Circulating atrial natriuretic peptide plasma levels as a marker for cardiac damage after radiotherapy

Cardiac markers in left-sided breast cancer patients receiving adjuvant radiotherapy: a prospective study

OBJECTIVES

To investigate the association between radiotherapy (RT) and cardiac biomarkers in women with left-sided breast cancer.

METHODS

This prospective observational study recruited patients with stage I-III left-sided breast cancer without coronary heart disease who required adjuvant RT. High-sensitivity troponin I(hsTnI), N-terminal pro-brain natriuretic peptide(NT-proBNP), and high-sensitivity C-reactive protein(hsCRP) levels were measured pre-RT, immediately after RT, and 3 months post-RT. Cardiac-sparing RT techniques were utilized (Field-in-Field IMRT/VMAT ± voluntary deep inspiration breath-hold). Statistical analyses were performed using non-parametric tests and multivariable quantile regression (QR).

RESULTS

One hundred five patients completed the study, with 63 evaluable at three months post-RT. Pre- and post-RT biomarkers showed no significant differences. Median pre-RT and post-RT values were: hsTnI (0.012ng/mL; 0.012ng/mL), hsCRP (3.1 mg/L; 2.8 mg/L), and NT-proBNP (59pg/mL; 45pg/mL). Three months post-RT, hsTnI, hsCRP and NT-proBNP levels also showed no significant differences. Multivariable QR revealed no association between heart Dmean [median(IQR): 2.87 Gy (2.05-3.94)] and post-RT biomarkers. Age and BMI were associated with hsCRP and NT-proBNP, respectively.

CONCLUSIONS

hsTnI, NT-proBNP, and hsCRP are not correlated with contemporary low cardiac exposure in left-sided breast cancer patients treated with contemporary RT techniques.

Investigation of the efficacy of the change ratio of brain natriuretic peptide for predicting the cardiac effects of chemoradiotherapy on esophageal cancer

The aim of this study was to investigate the effectiveness of brain natriuretic peptide (BNP) as a predictor of radiological effects on the heart. A total of 41 patients with esophageal cancer who underwent chemoradiotherapy (CRT) were retrospectively investigated. The BNP levels were measured on the first day of CRT (pre-CRT) and the last day of CRT (post-CRT), and the median concentration of BNP and dosimetric parameters of the heart were calculated. The change ratio of BNP was calculated as follows: [(BNP post-CRT) - (BNP pre-CRT)]/(BNP pre-CRT). The comparison of BNP pre-CRT with post-CRT was performed using a Wilcoxon signed-rank test. The relationship between dosimetric parameters and change ratio was analyzed using Spearman's correlation coefficient. The median levels of BNP of pre-CRT and post-CRT were 10 and 22 pg/ml, respectively, and the difference was statistically significant (P<0.0001). Significant correlations (all P<0.05) were observed between the change ratio and mean dose, V5, V10, V20, and V30. Of the cohort, 14 patients developed acute-to-subacute cardiac events, such as pericardial effusion, cardiomegaly, acute exacerbation of chronic heart failure, and a decreased ejection fraction. The change ratios of BNP, V5, V10, V20, and V30 were significantly higher in patients who experienced cardiac events compared with those who did not. The results of this study showed that BNP measurement, particularly the change ratio of BNP pre- and post-CRT, may be a useful cardiac event predictor in addition to dosimetric parameters.

Murine models of radiation cardiotoxicity: A systematic review and recommendations for future studies

BACKGROUND AND PURPOSE

The effects of radiation on the heart are dependent on dose, fractionation, overall treatment time, and pre-existing cardiovascular pathology. Murine models have played a central role in improving our understanding of the radiation response of the heart yet a wide range of exposure parameters have been used. We evaluated the study design of published murine cardiac irradiation experiments to assess gaps in the literature and to suggest guidance for the harmonisation of future study reporting.

