my personal edition > hrt > news


  E-Mail this DGDispatch to a colleague

DGDispatch

Hormone Replacement Therapy May Carry Greater Risk of Stroke for Some Women: Presented at NAMS

By John Otrompke

SAN DIEGO -- October 5, 2009 -- The continuing existence of a heart condition that exists in fetuses may make some women at greater risk for stroke if they use hormone replacement therapy, according to a study presented here at the 20th Annual Meeting of the North American Menopause Society (NAMS).

The condition, known as a foramen ovale, is a tunnel that serves the function of allowing oxygenated blood from a mother to a fetus without being sent to the fetus' lungs, but it usually closes in babies within a year of birth.

"However, if you cough, sneeze, or have a bowel movement, the pressure in some people may allow that passage to reopen between the right and left ventricle of the heart," said Nancy C. Greep, MD, Endocrine/Bone Disease Program, John Wayne Cancer Institute at Saint John's Health Center, Santa Monica, California, on October 2 during an oral presentation.

The condition may explain why hormone replacement therapy has been associated with an increased risk of stroke. According to the studies of the Women's Health Initiative, between 1993 and 2004, women on oestrogen are at a 55% greater risk for ischaemic stroke than at baseline, Dr. Greep said.

The current study was a retrospective analysis based on the University of California, Los Angeles stroke database covering 975 women admitted from 1993 to 2007. Researchers identified 127 postmenopausal women, and performed a shunt study if it had not already been performed.

Among premenopausal women with an ischaemic stroke, with a mean age of 72, a cause could be identified in 68%, but in 32% of the women (41/127), the stroke was cryptogenic.

A shunt was present in only 19% of women with stroke of known cause, but in 56% of those with cryptogenic stroke. Overall, about 20%, or 25 out of 127, of women with an ischaemic stroke were on HRT. Among women with a cryptogenic stroke, the proportion of HRT users in those with a shunt was 35% (8/23) versus 6% (1/18) in those without a patent foramen ovale.

The findings are significant, according to Dr. Greep, because the lifetime risk of stroke for women is 1 in 5, and 45% of ischaemic strokes are of unknown cause. "Ten percent of the time women with a stroke will die within a month of the event," Dr. Greep added.

"It might make sense to do a transcranial Doppler before prescribing oral hormones, and if they have a hole in the heart, tell them that oral HRT is riskier for them," Dr. Greep said. "It is possible to close the hole. Now, you don't need open-heart surgery, because the hole can be closed by inserting a catheter through the artery and inserting a little button," she explained.

[Presentation title: The Role of Patent Foramen Ovale (PFO) in Ischemic Strokes Among Postmenopausal Women on Hormone Replacement (HRT). Abstract S-4]

E-Mail this DGDispatch to a colleague

To print, use this version