Evaluation of Left Atrial Electromechanical Delay and Left Atrial Phasic Functions in Patients Undergoing Treatment with Cardiotoxic Chemotherapeutic Agents.

Background: The aim of this study is to evaluate atrial involvement by comparing pre- and post-chemotherapy left atrial mechanical and electromechanical parameters in patients treated with cardiotoxic chemotherapeutic agents. Methods: We designed our study as a prospective cohort study. Sixty-eight female patients between the ages of 18 and 50, scheduled for treatment with cardiotoxic chemotherapeutic agents, were included in our study. Atrial mechanical functions and electromechanical parameters were examined and compared with basic echocardiographic parameters before and after chemotherapy. Results: The mean age of the patients was 41.6 ± 7.9 years. After chemotherapy, lateral PA, septal PA, and tricuspid PA durations showed a significant increase (p < 0.001), but there were no statistically significant changes in the left intra-atrial electromechanical delay, the right intra-atrial electromechanical delay, or the interatrial electromechanical delay values. Following treatment, LAVmax, LAVmin, and LApreA significantly increased (p < 0.001). Additionally, the left atrial passive and active emptying volumes increased (p < 0.001), while the reservoir and pump (active emptying) functions decreased (with p-values of 0.03 and 0.01, respectively). The passive emptying function, however, showed no significant change (p = 0.65). Decreases in LVEF were observed, while LVEDD, LVESD, IVS, PW, and LA diameters increased (p-value of 0.02 for IVS and <0.001 for the others). Conclusions: Significant impairment of atrial mechanical functions and electromechanical parameters was observed after treatment with cardiotoxic chemotherapeutic agents. This suggests an elevated likelihood of atrial arrhythmia linked to the use of cardiotoxic chemotherapeutic agents.

Efficacy of mitral annular velocity as an alternative marker of left ventricular global longitudinal strain to detect the risk of cancer therapy-related cardiac disorders.

PURPOSE: Left ventricular longitudinal function can be rapidly evaluated by measuring S' and mitral annular plane systolic excursion (MAPSE) using tissue Doppler imaging. Even when the image quality is poor and the left ventricular endocardium is not visible, S' and MAPSE can be measured if the mitral annulus is visible. However, the utility of S' and MAPSE in diagnosing cancer therapy-related cardiac dysfunction (CTRCD) remains unclear. This study aimed to examine the diagnostic performance of S' and MAPSE and determine appropriate cutoff values. METHODS: We retrospectively enrolled 279 breast cancer patients who underwent pre- or postoperative chemotherapy with anthracyclines and trastuzumab from April 2020 to November 2022. We compared echocardiographic data before chemotherapy, 6 months after chemotherapy initiation, and 1 year later. CTRCD was defined as a decrease in left ventricular ejection fraction below 50%, with a decrease of ≥10% from baseline or a relative decrease in left ventricular global longitudinal strain (LVGLS) of ≥15%. RESULTS: A total of 256 participants were included in this study, with a mean age of 50.2 ± 11 years. Fifty-six individuals (22%) developed CTRCD within 1 year after starting chemotherapy. The cutoff value for septal S' was 6.85 cm/s (AUC = .81, p < .001; sensitivity 74%; specificity 73%), and for MAPSE was 11.7 mm (AUC = .65, p = .02; sensitivity 79%; specificity 45%). None of the cases with septal S' exceeding 6.85 cm/s had an LVGLS of ≤15%. CONCLUSIONS: Septal S' is a useful indicator for diagnosing CTRCD. HIGHLIGHTS: Septal S' decreased at the same time or earlier than the decrease in LVGLS. The septal S' demonstrated higher diagnostic ability for CTRCD compared to LVGLS.

Assessment of cancer therapy-related cardiac dysfunction in breast cancer women using a new speckle tracking echocardiography index: The GAVS.

