Radiation-Induced Cardiovascular Disease: Mechanisms and Importance of Linear Energy Transfer

Health Effects of Occupational and Environmental Exposures to Nuclear Power Plants: A Meta-Analysis and Meta-Regression

PURPOSE OF REVIEW

Numerous epidemiological studies have shown increased health risks among workers and residents living near nuclear power plants exposed to radiation levels meeting regulatory dose limits. This study aimed to evaluate the association between radiation exposure and disease risks among these populations exposed to radiation levels meeting the current regulatory dose limits.

RECENT FINDINGS

We searched four databases (Cochrane Library, PubMed, ScienceDirect, and Web of Science) for studies published before August 2023, screened eligible studies (inclusion and exclusion criteria based on population, exposure, comparator, and outcome framework), and collected data on exposure indicators and disease risks. We applied random-effects models of meta-analysis to estimate the pooled effects and meta-regression to assess the dose-response relationship (radiation dose rate for workers and distance for residents). We identified 47 studies, 13 with worker and 34 with resident samples, covering 175 nuclear power plants from 17 countries, encompassing samples of 480,623 workers and 7,530,886 residents. Workers had a significantly lower risk for all-cancer and a significantly higher risk for mesothelioma. Residents had significantly higher risks for all-cancer, thyroid cancer, and leukemia. Notably, children under 5 years old showed the highest risk for all-cancer. Our meta-regression showed a significantly positive dose-response relationship between cumulative dose of radiation exposure and risk for circulatory disease among workers. Our findings demonstrated higher risks for mesothelioma for workers and all-cancer, thyroid cancer, and leukemia for residents exposed to low-dose radiation from nuclear power plants. Some included studies did not adjust for cancer risk confounders, which could overestimate the association between radiation exposure and cancer risk and increase the risk of bias.

Comparative Cardiovascular Risks of Radical Prostatectomy and External Beam Radiation Therapy in Early-Stage Prostate Cancer: A Comprehensive Retrospective Analysis

BACKGROUND

The risk of cardiac disease mortality has recently become a focal point of concern within the medical community for patients with prostate cancer (PCa). Given that radical prostatectomy (RP) and external beam radiation therapy (EBRT) are the main treatment modalities for localized PCa, their specific impact on cardiovascular-specific mortality (CSM) remains unclear. This study explored the specific effects of RP and EBRT on CSM risk to guide clinical treatment decisions.

METHODS

Data from patients aged 45-74 years, who were diagnosed with T1-2N0M0 stage PCa from the SEER database (2010-2015), were used. Multivariate statistical methods, including propensity score matching (PSM), competing risk regression, COX regression analysis, and Fine-Gray testing, were applied to assess the impact of RP and EBRT on CSM risk.

RESULTS

Among 146,082 T1-2 stage PCa patients, cardiac disease emerged as the primary cause of death, surpassing PCa itself. Multifactorial COX regression and competing risk regression analyses indicated that local treatments do not increase CSM risk. Further analysis revealed a significant increase in CSM risk for patients undergoing only EBRT compared with those undergoing only RP (hazard ratio [HR]  = 2.71, 95% confidence interval [CI] 1.96-3.74, P < 0.001), with subsequent PSM adjustment, further confirming a significantly reduced risk in the RP treatment group (HR 0.23, 95% CI 0.13-0.40, P < 0.001).

CONCLUSIONS

T1-2 stage PCa patients face a significant risk of CSM, with RP offering a potential advantage over EBRT in reducing this risk. These findings encourage clinicians to comprehensively consider the potential impact on cardiac health when formulating treatment plans, providing crucial guidance for optimizing treatment strategies.

Space research to explore novel biochemical insights on Earth

Travel to space has overcome unprecedent technological challenges and this has resulted in transfer of these technological results on Earth to better our lives. Health technology, medical devices, and research advancements in human biology are the first beneficiaries of this transfer. The real breakthrough came with the International Space Station, which endorsed multidisciplinary international scientific collaborations and boosted the research on pathophysiological adaptation of astronauts to life on space. These studies evidenced that life in space appeared to have exposed the astronauts to an accelerated aging-related pathophysiological dysregulation across multiple systems. In this review we emphasize the interaction between several biomarkers and their alteration in concentrations/expression/function by space stress factors. These altered interactions, suggest that different biochemical and hormonal factors, and cell signals, contribute to a complex network of pathophysiological mechanisms, orchestrating the homeostatic dysregulation of various organs/metabolic pathways. The main effects of space travel on altering cell organelles biology, ultrastructure, and cross-talk, have been observed in cell aging as well as in the disruption of metabolic pathways, which are also the causal factor of rare inherited metabolic disorders, one of the major pediatric health issue. The pathophysiologic breakthrough from space research could allow the development of precision health both on Earth and Space by promoting the validation of improved biomarker-based risk scores and the exploration of new pathophysiologic hypotheses and therapeutic targets. Nonstandard abbreviations: International Space Station (ISS), Artificial Intelligence (AI), European Space Agency (ESA), National Aeronautics and Space Agency (NASA), Low Earth Orbit (LEO), high sensitive troponin (hs-cTn), high sensitive troponin I (hs-cTn I), high sensitive troponin T, Brain Natriuretic Peptide (BNP), N terminal Brain Natriuretic Peptide (NT-BNP), cardiovascular disease (CVD), parathyroid hormone (PTH), urinary hydroxyproline (uHP), urinary C- and N-terminal telopeptides (uCTX and uNTX), pyridinoline (PYD), deoxypyridinoline (DPD), half-time (HF), serum Bone Alkaline Phosphatase (sBSAP), serum Alkaline Phosphatase (sAP), Carboxy-terminal Propeptide of Type 1 Procollagen (P1CP), serum Osteocalcin (sOC)), advanced glycation end products (AGEs), glycated hemoglobin A1c (HbA1c), Insulin-like growth factor 1 (IGF1), Growth Hormone (GH), amino acid (AA), β-hydroxy-β methyl butyrate (HMB), maple syrup urine disease (MSUD), non-communicable diseases (NCDs).

Factors Influencing Effects of Low-dose Radiation Exposure

ABSTRACT

It is now well accepted that the mechanisms induced by low-dose exposures to ionizing radiation (LDR) are different from those occurring after high-dose exposures. However, the downstream effects of these mechanisms are unclear as are the quantitative relationships between exposure, effect, harm, and risk. In this paper, we will discuss the mechanisms known to be important with an overall emphasis on how so-called "non-targeted effects" (NTE) communicate and coordinate responses to LDR. Targeted deposition of ionizing radiation energy in cells causing DNA damage is still regarded as the dominant trigger leading to all downstream events whether targeted or non-targeted. We regard this as an over-simplification dating back to formal target theory. It ignores that last 100 y of biological research into stress responses and signaling mechanisms in organisms exposed to toxic substances, including ionizing radiation. We will provide evidence for situations where energy deposition in cellular targets alone cannot be plausible as a mechanism for LDR effects. An example is where the energy deposition takes place in an organism not receiving the radiation dose. We will also discuss how effects after LDR depend more on dose rate and radiation quality rather than actual dose, which appears rather irrelevant. Finally, we will use recent evidence from studies of cataract and melanoma induction to suggest that after LDR, post-translational effects, such as protein misfolding or defects in energy metabolism or mitochondrial function, may dominate the etiology and progression of the disease. A focus on such novel pathways may open the way to successful prophylaxis and development of new biomarkers for better risk assessment after low dose exposures.