METHODS AND MATERIALS

A systematic review of mouse/rat studies published 1981-2021 that examined the effect of radiation on the heart was performed. The protocol was published on PROSPERO (CRD42021238921) and the findings were reported in accordance with the PRISMA guidance. Risk of bias was assessed using the SYRCLE checklist.

RESULTS

159 relevant full-text original articles were reviewed. The heart only was the target volume in 67% of the studies and simulation details were unavailable for 44% studies. Dosimetry methods were reported in 31% studies. The pulmonary effects of whole and partial heart irradiation were reported in 13% studies. Seventy-eight unique dose-fractionation schedules were evaluated. Large heterogeneity was observed in the endpoints measured, and the reporting standards were highly variable.

CONCLUSIONS

Current murine models of radiation cardiotoxicity cover a wide range of irradiation configurations and latency periods. There is a lack of evidence describing clinically relevant dose-fractionations, circulating biomarkers and radioprotectants. Recommendations for the consistent reporting of methods and results of in vivo cardiac irradiation studies are made to increase their suitability for informing the design of clinical studies.

Biomarkers of radiation-induced vascular injury

OBJECTIVE

Cancer survivorship has thrown the spotlight on the incidence of nonmalignant chronic diseases in cancer patients. Endothelial injury is increasingly recognized as a consequence of cancer treatment, particularly after radiation therapy (RT). This review is to provide a current understanding on the pathophysiological mechanisms and predictive biomarkers of radiation-induced vascular injury.

RECENT FINDINGS

Radiation directly impacts vasculature by causing endothelial apoptosis and senescence, and alterations in normal homeostasis. This altered milieu at the endothelial surface may contribute to a systemic chronic inflammatory state that is superimposed upon the cascade of normal senescence processes leading to acceleration of age-related disorders, atherosclerosis, and chronic fibrosis. Vasculature imaging, blood-based or cell-component biomarkers, and signatures of genomics, proteomics, metabolomics, and radiomics are potential tools for detection of vascular damage after irradiation.

CONCLUSIONS

Development of a valid prediction model by combining an array of imaging tools, blood-based biomarkers, coupled with novel predictors like exosomes and metabolic degradation products can serve to identify RT-induced vascular injury early for subsequent introduction of newer therapeutic approaches to counter radiation morbidity.

B-type natriuretic peptide plasma level in 5-year breast cancer survivors after radiotherapy

BACKGROUND

Left-sided breast cancer patients treated with radiotherapy (RT) are at risk for late radiation-induced cardiovascular complications.

AIM

The aim of this study was to investigate the BNP plasma levels in long-term breast cancer survivors who received only RT as well to assess whether cardiac dose was associated with BNP values.

METHODS

Plasma samples for BNP measurement were repeated in 29 patients (63 ± 11 years) who were alive at 5 years after radiotherapy, free of heart disease and available to provide new blood sample. All patients had BNP measurements at baseline. The ΔBNP was measured to analyze the role of marker variations. No patients received chemotherapy.

RESULTS

The mean cardiac and ventricle dose were 2.1 ± 1.0 (range 0.02-4.5) Gy and 3.0 ± 1.7 (range 0.02-7.6), respectively. Median value of BNP was 47 pg/mL (interquartile ranges, 26-58.2 pg/mL) at baseline, and 34 pg/mL (interquartile ranges, 17.5-54 pg/mL) at 5 years after radiotherapy. There was no significantly different between two measurements (p = ns). Fifteen (52%) reported an improvement in BNP levels, 1 (3%) no changes and 13 (45%) reported a worsening. There was no correlation between ΔBNP and age (p = ns). When patients were stratified according to the median value of dose-volume data, ΔBNP was significantly higher in patients with increased cardiac D_mean (p = .02) and left ventricle D_mean (p = .009).

CONCLUSION

At 5 years after radiotherapy, median plasma BNP levels remained within the normal range, but the delta-BNP levels are directly related to the heart and ventricular dose received.

