Late cardiac effects of doxorubicin therapy for acute lymphoblastic leukemia in childhood

Clinical evaluation and outcome in heart failure patients receiving chemotherapy with different anti-cancer agents

BACKGROUND

The optimal strategy for modern chemotherapy should be based on a comprehensive approach for cancer patients with cardiovascular diseases. Therefore, cardio-oncology has received increasing attention owing to the cardiotoxic effects of anti-cancer therapies.

OBJECTIVES

We aimed to evaluate the clinical characteristics and outcomes of patients with heart failure (HF) who received chemotherapy compared with those of a matched cohort with HF who did not receive chemotherapy, using real-world HF data.

METHODS

This study was based on the Diagnosis Procedure Combination (DPC) database of the Japanese Registry of All Cardiac and Vascular Diseases (JROAD). We identified 1 328 113 patients who were hospitalized for HF between April 2012 and March 2021. The propensity score (PS) was estimated using a logistic regression model, with chemotherapy as the dependent variable, and a clinically score-matched analysis of 11 532 patients with HF with or without chemotherapy. The primary endpoint was readmission.

RESULTS

Colon, lung, breast and prostate cancers accounted for >60% of all cancer types. After PS matching, readmission was significantly more frequently observed in patients with chemotherapy than those without [odds ratio (OR), 1.26; 95% confidence interval (CI) 1.17-1.36, P < 0.01]. In particular, treatment with epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) (OR, 1.69; 95% CI 1.39-2.07), taxane (OR, 2.95; 95% CI 2.11-4.12), anthracyclines (OR, 1.86; 95% CI 1.19-2.90) and fluorouracil agents (OR, 1.65; 95% CI 1.18-2.30) caused a higher risk of readmission.

CONCLUSIONS

Medical providers need to monitor and follow-up patients with HF, depending on the characteristics of the anti-cancer agents and types of cancer.

Cell-Permeable Microprotein from Panax Ginseng Protects Against Doxorubicin-Induced Oxidative Stress and Cardiotoxicity

(1) Background: Doxorubicin (DOX) is a frontline chemotherapeutic, but its side-effects from oxidative stress, leading to cardiotoxicity, pose significant challenges to its clinical use. We recently discovered a novel family of proteolysis-resistant, cystine-dense, and cell-penetrating microproteins from Panax ginseng that we term ginsentides. Ginsentides, such as the 31-residue TP1, coordinate multiple biological systems to prevent vascular dysfunction and endoplasmic reticulum stress induced by internal and external stressors. (2) Methods: We assessed the protective effects of ginsentide TP1 on DOX-induced cardiotoxicity using both in vitro functional studies on H9c2 cardiomyocytes and in vivo animal models by zebrafish and ICR mouse models. In these models, we examined oxidative stress, apoptosis, intracellular calcium levels, mitochondrial function, inflammatory responses, and cardiac function. (3) Results: We show that ginsentide TP1 protects against DOX-induced cytotoxicity in the mitochondria-rich H9c2 cardiomyocytes and reduces myocardial injury in zebrafish and mice by mitigating oxidative stress, inflammation, calcium, and mitochondrial dysfunction, as well as apoptosis-mediated cell death. Importantly, TP1 preserves cellular homeostasis without compromising the anticancer potency of DOX in breast cancer cells. (4) Conclusions: our findings highlight a specific antioxidative function of ginsentide TP1 in managing DOX-induced cardiotoxicity during cancer treatment and provide a promising lead for developing cardioprotective peptides and microproteins against oxidative stress.

Longitudinal Trajectory of Left Ventricular Systolic Function in Children During Anthracycline-Based Chemotherapy Assessed by Noninvasive Myocardial Work

BACKGROUND

Noninvasive myocardial work (MW), which incorporates myocardial deformation and blood pressure, can be used to quantitatively evaluate left ventricular (LV) systolic function in children undergoing chemotherapy. However, the trajectories of MW indices (MWIs) in children during anthracycline-based chemotherapy remain unclear.

OBJECTIVE

To investigate the longitudinal trajectories of MWIs during anthracycline-based chemotherapy and compare the relative changes between MWIs and conventional echocardiographic parameters.

METHODS AND RESULTS

We retrospectively analyzed 441 echocardiograms from 102 children (median age, 7 years; 72 boys) with cancer who received anthracycline-based treatment. Conventional echocardiographic parameters (LV ejection fraction [LVEF] and global longitudinal strain [GLS]) and MWIs (global work index [GWI], global constructive work [GCW], global work efficiency [GWE], and global wasted work [GWW]) were obtained using GE EchoPAC software. The Mantel-Haenszel Chi-squared test revealed that GLS, GWI, GCW, and GWE all worsened during chemotherapy (all p < 0.05 for trend), with this deterioration appearing when the cumulative dose of anthracyclines reached 30-60 mg/m2. However, no significant trends were observed for LVEF and GWW (both p > 0.05 for trend). The linear mixed models indicated that GLS and GWE exhibited a consistent downward trend, whereas GWI and GCW experienced a plateau phase within the cumulative anthracycline dose range of 100-250 mg/m2. The relative changes in GWI and GCW were greater than those of GLS and GWE throughout chemotherapy.

CONCLUSION

Echocardiographic MW could provide a more sensitive assessment of anthracycline-induced cardiotoxicity (AIC) in children, allowing timely chemotherapy adjustment or cardioprotective measures to prevent cardiac dysfunction.

Characterization of anthracycline-induced cardiotoxicity by diffusion tensor magnetic resonance imaging

Anthracyclines are highly potent anti-cancer drugs, but their clinical use is limited by severe cardiotoxic side effects. The impact of anthracycline-induced cardiotoxicity (AIC) on left ventricular (LV) microarchitecture and diffusion properties remains unknown. This study sought to characterize AIC by cardiovascular magnetic resonance diffusion tensor imaging (DTI). Mice were treated with Doxorubicin (DOX; n = 16) for induction of AIC or saline as corresponding control (n = 15). Cardiac function was assessed via echocardiography at the end of the study period. Whole hearts (n = 8 per group) were scanned ex vivo by high-resolution DTI at 7 T. Results were correlated with histopathology and mass spectrometry imaging. Mice with AIC demonstrated systolic dysfunction (LVEF 52 ± 3% vs. 43 ± 6%, P < 0.001), impaired global longitudinal strain (-19.6 ± 2.0% vs. -16.6 ± 3.0%, P < 0.01), and cardiac atrophy (LV mass index [mg/mm], 4.3 ± 0.1 vs. 3.6 ± 0.2, P < 0.01). Regional sheetlet angles were significantly lower in AIC, whereas helix angle and relative helicity remained unchanged. In AIC, fractional anisotropy was increased (0.12 ± 0.01 vs. 0.14 ± 0.02, P < 0.05). DOX-treated mice displayed higher planar and less spherical anisotropy (CPlanar 0.07 ± 0.01 vs. 0.09 ± 0.01, P < 0.01; CSpherical 0.89 ± 0.01 vs. 0.87 ± 0.02, P < 0.05). CPlanar and CSpherical yielded good discriminatory power to distinguish between mice with and without AIC (c-index 0.91 and 0.84, respectively, P for both < 0.05). AIC is associated with regional changes in sheetlet angle but no major abnormalities of global LV microarchitecture. The geometric shape of the diffusion tensor is altered in AIC. DTI may provide a new tool for myocardial characterization in patients with AIC, which warrants future clinical studies to evaluate its diagnostic utility.

Sonopermeation With Size-sorted Microbubbles Synergistically Increases Survival and Enhances Tumor Apoptosis With L-DOX by Increasing Vascular Permeability and Perfusion in Neuroblastoma Xenografts

OBJECTIVE

Despite aggressive therapy, approximately 50% of patients with neuroblastoma (NB) fail to respond, and survivors endure lifelong toxicities. Sonopermeation increases drug uptake via cell bilayer disruption through focused ultrasound and microbubbles (MBs)-gas-filled, sound sensitive lipid spheres. MB response to a given ultrasound pulse (cavitation) varies according to MB size. We asked whether size-sorted MBs (SSMB) 4 to 5 µm in diameter will more consistently and predictably enhance doxorubicin uptake, compared with polydisperse MBs (PMB, 0.5-10 µm in diameter), thereby increasing drug delivery to NB xenografts.

METHODS

Human NB cells were implanted into the left kidney of nude mice and grown for 5 to 6 wk. Mice received sonopermeation alongside either PMB or SSMB at low (0.6 MPa) or high (2 MPa) negative pressures. Some mice also received different chemotherapy agents (doxorubicin, etoposide or cyclophosphamide). Circulating tumor cells were assessed by flow cytometry 1 h after treatment. Survival was assessed for up to 21 d, a subset of mice was euthanized 24 h after treatment for histological assessment of apoptosis, vascular lumen size and tight junctions.

RESULTS

Tumors treated with SSMB and high pressure showed synergy with liposomal doxorubicin (L-DOX) owing to increased vascular lumen and disruption of tight junctions, resulting in drug uptake, apoptosis, lack of tumor growth and increased survival. We found no difference in the numbers of circulating tumor cells.

CONCLUSION

Sonopermeation with SSMB at 2 MPa synergizes with L-DOX delivery, increasing apoptosis, perfusion and vascular permeability, suggesting that SSMB sonopermeation at high pressure is promising for NB-targeted treatment, especially in combination with L-DOX.

