Cardiovascular late effects and the ongoing care of adult cancer survivors

A Comprehensive Review of Dilated Cardiomyopathy in Pre-clinical Animal Models in Addition to Herbal Treatment Options and Multi-modality Imaging Strategies

Dilated cardiomyopathy (DCM) is distinguished by ventricular chamber expansion, systolic dysfunction, and normal left ventricular (LV) wall thickness, and is mainly caused due to genetic or environmental factors; however, its aetiology is undetermined in the majority of patients. The focus of this work is on pathogenesis, small animal models, as well as the herbal medicinal approach, and the most recent advances in imaging modalities for patients with dilated cardiomyopathy. Several small animal models have been proposed over the last few years to mimic various pathomechanisms that contribute to dilated cardiomyopathy. Surgical procedures, gene mutations, and drug therapies are all characteristic features of these models. The pros and cons, including heart failure stimulation of extensively established small animal models for dilated cardiomyopathy, are illustrated, as these models tend to procure key insights and contribute to the development of innovative treatment techniques for patients. Traditional medicinal plants used as treatment in these models are also discussed, along with contemporary developments in herbal therapies. In the last few decades, accurate diagnosis, proper recognition of the underlying disease, specific risk stratification, and forecasting of clinical outcome, have indeed improved the health of DCM patients. Cardiac magnetic resonance (CMR) is the bullion criterion for assessing ventricular volume and ejection fraction in a reliable and consistent direction. Other technologies, like strain analysis and 3D echocardiography, have enhanced this technique's predictive and therapeutic potential. Nuclear imaging potentially helps doctors pinpoint the causative factors of left ventricular dysfunction, as with cardiac sarcoidosis and amyloidosis.

Anticancer drug and ionizing radiation-induced DNA damage differently influences transcription activity and DDR-related stress responses of an endothelial monolayer

The endothelium contributes to the pathophysiology of adverse effects caused by conventional (genotoxic) anticancer therapeutics (cAT). The relevance of structurally different types of cAT-induced DNA lesions for eliciting selected endothelial stress responses is largely unknown. Here, we analyzed the cAT-induced formation of DNA double-strand breaks (DSB), transcription blockage and DNA damage response (DDR) in time kinetic analyses employing a monolayer of primary human endothelial cells (HUVEC). We observed that the degree of cAT-induced transcription blockage, the number of DSB and activation of DDR-related factors diverge. For instance, ionizing radiation caused the formation of numerous DSB and triggerd a substantial activation of ATM/Chk2 signaling, which however were not accompanied by a significant transcription inhibition. By contrast, the DNA cross-linking cAT cisplatin triggered a rapid and substantial blockage of transcription, which yet was not reflected by an appreciable number of DSB or increased levels of pATM/pChk2. In general, cAT-stimulated ATM-dependent phosphorylation of Kap1 (Ser824) and p53 (Ser15) reflected best cAT-induced transcription blockage. In conclusion, cAT-induced formation of DSB and profound activation of prototypical DDR factors is independent of the inhibition of RNA polymerase II-regulated transcription in an endothelial monolayer. We suggest that DSB formed directly or indirectly following cAT-treatment do not act as comprehensive triggers of superior signaling pathways shutting-down transcription while, at the same time, causing an appreciable stimulation of the DDR. Rather, it appears that distinct cAT-induced DNA lesions elicit diverging signaling pathways, which separately control transcription vs. DDR activity in the endothelium.

Circuit resistance training and cardiovascular health in breast cancer survivors

OBJECTIVE

Cardiovascular disease is the leading cause of death in breast cancer survivors. While evidence shows circuit resistance training (CRT) is effective for improving muscle and cardiorespiratory fitness, whether CRT is an efficacious therapy for decreasing cardiovascular risk in cancer survivors is unclear.

METHODS

Fifty-one breast cancer survivors were recruited to either 12 weeks CRT (n = 26), or a non-exercising wait-list control (n = 25). Two supervised 60 min CRT sessions per week were undertaken, comprising resistance and functional exercises, and aerobic exercise stations. Primary outcome measure was the gold-standard assessment of arterial stiffness, aortic pulse wave velocity (PWV). Secondary outcomes included: cardiorespiratory fitness (CRF), upper and lower body strength, arterial wave reflections, central blood pressure and rate pressure product.

