QT interval prolongation among patients treated with angiogenesis inhibitors

The mechanism and treatment of targeted anti-tumour drugs induced cardiotoxicity

As the intensive anti-tumour therapy and combination of multiple anti-tumour drugs, cardiotoxicity events caused by anti-tumour drugs have also increased significantly, and the incidence of cardiotoxicity also increased with survival time. Different types of anti-tumour drugs could cause all kinds of cardiotoxicity which increase the difficulties in treatment and even live threatening. In this review, we concentrated in the targeted anti-tumour drugs such as human epidermal growth factor receptor-2 (HER2) inhibitors, tyrosine kinase inhibitors (TKIs), immune checkpoint inhibitors (ICIs), and proteasome inhibitors (Pls). The molecular mechanism of how these drugs induce cardiotoxicity is introduced which includes several signal pathways. These drugs induced cardiotoxicity involved heart failure, hypertension, atherosis and thrombosis, QT interval prolongation, and myocarditis. Some of the cardiotoxicity could be moderate and reversible but others could have happened severely.The aim of this review is to summarise the targeted anti-tumour drugs induced cardiotoxicity and treatment strategies.

Concentration QTc analysis of giredestrant: Overcoming QT/heart rate confounding in the presence of drug-induced heart rate changes

Concentration-QTc (C-QTc) analysis has become a common approach for evaluating proarrhythmic risk and delayed cardiac repolarization of oncology drug candidates. Significant heart rate (HR) change has been associated with certain classes of oncology drugs and can result in over- or underestimation of the true QT prolongation risk. Because oncology early clinical trials typically lack a placebo control arm or time-matched, treatment-free baseline electrocardiogram collection, significant HR change brings additional challenges to C-QTc analysis in the oncology setting. In this work, a spline-based correction method (QTcSPL) was explored to mitigate the impact of HR changes in giredestrant C-QTc analysis. Giredestrant is a selective estrogen receptor degrader being developed for the treatment of patients with estrogen receptor-positive (ER+) breast cancer. A dose-related HR decrease has been observed in patients under giredestrant treatment, with significant reductions (>10 bpm) observed at supratherapeutic doses. The QTcSPL method demonstrated superior functionality to reduce the correlation between QTc and HR as compared with the Fridericia correction (QTcF). The effect of giredestrant exposure on QTc was evaluated at the clinical dose of 30 mg and supratherapeutic dose of 100 mg based on a prespecified linear mixed effect model. The upper 90% confidence interval of ΔQTcSPL and ΔQTcF were below the 10 ms at both clinical and supratherapeutic exposures, suggesting giredestrant has a low risk of QT prolongation at clinically relevant concentrations. This work demonstrated the use case of QTcSPL to address HR confounding challenges in the context of oncology drug development for the first time.

Cytarabine-Induced Bradycardia: A Case Report

Cardiotoxicity is damage to the heart muscle, which affects its function. Chemotherapy is known to cause cardiotoxicity along with many other medications and etiologies. Many chemotherapeutic cocktails are known to be associated with cardiotoxicities, such as taxane and cisplatin. Patients might have arrhythmias, severe bradycardia, cardiomyopathy, and even cardiac arrest, so precautions are taken when such medications are started. This report presents a patient who developed severe symptomatic bradycardia after receiving idarubicin and cytarabine and was managed conservatively, along with a literature review of this entity.

Electrophysiological mechanisms of vandetanib-induced cardiotoxicity: Comparison of action potentials in rabbit Purkinje fibers and pluripotent stem cell-derived cardiomyocytes

