Daily Cardiology Research Analysis
Analyzed 163 papers and selected 3 impactful papers.
Summary
Three impactful cardiology studies stood out today: a pragmatic randomized trial found that an ESC 0/1-hour high-sensitivity troponin pathway did not improve 4-hour ED discharge rates versus a 0/3-hour pathway despite noninferior safety; a Nature Communications study revealed how rare LMNA variants interact with common polymorphisms to drive atrial fibrillation via chromatin and electrophysiologic remodeling; and a multicenter registry showed residual myocardium at risk (rBCIS-JS >4) predicts worse outcomes after TAVI.
Research Themes
- Implementation trials of accelerated diagnostic pathways in emergency cardiology
- Gene–environment and gene–polygenic interactions in arrhythmia pathogenesis
- Coronary disease burden and revascularization strategy in TAVI candidates
Selected Articles
1. Accelerated Diagnostic Pathways for Suspected Acute Coronary Syndrome in Practice: A Randomized Trial of 0/1-Hour vs 0/3-Hour Troponin Testing.
In a pragmatic randomized implementation trial of 3,543 ED patients with suspected ACS, the ESC 0/1-hour hs-troponin pathway did not increase 4-hour discharges compared with a 0/3-hour pathway, though discharge safety was noninferior. Central laboratory turnaround time and operational constraints likely mitigated expected efficiency gains.
Impact: This head-to-head randomized implementation trial directly informs ED diagnostic pathways, challenging assumptions that 0/1-hour sampling alone improves throughput.
Clinical Implications: Adopting a 0/1-hour hs-troponin pathway may not improve ED throughput without addressing lab turnaround and system bottlenecks; safety appears maintained. Programs should consider point-of-care assays, optimized logistics, and integrated workflows rather than sampling interval alone.
Key Findings
- 0/1-hour hs-cTn pathway did not significantly increase 4-hour discharge rates versus 0/3-hour (21.8% vs 19.2%; P=0.07).
- Discharge safety was noninferior for 0/1-hour vs 0/3-hour, with higher point-estimate sensitivity (93.7% vs 89.5%).
- Median central laboratory hs-cTnT turnaround time was 81 minutes, likely blunting efficiency gains from earlier sampling.
Methodological Strengths
- Pragmatic randomized, noninferiority design with 100% follow-up via national hospital capture.
- Independent hs-cTnI adjudication to avoid incorporation bias and standardized MACE outcomes at 30 days.
Limitations
- Conducted in two EDs within one region; generalizability may vary across systems and assay platforms.
- Central lab turnaround times and ED operational constraints may have masked potential efficiency benefits.
Future Directions: Evaluate point-of-care hs-cTn testing, streamlined logistics, and digital decision-support alongside 0/1-hour pathways; test outcomes in diverse health systems and integrate patient flow metrics.
BACKGROUND: For suspected acute coronary syndrome (ACS), guidelines recommend using high-sensitivity troponins (hs-cTn) in accelerated diagnostic pathways (ADPs) with 0/1-hour recommended over 0/3-hour ADP. However, implementation of these ADPs, with universal use of hs-cTns, has not been directly compared in randomized trials OBJECTIVES: This study sought to compare the efficiency and safety of the European Society of Cardiology (ESC) 0/1-hour and a 0/3-hour ADP when implemented in real-world clinical practice. METHODS: This pragmatic, randomized, noninferiority implementation trial compared the safety and efficiency of clinician decision making using these 2 pathways. To prevent incorporation bias, an independent hs-cTnI was used for formal adjudication using the fourth universal definition of myocardial infarction (MI). Efficiency was judged by the proportion of patients discharged within 4 hours. The safety endpoint was major adverse cardiac events (MACE) within 30 days (adjudicated index or representation type 1 MI, cardiovascular death, and urgent coronary revascularization) for those who