ice in adult heart transplantation.
3. Unrestrained fatty acid oxidation triggers heart failure in mice via cardiolipin loss and mitochondrial dysfunction.
Cardiomyocyte-specific ACC1/2 deletion elevated FAO, depleted linoleic acid–derived cardiolipin, impaired ETC activity, and caused dilated cardiomyopathy. FAO inhibitors (etomoxir, oxfenicine) restored cardiolipin and ETC function and prevented heart failure, indicating that stimulating cardiac FAO may be harmful.
Impact: This study uncovers a mechanistic link between unrestrained FAO, cardiolipin loss, and mitochondrial failure leading to heart failure, and demonstrates pharmacologic rescue—informing metabolism-targeted strategies.
Clinical Implications: Therapies that indiscriminately boost cardiac FAO may be detrimental; conversely, selective FAO modulation restoring cardiolipin homeostasis could be cardioprotective and merits translational evaluation.
Key Findings
- ACC1/2 double-knockout mice exhibited constitutively elevated FAO and developed dilated cardiomyopathy and heart failure.
- Lipidomics showed marked cardiolipin depletion due to reduced linoleic acid, impairing ETC activity and mitochondrial function.
- FAO inhibition with etomoxir or oxfenicine restored cardiolipin, normalized ETC activity, and prevented cardiac dysfunction.
Methodological Strengths
- Genetic loss-of-function model with multi-omics (lipidomics) and functional mitochondrial assessments
- Pharmacologic rescue using two mechanistically distinct FAO inhibitors strengthens causal inference
Limitations
- Findings are in murine models; human translational relevance requires validation
- Potential off-target effects of FAO inhibitors like etomoxir need careful consideration
Future Directions: Translate to human myocardium studies (biopsies, iPSC-CMs) to validate cardiolipin dynamics; evaluate selective FAO modulators and cardiolipin-stabilizing strategies in large-animal and early-phase trials.
Cardiomyocytes primarily rely on fatty acid oxidation (FAO), which provides more than 70% of their energy. However, excessive FAO can disrupt cardiac metabolism by increasing oxygen demand and suppressing glucose utilization through the Randle cycle. Although inhibition of FAO has been investigated in heart failure, its overall therapeutic impact remains uncertain. To determine the consequences of enhanced FAO, we generated cardiomyocyte-specific ACC1 and ACC2 double-knockout (ACC dHKO) mice, which exhibit constitutively elevated FAO. ACC dHKO mice developed dilated cardiomyopathy and heart failure. Lipidomic analysis revealed marked depletion of cardiolipin caused by reduced linoleic acid, a direct consequence of excessive FAO. This cardiolipin deficiency impaired mitochondrial electron transport chain (ETC) activity, leading to mitochondrial dysfunction. Pharmacologic inhibition of FAO with etomoxir or oxfenicine restored cardiolipin levels, normalized ETC activity, and prevented cardiac dysfunction in ACC dHKO mice. These findings demonstrate that unrestrained FAO disrupts both lipid and energy homeostasis, culminating in heart failure in this model. Collectively, these results indicate that although FAO is essential for cardiac energy production, therapeutic strategies aimed at stimulating cardiac FAO may be detrimental rather than beneficial in heart failure.