Latent atherosclerosis as a risk factor in chemotherapy-induced cardiomyopathy.

Abstract

e12525 Background: Anthracyclines and monoclonal antibodies targeting HER2/neu receptors are widely used antineoplastic agents in breast cancer treatment. Both therapies have been known to cause cardiovascular adverse effects, notably chemotherapy-induced congestive heart failure, especially if used in combination. Multiple factors have been postulated to increase the risk of doxorubicin and trastuzumab-associated cardiotoxicity, including a pre-existing coronary artery disease, but the role of latent atherosclerosis has not been widely studied. Methods: We retrospectively reviewed health records of female breast cancer patients at our institution treated with doxorubicin or trastuzumab between 2012 and 2017. Using echocardiography, we identified patients with underlying atherosclerotic lesions at the start of the treatment and those who subsequently developed cardiotoxicity. Chemotherapy-induced cardiomyopathy was defined as a drop in the ejection fraction (EF) to < 50% from the normal EF of > 53% pre-therapy. We used a χ2 test to search for the relationship between atherosclerosis and subsequent cardiotoxicity. Results: A total of 518 patient records were reviewed. Of 518 patients with breast cancer, 93 (18%) received doxorubicin or trastuzumab-based chemotherapy. The median age for breast cancer diagnosis was 58. Sixty-one patients (66%) were identified to have atherosclerosis on echocardiography at the time of the first chemotherapy cycle. The most common location for atherosclerotic lesions was in the aortic arch and proximal upper abdominal aorta. Of 61 patients with atherosclerosis, ten (16.4%) subsequently developed chemotherapy-induced cardiomyopathy (p = 0.77). A post hoc analysis was performed to compare the two cohorts aged 40 to 50 (p = 0.49) and 51 to 75 (p = 1.00) as they represented the majority of breast cancer cases. Conclusions: The role of atherosclerosis in doxorubicin and trastuzumab-induced toxicity remains unclear. We did not observe any statistical correlation between atherosclerosis at the start of chemotherapy and increased rates of cardiac injury. A younger population may be more susceptible to cardiotoxicity, but further research is needed as the study has limitations. Although we identified patients with latent atherosclerosis, additional evaluation via carotid artery intima-media thickness measurements would yield more precision. Other methods such as the use of computed tomography and coronary artery calcium scores would also allow for assessing atherosclerotic plaque burden. Still, not all patients were subjected to these techniques. Furthermore, the study was challenged by the small sample size and its retrospective nature. Larger prospective studies are essential to explore this area further. Identifying the means of reducing cardiovascular complications remains a priority as heart disease is currently the leading cause of death among breast cancer survivors.