Early Changes in Cardiovascular Biomarkers with Contemporary Thoracic Radiation Therapy for Breast Cancer, Lung Cancer, and Lymphoma

PURPOSE

We characterized the early changes in cardiovascular biomarkers with contemporary thoracic radiation therapy (RT) and evaluated their associations with radiation dose-volume metrics including mean heart dose (MHD), V5, and V30.

METHODS AND MATERIALS

In a prospective longitudinal study of 87 patients with breast cancer, lung cancer, or mediastinal lymphoma treated with photon or proton thoracic RT, blood samples were obtained pre-RT and after completion of RT (median, 20 days; interquartile range [IQR], 1-35). High-sensitivity cardiac troponin T, N-terminal pro-B-type natriuretic peptide, placental growth factor (PIGF), and growth differentiation factor 15 (GDF-15) were measured. Associations between MHD, V5 and V30, and biomarker levels and associations between echocardiography-derived measures of cardiac function and biomarker levels were assessed in multivariable linear regression models. Analyses were performed according to the following subgroups: (1) breast cancer alone and (2) lung cancer and lymphoma combined.

RESULTS

The median (IQR) estimates of MHD ranged from 1.3 Gy (0.9-2.4) in breast cancer (n = 60) to 6.8 Gy (5.4-10.2) in mediastinal lymphoma (n = 14) and 8.4 Gy (6.7-16.1) in lung cancer (n = 13) patients (P < .001). There were no significant increases in biomarker levels from pre-RT to post-RT in breast cancer. In lung cancer/lymphoma, PIGF increased from a median (IQR) of 20 ng/L (16-26) to 22 ng/L (16-30) (P = .005), and GDF-15 increased from 1171 ng/L (755-2493) to 1887 ng/L (903-3763) (P = .006). MHD, V5, and V30 were significantly associated with post-RT PIGF and GDF-15 levels in multivariable models. Changes in biomarkers were not significantly associated with changes in echocardiography-derived measures of cardiac function.

CONCLUSION

Contemporary thoracic RT induces acute abnormalities in vascular and inflammatory biomarkers that are associated with radiation dose-volume metrics, particularly in lung cancer and mediastinal lymphoma. Long-term follow-up studies are needed to determine the impact of these changes on the development of overt cardiac disease.

Radiation Matters of the Heart: A Mini Review

Radiation Therapy (RT) has been critical in cancer treatment regimens to date. However, it has been shown that ionizing radiation is also associated with increased risk of damage to healthy tissues. At high radiation doses, varied effects including inactivation of cells in treated tissue and associated functional impairment are seen. These range from direct damage to the heart; particularly, diffuse fibrosis of the pericardium and myocardium, adhesion of the pericardium, injury to the blood vessels and stenosis. Cardiac damage is mostly a late responding end-point, occurring anywhere between 1 and 10 years after radiation procedures. Cardiovascular disease following radiotherapy was more common with radiation treatments used before the late 1980s. Modern RT regimens with more focused radiation beams, allow tumors to be targeted more precisely and shield the heart and other healthy tissues for minimizing the radiation damage to normal cells. In this review, we discuss radiation therapeutic doses used and post-radiation damage to the heart muscle from published studies. We also emphasize the need for early detection of cardiotoxicity and the need for more cardio-protection approaches where feasible.