BACKGROUND: Recently, peak atrial longitudinal strain (PALS) has emerged as a possible predictor of Cancer therapy-related cardiac dysfunction (CTRCD) in cancer patients (CP), in addition to left ventricular global longitudinal strain (GLS). Thus, considering the link between left atrium and left ventricle, the aim of this study was to assess the global atrio-ventricular strain (GAVS) in CP, to detect early cardiotoxicity. METHODS: A prospective study was carried out enrolling 131 breast cancer women (mean age 51.4 ± 10.4 years) receiving anti-cancer treatment. Clinical and echocardiographic evaluation was performed at baseline (T0), 3 (T1), 6 (T2) and 12 months (T3) after starting treatment. CTRCD was defined according to the 2022 ESC Cardio-Oncology guidelines. RESULTS: Forty-four patients developed CTRCD (3 moderate and 41 mild CTRCD group A) and 87 patients did not (group B). In group A, significant changes in GLS, PALS, GAVS, LASi (left atrial stiffness index) and LVEF/GLS occurred earlier than LVEF, that reduced significantly only at T3 (p-value < .05). Significant changes in LASi, PALS and GAVS occurred even in group B but reduction in GAVS (-21% vs. -5%) and PALS (-24% vs. -12%) was significantly greater in group A compared to group B (p-value = .04). CONCLUSIONS: Our study confirms high sensitivity of speckle tracking echocardiography in detecting subclinical myocardial damage in CP and the usefulness of a multiparametric echocardiographic evaluation including PALS and GLS (GAVS) for having a global evaluation of the phenomenon cardiotoxicity.

Exercise-based cardio-oncology rehabilitation for cardiotoxicity prevention during breast cancer chemotherapy: The ONCORE randomized controlled trial.

BACKGROUND: Breast cancer (BC) treatment with anthracyclines and/or anti-human epidermal growth factor receptor-2 (HER2) antibodies is associated with an increased risk of cardiovascular disease complications, including cancer therapy-related cardiac dysfunction (CTRCD). While Cardio-Oncology Rehabilitation (CORe) programs including exercise have emerged to minimize these risks, its role in preventing CTRCD is unclear. OBJECTIVES: We investigated the effectiveness of an exercise-based CORe program in preventing CTRCD [left ventricular ejection fraction (LVEF) drop ≥10% to a value <53% or a decrease >15% in global longitudinal strain (GLS)]. Secondary outcomes examined changes in cardiac biomarkers, physical performance including peak oxygen consumption, psychometric and lifestyle outcomes. Safety, adherence, and patient satisfaction were also assessed. METHODS: This is a randomized controlled trial including 122 early-stage BC women receiving anthracyclines and/or anti-HER2 antibodies, randomized to CORe (n = 60) or usual care with exercise recommendation (n = 62). Comprehensive assessments were performed at baseline and after cardiotoxic treatment completion. The average duration of the intervention was 5.8 months. RESULTS: No cases of CTRCD were identified during the study. LVEF decreased in both groups, but was significantly attenuated in the CORe group [-1.5% (-2.9, -0.1); p = 0.006], with no changes detected in GLS or cardiac biomarkers. The CORe intervention led to significant body mass index (BMI) reduction (p = 0.037), especially in obese patients [3.1 kg/m2 (1.3, 4.8)]. Physical performance and quality-of-life remained stable, while physical activity level increased in both groups. No adverse events were detected. CONCLUSIONS: This study suggests that CORe programs are safe and may help attenuate LVEF decline in BC women receiving cardiotoxic therapy and reduce BMI in obese patients.

Arsenic trioxide-induced cardiotoxicity triggers ferroptosis in cardiomyoblast cells.

