CYP19A1 and breast cancer: A number of studies have suggested that aromatase inhibitors may increase the HF risk.29, 30 Haque et al. 29 studied CVD outcomes in over 13 000 post‐menopausal BC patients and found a higher HF risk in patients treated with aromatase inhibitors compared to patients treated with tamoxifen only (hazard ratios 1.1–1.3).