Increased long QT and torsade de pointes reporting on tamoxifen compared with aromatase inhibitors

Comprehensive review of non-invasive-treatment-related cardiovascular toxicity in breast cancer

Cardiovascular toxicity is a significant side effect of breast cancer treatment and has emerged as a leading cause of non-tumor-related deaths among breast cancer survivors, emphasizing the critical need for effective monitoring and management of these complications. As breast cancer remains the most prevalent cancer among women, advancements in survival rates have been achieved through treatments such as chemotherapy, targeted therapy, endocrine therapy, immunotherapy, and radiotherapy. This review provides a comprehensive understanding of the cardiovascular toxicity mechanisms associated with both established and emerging breast cancer therapies, identifies potential therapeutic targets and monitoring strategies, and highlights key deficiencies and challenges in the field. By offering insights into the early detection, prevention, and management of cardiovascular complications, this review aims to guide future research directions and clinical practices, ultimately improving outcomes for breast cancer patients.

Letrozole-induced reversible acute heart failure

IntroductionLetrozole is an aromatase inhibitor (AI), which suppresses plasma estrogen levels by inhibiting the aromatase enzyme, that causes the conversion of androgens to estrogen in peripheral tissues. There is very few information in the literature regarding the development of acute heart failure after AI use. We would like to report a case of a patient who was started letrozole for hormonal treatment and developed acute heart failure due to this.Case reportFifty-seven-year-old woman with hormone positive breast cancer was operated after neoadjuvant chemotherapy and received radiotherapy. Letrozole treatment was initiated after radiotherapy and the patient presented to the emergency department after two weeks with cough and dyspnea. Ejection fraction decreased to 20% and acute heart failure developed.Management and outcomeLetrozole treatment was stopped. Afterwards, improvement in the patient's cardiac functions was observed. Letrozole-induced heart failure was thought to be reversible.DiscussionLetrozole is one of the most commonly used HT in the treatment of hormone positive breast cancer. It may rarely cause cardiac side effects. It is very important to make patients aware of these issues and to be consulted by cardiology in case of possible cardiac symptoms.

Atrial Fibrillation in Patients with Breast Cancer: A Literature Review

In addition to traditional risk factors, patients with breast cancer are at an increased risk of atrial fibrillation due to cancer itself and certain cancer therapies. Atrial fibrillation in these patients adds to their morbidity and mortality. The precise mechanisms leading to the increased atrial fibrillation in patients with breast cancer are not well understood. The main goal of atrial fibrillation management in this population is to facilitate uninterrupted cancer treatment while addressing the arrhythmia and other cardiovascular sequelae of cancer treatment. Rhythm control is often challenging to implement in patients with breast cancer during active antineoplastic therapy because of the need for uninterrupted anticoagulation, potential drug-drug interactions between cancer treatments and antiarrhythmic medications, and the increased likelihood of atrial fibrillation recurrence. Prevention of thromboembolism and anticoagulation can also be challenging in patients with breast cancer as a result of the increased risk of cancer-related procoagulant state and coagulopathies. The integration of a cardio-oncology team and a multidisciplinary approach are crucial for better outcomes. The therapeutic interventions should be tailored toward individual patients' profiles through a shared decision-making approach. The precise mechanisms leading to the increased atrial fibrillation in patients with breast cancer are not well understood, highlighting the gaps in our knowledge. More research is required to reduce these gaps, refine risk stratification, and optimize treatment strategies in these patients.

Management of Cardiac Rhythm Disorders in Cardio-oncology

Arrhythmias and cancer are two pathological conditions that often coexist due to a patient's pre-existing comorbidities, or toxicity linked to anti-neoplastic drugs, and both are often characterised by poor prognosis. Cardio-oncology is a new interdisciplinary field that focuses on the cardiovascular health of cancer patients, especially those undergoing cancer treatment. Furthermore, cardiotoxicity can cause arrhythmias through primary and secondary mechanisms. Chemotherapy drugs have been shown to directly affect molecular pathways associated with arrhythmia development, as well as indirectly through mechanisms involving ischaemia or inflammatory injury to the heart. Understanding how to prevent and to treat these electrophysiological issues in cancer is an important challenge for cardio-oncologists. This review explores the intersection between cardio-oncology and electrophysiology, the various cardiac cell types implicated in the development of arrhythmias during cancer, the interplay between arrhythmias and cancer pathogenesis, and the need for the implantation of electronic devices along with their associated risks.

Cardiovascular complications of ribociclib in breast cancer patients

Cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitors have unprecedentedly advanced hormone-dependent breast cancer treatment paradigm. In the metastatic setting, ribociclib has consistently demonstrated survival benefit in pre-, peri-, and postmenopausal patients, conjugating efficacy with health-related quality of life preservation. Accordingly, the emergence of cardiac and/or vascular adverse events related to this novel targeted agent is gaining significant interest. This narrative review provides an overview of the incidence and spectrum of cardiovascular toxicity, in both clinical trial framework and real-world evidence. The potential pathogenetic mechanism, along with the available diagnostic parameters including biomarkers, and proper management, are also summarized.

Cardiotoxicity of Agents Used in Patients With Breast Cancer

Cancer and cardiovascular diseases are the two major causes of mortality, morbidity, and disability worldwide. The improvement in effective therapeutic options for the management of breast cancer (BC) has led to an increased number of BC survivors, who can experience long-term toxicities from cancer treatments. Adverse events including cardiovascular toxicities must be considered in light of effectiveness of recently approved drugs for BC treatment, including elacestrant, tucatinib, neratinib, olaparib, the immune checkpoint inhibitors, trastuzumab deruxtecan, or sacituzumab govitecan. Many cancer drugs affect the cardiovascular system with a range of clinical manifestations. Prompt diagnosis and treatment as well as a multidisciplinary approach involving a cardio-oncologist is optimal for management of these cardiovascular events.

Tamoxifen induced cardiac damage via the IL-6/p-STAT3/PGC-1α pathway

Tamoxifen (TAM) is an effective anticancer drug for breast and ovarian cancer. However, increased risk of cardiotoxicity is a long-term clinical problem associated with TAM, while the underlying mechanisms remain unclear. Here, we performed experiments in cardiomyocytes and tumor-bearing or nontumor-bearing mice, and demonstrated that TAM induced cardiac injury via the IL-6/p-STAT3/PGC-1α/IL-6 feedback loop, which is responsible for reactive oxygen species (ROS) accumulation. Compared with non-tumor bearing mice, tumor-bearing mice showed stronger cardiac toxicity after TAM injection, although there was no significant difference. In vitro experiments demonstrated STAT3 phosphorylation inhibitor can increase PGC-1α expression and protect cardiomyocyte via decreasing ROS. Since tumor has higher STAT3 phosphorylation and IL-6 expression level, our research results indicated combining TAM and STAT3 inhibitor might be an effective treatment strategy which can provide both tumor killing and cardioprotective function. Further in vivo research is needed to fully elucidate the effect and mechanisms of the combination therapy of TAM and STAT3 inhibitor.

Tailored to a Woman's Heart: Gender Cardio-Oncology Across the Lifespan

PURPOSE OF REVIEW

Females outnumber males among long-term cancer survivors, primarily as a result of the prevalence of breast cancer. Late cardiovascular effects of cancer develop over several decades, which for many women, may overlap with reproductive and lifecycle events. Thus, women require longitudinal cardio-oncology care that anticipates and responds to their evolving cardiovascular risk.

RECENT FINDINGS

Women may experience greater cardiotoxicity from cancer treatments compared to men and a range of treatment-associated hormonal changes that increase cardiometabolic risk. Biological changes at critical life stages, including menarche, pregnancy, and menopause, put female cancer patients and survivors at a unique risk of cardiovascular disease. Women also face distinct psychosocial and physical barriers to accessing cardiovascular care. We describe the need for a lifespan-based approach to cardio-oncology for women. Cardio-oncology care tailored to women should rigorously consider cancer treatment/outcomes and concurrent reproductive/hormonal changes, which collectively shape quality of life and cardiovascular outcomes.

