Prophylaxis of 5-fluorouracil-induced coronary vasospasm with calcium channel blockers

Reintroduction of 5-Fluorouracil Post-cardiac Arrest Secondary to Chemotherapy-Induced Cardiotoxicity

5-fluorouracil (5-FU) has been known to have cardiotoxic side effects, including coronary vasospasm, myocardial infarctions, heart failure, arrhythmias, and cardiac arrest. These cases have been reported in patients with either known coronary disease or known risk factors. In cases of acute cardiotoxicity, cessation of fluoropyrimidines is recommended, and reintroduction of the medication is generally avoided. We present a case of a young patient with no known risk factors for coronary disease, who presented with an acute cardiac arrest suspected secondary to vasospasm from the administration of 5-FU for the treatment of rectal cancer and was successfully maintained on treatment with 5-FU post-arrest after transitioning from an infusion to bolus administration.

Myocardial Ischemia Related to Common Cancer Therapy-Prevention Insights

Modern antineoplastic therapy improves survival and quality of life in cancer patients, but its indisputable benefits are accompanied by multiple and major side effects, such as cardiovascular ones. Endothelial dysfunction, arterial spasm, intravascular thrombosis, and accelerated atherosclerosis affect the coronary arteries, leading to acute and chronic coronary syndromes that negatively interfere with the oncologic treatment. The cardiac toxicity of antineoplastic agents may be mitigated by using adequate prophylactic measures. In the absence of dedicated guidelines, our work provides the most comprehensive, systematized, structured, and up-to-date analyses of the available literature focusing on measures aiming to protect the coronary arteries from the toxicity of cancer therapy. Our work facilitates the implementation of these measures in daily practice. The ultimate goal is to offer clinicians the necessary data for a personalized therapeutic approach for cancer patients receiving evidence-based oncology treatments with potential cardiovascular toxicity.

Cardioprotective effects of bosentan in 5-fluorouracil-induced cardiotoxicity

5-fluorouracil (5-FU) is a widely used chemotherapeutic agent but cardiotoxicity challenges its clinical usefulness. Thus, searching for more cardioprotective drugs is highly required to prevent the accompanied cardiac hazards. Up to date, the different mechanisms involved in 5-FU cardiotoxicity are still unclear and there is no evaluation of bosentan's role in controlling these cardiac complications. This forced us to deeply study and evaluate the possible cardiopreserving properties of bosentan and different mechanisms involved in mediating it. 32 Wistar albino rats were included in our experiment and induction of cardiotoxicity was performed via administration of 5-FU (150 mg/kg) on 5th day of the experiment by intraperitoneal (i.p.) injection with or without co-administration of bosentan (50 mg/kg/day) orally for 7days. Our data revealed that 5-FU could induce cardiotoxicity which was detected as significant increases of troponin I, lactate dehydrogenase (LDH), creatine kinase- MB (CK-MB), endothelin receptors, malondialdehyde (MDA), toll like receptor4 (TLR4), myeloid differentiation primary response 88 (MyD88), nuclear factor kappa B (NFκB), and caspase 3 levels. However, there is marked decrease in endothelial nitric oxide synthase (eNOS), reduced glutathione (GSH) and total antioxidant capacity (TAC). In addition, the histopathological examination showed severe toxic features of cardiac injury. Interestingly, co-administration of bosentan could ameliorate 5-FU-induced cardiotoxicity via improving the detected biochemical and histopathological changes besides modulation of TLR4/MyD88/NFκB signaling pathway, eNOS, and endothelin receptors. Bosentan had a significant cardioprotective effect against 5-FU induced cardiac damage. This effect may be attributed to its ability to inhibit endothelin receptors, stimulates eNOS, anti-oxidant, anti-inflammatory, anti-apoptotic properties with modulation of TLR4/MyD88/NFκB signaling pathway.

