The late consequences of anthracycline treatment on left ventricular function after treatment for childhood cancer

Assessment of Cardiovascular Function in Childhood Leukemia Survivors: The Role of the Right Heart

Childhood acute lymphoblastic leukemia (ALL) survivors who underwent chemotherapy with anthracyclines have an increased cardiovascular risk. The aim of the study was to evaluate left and right cardiac chamber performances and vascular endothelial function in childhood ALL survivors. Fifty-four ALL survivors and 37 healthy controls were enrolled. All patients underwent auxological evaluation, blood pressure measurements, biochemical parameters of endothelial dysfunction, flow-mediated dilatation (FMD) of the brachial artery, mean common carotid intima-media thickness (c-IMT), antero-posterior diameter of the infra-renal abdominal aorta (APAO), and echocardiographic assessment. The ALL subjects had significantly lower FMD (p = 0.0041), higher left (p = 0.0057) and right (p = 0.0021) echocardiographic/Doppler Tei index (the non-invasive index for combined systolic and diastolic ventricular function) as compared to controls. Tricuspid annular plane excursion (TAPSE) was 16.9 ± 1.2 mm vs. 24.5 ± 3.7 mm, p < 0.0001. Cumulative anthracycline doses were related to TAPSE (p < 0.001). The ALL survivors treated with anthracyclines demonstrated systo/diastolic alterations of the right ventricle and reduced endothelial function compared with healthy controls. The early recognition of subclinical cardiac and vascular impairment during follow up is of utmost importance for the cardiologist to implement strategies preventing overt cardiovascular disease considering the growing number of young adults cured after childhood ALL.

Myocardial extracellular volume derived from contrast-enhanced chest computed tomography for longitudinal evaluation of cardiotoxicity in patients with breast cancer treated with anthracyclines

Objectives

To assess the value of myocardial extracellular volume (ECV) derived from contrast-enhanced chest computed tomography (CT) for longitudinal evaluation of cardiotoxicity in patients with breast cancer (BC) treated with anthracycline (AC).

Materials and methods

A total of 1151 patients with BC treated with anthracyclines, who underwent at least baseline, and first follow-up contrast-enhanced chest CT were evaluated. ECV and left ventricular ejection fraction (LVEF) were measured before (ECV₀, LVEF₀), during ((ECV₁, LVEF₁) and (ECV₂, LVEF₂)), and after (ECV₃, LVEF₃) AC treatment. ECV values were evaluated at the middle of left ventricular septum on venous phase images. Cancer therapy-related cardiac dysfunction (CTRCD) was recorded.

Results

Mean baseline LVEF values were 65.85% ± 2.72% and 102 patients developed CTRCD. The mean ECV₀ was 26.76% ± 3.03% (N₀ = 1151). ECV₁, ECV₂, and ECV₃ (median interval: 61 (IQR, 46–75), 180 (IQR, 170–190), 350 (IQR, 341–360) days from baseline) were 31.32% ± 3.10%, 29.60% ± 3.24%, and 32.05% ± 3.58% (N₁ = 1151, N₂ = 841, N₃ = 511). ECV₁, ECV₂, and ECV₃ were significantly higher than ECV₀ (p < 0.001). ECV₀ and ECV₁ showed no difference between CTRCD (+) and CTRCD (−) group (p₁ = 0.150; p₂ = 0.216). However, ECV₂ and ECV₃ showed significant differences between the two groups (p₃ < 0.001; p₄ < 0.001).

Conclusion

CT-derived ECV is a potential biomarker for dynamic monitoring AC cardiotoxicity in patients with BC.

Subclinical Cardiac Dysfunction in Childhood Cancer Survivors on 10-Years Follow-Up Correlates With Cumulative Anthracycline Dose and Is Best Detected by Cardiopulmonary Exercise Testing, Circulating Serum Biomarker, Speckle Tracking Echocardiography, and Tissue Doppler Imaging

Background: Survivors of childhood cancer are at risk for anthracycline- and/or radiotherapy-induced cardiotoxicity. Aims: The aim of this study was to assess clinical, laboratory, and imaging parameters of subclinical cardiovascular disease in childhood cancer survivors. Methods: Patients underwent cardiopulmonary exercise test (CPET), laboratory testing, transthoracic echocardiography (TTE) with tissue doppler imaging (TDI) and speckle tracking. A subset of patients also underwent cardiovascular magnetic resonance imaging (CMR). Findings were correlated to cumulative anthracycline and exposure to mediastinal irradiation during cancer treatment. In a subgroup analysis, TTE and CMR findings were compared to data from 40 gender- and age-matched patients with childhood onset hypertrophic cardiomyopathy (HCM). Results: Cardiac evaluation was performed in 79 patients (43 males) at 11.2 ± 4.5 years after cancer treatment. Oncologic diagnosis at a median age of 12.0 years was Hodgkin lymphoma in 20, sarcoma in 17, acute leukemia in 24, relapse leukemia in 10, and others in 8 patients. Cumulative anthracycline dose exceeded 300 mg/m² in 28 patients. Twenty six patients also received mediastinal irradiation. Decreased peak respiratory oxygen uptake in % predicted on CPET, increased levels of N-terminal pro-brain natriuretic peptide (NTproBNP), increased global longitudinal strain on TTE speckle tracking, and diastolic dysfunction on TDI were the most prominent findings on detailed cardiology follow-up. In contrast to HCM patients, childhood cancer survivors did not show left ventricular hypertrophy (LVPWd z-score median 0.9 vs. 2.8, p < 0.001), hyperdynamic systolic function on TTE (Ejection fraction 62 ± 7 vs. 72 ± 12%, p = 0.001), or fibrotic myocardial changes on CMR (Late gadolinium positive 0/13 vs. 13/36, p = 0.001; extracellular volume fraction 22 ± 2 vs. 28 ± 3, p < 0.001) at time of follow-up. There was no correlation between chest radiation exposure and abnormal cardiac findings. Cumulative anthracycline dose was the only significant independent predictor on multivariate analysis for any cardiovascular abnormality on follow-up (p = 0.036). Conclusion: Increasing cumulative anthracycline dose during cancer treatment correlates with subclinical cardiac dysfunction in childhood cancer survivors best detected by elevated cardiac serum biomarkers, decreased exercise capacity on CPET, and abnormalities on echocardiographic speckle tracking and TDI.