Approaches for reducing chemo/radiation-induced cardiotoxicity by nanoparticles

Nanoparticles are fascinating and encouraging carriers for cancer treatment due to their extraordinary properties and potential applications in targeted drug delivery, treatment, and diagnosis. Experimental studies including in vitro and in vivo examinations show that nanoparticles can cause a revolution in different aspects of cancer therapy. Normal tissue toxicity and early and late consequences are the major limitations of cancer therapy by radiotherapy and chemotherapy. However, the delivery of drugs into tumors or reducing the accumulation of drugs in normal tissues can permit a more satisfactory response of malignancies to therapy with more inferior side effects. Cardiac toxicity is one of the major problems for chemotherapy and radiotherapy. Therefore, several experimental studies have been performed to minimize the degenerative impacts of cancer treatment on the heart and also enhance the influences of radiotherapy and chemotherapy agents in cancers. This review article emphasizes the benefits of nanoparticle-based drug delivery techniques, including minimizing the exposure of the heart to anticancer drugs, enhancing the accumulation of drugs in cancers, and expanding the effectiveness of radiotherapy. The article also discusses the challenges and problems accompanied with nanoparticle-based drug delivery techniques such as toxicity, which need to be addressed through further research. Moreover, the article emphasizes the importance of developing safe and effective nanoparticle-based therapies that can be translated into clinical practice.

Therapeutic strategies based on non-ionizing radiation to prevent venous neointimal hyperplasia: the relevance for stenosed arteriovenous fistula, and the role of vascular compliance

We have reviewed the development and current status of therapies based on exposure to non-ionizing radiation (with a photon energy less than 10 eV) aimed at suppressing the venous neointimal hyperplasia, and consequentially at avoiding stenosis in arteriovenous grafts. Due to the drawbacks associated with the medical use of ionizing radiation, prominently the radiation-induced cardiovascular disease, the availability of procedures using non-ionizing radiation is becoming a noteworthy objective for the current research. Further, the focus of the review was the use of such procedures for improving the vascular access function and assuring the clinical success of arteriovenous fistulae in hemodialysis patients. Following a brief discussion of the physical principles underlying radiotherapy, the current methods based on non-ionizing radiation, either in use or under development, were described in detail. There are currently five such techniques, including photodynamic therapy (PDT), far-infrared therapy, photochemical tissue passivation (PTP), Alucent vascular scaffolding, and adventitial photocrosslinking. The last three are contingent on the mechanical stiffening achievable by the exogenous photochemical crosslinking of tissular collagen, a process that leads to the decrease of venous compliance. As there are conflicting opinions on the role of compliance mismatch between arterial and venous conduits in a graft, this aspect was also considered in our review.

Association of radioactive iodine treatment in differentiated thyroid cancer and cardiovascular death: a large population-based study

PURPOSE

The risk of cardiovascular diseases' death (CVD) in patients with differentiated thyroid cancer (DTC) treated with radioactive iodine (RAI) after surgery has not been adequately studied.

METHODS

Data of DTC patients who received RAI after surgery were retrieved from the Surveillance, Epidemiology, and End Result (SEER) database (2004-2015). Standardized mortality rate (SMR) analysis was used to evaluate the CVD risk in patients with RAI vs general population. A 1:1 propensity score matching (PSM) was applied to balance inter-group bias, and Pearson's correlation coefficient was used to detect collinearity between variables. The Cox proportional hazard model and multivariate competing risk model were utilized to evaluate the impact of RAI on CVD. At last, we curved forest plots to compare differences in factors significantly associated with CVD or cancer-related deaths.

RESULTS

DTC patients with RAI treatment showed lower SMR for CVD than general population (RAI: SMR = 0.66, 95% CI 0.62-0.71, P < 0.05). After PSM, Cox proportional hazard regression demonstrated a decreased risk of CVD among patients with RAI compared to patients without (HR = 0.76, 95% CI 0.6-0.97, P = 0.029). However, in competing risk regression analysis, there was no significant difference (adjusted HR = 0.82, 95% CI 0.66-1.01, P = 0.11). The independent risk factors associated with CVD were different from those associated with cancer-related deaths.

CONCLUSION

The CVD risk between DTC patients treated with RAI and those who did not was no statistical difference. Noteworthy, they had decreased CVD risk compared with the general population.

Carotid endarterectomy for the management of carotid stenosis occurring concurrently with head and neck cancer

PURPOSE OF REVIEW

Currently, most patients with concurrent head and neck cancer (HNC) and carotid stenosis (CS) are treated disjointedly for their oncologic and vascular lesions. The purpose of this review is to evaluate literature exploring a novel approach to these cases that poses several advantages, in which carotid endarterectomy (CEA) is performed simultaneously with surgical resection of HNC.

RECENT FINDINGS

Carotid stenosis is a common comorbidity of patients presenting with head and neck cancer as these pathologies have overlapping risk factors. Adjuvant oncologic therapy such as radiation therapy to the site of the lesion is known to increase development or progression of carotid stenosis. Performing simultaneous surgical management of CS and HNC decreases total procedures for the patient, provides a less challenging surgical field, and eliminates prioritization of treatment initiation for one pathology over the other. There has been limited reporting of simultaneous CEA with oncologic resection of HNC in the literature. However, of the 21 cases reviewed here, no perioperative strokes were reported with only one perioperative death from myocardial infarction.

SUMMARY

Available literature supports that simultaneous CEA with oncologic resection of HNC is safe and may offer several advantages, although larger studies are required.

Profound DNA methylomic differences between single- and multi-fraction alpha irradiations of lung fibroblasts

BACKGROUND

Alpha (α)-radiation is a ubiquitous environmental agent with epigenotoxic effects. Human exposure to α-radiation at potentially harmful levels can occur repetitively over the long term via inhalation of naturally occurring radon gas that accumulates in enclosed spaces, or as a result of a single exposure from a nuclear accident. Alterations in epigenetic DNA methylation (DNAm) have been implicated in normal aging and cancer pathogenesis. Nevertheless, the effects of aberrations in the methylome of human lung cells following exposure to single or multiple α-irradiation events on these processes remain unexplored.

RESULTS

We performed genome-wide DNAm profiling of human embryonic lung fibroblasts from control and irradiated cells using americium-241 α-sources. Cells were α-irradiated in quadruplicates to seven doses using two exposure regimens, a single-fraction (SF) where the total dose was given at once, and a multi-fraction (MF) method, where the total dose was equally distributed over 14 consecutive days. Our results revealed that SF irradiations were prone to a decrease in DNAm levels, while MF irradiations mostly increased DNAm. The analysis also showed that the gene body (i.e., exons and introns) was the region most altered by both the SF hypomethylation and the MF hypermethylation. Additionally, the MF irradiations induced the highest number of differentially methylated regions in genes associated with DNAm biomarkers of aging, carcinogenesis, and cardiovascular disease. The DNAm profile of the oncogenes and tumor suppressor genes suggests that the fibroblasts manifested a defensive response to the MF α-irradiation. Key DNAm events of ionizing radiation exposure, including changes in methylation levels in mitochondria dysfunction-related genes, were mainly identified in the MF groups. However, these alterations were under-represented, indicating that the mitochondria undergo adaptive mechanisms, aside from DNAm, in response to radiation-induced oxidative stress.

