Treatment with angiotensin-converting-enzyme inhibitor for epirubicin-induced dilated cardiomyopathy

Research progress on the role and mechanism of Sirtuin family in doxorubicin cardiotoxicity

BACKGROUND

Doxorubicin (DOX) is a widely utilized anthracycline chemotherapy drug in cancer treatment, yet its efficacy is hindered by both short-term and long-term cardiotoxicity. Although oxidative stress, inflammation and mitochondrial dysfunction are established factors in DOX-induced cardiotoxicity, the precise molecular pathways remain elusive. Further exploration of the pathogenesis and identification of novel molecular targets are imperative. Recent studies have implicated the Sirtuins family in various physiological and pathological processes, suggesting their potential in ameliorating DOX-induced cardiotoxicity. Moreover, research on Sirtuins has discovered small-molecule compounds or medicinal plants with regulatory effects, representing a notable advancement in preventing and treating DOX-induced cardiac injury.

PURPOSE

In this review, we delve into the pathogenesis of DOX-induced cardiotoxicity and explore the therapeutic effects of Sirtuins in mitigating this condition, along with the associated molecular mechanisms. Furthermore, we delineate the roles and mechanisms of small-molecule regulators of Sirtuins in the prevention and treatment of DOX-induced cardiotoxicity.

STUDY-DESIGN/METHODS

Data for this review were sourced from various scientific databases (such as Web of Science, PubMed and Science Direct) up to March 2024. Search terms included "Sirtuins," "DOX-induced cardiotoxicity," "DOX," "Sirtuins regulators," "histone deacetylation," among others, as well as several combinations thereof.

RESULTS

Members of the Sirtuins family regulate both the onset and progression of DOX-induced cardiotoxicity through anti-inflammatory, antioxidative stress and anti-apoptotic mechanisms, as well as by maintaining mitochondrial stability. Moreover, natural plant-derived active compounds such as Resveratrol (RES), curcumin, berberine, along with synthetic small-molecule compounds like EX527, modulate the expression and activity of Sirtuins.

CONCLUSION

The therapeutic role of the Sirtuins family in mitigating DOX-induced cardiotoxicity represents a potential molecular target. However, further research is urgently needed to elucidate the relevant molecular mechanisms and to assess the safety and biological activity of Sirtuins regulators. This review offers an in-depth understanding of the therapeutic role of the Sirtuins family in mitigating DOX-induced cardiotoxicity, providing a preliminary basis for the clinical application of Sirtuins regulators in this condition.

Evaluation of Ameliorative Effect of Quercetin and Candesartan in Doxorubicin-Induced Cardiotoxicity

BACKGROUND

Several mechanisms have been explored for the anthracycline myocardial toxicity. These are free-radical generation, myocyte apoptosis, lipid peroxidation, mitochondrial deterioration, and direct repression of muscle-specific gene expression. Adriamycin (Doxorubicin) is a potent anti-cancer agent. Adriamycin in prolonged use is fatal and generates free radicals that lead to dose-dependent cardiac toxicity.

OBJECTIVE

The intent of the study was to explore the protective activity of candesartan and quercetin in cardiomyopathy induced by doxorubicin in rats.

METHODS

To induce cardiac toxicity, rats were intraperitoneally treated with doxorubicin (06 equivalent injections of 2.5 mg/kg, i. p. at 48 hour interval for 02 consecutive weeks to achieve a cumulative dose of 15 mg/kg). Individual and combined oral treatment of candesartan (5 mg/kg/day) and quercetin (10 mg/kg/day) was administered for four weeks.

RESULTS

Following cardiomyopathy, heart/body weight ratio (3.526 × 10^-3), serum creatine kinase (352.4±16.99 IU/L), lactate dehydrogenase (661.7±20.45 IU/L) levels were elevated in addition to altered lipid profile (TC - 118.4±4.25 mg/dL, TG - 263.3±9.99 mg/dL, VLDL - 52.66±1.99 mg/dL, LDL - 52.99±5.80 mg/dL and HDL - 12.78±0.36 mg/dL). The pre-cotreatment of candesartan and quercetin significantly restored the values to normal. The increased level of lipid peroxides (33.12±1.63 µmol/mg protein), serum troponin-T (1.82 ± 0.11 pg/mL) and nitric oxide (13.33±0.73 nmol/mg protein) level along with attenuating antioxidant profile, ie catalase, glutathione and superoxide dismutase (1.43±0.12 nmol/mg protein, 8.48±0.42 nmol/mg protein and 2.09±0.031 U/mg protein) were reversed to normal. Morphometry and histopathologic changes represented a beneficial effect of single and combination pre-cotreatment of drugs which significantly decreases adriamycin cardiac toxicity.

CONCLUSION

The overall result depicts more beneficial and cardioprotective effect of quercetin and candesartan combination as compared to their individual effects in doxorubicin treated animals. Therefore, this combination might be a suitable option to treat the cardiotoxic effect of doxorubicin.

Role of Oxidative Stress in the Mechanisms of Anthracycline-Induced Cardiotoxicity: Effects of Preventive Strategies

Anthracycline-induced cardiotoxicity (AIC) persists as a significant cause of morbidity and mortality in cancer survivors. Although many protective strategies have been evaluated, cardiotoxicity remains an ongoing threat. The mechanisms of AIC remain unclear; however, several pathways have been proposed, suggesting a multifactorial origin. When the central role of topoisomerase 2β in the pathophysiology of AIC was described some years ago, the classical reactive oxygen species (ROS) hypothesis shifted to a secondary position. However, new insights have reemphasized the importance of the role of oxidative stress-mediated signaling as a common pathway and a critical modulator of the different mechanisms involved in AIC. A better understanding of the mechanisms of cardiotoxicity is crucial for the development of treatment strategies. It has been suggested that the available therapeutic interventions for AIC could act on the modulation of oxidative balance, leading to a reduction in oxidative stress injury. These indirect antioxidant effects make them an option for the primary prevention of AIC. In this review, our objective is to provide an update of the accumulated knowledge on the role of oxidative stress in AIC and the modulation of the redox balance by potential preventive strategies.

The Role of Biomarkers in Cardio-Oncology

In the field of cardio-oncology, it is well recognised that despite the benefits of chemotherapy in treating and possibly curing cancer, it can cause catastrophic damage to bystander tissues resulting in a range of potentially of life-threatening cardiovascular toxicities, and leading to a number of damaging side effects including heart failure and myocardial infarction. Cardiotoxicity is responsible for significant morbidity and mortality in the long-term in oncology patients, specifically due to left ventricular dysfunction. There is increasing emphasis on the early use of biomarkers in order to detect the cardiotoxicity at a stage before it becomes irreversible. The most important markers of cardiac injury are cardiac troponin and natriuretic peptides, whilst markers of inflammation such as interleukin-6, C-reactive protein, myeloperoxidase, Galectin-3, growth differentiation factor-15 are under investigation for their use in detecting cardiotoxicity early. In addition, microRNAs, genome-wide association studies and proteomics are being studied as novel markers of cardiovascular injury or inflammation. The aim of this literature review is to discuss the evidence base behind the use of these biomarkers for the detection of cardiotoxicity.

