HRT Not Linked to Cardiovascular Events in Women with AF

By Will Boggs MD

NEW YORK - Hormone replacement therapy (HRT) is not independently associated with death, stroke, thromboembolism or bleeding in women with atrial fibrillation (AF), according to data from the AFFIRM trial.

That means women with AF who have menopausal symptoms or associated osteoporosis "can use HRT without worrying about enhancing their stroke risk," Dr. Gregory Y. H. Lip from the University of Birmingham Centre for Cardiovascular Sciences in the UK told Reuters Health by email.

Women over 65 who have AF face a higher risk of stroke and thromboembolism than men, but it hasn't been clear whether HRT contributes to that risk, Dr. Lip and his colleagues write in Stroke, online September 4.

Using data from nearly 1,600 women in the AFFIRM trial, the team found that the primary composite endpoint of all-cause death, stroke, systemic/pulmonary embolism and myocardial infarction occurred more often among non-HRT-treated women than among the 376 women who had been on HRT at baseline (6.3 events vs. 4.2 events per 100 patient-years, p=0.002).

However, HRT was not associated with the primary endpoint or with any individual endpoint or net clinical benefit after adjusting for other risk factors.

Rates of warfarin anticoagulation did not differ according to HRT, the researchers note, although HRT users had a higher percent time in the therapeutic range than did non-HRT users (0.61 vs. 0.57).

Factors strongly correlated with the primary endpoint included age, diabetes, previous stroke, heart failure, and time in the therapeutic range.

"The only available prior data assessing HRT use on the risk of stroke in women with AF were from the Stroke Prevention in Atrial Fibrillation (SPAF) I-III trials, and that data included 90 women in the HRT group within a cohort of only 274 women," Dr. Lip said. "Thus, our much larger study gives stronger evidence that in female patients with AF, HRT did not predict the primary composite end point, nor all-cause death, ischemic stroke, or major bleeding."

Outside experts agreed HRT should not generally be avoided in women with AF out of fear of stroke.

"Too many women have suffered unnecessarily for the past decade due to unrealistic fear of HRT," Dr. Louise Schierbeck from Bispebjerg Hospital's Department of Cardiology in Copenhagen, Denmark, told Reuters Health by email.

Dr. Frederick Naftolin from New York University School of Medicine, who has researched various aspects of HRT, noted that the treatment may have a number of benefits, including fracture prevention and cardioprotection.

"The initial misapprehension of the results of the Women's Health Initiative (WHI) have been refuted by re-evaluation and later studies of the WHI and dozens of other studies," he told Reuters Health by email. "HRT offers little risk and much good to properly selected patients. Neither patients nor their caregivers should have more a priori concern of the use of HRT than of any other treatment. This study does not support an increased danger of stroke from HRT; however, it is a small study that addressed a very special population and was underpowered to show decreased hazard."

SOURCE: https://bit.ly/1qE7hFe

Stroke 2014.

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