Corrected QT interval prolongation in anthracycline-treated survivors of childhood cancer

Cardiac safety analysis of anti-HER2-targeted therapy in early breast cancer

To evaluate the cardiac safety of anti-HER2-targeted therapy for early breast cancer; to investigate whether trastuzumab combined with pertuzumab increases cardiac toxicity compared with trastuzumab; to evaluate the predictive value of high-sensitivity Troponin (hs-TnI) and QTc for the cardiotoxicity associated with anti-HER2 targeted therapy in early breast cancer. A total of 420 patients with early-stage HER2-positive breast cancer who received trastuzumab or trastuzumab combined with pertuzumab for more than half a year in Tianjin Medical University Cancer Hospital from January 2018 to February 2021 were included. Left ventricle ejection fraction (LVEF), hs-TnI values, and QTc were measured at baseline and 3, 6, 9, 12 months. Cardiotoxicity was defined as a decrease in LVEF of at least 10 percentage points from baseline on follow-up echocardiography. Cardiotoxicity developed in 67 of the 420 patients (15.9%) and all patients had LVEF above 50% before and after treatment. The incidence of cardiotoxicity in trastuzumab and trastuzumab combined with pertuzumab was 14.3% and 17.9%, respectively (P > 0.05). Logistic regression analysis showed that age, coronary heart disease, left chest wall radiotherapy, and anthracyclines sequential therapy were independent risk factors for cardiotoxicity (P < 0.05). The value of hs-TnI and QTc at the end of treatment (12th month) were selected for ROC curve prediction analysis and the area under the ROC curve was 0.724 and 0.713, respectively, which was significantly different from the area of 0.5 (P < 0.05). The decrease of LVEF in the study was mostly asymptomatic, from the heart safety point of view, the anti-HER2 targeted therapy for early breast cancer was well tolerated. Trastuzumab combined with pertuzumab did not significantly increase cardiotoxicity. However, subgroup analysis suggests that in the presence of coronary artery disease (CAD) and sequential treatment with anthracene, trastuzumab and pertuzumab may increase the cardiac burden compared with trastuzumab. Hs-TnI and QTc may be useful in monitoring and predicting cardiotoxicity associated with anti-HER2 targeted therapy for early breast cancer.

Electrocardiographic abnormalities in childhood cancer survivors treated with cardiotoxic therapy: a systematic review

PURPOSE

The purpose of this study is to assess the available literature on the prevalence and risk factors of electrocardiographic (ECG) abnormalities after cardiotoxic treatment in childhood cancer survivors (CCS).

METHODS

A literature search was performed within MEDLINE, EMBASE, and CENTRAL (1966-11/2020) and reference lists of relevant studies. Studies were eligible for inclusion if they reported ECG abnormalities ≥2 years after cancer diagnosis in ≥50 CCS treated with anthracyclines, RT involving the heart region and/or mitoxantrone. Information about population, treatment, outcome, and risk factors were extracted and risk of bias was assessed.

RESULTS

Of 934 identified publications, 10 studies were included. Outcome definitions, treatment regimens, follow-up period, and risk of bias varied. These ECG abnormalities and prevalences were reported: major (5%-23%) and minor (12%) abnormalities according to the Minnesota Code, rhythm abnormalities (0%-12%), conduction abnormalities (0.3%-7.1%), depolarization abnormalities (0%), and repolarization abnormalities (0%-65%). The reported risk factors of ECG abnormalities (two studies) are male sex, anthracyclines, RT involving the heart region, and hypertension, although results were not univocal between studies and abnormalities.

CONCLUSIONS

Multiple ECG abnormalities have been described in CCS ≥2 years from diagnosis, some of which can have important implications. Future research is needed to evaluate the exact long-term incidence and risk factors, and to investigate their clinical relevance and relation with cardiac dysfunction or future cardiac events. This could improve cardiac surveillance for CCS.

Exercise and Childhood Cancer-A Historical Review

Simple Summary

Childhood cancer survivors are at risk of developing important adverse effects, but there is growing evidence that physical exercise could help in this regard. The present review summarizes the history of pediatric exercise oncology and the main milestones achieved along the way. Overall, physical exercise appears to be safe and beneficial even during the most aggressive phases of pediatric cancer treatment and can represent an effective coadjuvant therapy for attenuating cancer-related adverse effects.

Abstract

Childhood cancer survivors are at risk of developing important adverse effects, many of which persist for years after the end of treatment. The implementation of interventions aiming at attenuating tumor/treatment-associated adverse effects is therefore a major issue in pediatric oncology, and there is growing evidence that physical exercise could help in this regard. The present review aims to summarize the main milestones achieved in pediatric exercise oncology. For this purpose, we conducted a systematic review of relevant studies written in English in the electronic database PubMed (from inception to 14 August 2021). This review traces the field of pediatric exercise oncology throughout recent history based on three fundamental pillars: (i) exercise during childhood cancer treatment; (ii) exercise during/after hematopoietic stem cell transplantation; and (iii) exercise after childhood cancer treatment. Accumulating evidence––although still preliminary in many cases––supports the safety and potential benefits of regular exercise (with no major contraindications in general) in the childhood cancer continuum, even during the most aggressive phases of treatment. Exercise can indeed represent an effective coadjuvant therapy for attenuating cancer-related adverse effects.

Corrected QT interval in hospitalized patients with coronavirus disease 2019: Focus on drugs therapy

Corrected QT (QTc) interval prolongation has been associated with poor patient prognosis. In this study, we assessed the effects of different drugs and cardiac injury on QTc interval prolongation in patients with coronavirus disease 2019 (COVID-19).The study cohort consisted of 395 confirmed COVID-19 cases from the Wuhan Union Hospital West Campus. All hospitalized patients were treated with chloroquine/hydroxychloroquine (CQ/HCQ), lopinavir/ritonavir (LPV/r), quinolones, interferon, Arbidol, or Qingfei Paidu decoction (QPD) and received at least 1 electrocardiogram after drug administration.Fifty one (12.9%) patients exhibited QTc prolongation (QTc ≥ 470 ms). QTc interval prolongation was associated with COVID-19 severity and mortality (both P < .001). Administration of CQ/HCQ (odds ratio [OR], 2.759; 95% confidence interval [CI], 1.318-5.775; P = .007), LPV/r (OR, 2.342; 95% CI, 1.152-4.760; P = .019), and quinolones (OR, 2.268; 95% CI, 1.171-4.392; P = .015) increased the risk of QTc prolongation. In contrast, the administration of Arbidol, interferon, or QPD did not increase the risk of QTc prolongation. Notably, patients treated with QPD had a shorter QTc duration than those without QPD treatment (412.10 [384.39-433.77] vs 420.86 [388.19-459.58]; P = .042). The QTc interval was positively correlated with the levels of cardiac biomarkers (creatine kinase-MB fraction [rho = 0.14, P = .016], high-sensitivity troponin I [rho = .22, P < .001], and B-type natriuretic peptide [rho = 0.27, P < .001]).In conclusion, QTc prolongation was associated with COVID-19 severity and mortality. The risk of QTc prolongation was higher in patients receiving CQ/HCQ, LPV/r, and quinolones. QPD had less significant effects on QTc prolongation than other antiviral agents.

