Cardiotoxicity of Aromatase Inhibitors in Breast Cancer Patients

Aromatase inhibitors represent an effective endocrine treatment for patients with hormone receptor-positive breast cancer, in early stage and in metastatic disease. However, by decreasing levels of serum estrogens they also potentially reduce the protective effect of estrogens on the cardiovascular system. Patients treated with aromatase inhibitors, in fact, compared with those who receive tamoxifen, more often develop hyperlipidemia, hypercholesterolemia, and hypertension, which are recognized risk factors for cardiovascular disease. This might raise some concerns especially in the adjuvant setting where the aim of treatment is the cure, and for postmenopausal patients who are already at risk for cardiovascular disease. However, whether the relative higher incidence of cardiac adverse events reported with aromatase inhibitors compared with tamoxifen is related to an actual cardiac toxicity of aromatase inhibitors rather than a cardioprotective effect of tamoxifen is still unclear. In this article we review the available literature on cardiotoxicity of aromatase inhibitors and provide some practical advice to improve the cardiovascular safety profile of these drugs.