Statins in anthracycline-induced cardiotoxicity: Rac and Rho, and the heartbreakers

Cancer patients receiving anthracycline-based chemotherapy are at risk to develop life-threatening chronic cardiotoxicity with the pathophysiological mechanism of action not fully understood. Besides the most common hypothesis that anthracycline-induced congestive heart failure (CHF) is mainly caused by generation of reactive oxygen species, recent data point to a critical role of topoisomerase II beta (TOP2B), which is a primary target of anthracycline poisoning, in the pathophysiology of CHF. As the use of the only clinically approved cardioprotectant dexrazoxane has been limited by the FDA in 2011, there is an urgent need for alternative cardioprotective measures. Statins are anti-inflammatory and anti-oxidative drugs that are clinically well established for the prevention of cardiovascular diseases. They exhibit pleiotropic beneficial properties beyond cholesterol-lowering effects that most likely rest on the indirect inhibition of small Ras homologous (Rho) GTPases. The Rho GTPase Rac1 has been shown to be a major factor in the regulation of the pro-oxidative NADPH oxidase as well as in the regulation of type II topoisomerase. Both are discussed to play an important role in the pathophysiology of anthracycline-induced CHF. Therefore, off-label use of statins or novel Rac1 inhibitors might represent a promising pharmacological approach to gain control over chronic cardiotoxicity by interfering with key mechanisms of anthracycline-induced cardiomyocyte cell death.

Impaired Left Ventricular Reserve in Childhood Cancer Survivors Treated With Anthracycline Therapy

BACKGROUND

Childhood cancer survivors show evidence of diffuse myocardial fibrosis that is related to exercise capacity. The mechanism of reduced exercise tolerance in anthracycline cardiotoxicity remains unclear. We explored the determinants of exercise intolerance by evaluating left ventricular (LV) distensibility and functional reserve.

METHODS

Patients (n = 22) and healthy controls (n = 10) underwent two-dimensional echocardiography while supine, upright, and during cycle exercise. LV distensibility was measured as the change in end-diastolic cavity area (EDCA) from supine to the upright position. LV functional reserve was assessed during peak exercise, and measured as the exercise-induced change in systolic circumferential strain rate (SR) and early-diastolic SR (EDSR). The peak rate of oxygen consumption was measured by indirect calorimetry.

RESULTS

Median age of patients was 16 years (range 8-19) and controls 14 years (range 8-19). Median time since anthracycline therapy was 6 years (range 2-16). Peak oxygen consumption was significantly lower in patients compared to controls (35 ml/kg/min [28-60] vs. 45 ml/kg/min [44-53], P = 0.005). Transitioning from the supine position to the upright position caused a similar reduction in LV EDCA, suggesting similar LV distensibility between patients (-22% [-46 to -4]) and controls (-20% [-46 to -3], P = 0.3). However, during exercise, both systolic SR and EDSR reserve were significantly impaired in patients (∆SR: 93% [14-308], ∆EDSR: -4.5% [-88 to 121]) compared to controls (∆SR: 128% [54-230], P = 0.046; ∆EDSR: 74% [22-234], P = 0.02).

CONCLUSIONS

Our findings suggest that impaired LV contractility and functional reserve play a role in the reduced exercise capacity in anthracycline cardiotoxicity rather than LV distensibility.

Myocardial Characterization Using Dual-Energy CT in Doxorubicin-Induced DCM: Comparison With CMR T1-Mapping and Histology in a Rabbit Model

OBJECTIVES

This study sought to evaluate whether patterns of myocardial change in doxorubicin-induced dilated cardiomyopathy determined using dual-energy computed tomography (CT) were similar to characterization by extracellular volume fraction (ECV) using cardiac magnetic resonance (CMR) T1-mapping and collagen volume fraction (CVF) measured using histology.

BACKGROUND

Anthracycline chemoagents are effective against a wide range of malignant conditions. However, cardiotoxicity is a well-known adverse effect of these drugs. Dual-energy CT could be as useful as magnetic resonance (MR) to evaluate myocardial change in anthracycline-induced cardiotoxicity.

METHODS

A dilated cardiomyopathy rabbit model was generated by injecting 11 adult New Zealand rabbits with 1.0 mg/kg of doxorubicin twice weekly for 16 weeks. Contrast-enhanced dual-energy CT and pre-contrast and post-contrast T1-mapping CMR using a prototype modified Look-Locker inversion recovery on a clinical 3-T scanner were performed on 15 rabbits, including 4 control animals, to calculate ECV at baseline, and at 6, 12, and 16 weeks after doxorubicin administration.