Vandetanib, a multi-kinase inhibitor used for the treatment of various cancers, has been reported to induce several adverse cardiac effects. However, the underlying mechanisms of vandetanib-induced cardiotoxicity are unclear. This study aimed to investigate the mechanism of vandetanib-induced cardiotoxicity using intracellular electrophysiological recordings on human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs), rabbit Purkinje fibers, and HEK293 cells transiently expressing human ether-a-go-go-related gene (hERG; the rapidly activating delayed rectifier K⁺ channel, I_Kr), KCNQ1/KCNE1 (the slowly activating delayed rectifier K⁺ current, I_Ks), KCNJ2 (the inwardly rectifying K⁺ current, I_K1) or SCN5A (the inward Na⁺ current, I_Na). Purkinje fiber assays and ion channel studies showed that vandetanib at concentrations of 1 and 3 μM inhibited the hERG currents and prolonged the action potential duration. Alanine scanning and in silico hERG docking studies demonstrated that Y652 and F656 in the hERG S6 domain play critical roles in vandetanib binding. In hiPSC-CMs, vandetanib markedly reduced the maximum rate of depolarization during the AP upstroke. Ion channel studies revealed that hiPSC-CMs were more sensitive to inhibition of the I_Na by vandetanib than in a heterogeneously expressed HEK293 cell model, consistent with the changes in the AP parameters of hiPSC-CMs. The subclasses of Class I antiarrhythmic drugs inhibited I_Na currents in a dose-dependent manner in hiPSC-CMs and SCN5A-encoded HEK293 cells. The inhibitory potency of vandetanib for I_Na was much higher in hiPSC-CMs (IC₅₀: 2.72 μM) than in HEK293 cells (IC₅₀: 36.63 μM). These data suggest that AP and I_Na assays using hiPSC-CMs are useful electrophysiological models for prediction of drug-induced cardiotoxicity.

Cardiopulmonary fitness before and after neoadjuvant chemotherapy in patients with oesophagogastric cancer

Background

Neoadjuvant chemotherapy may have a detrimental impact on cardiorespiratory reserve. Determination of oxygen uptake at the anaerobic threshold by cardiopulmonary exercise testing (CPET) provides an objective measure of cardiorespiratory reserve. Anaerobic threshold can be used to predict perioperative risk. A low anaerobic threshold is associated with increased morbidity after oesophagogastrectomy. The aim of this study was to establish whether neoadjuvant chemotherapy has an adverse effect on fitness, and whether there is recovery of fitness before surgery for oesophageal and gastric adenocarcinoma.

Methods

CPET was completed before, immediately after (week 0), and at 2 and 4 weeks after neoadjuvant chemotherapy. The ventilatory anaerobic threshold and peak oxygen uptake (Vo2 peak) were used as objective, reproducible measures of cardiorespiratory reserve. Anaerobic threshold and Vo2 peak were compared before and after neoadjuvant chemotherapy, and at the three time intervals.

Results

Some 31 patients were recruited. The mean anaerobic threshold was lower following neoadjuvant treatment: 15·3 ml per kg per min before chemotherapy versus 11·8, 12·1 and 12·6 ml per kg per min at week 0, 2 and 4 respectively (P < 0·010). Measurements were also significantly different at each time point (P < 0·010). The same pattern was noted for Vo2 peak between values before chemotherapy (21·7 ml per kg per min) and at weeks 0, 2 and 4 (17·5, 18·6 and 19·3 ml per kg per min respectively) (P < 0·010). The reduction in anaerobic threshold and Vo2 peak did not improve during the time between completion of neoadjuvant chemotherapy and surgery.

Conclusion

There was a decrease in cardiorespiratory reserve immediately after neoadjuvant chemotherapy that was sustained up to the point of surgery at 4 weeks after chemotherapy.

Cardiovascular Complications of Cancer Therapy: Best Practices in Diagnosis, Prevention, and Management: Part 2

In this second part of a 2-part review, we will review cancer or cancer therapy-associated systemic and pulmonary hypertension, QT prolongation, arrhythmias, pericardial disease, and radiation-induced cardiotoxicity. This review is based on a MEDLINE search of published data, published clinical guidelines, and best practices in major cancer centers. Newly developed targeted therapy can exert off-target effects causing hypertension, thromboembolism, QT prolongation, and atrial fibrillation. Radiation therapy often accelerates atherosclerosis. Furthermore, radiation can damage the heart valves, the conduction system, and pericardium, which may take years to manifest clinically. Management of pericardial disease in cancer patients also posed clinical challenges. This review highlights the unique opportunity of caring for cancer patients with heart problems caused by cancer or cancer therapy. It is an invitation to action for cardiologists to become familiar with this emerging subspecialty.