A Novel Quantitative Electrocardiography Strategy Reveals the Electroinhibitory Effect of Tamoxifen on the Mouse Heart

Tamoxifen, a selective estrogen receptor modulator, was initially used to treat cancer in women and more recently to induce conditional gene editing in rodent hearts. However, little is known about the baseline biological effects of tamoxifen on the myocardium. In order to clarify the short-term effects of tamoxifen on cardiac electrophysiology of myocardium, we applied a single-chest-lead quantitative method and analyzed the short-term electrocardiographic phenotypes induced by tamoxifen in the heart of adult female mice. We found that tamoxifen prolonged the PP interval and caused a decreased heartbeat, and further induced atrioventricular block by gradually prolonging the PR interval. Further correlation analysis suggested that tamoxifen had a synergistic and dose-independent inhibition on the time course of the PP interval and PR interval. This prolongation of the critical time course may represent a tamoxifen-specific ECG excitatory-inhibitory mechanism, leading to a reduction in the number of supraventricular action potentials and thus bradycardia. Segmental reconstructions showed that tamoxifen induced a decrease in the conduction velocity of action potentials throughout the atria and parts of the ventricles, resulting in a flattening of the P wave and R wave. In addition, we detected the previously reported prolongation of the QT interval, which may be due to a prolonged duration of the ventricular repolarizing T wave rather than the depolarizing QRS complex. Our study highlights that tamoxifen can produce patterning alternations in the cardiac conduction system, including the formation of inhibitory electrical signals with reduced conduction velocity, implying its involvement in the regulation of myocardial ion transport and the mediation of arrhythmias. A Novel Quantitative Electrocardiography Strategy Reveals the Electroinhibitory Effect of Tamoxifen on the Mouse Heart（Figure 9）. A working model of tamoxifen producing acute electrical disturbances in the myocardium. SN, sinus node; AVN, atrioventricular node; RA, right atrium; LA, left atrium; RV, right ventricle; LV, left ventricle.

Radiation therapy in the thoracic region: Radio-induced cardiovascular disease, cardiac delineation and sparing, cardiac dose constraints, and cardiac implantable electronic devices

Radiation therapy in the thoracic region may deliver incidental ionizing radiation to the surrounding healthy structures, including the heart. Radio-induced heart toxicity has long been a concern in breast cancer and Hodgkin's lymphoma and was deemed a long-term event. However, recent data highlight the need to limit the dose to the heart in less favorable thoracic cancers too, such as lung and esophageal cancers in which incidental irradiation led to increased mortality. This article will summarize available cardiac dose constraints in various clinical settings and the types of radio-induced cardiovascular diseases encountered as well as delineation of cardiac subheadings and management of cardiac devices. Although still not completely deciphered, heart dose constraints remain intensively investigated and the mean dose to the heart is no longer the only dosimetric parameter to consider since the left anterior descending artery as well as the left ventricle should also be part of dosimetry constraints.

New Insights on the Toxicity on Heart and Vessels of Breast Cancer Therapies

Cardiovascular diseases are largely represented in patients with cancer and appear to be important side effects of cancer treatments, heavily affecting quality of life and leading to premature morbidity and death among cancer survivors. In particular, treatments for breast cancer have been shown to potentially play serious detrimental effects on cardiovascular health. This review aims to explore the available literature on breast cancer therapy-induced side effects on heart and vessels, illustrating the molecular mechanisms of cardiotoxicity known so far. Moreover, principles of cardiovascular risk assessment and management of cardiotoxicity in clinical practice will also be elucidated. Chemotherapy (anthracycline, taxanes, cyclophosphamide and 5-fluorouracil), hormonal therapy (estrogen receptor modulator and gonadotropin or luteinizing releasing hormone agonists) and targeted therapy (epidermal growth factor receptor 2 and Cyclin-dependent kinases 4 and 6 inhibitors) adverse events include arterial and pulmonary hypertension, supraventricular and ventricular arrhythmias, systolic and diastolic cardiac dysfunction and coronary artery diseases due to different and still not well-dissected molecular pathways. Therefore, cardiovascular prevention programs and treatment of cardiotoxicity appear to be crucial to improve morbidity and mortality of cancer survivors.

Cardio-oncology in Austria: cardiotoxicity and surveillance of anti-cancer therapies : Position paper of the Heart Failure Working Group of the Austrian Society of Cardiology

Survival in cancer is continuously improving due to evolving oncological treatment. Therefore, cardiovascular short-term and long-term side effects gain crucial importance for overall outcome. Cardiotoxicity not only presents as heart failure, but also as treatment-resistant hypertension, acute coronary ischemia with plaque rupture or vasospasm, thromboembolism, arrhythmia, pulmonary hypertension, diastolic dysfunction, acute myocarditis and others. Recent recommendations have proposed baseline cardiac risk assessment and surveillance strategies. Major challenges are the availability of monitoring and imaging resources, including echocardiography with speckle tracking longitudinal strain (GLS), serum biomarkers such as natriuretic peptides (NT-proBNP) and highly sensitive cardiac troponins. This Austrian consensus encompasses cardiotoxicity occurrence in frequent antiproliferative cancer drugs, radiotherapy, immune checkpoint inhibitors and cardiac follow-up considerations in cancer survivors in the context of the Austrian healthcare setting. It is important to optimize cardiovascular risk factors and pre-existing cardiac diseases without delaying oncological treatment. If left ventricular ejection fraction (LVEF) deteriorates during cancer treatment (from >10% to <50%), or myocardial strain decreases (>15% change in GLS), early initiation of cardioprotective therapies (angiotensin-converting enzyme inhibitors, angiotensin or beta receptor blockers) is recommended, and LVEF should be reassessed before discontinuation. Lower LVEF cut-offs were recently shown to be feasible in breast cancer patients to enable optimal anticancer treatment. Interdisciplinary cardio-oncology cooperation is pivotal for optimal management of cancer patients.

Cardio-Oncology Drug Interactions: A Scientific Statement From the American Heart Association

In the cardio-oncology population, drug interactions are of particular importance given the complex pharmacological profile, narrow therapeutic index, and inherent risk of therapies used to manage cardiovascular disease and cancer. Drug interactions may be beneficial or detrimental to the desired therapeutic effect. Clinicians in both cardiology and oncology should be cognizant of these potential drug-drug interactions that may reduce the efficacy or safety of either cardiovascular or cancer therapies. These risks can be mitigated through increased recognition of potential drug-drug interaction, use of alternative medications when possible, and careful monitoring. This scientific statement provides clinicians with an overview of pharmacodynamic and pharmacokinetic drug-drug interactions in patients with cancer exposed to common cardiovascular and cancer medications.

Sex-Specific Cardiovascular Risks of Cancer and Its Therapies

In both cardiovascular disease and cancer, there are established sex-based differences in prevalence and outcomes. Males and females may also differ in terms of risk of cardiotoxicity following cancer therapy, including heart failure, cardiomyopathy, atherosclerosis, thromboembolism, arrhythmias, and myocarditis. Here, we describe sex-based differences in the epidemiology and pathophysiology of cardiotoxicity associated with anthracyclines, hematopoietic stem cell transplant (HCT), hormone therapy and immune therapy. Relative to males, the risk of anthracycline-induced cardiotoxicity is higher in prepubertal females, lower in premenopausal females, and similar in postmenopausal females. For autologous hematopoietic cell transplant, several studies suggest an increased risk of late heart failure in female lymphoma patients, but sex-based differences have not been shown for allogeneic hematopoietic cell transplant. Hormone therapies including GnRH (gonadotropin-releasing hormone) modulators, androgen receptor antagonists, selective estrogen receptor modulators, and aromatase inhibitors are associated with cardiotoxicity, including arrhythmia and venous thromboembolism. However, sex-based differences have not yet been elucidated. Evaluation of sex differences in cardiotoxicity related to immune therapy is limited, in part, due to low participation of females in relevant clinical trials. However, some studies suggest that females are at increased risk of immune checkpoint inhibitor myocarditis, although this has not been consistently demonstrated. For each of the aforementioned cancer therapies, we consider sex-based differences according to cardiotoxicity management. We identify knowledge gaps to guide future mechanistic and prospective clinical studies. Furthering our understanding of sex-based differences in cancer therapy cardiotoxicity can advance the development of targeted preventive and therapeutic cardioprotective strategies.