RESULTS

The mean ECV values (%) on CT and CMR at 6, 12, and 16 weeks after modeling were significantly higher than those measured at baseline (CT ECV: 35.3%, 41.9%, 42.1% vs. 28.5%; MR ECV: 32.6%, 35.8%, 41.3% vs. 28.8%, respectively; all p < 0.001). CT ECV and MR ECV values were well correlated (r = 0.888; p < 0.001). Both were well correlated with CVF on histology (CT ECV vs. CVF, r = 0.925, p < 0.001 and MR ECV vs. CVF, r = 0.961, p < 0.001, respectively).

CONCLUSIONS

Dual-energy CT ECV correlated well with CMR and histology. Dual-energy CT is useful for characterizing doxorubicin-induced cardiomyopathy by measuring ECV fraction; however, further technical improvements are desirable to lower motion artifact and improve image quality of the iodine map.

Left ventricular strain and strain rates are decreased in children with normal fractional shortening after exposure to anthracycline chemotherapy

BACKGROUND

Anthracycline chemotherapeutic agents carry the well-recognised risk of cardiotoxicity. Previous methods to evaluate cardiac function are useful, but have significant limitations. We sought to determine the left ventricular strain and strain rate of paediatric cancer patients with normal fractional shortening treated with anthracyclines using the latest ultrasound feature-tracking technology.

PATIENTS AND METHODS

Echocardiograms on cancer patients before anthracycline exposure and following completion of treatment were retrospectively analysed using Velocity Vector Imaging software in the circumferential and longitudinal planes. The same analysis was performed on matched controls. Only patients with a fractional shortening ≥28% were included.

RESULTS

In all, 71 patients were identified with an age at diagnosis of 10.5 ± 4.7 years. The time from diagnosis to follow-up was 3.9 ± 4.0 years and the cumulative anthracycline dose was 356 ± 106 mg/m². Following anthracycline exposure, paediatric cancer patients had a higher heart rate and a lower longitudinal strain, longitudinal diastolic strain rate, circumferential strain, and circumferential systolic and diastolic strain rate when compared with controls. Diastolic strain rate showed the greatest percent difference following anthracycline exposure versus controls.

CONCLUSION

Despite having a normal fractional shortening, children exposed to anthracyclines have subclinical derangement of their left ventricular deformation as measured by decreases in strain and strain rate in both the circumferential and longitudinal axis. In particular, there was a profound decrease in diastolic strain rate following anthracycline exposure compared with controls. Whether the decline of strain or strain rate can predict future risk of developing cardiomyopathy requires further investigation.

Are cardiac magnetic resonance imaging and radionuclide ventriculography good options against echocardiography for evaluation of anthracycline induced chronic cardiotoxicity in childhood cancer survivors?

Anthracyclines are widely used for the treatment of solid tumors in pediatric oncology. However, their uses may be limited by progressive chronic cardiotoxicity related to the cumulative dosage. The aims of this study are to compare diagnostic techniques and prepare an algorithm for diagnosis of anthracycline induced chronic cardiotoxicity. The patients were evaluated according to age, sex, time elapsed since the last dose of anthracycline treatment, presence of cardiovascular symptoms, follow-up duration, type of anthracycline, cumulative anthracycline dose, and concomitant mediastinal radiation therapy. Late subclinical cardiotoxicity was detected by history, physical examination, electrocardiography (ECG), Holter monitor, echocardiography (ECHO), radionuclide ventriculography (MUGA), and cardiac magnetic resonance imaging (MRI). Thirty-seven male and 19 female patients with a median age of 11.2 ± 4.6 (range, 3.5-22.0) years were included in the study. Patients were grouped according to cumulative anthracycline doses. Subclinical cardiac dysfunction was detected in 20 patients by at least one of ECHO, MRI or MUGA after anthracycline chemotherapy. We revealed that other than ECHO, MRI and MUGA have high clinical importance for evaluating subclinical late cardiac complications in children treated with anthracyclines.

Diffuse myocardial fibrosis by T1-mapping in children with subclinical anthracycline cardiotoxicity: relationship to exercise capacity, cumulative dose and remodeling

BACKGROUND

The late cardiotoxic effects of anthracycline chemotherapy influence morbidity and mortality in the growing population of childhood cancer survivors. Even with lower anthracycline doses, evidence of adverse cardiac remodeling and reduced exercise capacity exist. We aim to examine the relationship between cardiac structure, function and cardiovascular magnetic resonance (CMR) tissue characteristics with chemotherapy dose and exercise capacity in childhood cancer survivors.

METHODS

Thirty patients (15 ± 3 years), at least 2 years following anthracycline treatment, underwent CMR, echocardiography, and cardiopulmonary exercise testing (peak VO(2)). CMR measured ventricular function, mass, T(1) and T(2) values, and myocardial extracellular volume fraction, ECV, a measure of diffuse fibrosis based on changes in myocardial T1 values pre- and post-gadolinium. Cardiac function was also assessed with conventional and speckle tracking echocardiography.

