5-Fluorouracil cardiotoxicity: left ventricular dysfunction and effect of coronary vasodilators

Downregulating miRNA-199a-5p exacerbates fluorouracil-induced cardiotoxicity by activating the ATF6 signaling pathway

BACKGROUND

Fluorouracil (5-FU) might produce serious cardiac toxic reactions. miRNA-199a-5p is a miRNA primarily expressed in myocardial cells and has a protective effect on vascular endothelium. Under hypoxia stress, the expression level of miRNA-199a-5p was significantly downregulated and is closely related to cardiovascular events such as coronary heart disease, heart failure, and hypertension. We explored whether 5-FU activates the endoplasmic reticulum stress ATF6 pathway by regulating the expression of miRNA-199a-5p in cardiac toxicity.

METHODS

This project established a model of primary cardiomyocytes derived from neonatal rats and treated them with 5-FU in vitro. The expression of miRNA-199a-5p and its regulation were explored in vitro and in vivo.

RESULTS

5-FU decreases the expression of miRNA-199a-5p in cardiomyocytes, activates the endoplasmic reticulum stress ATF6 pathway, and increases the expression of GRP78 and ATF6, affecting the function of cardiomyocytes, and induces cardiac toxicity. The rescue assay further confirmed that miRNA-199a-5p supplementation can reduce the cardiotoxicity caused by 5-FU, and its protective effect on cardiomyocytes depends on the downregulation of the endoplasmic reticulum ATF6 signaling pathway.

CONCLUSIONS

5-FU can down-regulate expression of miRNA-199a-5p, then activate the endoplasmic reticulum stress ATF6 pathway, increase the expression of GRP78 and ATF6, affect the function of cardiomyocytes, and induce cardiac toxicity.

A new perspective in the prevention and treatment of antitumor therapy-related cardiotoxicity: Intestinal microecology

The continuous development of antitumor therapy has significantly reduced the mortality of patients with malignancies. However, the antitumor-related cardiotoxicity has become the leading cause of long-term mortality in patients with malignancies. Besides, the pathogenesis of antitumor-related cardiotoxicity is still unclear, and practical means of prevention and treatment are lacking in clinical practice. Therefore, the major challenge is how to combat the cardiotoxicity of antitumor therapy effectively. More and more studies have shown that antitumor therapy kills tumor cells while causing damage to sensitive tissues such as the intestinal mucosa, leading to the increased permeability of the intestine and the dysbiosis of intestinal microecology. In addition, the dysbiosis of intestinal microecology contributes to the development and progression of cardiovascular diseases through multiple pathways. Thus, the dysbiosis of intestinal microecology may be a potential mechanism and target for antitumor-related cardiotoxicity. We summarized the characteristics of intestinal microecology disorders induced by antitumor therapy and the association between intestinal microecological dysbiosis and CVD. And on this basis, we hypothesized the potential mechanisms of intestinal microecology mediating the occurrence of antitumor-related cardiotoxicity. Then we reviewed the previous studies targeting intestinal microecology against antitumor-associated cardiotoxicity, aiming to provide a reference for future studies on the occurrence and prevention of antitumor-related cardiotoxicity by intestinal microecology.

Managing life-threatening 5-fluorouracil cardiotoxicity

5-Fluorouracil (5-FU), a known cardiotoxin, is the backbone for the treatment of colorectal cancer. It is associated with arrhythmias, myocardial infarction and sudden cardiac death. Most commonly, it is associated with coronary vasospasm secondary to direct toxic effects on vascular endothelium.A woman with metastatic colon cancer, originally treated with a 5-FU infusion as part of the FOLFIRI (Folinic acid, 5-Fluorouracil, Irinotecan) regimen, was unable to tolerate the chemotherapy due to chest pain. She was transitioned from infusional 5-FU to inferior 1-hour bolus 5-FU, in an attempt to minimise cardiotoxicity, but had disease progression. A multidisciplinary decision was made to again trial 5-FU infusion and pretreat with diltiazem. She tolerated chemotherapy without adverse events. A multidisciplinary discussion is recommended for co-management of reversible 5-FU-associated cardiotoxicity. After coronary artery disease (CAD) risk stratification and treatment, empiric treatment with calcium channel blockers and/or nitrates may allow patients with suspected coronary vasospasm, from 5-FU, to continue this vital chemotherapy.