Chagas Disease Diagnostic Applications: Present Knowledge and Future Steps

Chagas disease, caused by the protozoan Trypanosoma cruzi, is a lifelong and debilitating illness of major significance throughout Latin America and an emergent threat to global public health. Being a neglected disease, the vast majority of Chagasic patients have limited access to proper diagnosis and treatment, and there is only a marginal investment into R&D for drug and vaccine development. In this context, identification of novel biomarkers able to transcend the current limits of diagnostic methods surfaces as a main priority in Chagas disease applied research. The expectation is that these novel biomarkers will provide reliable, reproducible and accurate results irrespective of the genetic background, infecting parasite strain, stage of disease, and clinical-associated features of Chagasic populations. In addition, they should be able to address other still unmet diagnostic needs, including early detection of congenital T. cruzi transmission, rapid assessment of treatment efficiency or failure, indication/prediction of disease progression and direct parasite typification in clinical samples. The lack of access of poor and neglected populations to essential diagnostics also stresses the necessity of developing new methods operational in point-of-care settings. In summary, emergent diagnostic tests integrating these novel and tailored tools should provide a significant impact on the effectiveness of current intervention schemes and on the clinical management of Chagasic patients. In this chapter, we discuss the present knowledge and possible future steps in Chagas disease diagnostic applications, as well as the opportunity provided by recent advances in high-throughput methods for biomarker discovery.

Effects of thyroid hormone withdrawal on natriuretic peptides during radioactive iodine therapy in female patients with differentiated thyroid cancer

OBJECTIVE

We aimed to investigate the effects of thyroid hormone withdrawal on N-terminal prohormone forms of atrial natriuretic peptide (NT-proANP) and brain natriuretic peptide (NT-proBNP) during radioiodine therapy in female patients with differentiated thyroid cancer (DTC).

METHODS

Serum concentrations of thyroid-stimulating hormone (TSH), free triiodothyronine (FT3), NT-proANP and NT-proBNP were measured in 51 female patients with DTC (48.7 ± 4.2 years) at three time-points: day of radioiodine therapy (t1 - under acute hypothyroidism), 5 days after radioiodine (t2 - under acute hypothyroidism) and 3 months after radioiodine (t3 - under TSH suppression). Thirty healthy euthyroid women served as controls (42.8 ± 5.6 years).

RESULTS

At t1/t2/t3, median NT-proANP was 5.2/1.7/487 pmol/L vs. 297.7 pmol/L in control group (p < 0.001), median NT-proBNP was 50.1/36.5/79.5 pmol/L vs. 64.5 pmol/L (p < 0.001) and median NT-proANP/NT-proBNP ratios was 0.20/0.18/4.81 vs. 4.14 (p < 0.001). In acute hypothyroidism, FT3 levels were positively correlated with NT-proANP (r = 0.38, p = 0.005), NT-proANP/NT-proBNP ratios (r = 0.47, p = 0.001), heart rate (r = 0.39, p = 0.005), and negatively with mean arterial blood pressure (r = -0.58, p < 0.001).

CONCLUSIONS

Our results indicate that NT-proANP reflects more accurately direct thyroid hormone effects than NT-proBNP. Thyroid hormone-dependent hemodynamic effects seem to be overlapped on the direct stimulatory effect of thyroid hormones on NT-proANP secretion by cardiac myocytes.

Individual response to ionizing radiation

The human response to ionizing radiation (IR) varies among individuals. The first evidence of the individual response to IR was reported in the beginning of the 20th century. Considering nearly one century of observations, we here propose three aspects of individual IR response: radiosensitivity for early or late adverse tissue events after radiotherapy on normal tissues (non-cancer effects attributable to cell death); radiosusceptibility for IR-induced cancers; and radiodegeneration for non-cancer effects that are often attributable to mechanisms other than cell death (e.g., cataracts and circulatory disease). All the molecular and cellular mechanisms behind IR-induced individual effects are not fully elucidated. However, some specific assays may help their quantification according to the dose and to the genetic status. Accumulated data on individual factors have suggested that the individual IR response cannot be ignored and raises some clinical and societal issues. The individual IR response therefore needs to be taken into account to better evaluate the risks related to IR exposure.