Cardiac Disease in Childhood Cancer Survivors: Risk Prediction, Prevention, and Surveillance: JACC CardioOncology State-of-the-Art Review

Cardiac diseases in the growing population of childhood cancer survivors are of major concern. Cardiotoxicity as a consequence of anthracyclines and chest radiotherapy continues to be relevant in the modern treatment era. Mitoxantrone has emerged as an important treatment-related risk factor and evidence on traditional cardiovascular risk factors in childhood cancer survivors is accumulating. International surveillance guidelines have been developed with the aim to detect and manage cardiac diseases early and prevent symptomatic disease. There is growing interest in risk prediction models to individualize prevention and surveillance. This State-of-the-Art Review summarizes literature from a systematic PubMed search focused on cardiac diseases after treatment for childhood cancer. Here, we discuss the prevalence, risk factors, prevention, risk prediction, and surveillance of cardiac diseases in survivors of childhood cancer.

Electrocardiograms for cardiomyopathy risk stratification in children with anthracycline exposure

Background

Early recognition of anthracycline-induced cardiomyopathy may reduce morbidity and mortality in children, but risk stratification tools are lacking. This study evaluates whether electrocardiogram (ECG) changes precede echocardiographic abnormalities in children with anthracycline-induced cardiomyopathy.

Methods

We performed a retrospective analysis of 589 pediatric cancer patients who received anthracyclines at a tertiary referral center. ECG endpoints were sum of absolute QRS amplitudes in the 6 limb leads (ΣQRS(6 L)) and corrected QT interval (QTc). Cardiomyopathy was defined by echocardiogram as ejection fraction < 50%, shortening fraction < 26%, or left ventricular end-diastolic diameter z-score > 2.5.

Results

Median age at start of therapy was 7.8 years (IQR 3.7–13.6); median follow-up time was 3.6 years (IQR 1.1–5.8). 19.5% of patients met criteria for cardiomyopathy. Male sex, race, older age at first dose, and larger body surface area were associated with development of cardiomyopathy. A 0.6 mV decrease in ΣQRS(6 L) and 10 ms increase in QTc were associated with an increased risk of developing cardiomyopathy with hazard ratios of 1.174 (95% CI = 1.057–1.304, p = 0.003) and 1.098 (95%CI = 1.027–1.173, p = 0.006) respectively. Kaplan-Meier estimates showed a lower chance of cardiomyopathy-free survival for QTc ≥ 440 ms and ΣQRS(6 L) ≤ 3.2 mV over time. After controlling for confounders, total anthracycline dose predicted a decrease in ΣQRS(6 L) and an increase in QTc independent of cardiomyopathy status (p = 0.01 and p < 0.001 respectively). Cardiotoxic radiation did not predict changes in ECG parameters. Cardiomyopathy was associated with increased mortality (34% versus 12%, p < 0.001).

Conclusion

In children receiving anthracyclines, decrease in ΣQRS(6 L) and QTc prolongation are associated with increased risk of developing cardiomyopathy. ECG is a potential non-invasive risk stratification tool for prediction of anthracycline-induced cardiomyopathy and requires prospective validation.

Pyrroloquinoline quinine ameliorates doxorubicin-induced autophagy-dependent apoptosis via lysosomal-mitochondrial axis in vascular endothelial cells

The cardiotoxicity of doxorubicin (DOX) limits its clinical use in the treatment of a variety of solid tumors and malignant hematologic disease. However, the mechanism by which it causes cardiotoxicity is not fully understood. Apoptosis has been regarded as one of mechanisms underlying the cardiotoxic effects of DOX. In our study, we found that treatment of human umbilical vein endothelial cells (HUVECs) with DOX induced autophagy and apoptosis in a dose- and time-dependent manner. Treatment with DOX induced autophagy at earlier time (3 h), then lysosomal membrane permeabilization (LMP) altered after treatment for 12 h which followed by the release of cathepsin D (CTSD). Lysosome-associated membrane proteins-1 and -2 (LAMP1 and LAMP2) were decreased in DOX-treated cells. Additionally, DOX induced the collapse of mitochondrial transmembrane potential, reduction of translocase of the outer mitochondrial membrane-20 (TOM-20), and release of cytochrome c. Furthermore, autophagy inhibitor 3-MA relieved DOX-induced apoptosis as assessed by the expression of cleaved caspase-3, cleaved caspase-9 and TUNEL assay. CTSD inhibitor, pepstatin A, upregulated TOM-20 and suppressed the mitochondria release of cytochrome c as well as apoptosis under DOX stress. Pyrroloquinoline quinine (PQQ), a new B vitamin, ameliorated aforementioned phenomenon. In conclusion, our results suggested that DOX-induced apoptosis was autophagy-dependent via lysosomal-mitochondrial axis. PQQ had an ability to protect cell from autophagy-dependent apoptosis induced by DOX via lysosomal-mitochondrial axis to some extent. This study provided new mechanistic insight toward understanding the pathogenesis of DOX-induced cardiotoxicity and the protection effect of PQQ.

A phase 2 study to assess the pharmacokinetics and pharmacodynamics of CPX-351 and its effects on cardiac repolarization in patients with acute leukemias

PURPOSE

Daunorubicin can induce left ventricular dysfunction and QT interval prolongation. This study assessed the effects of CPX-351, a liposomal encapsulation of cytarabine and daunorubicin, on cardiac repolarization.

METHODS

Twenty-six adults with acute leukemia were treated with CPX-351 for 1-2 induction cycles and ≤ 4 consolidation cycles. The primary endpoint was mean change in QTcF from baseline.

RESULTS

Mean QTcF changes were < 10 ms at all time points. No clinically meaningful effects on heart rate, QRS interval, PR interval, or QTcB were observed. Estimated mean half-lives for total cytarabine and daunorubicin were > 30 h. Thirteen (50%) patients achieved remission. The most common adverse events were febrile neutropenia, fatigue, and nausea.

CONCLUSIONS

The cytarabine and daunorubicin in CPX-351 liposomes were metabolized and excreted similarly to conventional formulation; however, plasma pharmacokinetics were altered. CPX-351 did not prolong the QT interval, suggesting that CPX-351 may induce less cardiotoxicity than previously reported for conventional daunorubicin.

TRIAL REGISTRATION

Clinicaltrials.gov identifier: NCT02238925.

Anthracycline induced cardiotoxicity in adult cancer patients: a prospective cohort study from a specialized oncology treatment centre in Uganda

PURPOSE

To determine the cumulative incidence of anthracycline induced cardiotoxicity (AIC), its predictors, and associated electrocardiographic and echocardiographic manifestations in adult cancer patients at Uganda Cancer Institute (UCI).

METHODS

We enrolled 160 participants between June 2013 and April 2014 and followed them up for a median of 146 days. Data on clinical, electrocardiographic and echocardiographic findings was obtained at baseline, and at completion of chemotherapy. The Pearson chi square test was used to identify the predictors associated with cardiotoxicity.

RESULTS

Of the 64 patients who were accessible for follow-up electrocardiography (ECG) and echocardiography (ECHO), fourteen participants developed cardiotoxicity hence a cumulative incidence rate of 21.9% with 95% CI 13.5%-33.43%. The predictors of AIC were female gender (p=0.025), LVEF (p=0.014) and LVFS (P=0.019). Anthracycline therapy was associated with shortening of the QRS duration (84.3±7.9 Vs 82.1±11.8 ms, p=0.005), prolongation of the QTc interval (411.9±30.7 Vs 447.2±39.4 ms, p=<0.001) and reduction in the LVEF (66.4±7.7 Vs 63.9±8.4%, p=0.026) and LVFS (36.9±6.2 Vs 35.1±6.6%, p=0.03).