Risk of Cardiovascular Disease in Patients With Classical Hodgkin Lymphoma: A Danish Nationwide Register-Based Cohort Study

Risk of cardiovascular disease (CVD) in patients with classical Hodgkin lymphoma (cHL) undergoing contemporary treatment is unclear. cHL patients ≥ 18 years at diagnosis treated with doxorubicin-containing chemotherapy between 2000 and 2022 were matched 1:5 with comparators on birth year, sex, and Charlson Comorbidity Index at time of matching (score of 0 or ≥ 1). Cause-specific cumulative incidence of a composite of CVDs with corresponding 95% confidence intervals (CIs) were computed with death and lymphoma relapse as competing events (i.e., by censoring individuals at such occurrences) using the Aalen-Johansen estimator. A total of 1905 patients and 9525 comparators with a median follow-up of 10 years (interquartile range, [IQR]: 5.9-17.4). Median age was 39 years (IQR: 27-56), median cumulative doxorubicin dose was 250 mg/m2 (IQR: 200-300). The CVD cumulative incidences were 4.7% (95% CI: 3.6-5.7) for patients versus 2.6% (95% CI: 2.3-2.9) for comparators at 5 years, 8.9% (95% CI: 7.2-10.5) versus 5.5% (95% CI: 4.9-6.0) at 10 years, and 17.0% (95% CI: 14.1-19.9) versus 8.2% (95% CI: 7.4-9.0) at 15 years. CVD remains a substantial effect after contemporary treatment for cHL, suggesting that awareness of symptoms and a low threshold for referral to diagnostic examination are still important measures during survivorship.

Uncovering possible silent acquired long QT syndrome using exercise stress testing in long-term pediatric acute lymphoblastic leukemia survivors

An example of chemotherapy-induced cardiotoxicity in cancer survivors is acquired long QT syndrome (aLQTS), which may cause serious yet preventable life-threatening consequences. Our objective was to identify and characterize childhood acute lymphoblastic leukemia (ALL) survivors with possible aLQTS using maximal exercise testing. In this cross-sectional study with exploratory analysis, a total of 250 childhood ALL survivors were evaluated for abnormal QT interval prolongation using the McMaster cycle exercise test. A total of 198 survivors (102 males; 96 females), having reached theirV ̇ O 2 peak (mean 32.1 ± 8.4 mL/kg/min; range 15.5-57.8 mL/kg/min), were included in our analyses. Two survivors were excluded for possible congenital LQTS. QT intervals were corrected for heart rate using the Bazett, Fridericia, and Rautaharju formulas at rest (supine, sitting, and standing positions), at the end of each stage of the CPET, and at 1, 3, and 5 minutes into the recovery period. The corrected QT (QTc) of borderline (n = 37) and long QT survivors (n = 20) was significantly longer than normal survivors (n = 141) at rest, exercise, and recovery. Out of 57 survivors presenting an abnormal QTc prolongation, 40 survivors (70%) showed no QT interval anomalies at rest but developed various anomalies during exercise. No significant differences were found between the groups for any of the measured clinical characteristics or cardiac parameters. The standardization of exercise testing in the regular follow-up of oncology patients is necessary for appropriate cardiac prevention and surveillance to enhance the health and quality of life of the ever-increasing number of cancer survivors.

eEF2K alleviates doxorubicin-induced cardiotoxicity by inhibiting GSK3β and improving autophagy dysfunction

Doxorubicin-induced cardiotoxicity (DIC) poses a threat to the health and prognosis of cancer patients. It is important to find a safe and effective method for the prevention and treatment of DIC. eEF2K, which is a highly conserved α-kinase, is thought to be a therapeutic target for several human diseases. Nonetheless, it is still uncertain if eEF2K contributes to the cardiotoxic effects caused by doxorubicin (DOX). Our research revealed that eEF2K expression decreased in the DIC. eEF2K was overexpressed through adeno-associated virus in vivo and adenovirus in vitro, which presented alleviative cardiomyocyte death and cell atrophy induced by DOX. Autophagy dysfunction is one of important mechanisms in DIC. As a result, autophagic function was evaluated using Transmission electron microscopy in vivo, as well as LysoSensor and mRFPGFP-LC3 puncta in vitro. eEF2K overexpression improves DOX-induced autophagy blockade. In addition, eEF2K knockdown aggravated autophagy blockade and cardiomyocyte injury in DIC model. eEF2K also phosphorylated and inhibited GSK3β in DIC model. AR-A014418 (ARi), known for selectively inhibiting GSK3β, countered the effects of eEF2K knockdown, which aggravated autophagy blockade in the DIC. In conclusion, this study proposes that eEF2K alleviates DIC by inhibiting GSK3β and improving autophagy dysfunction. eEF2K is a promising therapeutic target against DIC.

The Effects of Pediatric Acute Lymphoblastic Leukemia Treatment on Cardiac Repolarization

Background: In recent years, cardiac dysfunction in childhood cancer survivors has become an important issue. Studies are focusing on identifying means for the early identification of patients at risk. Considering this, our study aims to investigate 24-hour Holter electrocardiogram (ECG) repolarization changes throughout doxorubicin (DOX) and cyclophosphamide (CPM) administration in pediatric patients treated for acute lymphoblastic leukemia (ALL). Methods: This was an investigator-driven, single-center, prospective, observational study. Enrolled children had a baseline bedside ECG examination performed before starting chemotherapy (T0). Serial Holter ECG examinations were conducted at three moments during their treatment protocol: day 8 (T1), day 29 (T2), and day 36 (T3). This study evaluated several ECG repolarization parameters, such as the QT interval, corrected QT interval (QTc), and QTc dispersion, as well as ST segment variations. Results: We evaluated 37 children diagnosed with ALL. The T0 examination revealed that over a third of patients had a resting heart rate (HR) outside the normal range for their age and sex. During chemotherapy, statistically significant increases in both HR as well as QT and QTc dispersion values were noticed, especially during the first DOX administration. What is more, a significant increase in the percentage of patients with ST segment depression from T1 to T2 and T3 was noticed. Rhythm disturbances were rare in the study population, with only a few patients presenting ventricular or supraventricular extrasystoles. Conclusions: This study reveals silent repolarization changes occurring early during anticancer treatment in children treated for ALL. These findings could aid in a better understanding of the cardiac toxicity mechanism, and they could potentially improve cardiac risk stratification for oncologic patients. Because of the small number of patients, our results need to be validated by larger studies.

The significance of the apelinergic system in doxorubicin-induced cardiotoxicity

Cancer is the leading cause of death worldwide, and the number of cancer-related deaths is expected to increase. Common types of cancer include skin, breast, lung, prostate, and colorectal cancers. While clinical research has improved cancer therapies, these treatments often come with significant side effects such as chronic fatigue, hair loss, and nausea. In addition, cancer treatments can cause long-term cardiovascular complications. Doxorubicin (DOX) therapy is one example, which can lead to decreased left ventricle (LV) echocardiography (ECHO) parameters, increased oxidative stress in cellular level, and even cardiac fibrosis. The apelinergic system, specifically apelin and its receptor, together, has shown properties that could potentially protect the heart and mitigate the damages caused by DOX anti-cancer treatment. Studies have suggested that stimulating the apelinergic system may have therapeutic benefits for heart damage induced by DOX. Further research in chronic preclinical models is needed to confirm this hypothesis and understand the mechanism of action for the apelinergic system. This review aims to collect and present data on the effects of the apelinergic system on doxorubicin-induced cardiotoxicity.

Empagliflozin attenuates doxorubicin-induced cardiotoxicity by inhibiting the JNK signaling pathway

BACKGROUND

Sodium-glucose cotransporter-2 inhibitors, such as empagliflozin, are pivotal therapies for heart failure. However, the effect of empagliflozin on doxorubicin-related cardiac dysfunction remains unclear.

METHODS

Human induced pluripotent stem cell- and embryonic stem cell-derived cardiomyocytes were used to investigate the direct effect of empagliflozin on human cardiomyocytes. Then, the c-Jun amino-terminal kinases (JNK) inhibitor SP600125 was administered to the doxorubicin cardiotoxicity model in vitro and in vivo to investigate the role of JNK in empagliflozin.

RESULTS

In human stem cell-derived cardiomyocytes, pretreatment with empagliflozin attenuated doxorubicin-induced cleavage of caspase 3 and other apoptosis markers. Empagliflozin significantly attenuated doxorubicin-induced phosphorylation of JNK and p38. Inhibiting the phosphorylation of JNK (SP600125) or STAT3 attenuated doxorubicin-induced apoptosis, but inhibiting the phosphorylation of p38 did not. SP600125 inhibits the phosphorylation of STAT3 (S727), and a STAT3 (Y705) inhibitor also inhibits the phosphorylation of JNK. Empagliflozin and SP600125 attenuated doxorubicin-induced increases in reactive oxygen species (ROS) and decreases in oxidized nicotinamide adenine dinucleotide (NAD+). In animal studies, empagliflozin and SP600125 attenuated doxorubicin-induced cardiac dysfunction and fibrosis.

CONCLUSIONS

Empagliflozin attenuated doxorubicin-induced apoptosis by inhibiting the phosphorylation of JNK and its downstream signaling pathways, including ROS and NAD+.

Cardiac Disease in Childhood Cancer Survivors Treated With Radiation Therapy: A PENTEC Comprehensive Review

PURPOSE

Radiation therapy (RT) is an essential component in the treatment of many pediatric malignancies. Thoracic RT may expose the heart to radiation dose and thereby increase the risk of late cardiac disease. This comprehensive review from the Pediatric Normal Tissue Effects in the Clinic (PENTEC) initiative focused on late cardiac disease in survivors of childhood cancer treated with RT.

