Numerous studies have shown that women are undertreated for heart disease. Doctors often fail to prescribe aspirin and drugs for high blood pressure or high cholesterol to women who suffer heart attacks, even though the medications have been shown to prevent further heart attacks.

During routine health-care visits, women also are less likely than men to be counseled regarding nutrition, physical activity and weight reduction.

A new study presented recently at the American Heart Association’s annual scientific sessions reveals one more instance of medical gender bias. Mayo Clinic doctors report that women with heart failure are less likely than men to receive a specialized pacemaker known to improve symptoms for people with heart failure.

Heart failure is the term used to describe a reduction in the heart’s ability to pump blood efficiently.

This pattern of gender bias occurs even though women who receive the implant live longer than men who get it.

The implant treatment studied is called cardiac resynchronization therapy, or C-R-T for short. It uses a specialized pacemaker to harmonize the contraction of the heart’s main pumping chambers, the right and left ventricles.

The scientists studied more than three-hundred-and-seventy heart-failure patients who’d received a C-R-T implant at Mayo Clinic between 1999 and 2004. Eighty-two percent were male, although the seventy-six percent survival rate for women after five years was almost double that of the men.

Researchers called for further studies to evaluate whether such gender-referral bias is universal.