CONCLUSIONS

We identified a contrasting methylomic profile in the lung fibroblasts α-irradiated to SF compared with MF exposures. These findings demonstrate that the methylome response of the lung cells to α-radiation is highly dependent on both the total dose and the exposure regimen. They also provide novel insights into potential biomarkers of α-radiation, which may contribute to the development of innovative approaches to detect, prevent, and treat α-particle-related diseases.

Reduction in Primary Operator Radiation Dose Exposure During Coronary Angioplasty Using Radiation Absorbing Drape

Background Percutaneous coronary intervention (PCI) involves the use of ionizing radiation and is a common procedure in a cardiac catheterization suite. The RADPAD® surgical drape (Worldwide Innovations & Technologies, Inc., Lenexa, KS) has been developed to reduce scatter radiation exposure to primary operators during routine PCI procedures. This study aims to assess the efficacy of RADPAD drapes in reducing radiation dose in the catheterization laboratory. Methods This was a single-center, prospective, observational study that aimed to compare the primary operator dose received with and without the use of a commercially available shield (RADPAD) during PCI. A total of 53 consecutive patients undergoing PCI were randomized in a 1:1 pattern to receive either the RADPAD (study group) or no RADPAD (control group). Standard shielding and personal protective equipment were used. Radiation exposure to the primary operator, total fluoroscopy time, number of cine acquisitions, and air kerma were recorded for each procedure. A one-way ANOVA calculator, including the Tukey honestly significant difference (HSD) test, was used to compare the mean values of radiation exposure. Scatterplot analysis and linear regression slopes of dose relative to air kerma were performed. All shields were reused once only. Results The study compared radiation exposure during PCI procedures between patients who received radiation attenuation devices (RADPAD) and those who did not. The RADPAD group had 30 patients, while the NO RADPAD group had 23 patients. There was a significant difference in the number of coronary angiography and single/multi-vessel PCI procedures between the two groups. There was no significant difference in procedural time or air kerma dose between the groups, but the RADPAD group had a significantly lower radiation dose (mean dose of 3.679 mrem) compared to the NO RADPAD group (mean dose of 8.12 mrem) (p < 0.00001). The primary operator dose per unit of air kerma was also significantly lower in the RADPAD group. Overall, the use of RADPAD resulted in a significant reduction in radiation exposure during PCI procedures. Conclusion The present study provides further evidence for the efficacy of using radiation-absorbing drapes (RADPAD) in reducing primary operator radiation dose exposure during coronary angioplasty. The equipment for radiation dose reduction of patients also reduces the radiation dose of medical staff. Therefore, the use of RADPAD is recommended as a safe and effective measure for reducing operator radiation dose exposure during coronary angioplasty.

Radiation-Induced Peripheral Artery Disease in a 63-Year-Old Patient

Tobacco use, hypertension, diabetes, and hypercholesterolemia are known risk factors for peripheral artery disease (PAD). However, additional causes of PAD, such as radiation therapy, should be considered for the prevention and diagnosis of this disease. The patient described in this report had 36 radiation therapies directly to the pelvis and bladder area due to bladder cancer. The presence of severe PAD on this patient's right external iliac artery, the same area where he received radiation therapy, raises the question of whether radiation therapy contributed to the development of PAD. In addition, his history of anal intraepithelial neoplasia, obstructive uropathy, and chronic kidney disease further demonstrated that he possibly suffered extensive tissue damage due to radiation to the pelvis. This case report explores the current diagnosis guidelines and treatment options for patients with radiation-induced PAD. Through this case study, we aim to bring awareness to this lesser-known cause of PAD among medical providers and promote research for the prevention and treatment of this disease.

Assessment of short-term effects of thoracic radiotherapy on the cardiovascular parasympathetic and sympathetic nervous systems

Background

Prior research suggests that cardiovascular autonomic dysfunction might be an early marker of cardiotoxicity induced by antitumor treatment and act as an early predictor of cardiovascular disease-related morbidity and mortality. The impact of thoracic radiotherapy on the parasympathetic and sympathetic nervous systems, however, remains unclear. Therefore, this study aimed to evaluate the short-term effects of thoracic radiotherapy on the autonomic nervous system, using deceleration capacity (DC), acceleration capacity (AC) of heart rate, and heart rate variability (HRV) as assessment tools.

Methods

A 5 min electrocardiogram was collected from 58 thoracic cancer patients before and after thoracic radiotherapy for DC, AC, and HRV analysis. HRV parameters employed included the standard deviation of the normal-normal interval (SDNN), root mean square of successive interval differences (RMSSD), low frequency power (LF), high frequency power (HF), total power (TP), and the LF to HF ratio. Some patients also received systemic therapies alongside radiotherapy; thus, patients were subdivided into a radiotherapy-only group (28 cases) and a combined radiotherapy and systemic therapies group (30 cases) for additional subgroup analysis.

Results

Thoracic radiotherapy resulted in a significant reduction in DC (8.5 [5.0, 14.2] vs. 5.3 [3.5, 9.4], p = 0.002) and HRV parameters SDNN (9.9 [7.03, 16.0] vs. 8.2 [6.0, 12.4], p = 0.003), RMSSD (9.9 [6.9, 17.5] vs. 7.7 [4.8, 14.3], p = 0.009), LF (29 [10, 135] vs. 24 [15, 50], p = 0.005), HF (35 [12, 101] vs. 16 [9, 46], p = 0.002), TP (74 [41, 273] vs. 50 [33, 118], p < 0.001), and a significant increase in AC (-8.2 [-14.8, -4.9] vs. -5.8 [-10.1, -3.3], p = 0.003) and mean heart rate (79.8 ± 12.6 vs. 83.9 ± 13.6, p = 0.010). Subgroup analysis indicated similar trends in mean heart rate, DC, AC, and HRV parameters (SDNN, RMSSD, LF, HF, TP) in both the radiotherapy group and the combined treatment group post-radiotherapy. No statistically significant difference was noted in the changes observed in DC, AC, and HRV between the two groups pre- and post-radiotherapy.

Conclusion

Thoracic radiotherapy may induce cardiovascular autonomic dysfunction by reducing parasympathetic activity and enhancing sympathetic activity. Importantly, the study found that the concurrent use of systemic therapies did not significantly amplify or contribute to the alterations in autonomic function in the short-term following thoracic radiotherapy. DC, AC and HRV are promising and feasible biomarkers for evaluating autonomic dysfunction caused by thoracic radiotherapy.