METHODS AND MATERIALS

This systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology. We identified 1496 articles; 4 were included for dose-response modeling between mean cardiac radiation dose and risk of late coronary artery disease, heart failure (HF), valvular disease, and any cardiac disease.

RESULTS

For each 10-Gy increase in corrected mean cardiac radiation dose in 1.8- to 2.0-Gy fractions, we estimated a hazard ratio of 2.01 (95% confidence interval [CI], 1.79-2.25) for coronary artery disease, of 1.87 (95% CI, 1.70-2.06) for HF, of 1.87 (95% CI, 1.78-1.96) for valvular disease, and of 1.88 (95% CI, 1.75-2.03) for any cardiac disease. From the same model, for each 100-mg/m2 increase in cumulative anthracycline dose, the hazard ratio for the development of HF was 1.93 (95% CI, 1.58-2.36), equivalent to an increase in mean heart dose of approximately 10.5 Gy. Other nontreatment factors were inconsistently reported in the analyzed articles.

CONCLUSIONS

Radiation dose to the heart increases the risk of late cardiac disease, but survivors of childhood cancer who receive a mean dose <10 Gy at standard fractionation are at low absolute risk (<∼2% approximately 30 years after exposure) of late cardiac disease in the absence of anthracycline exposure. Minimizing cardiac radiation dose is especially relevant in children receiving anthracyclines. When cardiac sparing is not possible, we recommend prioritizing target coverage. It is likely that individual cardiac substructure doses will be a better predictor of specific cardiac diseases than mean dose, and we urge the pediatric oncology community to further study these relationships.

Early myocardial injury in children on doxorubicin for cancer chemotherapy: a cross-sectional study in a tertiary referral centre in Kenya

INTRODUCTION

Use of doxorubicin, an anthracycline chemotherapeutic agent has been associated with late-occurring cardiac toxicities. Detection of early-occurring cardiac effects of cancer chemotherapy is essential to prevent occurrence of adverse events including toxicity, myocardial dysfunction, and death.

OBJECTIVE

To investigate the prevalence of elevated cardiac troponin T (cTnT) and associated factors of myocardial injury in children on doxorubicin cancer chemotherapy.

METHODS

Design: A cross-sectional study.

SETTING AND SUBJECTS

A hospital-based study conducted on children aged 1-month to 12.4-years who had a diagnosis of cancer and were admitted at Kenyatta National Hospital (KNH).

INTERVENTIONS AND OUTCOMES

The patients underwent Echocardiography (ECHO) before their scheduled chemotherapy infusion. Twenty-four (24) hours after the chemotherapy infusion the patients had an evaluation of the serum cardiac troponin T (cTnT) and a repeat ECHO. Myocardial injury was defined as cTnT level > 0.014 ng/ml or a Fractional Shortening (FS) of < 29% on ECHO.

RESULTS

One hundred (100) children were included in the final analysis. Thirty-two percent (32%) of the study population had an elevated cTnT. A cumulative doxorubicin dose of > 175 mg/m2 was significantly associated with and elevated cTnT (OR, 10.76; 95% CI, 1.18-97.92; p = 0.035). Diagnosis of nephroblastoma was also associated with an elevated cTnT (OR, 3.0; 95% CI, 1.23-7.26) but not statistically significant (p = 0.105). Nine percent (9%) of the participants had echocardiographic evidence of myocardial injury.

CONCLUSION

When compared to echocardiography, elevated levels of cTnT showed a higher association with early-occurring chemotherapy-induced myocardial injury among children on cancer treatment at a tertiary teaching and referral hospital in Kenya.

Dyslipidemia and cardiovascular disease among childhood cancer survivors: a St. Jude Lifetime Cohort report

BACKGROUND

Childhood cancer survivors have increased risk of dyslipidemia and atherosclerotic cardiovascular disease (CVD). The aim of this study was to evaluate the prevalence and associated cardiovascular risks of specific lipid abnormalities among childhood cancer survivors.

METHODS

Comprehensive lipid panel measurements were obtained from 4115 5-year survivors, with 3406 (mean age at evaluation = 35.2 years, SD = 10.4 years) not having previous dyslipidemia diagnosis, as well as 624 age, sex, and race and ethnicity matched community controls.

RESULTS

Previously undiagnosed dyslipidemia with abnormal low-density lipoprotein (LDL) cholesterol (>160 mg/dL), non-high density lipoprotein (HDL) cholesterol (>190 mg/dL), HDL cholesterol (<40 mg/dL for men, <50 mg/dL for women), and triglycerides (>150 mg/dL) were identified in 4%, 6%, 30%, and 17%, respectively. Survivors without previous dyslipidemia diagnosis had higher LDL cholesterol and non-HDL cholesterol and lower HDL cholesterol than community controls. Cranial radiotherapy (relative risk [RR] = 2.2, 95% confidence interval [CI] = 1.6 to 3.0 for non-HDL cholesterol) and total body irradiation for hematopoietic cell transplantation (RR = 6.7, 95% CI = 3.5 to 13.0 for non-HDL cholesterol; RR = 9.9, 95% CI = 6.0 to 16.3 for triglycerides) were associated with greater risk of dyslipidemia. Diagnoses of low HDL cholesterol (hazard ratio [HR] = 2.9, 95% CI = 1.8 to 4.7) and elevated triglycerides (HR = 3.1, 95% CI = 1.9 to 5.1) were associated with increased risk for myocardial infarction, and diagnoses of high LDL cholesterol (HR = 2.2, 95% CI = 1.3 to 3.7), high non-HDL cholesterol (HR = 2.2, 95% CI = 1.3 to 3.7), low HDL cholesterol (HR = 3.9, 95% CI = 2.8 to 5.4), and elevated triglycerides (HR = 3.8, 95% CI = 2.7 to 5.5) were associated with increased risk for cardiomyopathy.

CONCLUSIONS

Previously undiagnosed dyslipidemia among childhood cancer survivors was associated with increased risk for myocardial infarction and cardiomyopathy. Comprehensive dyslipidemia evaluation and treatment are needed to reduce cardiovascular morbidity in this population.

QTc intervals at rest and during exercise assessed by group correction formulas in survivors of childhood acute lymphoblastic leukemia

INTRODUCTION

Early signs of subclinical cardiac damage must be identified before they turn into clinical manifestations. Tailoring a formula is relevant for precise QTc evaluation in childhood acute lymphoblastic leukemia (ALL) survivors considering they are at risk of long-term cardiac problems. Therefore, we aim to develop group heart rate correction formulas for QT intervals in childhood ALL survivors at rest and during exercise, and to assess the applicability of these methods across a variety of risk groups exposed to diverse chemotherapy dosages.

METHODS

Two hundred and fifty childhood ALL survivors in the PETALE study were classified into 3 groups depending on their prognostic risk group. ECG measurements (QT and RR intervals) were made at rest and during a cardiopulmonary exercise test. QT correction for heart rate was applied using 5 different formulas, which included 2 previously published formulas and 3 group-specific formulas for each sex.

RESULTS

The QT/RR relation showed 2 different curves between rest and during exercise, which was worse for females. Group-specific QTc formulas allowed adequate heart rate-corrected QT interval, independently of the cumulative dose of doxorubicin received during treatment. Group-specific formulas showed significantly shorter QTc intervals than QTc from Bazett's formula. QTc (Bazett's formula) values surpassed the established clinical norm in 22 males (11%) and 22 females (11%), with a majority occurring during exercise, affecting 15 males (7.5%) and 10 females (5%).

CONCLUSION

This study shows the applicability of personalized group correction of QT/RR data in childhood ALL survivors. Our comprehensive assessments (spanning rest, exercise, and recovery) is an effective approach for risk stratification of cardiac complications in childhood ALL survivors.

A review of the pathophysiological mechanisms of doxorubicin-induced cardiotoxicity and aging

The population of cancer survivors is rapidly increasing due to improving healthcare. However, cancer therapies often have long-term side effects. One example is cancer therapy-related cardiac dysfunction (CTRCD) caused by doxorubicin: up to 9% of the cancer patients treated with this drug develop heart failure at a later stage. In recent years, doxorubicin-induced cardiotoxicity has been associated with an accelerated aging phenotype and cellular senescence in the heart. In this review we explain the evidence of an accelerated aging phenotype in the doxorubicin-treated heart by comparing it to healthy aged hearts, and shed light on treatment strategies that are proposed in pre-clinical settings. We will discuss the accelerated aging phenotype and the impact it could have in the clinic and future research.

Anthracycline Toxicity: Light at the End of the Tunnel?

Anthracycline-induced cardiotoxicity (AIC) is a serious and common side effect of anthracycline therapy. Identification of genes and genetic variants associated with AIC risk has clinical potential as a cardiotoxicity predictive tool and to allow the development of personalized therapies. In this review, we provide an overview of the function of known AIC genes identified by association studies and categorize them based on their mechanistic implication in AIC. We also discuss the importance of functional validation of AIC-associated variants in human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) to advance the implementation of genetic predictive biomarkers. Finally, we review how patient-specific hiPSC-CMs can be used to identify novel patient-relevant functional targets and for the discovery of cardioprotectant drugs to prevent AIC. Implementation of functional validation and use of hiPSC-CMs for drug discovery will identify the next generation of highly effective and personalized cardioprotectants and accelerate the inclusion of approved AIC biomarkers into clinical practice.

