Administration of angiotensin-converting enzyme inhibitors and β-blockers during adjuvant trastuzumab chemotherapy for nonmetastatic breast cancer: marker of risk or cardioprotection in the real world?

Addressing Cardiovascular Risk Across the Arc of a Woman's Life: Sex-Specific Prevention and Treatment

PURPOSE OF REVIEW

Cardiovascular disease (CVD) is the leading cause of morbidity and mortality in women in the United States of America. Despite this, women are underdiagnosed, less often receive preventive care, and are undertreated for CVD compared to men. There has been an increase in sex-specific risk factors and treatments over the past decade; however, sex-specific recommendations have not been included in the guidelines. We aim to highlight recent evidence behind the differential effect of traditional risk factors and underscore sex-specific risk factors with an intention to promote awareness, improve risk stratification, and early implementation of appropriate preventive therapies in women.

RECENT FINDINGS

Women are prescribed fewer antihypertensives and lipid-lowering agents and receive less cardiovascular care as compared to men. Additionally, pregnancy complications have been associated with increased cardiovascular mortality later in life. Findings from the ARIC study suggest that there is a perception of lower risk of cardiovascular disease in women. The SWEDEHEART study which investigated sex differences in treatment, noted a lower prescription of guideline-directed therapy in women. Women are less likely to be prescribed statin medications by their providers in both primary and secondary prevention as they are considered lower risk than men, while also being more likely to decline and discontinue treatment. A woman's abnormal response to pregnancy may serve as her first physiological stress test which can have implications on her future cardiovascular health. This was supported by the CHAMPs study noting a higher premature cardiovascular risk after maternal complications. Adverse pregnancy outcomes have been associated with a 1.5-4.0 fold increase in future cardiovascular events in multiple studies. In this review, we highlight the differences in traditional risk factors and their impact on women. Furthermore, we address the sex-specific risk factors and pregnancy-associated complications that increase the risk of CVD in women. Adherence to GDMT may have implications on overall mortality in women. An effort to improve early recognition of CVD risk with implementation of aggressive risk factor control and lifestyle modification should be emphasized. Future studies should specifically report on differences in outcomes between males and females. Increased awareness and knowledge on sex-specific risks and prevention are likely to lower the prevalence and improve outcomes of CVD in women.

Cardiotoxicity from neoadjuvant targeted treatment for breast cancer prior to surgery

Cancer treatment has been gradually shifting from non-specific cytotoxic agents to molecularly targeted drugs. Breast cancer (BC), a malignant tumor with one of the highest incidence worldwide, has seen a rapid development in terms of targeted therapies, leading to a radical change in the treatment paradigm. However, the use of targeted drugs is accompanied by an increasing rate of deaths due to non-tumor-related causes in BC patients, with cardiovascular complications as the most common cause. Cardiovascular toxicity during antitumor therapy has become a high-risk factor for survival in BC patients. Targeted drug-induced cardiotoxicity exerts a wide range of effects on cardiac structure and function, including conduction disturbances, QT interval prolongation, impaired myocardial contractility, myocardial fibrosis, and hypertrophy, resulting in various clinical manifestations, e.g., arrhythmias, cardiomyopathy, heart failure, and even sudden death. In adult patients, the incidence of antitumor targeted drug-induced cardiotoxicity can reach 50%, and current preclinical evaluation tools are often insufficiently effective in predicting clinical cardiotoxicity. Herein, we reviewed the current status of the occurrence, causative mechanisms, monitoring methods, and progress in the prevention and treatment of cardiotoxicity associated with preoperative neoadjuvant targeted therapy for BC. It supplements the absence of relevant review on the latest research progress of preoperative neoadjuvant targeted therapy for cardiotoxicity, with a view to providing more reference for clinical treatment of BC patients.

