Surprisingly, it appears to be OK.
Hulley et al. Randomized trial of estrogen plus progestin for secondary prevention of coronary heart disease in postmenopausal women. JAMA 1998; 280: 605 – 13, and follow-up Grady et al, Cardiovascular disease outcomes during 6.8 years of hormone therapy: heart and estrogen/progestin replacement study follow up (HERS II). JAMA 2002; 288: 49 – 57.
Clarke et al. A study of hormone replacement therapy in postmenopausal women with ischaemic heart disease: the Papworth HRT atherosclerosis study. BJOG 2002; 109: 1056 – 62.
Cherry et al. Oestrogen therapy for prevention of reinfarction in postmenopausal women: a randomised placebo controlled trial. Lancet 2002; 360: 2001 – 8.
(BMJ Learning module – Secondary prevention of ischaemic cardiac events.)