The Role of RARG rs2229774, SLC28A3 rs7853758, and UGT1A6*4 rs17863783 Single-nucleotide Polymorphisms in the Doxorubicin-induced Cardiotoxicity in Solid Childhood Tumors

BACKGROUND

The objective of our study was to determine the role of retinoic acid receptor gamma (RARG) rs2229774, SLC28A3 rs7853758, and UGT1A6*4 rs17863783 single-nucleotide polymorphisms in identifying the risk of doxorubicin-induced cardiotoxicity in pediatric solid tumors.

METHODS

A total of 60 pediatric patients who had completed their treatment at least 2 years ago and 50 healthy children matched for age and sex were included in the study. All patients were evaluated for cardiotoxicity by echocardiography. The blood samples were analyzed for RARG rs2229774, SLC28A3 rs7853758, and UGT1A6*4 rs17863783 polymorphisms. Demographic characteristics, echocardiographic parameters, and genetic results of both groups were evaluated.

RESULTS

In our study, the RARG rs2229774 AA genotype was associated with cardiotoxicity ( P =0.017). The SLC28A3 rs7853758 AA+GA genotype was detected more frequently in patients who did not develop cardiotoxicity ( P <0.023). Furthermore, the frequency of the SLC28A3 rs7853758 A allele was significantly lower in the cardiotoxicity group ( P <0.025).

CONCLUSIONS

This is the first study in the Turkish population to investigate the correlation between the cardiotoxicity risk and 3 marker genes, which are recommended in the pharmacogenetic guideline for risk assessment in pediatric doxorubicin patients. The gene polymorphism that we investigated in this study was useful for the early prediction of cardiotoxicity risk.

Evaluation of left ventricular function and volume by two-dimensional echocardiography in a pediatric population: Correlation with cardiac magnetic resonance imaging

Background

Echocardiographic quantification of left ventricular (LV) volume and ejection fraction (EF) is widely used in the pediatric population. However, there is no consensus on the most accurate method of quantifying ventricular volumes and systolic function.

Purpose

The purpose of this study is to compare two commonly used echocardiographic methods for the evaluation of LV volume and quantification of EF, the five-sixth area-length (5/6 AL) and the modified biplane Simpson (BS), to cardiac magnetic resonance (CMR) imaging in children.

Methods

CMR studies were paired with echocardiograms and retrospectively analyzed in children 18 years of age and younger. Studies performed more than 3 months between modalities, patients with congenital heart disease, and patients who had changes in medication regimen between corresponding CMR and echocardiograms were excluded. LV volumes and EF were calculated using the 5/6 AL and BS methods and compared to volumes and EF measured on corresponding CMR studies. Subgroup analyses were conducted based on LV function, pathology, and weight.

Results

We retrospectively analyzed 53 CMR and corresponding echocardiogram studies (23 studies for myocarditis and 30 studies for cardiomyopathy) in 46 patients. LVEF derived by both echocardiographic methods showed a good correlation to CMR (5/6 AL r = 0.85 and BS r = 0.82). However, both echocardiographic methods overestimated LVEF and underestimated LV volumes when compared to CMR.

Conclusion

Left ventricular volumes and EF, as measured by echocardiography, correlate well with CMR measurements. Echocardiography underestimates LV systolic and diastolic volumes and overestimates LVEF. While echocardiography is a good surrogate for estimating LVEF, CMR should be considered in patients for whom accurate measurements are needed for critical clinical decision-making.

SGK1 is involved in doxorubicin-induced chronic cardiotoxicity and dysfunction through activation of the NFκB pathway

Breast cancer is the predominant cancer among women worldwide, and chemotherapeutic agents, such as doxorubicin (DOX), have the potential to significantly prolong survival, albeit at the cost of inducing severe cardiovascular toxicity. Inflammation has emerged as a crucial biological process contributing to the remodeling of cardiovascular toxicity. The role of serum glucocorticoid kinase 1 (SGK1) in various inflammatory diseases has been extensively investigated. Here, we studied the molecular mechanisms underlying the function of SGK1 in DOX-induced cardiotoxicity in HL-1 cardiomyocyte cell lines and in a tumor-bearing mouse model. SGK1 was upregulated in the DOX-induced cardiotoxicity model, accompanied by increased levels of inflammatory factors. Furthermore, inhibition of SGK1 suppresses the phosphorylation of nuclear factor-kappa B (NFκB) in cardiomyocytes, which inhibits the production of inflammatory factors and apoptosis of cardiomyocytes, and has cardioprotective effects. Simultaneously, small interfering RNA targeting SGK1 inhibited the proliferation of breast cancer cells. Conversely, overexpression of SGK1 increases the phosphorylation of NFκB and aggravates myocardial injury. In conclusion, our study demonstrates that SGK1 promotes DOX-induced cardiac inflammation and apoptosis by promoting NFκB activity. Our results indicate that inhibiting SGK1 might be an effective treatment strategy that can provide both tumor-killing and cardioprotective functions. Further in vivo research is needed to fully elucidate the effects and mechanisms of combination therapy with SGK1 inhibitors and DOX in breast cancer treatment.

Echocardiographic Parameters Associated With Cardiorespiratory Fitness and Physical Activity in Childhood Acute Lymphoblastic Leukemia Survivors

BACKGROUND

Children's exposure to chemotherapeutic agents causes several long-term adverse effects but physical activity has been evidenced to be an effective strategy to improve cardiac function. This cross-sectional study aimed to explore the association between physical activity levels, cardiorespiratory fitness, and cardiac parameters measured by echocardiography.

METHODS

Participants were 216n childhood acute lymphoblastic leukemia survivors who underwent a maximal cardiopulmonary exercise test and self-reported their daily minutes of moderate to vigorous physical activity. They underwent a complete transthoracic echocardiographic assessment. Systolic and diastolic function analysis and strain images analysis were performed. The associations were studied through the preventive fraction (examined with univariate crude and adjusted logistic regression models) of regular physical activity (≥150 min·wk-1) and adequate cardiorespiratory fitness levels (above the median ≥ 32.0 mL·kg-1·min-1) on cardiac parameters.

RESULTS

Crude analysis shows that regular physical activity was associated with a significant preventive fraction in mitral E/A ratio (56%; P = .013), while adjusted analyses highlighted a nonsignificant reduction of 74% to 37% in the prevalence of cardiac parameters associated with physical activity. Similar associations of adequate cardiorespiratory fitness on cardiac parameters were observed. Adjusted analyses revealed a nonsignificant reduction of 7% to 86% in the prevalence of cardiac parameters associated with cardiorespiratory fitness.

CONCLUSION

This study reports that regular physical activity and adequate cardiorespiratory fitness were associated with a higher preventive fraction. Thus, engaging in physical activity prevents childhood acute lymphoblastic leukemia survivors' cardiac dysfunctions. These findings are novel and clinically relevant in pediatric cardiooncology and provide additional evidence to strengthen the benefits of exercise as long-term care in childhood cancer survivors.

Anthracycline's Effects on Heart Rate Variability in Children with Acute Lymphoblastic Leukemia: Early Toxicity Signs-Pilot Study

Anthracycline treatments are known to cause cardiotoxic long-term side effects in cancer survivors. Recently, a decrease in heart rate variability (HRV) has been identified in these patients, signaling autonomic dysfunction and altered cardiac fitness. This study aimed at evaluating changes in HRV in children treated with anthracyclines. A total of 35 pediatric patients with acute lymphoblastic leukemia were evaluated by means of a 24 h Holter ECG, at baseline and after reaching half the total cumulative dose of doxorubicin equivalent (120 mg/m2). Parameters of HRV were assessed, as well as any arrhythmic episodes, bradycardia and tachycardia percentages. The results showed a significant decrease in both time-domain and frequency-domain HRV parameters, following anthracycline treatment. The low-frequency (LF) to high-frequency (HF) parameters' ratio also displayed a significant difference (p = 0.035), suggestive of early cardiac autonomic dysfunction. Of note, none of the patients presented symptoms of heart disease or elevated troponins, and only two patients presented echocardiographic signs of diastolic dysfunction. The present study showed that cardiac autonomic nervous system regulation is compromised in children treated with anthracyclines even before reaching the total cumulative dose. Therefore, HRV parameters could be the first indicators of subclinical cardiac toxicity, making Holter ECG monitoring of the oncological patient a necessity.

Cardiac electrical abnormalities in childhood acute lymphoblastic leukemia survivors: a systematic review

PURPOSE

The aim was to provide evidence about the prevalence, incidence, and risk factors of cardiac electrical abnormalities in childhood acute lymphoblastic leukemia (ALL) survivors.

METHODS

We included all original studies reporting the incidence and/or prevalence of cardiac electrical abnormalities and/or risk factors associated with cardiac electrical abnormalities in childhood ALL survivors (< 21 years old at the time of their initial cancer diagnosis) who were post-treatment. Searches of the databases PubMed, Ovid MEDLINE(R) and Epub Ahead of Print, In-Process, In-Data-Review & Other Non-Indexed Citations, Daily and Versions(R), Ovid All EBM Reviews, Ovid Embase, and ISI Web of Science were completed in May 2023. The risk of bias was assessed using the standard JBI critical appraisal checklists.