RESULTS

Patients had normal LVEF (59 ± 7%) but peak VO(2) was 17% lower than age-predicted normal values and were correlated with anthracycline dose (r = -0.49). Increased ECV correlated with decreased mass/volume ratio (r = -0.64), decreased LV wall thickness/height ratio (r = -0.72), lower peak VO(2)(r = -0.52), and higher cumulative dose (r = 0.40). Echocardiographic measures of systolic and diastolic function were reduced compared to normal values (p < 0.01), but had no relation to ECV, peak VO(2) or cumulative dose.

CONCLUSIONS

Myocardial T1 and ECV were found to be early tissue markers of ventricular remodeling that may represent diffuse fibrosis in children with normal ejection fraction post anthracycline therapy, and are related to cumulative dose, exercise capacity and myocardial wall thinning.

Imaging of early modification in cardiomyopathy: the doxorubicin-induced model

Doxorubicin chemotherapy is effective and widely used to treat acute lymphoblastic leukemia. However, its effectiveness is hampered by a wide spectrum of dose-dependent cardiotoxicity including both morphological and functional changes, affecting primarily the myocardium. Non-invasive imaging techniques are used for the diagnosis and monitoring of these cardiotoxic effects. The purpose of this review is to summarize and compare the most common imaging techniques used in early detection and therapeutic monitoring of doxorubicin-induced cardiotoxicity and the suggested mechanisms of such side effects. Imaging techniques using echocardiography including conventional 2D and 3D echocardiography along with MRI sequences including Tagging, Cine, and quantitative MRI in detecting early myocardial damage are also reviewed. As there is a multitude of reported indices and imaging methods to assess particular functional alterations, we limit this review to the most relevant techniques based on their clinical application and their potential to early detection of doxorubicin-induced cardiotoxic effects.

Protective effect of carvedilol on adriamycin-induced left ventricular dysfunction in children with acute lymphoblastic leukemia

BACKGROUND

Adriamycin (ADR) is a potent chemotherapeutic agent widely used in the treatment of childhood acute lymphoblastic leukemia (ALL); its clinical use is limited owing to its marked cardiotoxicity. The present study investigated the possible protective role of carvedilol on ADR-induced left ventricular dysfunction in children with ALL.

METHODS AND RESULTS

Fifty children with newly diagnosed ALL were included in this study. They were divided into 2 equal groups: 1) ADR; and 2) ADR + carvedilol. Patients were evaluated with conventional 2-dimensional echocardiographic examination (2D), pulsed tissue Doppler (PTD), and 2-dimensional longitudinal strain echocardiography (2DS) before and after therapy. Plasma lactic dehydrogenase (LDH), creatine phosphokinase (CPK), and troponin I levels were also determined before and after therapy. ADR treatment reduced left ventricular systolic dysfunction as assessed by a significant decrease in fractional shortening (FS) (2D) and global peak-systolic strain (GPSS; 2DS). In addition, ADR treatment significantly increased plasma troponin I and LDH. Pretreatment of ADR-treated patients with carvedilol resulted in a significant increase in FS (2D) and GPSS (2DS). Furthermore, carvedilol pretreatment inhibited ADR-induced increase in plasma troponin I and LDH.

CONCLUSIONS

These results suggested a protective role of carvedilol against ADR-induced cardiotoxicity.

Nitric oxide: a new biomarker of Doxorubicin toxicity in children?

Doxorubicin (DOX) has been used in the treatment of childhood cancers, but its usage is limited because of cardiotoxicity. There are many studies on the role of nitric oxide (NO) in several cardiac diseases. However, to the authors' knowledge, no studies have investigated the plasma levels of total nitrite, a stable product of NO, in children that received DOX. The authors determined plasma total nitrite levels in 29 children who received DOX and investigated the correlations between these and other clinical and laboratory findings. All patients were in remission during the study period. Plasma total nitrite levels and cardiac functions were determined prospectively. The mean cumulative DOX dose was 310.0 ± 90.9 mg/m(2). In echocardiographic evaluation, 3 patients (10.3%) had a pathological value for ejection fraction (EF) and/or fractional shortening (FS), whereas 11 patients (37.9%) had a threshold value. Total nitrite levels were higher in patients than in matched controls (75.24 ± 39.4 vs 43.14 ± 10.58 μmol/L, respectively, P < .001). It was also found to be higher in patients who had a pathological/threshold value of EF and FS than in patients who had a physiological value of EF and FS (92.35 ± 50.36 vs 59.26 ± 13.56 μmol/L, respectively, P = .038). A negative correlation was found between FS and plasma total nitrite level (r = -.42, P = .023). The authors speculate that increased NO may be a sign of subclinical cardiotoxicity of DOX.

Late cardiotoxicity after low dose of anthracycline therapy for acute lymphoblastic leukemia in childhood

INTRODUCTION

Late cardiotoxicity is a known complication of anthracycline therapy but the long-term effects of low cumulative doses are not well documented. We studied late cardiotoxicity in survivors of childhood acute lymphoblastic leukemia (ALL) treated with low anthracycline doses 10 to 20 years earlier.

METHODS

Seventy-seven ALL survivors who received a cumulative anthracycline dose <250 mg/m² and were at least 10 years after treatment were evaluated for signs of clinical heart failure. Cardiac function was assessed by echocardiography including tissue Doppler measurements of the septal mitral annulus in 37 ALL survivors 10.6-18.3 years (median 13.3 years) after anthracycline treatment with cumulative doses of 180 (n = 19) or 240 mg/m² (n = 18). The control group consisted of 30 healthy volunteers matched for age, sex, BSA, and BMI.