Arsenic trioxide (ATO) has been found to be effective in acute promyelocytic leukemia. However, ATO-induced severe cardiotoxicity limits its clinical application. To date, the mechanisms of ATO-induced cardiotoxicity remain unclear. It is hypothesized that ferroptosis may trigger ATO-induced cardiotoxicity; however, this has not yet been investigated. To clarify this hypothesis, rat cardiomyocyte H9c2 cells were treated with ATO with or without ferrostain-1 (Fer-1). The results indicated that ATO exposure induced H9c2 cell death and apoptosis, and the ferroptosis inhibitor Fer-1, administered for 24 h before ATO exposure, suppressed ATO-induced cell death, and apoptosis, as determined by Annexin V-APC/7-AAD apoptosis assay. Furthermore, Fer-1 displayed a cardioprotective effect through inhibiting the ATO-induced production of intracellular reactive oxygen species, improving the ATO-induced loss of the mitochondrial membrane potential, alleviating hyperactive endoplasmic reticulum stress, and alleviating the ATO-induced impairment in autophagy in H9c2 cells. Overall, the cardioprotective effect of Fer-1 against ATO-induced cell injury implies that ATO may trigger ferroptosis to induce cardiotoxicity. These findings lay the foundation for exploring the potential value of ferroptosis inhibitors against ATO-induced cardiotoxicity in the future.

Cardiotoxicity of cyclophosphamide's metabolites: an in vitro metabolomics approach in AC16 human cardiomyocytes.

Cyclophosphamide is a widely used anticancer and immunosuppressive prodrug that unfortunately causes severe adverse effects, including cardiotoxicity. Although the exact cardiotoxic mechanisms are not completely understood, a link between cyclophosphamide's pharmacologically active metabolites, namely 4-hydroxycyclophosphamide and acrolein, and the toxicity observed after the administration of high doses of the prodrug is likely. Therefore, the objective of this study is to shed light on the cardiotoxic mechanisms of cyclophosphamide and its main biotransformation products, through classic and metabolomics studies. Human cardiac proliferative and differentiated AC16 cells were exposed to several concentrations of the three compounds, determining their basic cytotoxic profile and preparing the next study, using subtoxic and toxic concentrations for morphological and biochemical studies. Finally, metabolomics studies were applied to cardiac cells exposed to subtoxic concentrations of the aforementioned compounds to determine early markers of damage. The cytotoxicity, morphological and biochemical assays showed that 4-hydroxycyclophosphamide and acrolein induced marked cardiotoxicity at µM concentrations (lower than 5 µM), being significantly lower than the ones observed for cyclophosphamide (higher than 2500 µM). Acrolein led to increased levels of ATP and total glutathione on proliferative cells at 25 µM, while no meaningful changes were observed in differentiated cells. Higher levels of carbohydrates and decreased levels of fatty acids and monoacylglycerols indicated a metabolic cardiac shift after exposure to cyclophosphamide's metabolites, as well as a compromise of precursor amino acids used in the synthesis of glutathione, seen in proliferative cells' metabolome. Overall, differences in cytotoxic mechanisms were observed for the two different cellular states used and for the three molecules, which should be taken into consideration in the study of cyclophosphamide cardiotoxic mechanisms.

Contribution of membrane transporters to chemotherapy-induced cardiotoxicity.

Membrane transporters play a key role in determining the pharmacokinetic profile, therapeutic safety, and efficacy of many chemotherapeutic drugs by regulating cellular influx and efflux. Rapidly emerging evidence has shown that tissue-specific expression of transporters contributes to local drug accumulation and drug-drug interactions and that functional alterations in these transporters can directly influence an individual's susceptibility to drug-induced toxicity. Comprehending the complex mechanism of transporter function in regulating drug distribution in tissues, such as the heart, is necessary in order to acquire novel therapeutic strategies aimed at evading unwanted drug accumulation and toxicities and to ameliorate the safety of current therapeutic regimens. Here, we provide an overview of membrane transporters with a role in chemotherapy-induced cardiotoxicity and discuss novel strategies to improve therapeutic outcomes.

Identification of Drug Transporter Genomic Variants and Inhibitors That Protect Against Doxorubicin-Induced Cardiotoxicity.