RESULTS

The 11 studies included in this review (N = 1,264 participants) evaluated various parameters, including different cardiac electrical abnormalities. Five studies reported heart rate abnormalities (0-68%), six reported repolarization disorders (0-30%), two reported depolarization disorders (0-1%), seven reported rhythm disturbances or abnormalities (0-100%), four reported conduction disorders (0-10%), and three reported unclassified abnormalities (1-38%). No risk factors were reported.

CONCLUSIONS

Electrical heart problems have been observed in childhood ALL survivors after completion of treatment. Large prospective studies in childhood ALL survivors, clear definitions of cardiac electrical abnormalities, and comparison with a control group are warranted.

IMPLICATIONS FOR CANCER SURVIVORS

Cardiac electrical abnormalities induced by chemotherapy-related cardiotoxicity in the growing population of childhood ALL survivors need to be better characterized to ensure better long-term follow-up and improve overall survival rate.

Acute and early-onset cardiotoxicity in children and adolescents with cancer: a systematic review

BACKGROUND

Cardiotoxicity is among the most important adverse effects of childhood cancer treatment. Anthracyclines, mitoxantrone and radiotherapy involving the heart are its main causes. Subclinical cardiac dysfunction may over time progress to clinical heart failure. The majority of previous studies have focused on late-onset cardiotoxicity. In this systematic review, we discuss the prevalence and risk factors for acute and early-onset cardiotoxicity in children and adolescents with cancer treated with anthracyclines, mitoxantrone or radiotherapy involving the heart.

METHODS

A literature search was performed within PubMed and reference lists of relevant studies. Studies were eligible if they reported on cardiotoxicity measured by clinical, echocardiographic and biochemical parameters routinely used in clinical practice during or within one year after the start of cancer treatment in ≥ 25 children and adolescents with cancer. Information about study population, treatment, outcomes of diagnostic tests used for cardiotoxicity assessment and risk factors was extracted and risk of bias was assessed.

RESULTS

Our PubMed search yielded 3649 unique publications, 44 of which fulfilled the inclusion criteria. One additional study was identified by scanning the reference lists of relevant studies. In these 45 studies, acute and early-onset cardiotoxicity was studied in 7797 children and adolescents. Definitions of acute and early-onset cardiotoxicity prove to be highly heterogeneous. Prevalence rates varied for different cardiotoxicity definitions: systolic dysfunction (0.0-56.4%), diastolic dysfunction (30.0-100%), combinations of echocardiography and/or clinical parameters (0.0-38.1%), clinical symptoms (0.0-25.5%) and biomarker levels (0.0-37.5%). Shortening fraction and ejection fraction significantly decreased during treatment. Cumulative anthracycline dose proves to be an important risk factor.

CONCLUSIONS

Various definitions have been used to describe acute and early-onset cardiotoxicity due to childhood cancer treatment, complicating the establishment of its exact prevalence. Our findings underscore the importance of uniform international guidelines for the monitoring of cardiac function during and shortly after childhood cancer treatment.

The Protective Role of Glutathione against Doxorubicin-Induced Cardiotoxicity in Human Cardiac Progenitor Cells

This study investigated the protective effect of glutathione (GSH), an antioxidant drug, against doxorubicin (DOX)-induced cardiotoxicity. Human cardiac progenitor cells (hCPCs) treated with DOX (250 to 500 nM) showed increased viability and reduced ROS generation and apoptosis with GSH treatment (0.1 to 1 mM) for 24 h. In contrast to the 500 nM DOX group, pERK levels were restored in the group co-treated with GSH and suppression of ERK signaling improved hCPCs' survival. Similarly to the previous results, the reduced potency of hCPCs in the 100 nM DOX group, which did not affect cell viability, was ameliorated by co-treatment with GSH (0.1 to 1 mM). Furthermore, GSH was protected against DOX-induced cardiotoxicity in the in vivo model (DOX 20 mg/kg, GSH 100 mg/kg). These results suggest that GSH is a potential therapeutic strategy for DOX-induced cardiotoxicity, which performs its function via ROS reduction and pERK signal regulation.

Intermediate Molecular Phenotypes to Identify Genetic Markers of Anthracycline-Induced Cardiotoxicity Risk

Cardiotoxicity due to anthracyclines (CDA) affects cancer patients, but we cannot predict who may suffer from this complication. CDA is a complex trait with a polygenic component that is mainly unidentified. We propose that levels of intermediate molecular phenotypes (IMPs) in the myocardium associated with histopathological damage could explain CDA susceptibility, so variants of genes encoding these IMPs could identify patients susceptible to this complication. Thus, a genetically heterogeneous cohort of mice (n = 165) generated by backcrossing were treated with doxorubicin and docetaxel. We quantified heart fibrosis using an Ariol slide scanner and intramyocardial levels of IMPs using multiplex bead arrays and QPCR. We identified quantitative trait loci linked to IMPs (ipQTLs) and cdaQTLs via linkage analysis. In three cancer patient cohorts, CDA was quantified using echocardiography or Cardiac Magnetic Resonance. CDA behaves as a complex trait in the mouse cohort. IMP levels in the myocardium were associated with CDA. ipQTLs integrated into genetic models with cdaQTLs account for more CDA phenotypic variation than that explained by cda-QTLs alone. Allelic forms of genes encoding IMPs associated with CDA in mice, including AKT1, MAPK14, MAPK8, STAT3, CAS3, and TP53, are genetic determinants of CDA in patients. Two genetic risk scores for pediatric patients (n = 71) and women with breast cancer (n = 420) were generated using machine-learning Least Absolute Shrinkage and Selection Operator (LASSO) regression. Thus, IMPs associated with heart damage identify genetic markers of CDA risk, thereby allowing more personalized patient management.

Substrate oxidation during exercise in childhood acute lymphoblastic leukemia survivors

Children with acute lymphoblastic leukemia (ALL) are at high risk of developing long-term cardiometabolic complications during their survivorship. Maximal fat oxidation (MFO) is a marker during exercise of cardiometabolic health, and is associated with metabolic risk factors. Our aim was to characterize the carbohydrate and fat oxidation during exercise in childhood ALL survivors. Indirect calorimetry was measured in 250 childhood ALL survivors to quantify substrate oxidation rates during a cardiopulmonary exercise test. A best-fit third-order polynomial curve was computed for fat oxidation rate (mg/min) against exercise intensity (%V ̇ O2peak) and was used to determine the MFO and the peak fat oxidation (Fatmax). The crossover point was also identified. Differences between prognostic risk groups were assessed (ie, standard risk [SR], high risk with and without cardio-protective agent dexrazoxane [HR + DEX and HR]). MFO, Fatmax and crossover point were not different between the groups (p = .078; p = .765; p = .726). Fatmax and crossover point were achieved at low exercise intensities. A higher MFO was achieved by men in the SR group (287.8 ± 111.2 mg/min) compared to those in HR + DEX (239.8 ± 97.0 mg/min) and HR groups (229.3 ± 98.9 mg/min) (p = .04). Childhood ALL survivors have low fat oxidation during exercise and oxidize carbohydrates at low exercise intensities, independently of the cumulative doses of doxorubicin they received. These findings alert clinicians on the long-term impact of cancer treatments on childhood ALL survivors' substrate oxidation.

Silencing of microRNA-106b-5p prevents doxorubicin-mediated cardiotoxicity through modulation of the PR55α/YY1/sST2 signaling axis

Clinical use of doxorubicin (Dox), an anthracycline with potent anti-tumor effects, is limited because of its highly chemotherapy-induced cardiotoxicity (CIC). After myocardial infarction (MI), we have recently identified Yin Yang-1 (YY1) and histone deacetylase 4 (HDAC4) as two factors involved in the overexpression of the isoform soluble suppression of tumorigenicity 2 (sST2) protein, which acts as a decoy receptor blocking the favorable effects of IL-33. Therefore, high levels of sST2 are associated with increased fibrosis, remodeling, and worse cardiovascular outcomes. No data exist on the role of the YY1/HDAC4/sST2 axis in CIC. This study aimed to evaluate the pathophysiological implication of the molecular YY1/HDAC4/sST2 axis in remodeling that is developed in patients treated with Dox as well as to suggest a novel molecular therapy to prevent anthracycline-induced cardiotoxicity. Here, we have characterized a novel nexus between miR106b-5p (miR-106b) levels and the YY1/HDAC4 axis in relation to the cardiac expression of sST2 using two experimental models with Dox-induced cardiotoxicity. The addition of Dox (5 μM) to human induced pluripotent stem cell-derived cardiomyocytes induced cellular apoptotic death via upregulation of miR-106b-5p (miR-106b), which was confirmed by specific mimic sequences. A functional blockage of miR-106b using the locked nucleic acid antagomir inhibited Dox-induced cardiotoxicity.

Cardio-oncology for Pediatric and Adolescent/Young Adult Patients

OPINION STATEMENT

As chemotherapy continues to improve the lives of patients with cancer, understanding the effects of these drugs on other organ systems, and the cardiovascular system in particular, has become increasingly important. The effects of chemotherapy on the cardiovascular system are a major determinant of morbidity and mortality in these survivors. Although echocardiography continues to be the most widely used modality for assessing cardiotoxicity, newer imaging modalities and biomarker concentrations may detect subclinical cardiotoxicity earlier. Dexrazoxane continues to be the most effective therapy for preventing anthracycline-induced cardiomyopathy. Neurohormonal modulating drugs have not prevented cardiotoxicity, so their widespread, long-term use for all patients is currently not recommended. Advanced cardiac therapies, including heart transplant, have been successful in cancer survivors with end-stage HF and should be considered for these patients. Research on new targets, especially genetic associations, may produce treatments that help reduce cardiovascular morbidity and mortality.