An integrative review of nonobvious puzzles of cellular and molecular cardiooncology

Oncologic patients are subjected to four major treatment types: surgery, radiotherapy, chemotherapy, and immunotherapy. All nonsurgical forms of cancer management are known to potentially violate the structural and functional integrity of the cardiovascular system. The prevalence and severity of cardiotoxicity and vascular abnormalities led to the emergence of a clinical subdiscipline, called cardiooncology. This relatively new, but rapidly expanding area of knowledge, primarily focuses on clinical observations linking the adverse effects of cancer therapy with deteriorated quality of life of cancer survivors and their increased morbidity and mortality. Cellular and molecular determinants of these relations are far less understood, mainly because of several unsolved paths and contradicting findings in the literature. In this article, we provide a comprehensive view of the cellular and molecular etiology of cardiooncology. We pay particular attention to various intracellular processes that arise in cardiomyocytes, vascular endothelial cells, and smooth muscle cells treated in experimentally-controlled conditions in vitro and in vivo with ionizing radiation and drugs representing diverse modes of anti-cancer activity.

Outcomes of Radioactive Iodine Versus Surgery for the Treatment of Graves’ Disease: a Systematic Review and Meta-analysis

Graves’ disease (GD) is a systemic autoimmune disorder mainly affecting the thyroid gland. During GD management, the principal target is to control the hyperthyroid state. There have been three rather similarly effective modalities: medical therapy with antithyroid drugs (ATD), radioactive iodine (RAI), or surgical excision of the thyroid tissue (thyroidectomy). Defining the relative risks and benefits of each of the two potential definitive treatment options (RAI or thyroidectomy) is crucial for creating evidence-based therapy algorithms. This systematic review and meta-analysis aimed to compare the outcomes of these two treatment options. This is a systematic review and meta-analysis that analyzed the studies comparing RAI and thyroidectomy to treat GD. Studies were obtained by searching on Scopus, the Cochrane Central Register of Controlled Trials, and PubMed central database. The surgically treated group showed significantly lower failure rates, non-significantly lower cardiovascular morbidities, non-significantly higher complication rates, and significantly lower mortality rates. The RAI-related complications were mostly the development or worsening of Graves’ ophthalmopathy. This review and meta-analysis comparing surgery and radioactive iodine for the treatment of Grave’s disease from 16 well-conducted trials has shown that although surgery viz., total thyroidectomy was less frequently utilized for the treatment of Grave’s disease, it controlled the symptoms with greater success and without any worsening of Grave’s ophthalmopathy.

Atherogenic potential of microgravity hemodynamics in the carotid bifurcation: a numerical investigation

Long-duration spaceflight poses multiple hazards to human health, including physiological changes associated with microgravity. The hemodynamic adaptations occurring upon entry into weightlessness have been associated with retrograde stagnant flow conditions and thromboembolic events in the venous vasculature but the impact of microgravity on cerebral arterial hemodynamics and function remains poorly understood. The objective of this study was to quantify the effects of microgravity on hemodynamics and wall shear stress (WSS) characteristics in 16 carotid bifurcation geometries reconstructed from ultrasonography images using computational fluid dynamics modeling. Microgravity resulted in a significant 21% increase in flow stasis index, a 22-23% decrease in WSS magnitude and a 16-26% increase in relative residence time in all bifurcation branches, while preserving WSS unidirectionality. In two anatomies, however, microgravity not only promoted flow stasis but also subjected the convex region of the external carotid arterial wall to a moderate increase in WSS bidirectionality, which contrasted with the population average trend. This study suggests that long-term exposure to microgravity has the potential to subject the vasculature to atheroprone hemodynamics and this effect is modulated by subject-specific anatomical features. The exploration of the biological impact of those microgravity-induced WSS aberrations is needed to better define the risk posed by long spaceflights on cardiovascular health.

New Insights on the Toxicity on Heart and Vessels of Breast Cancer Therapies

Cardiovascular diseases are largely represented in patients with cancer and appear to be important side effects of cancer treatments, heavily affecting quality of life and leading to premature morbidity and death among cancer survivors. In particular, treatments for breast cancer have been shown to potentially play serious detrimental effects on cardiovascular health. This review aims to explore the available literature on breast cancer therapy-induced side effects on heart and vessels, illustrating the molecular mechanisms of cardiotoxicity known so far. Moreover, principles of cardiovascular risk assessment and management of cardiotoxicity in clinical practice will also be elucidated. Chemotherapy (anthracycline, taxanes, cyclophosphamide and 5-fluorouracil), hormonal therapy (estrogen receptor modulator and gonadotropin or luteinizing releasing hormone agonists) and targeted therapy (epidermal growth factor receptor 2 and Cyclin-dependent kinases 4 and 6 inhibitors) adverse events include arterial and pulmonary hypertension, supraventricular and ventricular arrhythmias, systolic and diastolic cardiac dysfunction and coronary artery diseases due to different and still not well-dissected molecular pathways. Therefore, cardiovascular prevention programs and treatment of cardiotoxicity appear to be crucial to improve morbidity and mortality of cancer survivors.

Cardiovascular Disease Risk Modeling for Astronauts: Making the Leap From Earth to Space

NASA has recently completed several long-duration missions to the International Space Station and is solidifying plans to return to the Moon, with an eye toward Mars and beyond. As NASA pushes the boundaries of human space exploration, the hazards of spaceflight, including space radiation, levy an increasing burden on astronaut health and performance. The cardiovascular system may be especially vulnerable due to the combined impacts of space radiation exposure, lack of gravity, and other spaceflight hazards. On Earth, the risk for cardiovascular disease (CVD) following moderate to high radiation doses is well-established from clinical, environmental, and occupational exposures (largely from gamma- and x-rays). Less is known about CVD risks associated with high-energy charged ions found in space and increasingly used in radiotherapy applications on Earth, making this a critical area of investigation for occupational radiation protection. Assessing CVD risk is complicated by its multifactorial nature, where an individual's risk is strongly influenced by factors such as family history, blood pressure, and lipid profiles. These known risk factors provide the basis for development of a variety of clinical risk prediction models (CPMs) that inform the likelihood of medical outcomes over a defined period. These tools improve clinical decision-making, personalize care, and support primary prevention of CVD. They may also be useful for individualizing risk estimates for CVD following radiation exposure both in the clinic and in space. In this review, we summarize unique aspects of radiation risk assessment for astronauts, and we evaluate the most widely used CVD CPMs for their use in NASA radiation risk assessment applications. We describe a comprehensive dual-use risk assessment framework that supports both clinical care and operational management of space radiation health risks using quantitative metrics. This approach is a first step in using personalized medicine for radiation risk assessment to support safe and productive spaceflight and long-term quality of life for NASA astronauts.

Artificial intelligence opportunities in cardio-oncology: Overview with spotlight on electrocardiography

Cardiovascular disease is a leading cause of death among cancer survivors, second only to cancer recurrence or development of new tumors. Cardio-oncology has therefore emerged as a relatively new specialty focused on prevention and management of cardiovascular consequences of cancer therapies. Yet challenges remain regarding precision and accuracy with predicting individuals at highest risk for cardiotoxicity. Barriers such as access to care also limit screening and early diagnosis to improve prognosis. Thus, developing innovative approaches for prediction and early detection of cardiovascular illness in this population is critical. In this review, we provide an overview of the present state of machine learning applications in cardio-oncology. We begin by outlining some factors that should be considered while utilizing machine learning algorithms. We then examine research in which machine learning has been applied to improve prediction of cardiac dysfunction in cancer survivors. We also highlight the use of artificial intelligence (AI) in conjunction with electrocardiogram (ECG) to predict cardiac malfunction and also atrial fibrillation (AF), and we discuss the potential role of wearables. Additionally, the article summarizes future prospects and critical takeaways for the application of machine learning in cardio-oncology. This study is the first in a series on artificial intelligence in cardio-oncology, and complements our manuscript on echocardiography and other forms of imaging relevant to cancer survivors cared for in cardiology clinical practice.