Characteristics and Spectrum of Cardiotoxicity Induced by Various Antipsychotics: A Real-World Study From 2015 to 2020 Based on FAERS

Objective: This study aimed to investigate the characteristics and spectrum of cardiotoxicity induced by various antipsychotics based on the United States Food and Drug Administration (FDA) Adverse Event Reporting System (FAERS) database.

Methods: Data of the FAERS database from the first quarter of 2015 to the fourth quarter of 2020 were downloaded for disproportionality analysis. The significant signal was evaluated by reporting odds ratios and information components with statistical shrinkage transformation.

Results: A total of 2,361,487 records were extracted for disproportionality analysis. Among the 10 antipsychotics, clozapine and amisulpride performed strong cardiotoxicity. Cardiomyopathy, cardiac arrhythmia, and Torsade de pointes/QT prolongation were the common cardiac adverse event induced by antipsychotics. Different characteristics of the spectrum of cardiotoxicity in various APs were discovered after further data mining. Moreover, evidence of the association between antipsychotics and eosinophilic myocarditis, peripartum cardiomyopathy was provided in this study.

Conclusion: Antipsychotics presented cardiotoxicity in different degrees, and more cardiac examinations should be monitored in patients with antipsychotics.

Abiraterone-induced refractory hypokalaemia and torsades de pointes in a patient with metastatic castration-resistant prostate carcinoma: a case report

Background

Abiraterone, an androgen deprivation therapy, has been used in the treatment of metastatic castration-resistant prostate cancer (mCRPC). It has been associated with increased risks of hypokalaemia and cardiac disorders. We report a case of torsades de pointes (TdP) associated with abiraterone use and refractory hypokalaemia in a man with mCRPC.

Case summary

A 78-year-old man with mCRPC presented to the emergency room for generalized weakness. Laboratory results revealed a potassium level of 2.2 mmol/L (3.5–5.0), magnesium level of 2.4 mg/dL (1.6–2.5), and normal kidney and hepatic functions. Initial electrocardiogram showed atrial fibrillation with rapid ventricular rate of 106 b.p.m., frequent premature ventricular contractions, and a QTc of 634 ms. The patient had multiple episodes of TdP, became pulseless and underwent advanced cardiac life support, including defibrillation. Despite a total of 220 mEq of intravenous potassium chloride, his potassium level only improved to 2.8 mmol/L. He received spironolactone and amiloride to promote urinary potassium reabsorption in addition to hydrocortisone, in an effort to reduce abiraterone’s effect on increasing mineralocorticoid synthesis.

Discussion

Abiraterone has been widely used in mCRPC since its approval by the Food and Drug Adminstration in 2011. Regulatory guidelines and standardized close QTc and electrolyte monitoring in patients may help prevent fatal arrhythmias associated with abiraterone.

Anticancer drug-induced life-threatening ventricular arrhythmias: a World Health Organization pharmacovigilance study

AIMS

With the explosion of anticancer drugs, an emerging concern is the risk for drug-induced sudden death (SD) via ventricular arrhythmias (VA).

METHODS AND RESULTS

We used the international pharmacovigilance database VigiBase (n = 18 441 659 reports) to compare drug-induced long QT (diLQT, n = 18 123) and VA (n = 29 193) including torsade de pointes (TdP, n = 8163) reporting for 663 anticancer drugs vs. all other drugs until 01/01/2019. The analysis used the 95% lower-end credibility interval of the information component (IC025), an indicator for disproportionate Bayesian reporting; significant when IC025 >0. There were 2301 reports (13.8% fatal) for 40 anticancer drugs significantly associated with diLQT (with 27 also associated with VA or SD) and 9 drugs associated with VA without diLQT. Half of these (46.9%, 23/49) were associated with SD. Most (41%, 20/49) were kinase inhibitors, 8% (4/49) were hormonal therapies, 6% (3/49) were immunotherapies, 24% (12/49) were cytotoxics, and 20% (10/49) were miscellaneous. In VigiBase, reports of diLQT, TdP, or VA increased from 580 in the period 1967-83 to 15 070 in 2014-18 with the proportion related to anticancer drugs increasing from 0.9% (5/580) to 14.0% (2115/15 070) (P < 0.0001). Concordance between these VigiBase signals and data concerning diLQT and VA/TdP identified in CredibleMeds or US Food and Drug Administration (FDA) labels was moderate (κ = 0.47 and 0.40, P < 0.0001). Twenty-three drugs represent new signals, while 24 flagged by CredibleMeds or FDA had no signal in VigiBase. A three-level SD risk stratification relying on isolated long QT (low risk), associated with VA without SD (moderate risk), and VA with SD (high risk) is proposed.

CONCLUSION

This list of liable anticancer drugs may prove useful for physicians and regulatory authorities to re-evaluate cardiac monitoring requirements.

CLINICAL TRIAL REGISTRATION

NCT03530215.

An open label randomized controlled trial of tamoxifen combined with amphotericin B and fluconazole for cryptococcal meningitis

Background

Cryptococcal meningitis has high mortality. Flucytosine is a key treatment but is expensive and rarely available. The anticancer agent tamoxifen has synergistic anti-cryptococcal activity with amphotericin in vitro. It is off-patent, cheap, and widely available. We performed a trial to determine its therapeutic potential.

Methods

Open label randomized controlled trial. Participants received standard care - amphotericin combined with fluconazole for the first 2 weeks - or standard care plus tamoxifen 300 mg/day. The primary end point was Early Fungicidal Activity (EFA) - the rate of yeast clearance from cerebrospinal fluid (CSF). Trial registration https://clinicaltrials.gov/ct2/show/NCT03112031.

Results

Fifty patients were enrolled (median age 34 years, 35 male). Tamoxifen had no effect on EFA (-0.48log10 colony-forming units/mL/CSF control arm versus -0.49 tamoxifen arm, difference -0.005log10CFU/ml/day, 95% CI: -0.16, 0.15, p=0.95). Tamoxifen caused QTc prolongation.

Conclusions

High-dose tamoxifen does not increase the clearance rate of Cryptococcus from CSF. Novel, affordable therapies are needed.

Funding

The trial was funded through the Wellcome Trust Asia Programme Vietnam Core Grant 106680 and a Wellcome Trust Intermediate Fellowship to JND grant number WT097147MA.

When Manual Analysis of 12-Lead ECG Holter Plays a Critical Role in Discovering Unknown Patterns of Increased Arrhythmogenic Risk: A Case Report of a Patient Treated with Tamoxifen and Subsequent Pneumonia in COVID-19

Several medicines, including cancer therapies, are known to alter the electrophysiological function of ventricular myocytes resulting in abnormal prolongation and dispersion of ventricular repolarization (quantified by multi-lead QTc measurement). This effect could be amplified by other concomitant factors (e.g., combination with other drugs affecting the QT, and/or electrolyte abnormalities, such as especially hypokalemia, hypomagnesaemia, and hypocalcemia). Usually, this condition results in higher risk of torsade de point and other life-threatening arrhythmias, related to unrecognized unpaired cardiac ventricular repolarization reserve (VRR). Being VRR a dynamic phenomenon, QT prolongation might often not be identified during the 10-s standard 12-lead ECG recording at rest, leaving the patient at increased risk for life-threatening event. We report the case of a 49-year woman, undergoing tamoxifen therapy for breast cancer, which alteration of ventricular repolarization reserve, persisting also after correction of concomitant recurrent hypokalemia, was evidenced only after manual measurements of the corrected QT (QTc) interval from selected intervals of the 12-lead ECG Holter monitoring. This otherwise missed finding was fundamental to drive the discontinuation of tamoxifen, shifting to another "safer" therapeutic option, and to avoid the use of potentially arrhythmogenic antibiotics when treating a bilateral pneumonia in recent COVID-19.

