Abstract 16970: Relation of Coronary Artery Calcification to Outcomes Among Women Ages 50-59 in the Women’s Health Initiative Estrogen-alone Clinical Trial
Introduction: In the Women’s Health Initiative (WHI) Estrogen-Alone (E-alone) clinical trial (CT), women aged 50-59 at entry randomized to E-alone had lower risk of myocardial infarction (MI) and mortality than women in the placebo group. The WHI Coronary Artery Calcification (CAC) Study enrolled 1064 women aged 50-59 and showed that CAC, measured by cardiac CT and Agatston scores, was significantly lower among those randomized to E-alone than in the . placebo group at ~8.7 years after randomization.
Hypothesis: We hypothesized that CAC scores would be related to risk of incident CVD, CHD and total mortality.
Methods: Over ~8 years of follow-up from the CAC scan through 2015, incident CHD (MI and fatal CHD), CVD (CHD, stroke, TIA, CHF, angina, coronary revascularization, carotid disease, peripheral vascular disease and CVD death) and total mortality were ascertained. Women with CVD prior to CAC scan (n=89) were excluded from the CVD and CHD analyses.
Results: Approximately 50% of the women had CAC=0, 27% had CAC=1-99, and 23% had CAC ≥ 100. The association between CAC and subsequent CHD, CVD, and mortality outcomes did not appreciably differ by randomized treatment arm. During follow-up, 17 CHD events, 62 CVD events, and 55 deaths occurred, of which 9 were due to CVD. CVD events included 15 MIs, 15 strokes, and 28 revascularizations, similarly distributed in E-alone and placebo. Age-adjusted CHD incidence rates were more than 7-fold higher for CAC ≥ 100 (6.87/1000 person-years (PY) than for no CAC (0.90/1000 PYs. Compared to a CAC score equal to zero, and adjusted for age, E-alone vs. placebo, smoking, diabetes, hypertension, and hypercholesterolemia, HRs (95%CI) for CHD were 2.67 (0.67-6.07) for women with CAC 1-100 and 7.88 (1.94-31.98), for CAC >100. The corresponding HRs for CVD were 1.65 (0.83-3.28) and 4.06 (2.11-7.80), respectively. The corresponding HRs for total mortality were 1.97 (0.93-4.16) and 2.87 (1.35-6.07), respectively, which were relatively unchanged with additional adjustment for baseline CVD.
Conclusions: Among women aged 50-59 in the WHI-CACS, extent of CAC was a major predictor of subsequent CHD, CVD and death.
Author Disclosures: I. Poornima: None. L.H. Kuller: None. M. Allison: None. J.E. Manson: None. M.J. LaMonte: None. J. Carr: None. Y. Chang: None. R.H. Mackey: None.
- © 2016 by American Heart Association, Inc.