More women die after heart surgery

Survival rates for men and women are equal in the UK

Women are up to three times more likely to die during or shortly after heart bypass surgery than men, a study reveals.

The younger the patients, the greater the mortality difference between the sexes, scientists suggest in the Journal of the American Heart Association.

The findings follow studies which show women who have heart attacks have a higher in-hospital death rate than men, especially among those under the age of 60.

Other studies suggest women undergoing heart surgery have a higher risk than men of suffering a stroke shortly after the operation.

In the UK there is very little difference in death rates between genders

Sir Charles George, British Heart Foundation

Coronary artery bypass surgery uses blood vessels to re-route blood flow around arterial blockages to improve the supply of blood and oxygen to the heart.

Heart surgeons perform about 571,000 bypass operations every year in the USA, including about 182,000 in women.

The team at Emory University of Atlanta, which carried out the research, were unable to determine why death rates were different between the sexes.

Dr Viola Vaccarino, who led the team, said the explanation might be some unknown factor that increases the risk for women who have bypass surgery, or something in the surgical procedure itself that might be subject to change.

The researchers reviewed records of 51,187 patients who received bypass surgery between October 1993 and December 1999.

Of these patients, 15,178 were women.

Overall, 5.3% of the women died in the hospital, compared with 2.9% of the men.

When broken down, statistics showed 3.4% of women younger than 50 died, compared with 1.1% of men.

In the 50-59 age group, women had an 86% higher risk of in-hospital death than men.

Further investigation

Dr Vaccarino said: "Women tended to have more pre-existing illnesses and risk factors in their medical history, but they had less extensive coronary atherosclerosis (progressive narrowing and hardening of the arteries) and their hearts had better pump function."

Scientists thought diabetes may be to blame for the higher death rates among women - diabetes was twice as common in women among patients younger than 50.

However additional ailments and heart disease risk factors accounted for less than 30% of the mortality differences between young men and women.

The British Heart Foundation says Britain does not replicate the findings of the US survey.

Medical Director at The British Heart Foundation Professor Sir Charles George said: "This American study raises concerns, however UK statistics don't show the same results.

"In the UK there is very little difference in death rates between genders.

"For both men and women, coronary artery bypass graft (CABG) surgery remains a relatively low-risk operation with high survival rates, in fact for men and women under 60 the survival rate is 97-98%.

"The US figures show that three times as many men having CABG operations as women.

"The women who have a CABG are also more likely to have other illnesses such as diabetes and kidney failure, which may complicate the procedure and increase the risks."

The US team says further investigation is necessary to determine the causes of the mortality differences.