The Impact of Testosterone on the QT Interval: A Systematic Review

Humans and mammals have sex-specific differences in cardiac electrophysiology, linked to the action of sex hormones in the cardiac muscle. These hormones can upregulate or downregulate the expression of ionic channels modulating the cardiac cycle through genomic and non-genomic interactions. Systematic search in PubMed, Medline and EMBASE including keywords pertaining to testosterone and QT interval. Included experimental studies and observation studies and case reports presenting the results of testosterone administration, excess or deficiency in humans and animals. Testosterone has been shown to shorten the action potential duration, by enhancing the expression of K⁺ channels and downregulating I_CaL increasing the repolarization reserve of the cardiac muscle. This effect has been observed in both genders and animals. Testosterone deficient states can promote arrhythmogenesis. The evidence in this paper may be used to guide clinical considerations, such as increased clinical surveillance of patients in testosterone deficient states using ECG.

Cardiovascular toxicity of breast cancer treatment: an update

Novel chemotherapeutic agents have marked a new era in oncology during the past decade, prolonging significantly the overall survival of breast cancer patients. Nevertheless, contemporary antineoplastic treatments can frequently cause adverse cardiovascular side effects. Common manifestations of chemotherapy-induced cardiotoxicity include cardiomyopathy, ischemia, conduction disturbances, hypertension and thromboembolic events, while the type of the treatment regimen administered crucially determines clinical outcome. The aim of this literature review is to analyze the incidence and the underlying mechanisms of cardiovascular toxicity caused by agents approved for breast cancer, as well as to describe ways of monitoring and treating the cardiotoxic effects in breast cancer patients. Moreover, our work intends to provide an easy-to-grasp synopsis of recent and clinically meaningful advances in the field.

Flavonoids and hERG channels: Friends or foes?

The cardiac action potential is regulated by several ion channels. Drugs capable to block these channels, in particular the human ether-à-go-go-related gene (hERG) channel, also known as K_V11.1 channel, may lead to a potentially lethal ventricular tachyarrhythmia called "Torsades de Pointes". Thus, evaluation of the hERG channel off-target activity of novel chemical entities is nowadays required to safeguard patients as well as to avoid attrition in drug development. Flavonoids, a large class of natural compounds abundantly present in food, beverages, herbal medicines, and dietary food supplements, generally escape this assessment, though consumed in consistent amounts. Continuously growing evidence indicates that these compounds may interact with the hERG channel and block it. The present review, by examining numerous studies, summarizes the state-of-the-art in this field, describing the most significant examples of direct and indirect inhibition of the hERG channel current operated by flavonoids. A description of the molecular interactions between a few of these natural molecules and the Rattus norvegicus channel protein, achieved by an in silico approach, is also presented.

Sexual Dimorphisms, Anti-Hormonal Therapy and Cardiac Arrhythmias

Significant variations from the normal QT interval range of 350 to 450 milliseconds (ms) in men and 360 to 460 ms in women increase the risk for ventricular arrhythmias. This difference in the QT interval between men and women has led to the understanding of the influence of sex hormones on the role of gender-specific channelopathies and development of ventricular arrhythmias. The QT interval, which represents the duration of ventricular repolarization of the heart, can be affected by androgen levels, resulting in a sex-specific predilection for acquired and inherited channelopathies such as acquired long QT syndrome in women and Brugada syndrome and early repolarization syndrome in men. Manipulation of the homeostasis of these sex hormones as either hormonal therapy for certain cancers, recreational therapy or family planning and in transgender treatment has also been shown to affect QT interval duration and increase the risk for ventricular arrhythmias. In this review, we highlight the effects of endogenous and exogenous sex hormones in the physiological and pathological states on QTc variation and predisposition to gender-specific pro-arrhythmias.

Electrocardiographic Characteristics of Breast Cancer Patients Treated with Chemotherapy

Introduction

Patients receiving chemotherapy for breast cancer may be at risk of developing cardiac dysfunction and electrophysiological abnormalities. The aim of this study is to evaluate alterations in electrocardiographic (ECG) parameters in breast cancer patients receiving chemotherapy.

Materials and Methods

This was a prospective single-center cohort study conducted in the Fourth Hospital of Hebei Medical University, China. Participants with breast cancer referred for chemotherapy from May 1, 2019, to October 1, 2019, were invited to participate in the study. Standard 12-lead ECG and echocardiography were performed at baseline or before chemotherapy (prechemotherapy) (T0), after 1 cycle (T1), after 3 cycles (T2), and at the end of chemotherapy (T3).

Results

A total of 64 patients with diagnosed breast cancer undergoing chemotherapy were included. Echocardiographic parameters showed no significant variation during the entire procedure (all P > 0.05). The incidence of abnormal ECG increased from 43.75% at baseline to 65.63% at the end of chemotherapy, of which only the prevalence of fragmented QRS (fQRS) was significantly increased after the drug regimen (26.56% to 53.13%). At the end of the treatment, heart rate, P-wave dispersion, corrected QT interval, T-peak to T-end, RR, SV1, RV5, Sokolow–Lyon index (SLI), and index of cardioelectrophysiological balance deteriorated markedly (all P < 0.05). The area under the curve for SLI and QT dispersion (QTd) derived by ECG was 0.710 and 0.606, respectively. The cutoff value with 2.12 of SLI by ECG had a sensitivity of 67.2% and specificity of 71.9% for differentiating patients after therapy from baselines. The cutoff value with 0.55 of QTd had a sensitivity of 60.9% and specificity of 60.9%.

Conclusions

The current study demonstrated that ECGs can be used to detect electrophysiological abnormalities in breast cancer patients receiving chemotherapy. ECG changes can reflect subclinical cardiac dysfunction before the echocardiographic abnormalities.

Ibrutinib-Mediated Atrial Fibrillation Attributable to Inhibition of C-Terminal Src Kinase

BACKGROUND

Ibrutinib is a Bruton tyrosine kinase inhibitor with remarkable efficacy against B-cell cancers. Ibrutinib also increases the risk of atrial fibrillation (AF), which remains poorly understood.

METHODS

We performed electrophysiology studies on mice treated with ibrutinib to assess inducibility of AF. Chemoproteomic analysis of cardiac lysates identified candidate ibrutinib targets, which were further evaluated in genetic mouse models and additional pharmacological experiments. The pharmacovigilance database, VigiBase, was queried to determine whether drug inhibition of an identified candidate kinase was associated with increased reporting of AF.

RESULTS

We demonstrate that treatment of mice with ibrutinib for 4 weeks results in inducible AF, left atrial enlargement, myocardial fibrosis, and inflammation. This effect was reproduced in mice lacking Bruton tyrosine kinase, but not in mice treated with 4 weeks of acalabrutinib, a more specific Bruton tyrosine kinase inhibitor, demonstrating that AF is an off-target side effect. Chemoproteomic profiling identified a short list of candidate kinases that was narrowed by additional experimentation leaving CSK (C-terminal Src kinase) as the strongest candidate for ibrutinib-induced AF. Cardiac-specific Csk knockout in mice led to increased AF, left atrial enlargement, fibrosis, and inflammation, phenocopying ibrutinib treatment. Disproportionality analyses in VigiBase confirmed increased reporting of AF associated with kinase inhibitors blocking Csk versus non-Csk inhibitors, with a reporting odds ratio of 8.0 (95% CI, 7.3-8.7; P<0.0001).

