Cancer and Cardiovascular Disease: The Conjoined Twins

Cancer and cardiovascular disease are the two most common causes of death worldwide. As the fields of cardiovascular medicine and oncology continue to expand, the area of overlap is becoming more prominent demanding dedicated attention and individualized patient care. We have come to realize that both fields are inextricably intertwined in several aspects, so much so that the mere presence of one, with its resultant downstream implications, has an impact on the other. Nonetheless, cardiovascular disease and cancer are generally approached independently. The focus that is granted to the predominant pathological entity (either cardiovascular disease or cancer), does not allow for optimal medical care for the other. As a result, ample opportunities for improvement in overall health care are being overlooked. Herein, we hope to shed light on the interconnected relationship between cardiovascular disease and cancer and uncover some of the unintentionally neglected intricacies of common cardiovascular therapeutics from an oncologic standpoint.

Use of computed tomography coronary calcium score for prediction of cardiovascular events in cancer patients: a retrospective cohort analysis

BACKGROUND

CT- coronary calcium score, is one of the most studied and widely available modalities in cardiovascular medicine. Coronary artery calcium score (CACS) is an established predictor of coronary artery disease. The 'standard of care' diagnostic modality to measure CACS is ECG-gated Cardiac Multi-Detector Computed Tomography. There is convincing evidence of a strong association between CACS and major cardiovascular (CV) events in asymptomatic individuals. Cancer patients (C) may have a higher risk for CV disease than non-cancer patients (NC) related not only to cancer treatments but also to shared biological factors and pathways. Thus, identifying tools for early detection of CV disease in this population is of utmost importance.

METHODS

A retrospective cohort analysis was performed with patients from Cleveland Clinic Florida and Ohio who had CACS from 2017 to 2021. Patients who had cancer diagnosis prior to CACS were matched to NC for age and sex. CV events after their index CACS events were compared between C and NC, and matched control and propensity analysis were conducted.

RESULTS

Ten thousand seven hundred forty-two patients had CACS; 703 cancer patients had CACS and were eligible. Extensive CACS (> 400) were significantly higher in cancer, 94 (13.37%) vs non-cancer patients, 76 (10.83%), P = 0.011. Furthermore, after propensity matched analysis, CACS > 400 was 14.8% in C vs 9.6% in NC, P =  < 0.05. CV events were similar in both cohorts (p = NS), despite less CV risk factors in cancer patients (P =  < 0.05). For the combined moderate (101-400) & extensive (> 400) CACS, the prevalence of stroke and peripheral arterial disease, a marker of systemic atherosclerosis, was significantly higher in patients with cancer (P < 0.01).

CONCLUSIONS

Despite having fewer CV risk factors in our study, similar CACS in cancer patients are suggestive of a higher prevalence of CV disease independent of traditional risk factors. High CACS and the overall prevalence of vascular events were more frequent in patients with cancer. Higher prevalence of peripheral arterial disease and cerebrovascular accident further suggests the increased atherosclerotic burden in C.

Global Cardio Oncology Registry (G-COR): Registry Design, Primary Objectives, and Future Perspectives of a Multicenter Global Initiative

BACKGROUND

Global collaboration in cardio-oncology is needed to understand the prevalence of cancer therapy-related cardiovascular toxicity in different risk groups, practice settings, and geographic locations. There are limited data on the socioeconomic and racial/ethnic disparities that may impact access to care and outcomes. To address these gaps, we established the Global Cardio-Oncology Registry, a multinational, multicenter prospective registry.

METHODS

We assembled cardiologists and oncologists from academic and community settings to collaborate in the first Global Cardio-Oncology Registry. Subsequently, a survey for site resources, demographics, and intention to participate was conducted. We designed an online data platform to facilitate this global initiative.

RESULTS

A total of 119 sites responded to an online questionnaire on their practices and main goals of the registry: 49 US sites from 23 states and 70 international sites from 5 continents indicated a willingness to participate in the Global Cardio-Oncology Registry. Sites were more commonly led by cardiologists (85/119; 72%) and were more often university/teaching (81/119; 68%) than community based (38/119; 32%). The average number of cardio-oncology patients treated per month was 80 per site. The top 3 Global Cardio-Oncology Registry priorities in cardio-oncology care were breast cancer, hematologic malignancies, and patients treated with immune checkpoint inhibitors. Executive and scientific committees and specific committees were established. A pilot phase for breast cancer using Research Electronic Data Capture Cloud platform recently started patient enrollment.

CONCLUSIONS

We present the structure for a global collaboration. Information derived from the Global Cardio-Oncology Registry will help understand the risk factors impacting cancer therapy-related cardiovascular toxicity in different geographic locations and therefore contribute to reduce access gaps in cardio-oncology care. Risk calculators will be prospectively derived and validated.

Cardio oncology: Digital innovations, precision medicine and health equity

The rapid emergence of cardio-oncology has resulted in a rapid growth of cardio-oncology programs, dedicated professional societies sections and committees, and multiple collaborative networks that emerged to amplify the access to care in this new subspecialty. However, most existing data, position statements and guidelines are limited by the lack of availability of large clinical trials to support these recommendations. Furthermore, there are significant challenges regarding proper access to cardio-oncology care and treatment, particularly in marginalized and minority populations. The emergence and evolution of personalized medicine, artificial intelligence (AI), and machine learning in medicine and in cardio-oncology provides an opportunity for a more targeted, personalized approach to cardiovascular complications of cancer treatment. The proper implementation of these new modalities may facilitate a more equitable approach to adequate and universal access to cardio-oncology care, improve health related outcomes, and enable health care systems to eliminate the digital divide. This article reviews and analyzes the current status on these important issues.