Cardiotoxicity of Epidermal Growth Factor Receptor 2-Targeted Drugs for Breast Cancer

Breast cancer is the most common form of cancer in women and its incidence has been increasing over the years. Human epidermal growth factor receptor 2 (HER2 or ErbB2) overexpression is responsible for 20 to 25% of invasive breast cancers, and is associated with poor prognosis. HER2-targeted therapy has significantly improved overall survival rates in patients with HER2-positive breast cancer. However, despite the benefits of this therapy, its cardiotoxicity is a major concern, especially when HER2-targeted therapy is used in conjunction with anthracyclines. At present, the mechanism of this cardiotoxicity is not fully understood. It is thought that HER2-targeting drugs inhibit HER2/NRG 1 dimer formation, causing an increase in ROS in the mitochondria of cardiomyocytes and inhibiting the PI3K/Akt and Ras/MAPK pathways, resulting in cell apoptosis. Antioxidants, ACE inhibitors, angiotensin II receptor blockers, β-blockers, statins and other drugs may have a cardioprotective effect when used with ErbB2-targeting drugs. NT-proBNP can be used to monitor trastuzumab-induced cardiotoxicity during HER2-targeted treatment and may serve as a biological marker for clinical prediction of cardiotoxicity. Measuring NT-proBNP is non-invasive, inexpensive and reproducible, therefore is worthy of the attention of clinicians. The aim of this review is to discuss the potential mechanisms, clinical features, diagnostic strategies, and intervention strategies related to cardiotoxicity of ErbB2-targeting drugs.

Conventional cardiac risk factors associated with trastuzumab-induced cardiotoxicity in breast cancer: Systematic review and meta-analysis

BACKGROUND

Trastuzumab has had a major impact on the treatment of human epidermal growth factor receptor 2 (HER2) positive breast cancer patients. However, it is associated with cardiotoxicity, expressed as an asymptomatic decrease in left ventricular ejection fraction (LVEF) and less often as clinical HF. The aim of this meta-analysis is to identify the association of conventional cardiovascular risk factors with the development of trastuzumab-induced cardiotoxicity (TIC).

METHODS

A literature search of PubMed was conducted to identify studies examining the association between cardiovascular risk factors and TIC. Data were extracted and pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated examining the odds of developing TIC for each of the risk factors.

RESULTS

A total of 35 studies were included in the analysis. Age (OR:0.7; 95%CI 0.318-1.09; P= 0.0004), hypertension (OR:0.69; 95%CI 0.26-1.12; P = 0.001), smoking(OR:0.35; 95%CI 0.01- 0.69; P = 0.038), diabetes mellitus (OR:0.44; 95%CI 0.24- 0.68; P = 0.0001) and family history of CAD (OR:5.51, 95%CI 1.76-17.25; P< 0.00001)were significantly associated with the development of cardiotoxicity. Known history of CAD (OR: 3.72; 95%CI 2.11-6.57; P = 0.0005) was also associated with the development of TIC.

CONCLUSION(S)

Identifying women at risk for TIC have several important potential applications. Clinicians may decide to assess LVEF more frequently in patients at highest risk for TIC in order to detect LV systolic dysfunction earlier. Additionally, this could help identify patients who would benefit most from prophylactic therapy for preventing TIC.

Predictors of new-onset heart failure and overall survival in metastatic breast cancer patients treated with liposomal doxorubicin

Cardiovascular diseases (CVDs) are the major cause of morbidity/mortality among breast cancer (BC) patients. Observation of the daily practice in eight experienced Polish oncology centers was conducted to find all possible predictors of new cases of heart failure (HF) and overall survival (OS) of metastatic BC patients treated with liposomal doxorubicin, taking into account the impact of pre-existing CVDs. HF was the cause of premature discontinuation of liposomal doxorubicin therapy in 13 (3.2%) of 402 patients. The probability of developing HF was higher in women with pre-existing CVDs (HR 4.61; 95%CI 1.38–15.38). Independent of CVDs history, a lower risk of HF was observed in those treated with a cumulative dose of liposomal doxorubicin > 300 mg/m2 (HR 0.14; 95% CI 0.04–0.54) and taxane-naive (HR 0.26; 95% CI 0.07–0.96). Multivariate analysis including the presence of pre-existing CVDs and occurrence of new HF, revealed a liposomal doxorubicin in cumulative doses of > 300 mg/m2 as a beneficial predictor for OS (HR 0.61; 95% CI 0.47–0.78) independently of subsequent chemotherapy (HR 0.72; 95% CI 0.57–0.92) or endocrine therapy (HR 0.65; 95% CI 0.49–0.87). Higher doses of liposomal doxorubicin can decrease mortality in metastatic BC without increasing the risk of HF. The clinical benefit is achieved regardless of pre-existing CVDs and subsequent anticancer therapy.