The efficacy and safety of cardio-protective therapy in patients with 5-FU (Fluorouracil)-associated coronary vasospasm

Background

Coronary vasospasm is a known side effect of 5-FU (fluorouracil) therapy. Beyond switching to non-5FU-based chemotherapy, there are no established treatments for 5-FU associated coronary vasospam. Our objective was to assess the safety and efficacy of re-challenge with 5-FU after pre-treatment with calcium channel blockers (CCBs) and long-acting nitrates among patients 5-FU associated coronary vasospasm.

Methods

We conducted a retrospective study of patients with 5-FU coronary vasospasm at a single academic center. By protocol, those referred to cardio-oncology received pre-treatment with either combination [nitrates and CCBs] or single-agent therapy [nitrates or CCBs]) prior to re-challenge with 5-FU. Our primary outcome was overall survival. Other important outcomes included progression-free survival and safety.

Results

Among 6,606 patients who received 5-FU from January 2001 to Dec 2020, 115 (1.74%) developed coronary vasospasm. Of these 115 patients, 81 patients continued 5-FU therapy, while 34 stopped. Of the 81 who continued, 78 were referred to cardio-oncology and prescribed CCBs and/or nitrates prior to subsequent 5-FU, while the remaining 3 continued 5-FU without cardiac pre-treatment. Of the 78, 56.4% (44/78) received both nitrates and CCBs, 19.2% (15/78) received CCBs alone, and 24.4% (19/78) received nitrates alone. When compared to patients who stopped 5-FU, those who continued 5-FU after pre-treatment (single or combination therapy) had a decreased risk of death (HR 0.42, P = 0.005 [95% CI 0.23–0.77]) and a trend towards decreased cancer progression (HR 0.60, P = 0.08 [95% CI 0.34–1.06]). No patient in the pre-treatment group had a myocardial infarct after re-challenge; however, chest pain (without myocardial infarction) recurred in 19.2% (15/78) among those who received cardiac pre-treatment vs. 66.7% (2/3) among those who did not (P = 0.048). There was no difference in efficacy or the recurrence of vasospasm among patients who received pre-treatment with a single agent (nitrates or CCBs) or combination therapy (14.7% (5/34) vs. 25.0% (11/44), P = 0.26).

Conclusion

Re-challenge after pre-treatment with CCBs and nitrates guided by a cardio-oncology service was safe and allowed continued 5-FU therapy.

The Role of Vasospasm and Microcirculatory Dysfunction in Fluoropyrimidine-Induced Ischemic Heart Disease

Cardiovascular diseases and cancer are the leading cause of morbidity and mortality globally. Cardiotoxicity from chemotherapeutic agents results in substantial morbidity and mortality in cancer survivors and patients with active cancer. Cardiotoxicity induced by 5-fluorouracil (5-FU) has been well established, yet its incidence, mechanisms, and manifestation remain poorly defined. Ischemia secondary to coronary artery vasospasm is thought to be the most frequent cardiotoxic effect of 5-FU. The available evidence of 5-FU-induced epicardial coronary artery spasm and coronary microvascular dysfunction suggests that endothelial dysfunction or primary vascular smooth muscle dysfunction (an endothelial-independent mechanism) are the possible contributing factors to this form of cardiotoxicity. In patients with 5-FU-related coronary artery vasospasm, termination of chemotherapy and administration of nitrates or calcium channel blockers may improve ischemic symptoms. However, there are variable results after administration of nitrates or calcium channel blockers in patients treated with 5-FU presumed to have myocardial ischemia, suggesting mechanisms other than impaired vasodilatory response. Clinicians should investigate whether chest pain and ECG changes can reasonably be attributed to 5-FU-induced cardiotoxicity. More prospective data and clinical randomized trials are required to understand and mitigate potentially adverse outcomes from 5-FU-induced cardiotoxicity.

5-Fluorouracil, capecitabine and vasospasm: a scoping review of pathogenesis, management options and future research considerations

BACKGROUND

5-Fluorouracil (5-FU) is a widely used chemotherapeutic agent that can cause cardiotoxicity manifesting, among others, as chest pain. Capecitabine is an oral prodrug of 5-FU, with reported preferential activation in malignant cells that may also cause cardiotoxic reactions. Standard treatment of 5-FU and capecitabine induced chest pain with vasodilators is mostly effective, but there are several cases of patients unresponsive to these agents.