CONCLUSIONS

These data identify Csk inhibition as the mechanism through which ibrutinib leads to AF. Registration: URL: https://ww.clinicaltrials.gov; Unique identifier: NCT03530215.

Cardiotoxicity Associated with Gemcitabine: Literature Review and a Pharmacovigilance Study

BACKGROUND

Gemcitabine is a nucleoside analog, widely used either alone or in combination, for the treatment of multiple cancers. However, gemcitabine may also be associated with cardiovascular adverse-drug-reactions (CV-ADR).

METHODS

First, we searched for all cases of cardiotoxicity associated with gemcitabine, published in MEDLINE on 30 May 2019. Then, we used VigiBase, the World Health Organization's global database of individual case safety reports, to compare CV-ADR reporting associated with gemcitabine against the full database between inception and 1 April 2019. We used the information component (IC), an indicator value for disproportionate Bayesian reporting. A positive lower end of the 95% credibility interval for the IC (IC₀₂₅) ≥ 0, is deemed significant.

RESULTS

In VigiBase, 46,898 reports were associated with gemcitabine on a total of 18,908,940 in the full database. Gemcitabine was associated with higher reporting for myocardial ischemia (MI, n: 119), pericardial diseases (n: 164), supraventricular arrhythmias (SVA, n: 308) and heart failure (HF, n: 484) versus full database with IC₀₂₅ ranging between 0.40 and 2.81. CV-ADR were associated with cardiovascular death in up to 17% of cases.

CONCLUSION

Treatment with gemcitabine is associated with potentially lethal CV-ADRs, including MI, pericardial diseases, SVA and HF. These events should be considered in patient care and clinical trial design.

Immune checkpoint inhibitor-induced myositis, the earliest and most lethal complication among rheumatic and musculoskeletal toxicities

BACKGROUND

In addition to restoring anti-tumor immune responses, immune checkpoint inhibitors (ICI) may also induce immune-related adverse events (irAE) that can affect any organ. We aim to determine the spectrum, timing, clinical features, and fatalities of rheumatic and musculoskeletal immune-related adverse events (RMS-irAE) associated with ICI.

PATIENTS METHODS

We performed an observational, retrospective, pharmacovigilance study using the World Health Organization international pharmacovigilance database, VigiBase, from inception to January 2019. RMS-irAE reporting rate on ICI versus full database was performed using disproportionality analysis with computation of reporting-odds-ratios (ROR) and a Bayesian disproportional estimate (information component, IC). IC₀₂₅ (lower end of the IC 95% credibility interval) >0 is deemed significant.

RESULTS

We identified 1288 RMS-irAE significantly associated with ICI: polymyalgia rheumatica (n = 76, ROR = 14.6 [11.6-18.4], IC₀₂₅ = 3.34), sarcoidosis (n = 94; ROR = 9.6 [7.9-11.9]; IC₀₂₅ = 2.85), Sjogren's syndrome (n = 49; ROR = 6.9 [5.2-9.2]; IC₀₂₅ = 2.24), myositis (n = 465; ROR = 4.9 [4.5-5.4]; IC₀₂₅ = 2.12), arthritis (n = 606; ROR = 1.4 [1.3-1.5]; IC₀₂₅ = 0.34) and scleroderma (n = 17; ROR = 2.0 [1.2-3.2]; IC₀₂₅ = 0.17). Arthritis, myositis, and Sjogren's syndrome were over-reported in patients treated with ICI combination versus those treated with ICI monotherapy (ROR = 1.6-2.9, p < .05) and more frequently reported on anti-PD1/PDL1 monotherapy vs. anti-CTLA4 monotherapy (2.1-4.4, p < .05). Median time to onset occurred early for myositis (31 days [19.2-57.8]) and was the most delayed for scleroderma (395 days [323.8-457.2], p < .0001). The fatality rate for RMS-irAE ranged from 24% for myositis (n = 106/441) (up to 56.7% with concurrent myocarditis) to [0-6.7%] for other RMS-irAE (p < .0001).

CONCLUSIONS

Clinicians should be aware of the spectrum of RMS-irAE. Myositis can be particularly life-threatening, particularly when associated with myocarditis.

Cardiovascular Toxicities Associated With Ibrutinib

BACKGROUND

Ibrutinib has revolutionized treatment for several B-cell malignancies. However, a recent clinical trial where ibrutinib was used in a front-line setting showed increased mortality during treatment compared with conventional chemotherapy. Cardiovascular toxicities were suspected as the culprit but not directly assessed in the study.

OBJECTIVES

The purpose of this study was to identify and characterize cardiovascular adverse drug reactions (CV-ADR) associated with ibrutinib.

METHODS

This study utilized VigiBase (International pharmacovigilance database) and performed a disproportionality analysis using reporting odds ratios (ROR) and information component (IC) to determine whether CV-ADR and CV-ADR deaths were associated with ibrutinib. IC compares observed and expected values to find associations between drugs and adverse drug reactions using disproportionate Bayesian-reporting; IC₀₂₅ (lower end of the IC 95% credibility interval) >0 is significant.

RESULTS

This study identified 303 ibrutinib-associated cardiovascular deaths. Ibrutinib was associated with higher reporting of supraventricular arrhythmias (SVAs) (ROR: 23.1; 95% confidence interval: 21.6 to 24.7; p < 0.0001; IC₀₂₅: 3.97), central nervous system (CNS) hemorrhagic events (ROR: 3.7; 95% confidence interval: 3.4 to 4.1; p < 0.0001; IC₀₂₅: 1.63), heart failure (ROR: 3.5; 95% confidence interval: 3.1 to 3.8; p < 0.0001; IC₀₂₅: 1.46), ventricular arrhythmias (ROR: 4.7; 95% confidence interval: 3.7 to 5.9; p < 0.0001; IC₀₂₅: 0.96), conduction disorders (ROR: 3.5; 95% confidence interval: 2.7 to 4.6; p < 0.0001; IC₀₂₅: 0.76), CNS ischemic events (ROR: 2.2; 95% confidence interval: 2.0 to 2.5; p < 0.0001; IC₀₂₅: 0.73), and hypertension (ROR: 1.7; 95% confidence interval: 1.5 to 1.9; p < 0.0001; IC₀₂₅: 0.4). CV-ADR often occurred early after ibrutinib administration. Importantly, CV-ADR were associated with fatalities that ranged from ∼10% (SVAs and ventricular arrhythmias) to ∼20% (CNS events, heart failure, and conduction disorders). Ibrutinib-associated SVA portends poor prognosis when CNS events occur concomitantly, with 28.8% deaths (15 of 52 cases).

CONCLUSIONS

Severe and occasionally fatal cardiac events occur in patients exposed to ibrutinib. These events should be considered in patient care and in clinical trial designs. (Evaluation of Reporting of Cardio-vascular Adverse Events With Antineoplastic and Immunomodulating Agents [EROCA]; NCT03530215).

Cardiac arrhythmia considerations of hormone cancer therapies

Breast and prostate cancers are among the most prevalent cancers worldwide. Oestradiol and progesterone are major drivers for breast cancer proliferation, and androgens for prostate cancer. Endocrine therapies are drugs that interfere with hormone-activated pathways to slow cancer progression. Multiple new breakthrough drugs improving overall survival have recently been developed within this class. As the use of these latter drugs grows, incidence of cardiac arrhythmias has emerged as an unappreciated complication. These changes are not surprising given that sex hormones alter ventricular repolarization. Testosterone shortens action potential duration and QT interval duration, while oestradiol has an opposite effect. In patients with breast cancer, selective oestrogen receptor modulators are associated with more reports for long QT and torsade de pointes (TdP) than aromatase inhibitors, likely through an oestradiol-like effect on the heart. Cyclin-dependent kinase 4/6 inhibitors, a new class of anticancer drugs used in combination with endocrine therapies in hormone receptor positive breast cancer, are also variably associated with drug-induced long QT, particularly with ribociclib. In prostate cancer, androgen deprivation therapy is associated with long QT and TdP, and possibly atrial fibrillation for abiraterone. In this review, we have summarized the clinical and preclinical data focusing on cardiac arrhythmia considerations of hormone cancer therapies.