What the Cardiologist Needs to Consider in the Management of Oncologic Patients with STEMI-Like Syndrome: A Case Report and Literature Review

In pre-hospital care, an accurate and quick diagnosis of ST-segment elevation myocardial infarction (STEMI) is imperative to promptly kick-off the STEMI network with a direct transfer to the cardiac catheterization laboratory (cath lab) in order to reduce myocardial infarction size and mortality. Aa atherosclerotic plaque rupture is the main mechanism responsible for STEMI. However, in a small percentage of patients, emergency coronarography does not reveal any significant coronary stenosis. The fluoropyrimidine agents such as 5-Fluorouracil (5-FU) and capecitabine, widely used to treat gastrointestinal, breast, head and neck cancers, either as a single agent or in combination with other chemotherapies, can cause potentially lethal cardiac side effects. Here, we present the case of a patient with 5-FU cardiotoxicity resulting in an acute coronary syndrome (ACS) with recurrent episodes of chest pain and ST-segment elevation.. Our case report highlights the importance of widening the knowledge among cardiologists of the side effects of chemotherapeutic drugs, especially considering the rising number of cancer patients around the world and that fluoropyrimidines are the main treatment for many types of cancer, both in adjuvant and advanced settings.

Alternative Treatment Options in Patients with Colorectal Cancer Who Encounter Fluoropyrimidine-Induced Cardiotoxicity

5-Fluorouracil (5-FU) remains to be the backbone of chemotherapy regimens approved for treatment of colorectal cancer and other gastrointestinal cancers and breast cancer. The incidence of cardiotoxicity associated with 5-FU ranges from 1.5-18%. Previous studies also concluded that rechallenging a patient with previous 5-FU cardiotoxicity with either lower dose or another mode of administration could result in repeat of cardiac complication in up to 45% of patients. Nearly 13% of patients died upon re-exposure to 5-FU. Clinical manifestations of cardiac complications of fluoropyrimidines including angina, myocardial infarction, arrhythmias, hypotension, Tako-Tsubo syndrome, heart failure, cardiogenic shock, pericarditis, and even sudden death have been reported. Cardiotoxicity is unpredictable and no alternative chemotherapeutics have been defined so far. The author describes here treatment options for patients with metastatic colorectal cancer who have encountered fluoropyrimidine-induced cardiotoxicity, including switching to a different fluoropyrimidine, switching to a different schedule of intravenous 5-FU, or switching to a non-fluoropyrimidine-containing chemotherapy regimen if one exists. Switching to a non-fluoropyrimidine-containing chemotherapy regimen is usually the most feasible choice for patients with metastatic disease as data on adjuvant setting is usually a fluoropyrimidine or its combination with oxaliplatin at present.

5-FU induced cardiotoxicity: case series and review of the literature

Background

5-Fluorouracil (5-FU) is an antimetabolite chemotherapy used for a variety of solid tumors. It has the potential to cause a wide spectrum of cardiotoxicity, ranging from asymptomatic electrocardiographic changes to cardiomyopathy and subsequent cardiac failure. Main body of the abstract: We present two descriptive cases of new-onset severe cardiomyopathy induced by 5-FU followed by a review of the literature.

Conclusion

Our case series emphasizes the importance of early recognition of this rare complication and prompt cessation of 5-FU, as cardiac dysfunction in this context is potentially reversible.

Coronary Artery Vasospasm Induced by 5-fluorouracil: Proposed Mechanisms, Existing Management Options and Future Directions

Cardiovascular disease and cancer are leading contributors to the global disease burden. As a result of cancer therapy-related cardiotoxicities, cardiovascular disease results in significant morbidity and mortality in cancer survivors and patients with active cancer. There is an unmet need for management of cardio-oncology conditions, which is predicted to reach epidemic proportions, and better understanding of their pathophysiology and treatment is urgently required. The proposed mechanisms underlying cardiotoxicity induced by 5-fluorouracil (5-FU) are vascular endothelial damage followed by thrombus formation, ischaemia secondary to coronary artery vasospasm, direct toxicity on myocardium and thrombogenicity. In patients with angina and electrocardiographic evidence of myocardial ischaemia due to chemotherapy-related coronary artery vasospasm, termination of chemotherapy and administration of calcium channel blockers or nitrates can improve ischaemic symptoms. However, coronary artery vasospasm can reoccur with 5-FU re-administration with limited effectiveness of vasodilator prophylaxis observed. While pre-existing coronary artery disease may increase the ischaemic potential of 5-FU, cardiovascular risk factors do not appear to completely predict the development of cardiac complications. Pharmacogenomic studies and genetic profiling may help predict the occurrence and streamline the treatment of 5-FU-induced coronary artery vasospasm. Echocardiographic measures such as the Tei index may help detect subclinical 5-FU cardiotoxicity. Further research is required to explore the cardioprotective effect of agents such as coenzyme complex, GLP-1 analogues and degradation inhibitors on 5-FU-induced coronary artery vasospasm.

