558 Background: Data show that in post-menopausal women with early breast cancer, longer use of aromatase inhibitor (AI) is associated with increased odds of ischemic heart disease. Here we explore the association between adjuvant AI use and cardiac disease in women undergoing cardiac angiography after a diagnosis of early breast cancer. Methods: We linked a database of 7,681 women who underwent cardiac angiography at the University Clinical Center of Ljubljana between December 2004 and November 2010 with the Cancer Registry for Slovenia. Women with early breast cancer that subsequently underwent cardiac angiography were identified. Information on cardiovascular risk factors was retrieved from the patients’ charts and from discharge letters after cardiac angiography. The endpoint of interest was a diagnosis of ischemic heart disease or left ventricular dysfunction (IHD-LVD) without evidence of valvular heart disease at the time of angiography. Conditional, logistic regression was used to test for associations between variables. Results: Among 117 eligible women 75% (n=88) were postmenopausal and 62% (n=73) had hormonal receptor positive (HR+) disease. Of these 42% (n=31) were treated with AI. Overall, 48% (n=56) of women were found to have IHD-LVD. In patients with HR+ breast cancer, use of AIs was significantly associated with IHD-LVD as compared to tamoxifen alone (HR 2.50, 95% CI 1.01-6.29, p=0.046). For each year of AI therapy, there was a trend for higher odds of IHD-LVD (OR: 1.25, 95% CI 0.95-1.67, p=0.116). This effect appeared independent of age, body mass index, baseline hypertension, hypercholesterolemia, diabetes and heart disease or prior anthracyclines exposure. Among all patients, use of anthracyclines and left-sided irradiation was associated with non-significant increases in IHD-LVD (HR 2.37, 95% CI 0.89-6.09, p=0.45 and HR 1.28, 95% CI 0.69-2.40, p=0.44 respectively). Conclusions: Compared to tamoxifen, AIs are associated with a time dependent increase in IHD-LVD. This risk appears independent of other risk factors for heart disease. Anthracycline exposure and left breast or chest wall radiation showed non-significant associations with IHD-LVD in this small cohort.
Radiation-Induced Ischemic Heart Disease in Breast Cancer: A Review
