Sex differences narrow in death after heart attack

In recent years, women, particularly younger women, experienced larger improvements in hospital mortality after myocardial infarction than men, according to a new study.

Over the last decade some studies showed that younger women, but not older ones, are more likely to die in the hospital after MI than age-matched men. A team of researchers led by Emory University examined whether such mortality differences have declined in recent years.

"We found that the number of younger women who die in the hospital after a heart attack, compared with men has narrowed over the last few years," says study leader Viola Vaccarino, MD, PhD, professor of medicine (cardiology), Emory University School of Medicine.

Vaccarino says changes in patient characteristics and treatments over time accounted in part for the changing mortality trends. The findings were presented Nov. 12 at the American Heart Association Scientific Sessions conference in New Orleans.

Often referred to as a heart attack, MI occurs when the blood supply to part of the heart is interrupted. This decreased blood supply is commonly due to blockage of a coronary artery and if left untreated can cause damage and/or death (infarction) of heart muscle tissue.

The researchers investigated MI mortality trends according to sex and age in five age groups during a 12-year period from 1994 to 2006. The study population included 916,380 MI patients from the National Registry of Myocardial Infarction (NRMI) who had a confirmed diagnosis of MI.

The researchers found that hospital mortality declined markedly between 1994 and 2006 in all patients, but more so in women than in men in virtually every age group. The mortality reduction in 2006 relative to 1994 was largest in women under the age of 55 years (53 percent) and lowest in men under the age of 55 years (33 percent). In patients younger than 55, the absolute decline in mortality was three times larger in women than in men (2.7 percent vs 0.9 percent).

The sex difference in mortality decline became progressively lower in older patients. As a result, the death rate in younger women, compared with men was less pronounced in 2004-06 than in 1994-95.