Thromboembolic, cardiovascular and overall mortality risks of aromatase inhibitors, compared with tamoxifen treatment: an outpatient-register-based retrospective cohort study

Background:

Tamoxifen (TAM) and aromatase inhibitor (AI) therapies have been associated with increased risk of thromboembolic and cardiovascular events, respectively, in addition to other side effects. This study analysed the risk of these events and the overall survival (OS) benefit in breast cancer patients treated with AI, compared with TAM-treated patients, in a large population-based cohort.

Methods:

This observational cohort study included women diagnosed with breast cancer and treated with TAM or AI. Data were extracted from primary care records in a population database (SIDIAP, System for the Development of Research in Primary Care). Incidence rates of study outcomes are reported. Survival analyses included Kaplan–Meier estimation and Cox proportional hazards models. Sensitivity analysis was carried out, using Fine and Gray models to account for competing risk of death. Confounding was minimized using propensity score adjustment and inverse probability weighting (IPW) adjustment.

Results:

Data from 3082 postmenopausal women treated with TAM, and 18,455 treated with AI, were available. Adjusted hazard ratios (HRs) [95% confidence interval (CI)] for AI users, compared with TAM group, were 0.93 (95%CI 0.69–1.26) for thromboembolic events (TEEs); 1.13 (95%CI 0.79–1.63) for cardiovascular events, and 0.76 (95%CI 0.70–0.82) for mortality. Additional analyses using competing risk analysis had similar results, while IPW adjustment showed a potential risk of pulmonary embolism (PE) [2.26 (95%CI 1.02–4.97)] in AI-treated patients.

Conclusions:

AI users had >20% lower all-cause mortality compared with TAM users, without increasing risk to experience cardiovascular and TEEs. This would locate AI therapy on the first line in clinical practice. Thus, AI might be the most preferable option in adjuvant hormonal therapy choice.

The Risk of QTc-Interval Prolongation in Breast Cancer Patients Treated with Tamoxifen in Combination with Serotonin Reuptake Inhibitors

PURPOSE

Antidepressants like the serotonin reuptake inhibitors (SRIs) are often used concomitantly with tamoxifen (e.g. for treatment of depression). This may lead to an additional prolongation of the QTc-interval, with an increased risk of cardiac side effects. Therefore we investigated whether there is a drug-drug interaction between tamoxifen and SRIs resulting in a prolonged QTc-interval.

METHODS

Electrocardiograms (ECGs) of 100 patients were collected at steady state tamoxifen treatment, with or without concomitant SRI co-medication. QTc-interval was manually measured and calculated using the Fridericia formula. Primary outcome was difference in QTc-interval between tamoxifen monotherapy and tamoxifen concomitantly with an SRI.

RESULTS

The mean QTc-interval was 12.4 ms longer when tamoxifen was given concomitantly with an SRI (95% CI:1.8-23.1 ms; P = 0.023). Prolongation of the QTc-interval was particularly pronounced for paroxetine (17.2 ms; 95%CI:1.4-33.0 ms; P = 0.04), escitalopram (12.5 ms; 95%CI:4.4-20.6 ms; P < 0.01) and citalopram (20.7 ms; 95%CI:0.7-40.7 ms; P = 0.047), where other agents like venlafaxine did not seem to prolong the QTc-interval. None of the patients had a QTc-interval of >500 ms.

CONCLUSIONS

Concomitant use of tamoxifen and SRIs resulted in a significantly higher mean QTc-interval, which was especially the case for paroxetine, escitalopram and citalopram. When concomitant administration with an SRI is warranted venlafaxine is preferred.

Association of Oral Contraceptives With Drug-Induced QT Interval Prolongation in Healthy Nonmenopausal Women

Importance

Women are at higher risk of drug-induced torsade de pointes (TdP) than men. Androgens are protective. Influence of oral contraception on drug-induced TdP and QT prolongation is controversial.

Objective

To determine if the extent of sotalol-induced corrected QT (QTc) prolongation and specific T-wave morphological changes, which are biomarkers for the risk of drug-induced TdP, differ in patients according to the androgenic activity of the type of oral contraceptive (OCs) they take compared with patients who took no pills.

Design, Setting, and Participants

A cohort of 498 healthy, nonmenopausal women received 80 mg of oral sotalol, a drug with known risk of drug-induced TdP, during this study in a clinical investigation center. The participants also took either no oral contraception or received OCs with different types of progestin: levonorgestrel (which has high androgenic potency), desogestrel or gestodene (which has intermediate androgenic potency), or drospirenone (which has antiandrogenic properties). Women were enrolled from February 2008 to February 2012, and data analysis took place from September 2014 to May 2018.

Main Outcomes and Measures

Electrocardiographic changes 3 hours after sotalol administration.

Results

A total of 137 women received levonorgestrel, 41 received desogestrel, 51 received gestodene, and 62 received drospirenone; another 207 received no OCs. Baseline QTc duration, plasma sotalol levels, and potassium levels did not significantly differ among groups. However, 3 hours after sotalol exposure, QTc prolongation was greater in women taking drospirenone (mean [SD] increase, 31.2 [12.6] milliseconds from baseline) than in women taking no OCs (mean [SD] increase, 24.6 [12.5] milliseconds; P = .005) or those taking levonorgestrel (mean [SD] increase, 24.2 [13.7] milliseconds; P = .005). The frequency of sotalol-induced T-wave alteration was higher in women taking drospirenone (n = 13 of 61 [21.0%]) than those taking levonorgestrel (n = 20 of 137 [14.6%]) or women taking no OCs (n = 24 of 207 [11.6%]; P = .01). Disproportionality analysis using the European pharmacovigilance database showed a higher reporting rate of OC-induced prolonged QT and ventricular arrhythmias in women taking drospirenone than levonorgestrel (drug-induced long QT syndrome: reporting odds ratio [ROR], 6.2 [95% CI, 1.3-30.8]; P = .01; ventricular arrhythmia: ROR, 3.3 [95% CI, 1.7-6.3]; P < .001).

Conclusions and Relevance

Contraceptive pills are associated with variable drug-induced alterations of ventricular repolarization in healthy nonmenopausal women. Drospirenone, an antiandrogenic pill, was associated with increased sotalol-induced QTc prolongation, although absolute QTc prolongation was modest. This finding was supported by the European pharmacovigilance database, which showed a higher reporting rate of suspected OC-induced ventricular arrhythmias on drospirenone compared with levonorgestrel. More data are required on whether antiandrogenic OCs lead to clinically significant adverse events in patients taking QTc-prolonging drugs.

Androgenic Effects on Ventricular Repolarization: A Translational Study From the International Pharmacovigilance Database to iPSC-Cardiomyocytes

BACKGROUND

Male hypogonadism, arising from a range of etiologies including androgen-deprivation therapies (ADTs), has been reported as a risk factor for acquired long-QT syndrome (aLQTS) and torsades de pointes (TdP). A full description of the clinical features of aLQTS associated with ADT and of underlying mechanisms is lacking.

METHODS

We searched the international pharmacovigilance database VigiBase for men (n=6 560 565 individual case safety reports) presenting with aLQTS, TdP, or sudden death associated with ADT. In cardiomyocytes derived from induced pluripotent stem cells from men, we studied electrophysiological effects of ADT and dihydrotestosterone.

