The purpose of this program is to assess whether hormonal replacement therapy and/or antioxidant treatment will stabilize or inhibit progression, and induce regression of coronary plaques in women. Phase 1(8 months) comprises planning and organizing the Study Protocols, Manual of Operations, and data forms. Protocol Development will take approximately 6 months. After Protocol Development, there will be an approximate 2 month hiatus in activity on the study. During this time, the participating centers will prepare and submit revised cost proposals based on the actual protocol. Phase 11(4 years) will be for patient recruitment and patient follow-up. Phase 111(6 months) is for data analysis.