RESULTS

No clinical relevant cardiotoxicity was found. Left ventricular shortening fraction (SF) was significantly reduced in male ALL survivors. Three of the 19 male ALL survivors had an SF below 30%. Male ALL survivors showed a significantly lower early filling velocity to atrial contraction velocity ratio but myocardial velocity during early filling was comparable between patients and controls. ALL survivors had a significantly longer isovolumetric relaxation time (IVRT). Thirty percent of the ALL survivors have an abnormal IVRT compared to the normal range of the controls.

CONCLUSION AND IMPLICATIONS FOR CANCER SURVIVORS

At a median of 13.3 years after exposure to cumulative doses of anthracyclines of 180 or 240 mg/m², no clinical relevant cardiotoxicity was found but subclinical cardiac abnormalities were present in 30% of the patients.

Subclinical cardiac dysfunction and exercise performance in childhood cancer survivors

BACKGROUND

Although anthracycline cardiotoxicity is clearly related to the cumulative dose administered, subclinical cardiac dysfunction has been reported across a wide range of treatment regimens, and its clinical significance is still unclear. Purpose of this study is to investigate by exercise echocardiography for subclinical cardiac dysfunction in survivors of pediatric cancer treated with low-moderate anthracycline doses, and to evaluate whether it may alter the response of the cardiovascular system to dynamic exercise.

PROCEDURE

Post-exercise left ventricular end-systolic wall stress (ESS), left ventricular posterior wall dimension and percent thickening at end systole, and cardiopulmonary exercise test-derived indexes of cardiac function were examined in 55 apparently healthy patients (mean age 13.5 ± 2.9 years, median anthracycline cumulative dose 240 mg/m(2)) and in 63 controls.

RESULTS

Subclinical cardiac dysfunction was identified in 17 patients (30%) presenting reduced left ventricular posterior wall dimension or percent thickening, or increased values of left ventricular ESS as compared to controls (group A), while the remaining patients formed group B. Reduced oxygen consumption at peak exercise in both groups of patients was the only cardiopulmonary exercise test variable resulting significantly different between patients and controls: no differences were found among the groups of patients.

CONCLUSIONS

Our results confirm that even patients treated with a median anthracycline dose of 240 mg/m(2) (range 100-490) are at considerable risk of exhibiting subclinical cardiac dysfunction that, however, does not seem to alter the physiologic response of the cardiovascular system to dynamic exercise.

Effect of telmisartan in limiting the cardiotoxic effect of daunorubicin in rats

Objectives

Studies have suggested that angiotensin receptor blockers may exert a protective role towards doxorubicin-induced cardiotoxicity, but they have not been extensively investigated in this area. We therefore investigated whether the co-treatment of telmisartan, an angiotensin (Ang II) type-1 receptor blocker, might offer protection against daunorubicin cardiotoxic properties in rats.

Methods

Daunorubicin was administered at 3 mg/kg/day every other day for 12 days. Telmisartan was administered orally every day for 12 days.

Key findings

Daunorubicin-treated rats showed cardiac toxicity, evidenced by worsening cardiac function, evaluated by haemodynamic status and echocardiography, elevation of malondialdehyde level and a decreased level of total glutathione peroxidase activity in the heart tissue. These changes were reversed by treatment with telmisartan. Furthermore, telmisartan also downregulated matrix metalloproteinase-2 expression, attenuated the increased protein expression of p22phox, p47phox, p67phox, nuclear factor kappa B and Nox4 in heart tissue, and reduced oxidative-stress-induced DNA damage, which was evaluated by the expression of 8-hydroxydeoxyguanosine. Moreover, telmisartan reduced the myocardial apoptosis induced by daunorubicin.

Conclusions

The present study indicates that telmisartan may improve cardiac function by inhibiting the action of Ang II via AT-1R, which reverses oxidative stress and myocardial apoptosis. This suggests a beneficial effect of telmisartan treatment in the prevention of daunorubicin-induced cardiotoxicity.

Protective effect of carvedilol on daunorubicin-induced cardiotoxicity and nephrotoxicity in rats

Daunorubicin (DNR) is one of the anthracycline anti-tumor agents widely used in the treatment of acute myeloid leukemia. However, the clinical use of DNR has been limited by its undesirable systemic toxicity, especially in the heart and kidney. This study was designed to test the effectiveness of carvedilol, a nonselective beta-blocker against DNR-induced cardiotoxicity and nephrotoxicity. Rats were treated with a cumulative dose of 9 mg/kg body weight DNR (i.v.). Carvedilol was administered orally every day for 6 weeks. DNR rats showed cardiac and nephrotoxicities as evidenced by worsening cardiac and kidney functions, which were evaluated by hemodynamic and echocardiographic studies, and by measuring protein in urine, levels of urea and creatinine in serum, lipid profiles, malondialdeyde level and the total level of glutathione peroxidase activity in both heart and kidney tissues. These changes were reversed by treatment with carvedilol, which resulted in significant improvement in the cardio-renal function. Furthermore, carvedilol down-regulated matrix metalloproteinase-2 expression in the heart, increased nephrin expression in the kidney, and attenuated the increased protein expression of NADPH oxidase subunits in heart and kidney. Moreover, carvedilol reduced myocardial and renal apoptosis and improved the histopathological changes in heart and kidney induced by DNR. In conclusion, the present study demonstrated a beneficial effect of carvedilol treatment in the prevention of DNR-induced cardiotoxicity and nephrotoxicity by reversing the oxidative stress and apoptosis.