METHODS

We performed a PubMed search on 31st May 2020. We used a three keyword search strategy using Boolean search operators. More specifically, we included fluorouracil or 5-FU or capecitabine and chest pain or angina and mechanism or treatment or management. We included primary reports of clinical and non-clinical data, as well as systematic reviews. Narrative reviews, expert opinions, letters to the editor and other forms of non-primary literature were excluded.

RESULTS

Our search yielded a total of 1595 reports. Of these, 1460 were narrative reviews or irrelevant to the topic and were excluded. A total of 135 reports were used for our review. We used 81 reports for data extraction, which included 13 clinical trials, 4 retrospective reports, 61 case reports, and 3 systematic reviews.

CONCLUSION

We report the incidence and predisposing factors, the value of available diagnostic procedures, and standard medical and invasive treatments. We also speculate on the potential benefit of arginine as a promising option both in prevention as well as treatment of 5-FU-induced chest pain. Finally, gaps of evidence are identified and proposals are made in terms of future research.

Delayed Coronary Vasospasm in a Patient with Metastatic Gastric Cancer Receiving FOLFOX Therapy

A 40-year-old man with stage IV gastric adenocarcinoma was found to have coronary artery vasospasm in the setting of recent 5-fluorouracil administration.

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.

Cardiotoxicities of 5-Fluorouracil and Other Fluoropyrimidines

OPINION STATEMENT

Fluoropyrimidine (FP) is used to treat a wide range of cancers; however, it is associated with drug-induced vascular toxicity, as well as angina pectoris and coronary spasm. FP has been administered for many years, although the incidence, mechanisms, and appropriate methods for managing its associated cardiovascular toxicities have not been clarified, and the management of these complications has not been standardized. This lack of evidence is not limited to FP. Many trials of anticancer agents have been conducted, excluding patients with heart diseases. Hence, there is a paucity of epidemiological data on cardiovascular adverse events caused by anticancer agents. There have been remarkable improvements in cancer treatment in recent years, with consequent improvements in prognosis. In this context, new cardiovascular toxicities related to new drugs have emerged. We are now compelled to respond to cardiovascular adverse events despite the lack of evidence regarding optimal management. The result has been establishment and rapid maturation of the new academic field of cardio-oncology. Despite the relative lack of evidence, we must review small pieces of evidence that have accumulated to date and make the utmost efforts to provide patients with effective evidence-based medical care. Simultaneously, we urgently need randomized clinical trials to build strong evidence.

Acute reversible left ventricular systolic dysfunction associated with 5-fluorouracil therapy: a rare and increasingly recognised cardiotoxicity of a commonly used drug

5-Fluorouracil (5-FU) is the third most common chemotherapeutic agent for treating solid cancers and the second most common to cause cardiotoxicity. We present a rare case of acute reversible severe left ventricular systolic dysfunction associated with 5-FU. A 54-year-old woman with a history of stage IV gastric cancer presented with features of transient ischaemic attack after receiving the first dose of FLOT (5-FU, leucovorin, oxaliplatin and docetaxel). During the diagnostic workup, it was found that her ejection fraction was severely reduced to 15% with features of global hypokinesis, which later improved back to 65% within 13 days. These cases challenge our current understanding of the underlying mechanisms of this cardiotoxicity. Additionally, even though the patient did not experience any cardiac symptoms, it is important to monitor these patients closely as they are at high risk for fatal complications like arrhythmia and thrombus formation.

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.

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.

Ischemic Heart Disease: Special Considerations in Cardio-Oncology

OPINION STATEMENT

The interplay and balance between the competing morbidity and mortality of cardiovascular diseases and cancer have a significant impact on both short- and long-term health outcomes of patients who survived cancer or are being treated for cancer. Ischemic heart disease in patients with cancer or caused by cancer therapy is a clinical problem of emerging importance. Prompt recognition and optimum management of ischemic heart disease mean that patients with cancer can successfully receive therapies to treat their malignancy and reduce morbidity and mortality due to cardiovascular disease. In this sense, the presence of cancer and cancer-related comorbidities (e.g., thrombocytopenia, propensity to bleed, thrombotic status) substantially complicates the management of cardiovascular diseases in cancer patients. In this review, we will summarize the current state of knowledge on the management strategies for ischemic disease in patients with cancer, focusing on the challenges encountered when addressing these complexities.