Arterial thrombosis and cancer

Cancer-associated arterial thrombotic events (ATEs) are increasingly recognized in specific malignancies and in association with the expanding armamentarium of novel chemotherapeutic agents. The improved cancer survival led to cardiovascular complications becoming clinically relevant many years after cancer diagnosis. The pathobiology of ATEs in cancer is complex and the individual patient risk for an ATE entails a multifactorial interaction between the traditional cardiovascular risk factors and comorbidities, the specific malignancy and selected therapy. Treatment with several specific chemotherapeutic agents, immunomodulatory drugs, vascular endothelial growth factor pathway inhibitors, tyrosine kinase inhibitors, and radiotherapy, impart increased risk for ATEs that result from specific therapy-related mechanisms, often involving endothelial injury. Cancer cell-specific prothrombotic properties are important players in the pathogenesis of cancer-associated hypercoagulability. There are distinct biological and molecular processes preferentially activated in specific cancer cells which can trigger ATEs, including platelet activation, increased expression of procoagulants and suppression of fibrinolytic activity. ATEs portend adverse prognosis in cancer patients. Prevention and treatment of cancer-associated ATEs may be improved by greater awareness and careful monitoring for vascular toxicity, aggressive effort to optimize conventional cardiovascular risk factors, and use of antiplatelet and antithrombotic agents in selected patients. These issues are targets for future studies aimed to reduce ATEs in patients with cancer.

5-fluorouracil and cardiotoxicity: a review

Fluoropyrimidines such as 5-fluorouracil (5-FU) form the foundation of a wide variety of chemotherapy regimens. 5-FU is in fact the third most commonly used chemotherapeutic agent in the treatment of solid malignancies across the world. As with all chemotherapy, balancing the potential benefits of therapy against the risks of drug-related toxicity is crucial when clinicians and patients make shared decisions about treatment. 5-FU is the second most common chemotherapeutic drug associated with cardiotoxicity after anthracyclines, which can manifest as chest pain, acute coronary syndrome/myocardial infarction or death. Nevertheless a widespread appreciation of 5-FU-related cardiotoxicity and its implications is lacking amongst clinicians. In this review, we outline the incidence, possible risk factors, and likely pathophysiological mechanisms that may account for 5-FU-related cardiotoxicity and also highlight potential management strategies for this poorly understood clinical entity.

Cardiovascular Concerns in BRCA1 and BRCA2 Mutation Carriers

PURPOSE OF REVIEW

BRCA1 and BRCA2 mutation carriers can be at increased cardiovascular risk. The goal of this review is to provide information about factors associated with increased cardiovascular risk, methods to prevent cardiovascular toxicities, and recommended screening guidelines.

RECENT FINDINGS

BRCA1/2 mutation carriers who are diagnosed with cancer are often exposed to chemotherapy, chest radiotherapy, and/or HER2 directed therapies, all of which can be cardiotoxic. In addition, BRCA1/2 carriers often undergo prophylactic salpingoopherectomies, which may also increase cardiovascular risks. Understanding the potential for increased cardiovascular risk in individuals with a BRCA1 or BRCA2 mutation, as well as gold standard practices for prevention, detection, and treatment of cardiac concerns in this population, is important.

Fluoropyrimidine-Induced Cardiotoxicity: Manifestations, Mechanisms, and Management

Fluoropyrimidines-5-fluorouracil (5-FU) and capecitabine-have been implicated as cardiotoxic chemotherapy agents. This rare, albeit potentially serious toxicity has been described in nearly four decades of case reports, case series, and in vitro modeling; however, there is a paucity in clinical trials and prospective analyses focused on cardioprotective strategies and cardiotoxic surveillance of these agents. While much attention has focused on the well-known cardiac toxicity of anthracyclines and monoclonal antibody agents such as trastuzumab, fluoropyrimidines remain one of the most common causes of chemotherapy-associated cardiotoxicity. The introduction of capecitabine, an oral prodrug of 5-FU, has made the treatment of solid tumors more convenient along with a subsequent rise in documented cardiotoxic cases. This review discusses the symptomatology, clinical manifestations, and proposed molecular mechanisms that attempt to describe the heterogeneous spectrum of fluoropyrimidine-induced cardiotoxicity. Four case examples showcasing the varied manifestations of cardiotoxicity are presented. Finally, several proposed management strategies for cardiotoxicity and post-hospital course precautions are discussed.