Immune checkpoint inhibitor induced myocarditis, myasthenia gravis, and myositis: A single-center case series

BACKGROUND

Immune checkpoint inhibitors can result in overlap syndrome comprised of myasthenia gravis, myositis and myocarditis. However, the mortality predictors have not been clearly delineated.

METHODS

We examined the characteristics of 11 patients diagnosed with overlap syndrome at Cleveland Clinic. All the available clinical, diagnostic, biochemical and disease specific factors were examined. Clinical predictors of increased mortality were using student t-test for parametric data and Wilcoxon-signed rank testing for nonparametric data.

RESULTS

Seven patients out of eleven patients were alive during the analysis. Our study did confirm that troponins were indicator of early demise. However, study showed that elevated creatinine, BUN, and decreased hemoglobin were also observed in patients who met early demise. Unlike previously published studies, elevated NT Pro-BNP and reduced left ventricular ejection fraction were not a seen in this study. However, there were higher incidence of electrical abnormalities in deceased patients when compared to alive.

CONCLUSION

Our study is first to examine various clinical parameters of overlap syndrome that might be predictive of mortality. This study confirms troponin as possible predictor and adds elevated creatinine, BUN and reduced hemoglobin as possible early biomarkers in deceased patients. The analysis showed that reduced LVEF was not a seen in deceased patients.

The Safety of Bruton's Tyrosine Kinase Inhibitors in B-cell Malignancies: A Systematic Review

B-cell malignancies, most notably lymphomas, make up most of the non-Hodgkin lymphomas in the United States. There is limited randomized data comparing 1^st and 2^nd generation Bruton Tyrosine Kinase inhibitors. Our aim was to compare the safety profiles of 1^st versus 2^nd generation Bruton Tyrosine Kinase inhibitors. A systematic search was performed from database inception to January 13, 2020. Studies with Bruton Tyrosine Kinase inhibitor monotherapy for the treatment of B-cell malignancies in the adult population (> 18 years old) were utilized and the adverse events were extracted. Fifty-five studies that met the inclusion criteria were included in the systematic review with forty-one studies with 1^st generation and fourteen studies with 2^nd generation. The review included both clinical trials and retrospective studies with average time of follow-up of 2 years for the 1^st generation group and 18 months for the 2^nd generation group. We found that the incidence of cardiovascular adverse events was significantly higher in the 1^st generation group (20.8%) as compared to the 2^nd generation group (6.3%). However, there was a higher incidence of hematologic/oncologic and gastrointestinal side effects in the 2^nd generation group compared to the 1^st (62.3% compared to 39.2% and 36.9% compare to 28.9%). The number of Grade 5 cardiovascular events (death) were same in the 1^st generation group compared to the 2^nd generation. Further research is needed to develop highly selective Bruton Tyrosine Kinase inhibitors to avoid unwanted adverse events by minimizing off-targets. This article is protected by copyright. All rights reserved.

Cardiovascular Complications in Major 21st Century Viral Epidemics and Pandemics: an Insight into COVID-19

There have many major history-defining epidemics and pandemics in the 21st century. It is well known that acute infections can cause cardiovascular (CV) complications, especially in those with underlying cardiac disease. The variation in rates and types of CVD complications in major 21st century epidemics and pandemics varies greatly. The coronavirus disease 2019 (COVID-19) pandemic has caused the turmoil of the century and has COVID-19 has resulted in substantial human and economic loss. The novelty of COVID-19 and emerging CV effects is a new entity. In this review, we discuss the major epidemics and pandemics of the 21st century and associated CVD complications.

COVID-19 and postural tachycardia syndrome: a case series

Background

Postural tachycardia syndrome (PTS) is a novel identified sequela of COVID-19 infection. This observational study describes clinical presentation, testing, and treatment response in seven patients diagnosed with PTS following COVID-19 infection.

Case summary

A total of seven active patients (three collegiate athletes, one recreational athlete, two registered nurses, one hospitality employee), age 24 ± 6 years, and six females were followed for a mean of 152 ± 105 days after contracting COVID-19. Tilt table was performed to establish the diagnosis. The most common presenting symptoms were palpitations (7/7), dyspnoea (6/7), and gastrointestinal complaints (5/7). One patient required hospitalization for symptom management. The mean latency of PTS onset following COVID-19 was 21 ± 15 days. Electrocardiograms (ECGs) demonstrated sinus rhythm in all patients, one with resting sinus tachycardia. Echocardiogram demonstrated normal systolic and diastolic left ventricular function in all patients. On tilt table testing, baseline heart rate (HR) was 72 ± 12 with maximum HR reaching 136 ± 13. Six of seven patients failed to respond to supportive therapy alone, and two patients failed medical management with ivabradine, midodrine, and/or metoprolol. Of three severely symptomatic patients, two demonstrated some degree of clinical recovery with intravenous immunoglobulin (IVIG).

Discussion

This novel case series describes the development of PTS in the context of COVID-19 infection. Severity of symptoms and response to treatment was heterogeneous. Interestingly, patients were poorly responsive to traditional PTS treatments, but IVIG showed potential as a possible therapeutic strategy for refractory PTS in two patients, particularly following COVID-19 infection.