Cardiotoxicity of Anthracyclines

Cardiotoxicity is a feared side effect that may limit the clinical use of anthracyclines. It may indeed affect the quality of life and survival of patients with cancer, regardless of oncological prognosis. This paper provides an overview of anthracycline-induced cardiotoxicity in terms of definition, classification, incidence, risk factors, possible mechanisms, diagnosis, and treatment. We also report effective strategies for preventing cardiotoxicity. In addition, we discuss limiting current approaches, the need for a new classification, and early cardiotoxicity detection and treatment. Probably, anthracycline-induced cardiotoxicity is a continuous phenomenon that starts from myocardial cell injury; it is followed by left ventricular ejection fraction (LVEF) and, if not diagnosed and cured early, progressively leads to symptomatic heart failure. Anthracycline-induced cardiotoxicity can be detected at a preclinical phase. The role of biomarkers, in particular troponins, in identifying subclinical cardiotoxicity and its therapy with angiotensin-converting enzyme inhibitors (mainly enalapril) to prevent LVEF reduction is a recognized and effective strategy. If cardiac dysfunction has already occurred, partial or complete LVEF recovery may still be obtained in case of early detection of cardiotoxicity and prompt heart failure treatment.

Regional practice norms for the care of childhood cancer survivors at risk for cardiomyopathy: A Delphi study

BACKGROUND

Treatment-associated cardiomyopathy is a leading cause of morbidity and mortality for childhood cancer survivors (CCS). As evidence is not available to guide the management of CCS at risk for cardiomyopathy, we aim to describe the collective opinion of regional experts for the care of these patients using a consensus-based Delphi methodology.

PROCEDURE

Nineteen physicians from the New England region who care for CCS treated with cardiotoxic therapy (anthracyclines, thoracic radiation) participated in a Delphi panel querying their management approach, using three rounds of anonymous questionnaires formatted as five clinical scenarios. Consensus ≥ 89% agreement.

RESULTS

The response rate was 100% for the first round and 95% for subsequent rounds. Panelists reached consensus on screening asymptomatic CCS with serial echocardiograms (94%) and electrocardiograms (89%), with some disagreement on frequency during pregnancy (83%). All panelists agreed with exercise promotion, with no restrictions on weight training. Consensus was reached on indications for referrals; cardiology for asymptomatic left ventricular dysfunction (ALVD) (100%) and maternal-fetal medicine for pregnancy (94%). In the scenario of ALVD, there was disagreement on the benefit of additional cardiac testing (50% cardiologists recommended cardiac MRI), and although all panelists endorsed treating with angiotension-converting enzyme (ACE) inhibitors, most adult cardiologists (75%) also recommended therapy with beta blockers, compared with none of the pediatric cardiologists or primary-care physicians.

CONCLUSIONS

Despite a lack of evidence to guide the management of CCS at risk for cardiomyopathy, a panel of regional physicians reached consensus on managing most clinical scenarios. A controversial area requiring further study is the medical management of ALVD.

Protecting the heart in cancer therapy

Recent advances in cancer prevention and management have led to an exponential increase of cancer survivors worldwide. Regrettably, cardiovascular disease has risen in the aftermath as one of the most devastating consequences of cancer therapies. In this work, we define cancer therapeutics-induced cardiotoxicity as the direct or indirect cardiovascular injury or injurious effect caused by cancer therapies. We describe four progressive stages of this condition and four corresponding levels of prevention, each having a specific goal, focus, and means of action. We subsequently unfold this didactic framework, surveying mechanisms of cardiotoxicity, risk factors, cardioprotectants, biomarkers, and diagnostic imaging modalities. Finally, we outline the most current evidence-based recommendations in this area according to multidisciplinary expert consensus guidelines.

Anthracycline-induced cardiotoxicity: A multicenter randomised trial comparing two strategies for guiding prevention with enalapril: The International CardioOncology Society-one trial

BACKGROUND

Troponin changes over time have been suggested to allow for an early diagnosis of cardiac injury ensuing cancer chemotherapy; cancer patients with troponin elevation may benefit of therapy with enalapril. It is unknown whether a preventive treatment with enalapril may further increase the benefit.

METHODS

The International CardioOncology Society-one trial (ICOS-ONE) was a controlled, open-label trial conducted in 21 Italian hospitals. Patients were randomly assigned to two strategies: enalapril in all patients started before chemotherapy (CT; 'prevention' arm), and enalapril started only in patients with an increase in troponin during or after CT ('troponin-triggered' arm). Troponin was assayed locally in 2596 blood samples, before and after each anthracycline-containing CT cycle and at each study visit; electrocardiogram and echocardiogram were done at baseline, and at 1, 3, 6 and 12-month follow-up. Primary outcome was the incidence of troponin elevation above the threshold.

FINDINGS

Of the 273 patients, 88% were women, mean age 51 ± 12 years. The majority (76%) had breast cancer, 3% had a history of hypertension and 4% were diabetic. Epirubicin and doxorubicin were most commonly prescribed, with median cumulative doses of 360 [270-360] and 240 [240-240] mg/m², respectively. The incidence of troponin elevation was 23% in the prevention and 26% in the troponin-triggered group (p = 0.50). Three patients (1.1%) -two in the prevention, one in the troponin-triggered group-developed cardiotoxicity, defined as 10% point reduction of LV ejection fraction, with values lower than 50%.

INTERPRETATION

Low cumulative doses of anthracyclines in adult patients with low cardiovascular risk can raise troponins, without differences between the two strategies of giving enalapril. Considering a benefit of enalapril in the prevention of LV dysfunction, a troponin-triggered strategy may be more convenient.

Medical interventions for treating anthracycline-induced symptomatic and asymptomatic cardiotoxicity during and after treatment for childhood cancer

BACKGROUND

Anthracyclines are frequently used chemotherapeutic agents for childhood cancer that can cause cardiotoxicity during and after treatment. Although several medical interventions in adults with symptomatic or asymptomatic cardiac dysfunction due to other causes are beneficial, it is not known if the same treatments are effective for childhood cancer patients and survivors with anthracycline-induced cardiotoxicity. This review is an update of a previously published Cochrane review.

OBJECTIVES

To compare the effect of medical interventions on anthracycline-induced cardiotoxicity in childhood cancer patients or survivors with the effect of placebo, other medical interventions, or no treatment.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library, 2015, Issue 8), MEDLINE/PubMed (1949 to September 2015), and EMBASE/Ovid (1980 to September 2015) for potentially relevant articles. In addition, we searched reference lists of relevant articles, conference proceedings of the International Society for Paediatric Oncology (SIOP), the American Society of Clinical Oncology (ASCO), the American Society of Hematology (ASH), the International Conference on Long-Term Complications of Treatment of Children & Adolescents for Cancer, and the European Symposium on Late Complications from Childhood Cancer (from 2005 to 2015), and ongoing trial databases (the ISRCTN Register, the National Institutes of Health (NIH) Register, and the trials register of the World Health Organization (WHO); all searched in September 2015).

SELECTION CRITERIA

Randomised controlled trials (RCTs) or controlled clinical trials (CCTs) comparing the effectiveness of medical interventions to treat anthracycline-induced cardiotoxicity with either placebo, other medical interventions, or no treatment.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed the study selection. One review author performed the data extraction and 'Risk of bias' assessments, which another review author checked. We performed analyses according to the guidelines in the Cochrane Handbook for Systematic Reviews of Interventions.