CONCLUSION

The cumulative incidence of AIC in this study cohort was high. Our findings emphasize the need for early monitoring for AIC.

Electrophysiological effects of anthracyclines in adult survivors of pediatric malignancy

BACKGROUND

Anthracycline use is limited by cardiotoxicity, including arrhythmias and left ventricular (LV) dysfunction. We aim to characterize the association between electrophysiological changes and LV dysfunction.

METHODS

A retrospective chart review was conducted, including all 147 pediatric cancer survivors at our institution over 18 years of age and treated with an anthracycline. One hundred thirty-four patients who had at least one electrocardiogram (ECG) and echocardiogram were analyzed. The association between dysfunction and baseline characteristics, treatment history, and electrocardigraphic parameters were analyzed using multivariable logistic regression. Additionally, a longitudinal generalized estimating equation (GEE) model was used to examine the temporal association between repeated measure corrected QT (QTc) intervals and subsequent LV function.

RESULTS

In our population, 24% of patients had LV dysfunction. The initial posttreatment QTc interval was longer in patients with LV dysfunction (438 ± 35 vs. 420 ± 20 msec, P = 0.002). In logistic regression analysis, QTc interval (P < 0.001) and cumulative radiation dose (P = 0.027) were associated with LV dysfunction. On ECGs performed prior to evidence of LV dysfunction, the QTc was longer than on ECGs preceding a normal echocardiogram (451 ± 32 msec vs. 423 ± 25 msec, P < 0.001). Mean time from QTc ≥ 450 msec to evidence of LV dysfunction was 1.8 ± 2.9 years. In the longitudinal GEE model, QTc prolongation was associated with subsequent decreased fractional shortening.

CONCLUSIONS

Among adult survivors of pediatric cancer treated with anthracyclines, prolongation of the QTc interval was associated with subsequent LV dysfunction.

Electrocardiographic abnormalities and mortality in aging survivors of childhood cancer: A report from the St Jude Lifetime Cohort Study

BACKGROUND

Electrocardiography (ECG), predictive of adverse outcomes in the general population, has not been studied in cancer survivors. We evaluated the prevalence of ECG abnormalities and associations with mortality among childhood cancer survivors.

METHODS

Major and minor abnormalities were coded per the Minnesota Classification system for participants in the St Jude Lifetime Cohort Study (n = 2,715) and community controls (n = 268). Odds ratios (ORs) and 95% CIs were calculated using multivariable logistic regression; and hazard ratios, using Cox proportional hazards regression.

RESULTS

Survivors were a median age of 31.3 (range 18.4-63.8) years at evaluation and 7.4 (range 0-24.8) years at diagnosis. Prior therapies included cardiac-directed radiation (29.5%), anthracycline (57.9%), and alkylating (60%) chemotherapies. The prevalence of minor ECG abnormalities was similar among survivors and controls (65.2% vs 67.5%, P = .6). Major ECG abnormalities were identified in 10.7% of survivors and 4.9% of controls (P < .001). Among survivors, the most common major abnormalities were isolated ST/T wave abnormalities (7.2%), evidence of myocardial infarction (3.7%), and left ventricular hypertrophy with strain pattern (2.8%). Anthracyclines ≥300 mg/m² (OR 1.7 95% CI 1.1-2.5) and cardiac radiation (OR 2.1 95% CI 1.5-2.9 [1-1,999 cGy], 2.6 95% CI 1.6-3.9 [2,000-2,999 cGy], 10.5 95% CI 6.5-16.9 [≥3,000 cGy]) were associated with major abnormalities. Thirteen participants had a cardiac-related death. Major abnormalities were predictive of all-cause mortality (hazard ratio 4.0 95% CI 2.1-7.8).

CONCLUSIONS

Major ECG abnormalities are common among childhood cancer survivors, associated with increasing doses of anthracyclines and cardiac radiation, and predictive of both cardiac and all-cause mortality.

Cardiotoxicity from anthracycline and cardioprotection in paediatric cancer patients

Notwithstanding the steady progress in survival rates of children and adolescents suffering from cancer, the benefits associated with chemotherapy do not come without risks involving multiple organs and systems, including the cardiovascular apparatus. Anthracyclines-often administered in combination with radiation therapy and/or surgery-are the most used chemotherapeutic compounds in order to treat tumours and blood malignancies even in paediatric age. Being an important side-effect of anthracyclines, carduitoxicity may limit their efficacy during the treatment and induce long-term sequelae, observed even many years after therapy completion. The purpose of this review was to perform an overview about all the possible strategies to prevent and/or limit the anthracyclines adverse side-effects for the cardiovascular system in childhood cancer survivors.

Is screening for abnormal ECG patterns justified in long-term follow-up of childhood cancer survivors treated with anthracyclines?

BACKGROUND

ECG and echocardiography are noninvasive screening tools to detect subclinical cardiotoxicity in childhood cancer survivors (CCSs). Our aims were as follows: (1) assess the prevalence of abnormal ECG patterns, (2) determine the agreement between abnormal ECG patterns and echocardiographic abnormalities; and (3) determine whether ECG screening for subclinical cardiotoxicity in CCSs is justified.

PROCEDURE

We retrospectively studied ECG and echocardiography in asymptomatic CCSs more than 5 years after anthracycline treatment. Exclusion criteria were abnormal ECG and/or echocardiogram at the start of therapy, incomplete follow-up data, clinical heart failure, cardiac medication, and congenital heart disease. ECG abnormalities were classified using the Minnesota Code. Level of agreement between ECG and echocardiography was calculated with Cohen kappa.

RESULTS

We included 340 survivors with a mean follow-up of 14.5 years (range 5-32). ECG was abnormal in 73 survivors (21.5%), with ventricular conduction disorders, sinus bradycardia, and high-amplitude R waves being most common. Prolonged QTc (>0.45 msec) was found in two survivors, both with a cumulative anthracycline dose of 300 mg/m² or higher. Echocardiography showed abnormalities in 44 survivors (12.9%), mostly mild valvular abnormalities. The level of agreement between ECG and echocardiography was low (kappa 0.09). Male survivors more often had an abnormal ECG (corrected odds ratio: 3.00, 95% confidence interval: 1.68-5.37).

CONCLUSIONS

Abnormal ECG patterns were present in 21% of asymptomatic long-term CCSs. Lack of agreement between abnormal ECG patterns and echocardiographic abnormalities may suggest that ECG is valuable in long-term follow-up of CCSs. However, it is not clear whether these abnormal ECG patterns will be clinically relevant.

Evaluation of QTc Interval Prolongation in Breast Cancer Patients after Treatment with Epirubicin, Cyclophosphamide, and Docetaxel and the Influence of Interobserver Variation

BACKGROUND

Chemotherapy with anthracyclines is associated with life-threatening electrocardiographic alterations including corrected QT (QTc) interval prolongation.

PATIENTS AND METHODS

In this study we assessed the effect of epirubicin, cyclophosphamide, and docetaxel (EC-Doc) on the QTc interval in 10 patients with early breast cancer. Cardiac toxicity was assessed with symptoms, transthoracic echocardiography, electrocardiography (ECG), and serum cardiac markers at baseline and after 4 cycles of EC and 4 cycles of docetaxel. To evaluate the influence of interobserver variation, the QTc interval was analyzed by a cardiologist, a gynecologist, and with automated ECG interpretation software.