Modelling cardiac mechanics in doxorubicin-induced cardiotoxicity following childhood acute lymphoblastic leukemia using a combination of cardiac magnetic resonance imaging, cardiopulmonary exercise testing and the CircAdapt model

Children with acute lymphoblastic leukemia (ALL) are treated with doxorubicin-based chemotherapy that can lead to cardiotoxicity which is a well-known cause of mortality. This study aims to characterize myocardial subtle changes induced by doxorubicin-related cardiotoxicity. We used the combination of cardiac magnetic resonance (CMR) imaging, cardiopulmonary exercise testing and the CircAdapt model to explore hemodynamics and intraventricular mechanisms at rest and during exercise in 53 childhood ALL survivors. A sensitivity analysis of the CircAdapt model identified the most influencing parameters on the left ventricle volume. ANOVA were performed to explore significant differences between left ventricle stiffness, contractility, and arteriovenous pressure drop, as well as survivors' prognostic risk groups. No significant differences were observed between prognostic risk groups. The left ventricle stiffness and left ventricle contractility were non-significantly higher in survivors receiving cardioprotective agents (94.3 %), compared to those at standard and high prognostic risk (77 % and 86 %, respectively). In both left ventricle stiffness and left ventricle contractility, we observed that survivors receiving cardioprotective agents were close to the nominal value of CircAdapt (healthy reference group value is 100 %). This study allowed to improve our knowledge of potential subtle myocardial changes induced by doxorubicin-related cardiotoxicity in childhood ALL survivors. This study confirms that survivors exposed to a high cumulative dose of doxorubicin during treatments are at potential risk of myocardial changes many years after the end of their cancer, while cardio-protective agents may prevent changes in cardiac mechanical properties.

Pretreatment of 3-MA prevents doxorubicin-induced cardiotoxicity through inhibition of autophagy initiation

Anthracycline antineoplastics are effective in the treatment of hematological malignancies and solid tumors. However, the anthracycline-induced cardiotoxicity (AIC) limits their use as chemotherapeutic agents. Autophagy-based therapies have been explored to prevent AIC. Yet, whether inhibition of autophagy during its early stage could alleviate AIC remains unclear. In this study, we firstly observed the activation of autophagy during AIC in both cardiomyocyte cell lines AC16 and H9c2. Moreover, knockdown of Atg7, a key regulatory factor in early autophagy, could ameliorate the effects of DOX-induced AIC. Importantly, the use of early autophagy inhibitor 3-MA protected cardiomyocyte cells from DOX-induced cardiotoxicity in vitro and in a chronic AIC mouse model. Our findings demonstrate that inhibiting early stage of autophagy may be an effective preventative therapeutic strategy to protect cardiac function from AIC.

Loss of DNA repair mechanisms in cardiac myocytes induce dilated cardiomyopathy

Cardiomyopathy is a progressive disease of the myocardium leading to impaired contractility. Genotoxic cancer therapies are known to be potent drivers of cardiomyopathy, whereas causes of spontaneous disease remain unclear. To test the hypothesis that endogenous genotoxic stress contributes to cardiomyopathy, we deleted the DNA repair gene Ercc1 specifically in striated muscle using a floxed allele of Ercc1 and mice expressing Cre under control of the muscle-specific creatinine kinase (Ckmm) promoter or depleted systemically (Ercc1-/D mice). Ckmm-Cre+/- ;Ercc1-/fl mice expired suddenly of heart disease by 7 months of age. As young adults, the hearts of Ckmm-Cre+/- ;Ercc1-/fl mice were structurally and functionally normal, but by 6-months-of-age, there was significant ventricular dilation, wall thinning, interstitial fibrosis, and systolic dysfunction indicative of dilated cardiomyopathy. Cardiac tissue from the tissue-specific or systemic model showed increased apoptosis and cardiac myocytes from Ckmm-Cre+/- ;Ercc1-/fl mice were hypersensitive to genotoxins, resulting in apoptosis. p53 levels and target gene expression, including several antioxidants, were increased in cardiac tissue from Ckmm-Cre+/- ;Ercc1-/fl and Ercc1-/D mice. Despite this, cardiac tissue from older mutant mice showed evidence of increased oxidative stress. Genetic or pharmacologic inhibition of p53 attenuated apoptosis and improved disease markers. Similarly, overexpression of mitochondrial-targeted catalase improved disease markers. Together, these data support the conclusion that DNA damage produced endogenously can drive cardiac disease and does so mechanistically via chronic activation of p53 and increased oxidative stress, driving cardiac myocyte apoptosis, dilated cardiomyopathy, and sudden death.

Cardiac Imaging in Childhood Cancer Survivors: A State-of-the-Art Review

Childhood cancer survival has improved significantly in the past few decades, reaching rates of 80% or more at 5 years. However, with improved survival, early- and late-occurring complications of chemotherapy and radiotherapy exposure are becoming progressively more evident. Cardiovascular diseases represent the leading cause of non-oncological morbidity and mortality in this highly vulnerable population. Therefore, the necessity of reliable, noninvasive screening tools able to early identify cardiac complications early is now pre-eminent in order to implement prevention strategies and mitigate disease progression. Echocardiography, may allow identification of myocardial dysfunction, pericardial complications, and valvular heart diseases. However, additional imaging modalities may be necessary in selected cases. This manuscript provides an in-depth review of noninvasive imaging parameters studied in childhood cancer survivors. Furthermore, we will illustrate brief surveillance recommendations according to available evidence and future perspectives in this expanding field.

Cardiorespiratory Fitness and Cardiac Magnetic Resonance Imaging in Childhood Acute Lymphoblastic Leukemia Survivors

BACKGROUND

Childhood acute lymphoblastic leukemia survivors' anthracycline-induced cardiotoxicity could be prevented with good cardiorespiratory fitness levels and regular physical activity. This cross-sectional study aimed to assess the association between cardiorespiratory fitness and physical activity with cardiac magnetic resonance parameters.

METHODS

A total of 96 childhood acute lymphoblastic leukemia survivors underwent a maximal cardiopulmonary exercise test and answered physical activity questionnaires. We calculated the odds ratio of the preventive fraction of regular physical activity (≥150 min/wk) and adequate cardiorespiratory fitness levels (above the median ≥31.4 mL·kg-1·min-1) on cardiac magnetic resonance parameters (left ventricular [LV] and right ventricular [RV] morphological and functional parameters).

RESULTS

An adequate cardiorespiratory fitness was associated with a significant preventive fraction for LV (up to 84% for LV end-diastolic volume) and RV volumes (up to 88% for RV end-systolic volume). The adjusted analyses highlighted a preventive fraction of 36% to 91% between an adequate cardiorespiratory fitness and LV and RV parameters, late gadolinium enhancement fibrosis, and cardiac magnetic resonance relaxation times. No associations were reported with regular physical activity.

CONCLUSIONS

This study provides additional evidence regarding the benefits of an adequate cardiorespiratory fitness level for childhood cancer survivors' cardiac health.

Exposure to Doxorubicin Modulates the Cardiac Response to Isoproterenol in Male and Female Mice

Sex is a salient risk factor in the development of doxorubicin-induced cardiotoxicity. Sex differences in the heart's ability to respond to hypertrophic stimuli in doxorubicin-exposed animals have not been reported. We identified the sexual dimorphic effects of isoproterenol in mice pre-exposed to doxorubicin. Male and female intact or gonadectomized C57BL/6N mice underwent five weekly intraperitoneal injections of 4 mg/kg doxorubicin followed by a five-week recovery period. Fourteen days of subcutaneous isoproterenol injections (10 mg/kg/day) were administered after the recovery period. Echocardiography was used to assess heart function one and five weeks after the last doxorubicin injection and on the fourteenth day of isoproterenol treatment. Thereafter, mice were euthanized, and the hearts were weighed and processed for histopathology and gene expression analysis. Doxorubicin did not produce overt cardiac dysfunction in male or female mice before starting isoproterenol treatment. The chronotropic response to a single isoproterenol injection was blunted by doxorubicin, but the inotropic response was maintained in both males and females. Pre-exposure to doxorubicin caused cardiac atrophy in both control and isoproterenol-treated male mice but not in female mice. Counterintuitively, pre-exposure to doxorubicin abrogated isoproterenol-induced cardiac fibrosis. However, there were no sex differences in the expression of markers of pathological hypertrophy, fibrosis, or inflammation. Gonadectomy did not reverse the sexually dimorphic effects of doxorubicin. Additionally, pre-exposure to doxorubicin abrogated the hypertrophic response to isoproterenol in castrated male mice but not in ovariectomized female mice. Therefore, pre-exposure to doxorubicin caused male-specific cardiac atrophy that persisted after isoproterenol treatment, which could not be prevented by gonadectomy.

Apolipoprotein M Attenuates Anthracycline Cardiotoxicity and Lysosomal Injury

Apolipoprotein M (ApoM) binds sphingosine-1-phosphate (S1P) and is inversely associated with mortality in human heart failure (HF). Here, we show that anthracyclines such as doxorubicin (Dox) reduce circulating ApoM in mice and humans, that ApoM is inversely associated with mortality in patients with anthracycline-induced heart failure, and ApoM heterozygosity in mice increases Dox-induced mortality. In the setting of Dox stress, our studies suggest ApoM can help sustain myocardial autophagic flux in a post-transcriptional manner, attenuate Dox cardiotoxicity, and prevent lysosomal injury.

