Heart attacks appear to have become more common in middle-aged women over the
past two decades, but all women and especially those younger than 55 have
recently experienced a greater increase than men in their chances of survival
following such a heart event, according to two reports in the 26 October issue
of Archives of Internal Medicine, one of the JAMA/Archives journals.
Middle-aged women have historically had a lower overall risk of heart events and
stroke than men of a similar age, according to background information in one of
the articles. However, a recent report showing higher stroke rates among women
than men in a sample representative of the US population appeared to reveal a
new phenomenon and raised the question of whether heart disease or heart attack
were also becoming more prevalent among women.
Amytis Towfighi, MD, of the University of Southern California, Los Angeles, and
colleagues analyzed data from US adults age 35 to 54 who participated in the
National Health and Nutrition Examination Surveys (nationally representative
surveys conducted by the government) during 1988 to 1994 (4,326 participants)
and 1999 to 2004 (4,075 participants). The researchers assessed how often men
and women had heart attacks and also compared their Framingham coronary risk
score, a measurement of heart disease risk over 10 years that includes factors
such as age, cholesterol levels, blood pressure and smoking history.
In
both study periods, men age 35 to 54 years had more heart attacks than women in
the same age group. However, the gap narrowed in more recent years as heart
attacks decreased in prevalence among men and increased in prevalence among
women (2.5 percent of men and 0.7 percent of women reported a history of heart
attack in 1988-1994, whereas 2.2 percent of men and 1 percent of women did so in
1999-2004).
Between the two time periods, the average Framingham coronary risk score showed
an improving trend among men but decreased among women. In male participants,
total cholesterol levels remained stable, high-density lipoprotein (HDL or
"good" cholesterol) levels and systolic (top number) blood pressure levels
improved and smoking levels declined. The only risk factor that improved among
women was HDL levels. Diabetes prevalence increased among both men and women,
likely due to insulin resistance and the obesity epidemic in both sexes.
"Although men in their midlife years continue to have a higher prevalence of
myocardial infarction and a higher 10-year risk of hard coronary heart disease
than women of similar age, our study suggests that the risk is increasing in
women, while decreasing in men," the authors write. "Therefore, intensification
of efforts at screening for and treating vascular risk factors in women in their
midlife years may be warranted."
In another report, Viola Vaccarino, MD, PhD, of Emory University School of
Medicine, Atlanta, and colleagues investigated trends in the rate of in-hospital
deaths following heart attack from June 1, 1994, through 31 December 2006. Data
were collected from 916,380 patients through the National Registry of Myocardial
Infarction.
In-hospital death rates decreased among all patients between 1994 and 2006, but
decreased more markedly in women than in men. The reduced risk of death was
largest in women younger than 55 years (a 52.9 percent reduction) and lowest in
men of the same age (33.3 percent). The absolute decrease in the risk of death
among patients younger than 55 was three times larger in women (2.7 percent)
than men (0.9 percent).
"A large part (93 percent) of this sharper decrease in mortality of younger
women compared with men in recent years was because the risk status of women on
admission improved compared with that of men," the authors write. "Such
improvement may be due to better recognition and management of coronary heart
disease and its risk factors in women before the acute myocardial infarction
event, as suggested by the narrowing sex difference in previous
revascularization [surgical treatment for heart disease]."
Source: JAMA/Archives: Archives of Internal Medicine: October 2009