Radioprotective Mechanisms of Arbutin: A Systematic Review

PURPOSE

Efforts to produce radioprotective agents of high potential are appropriate strategies for overcoming possible IR toxicity in organisms. The present research aims to evaluate the signaling pathways and mechanisms through which arbutin exerts radioprotective effects on organisms.

METHODS

The databases of PubMed, Web of Sciences, Google Scholar, and Scopus were searched to find studies that reported radioprotective effects for arbutin. Besides, the data were searched within the time period from 2010 to 2020.

RESULTS

Five research articles met our criteria, which were included in the analysis based on their relevance to the topic. The present systematic review provides conclusions about various mechanisms and pathways through which arbutin induces radioprotection.

CONCLUSIONS

Based on the relevant studies, various mechanisms can be proposed for inducing radioprotective effects by arbutin, including inhibition of oxidative stress, apoptosis, and inflammation.

Radiation-induced cardiovascular disease: an overlooked role for DNA methylation?

Radiotherapy in cancer treatment involves the use of ionizing radiation for cancer cell killing. Although radiotherapy has shown significant improvements on cancer recurrence and mortality, several radiation-induced adverse effects have been documented. Of these adverse effects, radiation-induced cardiovascular disease (CVD) is particularly prominent among patients receiving mediastinal radiotherapy, such as breast cancer and Hodgkin's lymphoma patients. A number of mechanisms of radiation-induced CVD pathogenesis have been proposed such as endothelial inflammatory activation, premature endothelial senescence, increased ROS and mitochondrial dysfunction. However, current research seems to point to a so-far unexamined and potentially novel involvement of epigenetics in radiation-induced CVD pathogenesis. Firstly, epigenetic mechanisms have been implicated in CVD pathophysiology. In addition, several studies have shown that ionizing radiation can cause epigenetic modifications, especially DNA methylation alterations. As a result, this review aims to provide a summary of the current literature linking DNA methylation to radiation-induced CVD and thereby explore DNA methylation as a possible contributor to radiation-induced CVD pathogenesis.

Biological Protection in Deep Space Missions

During deep space missions, astronauts are exposed to highly ionizing radiation, incl. neutrons, protons and heavy ions from galactic cosmic rays (GCR), solar wind (SW) and solar energetic particles (SEP). This increase the risks for cancerogenisis, damages in central nervous system (CNS), cardiovascular diseases, etc. Large SEP events can even cause acute radiation syndrome (ARS). Long term manned deep space missions will therefor require unique radiation protection strategies. Since it has been shown that physical shielding alone is not sufficient, this paper propose pre-flight screening of the aspirants for evaluation of their level of adaptive responses. Methods for boosting their immune system, should also be further investigated, and the possibility of using radiation effect modulators are discussed. In this paper, especially, the use of vitamin C as a promising non-toxic, cost-effective, easily available radiation mitigator (which can be used hours after irradiation), is described. Although it has previously been shown that vitamin C can decrease radiation-induced chromosomal damage in rodents, it must be further investigated before any conclusions about its radiation mitigating properties in humans can be concluded.

Heart Failure in Breast Cancer Survivors: Focus on Early Detection and Novel Biomarkers

PURPOSE OF REVIEW

Breast cancer survival rate has greatly improved in the last two decades due to the emergence of next-generation anti-cancer agents. However, cardiotoxicity remains a significant adverse effect arising from traditional and emerging chemotherapies as well as targeted therapies for breast cancer patients. In this review, we will discuss cardiotoxicities of both traditional and emerging therapies for breast cancer. We will discuss current practices to detect cardiotoxicity of these therapies with the focus on new and emerging biomarkers. We will then focus on 'omics approaches, especially the use of epigenetics to discover novel biomarkers and therapeutics to mitigate cardiotoxicity.

RECENT FINDINGS

Significant cardiotoxicities of conventional chemotherapies remain and new and unpredictable new forms of cardiac and/or vascular toxicity emerge with the surge in novel and targeted therapies. Yet, there is no clear guidance on detection of cardiotoxicity, except for significant left ventricular systolic dysfunction, and even then, there is no uniform definition of what constitutes cardiotoxicity. The gold standard for detection of cardiotoxicity involves a serial echocardiography in conjunction with blood-based biomarkers to detect early subclinical cardiac dysfunction. However, the ability of these tests to detect early disease remains limited and not all forms of toxicity are detectable with these modalities. There is an unprecedented need to discover novel biomarkers that are sensitive and specific for early detection of subclinical cardiotoxicity. In that space, novel echocardiographic techniques, such as strain, are becoming more common-place and new biomarkers, discovered by epigenetic approaches, seem to become promising alternatives or adjuncts to conventional non-specific cardiac biomarkers.

The Importance of Primary Care in Cardio-Oncology

OPINION STATEMENT

There is significant interplay between cancer and cardiovascular disease involving shared risk factors, cross disease communication where cardiovascular events can influence cancer recurrence, and mortality rates and cardiotoxicity from cancer treatments with resultant increased cardiovascular mortality and morbidity in cancer patients. This is a major cause of death in many long-term cancer survivors. As a result, cardio-oncology, which involves the prevention, early detection, and optimal treatment of cardiovascular disease in patients treated for cancer, is expanding globally. However, there is still limited awareness of its importance and limited application of the lessons already learnt. Primary care physicians, and their clinical teams, especially nursing colleagues, have a foundation role in the management of all patients, and this paper outlines areas where they can lead in the cardio-oncology management of cancer patients. Although there is currently a lack of an adequate clinical framework or shared care plan, primary care physicians have a role to play in the various phases of cancer treatment: pre-therapy, during therapy, and survivorship.

Radiation Induces Valvular Interstitial Cell Calcific Response in an in vitro Model of Calcific Aortic Valve Disease

Background: Mediastinal ionizing radiotherapy is associated with an increased risk of valvular disease, which demonstrates pathological hallmarks similar to calcific aortic valve disease (CAVD). Despite advances in radiotherapy techniques, the prevalence of comorbidities such as radiation-associated valvular disease is still increasing due to improved survival of patients receiving radiotherapy. However, the mechanisms of radiation-associated valvular disease are largely unknown. CAVD is considered to be an actively regulated disease process, mainly controlled by valvular interstitial cells (VICs). We hypothesize that radiation exposure catalyzes the calcific response of VICs and, therefore, contributes to the development of radiation-associated valvular disease.