Effects of ionizing radiation on the heart

This article provides an overview of studies addressing effects of ionizing radiation on the heart. Clinical studies have identified early and late manifestations of radiation-induced heart disease, a side effect of radiation therapy to tumors in the chest when all or part of the heart is situated in the radiation field. Studies in preclinical animal models have contributed to our understanding of the mechanisms by which radiation may injure the heart. More recent observations in human subjects suggest that ionizing radiation may have cardiovascular effects at lower doses than was previously thought. This has led to examinations of low-dose photons and low-dose charged particle irradiation in animal models. Lastly, studies have started to identify non-invasive methods for detection of cardiac radiation injury and interventions that may prevent or mitigate these adverse effects. Altogether, this ongoing research should increase our knowledge of biological mechanisms of cardiovascular radiation injury, identify non-invasive biomarkers for early detection, and potential interventions that may prevent or mitigate these adverse effects.

Cardiotoxicity of concomitant radiotherapy and trastuzumab for early breast cancer

BACKGROUND

Trastuzumab therapy given in combination with one of several chemotherapy regimens is currently considered the standard of care for the treatment of early-stage, human epidermal growth factor receptor-2 (HER2) -positive breast cancer. The treatment with trastuzumab is due to a significant impact on the survival part of the standard adjuvant treatment of patients with HER2-positive breast cancer. Patients treated with postoperative breast or chest wall irradiation receive trastuzumab concomitant with radiotherapy. In a small proportion of patients trastuzumab causes cardiotoxicity. Preclinical findings indicate a radiosensibilizing effect of trastuzumab in breast cancer cells, but it is not yet clear whether it radiosensibilizes cells of healthy tissues too.

CONCLUSIONS

Special attention is required when left breast or left thoracic wall is irradiated in patient receiving trastuzumab, because long-term effects of the concurrent treatment with trastuzumab and radiotherapy are not yet known. In an era where more patients are surviving a diagnosis of breast cancer, better understanding and earlier detection of therapy-induced cardiac toxicity will be of paramount importance.

The Protective Effect of Beraprost Sodium on Diabetic Cardiomyopathy through the Inhibition of the p38 MAPK Signaling Pathway in High-Fat-Induced SD Rats

Objective. To investigate the effect of beraprost sodium (BPS) on diabetic cardiomyopathy and the underlying mechanism. Methods. A total of 40 Sprague Dawley rats were randomly divided into the normal control group (N = 10) and the model group (N = 30). The model group was fed a high-fat diet followed by a one-time dose of streptozotocin (STZ) to establish the diabetes mellitus model. After that, rats were randomly divided into two groups with or without BPS intervention. After 8 weeks, we explored the role of the p38 MAPK signaling pathway in inflammation, oxidative stress, cardiac morphology, and myocardial apoptosis. Results. Compared with control, the ratio of heart-weight to body-weight and the serum levels of SOD and GSH in the BPS group significantly increased, the expression of p38 MAPK, the serum levels of MDA, TGF-β1, TNF-α, HIF-1α, MMP-9, caspase-3, BNP, ANP, and heart Bax expression significantly decreased, and heart Bcl-2 expression significantly increased. H&E staining in diabetic rats showed the cardiac muscle fibers derangement, the widening gap, the pyknotic and fragmented nuclei, and more apoptosis. Conclusions. BPS effectively showed protective effects on diabetic myocardial cells, possibly through the inhibition of p38 MAPK signaling pathway.

Cardiorespiratory fitness and quality-of-life analysis posttreatment in breast cancer survivors

This study compared VO(2peak), treatment frequency and dosage, and QOL between 22 post-treated breast cancer survivors (CATotal) and 22 apparently healthy, age-matched women (CO). The CATotal group included 11 with no history of any other co-morbidities (CA) and 11 with controlled hypertension (CA + H). VO(2peak) was measured using the Bruce Protocol. QOL was measured using the SF-36 survey. Significant differences were observed in VO(2peak) between CATotal and CO (p = 0.014), CA and CA + H (p = 0.001), and CA + H and CO (p = 0.001). Physical, emotional, and mental health domains of the SF-36 were significantly different between CATotal and CO (p = 0.006, 0.001, and 0.05 respectively). These results suggest that breast cancer survivors with controlled hypertension can experience a significant reduction in VO(2peak) when compared to apparently healthy, age-matched controls. Also, treatment frequency and dosage affected QOL in this group of survivors.

