Daily Cardiology Research Analysis
Three impactful cardiology studies stand out today: a translational electrophysiology study identifies Piezo2 in cardiac ganglionated plexi as a novel atrial fibrillation target; a systems-of-care registry from a middle-income country shows that adopting Cardiogenic Shock Working Group standards substantially reduces mortality; and a multicenter CMR cohort defines right-ventricular volume/function thresholds that stratify risk in severe tricuspid regurgitation.
Summary
Three impactful cardiology studies stand out today: a translational electrophysiology study identifies Piezo2 in cardiac ganglionated plexi as a novel atrial fibrillation target; a systems-of-care registry from a middle-income country shows that adopting Cardiogenic Shock Working Group standards substantially reduces mortality; and a multicenter CMR cohort defines right-ventricular volume/function thresholds that stratify risk in severe tricuspid regurgitation.
Research Themes
- Neurocardiac mechanisms and novel therapeutic targets in atrial fibrillation
- Systems-level improvement in cardiogenic shock care and outcomes
- Imaging-based risk stratification in severe tricuspid regurgitation
Selected Articles
1. Piezo2 expressed in ganglionated plexi: Potential therapeutic target of atrial fibrillation.
Piezo2 is upregulated in cardiac ganglionated plexi in AF and with higher left atrial pressure; targeted knockdown of Piezo2 in GP reduces neural activity and AF susceptibility in a large-animal model. Transcriptomics implicated Notch pathway downregulation, supporting a mechanistic link between mechanosensation and autonomic modulation in AF.
Impact: This study identifies a mechanosensitive ion channel in human cardiac GP and demonstrates causal modulation of AF in a large-animal model, opening a new neuromodulatory therapeutic avenue beyond current ablation strategies.
Clinical Implications: Piezo2 in GP could be targeted pharmacologically or via gene modulation to reduce AF susceptibility, informing future device- or bio-therapies and potentially refining patient selection for GP ablation.
Key Findings
- Piezo2 expression in cardiac ganglionated plexi is increased in AF and with higher left atrial pressure.
- AAV-mediated Piezo2 knockdown in GP reduces neural activity and lowers AF inducibility in a large-animal rapid pacing model.
- RNA-seq implicates downregulation of the Notch signaling pathway following Piezo2 knockdown, suggesting mechanistic links.
Methodological Strengths
- Human GP tissue analyses combined with large-animal functional experiments.
- Multimodal assessment including electrophysiology, neural activity, and RNA sequencing.
Limitations
- Translational gap remains; no first-in-human interventional targeting of Piezo2.
- Long-term safety and specificity of GP-targeted gene modulation are unknown.
Future Directions: Develop selective Piezo2 modulators or neuromodulation strategies; evaluate efficacy/safety in chronic large-animal models and design early-phase human trials integrating autonomic and electrophysiologic endpoints.
BACKGROUND: Atrial fibrillation (AF) is closely linked to autonomic nervous system activity, with activation of the cardiac ganglionated plexi (GP) often present in AF. Piezo, a mechanosensitive ion channel, plays a pivotal role in neuronal modulation. However, its involvement in the GP and AF remains poorly understood. OBJECTIVE: This study investigated the expression of Piezo2 in GP and its potential role in AF. METHODS: GP tissues were collected from patients undergoing cardiac transplantation, and Piezo expression levels were assessed. Rapid atrial pacing was performed in a large-animal model to induce AF, and Piezo expression in GP tissues was also evaluated. Piezo2 knockdown in GP was achieved by adeno-associated virus in animals subjected to rapid atrial pacing. Atrial electrophysiologic parameters, AF inducibility, neural activity, and GP function were subsequently analyzed. RNA sequencing was employed to elucidate underlying mechanisms. RESULTS: In the AF group and in people with higher left atrial pressure, Piezo2 expression was increased in the GP. Knockdown of Piezo2 in GP impaired GP function and neural activity, thereby decreasing AF susceptibility. RNA sequencing analysis revealed significant downregulation of the Notch signaling pathway. CONCLUSION: These findings suggest that Piezo2 expressed in GP may serve as a novel therapeutic target for the treatment of AF.
2. International cooperation in cardiogenic shock is key to improving outcomes: Cardiogenic Shock Working Group impacts a single center in a developing country.
Implementing CSWG standards at a middle-income country reference center increased use of invasive hemodynamics and mechanical circulatory support and reduced mortality from ~21–22% to 15%. Adjusted analyses (Cox, propensity matching) support a system-level benefit of standardized CS teams and protocols.
Impact: Demonstrates real-world mortality reduction through standardized CS care in a resource-constrained setting, offering a scalable model for global adoption.
Clinical Implications: Hospitals should consider adopting CS team-based protocols, including early invasive hemodynamic monitoring and judicious use of mechanical circulatory support, to improve outcomes.
Key Findings
- Adoption of CSWG standards increased pulmonary artery catheter use to 7.9% and MCS to 10.3% in the implementation era.
- In-hospital mortality decreased from 22.3%/20.5% (pre-CSWG eras) to 15.3% (CSWG era), p < 0.001.
- Adjusted hazard ratios favored the CSWG era: historical cohort HR 1.22 (p = 0.015) and contemporary cohort HR 1.20 (p = 0.047) for mortality versus CSWG era.
Methodological Strengths
- Large real-world registry with 9,430 CS patients spanning 18 years.