Cardiovascular Outcomes in Relation to Antihypertensive Medication Use in Women with and Without Cancer: Results from the Women's Health Initiative

BACKGROUND

Recent clinical trials have evaluated angiotensin-converting enzyme (ACE) inhibitors (ACEis), angiotensin receptor blockers (ARBs), and beta blockers (BBs) in relation to cardiotoxicity in patients with cancer, typically defined by ejection fraction declines. However, these trials have not examined long-term, hard clinical endpoints. Within a prospective study, we examined the risk of heart failure (HF) and coronary heart disease (CHD) events in relation to use of commonly used antihypertensive medications, including ACEis/ARBs, BBs, calcium channel blockers (CCB), and diuretics, comparing women with and without cancer.

MATERIALS AND METHODS

In a cohort of 56,997 Women's Health Initiative study participants free of cardiovascular disease who received antihypertensive treatment, we used multivariable-adjusted Cox regression models to calculate the hazard ratios (HRs) of developing CHD, HF, and a composite outcome of cardiac events (combining CHD and HF) in relation to use of ACEis/ARBs, CCBs, or diuretics versus BBs, separately in women with and without cancer.

RESULTS

Whereas there was no difference in risk of cardiac events comparing ACEi/ARB with BB use among cancer-free women (HR = 0.99 [0.88-1.12]), among cancer survivors ACEi/ARB users were at a 2.24-fold risk of total cardiac events (1.18-4.24); p-interaction = .06). When investigated in relation to CHD only, an increased risk was similarly observed in ACEi/ARB versus BB use for cancer survivors (HR = 1.87 [0.88-3.95]) but not in cancer-free women (HR = 0.91 [0.79-1.06]; p-interaction = .04). A similar pattern was also seen in relation to HF but did not reach statistical significance (p-interaction = .23).

CONCLUSION

These results from this observational study suggest differing risks of cardiac events in relation to antihypertensive medications depending on history of cancer. Although these results require replication before becoming actionable in a clinical setting, they suggest the need for more rigorous examination of the effect of antihypertensive choice on long-term cardiac outcomes in cancer survivors.

IMPLICATIONS FOR PRACTICE

Although additional research is needed to replicate these findings, these data from a large, nationally representative sample of postmenopausal women indicate that beta blockers are favorable to angiotensin-converting enzyme inhibitors in reducing the risk of cardiac events among cancer survivors. This differs from the patterns observed in a noncancer cohort, which largely mirrors what is found in the randomized clinical trials in the general population.

Concomitant use of renin-angiotensin-aldosterone system inhibitors prevent trastuzumab-induced cardiotoxicity in HER2+ breast cancer patients: an institutional retrospective study

Background

Cardiotoxicity is an adverse effect of trastuzumab (TRA) in the treatment of human epidermal growth factor 2 positive (HER2+) breast cancer. Current literature on the cardioprotective effects of agents targeted against the renin-angiotensin-aldosterone system (RAAS) and beta-blockers (BB) in TRA-treated HER2+ breast cancer patients is conflicting. We hypothesized that concurrent use of RAAS inhibitors would prevent TRA-induced cardiotoxicity (TIC).

Methods and materials

Surveillance ejection fraction (EF) at 3-month intervals up to 36 months obtained from echocardiogram or multigated acquisition (MUGA) scans were retrospectively compared to baseline EF in TRA-treated HER2+ breast cancer patients between 2011 to 2016 at a tertiary cancer center. TIC was defined as a decrease of EF by more than 15 EF percentage points from baseline on surveillance imaging. Cardiac medications and comorbidities were compared between patients with reduced EF secondary to TIC (rEF) and patients who did not experience TIC (pEF). A published clinical risk score (CRS) was applied to the patient population with calculated sensitivity analyses to determine if the CRS could predict TIC.

Results

Of 127 patients with TRA-treated HER2+ breast cancer, 11% developed cardiotoxicity resulting in discontinuation of TRA. Cardiotoxicity with reduced EF was seen as early as 3 months and at subsequent 3-month follow up intervals up to the 15-month follow-up. Co-existing arrhythmia, coronary artery disease (CAD), hypertension (HTN) and diabetes mellitus (DM) tended to infer an increased risk for cardiotoxicity. Patients with pEF were found to be concurrently on a RAAS inhibitor more than the rEF group (OR of 0.24, 95% CI 0.05-1.11, p 0.06). The CRS high-risk cut-off had a sensitivity of 0.17 (95% CI 0.03-0.49), specificity of 0.89 (95% CI 0.82-0.94), positive predictive value of 0.14 (95% CI 0.03-0.44) and negative predictive value of 0.91 (95% CI 0.84-0.95).