BACKGROUND: Multiple pharmacogenomic studies have identified the synonymous genomic variant rs7853758 (G > A, L461L) and the intronic variant rs885004 in SLC28A3 (solute carrier family 28 member 3) as statistically associated with a lower incidence of anthracycline-induced cardiotoxicity. However, the true causal variant(s), the cardioprotective mechanism of this locus, the role of SLC28A3 and other solute carrier (SLC) transporters in anthracycline-induced cardiotoxicity, and the suitability of SLC transporters as targets for cardioprotective drugs has not been investigated. METHODS: Six well-phenotyped, doxorubicin-treated pediatric patients from the original association study cohort were recruited again, and human induced pluripotent stem cell-derived cardiomyocytes were generated. Patient-specific doxorubicin-induced cardiotoxicity (DIC) was then characterized using assays of cell viability, activated caspase 3/7, and doxorubicin uptake. The role of SLC28A3 in DIC was then queried using overexpression and knockout of SLC28A3 in isogenic human-induced pluripotent stem cell-derived cardiomyocytes using a CRISPR/Cas9 (Clustered Regularly Interspaced Short Palindromic Repeats/CRISPR-associated protein 9). Fine-mapping of the SLC28A3 locus was then completed after SLC28A3 resequencing and an extended in silico haplotype and functional analysis. Genome editing of the potential causal variant was done using cytosine base editor. SLC28A3-AS1 overexpression was done using a lentiviral plasmid-based transduction and was validated using stranded RNA-sequencing after ribosomal RNA depletion. Drug screening was done using the Prestwick Chemical Library (n = 1200), followed by in vivo validation in mice. The effect of desipramine on doxorubicin cytotoxicity was also investigated in 8 cancer cell lines. RESULTS: Here, using the most commonly used anthracycline, doxorubicin, we demonstrate that patient-derived cardiomyocytes recapitulate the cardioprotective effect of the SLC28A3 locus and that SLC28A3 expression influences the severity of DIC. Using Nanopore-based fine-mapping and base editing, we identify a novel cardioprotective single nucleotide polymorphism, rs11140490, in the SLC28A3 locus; its effect is exerted via regulation of an antisense long noncoding RNA (SLC28A3-AS1) that overlaps with SLC28A3. Using high-throughput drug screening in patient-derived cardiomyocytes and whole organism validation in mice, we identify the SLC competitive inhibitor desipramine as protective against DIC. CONCLUSIONS: This work demonstrates the power of the human induced pluripotent stem cell model to take a single nucleotide polymorphism from a statistical association through to drug discovery, providing human cell-tested data for clinical trials to attenuate DIC.

An Assessment of Race as a Risk Factor for Doxorubicin-Related Cardiotoxicity in Diffuse Large B-Cell Lymphoma.

BACKGROUND: Doxorubicin carries a risk of congestive heart failure (CHF). Black race has been suggested as a risk factor for doxorubicin-related cardiotoxicity, but data are limited. We assessed whether HF occurs at higher rates in Black patients compared to White patients who receive doxorubicin for DLBCL, and evaluated race as an independent risk factor for the development of HF after adjusting for known risk factors. PATIENTS AND METHODS: We used SEER-Medicare to identify patients 66 years and older with DLBCL. We excluded patients with CHF documented prior to diagnosis with DLBCL. We assessed for hypertension, type 2 diabetes, coronary artery disease, and arrhythmias prior to diagnosis with DLBCL. The primary outcome was documented CHF at any point following DLBCL diagnosis. Secondary outcomes included CHF in the first year following diagnosis and death. We performed analyses additionally stratified by cumulative dose of doxorubicin. RESULTS: Our study population consisted of 8,604 patients (White 96.8%, Black 3.2%). In both Kaplan-Meier and competing risk analyses, we observed no significant difference in the incidence of CHF between Black and White patients, both before and after adjusting for covariates. Finally, we observed no significant differences in the incidence of CHF by race after stratification by cumulative doxorubicin dose. CONCLUSIONS: CHF is common following doxorubicin chemotherapy for DLBCL in older patients. No association was observed between Black race and the onset of heart failure in this setting. Rigorous screening for known clinical risk factors is likely more relevant than race in treatment selection and optimization.

