HRT for 10 years appears to cut risk of heart failure and heart attack without increasing cancer, deep venous thrombosis or stroke

Women who take hormone replacement therapy (HRT) for 10 years after menopause may have a significantly reduced risk of mortality, heart failure and heart attack without any increased risk of cancer, deep venous thrombosis or stroke, a study found.

Danish researchers carried out a randomized trial over 10 years with six years of additional follow-up on 1,006 white, healthy, recently menopausal women age 45 to 58. In the study, 504 received hormone replacement therapy and 502 didn't. Results appeared Oct. 9 at BMJ.

After 10 years, 16 women in the treatment group had either died of or were hospitalized for a heart attack or experienced heart failure, compared to 33 in the control group (hazard ratio [HR], 0.48; 95% CI, 0.26 to 0.87; P=0.015). Deaths were 15 in the treatment group compared with 26 in the control group (HR, 0.57; 95% CI, 0.30 to 1.08; P=0.084).

There was no increase in any cancer (36 in the treated group vs. 39 in the control group; HR, 0.92; 95% CI, 0.58 to 1.45; P=0.71) or breast cancer (10 in the treated group vs. 17 in the control group; HR, 0.58; 95% CI, 0.27 to 1.27; P=0.17) associated with HRT. This effect lasted for the 16 years of treatment and follow-up.

There were two cases of deep venous thrombosis in the treated group versus one in the control group (HR, 2.01; 95% CI, 0.18 to 22.16). There were 11 strokes in the treatment group compared to 14 in the control group (HR, 0.77; 95% CI, 0.35 to 1.70).

Researchers wrote, “With the longest duration of randomized treatment and complete and long-term follow up, the present study provides a unique opportunity to study the clinical implications of long term hormone therapy started in young postmenopausal women within three to 24 months of menopause when randomized.”