Daily Cardiology Research Analysis
Three impactful cardiology studies stood out today: a multicenter JAMA RCT found that levosimendan did not facilitate weaning from VA-ECMO in severe cardiogenic shock and increased ventricular arrhythmias; an international JACC Cardiovascular Imaging registry showed AI-guided quantitative coronary CTA adds prognostic value beyond CAD-RADS and calcium scores; and a PLoS Genetics GWAS-meta analysis identified genetic regulators of urinary zinc, linking zinc handling to cardiometabolic risk and str
Summary
Three impactful cardiology studies stood out today: a multicenter JAMA RCT found that levosimendan did not facilitate weaning from VA-ECMO in severe cardiogenic shock and increased ventricular arrhythmias; an international JACC Cardiovascular Imaging registry showed AI-guided quantitative coronary CTA adds prognostic value beyond CAD-RADS and calcium scores; and a PLoS Genetics GWAS-meta analysis identified genetic regulators of urinary zinc, linking zinc handling to cardiometabolic risk and stroke via Mendelian randomization and in vivo validation.
Research Themes
- Critical care cardiology and ECMO pharmacotherapy
- AI-driven coronary imaging risk stratification
- Nutritional genetics and cardiometabolic disease mechanisms
Selected Articles
1. Genetic determinants of zinc homeostasis and its role in cardiometabolic diseases.
This first GWAS-meta analysis of urinary zinc identifies 11 loci, with a lead SLC30A2 variant explaining 6.1% of variance and colocalizing with kidney tubular expression. Urinary zinc is genetically distinct from plasma zinc and associates with adverse cardiometabolic profiles; Mendelian randomization suggests diabetes increases urinary zinc and higher urinary zinc causally increases stroke risk. Cross-population analyses and mouse experiments support a kidney zinc transporter axis and highlight urinary zinc as a non-invasive biomarker.
Impact: Provides novel mechanistic and population-level insights into zinc homeostasis linking kidney transporters to cardiometabolic disease and stroke risk, integrating GWAS, MR, and animal validation.
Clinical Implications: Urinary zinc could serve as a noninvasive biomarker for cardiometabolic and stroke risk stratification, especially in diabetes. Population differences in genetic zinc excretion highlight the need for tailored nutrition and public health strategies.
Key Findings
- Identified 11 genome-wide significant loci for urinary zinc, with SLC30A2 rs3008217 explaining 6.1% of variance and colocalizing with kidney tubular expression.
- Urinary and plasma zinc show low phenotypic and genetic correlation, indicating distinct regulation.
- Mendelian randomization suggested diabetes causally increases urinary zinc, and elevated urinary zinc increases stroke risk.
- Cross-population analysis showed ~3-fold higher genetic risk of zinc excretion in sub-Saharan Africa correlating with nutritional deficiency prevalence.
- Dietary zinc deficiency in mice decreased urinary, but not plasma, zinc and upregulated renal Slc30a2.
Methodological Strengths
- Multicohort GWAS meta-analysis with colocalization and Mendelian randomization.
- Cross-validation with in vivo mouse experiments and population allele frequency analyses.
Limitations
- Primary discovery cohorts were European-ancestry; external validity to diverse ancestries requires further study.
- MR assumptions may be violated by pleiotropy; causal estimates rely on instrument validity.
- Limited sample for human milk SLC30A2 variant analyses (n=387 mothers).
Future Directions: Validate urinary zinc as a prospective biomarker across ancestries; dissect transporter-specific mechanisms in kidney; test whether nutritional or pharmacologic modulation of zinc handling alters cardiometabolic and stroke risk.
Zinc is essential for many physiological processes and its deficiency is highly prevalent worldwide. Its complex homeostasis involves membrane transporters from the SLC39/ZIP and SLC30/ZnT protein families. We conducted a genome-wide association study (GWAS) meta-analysis of urinary zinc levels in three European-ancestry cohorts (N = 10,113), followed by in silico and in vivo studies to elucidate their underlying public health and physiological relevance. We identified eleven genome-wide significant signals with six mapping to SLC39/ZIP and SLC30/ZnT gene regions. The lead signal (rs3008217C>G, p = 2.42E-110) in the SLC30A2 gene region which explained 6.1% of urinary zinc variation strongly colocalized with its expression in kidney tubules. Low phenotypic and genetic correlations between plasma and urinary zinc levels indicated distinct genetic regulation. High urinary zinc correlated with an unfavorable cardiometabolic profile, and Mendelian randomization analyses suggested causal roles for diabetes increasing urinary zinc levels, and elevated urinary zinc increasing stroke risk. Analyzing country-level allele frequencies and zinc deficiency prevalences revealed a 3-fold higher genetic zinc excretion risk in sub-Saharan Africa compared to Europe, significantly correlating with nutritional zinc deficiency prevalence. Although mutations in SLC30A2 are linked to insufficient zinc in human milk, we found no association with common variants using data generated from 387 mothers. Mice experiments showed that dietary zinc deficiency decreased urinary but not plasma zinc levels, and upregulated kidney Slc30a2 expression. This first GWAS on urinary zinc highlights the involvement of zinc transporters in its genetic regulation, as well as its role as a non-invasive biomarker for cardiometabolic diseases.
2. Levosimendan to Facilitate Weaning From ECMO in Patients With Severe Cardiogenic Shock: The LEVOECMO Randomized Clinical Trial.
In 205 VA-ECMO patients with severe cardiogenic shock, levosimendan did not reduce time to successful ECMO weaning at 30 days compared with placebo (68.3% vs 68.3%; SHR 1.02). No significant differences were observed in ECMO duration, ICU stay, or 60-day mortality, while ventricular arrhythmias were more frequent with levosimendan (17.8% vs 8.7%).