were considered not to have ACS and discharged. The noninferiority margin, for absolute difference in sensitivity, between the ESC 0/1-hour and the 0/3-hour ADP was set at 3%, assessed with a 1-sided 97.5% CI. RESULTS: From December 2021 to July 2024, of 13,983 screened 3,543 individual patients with suspected ACS were recruited and consented from 2 major emergency departments in North-West England, with 100% follow-up achieved for all representations to any national hospital. The median age was 60 years (IQR: 49.5-70.5 years), 53% were men, 6.9%, and 7.8% had adjudicated index type 1 MI and MACE within 30 days, respectively. The turnaround time from sample to result for central laboratory hs-cTnT was 81 minutes (IQR: 69-101 minutes). The proportion of patients discharged within 4 hours was relatively low and did not differ substantially (21.8% vs 19.2%, P = 0.07). In addition, the 0/1-hour pathway was noninferior for safety, in patients discharged, compared with the 0/3-hour pathway, absolute difference in sensitivity was +4.2% (1-sided 97.5% CI: -2.5) in favor of the 0/1-hour pathway. The calculated sensitivities were 93.7% (95% CI: 88.4%-97.1%) vs 89.5% (95% CI: 82.7%-94.3%), respectively. CONCLUSIONS: Implementation of the ESC 0/1-hour pathway failed to discharge significantly more patients within 4 hours of presentation compared with the 0/3-hour ADP. In addition, The ESC 0/1-hour was noninferior to the 0/3-hour hs-cTn pathway for safety of discharge, although safety for both pathways was less than that imputed by observational studies. This trial demonstrates that perceived benefits to emergency department efficiency of a reduced sampling interval are mitigated by central laboratory turnaround times as well as system constraints. (Pragmatic Randomised Trial of the ESC 0/1 Versus 0/3 Hour Troponin Pathway [MACROS2]; NCT05322395).
2. Gene-gene interactions between a LMNA variant and common polymorphisms drive early-onset atrial fibrillation.
Across two large cohorts, LMNA protein-altering variants amplify AF risk beyond polygenic risk alone. iPSC-derived atrial cardiomyocytes carrying LMNA variants show disrupted chromatin and atrial regulatory networks; CRISPR editing validates AF-associated enhancers, including an SCN10A element where reduced accessibility links to diminished sodium current.
Impact: This work uncovers a mechanistic bridge between rare LMNA variants and common AF polymorphisms, integrating human cohorts with functional genomics to explain early-onset AF susceptibility.
Clinical Implications: Combining rare variant analysis with AF PRS could refine individualized risk stratification and surveillance. Targeting specific regulatory elements or pathways (e.g., sodium current modulation) may emerge as precision therapeutic strategies, though translation requires further validation.
Key Findings
- LMNA protein-altering variant carriers exhibit higher incident AF risk than predicted by polygenic risk alone in UK Biobank and All of Us.
- LMNA p.S143P iPSC-atrial cardiomyocytes show widespread chromatin and regulatory network disruption at AF-associated loci.
- CRISPR-based epigenetic editing validates AF enhancers; reduced accessibility at an intronic SCN10A enhancer (rs6801957) correlates with reduced sodium current.
Methodological Strengths
- Integration of population-scale PRS with functional validation in patient-derived iPSC-atrial cardiomyocytes.
- CRISPR-based epigenetic perturbation to causally test regulatory elements; replication in an additional LMNA variant background.
Limitations
- In vitro iPSC models may not fully recapitulate adult atrial physiology and environmental modifiers.
- Sample sizes for specific rare variant carriers are limited; findings require validation across diverse ancestries.
Future Directions: Prospective studies integrating rare variants and PRS for AF screening; in vivo validation of regulatory element function and therapeutic modulation of implicated pathways (e.g., sodium channel regulation).