Effects of multiple doses of ionizing radiation on cytokine expression in rat and human cells

PURPOSE

To determine the effect of daily fractionated irradiation on the expression of growth factors and cytokines in different cardiac and vascular cell types.

MATERIALS AND METHODS

Cell cultures of rat cardiac myocytes, fibroblasts, a rat cardiac microvascular endothelial cell line and human artery endothelial cells were irradiated with doses of 2 Gy, given daily during 5 consecutive days. Twenty-four hours after each fraction, gene expression was determined by competitive or semiquantitative polymerase chain reaction. Protein secretion into culture media was determined by enzyme-linked immunoabsorbant assay.

RESULTS

Of all investigated mRNA levels, transforming growth factor (TGF)-ss1 and fibroblast growth factor (FGF)-2 were slightly upregulated in the rat cardiac endothelial cell line after irradiation. TGF-ss1 protein secretion by these cells was slightly, but non-significantly, elevated. Interleukin 1ss protein levels in myocyte culture media were decreased in control cultures at days 3 and 4 compared with day 2. No significant changes were observed in expression of FGF-2 in either of the four cell types. Moreover, no changes were observed in gene expression of platelet-derived growth factors A, B and interleukin 8 in the human artery endothelial cells.

CONCLUSIONS

Fractionated irradiation leads to minor changes in the expression of specific cytokines in cardiac myocytes, fibroblasts and endothelial cells.

Evaluation of biomarkers for cardiotoxicity of anthracyclin-based chemotherapy

Introduction

The clinical assessment of the myocardial damage caused by anthracyclin (ANT)-therapy is difficult. Therefore a study was performed to evaluate non-invasive markers of anthracyclin-induced cardiac effects, with emphasis on course-to-course variation.

Methods

Eligible for study participation were patients, without known cardiologic abnormalities who did not use cardiotoxic medication (except for ANT-therapy), who had previously completed at least three cycles of anthracyclin-containing chemotherapy (n = 14) and patients who were ANT-naïve and who were scheduled to receive doxorubicin-containing chemotherapy (n = 12). Seven patients in this last group also completed at least three cycles and were available for follow-up assessments; thus a total population of 21 patients (12F/9M) completed at least three courses ANT-chemotherapy. In these patients blood samples and ECG-recordings were taken within 6 months after completion of ANT-therapy. In 12 patients (10F/2M) assessments were also done before, immediately afterwards and at 24 h after each course of ANT.

Results and Conclusions

In the patients who completed chemotherapy, NT-proBNP was 277% (n = 21; 95% CI: 86–661%, P < 0.001) higher compared to healthy volunteers. During the first course NT-proBNP rose 269% (n = 12; 167–409%, P < 0.0001) at 24 h post-administration. The linear corrected QT (QTcL) directly after the first administration of ANT increased by 9.56 ms (n = 12; 3.85–15.27, P < 0.001) and this prolongation was still present at 24 h, 11.48 ms (n = 12; 5.61–17.34, P < 0.0001). Both NT-proBNP and QTcL returned to baseline before the start of the next course and a similar pattern was observed during each course. NT-proBNP and QTcL may be useful markers for course-to-course evaluation of anthracyclin-induced cardiotoxicity.

Temporal change in brain natriuretic Peptide after radiotherapy for thoracic esophageal cancer

PURPOSE

To investigate the relationships of plasma levels of brain natriuretic peptide (BNP) with abnormal (18)F-fluorodeoxyglucose (FDG) accumulation in the myocardium corresponding to irradiated fields and temporal changes in BNP, which is used as an index of heart remodeling, after radiotherapy for the mediastinum.