Methods and Results: To delineate the relationship between radiation and VIC behavior (morphology, calcification, and matrix turnover), two different in vitro models were established: (1) VICs were cultured two-dimensional (2D) on coverslips in control medium (CM) or osteogenic medium (OM) and irradiated with 0, 2, 4, 8, or 16 Gray (Gy); and (2) three-dimensional (3D) hydrogel system was designed, loaded with VICs and exposed to 0, 4, or 16 Gy of radiation. In both models, a dose-dependent decrease in cell viability and proliferation was observed in CM and OM. Radiation exposure caused myofibroblast-like morphological changes and differentiation of VICs, as characterized by decreased αSMA expression. Calcification, as defined by increased alkaline phosphatase activity, was mostly present in the 2D irradiated VICs exposed to 4 Gy, while after exposure to higher doses VICs acquired a unique giant fibroblast-like cell morphology. Finally, matrix turnover was significantly affected by radiation exposure in the 3D irradiated VICs, as shown by decreased collagen staining and increased MMP-2 and MMP-9 activity.

Conclusions: The presented work demonstrates that radiation exposure enhances the calcific response in VICs, a hallmark of CAVD. In addition, high radiation exposure induces differentiation of VICs into a terminally differentiated giant-cell fibroblast. Further studies are essential to elucidate the underlying mechanisms of these radiation-induced valvular changes.

The relationship between cardiac dosimetry and tumour quadrant location in left sided whole breast and chest wall adjuvant radiotherapy

BACKGROUND

Radiotherapy after breast surgery decreases locoregional recurrence and improves survival. This is not without risks from radiation exposure and could have implications in clinical practice. Our study investigates the correlation between tumour location and radiation dose to the heart.

METHODS

Left-sided breast cancer patients who had radiotherapy at Aberdeen Royal Infirmary in 2010 were identified. Tumour location was established from notes and imaging. Radiotherapy planning scans were reviewed, and cardiac doses calculated. The mean cardiac dose, maximum dose and volume of the heart in the field, along with V5-V40, were determined.

RESULTS

40 patients had mastectomies and 118 breast conserving surgery. The median percentage of the heart in the field and the Interquartile Range was 0.59% (0.03-1.74) for all patients, with the highest for lower inner quadrant (LIQ) tumours 1.20% (0.29-2.40), followed by mastectomy 0.94% (0.02-1.82). The mean heart dose showed a higher median for mastectomies 1.59 Gy (1.00-1.94), followed by LIQ tumours 1.58 Gy (1.31-2.28), with an overall median of 1.42 Gy (1.13-1.95). The median percentage of the heart in the field, the mean cardiac dose and V5-V30 did not reach statistical significance, however, V40 and the maximum dose did.

CONCLUSIONS

The benefits of radiotherapy after breast cancer surgery are established, but with potential harm from cardiac exposure. Our cohort showed higher radiation exposure to the heart in patients with LIQ tumours and mastectomies but reached significance only for V40 and maximum dose. This highlights tumour location as a potentially important risk factor for cardiac exposure with breast radiotherapy.

What can space radiation protection learn from radiation oncology?

Protection from cosmic radiation of crews of long-term space missions is now becoming an urgent requirement to allow a safe colonization of the moon and Mars. Epidemiology provides little help to quantify the risk, because the astronaut group is small and as yet mostly involved in low-Earth orbit mission, whilst the usual cohorts used for radiation protection on Earth (e.g. atomic bomb survivors) were exposed to a radiation quality substantially different from the energetic charged particle field found in space. However, there are over 260,000 patients treated with accelerated protons or heavier ions for different types of cancer, and this cohort may be useful for quantifying the effects of space-like radiation in humans. Space radiation protection and particle therapy research also share the same tools and devices, such as accelerators and detectors, as well as several research topics, from nuclear fragmentation cross sections to the radiobiology of densely ionizing radiation. The transfer of the information from the cancer radiotherapy field to space is manifestly complicated, yet the two field should strengthen their relationship and exchange methods and data.

Failla Memorial Lecture: The Many Facets of Heavy-Ion Science

Heavy ions are riveting in radiation biophysics, particularly in the areas of radiotherapy and space radiation protection. Accelerated charged particles can indeed penetrate deeply in the human body to sterilize tumors, exploiting the favorable depth-dose distribution of ions compared to conventional X rays. Conversely, the high biological effectiveness in inducing late effects presents a hazard for manned space exploration. Even after half a century of accelerator-based experiments, clinical applications and flight research, these two topics remain both fascinating and baffling. Heavy-ion therapy is very expensive, and despite the clinical success it remains controversial. Research on late radiation morbidity in spaceflight led to a reduction in uncertainty, but also pointed to new risks previously underestimated, such as possible damage to the central nervous system. Recently, heavy ions have also been used in other, unanticipated biomedical fields, such as treatment of heart arrhythmia or inactivation of viruses for vaccine development. Heavy-ion science nicely merges physics and biology and remains an extraordinary research field for the 21st century.

Molecular Mechanisms of Specific Cellular DNA Damage Response and Repair Induced by the Mixed Radiation Field During Boron Neutron Capture Therapy

The impact of a mixed neutron-gamma beam on the activation of DNA damage response (DDR) proteins and non-coding RNAs (ncRNAs) is poorly understood. Ionizing radiation is characterized by its biological effectiveness and is related to linear energy transfer (LET). Neutron-gamma mixed beam used in boron neutron capture therapy (BNCT) can induce another type of DNA damage such as clustered DNA or multiple damaged sites, as indicated for high LET particles, such as alpha particles, carbon ions, and protons. We speculate that after exposure to a mixed radiation field, the repair capacity might reduce, leading to unrepaired complex DNA damage for a long period and may promote genome instability and cell death. This review will focus on the poorly studied impact of neutron-gamma mixed beams with an emphasis on DNA damage and molecular mechanisms of repair. In case of BNCT, it is not clear which repair pathway is involved, and recent experimental work will be presented. Further understanding of BNCT-induced DDR mechanisms may lead to improved therapeutic efficiency against different tumors.

A bespoke health risk assessment methodology for the radiation protection of astronauts

An alternative approach that is particularly suitable for the radiation health risk assessment (HRA) of astronauts is presented. The quantity, Radiation Attributed Decrease of Survival (RADS), representing the cumulative decrease in the unknown survival curve at a certain attained age, due to the radiation exposure at an earlier age, forms the basis for this alternative approach. Results are provided for all solid cancer plus leukemia incidence RADS from estimated doses from theoretical radiation exposures accumulated during long-term missions to the Moon or Mars. For example, it is shown that a 1000-day Mars exploration mission with a hypothetical mission effective dose of 1.07 Sv at typical astronaut ages around 40 years old, will result in the probability of surviving free of all types of solid cancer and leukemia until retirement age (65 years) being reduced by 4.2% (95% CI 3.2; 5.3) for males and 5.8% (95% CI 4.8; 7.0) for females. RADS dose-responses are given, for the outcomes for incidence of all solid cancer, leukemia, lung and female breast cancer. Results showing how RADS varies with age at exposure, attained age and other factors are also presented. The advantages of this alternative approach, over currently applied methodologies for the long-term radiation protection of astronauts after mission exposures, are presented with example calculations applicable to European astronaut occupational HRA. Some tentative suggestions for new types of occupational risk limits for space missions are given while acknowledging that the setting of astronaut radiation-related risk limits will ultimately be decided by the Space Agencies. Suggestions are provided for further work which builds on and extends this new HRA approach, e.g., by eventually including non-cancer effects and detailed space dosimetry.