MAIN RESULTS

In the original version of the review we identified two RCTs; in this update we identified no additional studies. One trial (135 participants) compared enalapril with placebo in childhood cancer survivors with asymptomatic anthracycline-induced cardiac dysfunction. The other trial (68 participants) compared a two-week treatment of phosphocreatine with a control treatment (vitamin C, adenosine triphosphate, vitamin E, oral coenzyme Q10) in leukaemia patients with anthracycline-induced cardiotoxicity. Both studies had methodological limitations.The RCT on enalapril showed no statistically significant differences in overall survival, mortality due to heart failure, development of clinical heart failure, and quality of life between treatment and control groups. A post-hoc analysis showed a decrease (that is improvement) in one measure of cardiac function (left ventricular end-systolic wall stress (LVESWS): -8.62% change) compared with placebo (+1.66% change) in the first year of treatment (P = 0.036), but not afterwards. Participants treated with enalapril had a higher risk of dizziness or hypotension (risk ratio 7.17, 95% confidence interval 1.71 to 30.17) and fatigue (Fisher's exact test, P = 0.013).The RCT on phosphocreatine found no differences in overall survival, mortality due to heart failure, echocardiographic cardiac function, and adverse events between treatment and control groups.

AUTHORS' CONCLUSIONS

Only one trial evaluated the effect of enalapril in childhood cancer survivors with asymptomatic cardiac dysfunction. Although there is some evidence that enalapril temporarily improves one parameter of cardiac function (LVESWS), it is unclear whether it improves clinical outcomes. Enalapril was associated with a higher risk of dizziness or hypotension and fatigue. Clinicians should weigh the possible benefits with the known side effects of enalapril in childhood cancer survivors with asymptomatic anthracycline-induced cardiotoxicity.Only one trial evaluated the effect of phosphocreatine in childhood cancer patients with anthracycline-induced cardiotoxicity. Limited data with a high risk of bias showed no significant difference between phosphocreatine and control treatments on echocardiographic function and clinical outcomes.We did not identify any RCTs or CCTs studying other medical interventions for symptomatic or asymptomatic cardiotoxicity in childhood cancer patients or survivors.High-quality studies should be performed.

Cardiotoxicity of anticancer treatments: Epidemiology, detection, and management

Answer questions and earn CME/CNE Cancer and heart disease are the leading causes of morbidity and mortality in the industrialized world. Modern treatment strategies have led to an improvement in the chances of surviving a diagnosis of cancer; however, these gains can come at a cost. Patients may experience adverse cardiovascular events related to their cancer treatment or as a result of an exacerbation of underlying cardiovascular disease. With longer periods of survival, late effects of cancer treatment may become clinically evident years or decades after completion of therapy. Current cancer therapy incorporates multiple agents whose deleterious cardiac effects may be additive or synergistic. Cardiac dysfunction may result from agents that can result in myocyte destruction, such as with anthracycline use, or from agents that appear to transiently affect left ventricular contractility. In addition, cancer treatment may be associated with other cardiac events, such as severe treatment-induced hypertension and vasospastic and thromboembolic ischemia, as well as rhythm disturbances, including QTc prolongation, that may be rarely life-threatening. Early and late effects of chest radiation can lead to radiation-induced heart disease, including pericardial disease, myocardial fibrosis, cardiomyopathy, coronary artery disease, valvular disease, and arrhythmias, in the setting of myocardial fibrosis. The discipline of cardio-oncology has developed in response to the combined decision making necessary to optimize the care of cancer patients, whether they are receiving active treatment or are long-term survivors. Strategies to prevent or mitigate cardiovascular damage from cancer treatment are needed to provide the best cancer care. This review will focus on the common cardiovascular issues that may arise during or after cancer therapy, the detection and monitoring of cardiovascular injury, and the best management principles to protect against or minimize cardiotoxicity during the spectrum of cancer treatment strategies. CA Cancer J Clin 2016;66:309-325. © 2016 American Cancer Society.

Routine Prophylactic Cardioprotective Therapy Should Not Be Given to All Recipients of Potentially Cardiotoxic Cancer Chemotherapy

With growing recognition of the associations between cancer therapy and cardiotoxicity, attention has increasingly focused on the prevention of cancer therapy-related cardiovascular disease. Various strategies for cardioprotection have been proposed, including routine administration of therapies such as inhibitors of the renin-angiotensin-aldosterone system and β-blockers. We argue this approach is unsupported by the evidence and will be associated with a high likelihood of adverse effects. We highlight alternate strategies for managing this emerging issue, which focus on a targeted approach to primary prevention driven by early identification of cardiotoxicity and selective prophylaxis of patients at increased risk for developing cardiotoxicity.

The Disappearing Sperms: Analysis of Reports Published Between 1980 and 2015

Reports regarding the changes in sperm concentration in different counties of the world are inconsistent. Furthermore, the reports that sprung up from specific epidemiological and experimental examinations did not include data of prior studies or geographical variations. The current study, following a previous report of massive fall in semen volume over the past 33 years, attempts to delineate the trend of altering sperm concentrations and factors responsible for this by reviewing article published from 1980 to July 2015 with geographic differences. The current study identified an overall 57% diminution in mean sperm concentration over the past 35 years ( r = -.313, p = .0002), which, when analyzed for each geographical region, identified a significant decline in North America, Europe, Asia, and Africa. An increasing trend of sperm concentration was identified only in Australia. The association of male age with such a trend ( R² = .979) is reported. The authors also correlated male fertility with sperm concentration. Thus, this comprehensive, evidence-based literature review aims to concisely and systematically present the available data on sperm concentration from 1980 to 2015, as well as to statistically analyze the same and correlate male health with the declining pattern of sperm count in a single scientific review to serve the scientific research zone related to reproductive health. It points to the threat of male infertility in times ahead.

Use of biomarkers for the assessment of chemotherapy-induced cardiac toxicity

OBJECTIVES

To review the evidence for the use of various biomarkers in the detection of chemotherapy associated cardiac damage.

DESIGN AND METHODS

Pubmed.gov was queried using the search words chemotherapy and cardiac biomarkers with the filters of past 10years, humans, and English language. An emphasis was placed on obtaining primary research articles looking at the utility of biomarkers for the detection of chemotherapy-mediated cardiac injury.

RESULTS

Biomarkers may help identify patients undergoing treatment who are at high risk for cardiotoxicity and may assist in identification of a low risk cohort that does not necessitate continued intensive screening. cTn assays are the best studied biomarkers in this context and may represent a promising and potentially valuable modality for detecting cardiac toxicity in patients undergoing chemotherapy. Monitoring cTnI levels may provide information regarding the development of cardiac toxicity before left ventricular dysfunction becomes apparent on echocardiography or via clinical symptoms. A host of other biomarkers have been evaluated for their utility in the field of chemotherapy related cardiac toxicity with intermittent success; further trials are necessary to determine what role they may end up playing for prediction and prognostication in this setting.

CONCLUSIONS

Biomarkers represent an exciting potential complement or replacement for echocardiographic monitoring of chemotherapy related cardiac toxicity which may allow for earlier realization of the degree of cardiac damage occurring during treatment, creating the opportunity for more timely modulation of therapy.