Catecholamine-induced cardiotoxicity: A critical element in the pathophysiology of stroke-induced heart injury.

Cerebrovascular diseases such as ischemic stroke, brain hemorrhage, and subarachnoid hemorrhage provoke cardiac complications such as heart failure, neurogenic stress-related cardiomyopathy and Takotsubo cardiomyopathy. With regards to the pathophysiology of stroke-induced heart injury, several mechanisms have been postulated to contribute to this complex interaction between brain and heart, including damage from gut dysbiosis, immune and systematic inflammatory responses, microvesicle- and microRNA-mediated vascular injury and damage from a surge of catecholamines. All these cerebrovascular diseases may trigger pronounced catecholamine surges through diverse ways, including stimulation of hypothalamic-pituitary adrenal axis, dysregulation of autonomic system, and secretion of adrenocorticotropic hormone. Primary catecholamines involved in this pathophysiological response include norepinephrine (NE) and epinephrine. Both are important neurotransmitters that connect the nervous system with the heart, leading to cardiac damage via myocardial ischemia, calcium (Ca2+) overload, oxidative stress, and mitochondrial dysfunction. In this review, we will aim to summarize the molecular mechanisms behind catecholamine-induced cardiotoxicity including Ca2+ overload, oxidative stress, apoptosis, cardiac hypertrophy, interstitial fibrosis, and inflammation. In addition, we will focus on how synchronization among these pathways evokes cardiotoxicity.

TSSF-hERG: A machine-learning-based hERG potassium channel-specific scoring function for chemical cardiotoxicity prediction.

The human ether-à-go-go-related gene (hERG) encodes the Kv11.1 voltage-gated potassium ion (K+) channel that conducts the rapidly activating delayed rectifier current (IKr) in cardiomyocytes to regulate the repolarization process. Some drugs, as blockers of hERG potassium channels, cannot be marketed due to prolonged QT intervals, as well known as cardiotoxicity. Predetermining the binding affinity values between drugs and hERG through in silico methods can greatly reduce the time and cost required for experimental verification. In this study, we collected 9,215 compounds with AutoDock Vina's docking structures as training set, and collected compounds from four references as test sets. A series of models for predicting the binding affinities of hERG blockers were built based on five machine learning algorithms and combinations of interaction features and ligand features. The model built by support vector regression (SVR) using the combination of all features achieved the best performance on both tenfold cross-validation and external verification, which was selected and named as TSSF-hERG (target-specific scoring function for hERG). TSSF-hERG is more accurate than the classic scoring function of AutoDock Vina and the machine-learning-based generic scoring function RF-Score, with a Pearson's correlation coefficient (Rp) of 0.765, a Spearman's rank correlation coefficient (Rs) of 0.757, a root-mean-square error (RMSE) of 0.585 in a tenfold cross-validation study. All results demonstrated that TSSF-hERG would be useful for improving the power of binding affinity prediction between hERG and compounds, which can be further used for prediction or virtual screening of the hERG-related cardiotoxicity of drug candidates.

Macrophage-Dependent Interleukin-6-Production and Inhibition of IK Contributes to Acquired QT Prolongation in Lipotoxic Guinea Pig Heart.

