Lack of effect of HRT on stroke/TIA risk 'not surprising'
- Joanna Lyford1
© Biomed Central Ltd 2001
Received: 14 March 2001
Published: 18 October 2001
KeywordsCerebrovascular disorders, hormones, stroke
A study was undertaken to determine whether Hormone replacement therapy (HRT) increases the risk of stroke or transient ischaemic attack (TIA) among postmenopausal women with established heart disease.
Approximately 5% of the group, had 165 strokes, of which 85% were ischemic, resulting in 26 deaths. There was no significant association between HRT and nonfatal stroke, fatal stroke, or TIA, with approximately 7% of women on HRT suffering a nonfatal or fatal stroke, compared with 5% on placebo. Researchers noted that independent predictors of stroke events included increasing age, hypertension, diabetes, current cigarette smoking, and atrial fibrillation. However, a 4% decrease in stroke risk for each unit increase in BMI was observed.
The authors concluded that these findings may have occurred by chance or may possibly reflect residual confounding by other risk factors, such as smoking. The authors of an accompanying editorial (see Additional information) questioned whether the results were unexpected. They suggested that it was not surprising that HRT was not protective against stroke in a cohort of elderly women (average age, 67 years) who were many years postmenopausal and had established CHD. They pointed out, however, that HRT might not show these limitations in younger, presumably healthy women, for the primary prevention of cardiovascular disease. This role is currently being investigated by trials such as the Women's Health Initiative.
At total of 2763 women were randomly assigned conjugated to receive either equine estrogen or placebo. The primary clinical endpoints were stroke incidence and stroke death over a mean follow-up of 4.1 years.