Capecitabine-induced cardiotoxicity mimicking myocardial infarction

Capecitabine, a fluoropyrimidine derivative, is an orally administered drug that delivers 5-fluorouracil (5-FU) selectively to the tumour. The drug has demonstrated activity in metastatic colorectal cancer. We describe a male patient receiving capecitabine therapy with typical chest pain and electrocardiographic changes consistent with STsegment elevation myocardial infarction. Capecitabine-induced cardiotoxicity may develop in patients who have had a previous episode of 5-FU-induced cardiotoxicity. Capecitabine-induced cardiotoxicity is a rare condition that may lead to diagnostic and therapeutic dilemmas. (Neth Heart J 2009;17:277-80.).

Capecitabine in breast cancer: the issue of cardiotoxicity during fluoropyrimidine treatment

Capecitabine is an orally available fluoropyrimidine carbamate that selectively delivers fluorouracil (5-FU) to tissues expressing high levels of thymidine phosphorylase (TP) such as tumors. The drug has demonstrated efficacy in metastatic breast cancer, colorectal, and pancreatic cancer. Although these are considered safe drugs, a growing body of literature reports adverse cardiac effects. Clinical trials indicate that capecitabine has a cardiac toxicity similar to that of infused fluoropyrimidines such as 5-FU. Here, we review cardiotoxicity in the use of fluoropyrimidines, with particular attention toward capecitabine. We also describe a severe, reversible cardiac event that occurred in a 39-year-old woman, with no cardiac risk factors, treated with capecitabine for advanced breast cancer. This review and our experience confirm that fluoropyrimidine cardiotoxicity is an infrequent but documented side effect. Oncology patients under treatment should be closely observed and monitored for cardiac symptoms with particular attention in case of signs or symptoms of cardiovascular complications. The implementation of cardio-oncology interdisciplinary teams should, in the future, reduce the impact of cancer treatment-associated cardiotoxicity syndromes.

Fluoropyrimidine-associated cardiotoxicity: revisited

BACKGROUND

The syndrome of 5-fluorouracil (5-FU)-associated cardiotoxicity remains poorly defined.

PATIENTS AND METHODS

We performed a literature review (1969 - 2007) and compiled data derived from 377 evaluable cases out of 448 reported cases.

RESULTS

Patient age ranged from 14 to 86 years. Of the patients 65% were 55 years old and the male:female ratio was 1.5:1. The most commonly treated tumors were gastrointestinal (60%), head and neck (22%) and breast (4%). Of the patients 14% had a history of heart disease whereas cardiac risk factors were found in 37%. Mode of administration included: continuous infusion (72%); bolus (22.5%); intermediate infusion (3%); oral (2%); and intraperitoneal (1 patient). The dosages of 5-FU used were < 750 mg/m(2)/day (36%), 751 - 999 (16%), 1,000 (26%), 1,001 - 1,499 (4%) and 1,500 (16%). Of the patients 54% received 5-FU in combination with other chemotherapeutic agents (cisplatin 44%) whereas 51% received 5-FU alone or with leucovorin. Only 4% patients had undergone previous or concomitant radiation therapy to the mediastinum. Of cardiac incidents that happened 69% were seen during or within 72 h of the first cycle of 5-FU. Angina occurred in 45% of patients whereas myocardial infarction was seen in 22%, arrhythmias in 23, acute pulmonary edema in 5, cardiac arrest and pericarditis in 1.4 and heart failure in 2. Electro-cardiographic evidence of ischemia or ST-T changes were recorded in 69% of patients, but abnormal cardiac enzymes were found in only 12%. The cardiac symptoms were reproducible in 47%, including in one patient subsequently treated with 5-FU p.o. Symptoms were also elicited when the same patients were treated with lower doses or different schedules. Of the patients 68% responded to conservative anti-anginal therapy, although prophylactic coronary vasodilators had limited efficacy. Overall, 8% of patients showing cardiotoxicity on 5-FU administration died. Furthermore, 13% reexposed to 5-FU died.