Speckle-Tracking Echocardiography in Cardio-Oncology and Beyond

Speckle-tracking echocardiography has enabled clinicians to detect changes in myocardial function with more sensitivity than that afforded by traditional diastolic and systolic functional measurements, including left ventricular ejection fraction. Speckle-tracking echocardiography enables evaluation of myocardial strain in terms of strain (percent change in length of a myocardial segment relative to its length at baseline) and strain rate (strain per unit of time). Both measurements have potential for use in diagnosing and monitoring the cardiovascular side effects of cancer therapy. Regional and global strain measurements can independently predict outcomes not only in patients who experience cardiovascular complications of cancer and cancer therapy, but also in patients with a variety of other clinical conditions. This review and case series examine the clinical applications and overall usefulness of speckle-tracking echocardiography in cardio-oncology and, more broadly, in clinical cardiology.

Immune Checkpoint Inhibitors Mediated Lymphocytic and Giant Cell Myocarditis: Uncovering Etiological Mechanisms

The advent of immune checkpoint inhibitors (ICIs) has revolutionized the field of oncology, but these are associated with immune related adverse events. One such adverse event, is myocarditis, which has limited the continued immunosuppressive treatment options in patients afflicted by the disease. Pre-clinical and clinical data have found that specific ICI targets and precipitate distinct myocardial infiltrates, consistent with lymphocytic or giant cell myocarditis. Specifically, it has been reported that CTLA-4 inhibition preferentially results in giant cell myocarditis with a predominately CD4+ T cell infiltrate and PD-1 inhibition leads to lymphocytic myocarditis, with a predominately CD8+ T cell infiltrate. Our manuscript discusses the latest literature surrounding ICI pathways and targets, while detailing proposed mechanisms behind ICI mediated myocarditis.

Ixekizumab-Induced Cardiac Sarcoidosis: A Case Report

A 58-year-old man with a history of hypertension and psoriasis presented with acute-onset heart failure with an ejection fraction of 25%-30%. During the work-up, cardiac magnetic resonance imaging showed a pattern of inflammation consistent with sarcoidosis, which was confirmed with (18)F-fluorodeoxyglucose positron emission tomography . The patient was recently initiated on ixekizumab for psoriasis, which was then discontinued. This discontinuation resulted in complete resolution of cardiac sarcoidosis, with establishment of normal ejection fraction. This result suggests a potential causal association of ixekizumab-induced cardiac sarcoidosis, which is a rare phenomenon. Elucidation of the mechanism behind the effect of ixekizumab may provide insights into the possible mechanism(s) behind cardiac sarcoidosis.

Perspectives on the COVID-19 pandemic impact on cardio-oncology: results from the COVID-19 International Collaborative Network survey

BACKGROUND

Re-allocation of resources during the COVID-19 pandemic has resulted in delays in care delivery to patients with cardiovascular disease and cancer. The ability of health care providers to provide optimal care in this setting has not been formally evaluated.

OBJECTIVES

To assess the impact of COVID-19 resource re-allocation on scheduling, testing, elective procedures, telemedicine access, use of new COVID-19 therapies, and providers' opinions on healthcare policies among oncology and cardiology practitioners.

METHODS

An electronic survey was conducted by a cardio-oncology collaborative network through regional and state chapters of the American College of Cardiology, American Society of Clinical Oncology, and the International Cardio-Oncology Society. Descriptive statistics were reported by frequency and proportion for analyses, and stratified categorically by geographic region and specialty.

RESULTS

One thousand four hundred fifteen providers (43 countries) participated: 986 cardiologists, 306 oncologists, and 118 trainees/internal medicine. 63% (195/306) of oncologists vs 92% (896/976) of cardiologists reported cancellations of treatments/elective procedures (p = 0.01). 46% (442/970) of cardiologists and 25% (76/303) of oncologists modified the scope of their practice (p = < 0.001). Academic physicians (74.5%) felt better supplied with personal protective equipment (PPE) vs non-academic (74.5% vs 67.2%; p = 0.018). Telemedicine was less common in Europe 81% (74/91), and Latin America 64% (101/158), than the United States, 88% (950/1097) (p = < 0.001). 95% of all groups supported more active leadership from medical professional societies.

CONCLUSIONS

These results support initiatives to promote expanded coverage for telemedicine, increased access to PPE, better testing availability and involvement of medical professional societies to help with preparedness for future health care crisis.

Machine Learning-Based Risk Assessment for Cancer Therapy-Related Cardiac Dysfunction in 4300 Longitudinal Oncology Patients

Background The growing awareness of cardiovascular toxicity from cancer therapies has led to the emerging field of cardio-oncology, which centers on preventing, detecting, and treating patients with cardiac dysfunction before, during, or after cancer treatment. Early detection and prevention of cancer therapy-related cardiac dysfunction (CTRCD) play important roles in precision cardio-oncology. Methods and Results This retrospective study included 4309 cancer patients between 1997 and 2018 whose laboratory tests and cardiovascular echocardiographic variables were collected from the Cleveland Clinic institutional electronic medical record database (Epic Systems). Among these patients, 1560 (36%) were diagnosed with at least 1 type of CTRCD, and 838 (19%) developed CTRCD after cancer therapy (de novo). We posited that machine learning algorithms can be implemented to predict CTRCDs in cancer patients according to clinically relevant variables. Classification models were trained and evaluated for 6 types of cardiovascular outcomes, including coronary artery disease (area under the receiver operating characteristic curve [AUROC], 0.821; 95% CI, 0.815-0.826), atrial fibrillation (AUROC, 0.787; 95% CI, 0.782-0.792), heart failure (AUROC, 0.882; 95% CI, 0.878-0.887), stroke (AUROC, 0.660; 95% CI, 0.650-0.670), myocardial infarction (AUROC, 0.807; 95% CI, 0.799-0.816), and de novo CTRCD (AUROC, 0.802; 95% CI, 0.797-0.807). Model generalizability was further confirmed using time-split data. Model inspection revealed several clinically relevant variables significantly associated with CTRCDs, including age, hypertension, glucose levels, left ventricular ejection fraction, creatinine, and aspartate aminotransferase levels. Conclusions This study suggests that machine learning approaches offer powerful tools for cardiac risk stratification in oncology patients by utilizing large-scale, longitudinal patient data from healthcare systems.