A Prospective Study to Evaluate the Effect of Paclitaxel on Cardiac Ejection Fraction

BACKGROUND

The primary objective of the study was to evaluate the long-term changes in ejection fraction (EF) associated with paclitaxel infusion.

METHODS

50 patients were enrolled in this prospective study between 2011 and 2015. The study design included frequent follow-up visits to the clinic, EF evaluation at baseline, and regular EF assessment by echocardiography for 30 months after treatment.

RESULTS

The median baseline EF was 60% (95% confidence interval (CI) 50-80%). At 30 months, the median EF was 48% (95% CI 40-60%; p = 0.03). During the 30-month follow-up, 10 (20%) patients developed grade 1 and 2 cardiotoxicities; none developed grade 3 or 4 cardiotoxicities. Furthermore, paclitaxel cardiotoxicity increased among patients with high-risk features including associated diabetes mellitus, hypertension, prior radiotherapy to the chest wall, performance status of 2, and age > 60 years.

CONCLUSION

Paclitaxel has cardiotoxic effects. Careful monitoring of cardiac function during and after paclitaxel infusion is required in patients with high-risk features.

Mechanisms and Genetic Susceptibility of Chemotherapy-Induced Cardiotoxicity in Patients With Breast Cancer

BACKGROUND

Cardiotoxicity remains an important adverse reaction of chemotherapy used in the treatment of breast cancer, leading to increased morbidity and mortality.

DATA SOURCES

Anthracyclines, taxanes, and trastuzumab are the most commonly used cytotoxic drugs for the treatment of breast cancer. Cardiotoxicity may vary from asymptomatic forms to irreducible heart failure and death.

AREAS OF UNCERTAINTY

Susceptibility for the occurrence of chemotherapy-induced cardiotoxicity and treatment resistance is multifactorial, with interindividual variability, determined by the interaction between genetic and phenotypic factors. Implementation of pharmacogenomic findings into clinical practice might be useful, to predict cardiotoxicity and to allow appropriate therapeutic measures.

RESULTS AND CONCLUSIONS

This review will summarize the cellular mechanisms of chemotherapy-induced cardiotoxicity in breast cancer patients and will discuss the role of the genetic susceptibility for cardiac dysfunction.

Strategy for enhancing the therapeutic efficacy of histone deacetylase inhibitor dacinostat: the novel paradigm to tackle monotonous cancer chemoresistance

Histone deacetylases (HDACs) regulate gene expression by creating the closed state of chromatin via histone hypoacetylation. Histone acetylation deregulation caused by aberrant expression of classical HDACs leads to imprecise gene regulation culminating in various diseases including cancer. Histone deacetylase inhibitors (HDACi), the small-molecules modulating the biological function of HDACs have shown promising results in inducing cell cycle arrest, differentiation and apoptosis in tumour models. HDACi do not show desired cytotoxic effect when used in monotherapy due to triggering of various resistance mechanisms in cancer cells emphasizing the desperate need of novel strategies that can be used to overcome such challenges. The present article provides intricate details about the novel HDACi dacinostat (LAQ-824) against multiple myeloma and acute myeloid leukaemia. The distinct molecular mechanisms modulated by dacinostat in exerting cytotoxic effect against the defined malignancies have also been detailed. The article also explains the strategy that can be used to circumvent the conventional therapy resistant cases and for enhancing the therapeutic efficacy of dacinostat for effective anticancer therapy.

Prevention of Pazopanib-Induced Prolonged Cardiac Repolarization and Proarrhythmic Effects

Background

Pazopanib (PZP) may induce prolonged cardiac repolarization and proarrhythmic effects, similarly to other tyrosine kinase inhibitors.

Objectives

To demonstrate PZP-induced prolonged cardiac repolarization and proarrhythmic electrophysiological effects and to investigate possible preventive effects of metoprolol and diltiazem on ECG changes (prolonged QT) in an experimental rat model.