Tissue and flow myocardial performance index measurements taken during dobutamine stress echocardiography for early diagnosis of late anthracycline cardiotoxicity

The purpose of this study was to define the role of tissue and flow myocardial performance index (MPI) measured during dobutamine stress and tissue Doppler echocardiography in the early diagnosis of late cardiotoxicity among patients with childhood cancer treated with anthracycline. The study included 20 patients (14 male and 6 female; mean age 18.4 +/- 3.2 years) as the study group and 18 healthy volunteers (14 female and 4 male, mean age: 19.2 +/- 4.0) as the control group. The mean cumulative dose of anthracycline treatment was 282.1 +/- 125.9 mg/m2, and the mean time period after the last dose of anthracycline was 10.2 +/- 4.0 years. Echocardiography was performed during rest and at infusions of 5, 10, 15, and 20 micro/kg/min dobutamine. Although only isovolumetric relaxation and contraction times of the patient group were prolonged at rest, dobutamine infusion showed significant differences in % left ventricle (LV) posterior wall thickening, LV end-systolic wall stress, LV diastolic and systolic diameter, mitral acceleration, and deceleration time in the patient group compared with the control group. Tissue and flow MPI of the LV, tissue MPI of the right ventricle (RV), and interventricular septum of the patient group were higher than the control group throughout the test. LV tissue MPI increased much more than LV flow MPI when stress was increased. In conclusion, LV tissue MPI value during stress is more valuable than LV flow MPI in the early diagnosis of late cardiotoxicity. RV function can be assessed by tissue Doppler MPI.

Anthracycline-induced cardiomyopathy

Anthracyclines are potent chemotherapeutic agents associated with 3 different forms of cardiomyopathy. Acute cardiomyopathy is seen within 3 months of drug exposure and may take the form of either a reversible myocarditis and pericarditis or an early-onset type and a late-onset type of chronic cardiomyopathy. Chronic anthracycline-induced cardiomyopathy is treated similarly to ischemic cardiomyopathies with beta-blockade and angiotensin-converting enzyme (ACE) inhibition. This review focuses on recent research regarding mechanisms of anthracycline-induced myocardial damage, the noninvasive imaging diagnosis of anthracycline-induced cardiomyopathy, and potential areas of future research regarding genetic screening and selecting individuals at increased risk, with consideration of prophylactic treatment with medications, specifically carvedilol and ACE inhibitors.

Is myocardial performance index an independent echocardiographic marker of death in children with idiopathic dilated cardiomyopathy?

BACKGROUND

Myocardial performance index (MPI) was reported as a parameter of ventricular systolic and diastolic function, as well as a useful tool to predict the outcome in patients with ventricular dysfunction.

HYPOTHESIS

To compare MPI with classical echocardiographic parameters as an independent marker of death in children with idiopathic dilated cardiomyopathy (IDCM).

METHODS

Fifty-five children (13 deaths) underwent 104 echocardiograms from January 1996 to May 2005. Right ventricle (RV) MPI and left ventricle (LV) MPI, and 9 classical echocardiographic parameters (left atrium [LA]/body surface area [BSA], distance between mitral E point and ventricular septum, LV mass/body surface area, RV shortening fraction, LV end-systolic and end-diastolic dimensions/body surface area, LV ejection fraction, fiber circumferential shortening velocity, and mitral deceleration time) were compared. Statistical analysis was performed by chi-square, Pearson's correlation and Student t-test, Kaplan-Meier method, Cox's method, and receiver operating curve (ROC). Statistical significance was considered with alpha<0.05 and p=0.80].

RESULTS

Univariate analysis showed that all studied parameters were markers of death. There was a high correlation between RVMPI and LVMPI (r=0.847]-p=0.0001]); therefore, to avoid bias, RVMPI was discharged from multivariate analysis. In the deceased group, moderate/severe mitral regurgitation was frequent (76.9%; confidence interval [CI[ 95%=46.2%- 94.9%) and it was considered in multivariate analysis. In Cox's multivariate analysis, LVMPI was the only independent marker of death (p=0.0213]). The ideal cut-off was 0.63 with 92.3% sensitivity, 66.7% specificity, and fitted ROC area=0.918].

CONCLUSIONS

In children with IDCM, LVMPI is an independent marker of death.

Early detection of doxorubicin cardiomyopathy using two-dimensional strain echocardiography

Doxorubicin is one of the most effective chemotherapeutic agents; however, it causes dose-dependent cardiomyopathy that may lead to heart failure. Conventional measures of ventricular function, such as fractional shortening, are insensitive in detecting early doxorubicin cardiomyopathy. We tested whether novel two-dimensional radial strain echocardiography (2DSE) can detect early doxorubicin injury following chronic administration in a rat model. 14 male Sprague Dawley rats (240 to 260 g) received doxorubicin 2.5 mg/k i.v. per wk for 10 (n=4) or 12 wk (n=10); 17 controls received saline (10 wk, n=7 and 12 wk, n=10). Serial 2DSE from 0 to 12 wk was done at the mid left ventricle using Vivid 7 echo (General Electric, Waukesha, WI, USA). With Q analysis software, radial strain was obtained. From the two-dimensional (2D) image, anatomical M-mode through the anterior/inferior walls was used to measure fractional shortening. Fibrosis (Masson's trichrome) and caspase-3 activity were measured from excised hearts. Radial strain was lower in the doxorubicin group (12 wk: 26.7+/-3 versus 38.3+/-2.6%, p=0.006), with significant difference by 8 wk whereas fractional shortening was lower with doxorubicin only after 12 wk (30.2+/-1.7 versus 37.6+/-1.4%, p=0.02). Doxorubicin group had lower cardiac mass (0.85+/-0.09 versus 1.14+/-0.04 g, p=0.001), higher caspase-3 activity (1.95+/-0.2 fold increase over control, p<0.0001) and fibrosis (3.9 +/- 0.7 versus 0.7+/-0.1%, p=0.005). Radial strain was related directly to cardiac mass (r=0.61, p=0.0007) and inversely to caspase-3 activity (r= -0.5, p=0.005). 2-dimensional radial strain echocardiography is useful in the early detection of doxorubicin cardiac injury and the reduction in radial strain is associated with histologic markers of doxorubicin cardiomyopathy.