Cardiomyopathy associated with cancer therapy

Chemotherapy-associated cardiomyopathy is a well known cardiotoxicity of contemporary cancer treatment and a cause of increasing concern for both cardiologists and oncologists. As cancer outcomes improve, cardiovascular disease has become a leading cause of morbidity and mortality among cancer survivors. Asymptomatic or symptomatic left ventricular systolic dysfunction in the setting of cardiotoxic chemotherapy is an important entity to recognize. Early diagnosis of cardiac injury through the use of novel blood-based biomarkers or noninvasive imaging modalities may allow for the initiation of cardioprotective medications or modification of chemotherapy regimen to minimize or prevent further damage. Several clinical trials are currently underway to determine the efficacy of cardioprotective medications for the prevention of chemotherapy-associated cardiomyopathy. Implementing a strategy that includes both early detection and prevention of cardiotoxicity will likely have a significant impact on the overall prognosis of cancer survivors. Continued coordination of care between cardiologists and oncologists remains critical to maximizing the oncologic benefit of cancer therapy while minimizing any early or late cardiovascular effects.

Left ventricular endocardial dysfunction in patients with preserved ejection fraction after receiving anthracycline

BACKGROUND

Anthracycline chemotherapy generates progressive dose-dependent left ventricular (LV) dysfunction associated with a poor prognosis. Early detection of minor LV myocardial dysfunction caused by the cardiotoxicity of anthracycline is thus important for predicting global LV dysfunction.

METHODS

Fifty patients with preserved ejection fraction (all ≥55%) after receiving anthracycline chemotherapy were recruited for this study. Two-dimensional speckle tracking was used to assess global radial and circumferential strains from mid-LV short-axis views and global longitudinal strain from the apical four- and two-chamber view as peak global strain curves. Three-dimensional (3D) radial, circumferential, and longitudinal myocardial function was quantified as a peak global strain curve using 3D speckle tracking from all 16 LV segments. 3D speckle tracking imaging was used to evaluate LV endocardial area change ratio (area strain) quantified as peak global area strain curve (3D-GAS) to determine LV endocardial function. Twenty age-, gender-, and EF-matched normal volunteers were studied for comparisons.

RESULTS

Only 3D-GAS and peak 3D global circumferential strains of the anthracycline group were significantly worse than those of the control group (-43.3 ± 3.1 vs. -45.8 ± 4.3% and -31.6 ± 3.5% vs. -34.4 ± 4.2%, respectively; P = 0.008, P = 0.004) even though global LV systolic and diastolic functions were similar. 3D-GAS correlated significantly with the cumulative doxorubicin dose (r = 0.316, P = 0.026). It was noteworthy that multivariate analysis showed only 3D-GAS (β = 0.323, P = 0.025) was independently associated with cumulative doxorubicin dose.

CONCLUSIONS

Three-dimensional speckle tracking area strain was found useful for early detection of minor LV endocardial dysfunction associated with the use of anthracycline, and may thus prove to be clinically useful for predicting global LV dysfunction.

Enalaprilat increases PPARβ/δ expression, without influence on PPARα and PPARγ, and modulate cardiac function in sub-acute model of daunorubicin-induced cardiomyopathy

Anthracycline therapy is limited by a cardiotoxicity that may eventually lead to chronic heart failure which is thought to be prevented by ACE inhibitors (ACEi). However, the protective effect of ACEi in early stages of this specific injury remains elusive. Activated nuclear transcription factors peroxisome proliferator-activated receptors (PPAR) regulate cellular metabolism, but their involvement in anthracycline cardiomyopathy has not been investigated yet. For this purpose, Wistar rats were administered with daunorubicin (i.p., 3 mg/kg, in 48 h intervals) or co-administered with daunorubicine and enalaprilat (i.p., 5 mg/kg in 12 h intervals). Control animals received vehicle. Left ventricular function was measured invasively under anesthesia. Cell-shortening was measured by videomicroscopy in isolated cardiomyocytes. Expression of PPARs mRNA in cardiac tissue was measured by Real-Time PCR. Although the hemodynamic parameters of daunorubicin-treated rats remained altered upon ACEi co-administration, ACEi normalized daunorubicin-induced QT prolongation. On cellular level, ACEi normalized altered basal and isoproterenol-stimulated cardiac cell shortening in daunorubicine-treated group. Moreover, anthracycline administration significantly up-regulated heart PPARα mRNA and its expression remained increased after ACEi co-administration. On the other hand, the expression of cardiac PPARβ/δ was not altered in anthracycline-treated animals, whereas co-administration of ACEi increased its expression. Conclusively, effect of ACEi can be already detected in sub-acute phase of anthracycline-induced cardiotoxicity. Altered expression of heart PPARs may suggest these nuclear receptors as a novel target in anthracycline cardiomyopathy.

Left ventricular assist device as bridge to recovery for anthracycline-induced terminal heart failure

Anthracycline treatments are hampered by dose-related cardiotoxicity, frequently leading to heart failure (HF) with a very poor prognosis. The authors report a case of a 19-year-old man developing HF after anthracycline treatment for Ewing sarcoma. Despite medical treatment, his condition deteriorated to terminal HF, leading to implantation of a mechanical left ventricular assist device (LVAD). His heart function recovered, allowing explantation of the device 14 months after implantation. Heart transplantation is often contraindicated in the first years after treatment for cancers, and LVAD as "bridge to recovery" may be warranted in similar patients.

Management of chemotherapy induced cardiomyopathy

Chemotherapy related cardiac dysfunction (CRCD) is a serious complication of anticancer therapy. CRCD can be classified into two types. Type I CRCD is exemplified by anthracyline- induced cardiac dysfunction and type II CRCD is exemplified by trastuzumab- induced cardiac dysfunction. The mechanism of cardiac toxicity in both types is not well defined. Certain risk factors may play a role in developing the cardiac injury, most importantly, the cumulative dose when dealing with anthracycline induced cardiotoxicity. Establishing an early diagnosis and initiating early treatment may be an important step in preventing irreversible cardiac injury especially in type I CRCD. Currently there are no guidelines developed specifically for the treatment of chemotherapy induced cardiomyopathy (CIC), however a few small studies support the use of neurohormonal antagonists in the treatment and prevention of CIC. Large multi- centers trials are needed to establish guidelines for CIC. Until then, we advocate following the American College of Cardiology/ American Heart Association (ACC/AHA) and Heart Failure Society of America (HFSA) guidelines. Additionally, a close collaboration between the patient's cardiologist and oncologist is strongly recommended in order to establish a long term plan for the patient.

Medical interventions for treating anthracycline-induced symptomatic and asymptomatic cardiotoxicity during and after treatment for childhood cancer

BACKGROUND

Anthracyclines are frequently used chemotherapeutic agents for childhood cancer that can cause cardiotoxicity during and after treatment. Although several medical interventions in adults with symptomatic or asymptomatic cardiac dysfunction due to other causes are beneficial, it is not known if the same treatments are effective for childhood cancer patients and survivors with anthracycline-induced cardiotoxicity.

OBJECTIVES

To compare the effect of medical interventions on anthracycline-induced cardiotoxicity in childhood cancer patients or survivors with the effect of placebo, other medical interventions or no treatment.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, 2011, issue 1), MEDLINE/PubMed (1949 to May 2011) and EMBASE/Ovid (1980 to May 2011) for potentially relevant articles. We additionally searched reference lists of relevant articles, conference proceedings and ongoing trial databases.

