OBJECTIVE - Surgical menopause has been associated with an increased risk of coronary heart disease events. In this study, we aimed to determine the associations between coronary artery calcium (CAC) and hysterectomy, oophorectomy, and hormone therapy use with a focus on the duration of menopause for which there was no hormone therapy use.
DESIGN - In a substudy of the Women's Health Initiative placebo-controlled trial of conjugated equine estrogens (0.625 mg/d), we measured CAC by computed tomography 1.3 years after the trial was stopped. Participants included 1,064 women with previous hysterectomy, aged 50 to 59 years at baseline. The mean trial period was 7.4 years. Imaging was performed at a mean of 1.3 years after the trial was stopped.
RESULTS - Mean age was 55.1 years at randomization and 64.8 years at CAC measurement. In the overall cohort, there were no significant associations between bilateral oophorectomy, years since hysterectomy, years since hysterectomy without taking hormone therapy (HT), years since bilateral oophorectomy, and years of HT use before Women's Health Initiative enrollment and the presence of CAC. However, there was a significant interaction between bilateral oophorectomy and prerandomization HT use for the presence of any CAC (P = 0.05). When multivariable analyses were restricted to women who reported no previous HT use, those with bilateral oophorectomy had an odds ratio of 2.0 (95% CI: 1.2-3.4) for any CAC compared with women with no history of oophorectomy, whereas among women with unilateral or partial oophorectomy, the odds of any CAC was 1.7 (95% CI: 1.0-2.8). Among women with bilateral oophorectomy, HT use within 5 years of oophorectomy was associated with a lower prevalence of CAC.
CONCLUSIONS - Among women with previous hysterectomy, subclinical coronary artery disease was more prevalent among those with oophorectomy and no prerandomization HT use, independent of traditional cardiovascular disease risk factors. The results suggest that factors related to oophorectomy and the absence of estrogen treatment in oophorectomized women may be related to coronary heart disease.