An update in toxicology of ageing

The field of ageing research has been rapidly advancing in recent decades and it had provided insight into the complexity of ageing phenomenon. However, as the organism-environment interaction appears to significantly affect the organismal pace of ageing, the systematic approach for gerontogenic risk assessment of environmental factors has yet to be established. This puts demand on development of effective biomarker of ageing, as a relevant tool to quantify effects of gerontogenic exposures, contingent on multidisciplinary research approach. Here we review the current knowledge regarding the main endogenous gerontogenic pathways involved in acceleration of ageing through environmental exposures. These include inflammatory and oxidative stress-triggered processes, dysregulation of maintenance of cellular anabolism and catabolism and loss of protein homeostasis. The most effective biomarkers showing specificity and relevancy to ageing phenotypes are summarized, as well. The crucial part of this review was dedicated to the comprehensive overview of environmental gerontogens including various types of radiation, certain types of pesticides, heavy metals, drugs and addictive substances, unhealthy dietary patterns, and sedentary life as well as psychosocial stress. The reported effects in vitro and in vivo of both recognized and potential gerontogens are described with respect to the up-to-date knowledge in geroscience. Finally, hormetic and ageing decelerating effects of environmental factors are briefly discussed, as well.

Myocardial Disease and Long-Distance Space Travel: Solving the Radiation Problem

Radiation-induced cardiovascular disease is a well-known complication of radiation exposure. Over the last few years, planning for deep space missions has increased interest in the effects of space radiation on the cardiovascular system, as an increasing number of astronauts will be exposed to space radiation for longer periods of time. Research has shown that exposure to different types of particles found in space radiation can lead to the development of diverse cardiovascular disease via fibrotic myocardial remodeling, accelerated atherosclerosis and microvascular damage. Several underlying mechanisms for radiation-induced cardiovascular disease have been identified, but many aspects of the pathophysiology remain unclear. Existing pharmacological compounds have been evaluated to protect the cardiovascular system from space radiation-induced damage, but currently no radioprotective compounds have been approved. This review critically analyzes the effects of space radiation on the cardiovascular system, the underlying mechanisms and potential countermeasures to space radiation-induced cardiovascular disease.

Trifascicular Block and Ventricular Standstill: A Late Complication of Mediastinal Radiotherapy in a Cancer Survivor

Over the last half-century, radiation therapy has evolved to become one of the cornerstones of treatment for various types of cancers. It is estimated that more than 50% of patients with cancer are treated with radiotherapy. Patients with early stages of some cancers can even achieve a cure with radiotherapy alone. Radiation-induced heart disease is a well-recognized cause of mortality and morbidity in cancer survivors as a late complication of radiotherapy, often occurring more than a decade after radiotherapy. We describe a case of a middle-aged female who presented to the hospital with syncopal episodes. She was in remission from non-Hodgkin's lymphoma having received mediastinal radiotherapy 20 years, previously. Her initial workup such as laboratory investigations and 12 lead electrocardiogram were largely unremarkable. Cardiac monitoring over the course of the next few days was consistent with complete heart block with evidence of ventricular standstill. Her symptoms resolved following the implantation of a dual-chamber cardiac pacemaker. This case highlights the significance of clinical history taking and putting together all relevant facts to come to a differential diagnosis. In our case, this could have been easily overlooked as radiation therapy was given many years previously. We review and present an up-to-date albeit brief literature review on long-term cardiovascular complications of radiotherapy. Radiation-induced cardiac complications are an important cause of mortality and morbidity in cancer survivors. This article aims to raise awareness amongst clinicians of cardiac adverse effects occurring several years after the radiation therapy. This case also highlights the need for further research to better understand the pathophysiology of cardiovascular disease post-radiotherapy in order to develop effective prevention strategies and improve clinical outcomes.

An Interesting Case of a Cold Left Arm

Inter-arm variability in blood pressure readings typically signifies arterial disease between the aortic arch and the subclavian artery. The differential diagnosis includes thoracic aortic dissection, atherosclerosis, thoracic outlet syndrome, and subclavian artery stenosis and thrombosis. In patients with prior coronary artery bypass grafting, including the internal mammary artery, several of those conditions can compromise coronary blood flow and lead to myocardial ischemia. Here we discuss a case of left subclavian artery thrombosis, which compromised left internal mammary artery blood flow and led to ischemic ventricular tachycardia.

Red risks for a journey to the red planet: The highest priority human health risks for a mission to Mars

NASA's plans for space exploration include a return to the Moon to stay-boots back on the lunar surface with an orbital outpost. This station will be a launch point for voyages to destinations further away in our solar system, including journeys to the red planet Mars. To ensure success of these missions, health and performance risks associated with the unique hazards of spaceflight must be adequately controlled. These hazards-space radiation, altered gravity fields, isolation and confinement, closed environments, and distance from Earth-are linked with over 30 human health risks as documented by NASA's Human Research Program. The programmatic goal is to develop the tools and technologies to adequately mitigate, control, or accept these risks. The risks ranked as "red" have the highest priority based on both the likelihood of occurrence and the severity of their impact on human health, performance in mission, and long-term quality of life. These include: (1) space radiation health effects of cancer, cardiovascular disease, and cognitive decrements (2) Spaceflight-Associated Neuro-ocular Syndrome (3) behavioral health and performance decrements, and (4) inadequate food and nutrition. Evaluation of the hazards and risks in terms of the space exposome-the total sum of spaceflight and lifetime exposures and how they relate to genetics and determine the whole-body outcome-will provide a comprehensive picture of risk profiles for individual astronauts. In this review, we provide a primer on these "red" risks for the research community. The aim is to inform the development of studies and projects with high potential for generating both new knowledge and technologies to assist with mitigating multisystem risks to crew health during exploratory missions.

Ionizing Radiation as a Source of Oxidative Stress-The Protective Role of Melatonin and Vitamin D

Ionizing radiation (IR) has found widespread application in modern medicine, including medical imaging and radiotherapy. As a result, both patients and healthcare professionals are exposed to various IR doses. To minimize the negative side effects of radiation associated with oxidative imbalance, antioxidant therapy has been considered. In this review, studies on the effects of melatonin and vitamin D on radiation-induced oxidative stress are discussed. According to the research data, both substances meet the conditions for use as agents that protect humans against IR-induced tissue damage. Numerous studies have confirmed that melatonin, a hydro- and lipophilic hormone with strong antioxidant properties, can potentially be used as a radioprotectant in humans. Less is known about the radioprotective effects of vitamin D, but the results to date have been promising. Deficiencies in melatonin and vitamin D are common in modern societies and may contribute to the severity of adverse side effects of medical IR exposure. Hence, supporting supplementation with both substances seems to be of first importance. Interestingly, both melatonin and vitamin D have been found to selectively radiosensitise cancer cells, which makes them promising adjuvants in radiotherapy. More research is needed in this area, especially in humans.

