Two-decade decline: Rate of heart attack falls among black and white adults
|April 09, 2012|
The incidence of heart attack among blacks and whites has dropped significantly over the past two decades, according to a new study from the University of North Carolina at Chapel Hill.
The study, published online and scheduled to appear in the April 17 issue of Circulation, analyzed nearly 31,000 fatal and non-fatal heart attacks among 396,000 adults in four communities in the United States from 1987 to 2008. The individuals, black and white men and women, were ages 35 to 74. Using a specially-designed mathematical model, the research team accounted for changes in the clinical definition of heart attacks that have occurred over the past 22 years. Through those adjustments, the team identified the occurrence of heart attack is, in fact, declining.
“This study tells us a bit about whether the things we’re doing to prevent heart disease are having an impact in the community. It tells us about the role of prevention relative to the role of treatments in reducing death due to heart diseases,” said Wayne Rosamond, PhD, lead study author and epidemiology professor at UNC Gillings School of Global Public Health. “What the results say is it looks like the things that determine the incidence of disease, like prevention strategies, seem to be working. The next step is to understand which pieces of what we are doing have the strongest effect and then do more of it.”
Rosamond and his colleagues examined the rate of heart attack in these populations because no national data exist to study trends in the incidence of heart disease. This study used innovative statistical methods and was able to monitor population based trends in heart disease in diverse communities over a long period of time. The study, known as the Atherosclerosis Risk in Communities Study, included participants from Forsyth County, N.C.; Jackson, Miss.; eight northern suburbs of Minneapolis, Minn.; and Washington County, Md.
“It’s clear the things we do in medical care are still doing a good job of keeping people alive after a heart attack, but we’re now starting to see prevention kicking in,” said Rosamond, who is also adjunct professor of emergency medicine in the UNC School of Medicine. “This is the first time we’ve been able to see prevention playing a major role in the decline of coronary heart disease mortality.”
According to the results of the study, after adjusting for changing biomarkers of heart tissue damage and diagnostic advancements, researchers found the incidence rate of heart attack that resulted in a hospitalization fell 3.8 percent annually in men and 3.5 percent annually in women between 1987 and 2008. Among specific groups, the yearly declines were 4.3 percent among white men, 3.8 percent among white women, 2.9 percent among black women, and 1.5 percent among black men. This rate reflects the drop per 1,000 individuals, meaning there has been over a 60 percent drop in two decades.
The most significant declines in incidence occurred during the second half of the study – the decline from 1997 to 2008 was nearly double that of the previous decade, especially among blacks. This suggests an acceleration in the impact of heart disease prevention efforts over time.
The rate of deaths related to coronary heart disease among people with a history of heart attack also dropped. The death rate fell 4.7 percent among men each year and 4.3 percent among women. In addition, when adjusted for age, the fatality rate 28 days after a hospitalization decreased 4.2 percent in white men, 3.6 percent in black men, 2.6 percent in white women, and 2.4 percent in black women.
“The message here is that we need to continue to improve what we do in medicine to help people survive heart attacks,” Rosamond said. “But that’s only part of it. We also need effective, community-wide action that promotes cardiovascular health. It will be the combination of what clinicians can do for their patients and how we, as a community, manage our lives and environment that will drive further reductions in coronary heart disease death and the incidence of heart attack in the future.”
Other study authors are Lloyd E. Chambless, PhD, UNC biostatistics professor (retired); Gerardo Heiss, MD, PhD, Kenan Distinguished professor of epidemiology at UNC; Thomas H. Mosley, PhD, professor of geriatrics and gerontology at University of Mississippi-Jackson School of Medicine; Josef Coresh, MD, PhD, professor of epidemiology and biostatistics at Johns Hopkins University Bloomberg School of Public Health; Eric Whitsel, MD, MPH, research associate professor of epidemiology; Lynne Wagenknecht, DrPH, professor of public health sciences in the Wake Forest University School of Medicine; National Institutes of Health National Heart, Lung, and Blood Institute epidemiologist Hanyu Ni, PhD; and Aaron R. Folsom, MD, MPH, professor of epidemiology and community health at University of Minnesota School of Public Health.
The study, funded by the National Heart, Lung, and Blood Institute, is available online. A subscription is required.