From Our 2010 Archives

Heart Attacks Down Sharply, Study Finds

24% Decline in Heart Attack Hospitalizations in California Population Since 2000

By Salynn Boyles
WebMD Health News

Reviewed by Laura J. Martin, MD

June 9, 2010 -- Fewer Americans are having heart attacks, and more people who do have them are surviving, new research confirms.

Between 2000 and 2008, heart attack hospitalizations declined by 24% among enrollees of the health care provider Kaiser Permanente living in northern California.

Heart attack deaths also dropped, in large part because of an even steeper decline in a particularly deadly type of heart attack known as ST-elevation myocardial infarction, Kaiser researchers reported in the June 10 issue of the New England Journal of Medicine.

A study of Medicare recipients reported in early April showed a similar reduction in heart attack- related hospital admissions among elderly Americans between 2002 and 2007.

Experts say the precipitous decline confirms that better management of heart disease risk factors such as high blood pressure and high cholesterol is having an impact, as are efforts to reduce smoking, ban smoking in public places, and get people to eat healthier and exercise.

"This is really very good news, and it is a pretty strong indication that aggressive treatment of heart disease risk factors is making a difference," American Heart Association spokesperson and Northwestern University assistant professor of preventive medicine Mercedes Carnethon, PhD, tells WebMD.

Heart Attacks, Deaths Declining

Between 1999 and 2008, just over 46,000 heart attack hospitalizations occurred among about 3 million enrollees of the Kaiser Permanente Northern California health system.

The analysis of hospital data revealed that heart attacks declined steadily from 2000 to 2008 -- the last year for which data were available.

During the same period, the percentage of patients whose blood pressure was controlled to target levels doubled, from 40% to 80%.

Target low-density lipoprotein (LDL) levels were lowered in patients with coronary disease during the period, from less than 130 milligrams per deciliter to less than 100 milligrams per deciliter. Even so, more people reached the target LDL level in 2008 than in 1999 (73% vs. 67%).

Of the 4,068 Kaiser enrollees hospitalized for heart attacks in 2008, 76% had poorly controlled high blood pressure, 80% had high LDL cholesterol, and 32% had diabetes.

"In heart disease, as with other medical conditions, we are always looking for new and better treatments," lead researcher Alan S. Go, MD, of Kaiser's research division, tells WebMD. "But these findings make it clear that we can have a profound impact by using the treatments we already have."

The study was among the first to separate ST-elevation heart attacks, which cause major injury to the heart muscle, from heart attacks that tend to be less severe.

During the study period, ST-elevation heart attacks declined by 62%, but the death rate among people who had these severe heart attacks did not drop.

The death rate did significantly decrease in patients with less severe non-ST elevation heart attacks from 10% to 7.6%.

Trend Among Uninsured Unknown

Harlan Krumholz, MD, of Yale University Medical Center, calls the large decline in heart attack hospitalizations over the past decade "nothing short of amazing," but he adds that the growing number of new cases of obesity and diabetes in the U.S. are ominous signs for the future.

Krumholz was principal investigator of the Medicare study reported earlier this spring, which showed a 23% decline in heart attack hospitalizations among elderly Medicare beneficiaries between 2002 and 2007.

"If obesity and diabetes continue to rise, I fear these declines won't be sustained for very long," he says. "For now, though, it is clear that something important is going on in cardiovascular medicine."

Carnethon adds that heart attack incidence has probably not declined as much among uninsured people with little access to preventive care.

"The people in these studies were all insured," she says. "I would guess that we would not see the same pattern of decline in people without health insurance."

SOURCES:
Yeh, R.W. New England Journal of Medicine, June 10, 2010; vol 362: pp 2155-2165.
Alan S. Go, MD, Division of Research, Kaiser Permanente Northern California, Oakland, Calif.
Harlan M. Krumholz, MD, professor of medicine, division of cardiovascular medicine, Yale University School of Medicine, New Haven, Conn.
Mercedes Carnethon, PhD, assistant professor of preventive medicine, Northwestern University Feinberg School of Medicine, Chicago; spokesperson, American Heart Association.
News release, Kaiser Permanente. Chen, J. Circulation, 2010; vol 121.
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