Conclusion

Our data suggest that the concurrent use of a RAAS inhibitors during TRA treatment may provide a protective effect against TIC and warrants further investigation. The low sensitivity and positive predictive value demonstrated that the CRS has minimal utility as a screening tool for prediction of patients at high risk for TIC. Therefore, closer surveillance of patients receiving TRA is warranted for early detection of TIC.

Prevention of Trastuzumab and Anthracycline-induced Cardiotoxicity Using Angiotensin-converting Enzyme Inhibitors or β-blockers in Older Adults With Breast Cancer

PURPOSE

Although clinical trials have provided some data on the benefit of angiotensin-converting enzyme inhibitors (ACEIs) or β-blockers (BBs) in patients with chemotherapy-induced cardiotoxicity, evidence of ACEIs/BBs on prevention of trastuzumab and/or anthracycline-induced cardiotoxicity outside trials is limited.

MATERIALS AND METHODS

A cohort study of 142,990 women (66 y and above) newly diagnosed with breast cancer from 2001 to 2009 was conducted using the Surveillance, Epidemiology, and End Results-Medicare-linked database. The ACEI/BB exposure was defined as filled prescription(s) before or after the initiation of trastuzumab/anthracyclines. The nonexposed group was defined as those who had never been prescribed ACEIs/BBs. Cumulative rates of cardiotoxicity and all-cause mortality were estimated and marginal structural Cox models were used to determine factors associated with cardiotoxicity and all-cause mortality adjusting for baseline covariates and use of chemotherapy. All statistical tests were 2 sided.

RESULTS

The final sample included 6542 women. Adjusted hazard ratio for cardiotoxicity and all-cause mortality for the ACEI/BB exposed group were 0.77 (95% confidence interval, 0.62-0.95) and 0.79 (95% confidence interval, 0.70-0.90) compared with the nonexposed group, respectively. Starting ACEIs/BBs≤6 months after the initiation of trastuzumab/anthracyclines and having exposed duration≥6 months were also associated with decreased risk of cardiotoxicity and all-cause mortality. Baseline characteristics, including age, non-Hispanic black, advanced cancer, region, comorbidity, preexisting cardiovascular conditions, lower socioeconomic status, and concomitant treatment were significantly associated with an elevated risk of all-cause mortality and/or cardiotoxicity (all P<0.05).

CONCLUSIONS

ACEIs/BBs show favorable effects on preventing cardiotoxicity and improving survival in female breast cancer patients undergoing trastuzumab/anthracycline treatment.

Chemotherapy-related cardiac dysfunction: grey area in type I and type II classification

PURPOSE OF REVIEW

The main aim of this review is to address and challenge an old nomenclature of reversible versus irreversible chemotherapy-induced cardiomyopathy.

RECENT FINDINGS

Chemotherapy-related cardiac dysfunction (CRCD) has been often characterized as type I or type II. Type I CRCD (e.g., anthracycline) represents a group of chemotherapeutic agents that has often been correlated with irreversible cardiac dysfunction. Conversely, type II CRCD (e.g., trastuzumab) represents a group of anticancer agents that has been considered as reversible. Recent evidence suggests that this nomenclature may not hold true, thus affecting clinical prognosis as well as timely management. It is prudent to address this concern so that physicians are armed with appropriate information, thus providing our oncological patients with informed care. The purpose is to highlight the grey area in this dichotomous classification.

SUMMARY

Type I CRCD can be reversible if cardioprotective medications are administered in a timely manner. Conversely, a small proportion of type II CRCD may develop irreversible dysfunction and therefore, will require a long-term follow-up. Therefore, every case should be dealt on an individual basis and an appropriate prognosis should be given to patients based on the clinical evidence on hand.

