Daily Cardiology Research Analysis
Three high-impact studies span cardio-oncology mechanisms, heart failure therapy in neglected populations, and acute thrombolysis for prosthetic valve thrombosis. A mechanistic study reveals a reversible osimertinib cardiomyopathy via the GATA4–MYLK3–MYL2 axis with prevention by omecamtiv, a large RCT evaluates sacubitril/valsartan versus enalapril in Chagas cardiomyopathy, and a randomized trial shows tenecteplase outperforms alteplase for mechanical prosthetic valve thrombosis.
Summary
Three high-impact studies span cardio-oncology mechanisms, heart failure therapy in neglected populations, and acute thrombolysis for prosthetic valve thrombosis. A mechanistic study reveals a reversible osimertinib cardiomyopathy via the GATA4–MYLK3–MYL2 axis with prevention by omecamtiv, a large RCT evaluates sacubitril/valsartan versus enalapril in Chagas cardiomyopathy, and a randomized trial shows tenecteplase outperforms alteplase for mechanical prosthetic valve thrombosis.
Research Themes
- Cardio-oncology mechanisms and mitigation of TKI cardiotoxicity
- Heart failure therapeutics in neglected tropical disease (Chagas cardiomyopathy)
- Thrombolysis optimization for mechanical prosthetic valve thrombosis
Selected Articles
1. Osimertinib induces reversible cardiac dysfunction through the GATA4-MYLK3-MYL2 axis.
Using iPSC-cardiomyocytes and a stress-augmented mouse model, the authors show that osimertinib triggers reversible sarcomeric dysfunction via GATA4 dephosphorylation, MYLK3 suppression, and reduced MYL2 phosphorylation. Pharmacologic activation of myosin with omecamtiv prevented dysfunction, suggesting a targeted mitigation strategy for TKI cardiotoxicity.
Impact: This study uncovers a specific, druggable pathway of TKI cardiotoxicity and demonstrates a feasible rescue with a clinically relevant myosin activator. It advances cardio-oncology by linking molecular mechanism to a potential therapeutic countermeasure.
Clinical Implications: For patients on osimertinib who develop LV dysfunction, cardiotoxicity may be reversible with drug interruption and potentially preventable with myosin activation. Mechanistic biomarkers (MYLK3/MYL2 signaling) could inform surveillance strategies.
Key Findings
- Osimertinib caused contractile dysfunction without cell death, inflammation, or fibrosis in a TAC-augmented mouse model.
- Single-nucleus RNA-seq and in vitro assays identified MYLK3 downregulation and reduced MYL2 phosphorylation with sarcomere disarray as central mechanisms.
- GATA4 dephosphorylation linked osimertinib exposure to MYLK3 transcriptional suppression.
- Cardiac dysfunction was reversible upon drug discontinuation.
- The myosin activator omecamtiv prevented osimertinib-induced dysfunction.
Methodological Strengths
- Multi-system validation combining iPSC-derived cardiomyocytes with an in vivo mouse hemodynamic-stress model
- Single-nucleus RNA sequencing to delineate cell-specific transcriptional programs and mechanistic targets
Limitations
- Preclinical study without prospective human validation of the mitigation strategy
- Model (TAC plus osimertinib) may not capture full clinical heterogeneity of patients
Future Directions: Translate findings into early-phase clinical studies testing myosin activation to prevent or reverse TKI cardiotoxicity; validate circulating or imaging biomarkers reflecting the GATA4–MYLK3–MYL2 axis.
BACKGROUND AND AIMS: Osimertinib is a third-generation tyrosine kinase inhibitor targeting activating mutations of epidermal growth factor receptor with remarkable therapeutic efficacy against non-small cell lung carcinoma. However, its use has been limited by associated cardiotoxicity, primarily with heart failure. Herein, this study aims to better understand the mechanisms underlying osimertinib cardiotoxicity and explore cardioprotective strategies. METHODS: This study leverages an in vitro model of human induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) and a clinically relevant in vivo mouse model of osimertinib cardiotoxicity by co-employing transverse aortic constriction to mimic haemodynamic stress in cancer patients. RESULTS: Osimertinib treatment leads to significant contractile dysfunction in mice without cell death, inflammation, or fibrosis. By leveraging single-nucleus RNA sequencing of mouse heart tissues and in vitro assays of human iPSC-CMs, the study reveals significant downregulation of MYLK3 and a subsequent decrease in MYL2 phosphorylation with marked sarcomere disarray as the main mechanism of osimertinib cardiotoxicity. GATA4 is further identified as a putative target of osimertinib, connecting its decreased phosphorylation to repressed MYLK3 transcription. The reversibility of osimertinib-induced cardiac dysfunction upon discontinuation of osimertinib treatment supports the hypothesis that transient sarcomere disruption, rather than permanent cellular damage, serves as the key underlying mechanism. Finally, the myosin activator omecamtiv is shown to be effective in preventing osimertinib cardiotoxicity. CONCLUSIONS: These findings suggest that osimertinib causes reversible cardiac dysfunction by disrupting MYL2 phosphorylation via GATA4 dephosphorylation-mediated suppression of MYLK3 and highlight the potential of myosin activation as a preventive or rescue strategy for osimertinib cardiotoxicity.