MATERIALS AND METHODS

Brain natriuretic peptide concentrations were measured before and after radiotherapy for thoracic esophageal cancer, and the change in BNP concentration after radiotherapy was investigated. Moreover, FDG accumulation in the myocardium was investigated in patients who had undergone FDG positron emission tomography less than 14 days before or after measurement of BNP concentration, and the Mann-Whitney U test was used to detect significant difference between BNP concentrations in patients with and without abnormal FDG accumulation corresponding to the irradiated field.

RESULTS

There was significant difference between the levels of BNP in patients without abnormal FDG accumulation in the irradiated myocardium and in patients with abnormal FDG accumulation (p < 0.001). The levels of BNP in the 9-24 months after radiotherapy group and in the >24 months after radiotherapy group were significantly higher than the levels in the before radiotherapy group, immediately after radiotherapy group, 1-2 months after radiotherapy group, and control group.

CONCLUSIONS

The level of BNP was significantly increased more than 9 months after the start of radiotherapy and was significantly higher in patients who had high FDG accumulation corresponding to the irradiated field. The results of this study indicate that BNP concentration might be an early indicator of radiation-induced myocardial damage.

Cardiovascular effects of breast cancer radiotherapy

Cardiac toxicity has been implicated as the primary reason for excess non-breast cancer mortality in early breast cancer radiotherapy studies. Refinements in radiotherapy techniques have allowed for a considerable reduction of this risk in the majority of breast cancer patients. Recent large population-based studies confirmed an increase of cardiovascular death risk in patients irradiated for cancer of the left breast and in individuals exposed to relatively low (hitherto believed to be of no cardiovascular disease risk) doses of radiation, such as atomic bomb survivors or patients treated for various benign conditions. The issue of potential radiation-related cardiac damage may also be assuming a new significance due to the widespread use of other cardiotoxic agents, such as anthracyclines, paclitaxel and trastuzumab. The aim of this review is to summarize and critically analyze the available evidence on the impact of ionizing radiation on the cardiovascular system, with special attention to recent data demonstrating previously unrecognized adverse effects. This review discusses the pathology of radiation-related cardiovascular disease, its clinical presentation, risk factors and methods of assessment, as well as technical developments minimizing cardiac exposure. Epidemiological data are presented on the incidence of radiation-induced heart disease and cardiovascular mortality in various populations of patients irradiated for breast cancer and in individuals exposed to low radiation doses. Additionally, non-cardiac radiation-related vascular morbidity and mortality in breast cancer patients are addressed.

The potential cardioprotective effects of amifostine in irradiated rats

PURPOSE

The aim of this study is to determine the cardioprotective efficacy of amifostine. The study consists of researching the relationship between plasma brain natriuretic peptide levels and the electrical and morphologic changes in irradiated rats with or without amifostine.

METHODS AND MATERIALS

Sixty Wistar albino rats were divided into 4 groups, and their hearts were given 15 Gy/fraction with (60)Co. In Groups I and II, the rats were killed after 24 hours to detect early effects; in Groups III and IV, the rats were killed 100 days after irradiation to detect late effects. Before irradiation, Groups I and III received 0.9% saline solution, whereas Groups II and IV received amifostine (200 mg/kg). Twenty rats were used as a control group.

RESULTS

On the 100th day, mild myocardial degeneration was detected in 5 rats (33%) from Group III (no amifostine). This percentage was statistically different from that of Group IV (treated with amifostine) and the controls (p = 0.042). There was no statistically significant difference between the mean plasma brain natriuretic peptide values of the groups (p > 0.05). There was no significant difference in electrocardiographies between the groups. There was no correlation between continuous variables.

CONCLUSION

In the amifostine group (IV) on the 100th day, there was no myocardial degeneration, suggesting that amifostine has a cardioprotective effect.