ABC | Volume 114, Nº6, June 2020

Short Editorial Evaluating the Severity of Coronary Artery Disease in Patients Treated with Chemotherapy: The Further Need for Cardio-Oncology Matthew E. Harinstein 1 Heart and Vascular Institute, University of Pittsburgh Medical Center, 1 Pittsburgh, PA -USA Short Editorial related to the article: Chemotherapy-Related Anatomical Coronary-Artery Disease in Lung Cancer Patients Evaluated by Coronary- Angiography SYNTAX Score Mailing Address: Matthew E. Harinstein • UPMC Heart and Vascular Institute - South Tower 3F, E352.2, 200 Lothrop Street Pittsburgh, PA 15213 E-mail: harinsteinme@upmc.edu Keywords Coronary Artery Disease/radiotherapy; Neoplasms; Cardiotoxicity; Survival Rate; Myocardial Infarction/ complications; Thromboses/complications. Cardiovascular toxicity related to cancer therapies has been recognized for years. 1 The number and types of toxicities have increased rapidly due to several factors including new and improved therapies and treatment regimens which have resulted in patients living longer. This is the basis for the burgeoning field of cardio-oncology to help identify cardiotoxicities and aim to minimize adverse outcomes. Cardiomyopathies related to anthracyclines, which are typically irreversible, and trastuzumab, typically reversible, as well as more recently recognized cardiotoxicities including myocarditis related to immune checkpoint inhibitors have made the evaluation of concomitant cardiac disease critical in the care of patients being treated for cancer. 1,2 Coronary artery disease (CAD) is also a consequence of cancer therapies and adverse coronary events such as myocardial infarction and thrombosis can complicate treatment and result in poor outcomes. Thus, further understanding of the adverse effects of specific therapies is crucial to assessing patients’ clinical statuses and making decisions on treatment strategies in order to maximize overall outcomes, both oncologic and cardiac. CAD and has been associated with radiation therapy. 3,4 The risk and anatomic severity of CAD related to radiotherapy treatment has been described. 5,6 In a study of 152 thoracic cancer survivors who underwent radiotherapy, the investigators observed that the study patients had higher SYNTAX scores and were at a higher risk of developing anatomically severe CAD, independent of chemotherapy. 6 While although CAD is known to be present in patients being treated with chemotherapy, independent of radiotherapy, the association between anatomic severity of CAD and chemotherapy is less well known. Acute coronary syndromes, including coronary thrombosis, myocardial infarction, angina as well as vasospasm are known to be complications of several chemotherapy agents, which affects both short and long-term outcomes. 7 Traditional cardiovascular risk factors including hypertension, diabetes mellitus and tobacco abuse are present in patients with cancer and it has been suggested that pre-existing CAD increases the risk of developing treatment-related CAD. 8 Despite the effectiveness of chemotherapeutic agents against cancer, potential mechanisms leading to unintended cardiovascular events include endothelial dysfunction, platelet aggregation, reduced nitrous oxide levels, increased levels of reactive oxygen species and vasospasm. 9 However, the effect that different chemotherapy agents have in regards to the anatomic severity and complexity of CADmay further help to risk stratify patients undergoing chemotherapy in order to determine who may be at risk of adverse cardiac events and or who should have alterations in their treatment considered. In this issue of Arquivos Brasileiros de Cardiologia , Yang et al. 10 investigated the association between chemotherapy and atherosclerotic anatomic abnormalities of coronary arteries, based on coronary angiography, in patients treated for lung cancer. 10 Their retrospective cross-sectional study group included 94 patients, 36 of whom received chemotherapy and the remaining did not. It should be noted that nearly half of those who received chemotherapy also had radiation therapy, whereas only 7% of those who did not have chemotherapy had radiation. The authors found that the severity of CAD, as assessed by the SYNTAX score, was higher in the chemotherapy group compared to the non-chemotherapy group. After univariate and multivariate analyses, they determined that chemotherapy increased the risk of a high SYNTAX score and chemotherapy increased the risk of more severe anatomical CAD by 5.323 times. Patients in the cohort exhibited traditional CAD risk factors including older age, hypertension and tobacco abuse, however, only half smoked and approximately 20% had diabetes mellitus. There were no significant demographic differences between the chemotherapy and non-chemotherapy groups. Importantly, the authors reported the types of chemotherapy regimens the patients received. Platinum-based chemotherapies have been associated with up to a 1.5- to 7-fold higher long-term risk of CAD and myocardial infarction, however, the complexity of CAD is not well described. 7 In the population studied by Yang et al. 10 approximately 78% of patients were treated with platinum- based regimens. They observed an even greater risk of more severe anatomical CAD in this group. The authors conclude that chemotherapy is associated with anatomical complexity and severity of CAD and postulate that it might partly account for the higher risk of CAD among lung cancer patients. It is important to note that while although medical management should be the first treatment strategy employed for the treatment of CAD, invasive therapies are not prohibitive despite the presence of several comorbidities. DOI: https://doi.org/10.36660/abc.20200408 1013