In the heart, the delayed rectifier K current, IK, composed of the rapid (IKr) and slow (IKs) components contributes prominently to normal cardiac repolarization. In lipotoxicity, chronic elevation of pro-inflammatory cytokines may remodel IK, elevating the risk for ventricular arrythmias and sudden cardiac death. We investigated whether and how the pro-inflammatory interleukin-6 altered IK in the heart, using electrophysiology to evaluate changes in IK in adult guinea pig ventricular myocytes. We found that palmitic acid (a potent inducer of lipotoxicity), induced a rapid (~24 h) and significant increase in IL-6 in RAW264.7 cells. PA-diet fed guinea pigs displayed a severely prolonged QT interval when compared to low-fat diet fed controls. Exposure to isoproterenol induced torsade de pointes, and ventricular fibrillation in lipotoxic guinea pigs. Pre-exposure to IL-6 with the soluble IL-6 receptor produced a profound depression of IKr and IKs densities, prolonged action potential duration, and impaired mitochondrial ATP production. Only with the inhibition of IKr did a proarrhythmic phenotype of IKs depression emerge, manifested as a further prolongation of action potential duration and QT interval. Our data offer unique mechanistic insights with implications for pathological QT interval in patients and vulnerability to fatal arrhythmias.

Recent progress of iPSC technology in cardiac diseases.

It has been nearly 15 years since the discovery of human-induced pluripotent stem cells (iPSCs). During this time, differentiation methods to targeted cells have dramatically improved, and many types of cells in the human body can be currently generated at high efficiency. In the cardiovascular field, the ability to generate human cardiomyocytes in vitro with the same genetic background as patients has provided a great opportunity to investigate human cardiovascular diseases at the cellular level to clarify the molecular mechanisms underlying the diseases and discover potential therapeutics. Additionally, iPSC-derived cardiomyocytes have provided a powerful platform to study drug-induced cardiotoxicity and identify patients at high risk for the cardiotoxicity; thus, accelerating personalized precision medicine. Moreover, iPSC-derived cardiomyocytes can be sources for cardiac cell therapy. Here, we review these achievements and discuss potential improvements for the future application of iPSC technology in cardiovascular diseases.

Exercise intervention decreases acute and late doxorubicin-induced cardiotoxicity.

BACKGROUND: Doxorubicin (Dox) is one of the most effective chemotherapy agents used to treat adolescent and young adult sarcoma patients. Unfortunately, Dox causes cardiotoxicities that compromise long-term survival. We investigated whether exercise prevented cardiotoxicity and increased survival following myocardial infarction. METHODS: Juvenile mice received Dox, Dox + exercise (Exer), Dox then exercise or were exercised during and after Dox. Mice were evaluated by echocardiography and histology immediately after therapy and 12 weeks later. Mice subjected to permanent ligation of the left anterior descending artery 90 days after therapy were assessed for survival at 45 and 100 days. RESULTS: Mice treated with Dox, but not Dox + Exer, had decreased ejection fraction (EF) and fractional shortening (FS) immediately after Dox therapy, which continued to deteriorate over 12 weeks with the development of diastolic failure and fibrosis. Acute Dox-induced cardiotoxicity was documented by induction of autophagy and abnormal mitochondria and vascular architecture with decreased pericytes. These abnormalities persisted 12 weeks after therapy. These acute and late changes were not seen in the Dox + Exer group. Initiating exercise after Dox therapy promoted recovery of EF and FS with no functional or histologic evidence of Dox-induced damage 12 weeks after therapy. Survival rates at 100 days after MI were 67% for control mice, 22% for mice that received Dox alone, and 56% for mice that received Dox + Exer. CONCLUSIONS: Exercise inhibited both early and late Dox-induced cardiotoxicity and increased recovery from an ischemic event. Exercise interventions have the potential to decrease Dox-induced cardiac morbidity.

Acetylcholinesterase inhibitor ameliorates doxorubicin-induced cardiotoxicity through reducing RIP1-mediated necroptosis.

