Long-term hormone use doesn’t reduce heart attack risks in postmenopausal women with heart disease and may increase their chances of developing blood clots and gallbladder disease, new research suggests.

The findings in Wednesday’s Journal of the American Medical Association add to mounting evidence questioning doctors’ long-standing belief that hormone supplements benefit the heart by mimicking the effects of natural estrogen, which helps keep cholesterol at healthy levels.

The new research provides follow-up data on a study that was among the first to challenge that belief.

The original data showed that heart patients followed for an average of about four years had more heart attacks in the first year on hormone treatment, but fewer in subsequent years. The trend suggested that benefits might occur only after long-term use.

Wyeth Pharmaceuticals, which makes the estrogen-progestin supplement Prempro used in the research, paid for the follow-up study.

But the researchers found no such benefit after tracking many of the same 2,763 women for nearly three more years. During the follow-up, there were 111 heart events, including fatal and nonfatal heart attacks, in women on hormones and in those taking dummy supplements.

However, the blood clot rate was twice as high in the hormone group over the entire 6.8 years of study, with most of the risk occurring in the first few years. The rate of gallbladder disease requiring surgery was nearly 50 percent higher, bolstering evidence linking these conditions to hormone use.

The results suggest that women with heart disease should not take hormone supplements, said co-researcher Dr. Deborah Grady of the University of California at San Francisco

Grady said evidence that risks outweigh the benefits is strong enough to suggest that even women without heart disease should avoid supplement use except on a short-term basis to relieve hot flashes and other menopause symptoms.

“They’re still the best thing around for symptoms,” she said.

Wyeth said the study applies only to a narrow group of women, noting that most menopausal women don’t have heart disease and that the average age of women in the follow-up was 71, while the average age of menopause is 51.

The company’s Dr. Victoria Kusiak said the results support American Heart Association recommendations last year advising menopausal women against using hormones solely to prevent heart disease and strokes because of mounting negative evidence.

The study prompted a statement from the American College of Obstetricians and Gynecologists, saying, “whether hormone replacement therapy helps prevent heart disease in women who don’t already have the disease remains an open question.”

Information on the effects of hormones in healthy postmenopausal women is expected to come in 2005 from the Women’s Health Initiative, a large national study comparing results from women taking hormones for 12 years with those on placebo pills.