CONCLUSIONS

Our review suggests that 5-FU cardiotoxicity is an infrequent but real phenomenon that is independent of dose and may be related to a continuous infusion schedule. The presence of cardiac risk factors is not predictive. Patients should be observed closely and 5-FU administration discontinued if cardiac symptoms develop. A rechallenge with 5-FU should be reserved only for those patients in whom there is no reasonable alternative therapy and should be performed in the setting of aggressive prophylaxis and close monitoring.

Vascular Toxicity of Antineoplastic Agents

Among the various deleterious effects of cancer chemotherapy, vascular toxicity is the least well recognized. This lack of recognition may be because the vasculotoxic phenomena are not unique to antineoplastic agents, can occur in patients without exposure to these agents, and the fact cancer itself may produce a hypercoagulable state. As a result, many vascular events either go unnoticed, are ignored, and/or are attributed to the underlying malignancy. Many antineoplastic therapies are associated with various vascular phenomena that range from simple phelibitis to lethal microangiopathy. Recognition of these events is important to minimize the morbidity and even prevent unnecessary deaths. Herein we review the vascular syndromes that have been reported in association with antineoplastic agents.

Cardiotoxicity of cancer chemotherapy: implications for children

Many children and adolescents with cancer receive chemotherapeutic agents that are cardiotoxic. Thus, while survival rates in this population have improved for some cancers, many survivors may experience acute or chronic cardiovascular complications that can impair their quality of life years after treatment. In addition, cardiac complications of treatment lead to reductions in dose and duration of chemotherapy regimens, potentially compromising clinical efficacy. Anthracyclines are well known for their cardiotoxicity, and alkylating agents, such as cyclophosphamide, ifosfamide, cisplatin, busulfan, and mitomycin, have also been associated with cardiotoxicity. Other agents with cardiac effects include vinca alkaloids, fluorouracil, cytarabine, amsacrine, and asparaginase and the newer agents, paclitaxel, trastuzumab, etoposide, and teniposide. The heart is relatively vulnerable to oxidative injuries from oxygen radicals generated by chemotherapy. The cardiac effects of these drugs include asymptomatic electrocardiographic abnormalities, blood pressure changes, arrhythmias, myocarditis, pericarditis, cardiac tamponade, acute myocardial infarction, cardiac failure, shock, and long-term cardiomyopathy. These effects may occur during or immediately after treatment or may not be apparent until months or years after treatment. Mild myocardiocyte injury from chemotherapy may be of more concern in children than in adults because of the need for subsequent cardiac growth to match somatic growth and because survival is longer in children. Primary prevention is therefore important. Patients should be educated about the cardiotoxic risks of treatment and the need for long-term cardiac monitoring before chemotherapy is begun. Cardiotoxicity may be prevented by screening for risk factors, monitoring for signs and symptoms during chemotherapy, and continuing follow-up that may include electrocardiographic and echocardiographic studies, angiography, and measurements of biochemical markers of myocardial injury. Secondary prevention should aim to minimize progression of left ventricular dysfunction to overt heart failure. Approaches include altering the dose, schedule, or approach to drug delivery; using analogs or new formulations with fewer or milder cardiotoxic effects; using cardioprotectants and agents that reduce oxidative stress during chemotherapy; correcting for metabolic derangements caused by chemotherapy that can potentiate the cardiotoxic effects of the drug; and cardiac monitoring during and after cancer therapy. Avoiding additional cardiotoxic regimens is also important in managing these patients. Treating the adverse cardiac effects of chemotherapy will usually be dependent on symptoms or will depend on the anticipated cardiovascular effects of each regimen. Treatments include diuresis, afterload reduction, beta-adrenoceptor antagonists, and improving myocardial contractility.

Coronary artery spasm induced by 5-fluorouracil

The frequently used chemotherapeutic drug 5-fluorouracil (5-FU) is known to cause angina pectoris and arrhythmias; myocardial infarction and sudden cardiac death could occur. Potential reasons for these phenomena range from toxic/metabolic disturbances to coronary artery spasms. This report shows angiographically proven spasmophilia of the coronary arteries and contributes to the understanding of angina pectoris occurring during treatment with 5-FU. Thus, verapamil type calcium antagonists as well as nitrates should be administered primarily in patients with coronary artery disease and in all patients who had been symptomatic during 5-FU administration in order to prevent further episodes.