Topoisomerase 2B Decrease Results in Diastolic Dysfunction via p53 and Akt: A Novel Pathway

Diastolic dysfunction is condition of a stiff ventricle and a function of aging. It causes significant cardiovascular mortality and morbidity, and in fact, three million Americans are currently suffering from this condition. To date, all the pharmacological clinical trials have been negative. The lack of success in attenuating/ameliorating diastolic dysfunction stems from lack of duplication of myriads of clinical manifestation in pre-clinical settings. Here we report, a novel genetically engineered mice which may represents a preclinical model of human diastolic dysfunction to some extent. Topoisomerase 2 beta (Top2b) is an important enzyme in transcriptional activation of some inducible genes through transient double-stranded DNA breakage events around promoter regions. We created a conditional, tissue-specific, inducible Top2b knockout mice in the heart. Serendipitously, echocardiographic parameters and more invasive analysis of left ventricular function with pressure–volume loops show features of diastolic dysfunction. This was also confirmed histologically. At the cellular level, the Top2b knockdown showed morphological changes and molecular signaling akin to human diastolic dysfunction. Reverse phase protein analysis showed activation of p53 and inhibition of, Akt, as the possible mediators of diastolic dysfunction. Finally, activation of p53 and inhibition of Akt were confirmed in myocardial biopsy samples obtained from human diastolic dysfunctional hearts. Thus, we report for the first time, a Top2b downregulated preclinical mice model for diastolic dysfunction which demonstrates that Akt and p53 are the possible mediators of the pathology, hence representing novel and viable targets for future therapeutic interventions in diastolic dysfunction.

Radiation induced cardiovascular disease: An odyssey of bedside-bench-bedside approach

The journey to Mars will be an ambitious, yet arduous task as it will entail culmination of all the information we have gathered over many decades. While the mission is of utmost importance, preservation of astronaut's well-being is paramount also. To that end, mitigation of radiation risk especially afflicting cardiovascular disease (CVD) is of great interest and challenge. Current data from astronauts on low earth orbit and Apollo missions provides insight on the risk of CVD from radiation exposure. However, data is limited given the small cohort size of astronauts who embarked on just nine prolonged missions. Therefore, a cerebral approach to understanding and mitigating risks are essential. This paper discusses the need for a predictive preclinical model to help understand and mitigate the effects of radiation on astronauts. We will discuss strengths and limitations of preclinical models and the methods of validating and constructing a model to predict human clinical outcomes. Our bedside-bench-bedside approach focuses on adapting the preclinical model through common investigative tools used between humans and animals. The result will be an optimization of preclinical model to a point of being a surrogate clinical model capable of predicting CVD outcomes in astronauts exposed to radiation.

Impact of timing of atrial fibrillation, CHA2DS2-VASc score and cancer therapeutics on mortality in oncology patients

OBJECTIVES

To investigate timing and age distribution of atrial fibrillation (AF) in selected oncology patients, and the impact of AF timing, CHA2DS2-VASc score and cancer therapeutics on mortality.

METHODS

This is a retrospective cohort study of oncology patients referred to the cardio-oncology service from 2011 to 2018 for echocardiographic cardiosurveillance and/or pre-existing cardiovascular risk factor/disease management. Rates of first AF diagnosis was assessed using a parametric multiphase hazard model (predictive modelling) and non-parametrically by Kaplan-Meier with transformations tested using a bootstrap methodology.

RESULTS

Among 6754 patients identified, 174 patients had their first AF diagnosis before cancer while 609 patients had their first diagnosis of AF after cancer. Most first AF diagnosis occurred at/early after cancer diagnosis. Increasing AF prevalence at time of cancer diagnosis was seen across older age groups ranges. Diagnosis of cancer at an older age and exposure to cardiotoxic treatment (anthracyclines, HER2-neu inhibitors, tyrosine kinase inhibitors including ibrutinib and radiation) were associated with an increased risk of AF.Modelling of the hazard function of AF identified a high left-skewed peak within 3 years after cancer diagnosis ('early phase'), followed by a gradual late slight rise 3 years after cancer diagnosis ('late phase'). AF diagnosis was only associated with death in the early phase (p<0.001), while CHA2DS2-VASc score was only associated with death in the late phase (p<0.001).

CONCLUSIONS

This study reports a nuanced/complex relationship between AF and cancer. First diagnosis of AF in patients with cancer was more common at/early after cancer diagnosis, especially in older patients and those exposed to cardiotoxic treatment. Pre-existing AF or a diagnosis of AF within 3 years after cancer diagnosis carried a negative prognosis. CHA2DS2-VASc score did not relate to mortality in those that developed AF within 3 years of cancer diagnosis.