RESULTS

There was a significant QTc prolongation after EC treatment independent of the investigator. In addition, a significant increase in N-terminal prohormone of brain natriuretic peptide (NT-proBNP) levels was noted after EC treatment. QTc prolongation and NT-proBNP levels normalized after docetaxel treatment. Other biochemical markers were within normal ranges. No clinically relevant effect on left ventricular ejection fraction was observed.

CONCLUSION

This prospective study demonstrated that EC treatment increases the QTc interval and NT-proBNP levels in women with early breast cancer. This effect was reversible and independent of docetaxel administration. Moreover, the treating physician can safely perform QTc interval evaluation as part of clinical routine independent of his/her specialty. Due to the small number of patients, further conclusions are limited at this point.

Burden of Cardiac Arrhythmias in Patients With Anthracycline-Related Cardiomyopathy

OBJECTIVES

The objective of this study was to determine the incidence of arrhythmias and device (internal cardiac defibrillator/cardiac resynchronization therapy defibrillator) therapies in patients with a diagnosis of cardiomyopathy and anthracycline exposure.

BACKGROUND

The burden of arrhythmias in adult cancer survivors with anthracycline-related cardiomyopathy has not been studied, but might have important implications for clinical management and outcomes.

METHODS

Retrospective cohort study of all patients with left ventricular dysfunction (LVD) who underwent internal cardiac defibrillator/cardiac resynchronization therapy defibrillator implantation at the Mayo Clinic from 1990 to 2012. Ninety-five patients were cancer survivors (on average, 5 years), 23 of which had anthracycline-related cardiomyopathy (CA-ACM) and 72 of which had non-anthracycline-related cardiomyopathy (CA-NACM). A second control group of 68 noncancer patients with ischemic heart disease-related LVD or dilated cardiomyopathy (ischemic heart disease [IHD]/DCM) was age- and gender-matched to patients with CA-ACM. All patients were followed for arrhythmias and appropriate ICD therapies, total mortality, heart transplantation, and left ventricular ejection fraction.

RESULTS

More than 5.5 ± 3.0 years after device implantation, nonsustained ventricular tachycardia was the most common arrhythmia in patients with CA-ACM followed by atrial fibrillation and sustained ventricular tachycardia or fibrillation (73.9%, 56.6%, and 30.4%, respectively), which was not significantly different from CA-NACM and IHD/DCM. The 5-year rate of ICD therapies was 19.9% in the CA-ACM group versus 22.1% in the CA-NACM group and 32.6% in the IHD/DCM group (p = NS for both). Device therapy-free, heart transplantation-free, and/or overall survival as well as cardiac function dynamics over time were not different in patients with CA-ACM than in patients with CA-NACM and IHD/DCM.

CONCLUSIONS

This study indicates that the burden of arrhythmia in patients with anthracycline-related cardiomyopathy is not different from cancer and non-cancer patients with IHD-related LVD or DCM.

Electrophysiologic and cellular characteristics of cardiomyocytes after X-ray irradiation

The aim of this study was to investigate possible effects of ionizing irradiation on the electrophysiological functionality of cardiac myocytes in vitro. Primary chicken cardiomyocytes with spontaneous beating activity were irradiated with X-rays (dose range of 0.5-7 Gy). Functional alterations of cardiac cell cultures were evaluated up to 7 days after irradiation using microelectrode arrays. As examined endpoints, cell proliferation, apoptosis, reactive oxygen species (ROS) and DNA damage were evaluated. The beat rate of the cardiac networks increased in a dose-dependent manner over one week. The duration of single action potentials was slightly shortened. Additionally, we observed lower numbers of mitotic and S-phase cells at certain time points after irradiation. Also, the number of cells with γH2AX foci increased as a function of the dose. No significant changes in the level of ROS were detected. Induction of apoptosis was generally negligibly low. This is the first report to directly show alterations in cardiac electrophysiology caused by ionizing radiation, which were detectable up to one week after irradiation.

Cardiac QTc interval characteristics before and after hematopoietic stem cell transplantation: an analysis of 995 consecutive patients at a single center

Hematopoietic stem cell transplantation (HSCT) treats disorders affecting patients of all ages. We studied the rate-corrected cardiac QT interval (QTc) in 995 consecutive children and adults undergoing HSCT at the University of Minnesota. We sought to (1) describe QTc before and after HSCT; (2) describe the change in QTc after HSCT; (3) identify factors affecting QTc and its change; and (4) scrutinize an 'at risk' sub-cohort with a long QTc before HSCT. Pre HSCT: 952 (96%) patients had an evaluable electrocardiography (ECG); median QTc was 426 ms and depended upon disease necessitating transplant. Post HSCT: 506 (51%) patients had an evaluable ECG; median QTc was 441 ms. Intrapatient QTc change: 490 (49%) evaluable patients showed median QTc change (pre to post HSCT) of +16 ms (P<0.0001). At risk group: 68 patients were 'at risk' (long pre-HSCT QTc). In some, 'at-risk' status trended toward predictive of post-transplant nonrelapse mortality. QTc interval prolongation is evident in a large, diverse cohort undergoing HSCT at our institution. Prospective studies of this patient population may be warranted, particularly for 'at-risk' patients who demonstrate significant QTc prolongation both pre and post HSCT.

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.

Cardiotoxicity in childhood cancer survivors: strategies for prevention and management

Advances in cancer treatment have greatly improved survival rates of children with cancer. However, these same chemotherapeutic or radiologic treatments may result in long-term health consequences. Anthracyclines, chemotherapeutic drugs commonly used to treat children with cancer, are known to be cardiotoxic, but the mechanism by which they induce cardiac damage is still not fully understood. A higher cumulative anthracycline dose and a younger age of diagnosis are only a few of the many risk factors that identify the children at increased risk of developing cardiotoxicity. While cardiotoxicity can develop at anytime, starting from treatment initiation and well into adulthood, identifying the best cardioprotective measures to minimize the long-term damage caused by anthracyclines in children is imperative. Dexrazoxane is the only known agent to date, that is associated with less cardiac dysfunction, without reducing the oncologic efficacy of the anthracycline doxorubicin in children. Given the serious long-term health consequences of cancer treatments on survivors of childhood cancers, it is essential to investigate new approaches to improving the safety of cancer treatments.

Cardiovascular status of childhood cancer survivors exposed and unexposed to cardiotoxic therapy

PURPOSE

To determine whether cardiovascular abnormalities in childhood cancer survivors are restricted to patients exposed to cardiotoxic anthracyclines and cardiac irradiation and how risk factors for atherosclerotic disease and systemic inflammation contribute to global cardiovascular status.

METHODS

We assessed echocardiographic characteristics and atherosclerotic disease risk in 201 survivors of childhood cancer with and without exposure to cardiotoxic treatments at a median of 11 years after diagnosis (range, 3 to 32 years) and in 76 sibling controls.