SELECTION CRITERIA

Randomised controlled trials (RCTs) or controlled clinical trials (CCTs) comparing the effectiveness of medical interventions to treat anthracycline-induced cardiotoxicity with either placebo, other medical interventions or no treatment.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed the study selection. One review author performed the data extraction and 'Risk of bias' assessments which were checked by another review author.

MAIN RESULTS

We identified two RCTs. One trial (135 patients) compared enalapril with placebo in childhood cancer survivors with asymptomatic anthracycline induced cardiac dysfunction. The other trial (68 patients) compared a two-week treatment of phosphocreatine with a control treatment (vitamin C, ATP, vitamin E, oral coenzyme Q10) in leukaemia patients with anthracycline-induced cardiotoxicity. Both studies had methodological limitations.The RCT on enalapril showed no (statistically) significant differences in overall survival, mortality due to heart failure, development of clinical heart failure and quality of life between treatment and control group. A post-hoc analysis showed a decrease (i.e. improvement) in one measure of cardiac function (left ventricular end systolic wall stress (LVESWS): -8.62% change) compared with placebo (+1.66% change) in the first year of treatment (P = 0.036), but not afterwards. Patients treated with enalapril had a higher risk of dizziness or hypotension (RR 7.17, 95% CI 1.71 to 30.17) and fatigue (Fisher's exact test, P = 0.013).The RCT on phosphocreatine found no differences in overall survival, mortality due to heart failure, echocardiographic cardiac function and adverse events between treatment and control group.

AUTHORS' CONCLUSIONS

For the effect of enalapril in childhood cancer survivors with asymptomatic cardiac dysfunction, only one RCT is available. Although there is some evidence that enalapril temporarily improves one parameter of cardiac function (LVESWS), it is unclear whether it improves clinical outcomes. Enalapril was associated with a higher risk of dizziness or hypotension and fatigue. Clinicians should weigh the possible benefits with the known side-effects of enalapril in childhood cancer survivors with asymptomatic anthracycline-induced cardiotoxicity.For the effect of phosphocreatine in childhood cancer patients with anthracycline-induced cardiotoxicity, only one RCT is available. Limited data with a high risk of bias showed no significant difference between phosphocreatine and control treatment on echocardiographic function and clinical outcomes.We did not identify any RCTs or CCTs studying other medical interventions for symptomatic or asymptomatic cardiotoxicity in childhood cancer patients or survivors.High-quality studies should be performed.

Prevention and treatment of cardiomyopathy and heart failure in patients receiving cancer chemotherapy

Chemotherapy (CT)-induced cardiotoxicity remains an unresolved problem that strongly affects the quality of life and overall survival of cancer patients. The most typical form of cardiotoxicity, a dilated cardiomyopathy (CMP), usually becomes manifest late in the course of the disease and is classically considered to be refractory to therapy. Preventing cardiotoxicity remains the most important strategy, and several measures have been proposed, including cardiac function monitoring, limitation of CT dose, use of anthracycline analogues and cardioprotectants, and early detection of cardiotoxicity by biomarkers. The response to modern heart failure therapy of CT-induced CMP has never been evaluated in clinical trials, and no definite guidelines have been adopted. Although it is likely that medications used for other forms of CMP, particularly angiotensin-converting enzyme inhibitors and beta-blockers, may be highly effective, there is still some unjustified concern regarding their use in cancer patients.

Protective effects of aliskiren in doxorubicin-induced acute cardiomyopathy in rats

In this study, effect of aliskiren (ALK) on doxorubicin (DXR)-induced cardiomyopathy in rats was evaluated. ALK (50 and 100 mg/kg/day) was administered for 7 days and a single intraperitoneal injection of DXR (20 mg/kg) on day 5. The animals were sacrificed 48 h after DXR administration. DXR produced significant elevation in malondialdehyde (MDA) and significantly inhibited the activity of glutathione (GSH) in heart tissue, with a significant rise in the serum levels of lactate dehydrogenase (LDH), total cholesterol (TC), triglycerides (TG), low-density lipoprotein (LDL) and reduction in high-density lipoprotein (HDL), indicating acute cardiac toxicity. ALK pretreatment significantly reduced the MDA concentration and ameliorated the inhibition of cardiac GSH activity. ALK also significantly improved the serum levels of LDH, TC, TG, LDL and reduction in HDL in DXR-treated rats. Furthermore, histological examination of the heart sections confirmed the myocardial injury with DXR administration and the near-normal pattern with ALK pretreatment. The results provide clear evidence that the ALK pretreatment offered significant protection against DXR-induced enzymatic changes and cardiac tissue damage.

Anthracycline-induced cardiomyopathy: clinical relevance and response to pharmacologic therapy

OBJECTIVES

The purpose of this study was to evaluate the clinical relevance of anthracycline-induced cardiomyopathy (AC-CMP) and its response to heart failure (HF) therapy.

BACKGROUND

The natural history of AC-CMP, as well as its response to modern HF therapy, remains poorly defined. Hence, evidence-based recommendations for management of this form of cardiomyopathy are still lacking.

METHODS

We included in the study 201 consecutive patients with a left ventricular ejection fraction (LVEF) <or=45% due to AC-CMP. Enalapril and, when possible, carvedilol were promptly initiated after detection of LVEF impairment. LVEF was measured at enrollment, every month for the first 3 months, every 3 months during the first 2 following years, and every 6 months afterward (mean follow-up 36 +/- 27 months). Patients were considered responders, partial responders, or nonresponders according to complete, partial, or no recovery in LVEF, respectively. Major adverse cardiac events during follow-up were also evaluated.

RESULTS

Eighty-five patients (42%) were responders; 26 patients (13%) were partial responders, and 90 patients (45%) were nonresponders. The percentage of responders progressively decreased as the time from the end of chemotherapy to the start of HF treatment increased; no complete recovery of LVEF was observed after 6 months. Responders showed a lower rate of cumulative cardiac events than partial and nonresponders (5%, 31%, and 29%, respectively; p < 0.001).

CONCLUSIONS

In cancer patients developing AC-CMP, LVEF recovery and cardiac event reduction may be achieved when cardiac dysfunction is detected early and a modern HF treatment is promptly initiated.

Cardio-oncology: a new medical issue

Due to the increasing number of long-term cancer survivors, the ageing of the population, as well as the increased incidence and prevalence of oncologic and cardiovascular diseases, the number of patients presenting oncologic and cardiologic co-morbidities are increasing. Accordingly, there is a rapidly growing need for a comprehensive and proficient management of patients in whom the two co-morbidities exist, and for cancer patients whose clinical history and oncologic treatment put them at higher risk for developing cardiovascular problems, in order to provide the optimal treatment in every situation, and to avoid the possibility that the development of the second disease does not lead to a reduction of therapeutic opportunities for the patient. A new discipline, cardio-oncology, has been created to deal with this need. Its aim is to investigate new strategies, collect new evidence-based indications and develop interdisciplinary expertise in order to manage this growing category of patients. Cardio-oncology deals with the following main clinical and research areas: early diagnosis of cardiotoxicity, risk stratification and preventions, treatment and monitoring of cardiotoxicity.

