New Insights in Early Detection of Anticancer Drug-Related Cardiotoxicity Using Perfusion and Metabolic Imaging

Myocardial blood flow in newly diagnosed breast cancer patients at rest and during exercise

The heart depends critically on continuous blood supply, but it is unknown whether cancer itself affects myocardial blood flow (MBF). This study investigated MBF in cancer patients and cardiac morphology in a cancer mice model. MBF was quantified with [15O]H2O positron emission tomography at rest in recently diagnosed breast cancer patients and age-matched female controls, and additionally during 10-min exercise in the cancer patients. Cardiac morphological changes were analyzed with a breast cancer mouse model and control mice without tumors. Resting MBF was similar in cancer patients and controls. MBF increased significantly during exercise in cancer patients, and exercising MBF correlated positively with cancer grade. In the mouse model, cancer did not affect heart weight, cardiomyocyte size, myocardial capillary density, or capillary-to-myocyte size ratio. Thus, resting MBF in humans or myocardial capillarity in mice appears not to be affected by breast cancer. The exercise-induced MBF increase in cancer patients with higher histologic grade requires further investigations.

A pilot survey of breast cancer survivors' reporting of palpitations to healthcare providers

BACKGROUND

Breast cancer survivors (BCS) may experience cardiotoxicities from chemotherapy and oral endocrine therapy. Although a few studies have documented that palpitations are prevalent and associated with poorer outcomes, there is limited to no information on BCS' reporting of palpitations to healthcare providers.

OBJECTIVES

To compare BCS who did and did not report their palpitations to a healthcare provider and describe how those who did report palpitations recalled their provider responding.

DESIGN

This was a cross-sectional, national, electronic, pilot survey of BCS enrolled in the Love Army of Women registry.

METHODS

Participants (n = 52 with palpitations) completed standardized and investigator-designed questionnaires. Data were analyzed using frequency and descriptive statistics, chi-square tests, and Mann-Whitney tests. Responses to one open-ended question were analyzed using frequency counts and standard content analysis.

RESULTS

Compared to BCS who reported palpitations to a provider (n = 34), BCS who did not report their palpitations (n = 18) were significantly more anxious (p = 0.002) and more likely to feel palpitations as an irregular heartbeat (70.6% versus 38.9%, p = 0.027). Among the 34 BCS who reported palpitations to a provider, 32 completed the open-ended question. Of these 32 BCS, a majority (n = 27, 84%) indicated their provider recommended cardiac testing and/or referral to a cardiologist. Most (n = 24) reported completing testing. Test results included diagnosis of a new arrhythmia or other cardiac abnormality (n = 11, 46%), receipt of a new prescription (n = 5, 21%), or normal results (n = 5, 21%). Five (16%) of the 32 BCS did not receive recommendations for testing or referral and felt their provider normalized or dismissed their symptoms.

CONCLUSION

Palpitations are a salient topic for further research and clinical practice recommendations to address cardiac health in BCS.

Tales from the future-nuclear cardio-oncology, from prediction to diagnosis and monitoring

Cancer and cardiovascular diseases (CVD) often share common risk factors, and patients with CVD who develop cancer are at high risk of experiencing major adverse cardiovascular events. Additionally, cancer treatment can induce short- and long-term adverse cardiovascular events. Given the improvement in oncological patients' prognosis, the burden in this vulnerable population is slowly shifting towards increased cardiovascular mortality. Consequently, the field of cardio-oncology is steadily expanding, prompting the need for new markers to stratify and monitor the cardiovascular risk in oncological patients before, during, and after the completion of treatment. Advanced non-invasive cardiac imaging has raised great interest in the early detection of CVD and cardiotoxicity in oncological patients. Nuclear medicine has long been a pivotal exam to robustly assess and monitor the cardiac function of patients undergoing potentially cardiotoxic chemotherapies. In addition, recent radiotracers have shown great interest in the early detection of cancer-treatment-related cardiotoxicity. In this review, we summarize the current and emerging nuclear cardiology tools that can help identify cardiotoxicity and assess the cardiovascular risk in patients undergoing cancer treatments and discuss the specific role of nuclear cardiology alongside other non-invasive imaging techniques.

Role of advanced cardiovascular imaging in chemotherapy-induced cardiotoxicity

The development of cardiotoxicity induced by cancer treatments has emerged as a significant clinical problem, both in the short run, as it may influence drug administration in chemotherapeutic protocols, and in the long run, because it may determine adverse cardiovascular outcomes in survivors of various malignant diseases. Therefore, early detection of anticancer drug-related cardiotoxicity is an important clinical target to improve prevention of adverse effects and patient care. Today, echocardiography is the first-line cardiac imaging techniques used for identifying cardiotoxicity. Cardiac dysfunction, clinical and subclinical, is generally diagnosed by the reduction of left ventricular ejection fraction (LVEF) and global longitudinal strain (GLS). However, myocardial injury detected by echocardiography is preceded by other alterations, such as myocardial perfusion and mitochondrial and metabolic dysfunction, that can only be recognized by second-level imaging techniques, like cardiac magnetic resonance (CMR) and nuclear imaging, which, using targeted radiotracers, may help to provide information on the specific mechanisms of cardiotoxicity. In this review, we focus on the current and emerging role of CMR, as a critical diagnostic tool of cardiotoxicity in the very early phase, due to its availability and because it allows the contemporary detection of functional alterations, tissue alterations (mainly performed using T1, T2 mapping with the evaluation of extracellular volume-ECV) and perfusional alteration (evaluated with rest-stress perfusion) and, in the next future, even metabolic changes. Moreover, in the subsequent future, the use of Artificial Intelligence and big data on imaging parameters (CT, CMR) and oncoming molecular imaging datasets, including differences for gender and countries, may help predict cardiovascular toxicity at its earliest stages, avoiding its progression, with precise tailoring of patients' diagnostic and therapeutic pathways.

Anthracycline cardiotoxicity: current methods of diagnosis and possible role of 18F-FDG PET/CT as a new biomarker

Despite advances in chemotherapy, the drugs used in cancer treatment remain rather harmful to the cardiovascular system, causing structural and functional cardiotoxic changes. Positron-emission tomography associated with computed tomography (PET/CT) has emerged like a promising technique in the early diagnosis of these adverse drug effects as the myocardial tissue uptake of fluorodeoxyglucose labeled with fluorine-18 (¹⁸F-FDG), a glucose analog, is increased after their use. Among these drugs, anthracyclines are the most frequently associated with cardiotoxicity because they promote heart damage through DNA breaks, and induction of an oxidative, proinflammatory, and toxic environment. This review aimed to present the scientific evidence available so far regarding the use of ¹⁸F-FDG PET/CT as an early biomarker of anthracycline-related cardiotoxicity. Thus, it discusses the physiological basis for its uptake, hypotheses to justify its increase in the myocardium affected by anthracyclines, importance of ¹⁸F-FDG PET/CT findings for cardio-oncology, and primary challenges of incorporating this technique in standard clinical oncology practice.