RESULTS

Among subjects receiving ADT in VigiBase, we identified 184 cases of aLQTS (n=168) and/or TdP (n=68; 11% fatal), and 99 with sudden death. Of the 10 ADT drugs examined, 7 had a disproportional association (reporting odds ratio=1.4-4.7; P<0.05) with aLQTS, TdP, or sudden death. The minimum and median times to sudden death were 0.25 and 92 days, respectively. The androgen receptor antagonist enzalutamide was associated with more deaths (5430/31 896 [17%]; P<0.0001) than other ADT used for prostate cancer (4208/52 089 [8.1%]). In induced pluripotent stem cells, acute and chronic enzalutamide (25 µM) significantly prolonged action potential durations (action potential duration at 90% when paced at 0.5 Hz; 429.7±27.1 (control) versus 982.4±33.2 (acute, P<0.001) and 1062.3±28.9 ms (chronic; P<0.001), and generated afterdepolarizations and/or triggered activity in drug-treated cells (11/20 acutely and 8/15 chronically). Enzalutamide acutely and chronically inhibited delayed rectifier potassium current, and chronically enhanced late sodium current. Dihydrotestosterone (30 nM) reversed enzalutamide electrophysiological effects on induced pluripotent stem cells.

CONCLUSIONS

QT prolongation and TdP are a risk in men receiving enzalutamide and other ADTs.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov. Unique identifier: NCT03193138.

Neurologic toxicity associated with immune checkpoint inhibitors: a pharmacovigilance study

BACKGROUND

Immune checkpoint inhibitors (ICI) produce durable antitumor responses but provoke autoimmune toxicities, including uncommon but potentially devastating neurologic toxicities. The clinical features, including the spectrum, timing, and outcomes, of ICI-induced neurologic toxicities are not well characterized.

METHODS

We performed disproportionality analysis using Vigibase, the World Health Organization pharmacovigilance database, comparing neurologic adverse event (AE) reporting in patients receiving ICIs vs. the full database. Neurologic AEs were classified by group queries using Medical Dictionary for Regulatory Activities, between database inception to September 28, 2018. Associations between ICIs and neurologic AEs were assessed using reporting odds ratios (ROR) and information component (IC). IC compares observed and expected values to find associations between drugs and AEs using disproportionate Bayesian reporting; IC025 (lower end of the IC 95% credibility interval) > 0 is considered statistically significant.

RESULTS

Among the full database, 18,518,994 AEs were reported, including 48,653 with ICIs. ICIs were associated with higher incidence of myasthenia gravis (0.47% of ICI reports vs. 0.04% of the full database, ROR 16.5 [95% CI 14.5-18.9]; IC025 3.31), encephalitis (0.51% vs. 0.05%, ROR 10.4 [95% CI 9.2-11.8]; IC025 3.15), peripheral neuropathy (1.16% vs. 0.67%, IC025 0.68), and meningitis (0.15% vs. 0.06%, ROR 3.1 [95% CI 2.5-3.9]; IC025 1.01). Myasthenia gravis and encephalitis were associated with anti-PD-1 whereas other neurologic AEs were associated with anti-CTLA-4. Myasthenia gravis was characterized by high fatality rates (~ 20%), early onset (median 29 days), and frequent concurrent myocarditis and myositis; whereas other neurologic AEs had lower fatality rates (6-12%), later onset (median 61-80 days), and were non-overlapping.

CONCLUSIONS

ICIs produce a spectrum of distinct classes of neurologic AEs that can cause significant morbidity and mortality and tend to occur early and with class-specific associations.

Risk Factors of QTc Prolongation in Women With Hormone Receptor‒positive/Human Epidermal Growth Factor Receptor 2‒negative Metastatic Breast Cancer: A Retrospective Analysis of Health Care Claims Data

PURPOSE

In addition to biomarker status, treatment selection for metastatic breast cancer (mBC) includes individual patient and clinical characteristics such as tumor burden, timing of disease recurrence, and comorbidities. Women with mBC may take medications that can increase the risk of drug-induced toxicities, including prolongation of cardiac repolarization (prolongation of QT interval). Corrected QT (QTc) prolongation, a toxicity associated with many cancer treatments, can lead to potentially life-threatening ventricular arrhythmias. As such, it is important to identify patients at risk for QTc prolongation due to comorbid conditions, concomitant medications, or electrolyte abnormalities. This real-world study estimated the proportion of women with hormone receptor‒positive (HR+)/human epidermal growth factor receptor 2‒negative (HER2‒) mBC who may be at risk of developing QTc prolongation. Results in the elderly are also included.

METHODS

This retrospective, cross-sectional cohort study used the Truven Health MarketScan and Optum Clinformatics administrative claims databases. Patients' medical and pharmacy data were evaluated to assess the risk of QTc prolongation. Prescription and medication administration claims were evaluated during the 7-day period before the index date (ie, first secondary neoplasm diagnosis). In addition, International Classification of Diseases, Ninth/Tenth Revision, Clinical Modification, codes were evaluated 12 months before the index date to describe congenital long QT syndrome, cardiac disease, and electrolyte abnormalities.

FINDINGS

A cohort of 24,340 women with HR+/HER2‒ mBC were identified, including 5059 women aged 65-74 years and 4851 aged ≥75 years. Based on an overall analysis of risk factors (congenital long QT syndrome, cardiovascular disease, electrolyte abnormalities, or concomitant medications), 29.5% of all patients, 33.2% of patients aged 65-74 years, and 40.5% of patients aged ≥75 years had risk factors for QTc prolongation.

IMPLICATIONS

This analysis of real-world data indicates that almost 1 in 3 women with HR+/HER2‒ mBC had congenital long QT syndrome, cardiovascular disease, and/or electrolyte abnormalities or received a concomitant medication that could increase the risk of developing QTc prolongation. The risk factors for congenital long QT syndrome, cardiovascular disease, or electrolyte abnormalities were more common in older patients. This analysis emphasizes the importance of individualized benefit/risk assessment during treatment decisions, especially when considering drugs with known or possible QTc prolongation risk.

Cardiolipotoxicity, Inflammation, and Arrhythmias: Role for Interleukin-6 Molecular Mechanisms

Fatty acid infiltration of the myocardium, acquired in metabolic disorders (obesity, type-2 diabetes, insulin resistance, and hyperglycemia) is critically associated with the development of lipotoxic cardiomyopathy. According to a recent Presidential Advisory from the American Heart Association published in 2017, the current average dietary intake of saturated free-fatty acid (SFFA) in the US is 11–12%, which is significantly above the recommended <10%. Increased levels of circulating SFFAs (or lipotoxicity) may represent an unappreciated link that underlies increased vulnerability to cardiac dysfunction. Thus, an important objective is to identify novel targets that will inform pharmacological and genetic interventions for cardiomyopathies acquired through excessive consumption of diets rich in SFFAs. However, the molecular mechanisms involved are poorly understood. The increasing epidemic of metabolic disorders strongly implies an undeniable and critical need to further investigate SFFA mechanisms. A rapidly emerging and promising target for modulation by lipotoxicity is cytokine secretion and activation of pro-inflammatory signaling pathways. This objective can be advanced through fundamental mechanisms of cardiac electrical remodeling. In this review, we discuss cardiac ion channel modulation by SFFAs. We further highlight the contribution of downstream signaling pathways involving toll-like receptors and pathological increases in pro-inflammatory cytokines. Our expectation is that if we understand pathological remodeling of major cardiac ion channels from a perspective of lipotoxicity and inflammation, we may be able to develop safer and more effective therapies that will be beneficial to patients.

Cardiovascular toxicities associated with immune checkpoint inhibitors: an observational, retrospective, pharmacovigilance study

BACKGROUND

Immune checkpoint inhibitors (ICIs) have substantially improved clinical outcomes in multiple cancer types and are increasingly being used in early disease settings and in combinations of different immunotherapies. However, ICIs can also cause severe or fatal immune-related adverse-events (irAEs). We aimed to identify and characterise cardiovascular irAEs that are significantly associated with ICIs.