Gemcitabine and Acute Myocardial Infarction

The objective of this paper is to report a case of acute, non-q-wave myocardial infarction, presumably secondary to gemcitabine chemotherapy for nonsmall cell lung cancer. A 43-year-old woman with postpartum cardiomyopathy and ischemic heart disease was treated with gemcitabine for metastatic nonsmall cell lung cancer. Three days after her 5th treatment with gemcitabine, she developed chest pain and was diagnosed as having acute, non-q-wave myocardial infarction. She made an uneventful recovery. An objective causality assessment revealed that the adverse event was possible. Gemcitabine has been previously reported to be causative of acute myocardial infarction. Ischemic complications of chemotherapeutic agents are discussed. A review of literature on this subject is presented. Gemcitabine should be administered with caution in patients with underlying cardiac disease.

5-Fluorouracil-induced acute reversible heart failure not explained by coronary spasms, myocarditis or takotsubo: lessons from MRI

A 69-year-old woman presented with arterial hypotension, pulmonary oedema and a severely depressed left ventricular ejection fraction (LVEF) of 25% only 3 days after having received her first treatment for colorectal cancer with 5-fluorouracil (5-FU)-based therapy. The ECG demonstrated widespread ST-segment depression and echocardiography showed uniform hypokinesia of all left ventricular (LV) myocardial segments without signs of regional LV ballooning. Coronary angiography was normal and the patient gained full recovery after receiving treatment with heart failure medication. Interestingly, cardiac MRI scan 9 days later showed a normal LVEF with signs of neither myocardial oedema nor necrosis. Despite the high therapeutic efficacy of 5-FU in treatment of colorectal cancer, it is associated with undesired cardiac toxicities including coronary spasms, toxic inflammation and takotsubo cardiomyopathy. However, our patient did not fulfil the diagnostic criteria for the aforementioned complications. Based on this case report, we discuss alternative mechanisms including myocardial adenosine triphosphate depletion suggested from animal experiments.

Usefulness of Heart-Type Fatty Acid-Binding Protein and Myocardial Performance Index for Early Detection of 5-Fluorouracil Cardiotoxicity

In the present study, we aimed to evaluate temporal changes in heart-type fatty acid-binding protein (h-FABP) and myocardial performance index (Tei index) following administration of 5-fluorouracil (5-FU), a chemotherapeutic agent associated with myocardial ischemia induced by coronary vasospasm. Thirty-two patients with cancer receiving their first 5-FU-based chemotherapy were included in the study. Prior to chemotherapy and 24 hours after the initiation of chemotherapy, all patients underwent a comprehensive echocardiographic examination. Blood samples were taken for h-FABP and troponin I (TnI) measurements at different time points during the first 24 hours of 5-FU administration. Postinfusion echocardiography revealed worsening in Tei index (0.37 ± 0.08 vs 0.43 ± 0.07, P < .001). Clinically overt cardiotoxicity was evident in 4 (12.5%) of our patient population. Heart-type fatty acid binding protein and TnI levels were within normal ranges at all time points. Our results suggest that ischemia coronary vasospasm due to 5-FU cardiotoxicity should be reviewed. Furthermore, Tei index might be a sensitive indicator of occult 5-FU cardiotoxicity.

Capecitabine-induced cardiotoxicity: more evidence or clinical approaches to protect the patients' heart?

Fluoropyrimidines, such as capecitabine and 5-fluorouracil, may cause cardiac toxicity. In recent years, the incidence of this side effect has increased and it is expected to further rise due to the population aging and the disproportionate incidence of breast and gastrointestinal cancers in older individuals. The spectrum of cardiac manifestations includes different signs and symptoms and the diagnosis may be difficult. Here, we report the case of a 43-year-old woman with advanced breast cancer who was rechallenged with a capecitabine-based regimen after experiencing a cardiac adverse event during the first fluoropyrimidine exposure. This real-practice case serves as a springboard for discussion about the current evidence on differential diagnosis of capecitabine-related cardiac toxicity, its risk factors, and the underpinning mechanisms of early onset. Moreover, we discussed whether a rechallenge with fluoropyrimidines could be safe in patients who had experienced a previous cardiac adverse event.