5-Fluorouracil induces arterial vasocontractions

BACKGROUND

From 2% to 10% of cancer patients treated with 5-fluorouracil (5-FU) will develop symptomatic cardiotoxicity. Nevertheless, the underlying pathophysiology is mostly unknown.

PATIENTS AND METHODS

We investigated the influence of intravenous chemotherapy (CTX) on the diameter of the brachial artery using high resolution ultrasound in patients with malignant tumors, mostly gastrointestinal cancer. Cytostatic drugs included 30 cases with 5-FU and 30 cases with non-5-FU CTX (cis/carboplatin, anthracycline and cyclophosphamide). In addition, plasma levels of big endothelin were assessed prior to and after CTX.

RESULTS

Fifteen of 30 patients (50%) showed a contraction of the brachial artery after the end of 5-FU application (median 11%, range 4.3-18.5), whereas no single contraction was noticed in 30 patients following non-5-FU-based CTX. Vessel tonus generally normalized within 30 min after stopping 5-FU. Five patients positive for 5-FU associated vessel contraction were repeatedly exposed to 5-FU. Vessel contractions reoccurred in 86% (18/21) of these administrations. When patients with 5-FU bolus application were pre-treated with glyceroltrinitrate no contraction of the brachial artery was detected in five out of five occasions. There was a trend towards increased big endothelin plasma levels after 5-FU application (median 1.52 versus 1.99 fmol/ml; P = 0.07), whereas big endothelin levels remained unchanged after non-5-FU CTX (1.83 versus 1.83 fmol/ml; P = 0.99).

CONCLUSIONS

Application of 5-FU is commonly accompanied by arterial vessel contractions, which is likely to represent the first step in 5-FU-induced cardiotoxicity. 5-FU-associated vessel contractions were highly reproducible on re-exposure and were in the case of bolus application completely preventable by glyceroltrinitrate.

Prophylactic options in patients with 5-fluorouracil-associated cardiotoxicity

At present, the various mechanisms involved in 5-fluorouracil (5-FU)-correlated cardiotoxicity remain to be elucidated and a universally accepted prophylaxis or treatment for this specific toxicity is not available. Although it may improve time to progression, survival and clinical benefit, a 5-FU-based regimen usually has to be discontinued if a patient experiences cardiotoxicity. Here, we describe our experience with three cases of 5-FU-associated cardiotoxicity. The angina-like pain that appeared approximately 95 h after beginning 5-FU therapy was apparently independent of the drug's administration modality. In the two patients receiving 5-FU 12-h flat continuous infusion from 22.00 to 10.00 h (5-FU 12-h c.i.) in combination with other drugs, the dose of 5-FU was reduced by 10-20% and patients received prophylactic transepidermal nitroglycerin. In the third patient, 5-FU administration modality was changed and prophylactic therapy was not given. By taking these precautions, the patients no longer complained of anginal pain and none of them discontinued chemotherapy.

Capecitabine can induce acute coronary syndrome similar to 5-fluorouracil

Capecitabine is a member of a new class of oral fluoropyrimidines. It is a 5-fluorouracil (5-FU) prodrug, activated by a series of enzymes. Activation has been demonstrated to occur preferentially in tumor tissue, which may explain the favorable balance of efficacy and toxicity of this drug. Cardiotoxicity, a rare but potentially serious adverse effect of 5-FU, has not been reported for capecitabine to date. Here we report a patient who experienced a severe and prolonged acute coronary syndrome during treatment with capecitabine. He had previously developed similar symptoms during treatment with infusional 5-FU. Capecitabine should thus be considered an agent with cardiotoxic potential. This adverse effect should be specifically monitored in all patients treated with capecitabine. Patients with symptoms suggestive of cardiotoxicity during previous treatment with a fluoropyrimidine should not be treated with capecitabine.