Heart Failure with Preserved Ejection Fraction in Children

Diastolic dysfunction (DD) refers to abnormalities in the mechanical function of the left ventricle (LV) during diastole. Severe LVDD can cause symptoms and the signs of heart failure (HF) in the setting of normal or near normal LV systolic function and is referred to as diastolic HF or HF with preserved ejection fraction (HFpEF). Pediatric cardiologists have long speculated HFpEF in children with congenital heart disease and cardiomyopathy. However, understanding the risk factors, clinical course, and validated biomarkers predictive of the outcome of HFpEF in children is challenging due to heterogeneous etiologies and overlapping pathophysiological mechanisms. The natural history of HFpEF varies depending upon the patient's age, sex, race, geographic location, nutritional status, biochemical risk factors, underlying heart disease, and genetic-environmental interaction, among other factors. Pediatric onset HFpEF is often not the same disease as in adults. Advances in the noninvasive evaluation of the LV diastolic function by strain, and strain rate analysis with speckle-tracking echocardiography, tissue Doppler imaging, and cardiac magnetic resonance imaging have increased our understanding of the HFpEF in children. This review addresses HFpEF in children and identifies knowledge gaps in the underlying etiologies, pathogenesis, diagnosis, and management, especially compared to adults with HFpEF.

Dexrazoxane Treatments Limits Subclinical Cardiac Dysfunction in Childhood Acute Lymphoblastic Leukemia Survivors Exposed to Doxorubicin Treatments

INTRODUCTION

Doxorubicin leads to dose dependent cardiotoxicity in childhood acute lymphoblastic leukemia (ALL) survivors. We investigated survivors' heart health using echocardiography and evaluated doxorubicin and dexrazoxane treatments on cardiac function.

METHODS

A total of 196 childhood ALL survivors were stratified (standard risk [SR], high risk with and without dexrazoxane (HR+DEX and HR). We performed a complete transthoracic echocardiographic assessment with M-mode echocardiography, Doppler, and Tissue Doppler. We used 2-dimensional and 3-dimensional echocardiography to measure the left ventricular ejection fraction, whereas myocardial strain imaging was used to obtain global strain indices.

RESULTS

Although most cardiac and arterial dimension parameters were not different between groups, a difference was observed in posterior intima of the right carotid ( P =0.017). Diastolic functions analyses reported that LV shortening fraction and left and right ventricular lateral S' wave amplitudes were lower in HR than in SR and HR+DEX groups ( P =0.028, P =0.048, and P =0.005, respectively). The LV lateral E' in diastolic function was lower in the HR than in SR and HR+DEX groups ( P =0.036). The LV end-systolic wall stress was higher in HR than in SR and HR+DEX groups ( P =0.009). A decrease contractility was observed, while the effect was not group specific. Strain rate was not different between groups, as opposed to tissue Doppler measurements.

CONCLUSIONS

This study showed that dexrazoxane treatments could limit subclinical cardiac dysfunction in childhood ALL survivors, whereas survivors in HR group who did not receive dexrazoxane had potential subclinical cardiac damage observable in heart failure patients. Echocardiographic screening for survivors must be part of the follow-up routine in cardio-oncology.

Diagnosis and Management of Cancer Treatment-Related Cardiac Dysfunction and Heart Failure in Children

It is disheartening for parents to discover that their children have long-term cardiac dysfunction after being cured of life-threatening childhood cancers. As the number of childhood cancer survivors increases, early and late oncology-therapy-related cardiovascular complications continues to rise. It is essential to understand that cardiotoxicity in childhood cancer survivors is persistent and progressive. A child's cancer experience extends throughout his lifetime, and ongoing care for long-term survivors is recognized as an essential part of the cancer care continuum. Initially, there was a lack of recognition of late cardiotoxicities related to cancer therapy. About 38 years ago, in 1984, pioneers like Dr. Lipshultz and others published anecdotal case reports of late cardiotoxicities in children and adolescents exposed to chemotherapy, including some who ended up with heart transplantation. At that time, cardiac tests for cancer survivors were denied by insurance companies because they did not meet appropriate use criteria. Since then, cardio-oncology has been an emerging field of cardiology that focuses on the early detection of cancer therapy-related cardiac dysfunction occurring during and after oncological treatment. The passionate pursuit of many healthcare professionals to make life better for childhood cancer survivors led to more than 10,000 peer-reviewed publications in the last 40 years. We synthesized the existing evidence-based practice and described our experiences in this review to share our current method of surveillance and management of cardiac dysfunction related to cancer therapy. This review aims to discuss the pathological basis of cancer therapy-related cardiac dysfunction and heart failure, how to stratify patients prone to cardiotoxicity by identifying modifiable risk factors, early detection of cardiac dysfunction, and prevention and management of heart failure during and after cancer therapy in children. We emphasize serial longitudinal follow-ups of childhood cancer survivors and targeted intervention for high-risk patients. We describe our experience with the new paradigm of cardio-oncology care, and collaboration between cardiologist and oncologist is needed to maximize cancer survival while minimizing late cardiotoxicity.

Intermediate molecular phenotypes to identify genetic markers of anthracycline-induced cardiotoxicity risk

Cardiotoxicity due to anthracyclines (CDA) affects cancer patients, but we cannot predict who may suffer from this complication. CDA is a complex disease whose polygenic component is mainly unidentified. We propose that levels of intermediate molecular phenotypes in the myocardium associated with histopathological damage could explain CDA susceptibility; so that variants of genes encoding these intermediate molecular phenotypes could identify patients susceptible to this complication. A genetically heterogeneous cohort of mice generated by backcrossing (N = 165) was treated with doxorubicin and docetaxel. Cardiac histopathological damage was measured by fibrosis and cardiomyocyte size by an Ariol slide scanner. We determine intramyocardial levels of intermediate molecular phenotypes of CDA associated with histopathological damage and quantitative trait loci (ipQTLs) linked to them. These ipQTLs seem to contribute to the missing heritability of CDA because they improve the heritability explained by QTL directly linked to CDA (cda-QTLs) through genetic models. Genes encoding these molecular subphenotypes were evaluated as genetic markers of CDA in three cancer patient cohorts (N = 517) whose cardiac damage was quantified by echocardiography or Cardiac Magnetic Resonance. Many SNPs associated with CDA were found using genetic models. LASSO multivariate regression identified two risk score models, one for pediatric cancer patients and the other for women with breast cancer. Molecular intermediate phenotypes associated with heart damage can identify genetic markers of CDA risk, thereby allowing a more personalized patient management. A similar strategy could be applied to identify genetic markers of other complex trait diseases.

Cardiovascular diseases in patients after hematopoietic stem cell transplantation: Systematic review and Meta-analysis

BACKGROUND

Hematopoietic Stem Cell Transplantation (HSCT), is performed to treat many malignancies such as autologous or allogenic. Despite the success of this method in treating patients, - sometimes some HSCT recipients face problems such as cardiovascular complications. Therefore, this systematic review and meta-analysis aimed to evaluate the prevalence of cardiovascular complications in post-transplant patients.

METHOD

In order to review the published studies, we examined PubMed, MEDLINE, Cochrane Library, Scopus, and web of science databases from the beginning to the end of January 2022, and we used tools by the Newcastle-Ottawa Scale to evaluate the quality of the studies.

RESULT

In this study, 37 articles were included in the meta-analysis and 30,957 patients were examined. Also, the mean age of patients was 35.37 years. Based on the results of the meta-analysis, the prevalence of cardiovascular disease (CVD), was 16.84%. In addition, other complications related to CVD which include Arrhythmias, Congestive Heart Failure (CHF), Hypertension, stroke, and mortality were examined in patients who had hematopoietic stem cell transplantation and the resulting amounts were 3.91%, 3.66, 17.71, 0.22%, and 1.53%, respectively.

CONCLUSION

This study showed that the prevalence of cardiovascular disease after hematopoietic stem cell transplantation is high and needs special attention.

Pharmacogenetics of chemotherapy treatment response and -toxicities in patients with osteosarcoma: a systematic review

BACKGROUND

Osteosarcoma is the most common bone tumor in children and adolescents. Despite multiagent chemotherapy, only 71% of patients survives and these survivors often experience long-term toxicities. The main objective of this systematic review is to provide an overview of the discovery of novel associations of germline polymorphisms with treatment response and/or chemotherapy-induced toxicities in osteosarcoma.  METHODS: MEDLINE and Embase were systematically searched (2010-July 2022). Genetic association studies were included if they assessed > 10 germline genetic variants in > 5 genes in relevant drug pathways or if they used a genotyping array or other large-scale genetic analysis. Quality was assessed using adjusted STrengthening the REporting of Genetic Association studies (STREGA)-guidelines. To find additional evidence for the identified associations, literature was searched to identify replication studies.

RESULTS

After screening 1999 articles, twenty articles met our inclusion criteria. These range from studies focusing on genes in relevant pharmacokinetic pathways to whole genome sequencing. Eleven articles reported on doxorubicin-induced cardiomyopathy. For seven genetic variants in CELF4, GPR35, HAS3, RARG, SLC22A17, SLC22A7 and SLC28A3, replication studies were performed, however without consistent results. Ototoxicity was investigated in one study. Five small studies reported on mucosistis or bone marrow, nephro- and/or hepatotoxicity. Six studies included analysis for treatment efficacy. Genetic variants in ABCC3, ABCC5, FasL, GLDC, GSTP1 were replicated in studies using heterogeneous efficacy outcomes.