Stiff to Dilate and Risky to Cut Through: Iliac Radiation Arteritis

Radiation arteritis is not an uncommon clinical situation, given that almost 50% of patients with cancer receive radiotherapy in the course of treatment. Radiation effects are non-specific, and late radiation tissue injury presentation can be very variable. However, radiation arteritis has some unique clinical and radiological features, with consequent special therapeutic considerations. Iliac radiation arteritis may be accompanied by radiation-associated iliac vein disease and small vessel disease. Therefore, diagnostic and therapeutic plans should be directed toward all possible late radiation effects as relevant. Despite the complexity of the disease process and diagnostic challenges, treatment can be very straightforward if adequately planned. Otherwise, limb loss and/or life-threatening complications can rapidly ensue. This article highlights the natural history of radiation arteritis, with a particular emphasis on the iliac segment, and discusses the risk potentials of this condition, given that limb loss may be multifactorial, not merely because of the iliac arterial flow interruption. The main lines of management are also briefly discussed.

High Density Lipoprotein and Its Precursor Protein Apolipoprotein A1 as Potential Therapeutics to Prevent Anthracycline Associated Cardiotoxicity

Cardiovascular disease and cancer are the leading causes of death in developed societies. Despite their effectiveness, many cancer therapies exhibit deleterious cardiovascular side effects such as cardiotoxicity and heart failure. The cardiotoxic effects of anthracyclines such as doxorubicin are the most well-characterized of cardiotoxic anti-cancer therapies. While other anti-neoplastic drugs also induce cardiotoxicity, often leading to heart failure, they are beyond the scope of this review. This review first summarizes the mechanisms of doxorubicin-induced cardiotoxicity. It then reviews emerging preclinical evidence that high density lipoprotein and its precursor protein apolipoprotein A1, which are known for their protective effects against ischemic cardiovascular disease, may also protect against doxorubicin-induced cardiotoxicity both directly and indirectly, when used therapeutically.

The Role of NLRP3 Inflammasome in Radiation-Induced Cardiovascular Injury

The increasing risk of long-term adverse effects from radiotherapy on the cardiovascular structure is receiving increasing attention. However, the mechanisms underlying this increased risk remain poorly understood. Recently, the nucleotide-binding domain and leucine-rich-repeat-containing family pyrin 3 (NLRP3) inflammasome was suggested to play a critical role in radiation-induced cardiovascular injury. However, the relationship between ionizing radiation and the NLRP3 inflammasome in acute and chronic inflammation is complex. We reviewed literature detailing pathological changes and molecular mechanisms associated with radiation-induced damage to the cardiovascular structure, with a specific focus on NLRP3 inflammasome-related cardiovascular diseases. We also summarized possible therapeutic strategies for the prevention of radiation-induced heart disease (RIHD).

Interleukin 10, lipid profile, vitamin D, selenium, metabolic syndrome, and serum antioxidant capacity in elderly people with and without cardiovascular disease: Amirkola health and ageing project cohort-based study

BACKGROUND

The age-related autoinflammation-mediated atherosclerosis is associated with some immunological, nutritional, and metabolic parameters and redox status. Here, we evaluated the association of circulatory interleukin 10 (IL-10) levels with lipid profile, some nutrients, and total anti-oxidant capacity in elderly people who presented cardiovascular disease (CVD) with or without metabolic syndrome (MetS) and in healthy subjects.

METHODS

In this cross-sectional case-control study, 258 sera prepared from elderly people (144 healthy and 114 patient subjects) who participated in a community-based study, the Amirkola Health and Ageing Project (AHAP), were analyzed for IL-10, lipid profile, vitamin D, selenium (Se), antioxidant capacity, and MetS.

RESULTS

Compared to patients, the healthy subjects exhibited higher levels of circulatory IL-10 among individuals with detectable serum IL-10 (P = 0.036). However, this difference was not observed when total subjects from both groups were compared, since more than 90% of those people were IL-10-negative. Se, vitamin D, and antioxidant levels were similar in both groups. There was a negative association between IL-10 and body mass index (BMI) (P < 0.050) and an equivocal association with vitamin D levels, whereas the association between IL-10 and other indicated variables was not significant. Significant association was observed between MetS and CVD prevalence (P < 0.001). There was a positive correlation between Se and total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and triglyceride (TG) (P < 0.010) in healthy subjects and with TC in patients (P < 0.050).

CONCLUSION

A major proportion of elderly people were serum IL-10-negative, whereas independently to IL-10, MetS was most common in patients with CVD. Weight loss may have the potential to increase IL-10 levels in the elderly.

Contrapositive logic suggests space radiation not having a strong impact on mortality of US astronauts and Soviet and Russian cosmonauts

Space travelers are exposed to unique forms of ionizing radiation that pose potentially serious health hazards. Prior analyses have attempted to quantify excess mortality risk for astronauts exposed to space radiation, but low statistical power has frustrated inferences. If exposure to deep space radiation were causally linked to deaths due to two particular causes, e.g., cancer and cardiovascular disease, then those cause-specific deaths would not be statistically independent. In this case, a Kaplan-Meier survival curve for a specific cause that treats deaths due to competing causes as uninformative censored events would result in biased estimates of survival probabilities. Here we look for evidence of a deleterious effect of historical exposure to space radiation by assessing whether or not there is evidence for such bias in Kaplan-Meier estimates of survival probabilities for cardiovascular disease and cancer. Evidence of such bias may implicate space radiation as a common causal link to these two disease processes. An absence of such evidence would be evidence that no such common causal link to radiation exposure during space travel exists. We found that survival estimates from the Kaplan-Meier curves were largely congruent with those of competing risk methods, suggesting that if ionizing radiation is impacting the risk of death due to cancer and cardiovascular disease, the effect is not dramatic.

An oscillometric approach in assessing early vascular ageing biomarkers following long-term space flights

Purpose

The environmental conditions in space, particularly exposure to cosmic radiation, coupled with decreased mobility, altered glucose metabolism, and hemodynamic changes may promote cardiovascular disease Therefore, we assessed early vascular aging markers and hemodynamics using a novel oscillometric blood pressure device.

Methodology

In eight cosmonauts (46.5 ​± ​5.3 ​yrs, 77.6 ​± ​8.2 ​kg, 176 ​± ​6.2 ​cm, 7 men/1woman), we determined heart rate, peripheral blood pressure, central blood pressure, and pulse wave velocity in the supine position using an oscillometric brachial device coupled with transfer function analysis. We obtained measurements at baseline (65–90 days before flight) and four days (R+4) and eight days (R+8) after return from six months mission onboard the International Space Station.

Results

Compared to baseline, heart rate increased significantly on R+4 (58.6 ​± ​6.4 vs. 70.3 ​± ​5.2 bpm) but did not differ on R+8. Central systolic blood pressure increased from 112.5 ​± ​13.5 on baseline to 125.6 ​± ​18.5 on R+4 and 121.6 ​± ​9.5 ​mmHg, albeit showing no statistical significance compared to baseline (p ​= ​0.243/0.295). Peripheral diastolic and systolic as well as central diastolic blood pressure measurements followed this trend. Pulse wave velocity increased non-significantly from baseline (6.7 ​± ​0.8 ​m/s) to R+4 (7.2 ​± ​0.8 ​m/s, p ​= ​0.499) and stayed elevated on R+8 (7.1 ​± ​0.5 ​m/s, p ​= ​0.614).

Conclusion

The important finding of our study is that six months in a near-earth orbit do not lead to clinically significant changes in early vascular ageing biomarkers. However, these findings cannot be extrapolated to the conditions encountered in deep space. Non-invasive testing of vascular biomarkers may have utility in detecting vascular risks during space travel at an early stage.