Methods

Twenty-four Sprague-Dawley adult male rats were randomly assigned to 4 groups (n = 6). The first group (normal group) received 4 mL of tap water and the other groups received 100 mg/kg of PZP (Votrient^® tablet) perorally, via orogastric tubes. After 3 hours, the following solutions were intraperitoneally administered to the animals: physiological saline solution (SP), to the normal group and to the second group (control-PZP+SP group); 1 mg/kg metoprolol (Beloc, Ampule, AstraZeneca), to the third group (PZP+metoprolol group); and 1mg/kg diltiazem (Diltiazem, Mustafa Nevzat), to the fourth group (PZP+diltiazem group). One hour after, and under anesthesia, QTc was calculated by recording ECG on lead I.

Results

The mean QTc interval values were as follows: normal group, 99.93 ± 3.62 ms; control-PZP+SP group, 131.23 ± 12.21 ms; PZP+metoprolol group, 89.36 ± 3.61 ms; and PZP+diltiazem group, 88.86 ± 4.04 ms. Both PZP+metoprolol and PZP+diltiazem groups had significantly shorter QTc intervals compared to the control-PZP+SP group (p < 0.001).

Conclusion

Both metoprolol and diltiazem prevented PZP-induced QT interval prolongation. These drugs may provide a promising prophylactic strategy for the prolonged QTc interval associated with tyrosine kinase inhibitor use.

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.

Targeted cancer therapy: giving histone deacetylase inhibitors all they need to succeed

Histone deacetylase inhibitors (HDACis) have now emerged as a powerful new class of small-molecule therapeutics acting through the regulation of the acetylation states of histone proteins (a form of epigenetic modulation) and other non-histone protein targets. Over 490 clinical trials have been initiated in the last 10 years, culminating in the approval of two structurally distinct HDACis - SAHA (vorinostat, Zolinza™) and FK228 (romidepsin, Istodax™). However, the current HDACis have serious limitations, including ineffectively low concentrations in solid tumors and cardiac toxicity, which is hindering their progress in the clinic. Herein, we review the primary paradigms being pursued to overcome these hindrances, including HDAC isoform selectivity, localized administration, and targeting cap groups to achieve selective tissue and cell type distribution.

Cardiotoxicity

Cancer treatment has improved extraordinarily in recent years. The development of targeted therapies has widened the cardiotoxic spectrum of antineoplastic drugs. Optimum management of cardiovascular disease before and during antineoplastic treatment is essential to reduce morbidity and mortality in cancer patients. This article reviews the incidence and characteristics of cardiotoxic effects of antineoplastic drugs with special focus on the pathophysiological mechanisms. It also emphasizes the importance of early detection and correction of cardiovascular risk factors and the relevance of close cardiac monitoring during antineoplastic treatment in order to reduce cardiotoxicity.

[Management of side-effects of targeted therapies in renal cancer: cardiovascular side-effects]

Several types of cardiovascular complications can occur during treatment with targeted therapies: heart failure, QTc lengthening, arterial and venous thrombosis. A clinical examination, ECG and cardiac ultrasound are essential before starting treatment with targeted therapy. Patients with no medical history, who are asymptomatic with a normal ECG and a left ventricular ejection fraction (LVEF) greater than 50% can begin molecular targeted therapy (MTT). Patients must be assessed by a cardiologist before the introduction of MTT if they have a history of ischemic or valvular heart disease, heart failure, atrial fibrillation, stroke, transient ischemic attack, or ECG anomalies (Q wave, supraventricular arrhythmia, QT greater than 500ms), or LVEF less than 50%. In patients who are symptomatic (dyspnoea, angina, syncope, embolism etc.) and/or present with a modification to the ECG or alteration to the LVEF, MTT must be stopped and reassessment by a cardiologist is indicated. The restarting of MTT following a cardiovascular complication must be subject to a multidisciplinary discussion taking into account the severity of the cardiac event, its reversibility with cardiac treatment, life expectancy of the patient as well as the expected efficacy of the drug.