Cardiotoxicity of chemotherapeutic agents: incidence, treatment and prevention

Cytostatic antibiotics of the anthracycline class are the best known of the chemotherapeutic agents that cause cardiotoxicity. Alkylating agents such as cyclophosphamide, ifosfamide, cisplatin, carmustine, busulfan, chlormethine and mitomycin have also been associated with cardiotoxicity. Other agents that may induce a cardiac event include paclitaxel, etoposide, teniposide, the vinca alkaloids, fluorouracil, cytarabine, amsacrine, cladribine, asparaginase, tretinoin and pentostatin. Cardiotoxicity is rare with some agents, but may occur in >20% of patients treated with doxorubicin, daunorubicin or fluorouracil. Cardiac events may include mild blood pressure changes, thrombosis, electrocardiographic changes, arrhythmias, myocarditis, pericarditis, myocardial infarction, cardiomyopathy, cardiac failure (left ventricular failure) and congestive heart failure. These may occur during or shortly after treatment, within days or weeks after treatment, or may not be apparent until months, and sometimes years, after completion of chemotherapy. A number of risk factors may predispose a patient to cardiotoxicity. These are: cumulative dose (anthracyclines, mitomycin); total dose administered during a day or a course (cyclophosphamide, ifosfamide, carmustine, fluorouracil, cytarabine); rate of administration (anthracyclines, fluorouracil); schedule of administration (anthracyclines); mediastinal radiation; age; female gender; concurrent administration of cardiotoxic agents; prior anthracycline chemotherapy; history of or pre-existing cardiovascular disorders; and electrolyte imbalances such as hypokalaemia and hypomagnesaemia. The potential for cardiotoxicity should be recognised before therapy is initiated. Patients should be screened for risk factors, and an attempt to modify them should be made. Monitoring for cardiac events and their treatment will usually depend on the signs and symptoms anticipated and exhibited. Patients may be asymptomatic, with the only manifestation being electrocardiographic changes. Continuous cardiac monitoring, baseline and regular electrocardiographic and echocardiographic studies, radionuclide angiography and measurement of serum electrolytes and cardiac enzymes may be considered in patients with risk factors or those with a history of cardiotoxicity. Treatment of most cardiac events induced by chemotherapy is symptomatic. Agents that can be used prophylactically are few, although dexrazoxane, a cardioprotective agent specific for anthracycline chemotherapy, has been approved by the US Food and Drug Administration. Cardiotoxicity can be prevented by screening and modifying risk factors, aggressively monitoring for signs and symptoms as chemotherapy is administered, and continuing follow-up after completion of a course or the entire treatment. Prompt measures such as discontinuation or modification of chemotherapy or use of appropriate drug therapy should be initiated on the basis of changes in monitoring parameters before the patient exhibits signs and symptoms of cardiotoxicity.

Acute myocardial infarction following gemcitabine therapy--a case report

The authors report a case of acute myocardial infarction following gemcitabine infusion and electrocardiographic abnormalities suggestive of ischemia on rechallenge of the drug. The possible underlying mechanisms of ischemia and/or infarction and the strategies for prevention are discussed.

Cardiotoxicity of the antiproliferative compound fluorouracil

The antimetabolite fluorouracil (5-FU) is frequently administered for chemotherapy of various malignant neoplasms. The drug is well known for its adverse effects involving bone marrow, skin, mucous membranes, intestinal tract and central nervous system, whereas its cardiotoxicity is less familiar to clinicians. The pathophysiology of fluorouracil-associated cardiac adverse events is controversial and conclusions are based on clinical studies and case reports more than on solid experimental evidence. While clinical and electrocardiographic features suggest myocardial ischaemia as a main aetiological factor, possibly induced by coronary vasospasm, histomorphological and biochemical studies indicate a more direct drug-mediated cytotoxic action. Estimates of the overall incidence of fluorouracil cardiotoxicity have varied widely from 1.2 to 18% of patients. Patients may present with angina-like chest pain, cardiac arrhythmias or myocardial infarction. There is no unequivocally effective prophylaxis or treatment in this syndrome. Once fluorouracil administration is discontinued symptoms are usually reversible, although fatal events have been described. The overall mortality rate has been estimated to be between 2.2 and 13.3%. There is a high risk of relapse when patients are re-exposed to this drug following previous cardiac incidents. From the present data it is concluded that cardiotoxicity is a relevant but underestimated problem in fluorouracil treatment. Since the mechanisms of fluorouracil-associated cardiotoxicity are not yet fully understood, all patients undergoing this chemotherapy have to be carefully evaluated and monitored for cardiac risk factors and complaints. After cardiotoxic events, fluorouracil should definitely be withdrawn and replaced by an alternative antiproliferative regimen.