2. Sacubitril/Valsartan vs Enalapril in Heart Failure Due to Chagas Disease: An Open-Label, Multicenter Randomized Clinical Trial.
In 922 patients with HFrEF due to Chagas disease, sacubitril/valsartan did not reduce cardiovascular death or first HF hospitalization versus enalapril over a median 25.2 months. However, sacubitril/valsartan achieved a significantly greater 12-week reduction in NT-proBNP, yielding a win ratio of 1.52.
Impact: This is the largest RCT addressing guideline therapy specifically in Chagas cardiomyopathy, a neglected condition with high mortality in Latin America. It informs disease-specific expectations for ARNI therapy beyond extrapolation from non-Chagas HFrEF.
Clinical Implications: For Chagas HFrEF, ARNI may be considered for biomarker reduction, but current evidence does not show superiority in hard outcomes over enalapril; guideline adoption should be cautious and context-specific.
Key Findings
- 922 randomized patients across 83 sites; median follow-up 25.2 months.
- No significant difference in cardiovascular death (23.8% vs 25.4%) or first HF hospitalization (22.1% vs 24.1%).
- Greater 12-week NT-proBNP reduction with sacubitril/valsartan (30.6% decrease) vs enalapril (5.5% decrease), yielding a stratified win ratio 1.52 (95% CI 1.28-1.82; P<.001).
Methodological Strengths
- Large, multicenter randomized design with prespecified hierarchical composite and win-ratio analysis
- Enrollment across endemic regions with confirmed Chagas diagnosis increases external validity
Limitations
- Open-label design may introduce performance bias
- Primary hierarchy influenced by biomarker change; lack of superiority in clinical outcomes
Future Directions: Identify Chagas subgroups (e.g., inflammatory or arrhythmic phenotypes) most likely to benefit from ARNI; test combination strategies and longer-term outcome effects; integrate mechanistic biomarkers.
IMPORTANCE: The efficacy and safety of guideline-recommended treatments for heart failure (HF) are uncertain in patients with Chagas disease. OBJECTIVE: To evaluate the efficacy and safety of the angiotensin receptor-neprilysin inhibitor sacubitril/valsartan in patients with HF with reduced ejection fraction due to Chagas disease. DESIGN, SETTING, AND PARTICIPANTS: From December 10, 2019, through September 13, 2023, patients with HF, confirmed diagnosis of Chagas disease, left ventricular ejection fraction of 40% or less, and N-terminal pro-B-type natriuretic peptide (NT-proBNP) of 600 pg/mL or greater (or B-type natriuretic peptide [BNP] ≥150 pg/mL) or 400 pg/mL or greater (or BNP ≥100 pg/mL) if hospitalized for HF within the previous 12 months were screened at 83 sites in Argentina, Brazil, Colombia, and Mexico. Statistical analysis was conducted between May and July 2025. INTERVENTIONS: Patients were randomized to receive sacubitril/valsartan (target dose, 200 mg twice daily) or enalapril (target dose, 10 mg twice daily), in addition to standard therapy. MAIN OUTCOMES AND MEASURES: The primary end point was a hierarchical composite outcome tested, in order, of death from cardiovascular causes, hospitalization for HF, or relative change in NT-proBNP from baseline to 12 weeks. The primary analysis was done using a win ratio approach. RESULTS: Overall, 462 participants were randomized to receive sacubitril/valsartan and 460 to receive enalapril (mean [SD] age, 64.2 [10.8] years; 387 [42.0%] were female). Over a median (IQR) follow-up of 25.2 (18.4-33.2) months, cardiovascular death occurred in 110 patients (23.8% [18.3% wins in the hierarchical comparison]) in the sacubitril/valsartan group and 117 patients (25.4% [17.5% wins]) in the enalapril group. A total of 102 patients (22.1% [7.7% wins]) in the sacubitril/valsartan group and 111 (24.1% [6.9% wins]) in the enalapril group experienced a first hospitalization for HF. Patients in the sacubitril/valsartan group had a median (IQR) decrease in NT-proBNP of 30.6% (-54.3% to -0.9%) at 12 weeks, leading to 22.5% wins, while those in the enalapril group had a 5.5% (-31.9% to 37.5%) decrease (7.2% wins). The resulting stratified win ratio was 1.52 (95% CI, 1.28-1.82; P < .001) for sacubitril/valsartan compared with enalapril. CONCLUSIONS AND RELEVANCE: In patients with HF with reduced ejection fraction due to Chagas disease, there was no significant difference in clinical outcomes between sacubitril/valsartan and enalapril, but there was a greater reduction in NT-proBNP at 12 weeks in patients in the sacubitril/valsartan group.