CONCLUSIONS

Despite that results are promising, the majority of associations were poorly reproducible due to small patient cohorts. For the future, hypothesis-generating studies in large patient cohorts will be necessary, especially for cisplatin-induced ototoxicity as these are largely lacking. In order to form large patient cohorts, national and international collaboration will be essential.

MicroRNA composition of plasma extracellular vesicles: a harbinger of late cardiotoxicity of doxorubicin

BACKGROUND

The use of doxorubicin is associated with an increased risk of acute and long-term cardiomyopathy. Despite the constantly growing number of cancer survivors, little is known about the transcriptional mechanisms which progress in the time leading to a severe cardiac outcome. It is also unclear whether long-term transcriptomic alterations related to doxorubicin use are similar to transcriptomic patterns present in patients suffering from other cardiomyopathies.

METHODS

We have sequenced miRNA from total plasma and extracellular vesicles (EVs) from 66 acute lymphoblastic leukemia (ALL) survivors and 61 healthy controls (254 samples in total). We then analyzed processes regulated by differentially expressed circulating miRNAs and cross-validated results with the data of patients with clinically manifested cardiomyopathies.

RESULTS

We found that especially miRNAs contained within EVs may be informative in terms of cardiomyopathy development and may regulate pathways related to neurotrophin signaling, transforming growth factor beta (TGFβ) or epidermal growth factor receptors (ErbB). We identified vesicular miR-144-3p and miR-423-3p as the most variable between groups and significantly correlated with echocardiographic parameters and, respectively, for plasma: let-7g-5p and miR-16-2-3p. Moreover, vesicular miR-144-3p correlates with the highest number of echocardiographic parameters and is differentially expressed in the circulation of patients with dilated cardiomyopathy. We also found that distribution of particular miRNAs between of plasma and EVs (proportion between compartments) e.g., miR-184 in ALL, is altered, suggesting changes within secretory and miRNA sorting mechanisms.

CONCLUSIONS

Our results show that transcriptomic changes resulting from doxorubicin induced myocardial injury are reflected in circulating miRNA levels and precede development of the late onset cardiomyopathy phenotype. Among miRNAs related to cardiac function, we found vesicular miR-144-3p and miR-423-3p, as well as let-7g-5p and miR-16-2-3p contained in the total plasma. Selection of source for such studies (plasma or EVs) is of critical importance, as distribution of some miRNA between plasma and EVs is altered in ALL survivors, in comparison to healthy people, which suggests that doxorubicin-induced changes include miRNA sorting and export to extracellular space.

Protective Effects of Hippophae rhamnoides L. Phenylpropanoids on Doxorubicin-Induced Cardiotoxicity in Zebrafish

Hippophae rhamnoides L. is a deciduous shrub that contains many unique bioactive substances. This sea buckthorn possesses anticancer, antioxidant, anti-inflammatory, and cardiovascular protective properties. Herein, the effects of phenylpropyl compounds extracted from H. rhamnoides L. on doxorubicin (Dox)-induced cardiotoxicity were evaluated in zebrafish. Cardiac injury in zebrafish was induced using 35 μM Dox for 96 h, and 30 μM phenylpropanoid compounds were used as the protective treatment. The cardioprotective effects and mechanisms of the four phenylpropanoids were investigated using microscopy, behavioral analysis, acridine orange staining, western blotting, flow cytometry, and real-time quantitative polymerase chain reaction. The extracted phenylpropanoids could significantly relieve Dox-induced cardiac injury in zebrafish and inhibit cardiomyocyte apoptosis. The mechanisms of action were mainly related to the stability of mitochondrial biogenesis and function maintained by phenylpropanoids in zebrafish. To our knowledge, this is the first report on the protective effect of sea buckthorn against myocardial injury in zebrafish. Our findings provide support for the further research and development of sea buckthorn and its components.

Cardiovascular Risk in Childhood Cancer Survivors

Cancer is a prominent cause of death worldwide in the pediatric population. Since childhood cancer is not possible to prevent, it is essential to focus on a prompt and correct diagnosis followed by effective, evidence-based therapy with individualized supportive care. Given the enhancement of childhood cancer management over the past decades, survival rate has significantly improved, thus leading to the progression of several late effects, including metabolic derangements. These metabolic imbalances are associated with the underlying disease and the cancer treatments. As a result, the metabolic state may contribute to a high risk of cardiovascular morbidity and premature mortality among childhood cancer survivors. This review aims to summarize the potential pathophysiological mechanisms linked to the risk of diabetes and metabolic syndrome and screening recommendations. Further investigations are needed to clarify the underlying mechanisms of such metabolic abnormalities and to improve long-term cardiometabolic survival among these patients.

Cardiovascular outcomes of patients treated for non-Hodgkin lymphoma with first-line doxorubicin-based chemotherapy

We conducted a single-center retrospective study to assess cardiovascular (CV) toxicity and treatment discontinuation for CV toxicity in diffuse large B-cell lymphoma (DLBCL) or follicular lymphoma (FL) patients treated with immunochemotherapy (R-CHOP-like). Between 2006 and 2017, 433 patients were included (DLBCL: n = 345, FL: n = 88). The median age was 63 years (50-73). We defined three types of CV toxicity: early-onset cardiovascular toxicity (the event occurred within 6 months following treatment start); subacute toxicity (the event occurred between 6 months and 1 year after treatment start) and late toxicity (the event occurred 1 year or more after treatment start). Forty-eight (11.1%) patients experienced at least one anthracycline-related CV event. Seven patients experienced treatment discontinuation due to CV toxicity. Early-onset and subacute cardiac events were primarily acute heart failure (34.3%) and atrial fibrillation (28.6%). History of ischemic heart disease (p = 0.02) and valvular heart disease (p = 0.03) were associated with a higher risk of anthracycline-related CV event occurrence.

Chemotherapy-induced peripheral neuropathy in children and adolescent cancer patients

Brain cancer and leukemia are the most common cancers diagnosed in the pediatric population and are often treated with lifesaving chemotherapy. However, chemotherapy causes severe adverse effects and chemotherapy-induced peripheral neuropathy (CIPN) is a major dose-limiting and debilitating side effect. CIPN can greatly impair quality of life and increases morbidity of pediatric patients with cancer, with the accompanying symptoms frequently remaining underdiagnosed. Little is known about the incidence of CIPN, its impact on the pediatric population, and the underlying pathophysiological mechanisms, as most existing information stems from studies in animal models or adult cancer patients. Herein, we aim to provide an understanding of CIPN in the pediatric population and focus on the 6 main substance groups that frequently cause CIPN, namely the vinca alkaloids (vincristine), platinum-based antineoplastics (cisplatin, carboplatin and oxaliplatin), taxanes (paclitaxel and docetaxel), epothilones (ixabepilone), proteasome inhibitors (bortezomib) and immunomodulatory drugs (thalidomide). We discuss the clinical manifestations, assessments and diagnostic tools, as well as risk factors, pathophysiological processes and current pharmacological and non-pharmacological approaches for the prevention and treatment of CIPN.

Macrophage, a potential targeted therapeutic immune cell for cardiomyopathy

Cardiomyopathy is a major cause of heart failure, leading to systolic and diastolic dysfunction and promoting adverse cardiac remodeling. Macrophages, as key immune cells of the heart, play a crucial role in inflammation and fibrosis. Moreover, exogenous and cardiac resident macrophages are functionally and phenotypically different during cardiac injury. Although experimental evidence has shown that macrophage-targeted therapy is promising in cardiomyopathy, clinical translation remains challenging. In this article, the molecular mechanism of macrophages in cardiomyopathy has been discussed in detail based on existing literature. The issues and considerations of clinical treatment strategies for myocardial fibrosis has also been analyzed.

Deterioration in myocardial work indices precedes changes in global longitudinal strain following anthracycline chemotherapy

BACKGROUND

Left ventricular ejection fraction (LVEF) and global longitudinal strain (GLS) have conventionally been used for surveillance of cardiac function after cancer therapy, but indices of myocardial work (MW) are potentially superior for this purpose because they take into account both myocardial deformation and loading conditions.

OBJECTIVES

We aimed to investigate the usefulness of MW in the follow-up of children and young adults following anthracycline chemotherapy.

METHODS

Conventional markers of LV function (LV fractional shortening [LVFS], LVEF, GLS) and MW indices (global work index [GWI], global constructive work [GCW], global wasted work [GWW], and global work efficiency [GWE]) were obtained from 2342 echocardiographic examinations in 598 patients (354 male, 12.2 [4.7-17.3] years at initiation of chemotherapy).

RESULTS

GWI, GCW, GLS, LVFS, and LVEF all deteriorated significantly during and after anthracycline chemotherapy, while GWW decreased and GWE was preserved. On multivariable analysis, MW indices were correlated with conventional markers of LV function and with clinical information relating to underlying malignancy and chemotherapy. Cox regression analysis revealed that similar levels of deterioration in GWW, GWI, and GCW preceded those in GLS, LFS, and LVEF.

CONCLUSIONS

Non-invasive MW indices correlate well with conventional markers of LV function. Indices of MW appear to provide an earlier and more sensitive marker of progression towards chemotherapy-related cardiac dysfunction. Future studies are warranted to validate whether the incorporation of non-invasive MW into the routine clinical surveillance in patients after chemotherapy would improve outcomes.