A mechanistic study on the cardiotoxicity of 5-fluorouracil in vitro and clinical and occupational perspectives

Fluoropyrimidines are key agents for the treatment of gastrointestinal tract adenocarcinomas. The possible cardiotoxic effects in patients and occupationally exposed workers are multifactorial and remain a puzzle to solve for investigators. In the present study, we study what cell death pathways and what doses can determine direct cardiotoxic effects of 5-fluorouracil (5-FU) and doxorubicin (DOXO) on rat cardiocytes (H9c2) and a human colon adenocarcinoma (HT-29) cell line, already reported to be sensitive to 5-FU. We have found that 5-FU induced 50% growth inhibition (IC:50) at 72 h with concentrations of 400 μM and 4 μM on H9c2 and HT-29, respectively. Moreover, we have found that the addition of Levofolinic Acid (LF) to 5-FU potentiated the growth inhibition induced by 5-FU. The growth inhibition induced by 5-FU alone or in combination with LF in cardiocytes was paralleled by an increase of thiobarbituric acid-reactive species (Tbars) and end products of nitric oxide (NO) suggesting the increase of the oxidative stress status in cardiocytes. Interestingly, these effects were strongly potentiated by the addition of LF, a biochemical modulator of 5-FU activity. Our data suggest that agents such as 5-FU different from anthracyclines, conventionally related to the induction of cardiotoxic effects, can also induce cardiocyte damage paralleled by oxidative stress. The strategies based upon the use of scavengers could be used in order to prevent this effect.

Cardiotoxicity and oncological treatments

BACKGROUND

Cardiotoxic and other side effects limit the usefulness of treatments for cancer.

METHOD

This article is based on pertinent articles that were retrieved by a selective search in PubMed and other databases, and on the guidelines of the European Society of Cardiology, the Association of Scientific Medical Societies in Germany, and the European Society of Medical Oncology.

RESULTS

Prospective studies have shown that some treatments for cancer are cardiotoxic. The heart damage that they cause can manifest itself as arrhythmia, arterial hypertension, thromboembolism, angina pectoris, myocardial infarction, or heart failure. It has been observed that potentially lethal complications can arise as late as 40 years after treatment of the original cancer. The anthracycline drug doxorubicin, given in a dose of 500 mg/m2 of body surface area, has been found to cause cardiac complications in 4-36% of the patients treated with it. Trastuzumab and epirubicin cause dose-limiting cardiac events in 1.7-5% of patients, depending on the dosage. Paclitaxel causes bradycardia, intracardiac conduction block, or arrhythmia in 0.5% of patients. 18% of patients treated with sunitimib or sorafenib have clinical manifestations relating to the heart (angina pectoris, dyspnea). 5-fluorouracil can cause angina pectoris at the beginning of treatment and rarely causes myocardial infarction. Cardiac radiation therapy, a form of treatment practiced in earlier decades, can cause cardiac complications 20 years after the event. The opportunity to prevent cardiac complications of anthracycline drugs with dexrazoxane is decidedly limited, but initial studies have shown that treatment with beta-blockers and ACE inhibitors lessens the likelihood of cardiotoxic side effects. When cardiac complications arise, the generally applicable rules for the treatment of each type of cardiac problem should be followed. The oncological treatment protocol should be adjusted or switched to one that is less damaging to the heart.

CONCLUSION

Treating physicians need to be thoroughly acquainted with the cardiotoxic effects of anti-cancer drugs so that they can diagnose them early on and avoid jeopardizing the overall success of treatment.

5-FU-induced cardiac toxicity--an underestimated problem in radiooncology?

BACKGROUND

5-Fluorouracil (5-FU) is an antimetabolite, which is frequently used as chemotherapeutic agent for combined chemoradiotherapy. The purpose of this study was to present the clinical course of three patients who developed severe cardiac toxicity by 5-FU and to give a review of the literature on the cardiotoxic potential of 5-FU.