Atrial fibrillation (AF), the most common sustained arrhythmia, has a complex genetic basis; however, the molecular mechanisms linking rare and common variants remain poorly understood. Polygenic risk score (PRS) analysis in the UK Biobank and All of Us cohorts reveals that carriers of protein-altering LMNA variants (PAVs) have a significantly higher risk of incident AF than predicted by PRS alone, supporting an additive effect of common polymorphisms and LMNA variants. Induced pluripotent stem cell derived atrial cardiomyocytes (iPSC-aCMs) from individuals carrying the pathogenic missense variant p.S143P in LMNA exhibit widespread disruption of chromatin architecture and perturbation of atrial gene regulatory networks, particularly at loci harboring AF-associated variants and transcription factors essential for atrial rhythm control and contractility. Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-based epigenetic editing validates the function of several AF-associated regulatory elements and their downstream targets. Notably, reduced accessibility at an intronic SCN10A enhancer harboring the AF-associated SNP rs6801957 is associated with reduced sodium current in p.S143P iPSC-aCMs. These findings are reproduced in iPSC-aCMs derived from an additional individual carrying a distinct pathogenic LMNA variant, supporting a broader mechanism in which rare LMNA variants and common polymorphisms converge on shared regulatory networks to influence AF susceptibility and highlighting the value of integrating both in arrhythmia risk assessment.
3. Clinical Impact of Myocardium at Risk in Transcatheter Aortic Valve Implantation.
In the multicenter REVASC-TAVI registry, residual myocardium at risk quantified by rBCIS-JS after planned PCI around TAVI predicted outcomes: rBCIS-JS >4 was associated with substantially higher 2-year MACCE compared with rBCIS-JS ≤4, even after propensity matching.
Impact: The study provides a practical, quantitative metric (rBCIS-JS) to guide coronary revascularization strategy in TAVI candidates and links residual ischemic burden to clinically relevant 2-year outcomes.
Clinical Implications: Pre-TAVI planning should minimize residual myocardium at risk (target rBCIS-JS ≤4) via appropriately timed and selected PCI; heart teams can use rBCIS-JS to stratify risk and personalize revascularization timing before, during, or after TAVI.
Key Findings
- In 2,407 TAVI patients, propensity-matched analysis (294 pairs) showed higher 2-year MACCE with rBCIS-JS >4 versus ≤4.
- Planned PCI (before/during/within 1 month after TAVI) with lower residual ischemic burden was associated with improved outcomes.
- rBCIS-JS operationalizes residual myocardium at risk as a prognostic tool in TAVI patients with CAD.
Methodological Strengths
- Large international multicenter registry with prespecified risk quantification using BCIS-JS.
- Propensity score matching to balance clinical covariates between high and low rBCIS-JS groups.
Limitations
- Observational design with potential residual confounding; no randomization of revascularization strategy.
- BCIS-JS is an anatomical surrogate and does not directly measure ischemia or viability.
Future Directions: Prospective trials randomizing revascularization strategies guided by rBCIS-JS and physiology; integration with FFR/iFR and perfusion imaging to refine thresholds and timing.
BACKGROUND: The best management of coronary artery disease in patients with severe aortic stenosis undergoing transcatheter aortic valve implantation (TAVI) is debated. We investigated the clinical impact of the residual extent of myocardium at risk in patients undergoing TAVI. METHODS: Patients enrolled in the REVASC-TAVI (Management of Myocardial Revascularization in Patients Undergoing TAVI With Coronary Artery Disease) international multicenter registry were stratified according to the myocardium jeopardized by coronary artery disease using the British Cardiovascular Intervention Society Jeopardy Score (BCIS-JS) after a planned coronary revascularization. A planned revascularization included percutaneous coronary interventions performed before TAVI, during TAVI, or within 1 month after TAVI. The study population was divided according to the residual BCIS-JS (rBCIS-JS): patients with extensive residual myocardial at risk (rBCIS-JS >4 group) and patients without extensive residual myocardial at risk (rBCIS-JS ≤4 group). The primary study end point was the composite of all-cause death, nonfatal myocardial infarction, nonfatal stroke, and rehospitalization for heart failure at 2 years. RESULTS: Among the 2407 patients enrolled, 294 pairs of patients were selected by propensity matching and compared. At 2-year follow-up, the incidence of the primary end point was higher in patients with rBCIS-JS >4 compared with patients with rBCIS-JS ≤4 (37.5% versus 23.0%, CONCLUSIONS: In patients with concomitant coronary artery disease and severe aortic stenosis, the residual myocardial risk significantly affects TAVI outcomes. In particular, a rBCIS-JS >4 is associated with higher rates of major adverse cardiac and cerebrovascular events at 2 years.