RESULTS

The 156 exposed survivors had below normal left ventricular (LV) mass, wall thickness, contractility, and fractional shortening and above normal LV afterload. The 45 unexposed survivors also had below normal LV mass overall, and females had below normal LV wall thickness. Exposed and unexposed survivors, compared with siblings, had higher levels of N-terminal pro-brain natriuretic peptide (81.7 and 69.0 pg/mL, respectively, v 39.4 pg/mL), higher mean fasting serum levels of non-high-density lipoprotein cholesterol (126.5 and 121.1 mg/dL, respectively, v 109.8 mg/dL), higher insulin levels (10.4 and 10.5 μU/mL, respectively, v 8.2 μU/mL), and higher levels of high-sensitivity C-reactive protein (2.7 and 3.1 mg/L, respectively, v 0.9 mg/L; P < .001 for all comparisons). Age-adjusted, predicted-to-ideal 30-year risk of myocardial infarction, stroke, or coronary death was also higher for exposed and unexposed survivors compared with siblings (2.16 and 2.12, respectively, v 1.70; P < .01 for both comparisons).

CONCLUSION

Childhood cancer survivors not receiving cardiotoxic treatments nevertheless have cardiovascular abnormalities, systemic inflammation, and an increased risk of atherosclerotic disease. Survivorship guidelines should address cardiovascular concerns, including the risk of atherosclerotic disease and systemic inflammation, in exposed and unexposed survivors.

Prospective evaluation of corrected QT intervals and arrhythmias after exposure to epirubicin, cyclophosphamide, and 5-fluorouracil in women with breast cancer

BACKGROUND

Corrected QT (QTc) interval prolongation can induce fatal arrhythmias such as torsade de pointes.

PATIENTS AND METHODS

To assess the characteristics of QTc intervals and arrhythmias in women with early breast cancer who received FEC100 adjuvant chemotherapy, electrocardiograms (ECGs) were recorded before and after each chemotherapy. Associations between QTc interval prolongation and single nucleotide polymorphisms (SNPs) of potassium channel genes were also investigated.

RESULTS

A total of 131 ECG records were obtained in 34 patients who received 153 cycles of FEC100. QTc intervals could be measured in 127 records. There was a significant trend toward QTc interval prolongation after each treatment, persisting through four cycles of chemotherapy (P < 0.001). Median QTc interval prolongations were 13, 11, 18, and 14 ms in the first through fourth cycles of chemotherapy, respectively. QTc intervals differed significantly between cycles 1 and 4 before treatment as well as after treatment (P < 0.05). A single supraventricular premature contraction was noted in 3 (2.3%) of the 131 cycles in 2 (5.9%) of the 34 patients. There was no significant association between QTc interval prolongation and SNPs of potassium channel genes.

CONCLUSION

This prospective study confirmed that FEC100 is associated with significant QTc interval prolongation in women with early breast cancer.

Cardiac Function in Long-Term Survivors of Childhood Lymphoma

Objectives. We studied long-term effects of therapy for childhood lymphoma on cardiac function. Design and patients. We prospectively evaluated 45 survivors of childhood lymphoma, using clinical parameters, electrocardiography and echocardiography. Further comparisons were made between lymphoma subgroups and between males and females. Results. Mean age at diagnosis was 9.1 years. Mean followup duration was 10.9 years. The NYHA functional class was I in 43 patients and II in 2 patients. A prolonged QTc interval (>0.44 msec) was found in 8 patients. Left ventricular (LV) systolic function and compliance were normal (LV shortening fraction 40 ± 5.6%; cardiac index 2.84 ± 1.13 L/min/m²; E/A wave ratio 2.5 ± 1.3; mean ± S.D.), LV mass was normal (97 ± 40 grams/m², mean ± S.D.). Mitral regurgitation was observed in 7/45 patients (16%). Asymptomatic pericardial effusions were found in 3/45 (7%) patients. Conclusions. Long-term follow-up shows that most parameters of cardiac function are normal in survivors of childhood lymphoma. This is likely due to relatively low doses of anthracyclines in modern protocol modalities. Abnormalities in mitral valve flow, QTc prolongation and in a small proportion of survivors, and functional capacity necessitate long-term cardiac follow-up of these patients.

Increased pretransplant QT dispersion as a risk factor for the development of cardiac complications during and after preparative conditioning for pediatric allogeneic hematopoietic stem cell transplantation

Although cardiac complications are some of the most serious complications of HSCT for leukemia, it is difficult to predict them. QTD has been reported as a predictor of heart failure and fatal arrhythmia in adults. The purpose of this study is to examine whether QTD predicts cardiac complications in pediatric HSCT. Eighteen patients (mean age, 6.9 yr; 11 ALL and seven AML) underwent high-dose cyclophosphamide treatment and total body irradiation as preparative conditioning for HSCT. QTD, QTcD, echocardiographic functional parameters, and cumulative anthracycline dose were evaluated. We compared these values between patients with and without cardiac complications. Among 18 patients, seven patients experienced cardiac complications (heart failure in four, arrhythmia in three). There were significant differences in QTD (43.7 ms in patients with cardiac complications vs. 30.2 ms in patients without the complications, p = 0.019) and QTcD (55.3 vs. 36.9 ms, p = 0.003) between the two groups. On the other hand, the cumulative dose of anthracycline and echocardiographic parameters were not significantly different between the two groups. Increases in QTD and QTcD during the pretreatment period may be risk factors for the development of cardiac complications during and after conditioning for pediatric HSCT.

Long-term cardiac follow-up of children treated with anthracycline doses of 300 mg/m2 or less for acute lymphoblastic leukemia

BACKGROUND

The cardiotoxic effect of anthracyclines has been well described for moderate to high cumulative doses (>350 mg/m(2)). However, the question of whether sub-clinical signs of cardiomyopathy may develop and progress over time in children receiving doses of <350 mg/m(2) is controversial. The aim of the present study was to examine cardiac function with serial echocardiography from diagnosis to last follow-up, relapse, or death, and to investigate whether suspected risk factors (e.g., age at diagnosis, gender, cumulative dose, and length of follow-up) had a significant influence on cardiac function.

PROCEDURE

An unselected cohort of 80 patients treated with multi-drug chemotherapy including anthracycline doses of 300 mg/m(2) or less for childhood acute lymphoblastic leukemia was followed with serial echocardiograms. The deviations of each echocardiogram from normal values for the same age and body-surface areas were calculated. The influences of risk factors were analyzed using univariate and multivariate regression. Lowess curves of time dependence were calculated.

RESULTS

All echocardiographic parameters including ejection fraction (EF) deteriorated significantly over time. Male gender was significantly associated with systolic dilatation of the left ventricle and positively associated with left ventricular mass. Reduction of EF was significantly associated with age at diagnosis and male gender.

CONCLUSIONS

Anthracycline doses of <300 mg/m(2) may contribute to a decline in cardiac function over time. Although the deterioration in cardiac parameters was not associated with clinical symptoms, life-long cardiac surveillance for these patients is important to establish the impact of low-dose anthracycline therapy on long-term cardiac health.

Risk-based health monitoring of childhood cancer survivors: a report from the Children's Oncology Group

Because of therapeutic advances over the past 50 years, long-term survival is now a reality for nearly 80% of children and adolescents diagnosed with cancer. The growing population of childhood cancer survivors is notable for its vulnerability to adverse health outcomes, many of which may not become clinically apparent until years after therapy completion. Early detection, prevention, and ameliorative interventions provide the opportunity to reduce cancer-related morbidity and mortality. This review is intended to complement the Children's Oncology Group Long-Term Follow-Up Guidelines for Survivors of Childhood, Adolescent, and Young Adult Cancers. The objective of this review is to familiarize readers with the diverse health risks experienced by childhood cancer survivors that stem from the heterogeneous therapeutic interventions required to achieve disease control.