RESULTS

Cardiotoxicity is a rare, but relevant side effect of fluoropyrimidines. It comprehends a wide spectrum of side effects, from electrocardiogram changes (69% of cardiac events) to myocardial infarction (22%) and cardiogenic shock (1%).In this case series three patients with cardiotoxic events during chemoradiotherapy including 5-FU, the reaction's characteristics and their influence on further therapy are described. Two of the patients could not be treated with 5-FU any more because they had developed a myocardial ischemia, which was most likely caused by fluorouracil. Another patient, who complained about typical angina pectoris during 5-FU-infusion and had a new left anterior hemiblock, was reexposed with prophylactic administration of nitrendipine.

CONCLUSION

Cardiotoxicity caused by 5-FU is an underestimated problem in radiooncology. Especially patients without history of cardiac disease are often treated as out-patients and therefore without cardiac monitoring. Consequently asymptomatic and symptomatic cardiac events may be overlooked. The benefit of prophylactic agents remains unclear, so close cardiac monitoring is the most established method to prevent manifest cardiotoxic events.

Alternative treatment options in colorectal cancer patients with 5-fluorouracil- or capecitabine-induced cardiotoxicity

Most chemotherapy regimens in colorectal cancer treatment are 5-fluorouracil (5-FU)/leucovorin or capecitabine-based. Cardiotoxicity is a less common but potentially lethal complication of 5-FU or capecitabine treatment, and some physicians might be unfamiliar with treatment alternatives. Rechallenging should be avoided because it carries a high risk of recurrence of the cardiac symptoms and prophylactic treatment is not always protective. Possible alternative treatment options to be considered are to replace the oral capecitabine or intravenous 5-FU by a 5-FU bolus regimen, by uracil-tegafur or tegafur/gimeracil/oteracil, both oral fluoropyrimidines combining a 5-FU prodrug with a dihydropyrimidine dehydrogenase (DPD) inhibitor, or by raltitrexed, a thymidilate synthase inhibitor whose metabolism is independent of DPD. Patients with advanced colorectal cancer and fluoropyrimidine-induced cardiotoxicity can be treated with other non-fluoropyrimidine related chemotherapy, either as a single agent, combined, or in combination with biological agents. In this report we discuss the different alternative treatment options.

A case of severe coronary spasm associated with 5-fluorouracil chemotherapy

Cardiotoxicity associated with 5-fluorouracil (FU) is an uncommon, but potentially lethal, condition. The case of an 83-year-old man with colon cancer who developed chest pain during 5-FU infusion is presented. The electrocardiogram (ECG) showed pronounced ST elevation in the lateral leads, and the chest pain was resolved after infusion of nitroglycerin. A coronary angiogram (CAG) revealed that the patient had significant atherosclerosis in the proximal left circumflex artery. Coronary artery spasm with fixed stenosis was considered, and a drug-eluting stent was implanted. After 8 hours, the patient complained of recurring chest pain, paralleled by ST elevation on the ECG. The chest pain subsided after administration of intravenous nitroglycerin followed by sublingual nifedipine. Repeated CAG showed patency of the previous stent. This case supports the vasospastic hypothesis of 5-FU cardiac toxicity, indicating that a calcium channel blocker may be effective in the prevention or treatment of 5-FU cardiotoxicity.

Capecitabine-induced cardiotoxicity: case report and review of the literature

Capecitabine, an oral prodrug of 5-fluorouracil (5fu), has been integrated into the management of multiple cancer types because of convenience of administration and efficacy comparable with 5fu. Cardiotoxicity induced by 5fu—in particular angina—has been well described in the literature, but reports of adverse cardiac events with capecitabine are also emerging. The mechanism underlying 5fu cardiotoxicity has long been thought to result from coronary vasospasm, but animal-model studies and patient echocardiographic findings both suggest a cardiomyopathic picture. Although 5fu cardiotoxicity is often reversible and can be managed supportively, presentations that are more severe—including arrhythmias, acute ischemic events, and cardiogenic shock—have been documented. In this report, we describe the case of a patient who ultimately required a pacemaker after developing symptomatic bradycardia and sinus arrest while receiving capecitabine for colon cancer.

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.