Doxorubicin is an effective chemotherapeutic drug, but causes cardiotoxicity which limits its use. Oxidative stress, mitochondrial dysfunction, and inflammation are closely implicated in doxorubicin-induced cardiotoxicity (DIC). Necroptosis, a new form of programmed cell death, was also upregulated by doxorubicin, leading to cardiomyocyte death and cardiac dysfunction. Donepezil, an acetylcholinesterase inhibitor, exerted cardioprotection against various heart diseases. However, its cardioprotective effects in DIC are still unknown. We hypothesized that donepezil reduces reactive oxygen species (ROS) production, mitochondrial dysfunction, mitochondrial dynamics imbalance, necroptosis, and apoptosis in DIC rats. Male Wistar rats were assigned to receive either normal saline solution (n = 8) or doxorubicin (3 mg/kg, 6 doses, n = 16) via intraperitoneal injection. The doxorubicin-treated rats were further subdivided to receive either sterile drinking water (n = 8) or donepezil (5 mg/kg/day, p.o., n = 8) for 30 days. At the end of the experiment, the left ventricular (LV) function was determined. Serum and heart tissue were collected to evaluate histological and biochemical parameters. Doxorubicin-treated rats exhibited higher levels of inflammatory cytokines and ROS production. Doxorubicin also impaired mitochondrial function, mitochondrial dynamics balance, mitophagy, and autophagy, which culminated in apoptosis. Furthermore, doxorubicin increased necroptosis as evidenced by increased phosphorylation of receptor-interacting protein kinase 1, receptor-interacting protein kinase 3, and mixed-lineage kinase domain-like. All of these mechanisms led to LV dysfunction. Interestingly, donepezil alleviated mitochondrial injury, mitophagy, autophagy, and cardiomyocyte death, leading to improved LV function in DIC. In conclusion, donepezil attenuated DIC-induced LV dysfunction by reducing mitochondrial damage, mitophagy, autophagy, apoptosis, and necroptosis.

[Research Progress of Immune Checkpoint Inhibitor-associated Myocarditis].

Immune checkpoint inhibitors (ICIs) is a negative regulatory factor antibody, which activates T cells to play an anti-tumor effect in immunotherapy, and can also cause immune-related adverse responses, thereby inducing a series of immune related adverse events (irAEs). Among these irAEs, although the incidence of ICIs-related myocarditis is very low, the fatality rate is significantly higher than other adverse reactions, close to 50%. Clinicians should be vigilant when applying ICIs, but the pathogenesis of ICIs-related myocarditis is still unclear. This article combines the recent research results of ICIs to summarize the mechanism and clinical manifestations of ICIs-related myocarditis, so as to improve clinicians' understanding of the adverse reactions.
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Successful treatment of severe myocardial injury complicated with refractory cardiogenic shock caused by AOPP using extracorporeal membrane oxygenation: A case report.

RATIONALE: Acute organophosphorus pesticide poisoning (AOPP) is a common critical illness observed in clinical practice, and severe AOPP can cause serious cardiac toxicity. PATIENT CONCERNS: This patient was a 43-year-old woman who was admitted to the emergency department with acute respiratory failure and hypotension 13 hours after oral consumption of 300 mL of phoxim pesticide. DIAGNOSES: Acute organophosphorus pesticide poisoning, cardiogenic shock. INTERVENTIONS: We conducted veno-arterial extracorporeal membrane oxygenation (VA-ECMO) therapy as the patient did not respond to conventional measures. OUTCOMES: This patient was successfully rescued with VA-ECMO therapy and discharged. LESSONS: We suggest that for patients with severe myocardial injury complicated with cardiogenic shock caused by AOPP, the use of VA-ECMO therapy can improve the prognosis.

Serial Changes in Cardiac Strain and Contractility After Hematopoietic Stem Cell Transplantation in Patients with Hematologic Malignancies.