Expression of T-cell populations and molecular markers of human myocardium with checkpoint-induced myocarditis

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Background: Checkpoint Inhibitors have become first line therapy for a variety of solid and liquid malignancy. Immunotherapeutic agents predominantly target CTLA-4 and PD-L1. Efficacy has been demonstrated, and toxicities, especially cardiac manifested as myocarditis. The incidence of myocarditis is relatively low, fatality with monotherapy approaches 50% and with dual Immunotherapy is over 75%. No screening biomarkers or cardiac imaging predict a priori whom will develop myocarditis, nor which patients will be at risk. The frequency of these targets are unknown in the human heart. Methods: We present a case study of a patient with a diagnosis of urothelial carcinoma to lung and lymph nodes treated with systemic nivolumab plus NKTR after cycle 2 he presented with one week history of shortness of breath and hemodynamically unstable complete heart block requiring temporary transvenous pacemaker. Initial Troponin = 356, BNP = 2106. Given high suspicion for cardiovascular disease and or myocarditis, a left heart angiogram, right heart catheterization and endomyocardial biopsy of right ventricle were performed. RV biopsies were obtained percutaneously from right internal jugular approach with fluoroscopic guidance. Pulmonary capillary wedge pressure was 23mmHg. Persistent complete heart block was present during weaning attempts from temporary pacemaker and a percutaneous dual chamber pacemaker was implanted. Results: Coronary angiogram showed non obstructive disease, endomyocardial biopsy revealed lymphocytic infiltrate with necrosis based on Dallas Criteria. Immunohistochemistry showed, predominance of CD3,CD4,CD8,CD20,CD68 and PD-L1 staining was grossly positive compared to control samples. The patient was treated with methylprednisone 1mg/kg IV BID, plasmapheresis times 5 cycles, mycophenolate mofetil 500mg IV BID with resolution of symptoms and discharged to home. Conclusions: We present a patient with nivolumab induced myocarditis complicated with myocarditis and complete heart block. The pathological approach of T-Cell phenotyping is unique and identifies a novel approach to precision driven diagnosis, the incidence of PD-L1 expression in the human heart is unknown.

Echocardiographic measures associated with the presence of left ventricular thrombus in patients with chemotherapy-related cardiac dysfunction

BACKGROUND

Previous studies have not evaluated the prevalence and specific risk factors for the development of left ventricular (LV) thrombus in patients with severely reduced left ventricular dysfunction due to chemotherapy-related cardiomyopathy. We sought to evaluate the prevalence and potential markers of LV thrombus in this patient population.

METHODS

From January 2009 to December 2013, patients with chemotherapy-related severe LV dysfunction (LV ejection fraction [LVEF] ≤ 30%) identified from MD Anderson Cancer Center database were reviewed. Patient characteristics and echocardiographic parameters were analyzed to determine potential risk factors for LV thrombus.

RESULTS

A total of 121 patients met inclusion criteria (age 54.8 ± 15.2 years; female 63.6%; LVEF 26.3 ± 4%). LV thrombus was present in 9 patients (7.4%). Patients with LV thrombus have significantly lower LVEF compared to those without (18.7 ± 3.8% vs 26.9 ± 3.4%, P < .0001). Prevalence of LV thrombus increased as LVEF decreased and was the highest in patients with LVEF < 20%. By univariate analysis, decreased LVEF, particularly LVEF < 20% (OR 36.30, 95% CI 7.35-179.25, P < .0001) and restrictive LV filling pattern (OR 18.13, 95% CI 4.17-78.89, P = .0001) were associated with presence of LV thrombus.

CONCLUSION

In patients with severely reduced LV systolic function due to chemotherapy-induced cardiomyopathy, LV thrombus was found in 7.4% of subjects. Severely decreased LVEF (<20%) and restrictive LV filling pattern were associated with the presence of LV thrombus.

Biomarkers in cancer therapy related cardiac dysfunction (CTRCD)

Biomarkers are at the cornerstone of preventive measures and contribute to the screening process. More recently, biomarkers have been used to gauge the biological response to the employed therapies. Since it is ubiquitously used to detect subclinical disease process, biomarkers also have found its place in cancer therapy related cardiac dysfunction (CTRCD). The aim of this review is to comprehensively present up-to-date knowledge of biomarkers in CTRCD and highlight some of the future biomedical technologies that may strengthen the screening process, and/or provide new insight in pathological mechanisms behind CTRCD.

Cardiovascular Complications of Cancer Therapy: Best Practices in Diagnosis, Prevention, and Management: Part 1

Modern cancer therapy has successfully cured many cancers and converted a terminal illness into a chronic disease. Because cancer patients often have coexisting heart diseases, expert advice from cardiologists will improve clinical outcome. In addition, cancer therapy can also cause myocardial damage, induce endothelial dysfunction, and alter cardiac conduction. Thus, it is important for practicing cardiologists to be knowledgeable about the diagnosis, prevention, and management of the cardiovascular complications of cancer therapy. In this first part of a 2-part review, we will review cancer therapy-induced cardiomyopathy and ischemia. This review is based on a MEDLINE search of published data, published clinical guidelines, and best practices in major cancer centers. With the number of cancer survivors expanding quickly, the time has come for cardiologists to work closely with cancer specialists to prevent and treat cancer therapy-induced cardiovascular complications.

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.

Association between ibrutinib and mid-cavitary Takotsubo cardiomyopathy: a case report and a review of chemotherapy-induced Takostubo's cardiomyopathy

Takotsubo cardiomyopathy (TC) is a rare but increasingly recognized phenomenon, which can occur as a side effect of cancer treatment. We report an interesting case of a 53-year-old woman with non-small-cell lung cancer, who developed TC after chemotherapy with ibrutinib. Echocardiography revealed marked left ventricular dysfunction with apical hyperkinesis and mid-ventricular hypokinesia. Coronary angiogram was normal but did show mid-cavitary akinesis. To our knowledge, this is the first case of TC with ibrutinib. Therefore, TC remains a rare entity, and we present an elegant case of ibrutinib-mediated mid-cavitary Takotsubo cardiomyopathy with a literature review.

