CYP19A1 and ischemic stroke: Overall, 182 and 163 hospitalizations for ischemic strokes were observed among PS matched women who respectively started with aromatase inhibitors and tamoxifen, the corresponding incidence rates being 3.43 (2.93 to 3.93) and 3.00 (2.54 to 3.46) events every 1000 person-year (p = 0.106) (Table 2).