Anticancer drugs-related QTc prolongation, torsade de pointes and sudden death: current evidence and future research perspectives

Anticancer drugs may have proarrhythmic effects including drug-induced QT interval prolongation, which is of particular importance because it can lead to a fatal polymorphic ventricular tachycardia termed torsade de pointes (TdP). QT interval prolongation and TdP are rare life-threatening untoward effects of anticancer therapy, particularly with arsenic trioxides and anthracyclines, and even some novel molecular targeted drugs touted as 'tumor specific'. Several factors that affect myocardial repolarization can further increase the risk of TdP. This article reviews the mechanism of QT interval prolongation, risk factors for TdP and the QT toxicity of anticancer drugs as well as its management. Specific attention should be paid to high-risk populations such as patients with underlying heart diseases, electrolyte imbalance and bradycardia. To minimize the occurrence of QT interval prolongation and TdP, it is advisable to conduct a careful risk factor assessment before antitumor therapy. To this end, several new biomarkers have been introduced to predict TdP triggering and recent studies have pointed out the potential clinical relevance of genetic testing.

Cardiovascular Disease and Breast Cancer: Where These Entities Intersect: A Scientific Statement From the American Heart Association

Cardiovascular disease (CVD) remains the leading cause of mortality in women, yet many people perceive breast cancer to be the number one threat to women's health. CVD and breast cancer have several overlapping risk factors, such as obesity and smoking. Additionally, current breast cancer treatments can have a negative impact on cardiovascular health (eg, left ventricular dysfunction, accelerated CVD), and for women with pre-existing CVD, this might influence cancer treatment decisions by both the patient and the provider. Improvements in early detection and treatment of breast cancer have led to an increasing number of breast cancer survivors who are at risk of long-term cardiac complications from cancer treatments. For older women, CVD poses a greater mortality threat than breast cancer itself. This is the first scientific statement from the American Heart Association on CVD and breast cancer. This document will provide a comprehensive overview of the prevalence of these diseases, shared risk factors, the cardiotoxic effects of therapy, and the prevention and treatment of CVD in breast cancer patients.

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

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

Improving the preclinical models for the study of chemotherapy-induced cardiotoxicity: a Position Paper of the Italian Working Group on Drug Cardiotoxicity and Cardioprotection

Although treatment for heart failure induced by cancer therapy has improved in recent years, the prevalence of cardiomyopathy due to antineoplastic therapy remains significant worldwide. In addition to traditional mediators of myocardial damage, such as reactive oxygen species, new pathways and target cells should be considered responsible for the impairment of cardiac function during anticancer treatment. Accordingly, there is a need to develop novel therapeutic strategies to protect the heart from pharmacologic injury, and improve clinical outcomes in cancer patients. The development of novel protective therapies requires testing putative therapeutic strategies in appropriate animal models of chemotherapy-induced cardiomyopathy. This Position Paper of the Working Group on Drug Cardiotoxicity and Cardioprotection of the Italian Society of Cardiology aims to: (1) define the distinctive etiopatogenetic features of cardiac toxicity induced by cancer therapy in humans, which include new aspects of mitochondrial function and oxidative stress, neuregulin-1 modulation through the ErbB receptor family, angiogenesis inhibition, and cardiac stem cell depletion and/or dysfunction; (2) review the new, more promising therapeutic strategies for cardioprotection, aimed to increase the survival of patients with severe antineoplastic-induced cardiotoxicity; (3) recommend the distinctive pathological features of cardiotoxicity induced by cancer therapy in humans that should be present in animal models used to identify or to test new cardioprotective therapies.

Trastuzumab and target-therapy side effects: Is still valid to differentiate anthracycline Type I from Type II cardiomyopathies?

The improvement in cancer therapy and the increasing number of long term survivors unearth the issue of cardiovascular side effects of anticancer treatments. As a paradox in cancer survivors, delayed cardiotoxicity has emerged as a significant problem. Two categories of cardiotoxic side effects of antineoplastic drugs have been previously proposed: Type I cardiotoxicity, defined as permanent cardiotoxicity, is usually caused by anthracyclines; Type II cardiotoxicity, considered as reversible cardiotoxicity, has been mainly related to monoclonal antibodies. The cardiotoxicity of antibodies has been associated to trastuzumab, a humanized anti-ErbB2 monoclonal antibody currently in clinical use for the therapy of breast carcinomas, which induces cardiac dysfunction when used in monotherapy, or in combination with anthracyclines. Furthermore, recent retrospective studies have shown an increased incidence of heart failure and/or cardiomyopathy in patients treated with trastuzumab, that can persist many years after the conclusion of the therapy, thus suggesting that the side toxic effects are not always reversible as it was initially proposed. On the other hand, early detection and prompt therapy of anthracycline associated cardiotoxicity can lead to substantial recovery of cardiac function. On the basis of these observations, we propose to find a new different classification for cardiotoxic side effects of drugs used in cancer therapy.

