Decline in Heart Disease Deaths in Women Leveling Off

By Todd Neale
OXFORD, England, 05 may 2008 -- The rate of decline in coronary heart disease mortality is slowing considerably for women younger than 50, according to trends reported by researchers here.
After a steep drop in the rate of coronary disease mortality for women younger than 50 in England and Wales starting 30 years ago, the new trends indicate a grimmer picture.
They indicate trends toward "a future plateau and possible reversal of previous improvement," Steven Allender, Ph.D., of the University of Oxford, and colleagues reported online in BMC Public Health.
From 1986-1995 to 1996-2005, the coronary heart disease mortality rate in England and Wales dropped by 19.5%, half the rate of decline from the previous decade, they found. The rate had dropped by 40.4% from 1976-1985 to 1986-1995.
The rate of decline in coronary heart disease mortality rate also slowed for men younger than 50 -- falling from 41.5% to 34.6% -- but has been steady since 1990.
On the other hand, although the actual burden of coronary heart disease deaths remains greatest in patients ages 50 to 69, the rate of decline has accelerated for men and women in this age group. For men, the coronary heart disease mortality rate fell by 23.9% from 1976-1985 to 1986-1995 and by 45.1% from the latter time period to 1996-2005.
For older women, the corresponding changes were 19.7% and 46.1%.
Overall rates of death from coronary heart disease increased steadily in both men and women in England and Wales until the mid-1970s when the rates began to fall, the researchers said.
Studies on long-term trends in coronary heart disease mortality rates stratified by age group are important, the researchers said, because, "when only age-standardized rates are considered, reductions in the mortality rate in older age groups may obscure less positive trends in younger men and women."
They noted that the rising prevalence of cardiovascular risk factors such as obesity, diabetes, smoking, and physical inactivity among the younger population could begin to slow or reverse the rate of decline of deaths from coronary heart disease.
Indeed, a U.S. study last year found that the rate of decline had completely reversed and had begun increasing in women ages 35 to 44 and had slowed considerably in men ages 35 to 54.
o explore these trends in England and Wales, Dr. Allender and colleagues examined mortality data in 10-year birth cohorts from the 1930s through 2005.
In both genders and all age groups up to age 69, coronary heart disease deaths and mortality rates increased from 1936 until the mid-1970s, after which they started to decline. Overall, from 1936-1945 to 1966-1975, the rate increased by 287% in men and by 264% in women.
From 1976-1985 to 1996-2005, the coronary heart disease mortality rate dropped by 58.5% in men and by 56.5% in women.
The trend for older age groups to have a higher burden of coronary heart disease has been established in women much longer than in men, the researchers said. For example, the number of coronary heart disease deaths in women ages 80 to 84 exceeded those in women ages 60 to 64 for the first time in 1949. That did not happen in men until 1985.
The researchers noted that the pattern of an accelerating rate of decline in coronary heart disease mortality in older patients and a slowing rate of decline in younger patients suggested that advances are disproportionately being made in the older population.
"There are a number of reasons for this," they said, "including the targeting and efficacy of screening, the inclusion criteria for beginning of treatment regimes (which include age as a standard risk factor), and the current public health focus on mortality reduction in older populations."
The authors noted that the study was limited by the fact that the definition of coronary heart disease has changed slightly over time. Consequently, all comparisons between age cohorts should be interpreted cautiously, they said.
Methods of death certification have also changed over time, they said.
The authors declared that they have no conflicts of interest.

Primary source: BMC Public HealthSource reference:Allender S, et al "Patterns of coronary heart disease mortality over the 20th century in England and Wales: Possible plateaus in the rate of decline" BMC Public Health 2008; DOI: 10.1186/1471-2458-8-148.