Prevention of high-dose chemotherapy-induced cardiotoxicity in high-risk patients by angiotensin-converting enzyme inhibition

BACKGROUND

An increase in troponin I soon after high-dose chemotherapy (HDC) is a strong predictor of poor cardiological outcome in cancer patients. This finding has important clinical implications and provides a rationale for the development of prophylactic strategies for preventing cardiotoxicity. Angiotensin-converting enzyme inhibitors slow the progression of left ventricular dysfunction in different clinical settings, but their role in the prevention of cardiotoxicity has never been investigated.

METHODS AND RESULTS

Of the 473 cancer patients evaluated, 114 (72 women; mean age, 45+/-12 years) who showed a troponin I increase soon after HDC were randomized to receive (angiotensin-converting enzyme inhibitor group; 20 mg/d; n=56) or not to receive (control subjects; n=58) enalapril. Treatment was started 1 month after HDC and continued for 1 year. Cardiological evaluation was performed at baseline and at 1, 3, 6, and 12 months after HDC. The primary end point was an absolute decrease >10 percent units in left ventricular ejection fraction, with a decline below the normal limit value. A significant reduction in left ventricular ejection fraction and an increase in end-diastolic and end-systolic volumes were observed only in untreated patients. According to the Kaplan-Meier analysis, the incidence of the primary end point was significantly higher in control subjects than in the angiotensin-converting enzyme inhibitor group (43% versus 0%; P<0.001).

CONCLUSIONS

In high-risk, HDC-treated patients, defined by an increased troponin I value, early treatment with enalapril seems to prevent the development of late cardiotoxicity.

Anthracycline cardiotoxicity

The use of anthracyclines is limited by dose-dependent cardiotoxicity. Three forms of anthracycline cardiotoxicity are described; an immediate pericarditis-myocarditis syndrome, an early onset chronic progressive CHF developing during or shortly after therapy and late-onset cardiotoxicity presenting years following treatment. A number of risk factors have been reported, including; cumulative dose, administration schedule, mediastinal radiotherapy, old and young age, concurrent cardiovascular disease, combination therapy, gender, ethnicity and chromosomal abnormalities. Evaluation of left ventricular ejection fraction has been widely adopted as a means of monitoring and assessing anthracycline-induced cardiotoxicity. Biochemical markers and other techniques, such as endomyocardial biopsy, metaiodobenzylguanidine and indium-111-antimyosin scintigraphy are not routinely used. Methods employed to prevent cardiotoxicity include cumulative dose limitation, alteration of administration schedule, anthracycline analogues, liposomal formulations and the cardioprotective agent, dexrazoxane. With the growing number of paediatric malignancy survivors and the increasing use of anthracyclines in the adjuvant treatment of breast cancer, the cardiotoxicity associated with these agents will remain a formidable issue for physicians. Further work is required to identify patients at increased risk of cardiotoxicity and to develop novel methods of protecting and treating this adverse effect.

Cardiotoxic Consequences of Anthracycline-Containing Therapy in Patients With Breast Cancer

In women, breast cancer is the second most common form of cancer and the leading cause of death caused by malignancy. The anthracycline antibiotics are potent anti-tumor agents used in a wide spectrum of malignancies. They are part of the gold standard adjuvant therapy for breast cancer and in metastatic disease they provide significant increases in response rate, time to disease progression, and overall survival. The addition of trastuzumab augments the effects of anthracycline-based therapy in both the adjuvant and metastatic settings. The successful use of anthracyclines is, however, restricted by the risk of developing life-threatening congestive heart failure. This risk increases exponentially with cumulative dose, and is further augmented by the addition of trastuzumab. Studies have reported that 10% to 26% of patients administered cumulative anthracycline doses above those recommended (> or =500 mg/m2 for doxorubicin and 1,000 mg/m2 for epirubicin) develop congestive heart failure, and that more than 50% of patients administered these doses will experience measurable functional impairment months to years after the end of therapy. The susceptibility of patients to anthracycline-induced cardiotoxicity varies widely, with a dramatic increase with advancing age. The onset of clinical and subclinical cardiac damage is delayed and occurs more than 3 months after the cessation of treatment, indicating a crucial time for functional impairment to occur and highlighting the ineffectiveness of monitoring left ventricular ejection fraction as an endpoint during anthracycline therapy. Possible future treatment options for managing anthracycline-induced cardiotoxicity include agents such as dexrazoxane that prevent oxygen-free radical generation. Further investigation is required into the use of angiotensin-converting enzyme inhibitors to redress cardiac damage and new methods of identifying patients at high risk of congestive heart failure before cardiac damage has occurred.

Anthracycline-induced cardiotoxicity in children with cancer: strategies for prevention and management

The fact that anthracyclines are cardiotoxic seriously narrows their therapeutic index in cancer therapy. The cardiotoxic risk increases with the cumulative dose and may lead to congestive heart failure (CHF) and dilated cardiomyopathy in adults and in children. The prevention of anthracycline-induced cardiotoxicity is particularly important in children who can be expected to survive for decades after being cured of their malignancy. Attempts to reduce anthracycline cardiotoxicity have been directed towards: (i) decreasing myocardial concentrations of anthracyclines and their metabolites by dose limitation and schedule modification; (ii) developing less cardio-toxic analogs; and (iii) concurrently administering cardioprotective agents to attenuate the effects of anthracyclines on the heart. As regards schedule modification, avoidance of anthracycline peak levels may reduce the pathologic and clinical cardiotoxicity, although this has not always been observed. The analogs of doxorubicin, such as idarubicin and epirubicin, have similar cardiotoxicity to that of doxorubicin when given in amounts of equivalent myelotoxicity. Liposomal anthracyclines are a new class of agents that may permit more specific organ targeting, thereby producing less systemic and cardiac toxicity, but more studies are required to assess the advantages, if any, of these preparations over classical anthracyclines. The cardioprotective agent, dexrazoxane, an iron chelator, is highly effective and provides short-term cardioprotection to most patients receiving even the most intensive doxorubicin-containing regimens. Its long-term benefits remain to be determined. In addition, data remain insufficient to make specific recommendations regarding current use of dexrazoxane in children. It is thought that subtle abnormalities, related to anthracycline treatment in childhood, can develop into more permanent myocardial disease resulting in cardiomyopathy, which may progress to CHF. As regards the therapy of patients with anthracycline cardiotoxicity, two different situations have, therefore, to be considered: (i) if the patient presents with cardiac abnormalities, such as a reduction in fractional shortening at echocardiogram, without cardiac symptoms; and (ii) if the patient has CHF. In the presence of CHF, recovery with digitalis-diuretic therapy alone seldom occurs, and in patients who have refractory hemodynamic decompensation, heart transplantation is indicated. In patients with CHF, therapy with ACE inhibitors induces improvement in left ventricular structure and function, but this improvement is transient. Randomized clinical trials are, therefore, necessary to determine the effects of ACE inhibitors in mild-to-moderate left ventricular dysfunction. The beneficial effects of beta-adrenoceptor antagonists (beta-blockers) on cardiac function in heart failure due to anthracyclines seem comparable with those observed in other forms of heart failure with systolic dysfunction. Many drugs are available to treat children with CHF due to anthracycline treatment, but they are only palliative.

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.

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.