Severe ventricular dysrhythmias and silent ischemia during infusion of the antimetabolite 5-fluorouracil and cis-platin

The antimetabolite 5-fluorouracil is frequently used in the therapy of various malignancies. Cardiotoxicity has frequently been described during treatment, but there is no common agreement on the need to perform cardiovascular monitoring of patients during 5-fluorouracil administration. We report the case of a young patient with an head-neck cancer on whom a continuous electrocardiogram recording was performed, documenting serious ventricular dysrhythmias in the presence of myocardial ischemia during 5-fluorouracil and cis-platin infusion.

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 therapy

Because cancer is a leading cause of mortality in the United States, the number of therapeutic modalities available for the treatment of neoplastic processes has increased. This has resulted in a large number of patients being exposed to a wide variety of cancer therapy. Historically, it has been well recognized that antineoplastic agents may have adverse effects on multiple organs and normal tissues. The most commonly associated toxicities occur in tissues composed of rapidly dividing cells and may spontaneously reverse with minimal long-term toxicity. However, the myocardium consists of cells that have limited regenerative capability, which may render the heart susceptible to permanent or transient adverse effects from chemotherapeutic agents. Such toxicity encompasses a heterogeneous group of disorders, ranging from relatively benign arrhythmias to potentially lethal conditions such as myocardial ischemia/infarction and cardiomyopathy. In some instances, the pathogenesis of these toxic effects has been elucidated, whereas in others the precise etiology remains unknown. We review herein the various syndromes of cardiac toxicity that are reported to be associated with antineoplastic agents and discuss their putative mechanisms and treatment.

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.

Ultrasound Tissue Characterization by Integrated Backscatter for Analyzing Fluorouracil Induced Myocardial Damage

BACKGROUND

5-Fluorouracil (5-FU) cardiotoxicity is a well-known clinical phenomenon whose pathophysiology remains controversial. Cyclic variation of integrated backscatter (CVIBS) assesses acoustic properties of myocardium that may reflect both contractility and structural changes. The aim of this study was to evaluate CVIBS alterations in cancer patients under high-dose leucovorin and infusional 5-FU (HDLV5FU) chemotherapy.

METHOD

We prospectively evaluated 37 cancer patients under HDLV5FU treatment. Transthoracic echocardiography and CVIBS were performed at the 0th, 48th hours, and on day 15 of the first cycle. The parasternal long-axis view was preferred to obtain the image of integrated backscatter and mainly two regions of interest--interventricular septum (IVS) and posterior wall (PW)--were used.

RESULTS

Clinical cardiotoxicity was observed in two patients. No significant differences were detected in pre- and posttreatment conventional echocardiography evaluations. However, both the IVS (9.3 +/- 1.0 to 8.1 +/- 1.2 dB, P < 0.001) and PW (9.1 +/- 0.7 to 7.8 +/- 0.9 dB, P < 0.001) CVIBS values significantly decreased in all patients. All values were returned to pretreatment levels (9.2 +/- 0.9 dB in the CVIBS-IVS and 8.9 +/- 0.6 dB in CVIBS-PW, respectively) on day 15 after the treatments.

CONCLUSION

This study suggests that HDLV5FU may cause acute transient alterations in CVIBS values in the absence of clinical symptoms and signs of cardiotoxicity. The clinical value of CVIBS should be further studied in patients receiving 5-FU-based therapy.

Influence of high-dose leucovorin and 5-fluorouracil chemotherapy regimen on P wave duration and dispersion

BACKGROUND

Although 5-fluorouracil (5-FU)-related cardiotoxicity is well known, atrial arrhythmia, as a potentially serious complication has not been studied in detail. The aim of this study was to determine the P max and Pd in the electrocardiograms (ECG) of patients receiving 5-FU treatment.

METHODS

Twenty-five patients (mean age: 62 years) receiving a 5-FU bolus plus continuous infusion with calcium leucovorin over 48 h and with normal pre-treatment cardiac physical examinations, ECG and echocardiography were enrolled. P maximum (P max), P minimum (P min) and P dispersion (Pd) (maximum minus minimum P wave duration) were measured from the 12-lead ECG at the 0th and 48th hour of the first chemotherapy cycle. Echocardiography was also obtained in all patients at the same times.

RESULTS

Clinical cardiotoxicity was observed in two patients. P max and Pd were both significantly longer after 5-FU treatment at the 48th hour (P < 0.001). P min did not change (P > 0.05).

