March 8, 2012 -- Women with failing hearts survive longer than men, according to the largest analysis ever to examine the impact of gender on heart failure deaths.

When researchers analyzed data from 31 studies involving nearly 28,000 men and 14,000 women, they found male gender to be an independent risk factor for death from heart failure.

About 5.7 million Americans suffer from heart failure. Women tend to develop heart failure later in life than men, and there has been a suggestion that they also survive longer once they have it.

But because far fewer women than men have been enrolled in heart failure trials over the years, little else is known about the impact of gender on treatment and outcomes in heart failure patients.
Men, Women, and Heart Failure

In an attempt to remedy this, an international team of researchers examined three years of follow-up data on more than 40,000 heart failure patients in the study, published in the European Journal of Heart Failure.

The analysis revealed that:

    The overall death rate was similar for both genders, with about 1 in 4 patients dying during the follow-up.
    When the researchers took age into account, though, men had a 31% higher death risk than women, and male gender was an independent risk factor for death.
    Women with heart failure tended to be older than men (average age, 70 vs. 65) and they were more likely to have a history of high blood pressure (50% vs. 40%).

Heart failure occurs when the heart is unable to pump enough blood to meet the body’s demands.

Common symptoms include shortness of breath, swelling, and tiredness, primarily a result from failure of the left side of the heart, or ventricle, which pumps blood to the rest of the body.

The extent of failure to the left side of the heart is measured with a test known as “ejection fraction.”

A reduced ejection fraction means that the left side of the heart is not able to pump as forcefully as it should.

In the newly published analysis, reduced ejection fraction was associated with a higher risk of death, and men were more likely to have reduced ejection fraction than women (81% vs. 62%).
Women Prescribed Fewer Heart Failure Drugs

But the difference in ejection fraction did not fully explain the better survival among women, says researcher Manuel Martinez-Selles, MD, of Madrid’s Gregorio Maranon University Hospital.

The researchers concluded that more study is needed to understand why the risk of death from heart failure is lower among women than men.

Women enrolled in the trials were prescribed fewer standard treatments for heart failure than men, including ACE inhibitors, angiotensin receptor blockers, and beta blockers.

Cardiologist and heart failure researcher Ileana L. Pina, MD, of the Montefiore Medical Center in the Bronx, N.Y., says there has long been a critical need to enroll more women in heart failure trials, but she adds that the reason this has not happened is complex.

She says not as many women as men are asked to participate in such trials, and women may be less willing to participate when they are asked.

“We need a representative number of women to be included in heart failure trials, but that isn’t happening,” she says.