- Use of multivariable Cox regression and propensity score matching to mitigate confounding.
Limitations
- Before-after observational design susceptible to secular trends and unmeasured confounding.
- Protocol adherence and device selection nuances across eras are not fully detailed.
Future Directions: Prospective multicenter implementation trials to validate generalizability; define optimal hemodynamic-guided algorithms and MCS escalation pathways in diverse health systems.
The Cardiogenic Shock Working Group (CSWG) is an international research consortium formed in 2016. The National Institute of Cardiology Ignacio Chavez joined in 2021 and launched a cardiogenic shock (CS) program in 2022. This study evaluates the impact of CSWG core standards on outcomes in a middle-income country reference center of 9,430 patients with CS (Society for Cardiovascular Angiography and Interventions [SCAI] stages B→E) from a registry of 28,054 admissions (2005-2023). Using multivariate Cox regression and propensity score matching, outcomes were compared between historic pre-CSWG (2005-2021) and contemporary pre-CSWG (2017-2021) eras vs the CSWG era (2022-2023). Adoption of CS-team standards increased the use of pulmonary artery catheters (4.2%, 4% vs 7.9%, p < 0.001) and mechanical circulatory support devices (8.1% to 10.3%, p = 0.014) only in the legacy era. Reducing mortality from 22.3% and 20.5% vs 15.3% (p < 0.001). The adjusted hazard ratio for mortality in the pre-CSWG era was 1.22 (p = 0.015) for the historical cohort and 1.20 (p = 0.047) for the contemporary cohort. CS-international collaboration enhanced outcomes through standardized protocols, advanced interventions, and dedicated CS teams, underscoring the importance of international cooperation in CS care.
3. Unlocking prognostic insights in severe tricuspid regurgitation: impact of right ventricular volumes and function by cardiac magnetic resonance.
In a multicenter cohort of 314 severe TR patients, CMR-derived RV-EDV and RVEF independently predicted all-cause death/HF hospitalization. High-risk thresholds were RV-EDV >150 mL/m2 and RVEF <50%, with adjusted HRs up to 5.42 for RV-EDV, enabling pragmatic risk stratification.
Impact: Defines actionable RV volumetric and functional thresholds that can guide timing for TR intervention and follow-up strategies in an area with unmet prognostic tools.
Clinical Implications: CMR should be considered to quantify RV-EDV and RVEF in severe TR; patients with RV-EDV >150 mL/m2 or RVEF <50% may warrant expedited evaluation for transcatheter or surgical intervention.
Key Findings
- RV-EDV and RVEF independently predict all-cause mortality and HF hospitalization in severe TR (adj HR per mL/m2 for RV-EDV 1.015; per % for RVEF 0.957).
- High-risk thresholds identified: RV-EDV >150 mL/m2 (adj HR 5.42) and RVEF <50% (adj HR 2.12); intermediate risk: RV-EDV 100–150 mL/m2 and RVEF 50–60%.
- Thirty-nine percent experienced the composite endpoint over a median 35-month follow-up.
Methodological Strengths
- Multicenter cohort with contemporary CMR across severe TR phenotypes.
- Rigorous multivariable adjustment defining clinically interpretable thresholds.
Limitations
- Observational design precludes causal inference about intervention timing.
- CMR availability and standardization may limit generalizability in some settings.
Future Directions: Prospective studies to test whether CMR-guided thresholds improve timing of TR intervention and outcomes; integration with right-heart hemodynamics and RV-PA coupling metrics.
AIMS: To describe prognostic cut-off values of right ventricular (RV) size and function by cardiac magnetic resonance (CMR) in a multicentre cohort of patients with severe tricuspid regurgitation (TR). METHODS AND RESULTS: The study enrolled patients with at least severe TR (severe, massive, and torrential) assessed by 2D echocardiography undergoing a contemporary CMR study. The primary endpoint was defined as combined endpoint of all-cause mortality or hospitalization for heart failure (HF) events, and the secondary endpoint was defined as cardiovascular mortality. Three hundred fourteen patients with severe TR were included in this study (70 ± 11 years, 67% female, 79% NYHA I or II). During a median follow-up of 35 months (interquartile range: 12-60), 39% of the patients experienced the combined endpoint. After adjusting for clinical and imaging variables, RV end-diastolic volume (RV-EDV) and RV ejection fraction (RVEF) were independently associated with all-cause mortality and HF (adj HR for RV-EDV: 1.015 [1.012-1.019], P < 0.001; adj HR for RVEF: 0.957 [0.938-0.976], P < 0.001). Thresholds of highest risk were defined by RV-EDV > 150 mL/m² and RVEF < 50%, while intermediate risk was defined by RV-EDV between 100 and 150 mL/m² and RVEF between 50% and 60%. Compared with low-risk groups, adjusted threshold for high-risk (adj HR for RV-EDV > 150 mL/m2: 5.42 [3.20-9.16] and for RVEF < 50%: 2.12 [1.21-3.71]) and intermediate-risk (adj HR for RV-EDV 100-150 mL/m2: 1.72 [1.11-2.64] and for RVEF 50-60%: 1.59 [1.04-2.43]) was significantly associated with impaired outcomes. CONCLUSION: Thresholds of RV volume and function by CMR stratifying low-intermediate and high-risk of cardiovascular events are defined in a multicentre cohort of patients. Compared with low-risk group, high- and, to a lower extent, intermediate-risk groups are independently associated to HF and all-cause mortality.