CONCLUSION

Treatment with 5-FU based regimens may increase Pd and prolong the P max in cancer patients. These alterations may be predictive of patients at risk of atrial arrhythmias during 5-FU treatment.

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.

Chemotherapy-induced cardiotoxicity: current practice and prospects of prophylaxis

Cardiotoxicity is a potential side effect of few chemotherapeutic agents. The anthracycline class of cytotoxic antibiotics are the most famous, but other chemotherapeutic agents can also cause serious cardiotoxicity and are not so well recognised. Examples include cyclophosphamide, ifosfamide, mitomycin and fluorouracil. Prediction and hence prophylaxis has always been a difficult task. Ideal monitoring techniques, upon which efficient prophylaxis depends, are yet to be determined. Current prophylaxis relies upon early detection of systolic and/or diastolic dysfunction. While somewhat useful, in some cases by the time defects are detected progression of chemotherapy-induced cardiomyopathy is beyond prevention. Prophylaxis would be much more efficient if a biochemical marker of myocardiocyte damage could be reliably used to stop further chemotherapy at the correct time before irreversible progressive 'macroscopic' damage becomes evident upon imaging. Work is currently progressing to identify the role of markers such as troponins and natriuretic peptides in this regard.

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.

Acute reversible cardiomyopathy and thromboembolism after cisplatin and 5-fluorouracil chemotherapy--a case report

Acute development of cardiomyopathy and occlusive thromboembolic events following cisplatin and 5-fluorouracil (5-FU) is rare but frequently lethal. The authors report the successful management of such an event in a 52-year-old man with squamous cell carcinoma of the soft palate. The possible pathophysiological mechanisms are discussed.

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.

Severe cardiotoxicity during 5-fluorouracil chemotherapy: a case and literature report

The chemotherapeutic agent 5-fluorouracil (5-FU) is a widely accepted part of many cancer treatment protocols. Its cardiotoxic potential is known, but considered uncommon and usually not life threatening, although some cases of severe cardiotoxicity related to 5-FU have been reported. The pathogenesis of cardiotoxicity caused by 5-FU is not clear. We report a case of sudden onset of severe cardiac failure, without ischemic symptoms or signs, during 5-FU treatment with serious consequences, in a previously healthy 23-year-old patient with squamous cell carcinoma of the tongue. Endomyocardial biopsy showed proliferation of the sarcoplasmic reticulum with marked vacuolization, similar to that found with doxorubicin cardiotoxicity. Because 5-FU cardiotoxicity is unpredictable and can have potentially fatal consequences, it requires, in our opinion, further clarification. With this well-documented case, including an endomyocardial biopsy, we hope to encourage additional efforts to investigate the pathophysiologic mechanisms of 5-FU cardiotoxicity.

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.

Fluorouracil cardiotoxicity

OBJECTIVE

To review the clinical manifestations, postulated mechanisms, and therapeutic implications of fluorouracil-induced cardiac toxicity.

DATA SOURCE

A MEDLINE search was used to identify pertinent literature.

STUDY SELECTION

Studies and case reports on fluorouracil cardiotoxicity were identified through a MEDLINE search. A manual review of bibliographies of identified articles was performed to ensure that all pertinent articles were included.

DATA EXTRACTION

Data pertaining to all aspects of fluorouracil cardiac toxicity, including pathogenesis, predisposing factors, clinical manifestations, and therapeutic implications, were evaluated.

DATA SYNTHESIS

Estimates from large series suggest a 1.6-2.3 percent incidence of clinically demonstrated cardiotoxicity. Predisposing factors include the presence of coronary artery disease and concurrent radiotherapy. Postulated mechanisms include direct myocardial ischemia, coronary spasm, or cardiotoxic impurities in fluorouracil formulation. Clinical manifestations include chest pain, nausea, diaphoresis with typical ischemic electrocardiographic (ECG) changes, relieved to normal after stopping the drug therapy. Nitrates and calcium-channel blockers do not protect against cardiotoxicity.

CONCLUSIONS

Fluorouracil cardiotoxicity may be much more common and clinically significant than previously thought. A high index of suspicion for cardiotoxicity must be maintained when the drug is administered, especially in the presence of heart disease and concomitant radiation therapy. In the presence of chest pain, it is mandatory to stop the infusion and, if possible, to replace fluorouracil with another chemotherapeutic agent.