RESULTS

Compared to the control group, the CRT group had a statistically significant medium effect decrease in PWV 0.9 m/s (95% CI: 0.1, 1.7). There were large effect improvements in VO₂ max (4.3 ml kg^-1  min^-1 , 95% CI: 5.8, 2.8), upper and lower body strength (3.7 kg, 95% CI: 1.9, 5.6 and 10.4 kg, 1.6, 19.1) respectively.

CONCLUSION

Findings support the existing literature demonstrating that 12 weeks CRT improves muscle and cardiorespiratory fitness and is also an effective strategy for decreasing a proven cardiovascular risk factor in breast cancer survivors.

Cardiomyopathies: Evolution of pathogenesis concepts and potential for new therapies

Cardiomyopathies are defined as diseases of the myocardium with associated structural and functional abnormalities. Knowledge of these pathologies for a long period was not clear in clinical practice due to uncertainties regarding definition, classification and clinical diagnosis. In recent decades, major advances have been made in the understanding of the molecular and genetic issues, pathophysiology, and clinical and radiological assessment of the diseases. Progress has been made also in management of several types of cardiomyopathy. Advances in the understanding of these diseases show that cardiomyopathies represent complex entities. Here, special attention is given to evolution of classification of cardiomyopathies, with the aim of assisting clinicians to look beyond schematic diagnostic labels in order to achieve more specific diagnosis. Knowledge of the genotype of cardiomyopathies has changed the pathophysiological understanding of their etiology and clinical course, and has become more important in clinical practice for diagnosis and prevention of cardiomyopathies. New approaches for clinical and prognostic assessment are provided based on contemporary molecular mechanisms of contribution in the pathogenesis of cardiomyopathies. The genotype-phenotype complex approach for assessment improves the clinical evaluation and management strategies of these pathologies. The review covers also the important role of imaging methods, particularly echocardiography, and cardiac magnetic resonance imaging in the evaluation of different types of cardiomyopathies. In summary, this review provides complex presentation of current state of cardiomyopathies from genetics to management aspects for cardiovascular specialists.

Asymptomatic cardiac toxicity in long-term cancer survivors: defining the population and recommendations for surveillance

Advances in the treatment of pediatric and adult cancer have reduced the mortality rates from these disorders and have led to an ever-increasing population of long-term survivors. Chemotherapy and radiotherapy may cause premature cardiac disease that may be asymptomatic or symptomatic. All patients exposed to chemotherapy with cardiotoxic potential or chest radiotherapy have stage A heart failure and the goal of surveillance and treatment is to prevent progression to stages B-D. Screening strategies, including the use of biomarkers, echocardiography, and expert opinion surveillance and treatment recommendations, are presented.

Control of cardiovascular risk factors among adult cancer survivors: a population-based survey

INTRODUCTION

Cardiovascular disease (CVD) is a major cause of morbidity and mortality in cancer survivors, with the risk increasing significantly with the presence of multiple cardiac risk factors (RF). The proportion of cancer survivors at elevated risk of CVD on the basis of multiple RF is unknown.

METHODS

The National Health and Nutrition Examination Survey (NHANES 1999-2006) was used to examine the proportion of cancer survivors with multiple RF (≥2RF) and those at high cardiac risk (≥4 RF) compared with matched controls. RF (hypertension, hypercholesterolemia, weight, exercise, smoking) were defined according to AHA/ACC.

RESULTS

A total of 1,227 cancer survivors and 4,782 controls were identified. The majority of both cancer survivors and controls had multiple RF (91.5 vs. 89.9%) with a substantial proportion at high cardiac risk (35.2 vs. 32.6%). Compared to controls, survivors were more likely to be smokers (34.5 vs. 25.7%, p = 0.001), but less likely be overweight (67.2 vs. 72.0%, p = 0.02). There was no significant difference in the proportion with hypertension (30.6 vs. 30.8%), hypercholesterolemia (52.4 vs. 54.7%) or low exercise (75.6 vs. 73.0%). Among survivors, only age was associated with RF; with older survivors significantly more likely to have poor control than younger survivors (p = 0.005).

CONCLUSION

The prevalence of multiple RF was similar but suboptimal among cancer survivors and controls. Cardiac RF control, particularly among older survivors, is an important area of focus for improvement in survivorship care.