A study of hormone replacement therapy in postmenopausal women with ischaemic heart disease: the Papworth HRT Atherosclerosis Study

OBJECTIVE: To assess the possible benefit of hormone replacement therapy (HRT) in the secondary prevention of ischaemic heart disease. DESIGN: A prospective randomised trial of transdermal HRT in women with definite ischaemic heart disease. SETTING: A regional cardiac unit. POPULATION: Postmenopausal women with angiographically proven ischaemic heart disease. METHODS: A total of 255 postmenopausal women with angiographically proven ischaemic heart disease were recruited and randomised; 134 were treated with transdermal HRT and 121 acted as controls. The women were seen at six monthly intervals. The primary end points, which were determined by a blinded assessor, were admission to hospital with unstable angina, proven myocardial infarction or cardiac death. A total of 53 (40%) patients withdrew from the HRT group and eight (7%) from the control group. The mean duration of follow up was 30.8 months. MAIN OUTCOME MEASURES: Admission to hospital with unstable angina, proven myocardial infarction or cardiac death. RESULTS: During follow up, there were 53 primary end-point events in the HRT group and 37 in the control group. Using an intention-to-treat analysis, the primary end-point event rate was 15.4 events per 100 patient years for the HRT group compared with 11.9 for the control group (event rate ratio 1.29 (95% CI 0.84-1.95, P = 0.24)). Using a per-protocol analysis, there was an event rate ratio of 1.49 (0.93-2.36, P = 0.11) for the HRT arm compared with the control arm. Particularly during the first two years of follow up, the HRT group had a higher, but not statistically significant, event rate than the control group. CONCLUSION: Our findings suggest that transdermal HRT should not be commenced for the purpose of secondary prevention in postmenopausal women with angiographically proven ischaemic heart disease.