Breast cancer therapy and cardiovascular risk: focus on trastuzumab

Breast cancer is the most common cancer in the UK. Advances in the methods of early diagnosis as well as newer and more effective treatments have led to improvements of disease-free and overall survival over the last decade. Almost one-third of breast cancers present with an aggressive form characterized by increased expression of human epidermal growth receptor 2 (HER2) proteins. A targeted treatment using monoclonal antibodies against HER2 expression such as trastuzumab has been shown to improve survival. Unfortunately, there is a degree of cardiotoxicity associated with these agents, as inhibition of HER2 pathways can also impair cardioprotective pathways. In the present review, we discuss the mechanisms by which trastuzumab might affect vascular homeostasis leading to endothelial dysfunction. We also provide suggestions for future research examining the effects of trastuzumab on the vasculature in breast cancer.

Fully human HER2/cluster of differentiation 3 bispecific antibody triggers potent and specific cytotoxicity of T lymphocytes against breast cancer

The use of a bispecific antibody (BsAb) is a promising and highly specific approach to cancer therapy. In the present study, a fully human recombinant single chain variable fragment BsAb against human epidermal growth factor receptor (HER)2 and cluster of differentiation (CD)3 was constructed with the aim of developing an effective treatment for breast cancer. HER2/CD3 BsAb was expressed in Chinese hamster ovary cells and purified via nickel column chromatography. Flow cytometry revealed that the HER2/CD3 BsAb was able to specifically bind to HER2 and CD3-positive cells. HER2/CD3 BsAb was able to stimulate T-cell activation and induce the lysis of cultured SKBR-3 and BT474 cells in the presence of unstimulated T lymphocytes. HER2/CD3 BsAb efficiently inhibited the growth of breast cancer tissue by activating and inducing the proliferation of tumor tissue infiltrating lymphocytes. Therefore, HER2/CD3 BsAb is a potent tool which may be a suitable candidate for the treatment of breast cancer.

Evaluation, prevention and management of cancer therapy-induced cardiotoxicity: a contemporary approach for clinicians

PURPOSE OF REVIEW

While targeted therapies have improved cancer outcomes, unique cardiovascular toxicities are increasingly recognized, particularly when administered sequentially after anthracyclines or radiation. Patients with cancer therapy-induced cardiotoxicity benefit from collaborative care involving cardiology and oncology, leading to a new interdisciplinary field called cardio-oncology. The present review will highlight contemporary clinical issues in cardio-oncology.

RECENT FINDINGS

Recently, risk factors for cancer therapy-induced cardiotoxicity have been evaluated in real-world rather than in clinical trial patients. Biomarkers and advanced echocardiography are emerging as sensitive tools for preclinical identification of cancer therapy-induced cardiotoxicity. Single-center studies suggest that cancer therapy-induced cardiotoxicity responds to prompt heart failure medical treatment, and such therapy may even prevent cardiotoxicity.

SUMMARY

Modern cancer therapy has short-term cardiac risk that may require collaborative management by clinicians with expertise in cardiology and oncology. The increased effectiveness of modern cancer therapy is resulting in a growing population of cancer survivors who are at long-term risk for cardiovascular disease. The present review of contemporary clinical issues in cardio-oncology will be of interest to healthcare providers who manage cardiotoxicity during cancer therapy, and who follow patients who survive cancer but face increased long-term cardiovascular risk.

Cardiac risk in the treatment of breast cancer: assessment and management

As the number of long-term breast cancer survivors has increased, the side effects of adjuvant cancer therapy, such as cardiac toxicity, remain clinically important. Although the cardiac toxicity due to anthracyclines, radiotherapy, or trastuzumab is well-documented, several issues need to be clarified and are the subjects of extensive ongoing clinical research. This review summarizes the incidence of cardiac toxicity due to breast cancer adjuvant therapy and highlights the current trends in early detection and management of cardiac toxicities.