Progressive and Reversible Conduction Disease With Checkpoint Inhibitors

Novel antineoplastic therapies are focused on harnessing our own immune system to fight cancer. To that end, cytotoxic T-lymphocyte-associated antigen 4 and programmed death ligand 1 are 2 coinhibitory signals that play central roles in decreasing T-cell response and represent a class of medications termed "checkpoint inhibitors." We present an unusual case of progressive conduction abnormalities induced by checkpoint inhibitors. Prompt medical intervention resulted in full recovery. Despite the anticancer efficacy, the newer antineoplastic agents pose a significant and often life-threatening risk of cardiotoxicity.

Mechanisms of Cardiotoxicity of Cancer Chemotherapeutic Agents: Cardiomyopathy and Beyond

Tremendous strides have been made in the treatment of various oncological diseases such that patients are surviving longer and are having better quality of life. However, the success has been tainted by the iatrogenic cardiac toxicities. This is especially concerning in the younger population who are facing cardiac disease such as heart failure in their 30s and 40s as the consequence of the anthracycline's side effects (used for childhood leukemia and lymphoma). This resulted in the awareness of cardiotoxic effects of anticancer drugs and emergence of a new discipline: oncocardiology. Since then, numerous anticancer drugs have been correlated to cardiomyopathy. Additionally, other cardiovascular effects have been identified, which includes but is not limited to myocardial infarction, thrombosis, hypertension, arrhythmias, and pulmonary hypertension. In this review we examine some of the anticancer agents that mitigate cardiotoxicity and present current knowledge of molecular mechanism(s). The aim of the review is to ignite awareness of emerging cardiotoxic effects as new generations of anticancer agents are being tested in clinical trials and introduced as part of the therapeutic armamentarium to our oncological patients.

A comparative pharmacodynamic study of ticagrelor versus clopidogrel and ticagrelor in patients undergoing primary percutaneous coronary intervention: the CAPITAL RELOAD study

Background

In patients undergoing primary percutaneous coronary intervention (PPCI) ticagrelor is superior to clopidogrel in reducing cardiovascular events. This study sought to evaluate the effect of clopidogrel pretreatment on the pharmacodynamics of ticagrelor in patients undergoing PPCI.

Methods

We measured platelet reactivity using the VerifyNow P2Y12 assay at baseline, 1, 2, 4, 6, 12, 24, and 48 hours following ticagrelor bolus in patients previously loaded with clopidogrel (C+T) and in thienopyridine-naive patients (T) referred to our centre for PPCI.

Results

In total, 52 consecutive eligible patients with ST-elevation myocardial infarction (STEMI) were enrolled (27 C+T and 25 T). Baseline characteristics and mean baseline platelet reactivity units (PRUs) were similar between the groups. The primary endpoint, the proportion of patients achieving a PRU<208 at 2 hours, was more frequently achieved in the C+T group compared to T treatment (76.0% vs 44.4%, p = 0.026). Notably, C+T therapy resulted in fewer patients with high platelet reactivity at 1 hour (56.0% vs. 14.8%), 4 hours (100.0% vs. 61.5%) and 6 hours (100.0% vs. 64%, p<0.01 for all comparisons). Furthermore, C+T therapy was associated with lower PRU values from 2 to 48 hours.

Conclusions

In patients referred for PPCI, ticagrelor bolus following clopidogrel resulted in more rapid and profound platelet inhibition, demonstrating a positive pharmacodynamic interaction. Further study is needed to determine if this pharmacodynamic effect translates into reduced clinical events.

Phosphodiesterase Type 5 Is Highly Expressed in the Hypertrophied Human Right Ventricle, and Acute Inhibition of Phosphodiesterase Type 5 Improves Contractility

BACKGROUND

Sildenafil was recently approved for the treatment of pulmonary arterial hypertension. The beneficial effects of phosphodiesterase type 5 (PDE5) inhibitors in pulmonary arterial hypertension are thought to result from relatively selective vasodilatory and antiproliferative effects on the pulmonary vasculature and, on the basis of early data showing lack of significant PDE5 expression in the normal heart, are thought to spare the myocardium.

METHODS AND RESULTS

We studied surgical specimens from 9 patients and show here for the first time that although PDE5 is not expressed in the myocardium of the normal human right ventricle (RV), mRNA and protein are markedly upregulated in hypertrophied RV (RVH) myocardium. PDE5 also is upregulated in rat RVH. PDE5 inhibition (with either MY-5445 or sildenafil) significantly increases contractility, measured in the perfused heart (modified Langendorff preparation) and isolated cardiomyocytes, in RVH but not normal RV. PDE5 inhibition leads to increases in both cGMP and cAMP in RVH but not normal RV. Protein kinase G activity is suppressed in RVH, explaining why the PDE5 inhibitor-induced increase in cGMP does not lead to inhibition of contractility. Rather, it leads to inhibition of the cGMP-sensitive PDE3, explaining the increase in cAMP and contractility. This is further supported by our findings that, in RVH protein kinase A, inhibition completely inhibits PDE5-induced inotropy, whereas protein kinase G inhibition does not.