Myocardial ischemia induced by topical use of 5-fluorouracil

An 85-year-old woman, with known stable angina pectoris, was prescribed 5-fluorouracil cream to treat a small basal cell carcinoma on the forehead. Half an hour after application the patient developed her typical ischemic pain which persisted for 2 hours. Rechallenge, during hospitalization, resulted in recurrence of symptoms that were effectively controlled with sublingual isosorbide dinitrate. Prophylactic therapy with nitroglycerin patch enabled further use of the 5-fluorouracil cream for the next month.

Changes of blood viscosity in patients treated with 5-fluorouracil--a link to cardiotoxicity?

Cardiotoxicity is a serious but relatively unknown side-effect of treatment with 5-fluorouracil (5-FU). The underlying mechanism of 5-FU cardiotoxicity has not been defined. The aim of the present study was to determine whether hemorheological factors might in part explain 5-FU cardiotoxicity. Changes of blood and plasma viscosity, fibrinogen and hematocrit were studied in 11 patients treated by 5-FU. The study showed a decrease in blood and plasma viscosity during treatment with 5-FU, probably caused by a decrease of plasma fibrinogen. Reversible cardiotoxic effects were demonstrated in four patients.

Clinical cardiotoxicity of 5-fluorouracil

5-Fluorouracil is widely known to be toxic to the hematopoietic and gastrointestinal systems. It also has cardiac toxicity, but this is perceived to be rare. During a 16-month period from January 1990 through April 1991, approximately 910 patients were treated with 5-fluorouracil. Five of these developed life-threatening toxicity consistent with coronary artery spasm for an incidence of .55%. The acute events occurred on the third or fourth day of the 5-day infusion and after the fourth intravenous bolus in the patient on bolus therapy. Each of the patients had ST elevation and ventricular arrhythmias, four had acute myocardial infarction, and two had cardiac arrests. In these cases and those previously reported, cardiac toxicity is consistent with drug- or metabolite-mediated increases in coronary vasomotor tone and spasm, leading to the full spectrum of signs and symptoms of myocardial ischemia in susceptible individuals.

The syndrome of 5-fluorouracil cardiotoxicity. An elusive cardiopathy

BACKGROUND

A case of reversible cardiogenic shock linked to 5-fluorouracil (5-FU) was observed. Recognizing the increasing use of 5-FU, the authors tried to map this syndrome.

METHODS

They reviewed 134 additional case reports, retrieved information from literature searches, focused on clinical features, and discussed possible pathophysiologic findings and prevention of this syndrome.

RESULTS

Although angina and electrocardiographic changes were common and reproducible (approximately 90% each), coronary artery disease was found in a few patients. A total of 33 patients had severe left ventricular dysfunction, 28 without evidence of myocardial infarction. The symptoms were responsive to conservative management (90%).

CONCLUSIONS

Cardiac toxicity is a little known complication of 5-FU therapy, with an unknown but significant incidence. It is highly treatable.

Current research in side effects of high-dose chemotherapy

The toxicities of chemotherapy continue to hamper dose escalation of specific chemotherapeutic agents. The impact of dose intensification upon survival will be assessed as clinical studies continue. Strategies to support chemotherapy dose intensification include BMT, use of CSFs and antiemetic drug combinations. Advances in symptom management will hopefully enhance quality of life for patients, whereas the development of chemoprotectant agents may allow specific organ toxicities to be avoided.

Failure of preventing 5-fluorouracil cardiotoxicity by prophylactic treatment with verapamil

The most common cardiotoxic effects of 5-fluorouracil (5-FU) are chest pain and ischemic ECG abnormalities. Coronary vasospasm may be the underlying mechanism. If so, prophylactic treatment with calcium channel blockers might have a beneficial effect. In the present study, prophylaxis with verapamil (120 mg three times daily) was given to 58 patients with esophageal or advanced head and neck carcinoma during induction chemotherapy with cisplatin and continuous infusion with 5-FU. Signs of ischemia appeared in 12% of the patients as compared to 13% in a previously studied compatible group of patients not receiving prophylaxis. The study does not support the hypothesis that prophylactic treatment with verapamil reduces the incidence of ischemia in patients undergoing 5-FU treatment. Verapamil might, however, modify the adverse cardiac effects of 5-FU by preventing supraventricular tachyarrhythmia.