Chemotherapy-Induced Cardiotoxicity: Pathophysiology and Prevention

Along with the remarkable progress registered in oncological treatment that led to increased survival of cancer patients, treatment-related comorbidities have also become an issue for these long-term survivors. Of particular interest is the development of cardiotoxic events, which, even when asymptomatic, not only have a negative impact on the patient`s cardiac prognosis, but also considerably restrict therapeutic opportunities. The pathophysiology of cytostatic-induced cardiotoxicity implies a series of complex and intricate mechanisms, whose understanding enables the development of preventive and therapeutic strategies. Securing cardiac function is an ongoing challenge for the pharmaceutical industry and the physicians who have to deal currently with these adverse reactions. This review focuses on the main mechanism of cardiac toxicity induced by anticancer drugs and especially on the current strategies applied for preventing and minimizing the cardiac side effects.

Cardiovascular events, early discontinuation of trastuzumab, and their impact on survival

To evaluate how often trastuzumab therapy is ended early (i.e., early discontinuation) and how cardiovascular events and early discontinuation affect survival among older women with breast cancer. A population-based cohort of female Medicare beneficiaries with stage I-III breast cancer in 2005-2009 who received trastuzumab was assembled and followed through 2011. Completed trastuzumab treatment was defined as ≥11 months of continuous trastuzumab treatments with no delay between trastuzumab treatments >45 days. We identified trastuzumab-associated cardiovascular events as those occurring within 45 days before or after the last trastuzumab treatment. Using Cox proportional hazard models, we examined the association between early discontinuation of trastuzumab and cardiovascular events on all-cause mortality. Our cohort consisted of 585 women (mean age: 71.6 years). Approximately 41 % of women discontinued trastuzumab therapy early. Patients with early discontinuation of trastuzumab were more likely to have heart failure /cardiomyopathy, atrial fibrillation, and other cardiovascular events than women who completed trastuzumab. Cardiovascular events were strongly associated with an increased risk of all-cause mortality [adjusted hazard ratio (AHR) 3.54; 95 % confidence interval (CI) 1.87 to 6.68]. Women with early discontinuation of trastuzumab had a non-significant increase in risk of all-cause mortality (AHR: 1.74; 95 % CI 0.94 to 3.23), compared to women who completed trastuzumab. Early trastuzumab discontinuation was common among older patients, and often associated with adverse cardiovascular events. Development of cardiovascular events was associated with a higher mortality risk than early trastuzumab discontinuation, implying that reducing cardiovascular complications from trastuzumab therapy could likely have a substantive impact on overall survival in this population.

Risk prediction model for heart failure and cardiomyopathy after adjuvant trastuzumab therapy for breast cancer

BACKGROUND

Adjuvant trastuzumab improves survival for women with human epidermal growth factor receptor 2-positive breast cancer, but increases risk for heart failure (HF) and cardiomyopathy (CM). However, clinical trials may underestimate HF/CM risk because they enroll younger subjects with fewer cardiac risk factors. We sought to develop a clinical risk score that identifies older women with breast cancer who are at higher risk of HF or CM after trastuzumab.

METHODS AND RESULTS

Using the Surveillance, Epidemiology and End Results (SEER)-Medicare database, we identified women with breast cancer who received adjuvant trastuzumab. Using a split-sample design, we used a proportional hazards model to identify candidate predictors of HF/CM in a derivation cohort. A risk score was constructed using regression coefficients, and HF/CM rates were calculated in the validation cohort. The sample consisted of 1664 older women (mean age 73.6 years) with 3-year HF/CM rate of 19.1%. A risk score consisting of age, adjuvant chemotherapy, coronary artery disease, atrial fibrillation or flutter, diabetes mellitus, hypertension, and renal failure was able to classify HF/CM risk into low (0 to 3 points), medium (4 to 5 points), and high (≥6 points) risk strata with 3-year rates of 16.2%, 26.0%, and 39.5%, respectively.

CONCLUSIONS

A 7-factor risk score was able to stratify 3-year risk of HF/CM after trastuzumab between the lowest and highest risk groups by more than 2-fold in a Medicare population. These findings will inform future research aimed at further developing a clinical risk score for HF/CM for breast cancer patients of all ages.