3. Tenecteplase vs Alteplase in Mechanical Prosthetic Heart Valve Thrombosis: The TENET Randomized Clinical Trial.
In 83 patients with obstructive mechanical prosthetic valve thrombosis, tenecteplase achieved higher complete thrombolytic success (97.5% vs 81.5%) and shorter hospital stay (median 4.1 vs 6.5 days) than alteplase, with similar adverse event rates.
Impact: This is the first randomized comparison in mechanical valve thrombosis, suggesting a simpler bolus regimen (tenecteplase) may improve efficacy and efficiency over standard alteplase infusions.
Clinical Implications: Tenecteplase can be considered a front-line thrombolytic for obstructive mechanical valve thrombosis, potentially reducing hospital LOS and streamlining care, especially where infusion infrastructure is limited.
Key Findings
- Complete thrombolytic success: 97.5% with tenecteplase vs 81.5% with alteplase (RR 1.18; 95% CI 1.03–1.39; P=.02 for noninferiority).
- Shorter hospital stay with tenecteplase (median 4.1 vs 6.5 days; P<.001).
- Similar rates of major and minor adverse events between groups.
Methodological Strengths
- Randomized non-inferiority design directly comparing two thrombolytic strategies
- Clinically meaningful endpoints including complete thrombolysis and length of stay
Limitations
- Single-center, open-label trial with modest sample size
- Short-term outcomes; no long-term follow-up on valve function or recurrence
Future Directions: Multicenter trials to confirm efficacy and safety, define optimal dosing in diverse valve positions, and assess long-term outcomes and cost-effectiveness.
IMPORTANCE: For patients presenting with symptomatic prosthetic valve thrombosis (PVT) after mechanical heart valve replacement, thrombolytic therapy with alteplase is accepted as a first-line therapeutic alternative. The utility of tenecteplase compared with conventional regimens remains unstudied, to the authors' knowledge, in this patient population. OBJECTIVE: To assess the relative safety and efficacy of tenecteplase compared with standard infusions of alteplase in patients with PVT. DESIGN, SETTING AND PARTICIPANTS: This was an open-label, parallel-group, non-inferiority randomized clinical trial among consecutive adult patients presenting with obstructive PVT of a mechanical prosthetic valve over the study period from October 2022 to August 2024 to a single tertiary care center in India. INTERVENTIONS: Patients received thrombolytic therapy with a low-dose slow infusion alteplase or weight-based bolus doses of tenecteplase. MAIN OUTCOMES AND MEASURES: The primary outcomes were to determine the rates of complete thrombolytic success and the incidence of major complications. RESULTS: A total of 83 patients (mean [SD] age, 39.6 [12.4] years, 42 male [50.6%]) were randomized to receive alteplase (n = 43) or tenecteplase (n = 40). The rates of the primary efficacy end point (complete thrombolytic success) were significantly higher (risk ratio, 1.18; 95% CI, 1.03-1.39; P = .02 for noninferiority) in the tenecteplase group (39 patients [97.5%]) compared with the alteplase group (35 patients [81.5%]). Additionally, patients treated with tenecteplase had higher rates of complete success with the first administered dose and a shorter duration of hospital stay (median [IQR], 4.1 [3.2-5.1] days vs 6.5 [4.3-9.2] days; P < .001). The rates of major and minor adverse events were similar. CONCLUSIONS AND RELEVANCE: Tenecteplase may be a safe and effective alternative to alteplase in patients presenting with obstructive PVT. Patients treated with tenecteplase in our study had higher rates of complete thrombolytic success and a shorter duration of hospital stay. Furthermore, the relative ease of drug administration with tenecteplase may translate to greater clinical benefit in a real-world setting. TRIAL REGISTRATION: Clinical Trials Registry of India: CTRI/2022/10/046127.