ProANP and NT-proBNP levels to prospectively assess cardiac function in breast cancer patients treated with cardiotoxic chemotherapy

BACKGROUND

Cardiac function impairment is a known side effect of epirubicin-based chemotherapy. Activation of natriuretic peptides is demonstrated in patients with heart failure.

AIMS

To identify prospectively the cardiotoxic profile of epirubicin-based chemotherapy in breast cancer patients and to evaluate the sensitivity of proANP and NT-proBNP as early biochemical markers of cardiac dysfunction.

METHODS

Forty cancer patients divided in two nonrandomized groups received either epirubicin and paclitaxel (Group A, n=26) or mitoxantrone and docetaxel (Group B, n=14). Control groups, Group C (n=13) and Group D (n=20), consisted of female patients with heart failure and healthy women respectively. Natriuretic peptides and LVEF were determined in all patients.

RESULTS

A statistically significant difference was recorded regarding LVEF before and after treatment in Group A patients (p=0.0001). Three patients had a significant LVEF decline between 10% and 18% from baseline values, while three reached an LVEF value below 50%. All of them presented an increase in proANP and NT-proBNP values (mean increase 270.31+/-124 fmol/ml and 303.57+/-108 fmol/ml, respectively). A significant correlation between the increase in plasma proANP (r=0.8, p<0.0001), as well as NT-proBNP (r=0.7, p<0.0001) and the decrease in LVEF was observed. Regarding Group A, levels of proANP increased from 192.25 fmol/ml before treatment to 287.84 fmol/ml after treatment (p=0.0001), whereas NT-proBNP increased from 152.50 to 242 fmol/ml (p<0.0001) respectively. During follow up, two Group A patients developed congestive heart failure twelve and fourteen months after the completion of chemotherapy respectively. A significant LVEF decline was recorded in both patients during the episode. Regarding Group B, no statistically significant differences were demonstrated.

CONCLUSION

ProANP and NT-proBNP levels might be used as reliable and sensitive markers in the detection of early cardiac impairment caused by epirubicin-based chemotherapy.

Electrocardiographic findings after 5-HT3 receptor antagonists and chemotherapy in children with cancer

BACKGROUND

The antiemetic efficacy of serotonin-type 3 (5-HT3) receptor antagonists has been found to be superior to older antiemetic drugs in cancer patients. Following the administration of these agents, changes in ECG parameters and increased or decreased heart rates have been demonstrated, but there is no sufficient data in children with cancer who are treated with cytotoxic agents. The objective of this study is to evaluate the ECG changes after administration of 5-HT3 receptor antagonists and chemotherapeutic agents in children with cancer.

PROCEDURE

Thirty-eight patients with an age range between 2 and 19 years receiving chemotherapy for solid tumors were included in the study. The patients received 5-HT3 receptor antagonists 30 min before antineoplastic agents in 83 chemotherapy days. Antiemetic therapy consisted of ondansetron in 43 and granisetron in 40 chemotherapy days. Twelve-leads ECGs were obtained four times at the first day of each chemotherapy: just before 30, 90 min, and 24 hr after 5-HT3 receptor antagonists were given. Rate, rhythm, PR interval, QRS duration, ST segment, the shortest (QTca) and the longest (QTcb) QTc intervals with QTc dispersion (QTcd) were all evaluated.

RESULTS

We found a significant shortening of the PR interval and QRS complex durations in the granisetron group at 90th min and at 24th hr, respectively. Also, granisetron infusion caused a significant prolongation of the QTca interval at 90 min.

CONCLUSION

Although we observed minor ECG changes after 5-HT3 receptor antagonists and chemotherapy, neither dangerous rhythm disturbances nor serious ECG changes were seen.

Transient prolonged corrected QT interval in Lyme disease

Lyme disease, caused by the spirochete Borrelia burgdorferi, has known cardiovascular effects typically manifesting in varying degrees of atrioventricular block. Three patients presented with QT interval prolongation associated with Lyme disease, a previously unreported manifestation of Lyme carditis. Implications and a proposed clinical management approach are discussed.

Role of afterload reduction in the prevention of late anthracycline cardiomyopathy

Afterload reduction is useful for treating and preventing adult congestive heart failure outside the realm of anthracycline toxicity. Afterload reducers are commonly used as treatment for acute heart failure associated with anthracyclines. However, the use of afterload reduction for the prevention of anthracycline associated late cardiomyopathy remains a controversial area, with strong opinions expressed concerning the potential risks and benefits of such an approach. This article will define "afterload" and the tools utilized to measure afterload. The study will then describe the theory for the use of afterload reduction in patients with anthracycline exposure who show signs of anthracycline cardiotoxicity, and will present data from the ACE-Inhibitor After Anthracyclines (AAA) Trial to help answer the question, "Should an afterload reducer be used to aid in preventing late anthracycline cardiotoxicity?" Finally, recommendations for future research will be presented.

Pathophysiology of anthracycline- and radiation-associated cardiomyopathies: implications for screening and prevention

Great progress has been made in treating childhood cancers over the past 40 years. Along with second malignancies, a major complication of anti-cancer therapies is adverse cardiovascular effects, especially cardiomyopathy and coronary artery disease. The pathophysiology and characteristics of cardiomyopathy associated with radiation therapy and anthracycline therapy are distinctive. We describe each type of cardiomyopathy, along with its risk factors. These distinctive cardiomyopathies require different screening tests. Appropriate screening of the entire cardiovascular system should be performed because radiation and chemotherapy affect the entire system. Prevention recommendations focus on cardiomyopathy and coronary artery disease.

Effect of Arsenic Trioxide on QT Interval in Patients With Advanced Malignancies

Purpose: Arsenic trioxide is an effective treatment for patients with acute promyelocytic leukemia (APL) who have relapsed from or are refractory to all-trans-retinoic acid and anthracycline chemotherapy. Since arsenic can prolong the QT interval and lead to torsade de pointes, a life-threatening ventricular arrhythmia, this retrospective analysis was conducted to determine the degree of QT prolongation in patients treated with arsenic trioxide.

Patients and Methods: Clinical data and serial ECGs from 99 patients with advanced malignancies who received 170 courses of arsenic trioxide in either a phase I or phase II investigational study were reviewed.

Results: Prolonged QT intervals developed in 38 patients (26 patients had intervals ≥ 500 milliseconds). Compared with baseline, the heart rate—corrected (QTc) interval was prolonged by 30 to 60 milliseconds in 36.6% of treatment courses, and by more than 60 milliseconds in 35.4% of patients. The degree of prolongation was higher in men than in women during the first course of therapy, and in patients with hypokalemia. In patients receiving multiple courses, QTc intervals returned to pretreatment levels before the second course, signifying that arsenic trioxide does not permanently prolong the QTc interval. One hypokalemic, arsenic trioxide–treated patient with relapsed APL developed asymptomatic torsade de pointes, which resolved spontaneously and did not recur after electrolyte replacement. There were no sudden or arrhythmia-related deaths.

Conclusion: This analysis shows that arsenic trioxide can prolong the QTc interval. However, with appropriate ECG monitoring and management of electrolytes and concomitant medications, arsenic trioxide can be safely administered in patients with relapsed APL.

