Women benefit just about as much as men from cardiac catheterization after having a heart attack, according to a study published on Tuesday, contradicting previous indications that the procedure may not help women.

But the researchers said their findings showed that routinely performing a cardiac catheterization may not benefit women who have not had a heart attack but have unstable angina, a kind of acute chest pain that can be a warning sign for a future heart attack.

Cardiac catheterization is a procedure that enables doctors to locate and open possible coronary artery blockages with the aim of preventing heart attacks and death.

The procedure involves passing a long, thin, flexible tube known as a catheter typically through the upper thigh and into the heart, allowing doctors to do diagnostic cardiac tests and treatments.

In the United States, cardiac catheterization is routinely performed on most patients who come to a hospital with a heart attack or unstable angina. But previous research had suggested women may not benefit as much as men from the procedure or even might be harmed.

“Although heart disease is the No. 1 killer of women each year, there still remain a lot of unanswered questions about the best way to treat women with heart disease,” Dr. Michelle O’Donoghue of Brigham and Women’s Hospital and Massachusetts General Hospital in Boston said in a telephone interview.

“And this is in part due to the fact that men continue to outnumber women in randomized clinical trials (assessing cardiac care). So, therefore, in a lot of instances, we don’t really know whether women benefit as much as men from some of our proven therapies,” added O’Donoghue, who led the study published in the Journal of the American Medical Association.

To clarify the issue, the researchers combined data from eight previously conducted clinical trials that involved more than 10,000 people who had suffered a heart attack or unstable angina, and assessed differences among men and women.

They compared patients who had undergone invasive treatment involving routine cardiac catheterization to those who had undergone a conservative treatment strategy relying on drugs in which cardiac catheterization generally was not used.

They found that men and women who had a heart attack got a similar level of benefit from routine cardiac catheterization compared to those with the more conservative treatment. The men had a 44 percent reduction in risk of death, another heart attack or rehospitalization. Women had a 33 percent reduction.

The story was different for those who did not have a heart attack but had unstable angina. The men experienced a modest benefit, but the women got no benefit. The researchers even saw increases in the risk of death or heart attack for these women, but these risks were not statistically significant.

She suggested it might be best for women who do not have a heart attack to get the more conservative treatment approach in which they undergo a catheterization only if they have ongoing cardiac symptoms or a positive stress test.

By Will Dunham
WASHINGTON (Reuters)