The role of nitric oxide in anthracycline toxicity and prospects for pharmacologic prevention of cardiac damage

Anthracycline antibiotics are potent antitumor agents whose activity is severely limited by a cumulative dose-dependent chronic cardiotoxicity that results from the summation of multiple biochemical pathways of cellular damage, which ultimately yields to disruption of myocardiocyte integrity and loss of cardiac function. Nitric oxide (NO) is a key molecule involved in the pathophysiology of heart; dysregulation of activity of NO synthases (NOSs) and of NO metabolism seems to be a common feature in various cardiac diseases. The contribution of NO to anthracycline cardiac damage is suggested by evidence demonstrating anthracycline-mediated induction of NOS expression and NO release in heart and the ability of NOSs to promote anthracycline redox cycling to produce reactive oxygen species (ROS), including O2-* and H2O2. Overproduction of ROS and NO yields to reactive nitrogen species, particularly the powerful oxidant molecule peroxynitrite (ONOO-), which may produce the marked reduction of cardiac contractility. This review focuses on the anthracycline-mediated deregulation of NO network and presents an unifying viewpoint of the main molecular mechanisms involved in the pathogenesis of anthracycline cardiotoxicity, including iron, free radicals, and novel mechanistic notions on cardiac ceramide signaling and apoptosis. The data presented in the literature encourage the development of strategies of pharmacological manipulation of NO metabolism to be used as a novel approach to the prevention of cardiotoxicity induced by anthracyclines.

Successful Allogeneic Bone Marrow Transplantation for Acute Myelogenous Leukemia after Drug-Induced Cardiomyopathy

Anthracycline derivatives often induce cardiomyopathy. Patients with seriously decreased cardiac function due to chemotherapeutic drugs cannot usually receive allogeneic hematopoietic stem cell transplantation (SCT) for hematologic disorders. We successfully performed allogeneic bone marrow transplantation (BMT) in a patient with severe cardiomyopathy. An 18-year-old woman with relapsed acute myelogenous leukemia had cardiomyopathy due to previous anthracycline administration. She underwent allogeneic BMT from her HLA-identical brother. Her preconditioning regimen was cytosine arabinoside, etoposide, total body irradiation, and high-dose cyclophosphamide. Congestive heart failure (CHF) was not present before BMT. Right heart pressures were monitored by a pulmonary arterial balloon catheter system (Swan-Ganz catheter). After BMT, she had severe CHF, which was controlled using pimobendan and amrinone. Patients with cardiomyopathy can receive allogeneic SCT under strict hemodynamic management.

Long-term enalapril therapy for left ventricular dysfunction in doxorubicin-treated survivors of childhood cancer

PURPOSE

A common late effect of doxorubicin therapy for childhood cancer is reduced left-ventricular (LV) wall thickness resulting in elevated LV afterload and depressed LV function. Many children are given angiotensin-converting enzyme inhibitors, which have been studied primarily in adults. We document the long-term effects of angiotensin-converting enzyme inhibitors in doxorubicin-treated survivors of childhood cancer.

PATIENTS AND METHODS

In this retrospective study, we reviewed records of 18 children who had regular echocardiographic examinations during enalapril therapy (mean age at cancer diagnosis, 8 years; mean time between completion of doxorubicin therapy and start of enalapril, 7 years; median follow-up since the start of enalapril, 10 years).

RESULTS

Over the first 6 years of enalapril therapy, there was progressive improvement toward normal values in LV dimension, afterload, fractional shortening, and mass, but all these parameters deteriorated between 6 and 10 years. LV wall thickness deteriorated throughout the study period, as did LV contractility and systolic blood pressure. Diastolic blood pressure fell slightly. By 6 years on enalapril, all six patients who had had congestive heart failure at the start of enalapril therapy had either died or undergone cardiac transplantation, compared with three of the 12 asymptomatic patients.

CONCLUSION

In doxorubicin-treated long-term survivors of childhood cancer, enalapril-induced improvement in LV structure and function is transient. The primary defect, which is LV wall thinning, continues to deteriorate, and thus the short-term improvement was mostly related to lowered diastolic blood pressure.

Functional monitoring of anthracycline cardiotoxicity: a prospective, blinded, long-term observational study of outcome in 120 patients

BACKGROUND

With increasing doses the highly tumoricidal anthracycline drugs cause heart damage. Based on empirical drug limitations about 10-15% of patients will develop congestive heart failure (CHF) with a mortality of -50% within 2 years on digitalo-diuretic therapy alone. To avoid CHF there is a consensus recommendation that cardiac function should be monitored in close connection with anthracycline administration. As no prospective studies in a larger series have been performed, these recommendations are based on retrospective data on small numbers of patients.

PATIENTS AND METHODS

In a prospective, blinded observational study 120 patients with advanced breast cancer were followed before, during, and a median 3 years after treatment with epirubicin. They had 604 serial radionuclide measurements of left ventricular ejection fraction (LVEF) that were stored without calculations except in patients who developed a well-defined CHF.

RESULTS

Anthracycline cardiotoxicity was closely correlated with the cumulative dose, with a great variability in individual susceptibility and a dramatic increase with advancing age. With a delayed onset of 3 months or more, epirubicin induced a threatening, slowly progressive deterioration of cardiac function continuing years after treatment. An actuarial estimation of 59% of the patients experienced a 25% relative reduction in LVEF 3 years after 850-1000 mg/m2 of epirubicin and 20% had deteriorated into a CHF. The patients did not spontaneously regain cardiac function whereas continued therapy with a circadian angiotensin-converting enzyme inhibitor for more than 3 months caused a remarkably potent and long-lasting recovery.

CONCLUSIONS

Due to the displaced cardiotoxic manifestation, functional monitoring in close connection with anthracycline administration appears to be a poorly effective method while later monitoring is essential. Current monitoring recommendations should therefore be revised.

Cardioprotective effects of zofenopril, a new angiotensin-converting enzyme inhibitor, on doxorubicin-induced cardiotoxicity in the rat

We have studied the effect of zofenopril, a new angiotensin-converting enzyme inhibitor in preventing cardiac injury induced by chronic doxorubicin treatment in rats. Cardiac function was assessed by measuring changes in electrocardiogram (ECG) tracings, haemodynamics and cardiac responses in vivo to isoprenaline, 4 weeks after suspension of doxorubicin treatment, in vehicle-treated rats and in animals receiving zofenopril (15 mg/kg/os/day) alone, doxorubicin (1.5 mg/kg i.v. once a week for 5 weeks) or zofenopril+doxorubicin treatment. Doxorubicin induced a significant lengthening of the QalphaT interval, which was completely prevented by zofenopril treatment. The cardiac positive inotropic effect induced by i.v. isoprenaline was selectively depressed by doxorubicin (no changes in chronotropic responses) and this adverse effect of doxorubicin was also prevented in zofenopril+doxorubicin pretreated rats. Doxorubicin induced a significant increase in relative heart weight, which was likewise prevented in zofenopril+doxorubicin treated rats. In separate experiments, zofenopril did not interfere with the antitumor activity of doxorubicin (inhibition of tumor growth in nude mice xenografted with A2780 human tumor line). In conclusion, the oral administration of zofenopril is able to significantly ameliorate, up to 4 weeks after the end of doxorubicin administration, doxorubicin-induced cardiotoxicity without affecting the antitumor activity of this anthracycline.