The new cardioprotector Monohydroxyethylrutoside protects against doxorubicin-induced inflammatory effects in vitro

Besides its cardiotoxic effect, doxorubicin also elicits inflammatory effects in vivo. 7-Monohydroxyethylrutoside (monoHER) has recently been used as a protector against doxorubicin-induced cardiotoxicity in vivo. It is not known yet whether monoHER can also protect against doxorubicin-induced inflammatory effects. The aim of the present study was (1) to illustrate the inflammatory effects of doxorubicin in vitro and (2) to evaluate a possibly protective effect of monoHER. In order to demonstrate the inflammatory effects of doxorubicin and the possible protection of monoHER, proliferating human umbilical cord vascular endothelial cells (HUVECs) were incubated with different concentrations of doxorubicin ranging from 12.5 to 600 nM with(out) 200 micro M monoHER. Resting (confluent) HUVECs were incubated with (0.5-25 micro M) doxorubicin with(out) monoHER (0.2-1.2 mM) and the viability of endothelial cells and their propensity to adhere to neutrophils were measured 24 h after treatment. The localisation of adhered neutrophils was determined with immunofluorescence microscopy. To further characterise the mechanism of doxorubicin-induced neutrophil adhesion, the expression of the HUVECs surface adhesion molecules was determined after doxorubicin treatment. Doxorubicin decreased the viability and proliferation capacity of HUVECs in a concentration-dependent manner. The proliferating HUVECs were much more sensitive to doxorubicin (IC(50)=60.0+/-20.8 nM) than resting cells (LC(50)=4.0+/-0.3 micro M). Doxorubicin also increased the adhesion of neutrophils reaching a plateau value at a doxorubicin concentration of > or =0.4 micro M (P=0.0113). The induced neutrophil adhesion was accompanied by overexpression of VCAM and E-selectin but not ICAM. Although monoHER did not reverse the effect of doxorubicin on the proliferation of endothelial cells, it significantly protected resting HUVECs against the cytotoxic effect of doxorubicin (< or =25 micro M, P<0.0015). In addition, monoHER completely protected against the stimulatory effect of doxorubicin on neutrophil adhesion, and inhibited the doxorubin-induced expression of VCAM and E-selectin on the surface of treated HUVECs. This study illustrates that monoHER, which protects against doxorubicin's cardiotoxic effect, can also protect against doxorubicin-induced inflammatory effects. These data prompt further investigation about the possible link between doxorubicin-induced inflammatory effects and its cardiotoxicity in vivo.

Radiation-associated cardiovascular disease

As the number of cancer survivors grows because of advances in therapy, it has become more important to understand the long-term complications of these treatments. This article presents the current knowledge of adverse cardiovascular effects of radiotherapy to the chest. Emphasis is on clinical presentations, recommendations for follow-up, and treatment of patients previously exposed to irradiation. Medline literature searches were performed, and abstracts related to this topic from oncology and cardiology meetings were reviewed. Potential adverse effects of mediastinal irradiation are numerous and can include coronary artery disease, pericarditis, cardiomyopathy, valvular disease and conduction abnormalities. Damage appears to be related to dose, volume and technique of chest irradiation. Effects may initially present as subclinical abnormalities on screening tests or as catastrophic clinical events. Estimates of relative risk of fatal cardiovascular events after mediastinal irradiation for Hodgkin's disease ranges between 2.2 and 7.2 and after irradiation for left-sided breast cancer from 1.0 to 2.2. Risk is life long, and absolute risk appears to increase with length of time since exposure. Radiation-associated cardiovascular toxicity may in fact be progressive. Long-term cardiac follow-up of these patients is therefore essential, and the range of appropriate cardiac screening is discussed, although no specific, evidence-based screening regimen was found in the literature.

Cancer survivorship research: challenge and opportunity

With continued advances in strategies to detect cancer early and treat it effectively along with the aging of the population, the number of individuals living years beyond a cancer diagnosis can be expected to continue to increase. This paper reviews current prevalence data for cancer survivors; discusses definitional issues; examines cancer survivorship as a scientific research area; provides an overview of medical and psychosocial sequelae of cancer diagnosis and treatment experienced by survivors, gaps in knowledge and emerging research priorities; explores the role of weight, nutrition and physical activity as key variables carrying the potential to affect physiologic or psychosocial sequelae of cancer and its treatment; and discusses the evolving paradigm of cancer survivorship research. A large and growing community of cancer survivors is one of the major achievements of cancer research over the past three decades. Both length and quality of survival are important end points. Many cancer survivors are at risk for and develop physiologic and psychosocial late and long-term effects of cancer treatment that may lead to premature mortality and morbidity. Interventions--therapeutic and lifestyle--carry the potential to treat or ameliorate these late effects and must be developed, examined and disseminated if found effective. Diet, weight and physical activity interventions hold considerable promise for ameliorating multiple adverse sequelae of cancer and its treatment and should be investigated in larger populations of cancer survivors, those who are long-term survivors, those with understudied cancer sites and ethnocultural minority or medically underserved groups.

Cardiac status in bone tumor survivors up to nearly 19 years after treatment with doxorubicin: a longitudinal study

BACKGROUND

Longitudinal assessment of cardiac toxicity in anthracycline-treated long-term bone tumor survivors.

PROCEDURES

Cardiac status was assessed in 29 patients 14.1 (range 7-18.7) years after treatment with doxorubicin (DOXO) 360 mg/m(2) (median 225-550). The median age of the patients at the time of the study was 32.5 years (range 19.7-52). The evaluation consisted of an electrocardiogram (ECG), 24-hr ambulatory ECG with analysis of heart rate variability (HRV) and echocardiography. The results were compared to those of a study of the same patients that was performed 5 years earlier 8.9 years (range 2.3-14.1) after treatment. [Postma et al.: Med Pediatr Oncol 26:230-237, 1996]

RESULTS

We found no progression of ECG abnormalities, arrhythmias, or echocardiographic abnormalities. Females were at risk for reduced contractility (P = 0.006). HRV was significantly reduced compared to age- and sex-matched controls and compared to the previous results.

CONCLUSIONS

Anthracycline-related late echocardiographic abnormalities and arrhythmias detected 8.9 years after treatment, showed no further deterioration with ongoing follow-up. However, there was a significant reduction of HRV. This suggests that HRV might be a sensitive test for detection of anthracycline-induced cardiac toxicity.

Frequency and risk factors of subclinical cardiotoxicity after anthracycline therapy in children: a systematic review

BACKGROUND

The aim of this systematic review was to summarise and appraise the published evidence with regard to the frequency and risk factors of subclinical cardiotoxicity in apparently healthy survivors of childhood cancer after anthracycline therapy.

PATIENTS AND METHODS

A search was made in Medline for studies published between 1966 and May 2001 that included >50 children and reported on the frequency of measures of subclinical cardiotoxicity. Information about the studies was abstracted by two reviewers and a validity score was calculated for each study.

RESULTS

The reported frequency of subclinical cardiotoxicity varied between 0% and 57% in the 25 studies included. Differences in outcome definitions of subclinical cardiotoxicity and differences in study patients with respect to the dose of anthracycline seemed to explain part of the wide variance of the frequency of subclinical cardiotoxicity. Fourteen of the 25 studies showed serious methodological limitations.