CONCLUSIONS

The ability of PDE5 inhibitors to increase RV inotropy and to decrease RV afterload without significantly affecting systemic hemodynamics makes them ideal for the treatment of diseases affecting the RV, including pulmonary arterial hypertension.

Oxygen activates the Rho/Rho-kinase pathway and induces RhoB and ROCK-1 expression in human and rabbit ductus arteriosus by increasing mitochondria-derived reactive oxygen species: a newly recognized mechanism for sustaining ductal constriction

BACKGROUND

Constriction of the ductus arteriosus (DA) is initiated at birth by inhibition of O2-sensitive K+ channels in DA smooth muscle cells. Subsequent membrane depolarization and calcium influx through L-type calcium channels initiates functional closure. We hypothesize that Rho-kinase activation is an additional mechanism that sustains DA constriction.

METHODS AND RESULTS

The effect of increased PO2 on the activity and expression of Rho-kinase was assessed in DAs from neonates with hypoplastic left-heart syndrome (n=15) and rabbits (339 term and 99 preterm rabbits). Rho-kinase inhibitors (Y-27632 and fasudil) prevent and reverse O2 constriction. Heterogeneity exists in the sensitivity of constrictors (PO2=endothelin=phenylephrine>KCl) and of fetal vessels (DA=pulmonary artery>aorta) to Rho-kinase inhibition. Inhibition of L-type calcium channels (nifedipine) or removal of extracellular calcium inhibits approximately two thirds of O2 constriction. Residual DA constriction reflects calcium sensitization, which persists after removal of extracellular calcium and blocking of sarcoplasmic reticulum Ca2+-ATPase. In term DA, an increase in PO2 activates Rho-kinase and thereby increases RhoB and ROCK-1 expression. Activation of Rho-kinase in DA smooth muscle cells is initiated by a PO2-dependent, rotenone-sensitive increase in mitochondrion-derived reactive O2 species. O2 effects on Rho-kinase are mimicked by exogenous H2O2. In preterm DAs, immaturity of mitochondrial reactive oxygen species generation is associated with reduced and delayed O2 constriction and lack of PO2-dependent upregulation of Rho-kinase expression.

CONCLUSIONS

O2 activates Rho-kinase and increases Rho-kinase expression in term DA smooth muscle cells by a redox-regulated, positive-feedback mechanism that promotes sustained vasoconstriction. Conversely, Rho-kinase inhibitors may be useful in maintaining DA patency, as a bridge to congenital heart surgery.

The role of k+ channels in determining pulmonary vascular tone, oxygen sensing, cell proliferation, and apoptosis: implications in hypoxic pulmonary vasoconstriction and pulmonary arterial hypertension

Potassium channels are tetrameric, membrane-spanning proteins that selectively conduct K+ at near diffusion-limited rates. Their remarkable ionic selectivity results from a highly-conserved K+ recognition sequence in the pore. The classical function of K+ channels is regulation of membrane potential (EM) and thence vascular tone. In pulmonary artery smooth muscle cells (PASMC), tonic K+ egress, driven by a 145/5 mM intracellular/extracellular concentration gradient, contributes to a EM of about -60 mV. It has been recently discovered that K+ channels also participate in vascular remodeling by regulating cell proliferation and apoptosis. PASMC express voltage-gated (Kv), inward rectifier (Kir), calcium-sensitive (KCa), and two-pore (K2P) channels. Certain K+ channels are subject to rapid redox regulation by reactive oxygen species (ROS) derived from the PASMC's oxygen-sensor (mitochondria and/or NADPH oxidase). Acute hypoxic inhibition of ROS production inhibits Kv1.5, which depolarizes EM, opens voltage-sensitive, L-type calcium channels, elevates cytosolic calcium, and initiates hypoxic pulmonary vasoconstriction (HPV). Hypoxia-inhibited K+ currents are not seen in systemic arterial SMCs. Kv expression is also transcriptionally regulated by HIF-1alpha and NFAT. Loss of PASMC Kv1.5 and Kv2.1 contributes to the pathogenesis of pulmonary arterial hypertension (PAH) by causing a sustained depolarization, which increases intracellular calcium and K+, thereby stimulating cell proliferation and inhibiting apoptosis, respectively. Restoring Kv expression (via Kv1.5 gene therapy, dichloroacetate, or anti-survivin therapy) reduces experimental PAH. Electrophysiological diversity exists within the pulmonary circulation. Resistance PASMC have a homogeneous Kv current (including an oxygen-sensitive component), whereas conduit PASMC current is a Kv/KCa mosaic. This reflects regional differences in expression of channel isoforms, heterotetramers, splice variants, and regulatory subunits as well as mitochondrial diversity. In conclusion, K+ channels regulate pulmonary vascular tone and remodeling and constitute potential therapeutic targets in the regression of PAH.