METHODS

In this observational, retrospective, pharmacovigilance study, we used VigiBase, WHO's global database of individual case safety reports, to compare cardiovascular adverse event reporting in patients who received ICIs (ICI subgroup) with this reporting in the full database. This study included all cardiovascular irAEs classified by group queries according to the Medical Dictionary for Regulatory Activities, between inception on Nov 14, 1967, and Jan 2, 2018. We evaluated the association between ICIs and cardiovascular adverse events using the reporting odds ratio (ROR) and the information component (IC). IC is an indicator value for disproportionate Bayesian reporting that compares observed and expected values to find associations between drugs and adverse events. IC₀₂₅ is the lower end of the IC 95% credibility interval, and an IC₀₂₅ value of more than zero is deemed significant. This study is registered with ClinicalTrials.gov, number NCT03387540.

FINDINGS

We identified 31 321 adverse events reported in patients who received ICIs and 16 343 451 adverse events reported in patients treated with any drugs (full database) in VigiBase. Compared with the full database, ICI treatment was associated with higher reporting of myocarditis (5515 reports for the full database vs 122 for ICIs, ROR 11·21 [95% CI 9·36-13·43]; IC₀₂₅ 3·20), pericardial diseases (12 800 vs 95, 3·80 [3·08-4·62]; IC₀₂₅ 1·63), and vasculitis (33 289 vs 82, 1·56 [1·25-1·94]; IC₀₂₅ 0·03), including temporal arteritis (696 vs 18, 12·99 [8·12-20·77]; IC₀₂₅ 2·59) and polymyalgia rheumatica (1709 vs 16, 5·13 [3·13-8·40]; IC₀₂₅ 1·33). Pericardial diseases were reported more often in patients with lung cancer (49 [56%] of 87 patients), whereas myocarditis (42 [41%] of 103 patients) and vasculitis (42 [60%] of 70 patients) were more commonly reported in patients with melanoma (χ² test for overall subgroup comparison, p<0·0001). Vision was impaired in five (28%) of 18 patients with temporal arteritis. Cardiovascular irAEs were severe in the majority of cases (>80%), with death occurring in 61 (50%) of 122 myocarditis cases, 20 (21%) of 95 pericardial disease cases, and five (6%) of 82 vasculitis cases (χ² test for overall comparison between pericardial diseases, myocarditis, and vasculitis, p<0·0001).

INTERPRETATION

Treatment with ICIs can lead to severe and disabling inflammatory cardiovascular irAEs soon after commencement of therapy. In addition to life-threatening myocarditis, these toxicities include pericardial diseases and temporal arteritis with a risk of blindness. These events should be considered in patient care and in combination clinical trial designs (ie, combinations of different immunotherapies as well as immunotherapies and chemotherapy).

FUNDING

The Cancer Institut Thématique Multi-Organisme of the French National Alliance for Life and Health Sciences (AVIESAN) Plan Cancer 2014-2019; US National Cancer Institute, National Institutes of Health; the James C. Bradford Jr. Melanoma Fund; and the Melanoma Research Foundation.

Cardiovascular toxicities associated with immune checkpoint inhibitors: an observational, retrospective, pharmacovigilance study

BACKGROUND

Immune checkpoint inhibitors (ICIs) have substantially improved clinical outcomes in multiple cancer types and are increasingly being used in early disease settings and in combinations of different immunotherapies. However, ICIs can also cause severe or fatal immune-related adverse-events (irAEs). We aimed to identify and characterise cardiovascular irAEs that are significantly associated with ICIs.

METHODS

In this observational, retrospective, pharmacovigilance study, we used VigiBase, WHO's global database of individual case safety reports, to compare cardiovascular adverse event reporting in patients who received ICIs (ICI subgroup) with this reporting in the full database. This study included all cardiovascular irAEs classified by group queries according to the Medical Dictionary for Regulatory Activities, between inception on Nov 14, 1967, and Jan 2, 2018. We evaluated the association between ICIs and cardiovascular adverse events using the reporting odds ratio (ROR) and the information component (IC). IC is an indicator value for disproportionate Bayesian reporting that compares observed and expected values to find associations between drugs and adverse events. IC₀₂₅ is the lower end of the IC 95% credibility interval, and an IC₀₂₅ value of more than zero is deemed significant. This study is registered with ClinicalTrials.gov, number NCT03387540.

FINDINGS

We identified 31 321 adverse events reported in patients who received ICIs and 16 343 451 adverse events reported in patients treated with any drugs (full database) in VigiBase. Compared with the full database, ICI treatment was associated with higher reporting of myocarditis (5515 reports for the full database vs 122 for ICIs, ROR 11·21 [95% CI 9·36-13·43]; IC₀₂₅ 3·20), pericardial diseases (12 800 vs 95, 3·80 [3·08-4·62]; IC₀₂₅ 1·63), and vasculitis (33 289 vs 82, 1·56 [1·25-1·94]; IC₀₂₅ 0·03), including temporal arteritis (696 vs 18, 12·99 [8·12-20·77]; IC₀₂₅ 2·59) and polymyalgia rheumatica (1709 vs 16, 5·13 [3·13-8·40]; IC₀₂₅ 1·33). Pericardial diseases were reported more often in patients with lung cancer (49 [56%] of 87 patients), whereas myocarditis (42 [41%] of 103 patients) and vasculitis (42 [60%] of 70 patients) were more commonly reported in patients with melanoma (χ² test for overall subgroup comparison, p<0·0001). Vision was impaired in five (28%) of 18 patients with temporal arteritis. Cardiovascular irAEs were severe in the majority of cases (>80%), with death occurring in 61 (50%) of 122 myocarditis cases, 20 (21%) of 95 pericardial disease cases, and five (6%) of 82 vasculitis cases (χ² test for overall comparison between pericardial diseases, myocarditis, and vasculitis, p<0·0001).

INTERPRETATION

Treatment with ICIs can lead to severe and disabling inflammatory cardiovascular irAEs soon after commencement of therapy. In addition to life-threatening myocarditis, these toxicities include pericardial diseases and temporal arteritis with a risk of blindness. These events should be considered in patient care and in combination clinical trial designs (ie, combinations of different immunotherapies as well as immunotherapies and chemotherapy).

FUNDING

The Cancer Institut Thématique Multi-Organisme of the French National Alliance for Life and Health Sciences (AVIESAN) Plan Cancer 2014-2019; US National Cancer Institute, National Institutes of Health; the James C. Bradford Jr. Melanoma Fund; and the Melanoma Research Foundation.

Cardiovascular safety of oncologic agents: a double-edged sword even in the era of targeted therapies - Part 2

INTRODUCTION

Patients with cancer are subject to the cardiotoxic effects of cancer therapy. Improved cancer treatments lead to more cancer-survivors, who though are exposed to various forms of cardiovascular (CV) disease (CVD) as they age. Aging patients are at increased risk of developing both malignancy and CVD or they may have survived some form of CVD as a result of effective CV treatments. Furthermore, patients with CVD may develop cancer and require treatment (and vice versa), all contributing to increased morbidity and mortality. The prevalence of both malignancy and CVD will increase due to the trend toward a longer lifespan.

AREAS COVERED

In part 2 of this review, the discussion of the CV effects of specific oncology drugs is completed with inclusion of additional immunological agents, current hormonal and other agents. Early detection and monitoring of cardiotoxicity, use of biomarkers and other imaging and diagnostic methods and prevention and treatment options are also discussed.

EXPERT OPINION

As outlined in part 1 of this review, oncologists need to be aware of the CV adverse-effects of their treatments and make careful and expectant clinical decisions, especially in patients with preexisting CVD or CV risk factors. Similarly, cardiologists should consider a detailed previous history of treatment for malignant disease, including prior chemotherapy exposure, dose(s) received, and/or combined modality therapy with chest radiotherapy. Both specialists should collaborate in order to minimize the impact of these two ubiquitous diseases (cancer and CVD) and mitigate the adverse effects of treatment modalities.