Late echocardiography assessment of systolic and diastolic function of the left ventricle in pediatric cancer survivors after anthracycline therapy

BACKGROUND

The usefulness of daunorubicin (DAUNO) and doxorubicin, members of the anthracycline class of anticancer drugs, is limited by their cardiotoxicity. The purpose of our echocardiographic study was to assess the left ventricular (LV) function in long-term pediatric cancer survivors who had received DAUNO and dox as part of their therapy.

PATIENTS AND METHODS

Seventy patients and 70 age, sex, and body surface area matched healthy controls were evaluated. Among the patients, the mean cumulative anthracycline dose was 321.6 (range, 150 to 868 mg/m); the mean interval from cancer diagnosis to evaluation was 13.9 years (range, 7 to 30 y).

RESULTS

Fifteen of the 70 (21.4%) patients had a reduced ejection fraction (EF). Compared with the healthy controls, the mean EF and E/A were decreased to low normal levels in the patients, whereas deceleration time and isovolumetric relaxation time were prolonged. The E/A and deceleration time were significantly different for the females but not the males. The Tissue Doppler Index was normal but the Myocardial Performance Index was prolonged and correlated with EF (r=-0.499, P<0.001). There was a correlation between EF with cumulative anthracycline dose (r=-0.306; P=0.010) and time off therapy (r=-0.281; P=0.019). Diastolic indices suggested a tendency toward abnormal LV relaxation. Myocardial Performance Index seems to be a good index for monitoring LV status, because it was prolonged as EF decreased.

CONCLUSIONS

This study suggests that long-term survivors who received doxorubicin and DAUNO may be found to have subclinical features of myocardial dysfunction when evaluated years after the completion of therapy.

Long-Term Health Status Among Survivors of Childhood Cancer: Does Sex Matter?

Increasing numbers of children diagnosed with cancer will survive their primary malignancy. Within this growing population of long-term survivors, considerable effort has been put forth to identify treatment-related risks for adverse health-related outcomes, such as exposure to alkylating agents, anthracyclines, radiotherapy, and surgery. Patient sex has been identified as a risk factor for numerous long-term adverse outcomes, with female sex more commonly associated with higher risks. In this article, we review the literature, which generally supports associations between female sex and cognitive dysfunction after cranial irradiation, cardiovascular outcomes, obesity, radiation-associated differences in pubertal timing, development of primary hypothyroidism, breast cancer as a second malignant neoplasm and suggests an increased prevalence for the development of osteonecrosis among females. Results of this review support future investigations to further define sex as a risk factor for other common treatment-specific exposures and outcomes. Additionally, research should focus on understanding the underlying biologic and physiological basis of these sex-specific risks. Historically, evidence from both basic science and clinical research has been used to develop risk-stratified therapy, allowing reduction of toxic therapies to low-risk patients without compromising overall survival. With greater knowledge of sex-specific risks, the potential application of sex-specific therapy designed to avoid poor long-term adverse outcomes may become a viable strategy.

Assessment of left ventricular dysfunction in children undergoing chemotherapy

BACKGROUND

In Taiwan, children with malignancies are treated under the protocols of the Taiwan Pediatric Oncology Group (TPOG). The purpose of this study was to determine the change in left ventricular (LV) function in pediatric patients undergoing chemotherapy.

METHODS

A total of 19 pediatric patients (mean age, 12.5 +/- 4.6 years; 11 males, 8 females) were enrolled. We divided the patients into 2 groups: (1) osteogenic sarcoma (OGS) group (n = 12; Group I); and (2) non-osteogenic sarcoma (non-OGS) group (n = 7; Group II). The accumulated dosages of anthracycline in Group I and II patients were 144.3 +/- 56.4 mg/M2 and 131.7 +/- 105.5 mg/M2 (p = 0.735), respectively. The children received echocardiography to investigate the parameters of LV systolic function, LV diastolic function, and myocardial performance index (MPI) after the entire chemotherapy course.

RESULTS

Higher E/A ratio (1.71 +/- 0.37), shorter isovolumic relaxation time (IRT, 42 +/- 19.14 ms), and shorter deceleration time (DT, 140.3 +/- 40.6 ms) were demonstrated in these patients. There was no statistically significant difference in the E/A ratio and DT between the 2 groups. Group I children were older (14.4 +/- 3.7 vs. 9.3 +/- 4.5 years; p = 0.015) and had lower MPI (0.20 +/- 0.02 vs. 0.28 +/- 0.07; p = 0.031) than Group II children.