CONCLUSIONS

The reported frequency of subclinical cardiotoxicity shows a wide variation. Well designed studies with accurate and precise outcome measurements in well described groups of patients, after a sufficiently long follow-up period, are needed to obtain more insight into the frequency and importance of risk factors, and the clinical consequences of anthracycline-related subclinical cardiotoxicity.

Subclinical cardiotoxic effects of anthracyclines as assessed by magnetic resonance imaging-a pilot study

BACKGROUND

Anthracyclines are potent chemotherapeutics burdened by their cardiotoxicity. So far no marker to detect early cardiac damage exists. We tested the ability of magnetic resonance imaging (MRI) to show early changes in myocardial signal and cardiac function after anthracycline therapy.

METHODS

Twenty-two patients with normal cardiac function were investigated by MRI before and 3 and 28 days after anthracycline chemotherapy. Contrast enhanced fast spin echo images were obtained to characterize myocardial enhancement. Left ventricular ejection fraction was measured by MRI in contiguous short-axis planes.

RESULTS

All patients remained clinically stable. Ejection fraction decreased from 67.8% +/- 1.4% to 58.9% +/- 1.9% after 28 days (P < .05). The relative myocardial contrast enhancement increased from 3.8 +/- 0.4 to 6.9 +/- 1.1 (P < .01). An increase of the enhancement of >5 on day 3 compared with baseline predicted a significant loss of ejection fraction at 28 days (67.5% +/- 2.8% to 51.4% +/- 5.6%, mean difference 16.1% +/- 6.6%; P < .05), whereas an increase of +5 was not associated with a significant loss of ejection fraction (67.6% +/- 1.7% to 62.5% +/- 1.4%, mean difference 4.1% +/- 2.6%; P not significant).

CONCLUSIONS

MRI detects early changes in myocardial contrast and slightly deteriorating cardiac function in patients receiving anthracyclines. Larger patient cohorts and longer follow-up are needed to evaluate MRI as a predictor for anthracycline cardiotoxicity.

Prospective Evaluation of Early Cardiac Damage Induced by Epirubicin-Containing Adjuvant Chemotherapy and Locoregional Radiotherapy in Breast Cancer Patients

PURPOSE: To evaluate prospectively the cardiotoxic effects of epirubicin-containing adjuvant chemotherapy in breast cancer patients.

PATIENTS AND METHODS: Patients (median age, 46 years; range, 28 to 55 years) were treated with five cycles of fluorouracil, epirubicin (90 mg/m2), and cyclophosphamide (FEC) (group I, n = 21) or with four cycles of FEC followed by high-dose chemotherapy consisting of cyclophosphamide, thiotepa, and carboplatin (group II, n = 19). Locoregional radiotherapy was applied subsequently. Cardiac evaluation was performed before chemotherapy (T0), 1 month after chemotherapy, 1 month after radiotherapy (T2), and 1 year after start of chemotherapy (T3). Left ventricular ejection fraction (LVEF) was determined by radionuclide ventriculography and diastolic function by echocardiography. Autonomic function was assessed by 24-hour ECG registration for heart rate variability (HRV) analysis. Time-corrected QT (QTc) was assessed and N-terminal atrial natriuretic peptide (NT-ANP) and brain natriuretic peptide (BNP) were measured as biochemical markers of cardiac dysfunction.

RESULTS: No patient developed overt congestive heart failure (CHF) and the mean LVEF declined from 0.61 at T0 to 0.54 at T3 (P = .001), resulting in an LVEF below 0.50 (range, 0.42 to 0.49) in 17% of the patients, whereas 28% had a decline of more than 0.10. Plasma NT-ANP levels increased gradually from 237 pmol/L at T0 to 347 pmol/L at T3 (P < .01), whereas plasma BNP levels increased from 2.9 pmol/L to 5.1 pmol/L (P = .04). Mean QTc increased from 406 msec at T0 to 423 msec at T3 (P < .01). No persistent alterations were found in diastolic function and HRV.

CONCLUSION: Relatively low doses of epirubicin in adjuvant chemotherapy for breast cancer results in mild subclinical myocardial damage demonstrated by a decline in LVEF, an increase in natriuretic peptide levels, and an increase in QTc, which may indicate a long-term risk of CHF.

Mitral regurgitation after anthracycline treatment for childhood malignancy

OBJECTIVE

To investigate the new onset of mitral regurgitation in patients with otherwise normal echocardiograms after anthracycline treatment and to assess its relation to other selected indicators of myocardial damage.

DESIGN

Prospective echocardiographic and electrocardiographic study.

SETTING

Tertiary paediatric cardiac referral centre.

PATIENTS

305 patients, aged 2-33 years (median 14 years), treated with cumulative anthracycline doses of between 150-450 mg/m(2) (median 180 mg/m(2)) for childhood malignancy.

MAIN OUTCOME MEASURES

Colour flow Doppler detection of mitral regurgitation and its relation to changes in echocardiographic indices of left ventricular function (systolic and diastolic dimensions, fractional shortening) and to changes in the 12 lead ECG; and the prevalence of mitral regurgitation in the anthracycline treated patients in comparison with previously studied normal volunteers of similar age.

RESULTS

34 patients (11.6%) developed ultrasound detectable mitral regurgitation, which was not apparent clinically, during or after anthracycline treatment, compared with only 1.8% of a normal population of similar age (p < 0.0001). Nine of the 34 also developed non-specific T wave abnormalities. All 34 patients had normal systolic function at the time of initial detection of mitral regurgitation, but four later developed impaired left ventricular function (5, 11, 20, and 27 months after the first detection of mitral regurgitation).

CONCLUSIONS

Mitral regurgitation occurs much more often in patients treated with anthracyclines than in the normal population. Echocardiographic detection of new mitral regurgitation with or without ECG abnormalities may be an early predictor of anthracycline cardiomyopathy.

Low-dose daunorubicin in induction treatment of childhood acute lymphoblastic leukemia: no long-term cardiac damage in a randomized study of the Dutch Childhood Leukemia Study Group

BACKGROUND

To investigate late cardiotoxicity in childhood acute lymphoblastic leukemia (ALL) survivors after induction treatment with or without daunorubicin (DNR; 25 mg/m(2), i.v., weekly, x4, cumulative dose 100 mg/m(2)).

PROCEDURE

Cardiac function was assessed in 90 event-free survivors of childhood ALL, 11.4-17.8 years (median 14.8 years) after treatment according to the DCLSG protocol ALL V. In this protocol patients were randomized to receive (group B) or not to receive (group A) DNR 25 mg/m(2)/week i.v. during the first 4 weeks of induction treatment. Age at diagnosis was 1.2-14.9 years (median 4.5 years). The cardiac evaluation consisted of a history, physical examination, electrocardiogram (ECG), 24 hr ambulatory ECG, and echocardiography.

RESULTS

Electrocardiographic data, arrhythmias, left ventricular dimensions, left ventricular contractility, wall stress, and diastolic function were within normal limits in both groups. No difference could be shown between data from group A (n = 40) and group B (n = 50).

CONCLUSIONS

No late cardiac damage was demonstrated in childhood ALL survivors after induction treatment including a cumulative dose of 100 mg/m(2) DNR, compared to survivors who received the same treatment but without DNR. DNR 100 mg/m(2) given in 4 doses of 25 mg/m(2)/week appears to be a safe dose in induction treatment of ALL.