Impact: A rigorous, multicenter, double-blind RCT addressing a common off-label practice provides definitive evidence against routine levosimendan use for ECMO weaning and highlights safety concerns.
Clinical Implications: Levosimendan should not be routinely used to facilitate VA-ECMO weaning in severe cardiogenic shock. Clinicians should monitor for ventricular arrhythmias when considering inodilators and prioritize evidence-based weaning strategies.
Key Findings
- No difference in successful ECMO weaning within 30 days: 68.3% levosimendan vs 68.3% placebo; SHR 1.02 (95% CI 0.74-1.39).
- No significant differences in ECMO duration (median 5 vs 6 days), ICU length of stay (18 vs 19 days), or 60-day mortality (27.7% vs 25.0%).
- Ventricular arrhythmias were more frequent with levosimendan (17.8% vs 8.7%; absolute risk difference 9.2%).
Methodological Strengths
- Randomized, double-blind, placebo-controlled, multicenter design with prespecified outcomes.
- High protocol adherence with dose escalation and robust clinical endpoints including competing risk analysis.
Limitations
- Not powered for mortality differences; heterogeneity of shock etiologies (postcardiotomy, AMI, myocarditis).
- Trial limited to French ICUs; generalizability to other settings and ECMO practices may vary.
Future Directions: Identify subgroups that might benefit from inodilators; evaluate alternative pharmacologic or protocolized weaning strategies; integrate electrophysiology monitoring to mitigate arrhythmia risk.
IMPORTANCE: Levosimendan may facilitate weaning from venoarterial extracorporeal membrane oxygenation (VA-ECMO) and improve survival, but supporting evidence remains limited. OBJECTIVE: To assess whether early administration of levosimendan reduces the time to successful VA-ECMO weaning in patients with severe but potentially reversible cardiogenic shock. DESIGN, SETTING, AND PARTICIPANTS: Randomized, double-blind, placebo-controlled trial conducted across 11 intensive care units (ICUs) in France. Between August 27, 2021, and September 10, 2024, 205 adult patients with acute cardiogenic shock who had started VA-ECMO in the preceding 48 hours were enrolled. Final follow-up was completed on November 10, 2024. INTERVENTIONS: Patients were randomized in a 1:1 ratio to receive levosimendan, 0.15 μg/kg per minute, to be increased to 0.20 μg/kg per minute after 2 hours (n = 101), or placebo (n = 104). MAIN OUTCOMES AND MEASURES: The primary outcome was time to successful ECMO weaning within 30 days following randomization. Secondary outcomes included ECMO-, mechanical ventilation-, and organ failure-free days, ICU and hospital lengths of stay, serious adverse events, and all-cause 30- and 60-day mortality.
3. Prognostic Value of AI-Based Quantitative Coronary CTA vs Human Reader-Based Visual Assessment: Results From the CONFIRM2 Registry.
In 1,916 patients with 3-year follow-up, AI-QCT (combining noncalcified plaque burden and diameter stenosis) significantly improved risk discrimination and reclassification for MACE compared with CAD-RADS, CACS, the modified Duke Index, and CAD-RADS+CACS. In patients without severe stenosis (≥70%), AI-QCT remained independently associated with MACE and death/MI, outperforming CAD-RADS.
Impact: Demonstrates that AI-driven quantitative plaque metrics provide incremental prognostic value beyond standard visual reads and calcium scoring, supporting integration of AI-QCT into clinical workflows.
Clinical Implications: AI-QCT can refine risk stratification after coronary CTA, particularly in patients without severe stenosis, potentially guiding preventive therapies and follow-up intensity beyond CAD-RADS/CACS alone.
Key Findings
- AI-QCT improved AUC for MACE vs CAD-RADS (0.81 vs 0.79; P<0.001; NRI 0.47) and vs CACS (0.79 vs 0.70; P<0.001; NRI 0.61).
- Incremental prognostic value persisted after adjusting for clinical likelihood and for death/MI endpoint.
- Excluding ≥70% stenosis, AI-QCT remained significant whereas CAD-RADS was not, with better AUC for both MACE (0.77 vs 0.72) and death/MI (0.81 vs 0.73).
Methodological Strengths
- International multicenter cohort with standardized AI quantification and core methodology.
- Robust statistical comparisons including AUC, continuous NRI, and multivariable adjustment with sensitivity analyses.
Limitations
- Observational design limits causal inference; residual confounding possible.
- AI-QCT pipeline and performance may be vendor/algorithm-specific; external generalizability needs further validation.
- Event rate was modest (4.5% MACE), which may affect precision of subgroup estimates.
Future Directions: Prospective trials to assess AI-QCT–guided management; head-to-head comparisons across AI vendors; integration with clinical and biomarker models for precision prevention.
BACKGROUND: The severity and extent of whole heart coronary plaque volume and stenosis can be reliably measured by artificial intelligence-guided quantitative coronary computed tomography angiography (AI-QCT). Limited data are available on the potential incremental prognostic value compared with currently recommended qualitative coronary computed tomography angiography (CTA) reads and the coronary artery calcium score (CACS). OBJECTIVES: The aim of this study was to evaluate the prognostic value of AI-QCT compared with human coronary CTA reads, including the CAD-RADS (Coronary Artery Disease-Reporting and Data System), CACS, and the modified Duke Index. METHODS: CONFIRM2 (Quantitative COroNary CT Angiography Evaluation For Evaluation of Clinical Outcomes: An InteRnational, Multicenter Registry) is a multicenter, international, observational cohort study of patients undergoing clinically indicated coronary CTA with follow-up for major adverse cardiac events (MACE).