CONCLUSION

The children treated with chemotherapy using the TPOG protocol had a shorter IRT, higher E/A ratio and shorter DT. No significant evidence of anthracycline-related cardiotoxicity was found in any of the children in this study undergoing chemotherapy with the TPOG protocol.

Systolic and diastolic function in middle aged patients with sickle beta thalassaemia. An echocardiographic study

OBJECTIVE

To evaluate the right and left ventricular systolic and diastolic function in middle aged patients with sickle beta thalassaemia.

METHODS

Forty three patients with sickle beta thalassaemia were recruited for echocardiographic study while 55 controls, matched for age and sex, served as the control group. Parameters measured included: dimensions and wall thickness of left (LV) and right (RV) ventricle and left atrium, LV mass, and cardiac index. LV and RV contractility variables--ejection fraction, circumferential fibre shortening velocity, end systolic stress, end systolic stress/volume index ratio, mitral and tricuspid annulus systolic excursion, and Tei index--were also calculated. The study also evaluated parameters of RV and LV diastolic function including early and late atrioventricular flow velocities (E and A wave respectively), E/A ratio, deceleration time (DT), isovolumic relaxation time (IVRT) as well as pulmonary and hepatic veins systolic to diastolic (S/D) ratio.

RESULTS

Chamber enlargement, greater LV mass index, cardiac index, and RV wall thickness were found in the anaemic group compared with controls. The LV and RV contractility variables of the patients were similar to controls. Conversely the LV and RV Tei index was significantly greater in the patient group. Diastolic dysfunction was present in the anaemic patients resulting from the increased LV and RV A-wave, the longer LVIVRT, RVIVRT, and RVDT, as well as the higher hepatic and pulmonary veins S/D ratio.

CONCLUSIONS

The results show that in middle aged patients with sickle beta thalassaemia the diastolic function is abnormal in both ventricles but still more in RV, whereas the systolic function remains unchanged.

Quantitative assessment of ventricular function in sickle cell disease: effect of long-term erythrocytapheresis

BACKGROUND

Previous studies on cardiac function in patients with sickle cell disease (SCD) demonstrated abnormalities of systolic and diastolic function including elevated left ventricular myocardial performance index (LVMPI) on chronic transfusion protocols. LVMPI has been validated as a useful and easy non-invasive measure of overall cardiac function. Up to now, there are no reported studies on cardiac function in patients with SCD maintained on long-term erythrocytapheresis (LTE).

PROCEDURES

We recorded LVMPI in 22 patients with SCD aged 3-20 years and we compared the results between non-transfused patients (NT-SCD) and patients on LTE (T-SCD).

RESULTS

Males with SCD had higher mean LVMPI than females (P = 0.04). There were significant differences among T-SCD, severe NT-SCD, and mild NT-SCD patients with respect to hemoglobin (Hb) levels (P = .003) and TR velocity (P = .03). T-SCD patients showed elevated LVMPI compared to NT-SCD patients with severe and mild disease (P = 0.002). Pair-wise comparisons demonstrated that T-SCD patients had LVMPI that was significantly higher than NT-SCD (mild) patients (P = 0.01).

CONCLUSIONS

Our study demonstrates that patients SCD on LTE have cardiac dysfunction based on elevated LVMPI. This may be a reflection of the global severity of disease. Our findings merit further investigation with serial monitoring of LVMPI on a larger number of patients with SCD.

Effects of angiotensin II receptor blocker (candesartan) in daunorubicin-induced cardiomyopathic rats

BACKGROUND

Daunorubicin is an anthracycline anti-tumor agent; anthracycline chemotherapy in cancer can cause severe cardiomyopathy leading to a frequently fatal congestive heart failure; the first-line treatment is diuretics and digoxin. Recently, angiotensin-converting enzyme inhibitors have been shown to be effective in the treatment of such toxicity. The purpose of this study was to investigate the effects of angiotensin II type-1 receptor antagonist (candesartan) in a rat model of daunorubicin-induced cardiomyopathy.

METHODS

Rats were treated with a cumulative dose of 9 mg/kg body weight daunorubicin (i.v.). 28 days later, after the development of cardiomyopathy, animals were randomly assigned to candesartan-treated (5 mg/kg/day, p.o.) or vehicle-treated groups; age-matched normal rats were used as the control group. Candesartan treatment was continued for 28 days. Hemodynamic and echocardiographic parameters were measured, cardiac protein and mRNA were analyzed, and histopathological analyses of myocardial fibrosis, cell size and apoptosis were conducted.

RESULTS

Following cardiomyopathy, left ventricular end diastolic pressure and left ventricular systolic dimension were significantly elevated; while % fractional shortening and Doppler E/A ratio were significantly reduced. Cardiomyopathic hearts showed significant increases in % fibrosis, % apoptosis, and myocyte diameter/body weight ratio; candesartan treatment reversed these changes. Fas-L protein overexpression in myopathic hearts was significantly suppressed by treatment with candesartan. Moreover, SERCA2 mRNA and protein expression were both down-regulated in myopathic hearts and restored to normal by candesartan treatment, significantly.

CONCLUSIONS

Our findings suggest that candesartan treatment significantly improved the left ventricular function and reversed the myocardial pathological changes investigated in this model of daunorubicin-induced cardiomyopathy; suggesting its potentials in limiting daunorubicin cardiotoxicity.