Anthracycline-induced cardiomyopathy: long-term effects on myocardial cell integrity, cardiac adrenergic innervation and fatty acid uptake

Cardiotoxicity of anthracyclines is a clinical challenge in cancer chemotherapy. Limited data is available on the physiological mechanisms responsible for anthracycline-induced heart failure or its recovery. We studied four patients with a history of severe anthracycline-induced heart failure manifested 2-116 months earlier by using radionuclide ventriculography for the measurement of left ventricular function, indium-111-antimyosin scintigraphy for the detection of myocardial cell injury and iodine-123-metaiodobenzylguanidine (MIBG) scintigraphy for the assessment of cardiac adrenergic innervation. Myocardial perfusion and fatty acid utilization were assessed with iodine-123-paraphenyl pentadecanoid acid (pPPA) and single photon emission computed tomography (SPECT). Symptoms of congestive heart failure (CHF) were still present in two patients whereas the others were asymptomatic at the time of the study. The patients who showed complete clinical recovery had normal or near normal left ventricular ejection fraction (LVEF) (47 and 52%), whereas the patients with symptoms of heart failure had low ejection fractions (21 and 31%). All patients presented with abnormal antimyosin uptake and decreased myocardial MIBG uptake. Patients with low ejection fraction tended to have higher antimyosin uptake suggesting more severe, persistent myocyte injury. All but one patient showed normal fatty acid utilization. These data suggest that patients with a history of severe anthracycline-induced cardiomyopathy have persistent myocardial cell injury and adrenergic dysfunction up to 10 years after the development of heart failure. These findings seem to be present regardless of recovery of left ventricular function.

Prevention of doxorubicin (adriamycin)-induced cardiomyopathy by simultaneous administration of angiotensin-converting enzyme inhibitor assessed by acoustic densitometry

The purpose of our study has to determine the myocardial protective effects of the angiotensin-converting enzyme (ACE) inhibitor temocapril (TEM, 7 mg/kg/day) simultaneously administered with doxorubicin (Adriamycin). Twenty male Sprague-Dawley rats were intraperitoneally administered a cumulative dose of 15 mg/kg of doxorubicin (each dose of 1.0 mg/kg x 15) for 3 weeks, and divided into TEM-untreated and -treated rats. Seven control rats were injected with saline intraperitoneally. Body weight, hemodynamics, and echocardiographic measurements including quantitative analysis of ultrasonic integrated backscatter (IB) were obtained for 12 weeks after treatment. Finally, rats were killed for histopathologic study. At 6 weeks, end-diastolic left ventricular diameter (LVD) and percentage fractional shortening (%FS) were similar in TEM-treated and TEM-untreated rats, but cyclic variation of IB (dB) significantly decreased in TEM-untreated rats (7.3 +/- 1.2; control rats, 9.7 +/- 0.9; p < 0.01). At 12 weeks, %FS decreased in TEM-untreated rats (26.1 +/- 6.1%: TEM-treated rats, 34.2 +/- 6.2; p < 0.05), and calibrated IB (dB) in TEM-untreated rats (15.5 +/- 0.5) increased as compared with that in TEM-treated rats (12.1 +/- 0.7; p < 0.01). Interstitial collagen accumulation increased in TEM-untreated rats and was inhibited in treated rats. Simultaneous administration of TEM with doxorubicin was beneficial in preventing doxorubicin-induced myocardial damage, and myocardial tissue characterization was useful for the early detection of myocardial damage and the assessment of therapy.

Potential contribution of a novel antifibrotic factor, hepatocyte growth factor, to prevention of myocardial fibrosis by angiotensin II blockade in cardiomyopathic hamsters

BACKGROUND

Because hepatocyte growth factor (HGF) prevented and/or regressed fibrosis in liver and pulmonary injury models, HGF may play an important role in the pathogenesis of fibrotic cardiovascular disease. Because angiotensin (Ang) II significantly decreased local HGF production, we performed (1) in vitro experiments using fibroblasts and (2) administration of an ACE inhibitor (temocapril) and an Ang II type 1 receptor antagonist (CS-866) to cardiomyopathic hamsters.

METHODS AND RESULTS

In human fibroblasts, HGF significantly increased the production of matrix metalloprotease-1 (MMP-1) and urokinase plasminogen activator, whereas HGF also significantly attenuated the reduction of MMP-1 activity induced by Ang II. In contrast, HGF significantly decreased transforming growth factor (TGF)-beta mRNA stimulated by Ang II, whereas HGF also decreased basal TGF-beta protein level without affecting growth. Similarly, in rat cardiac fibroblasts, HGF inhibited the expression and production of TGF-beta, whereas HGF upregulated its specific receptor, c-met. Conversely, in vivo experiments revealed that administration of temocapril and CS-866 to cardiomyopathic hamsters resulted in a significant decrease in fibrotic area and increase in cardiac HGF concentration and mRNA (P<0.01), whereas cardiac concentration and mRNA of HGF were significantly decreased in cardiomyopathic hamsters. In contrast, mRNA expression of collagen III was markedly decreased by treatment with temocapril and CS-866.

CONCLUSIONS

Here, we demonstrated that Ang II blockade prevented myocardial fibrosis in the cardiomyopathic hamster, accompanied by a significant increase in cardiac HGF. Overall, increase in local HGF expression may participate in the prevention of myocardial injury by Ang II blockade through its antifibrotic action.

Subclinical cardiotoxicity following adjuvant dose-escalated FEC, high-dose chemotherapy, or CMF in breast cancer

We compared adjuvant chemotherapy-related myocardial damage by antimyosin scintigraphy in patients who received either nine cycles of FEC (fluorouracil, epirubicin and cyclophosphamide) where the doses of epirubicin and cyclophosphamide were escalated according to the leucocyte nadir (group I, n = 14), three cycles of FEC followed by high-dose chemotherapy with alkylating agents (CTCb) given with the support of peripheral blood stem cell transplantation (group II, n = 14), or six cycles of standard intravenous CMF (cyclophosphamide, methotrexate and fluorouracil; group III, n = 8). The cardiac uptake of In-111-antimyosin-Fab (R11D10) antibody was measured and the heart-to-lung ratio (HLR) calculated 8-36 months after the last dose of chemotherapy. Cardiac antimyosin antibody uptake was considerably higher among patients treated with nine cycles of dose-escalated FEC than among those who were treated with three cycles of FEC and high-dose CTCb (HLR, median 1.98; range 1.36-2.24 vs median 1.51; range 1.20-1.82; P < 0.001), or those treated with CMF (median 1.44; range 1.15-1.68; P < 0.001). The difference between groups II and III was not significant (P > 0.1). A linear association was found between the cumulative dose of epirubicin and the cardiac antimyosin uptake (P < 0.001). We conclude that subclinical cardiac damage caused by three cycles of conventional-dose FEC followed by one cycle of high-dose CTCb chemotherapy is small as compared with the damage caused by dose-escalated FEC.

Anthracycline-induced cardiomyopathy

Anthracycline cardiomyopathy is less frequently encountered nowadays, due to the well-recognised dose limitations and cardiac monitoring protocols used by chemotherapy centres. However, it is a condition that will persist due to the sensitivity of some patients to these drugs and the necessity for large doses to be used for certain individuals. We have demonstrated the benefit of angiotensin-converting enzyme inhibitor therapy and would consider introducing these compounds at the earliest opportunity. The use of probucol and vitamins as antioxidants capable of preventing the onset of cardiomyopathy in humans appears to require further investigation but may significantly reduce the incidence of this condition in the future.