Overexpression of human bone morphogenetic protein receptor 2 does not ameliorate monocrotaline pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is associated with mutations of bone morphogenetic protein receptor 2 (BMPR2), and BMPR2 expression decreases with the development of experimental PAH. Decreased BMPR2 expression and impaired intracellular BMP signaling in pulmonary artery (PA) smooth muscle cells (PASMC) suppresses apoptosis and promotes proliferation, thereby contributing to the pathogenesis of PAH. We hypothesized that overexpression of BMPR2 in resistance PAs would ameliorate established monocrotaline PAH. Human BMPR2 was inserted into a serotype 5 adenovirus with a green fluorescent protein (GFP) reporter. Dose-dependent transgene expression was confirmed in PASMC using fluorescence microscopy, quantitative RT-PCR, and immunoblots. PAH was induced by injecting Sprague-Dawley rats with monocrotaline (60 mg/kg ip) or saline. On day 14, post-monocrotaline (MCT) rats received 5 x 10(9) plaque-forming units of either Ad-human BMPR2 (Ad-hBMPR2) or Ad-GFP. Transgene expression was confirmed by fluorescence microscopy, quantitative RT-PCR of whole lung samples, and laser-capture microdissected resistance PAs. Invasive hemodynamic and echocardiographic end points of pulmonary hypertension were assessed on day 24. Endogenous BMPR2 mRNA levels were greatest in resistance PAs, and expression declined with MCT PAH. Despite robust hBMPR2 expression in all lung lobes and within resistance PAs of treated rats, hBMPR2 did not lower mean PA pressure, pulmonary vascular resistance index, right ventricular hypertrophy, or remodeling of resistance PAs. Nebulized intratracheal adenoviral gene therapy with hBMPR2 reliably distributed hBMPR2 to resistance PAs but did not ameliorate PAH. Depressed BMPR2 expression may be a marker of PAH but is not central to the pathogenesis of this model of PAH.

An Abnormal Mitochondrial–Hypoxia Inducible Factor-1α–Kv Channel Pathway Disrupts Oxygen Sensing and Triggers Pulmonary Arterial Hypertension in Fawn Hooded Rats

Background— The cause of pulmonary arterial hypertension (PAH) was investigated in humans and fawn hooded rats (FHR), a spontaneously pulmonary hypertensive strain.

Methods and Results— Serial Doppler echocardiograms and cardiac catheterizations were performed in FHR and FHR/BN1, a consomic control that is genetically identical except for introgression of chromosome 1. PAH began after 20 weeks of age, causing death by &60 weeks. FHR/BN1 did not develop PAH. FHR pulmonary arterial smooth muscle cells (PASMCs) had a rarified reticulum of hyperpolarized mitochondria with reduced expression of electron transport chain components and superoxide dismutase-2. These mitochondrial abnormalities preceded PAH and persisted in culture. Depressed mitochondrial reactive oxygen species (ROS) production caused normoxic activation of hypoxia inducible factor (HIF-1α), which then inhibited expression of oxygen-sensitive, voltage-gated K + channels (eg, Kv1.5). Disruption of this mitochondrial-HIF-Kv pathway impaired oxygen sensing (reducing hypoxic pulmonary vasoconstriction, causing polycythemia), analogous to the pathophysiology of chronically hypoxic Sprague-Dawley rats. Restoring ROS (exogenous H 2 O 2 ) or blocking HIF-1α activation (dominant-negative HIF-1α) restored Kv1.5 expression/function. Dichloroacetate, a mitochondrial pyruvate dehydrogenase kinase inhibitor, corrected the mitochondrial-HIF-Kv pathway in FHR-PAH and human PAH PASMCs. Oral dichloroacetate regressed FHR-PAH and polycythemia, increasing survival. Chromosome 1 genes that were dysregulated in FHRs and relevant to the mitochondria-HIF-Kv pathway included HIF-3α (an HIF-1α repressor), mitochondrial cytochrome c oxidase, and superoxide dismutase-2. Like FHRs, human PAH-PASMCs had dysmorphic, hyperpolarized mitochondria; normoxic HIF-1α activation; and reduced expression/activity of HIF-3α, cytochrome c oxidase, and superoxide dismutase-2.

Conclusions— FHRs have a chromosome 1 abnormality that disrupts a mitochondria-ROS-HIF-Kv pathway, leading to PAH. Similar abnormalities occur in idiopathic human PAH. This study reveals an intersection between oxygen-sensing mechanisms and PAH. The mitochondria-ROS-HIF-Kv pathway offers new targets for PAH therapy.

A central role for oxygen-sensitive K+ channels and mitochondria in the specialized oxygen-sensing system

Mammals possess a specialized O2-sensing system (SOS), which compensates for encounters with hypoxia that occur during development, disease, and at altitude. Consisting of the resistance pulmonary arteries (PA), ductus arteriosus, carotid body, neuroepithelial body, systemic arteries, fetal adrenomedullary cell and fetoplacental arteries, the SOS optimizes O2-uptake and delivery. Hypoxic pulmonary vasoconstriction (HPV), a vasomotor response of resistance PAs to alveolar hypoxia, optimizes ventilation/perfusion matching and systemic pO2. Though modulated by the endothelium, HPV's core mechanism resides in the smooth muscle cell (SMC). The Redox Theory proposes that HPV results from the coordinated action of a redox sensor (proximal mitochondrial electron transport chain) which generates a diffusible mediator (a reactive O2 species, ROS) that regulates effector proteins (voltage-gated K(v) channels). Hypoxic withdrawal of ROS inhibits K(v)1.5 and K(v)2.1, depolarizes PASMCs, activates voltage-gated Ca2+ channels, increasing Ca2+ influx and causing vasoconstriction. Hypoxia's effect on ROS (decrease vs. increase) and the molecular origins of ROS (mitochondria vs. NADPH oxidase) remains controversial. Distal to this pathway, Rho kinase regulates the contractile apparatus' sensitivity to Ca2+. Also, a role for cADP ribose as a redox-regulated mediator of intracellular Ca2+ release has been proposed. Despite tissue heterogeneity in the SOS's output (vasomotion versus neurosecretion), O2-sensitive K+ channels constitute a conserved effector mechanism. Disorders of the O2-sensing may contribute to diseases, such as pulmonary hypertension.