Hematopoietic stem cell transplantation (HSCT) is occasionally associated with cardiac dysfunction during long-term follow-up. Global longitudinal strain (GLS) has emerged as an early predictor of cardiotoxicity associated with cancer therapy; however, the serial changes in GLS before and after HSCT have not been elucidated. To clarify the association between HSCT and GLS, we investigated serial changes in GLS before and after HSCT. We evaluated cardiac function before and 1, 3, and 6 months after HSCT in 38 consecutive HSCT patients enrolled in this study. Overall, GLS and left ventricular (LV) ejection fraction (EF) temporally decreased 1 month post-HSCT. LVEF completely recovered to baseline at 3 months after HSCT, whereas GLS partially recovered 6 months after HSCT. Except for five patients who died within 6 months, GLS values in the low EF group (LVEF ≤ 55% at 6 months post-HSCT, n = 6) were significantly and consistently lower than those in the normal EF group (LVEF > 55% at 6 months post-HSCT, n = 27) at any time during follow-up. These findings suggest that GLS before HSCT might be associated with a decrease in LVEF after HSCT in patients with hematologic malignancies. Further prospective and long-term data will be important for understanding the management of HSCT-associated cardiac dysfunction.

Using Chicken Embryo as a Powerful Tool in Assessment of Developmental Cardiotoxicities.

Chicken embryos are a classical model in developmental studies. During the development of chicken embryos, the time window of heart development is well-defined, and it is relatively easy to achieve precise and timely exposure via multiple methods. Moreover, the process of heart development in chicken embryos is similar to mammals, also resulting in a four-chambered heart, making it a valuable alternative model in the assessment of developmental cardiotoxicities. In our lab, the chicken embryo model is routinely used in the assessment of developmental cardiotoxicities following exposure to various environmental pollutants, including per- and polyfluoroalkyl substances (PFAS), particulate matter (PMs), diesel exhaust (DE) and nano materials. The exposure time can be freely selected based on the need, from the beginning of development (embryonic day 0, ED0) all the way to the day prior to hatch. The major exposure methods include air-cell injection, direct microinjection, and air-cell inhalation (originally developed in our lab), and the currently available endpoints include cardiac function (electrocardiography), morphology (histological assessments) and molecular biological assessments (immunohistochemistry, qRT-PCR, western blotting, etc.). Of course, the chicken embryo model has its own limitations, such as limited availability of antibodies. Nevertheless, with more laboratories starting to utilize this model, it can be used to make significant contributions to the study of developmental cardiotoxicities.

Maduramicin induces cardiotoxicity via Rac1 signaling-independent methuosis in H9c2 cells.

Maduramicin frequently induces severe cardiotoxicity in target and nontarget animals in clinic. Apoptotic and non-apoptotic cell death mediate its cardiotoxicity; however, the underlying non-apoptotic cell death induced by maduramicin remains unclear. In current study, a recently described non-apoptotic cell death "methuosis" caused by maduramicin was defined in mammalian cells. Rat myocardial cell H9c2 was used as an in vitro model, showing excessively cytoplasmic vacuolization upon maduramicin (0.0625-5 µg/mL) exposure for 24 h. Maduramicin-induced reversible cytoplasmic vacuolization of H9c2 cells in a time- and concentration-dependent manner. The vacuoles induced by maduramicin were phase lucent with single membrane and were not derived from the swelling of organelles such as mitochondria, endoplasmic reticulum, lysosome, and Golgi apparatus. Furthermore, maduramicin-induced cytoplasmic vacuoles are generated from micropinocytosis, which was demonstrated by internalization of extracellular fluid-phase marker Dextran-Alexa Fluor 488 into H9c2 cells. Intriguingly, these cytoplasmic vacuoles acquired some characteristics of late endosomes and lysosomes rather than early endosomes and autophagosomes. Vacuolar H+ -ATPase inhibitor bafilomycin A1 efficiently prevented the generation of cytoplasmic vacuoles and decreased the cytotoxicity of H9c2 cells triggered by maduramicin. Mechanism studying indicated that maduramicin activated H-Ras-Rac1 signaling pathway at both mRNA and protein levels. However, the pharmacological inhibition and siRNA knockdown of Rac1 rescued maduramicin-induced cytotoxicity of H9c2 cells but did not alleviate cytoplasmic vacuolization. Based on these findings, maduramicin induces methuosis in H9c2 cells via Rac-1 signaling-independent seriously cytoplasmic vacuolization.