Website: American Heart Association

DALLAS, Oct. 31 – Being physically active after a first heart attack appears to significantly lower the risk of death or a second heart attack, researchers report in this week’s Circulation: Journal of the American Heart Association.

"Patients who kept physically active after a first heart attack had a 60 percent lower risk of fatal heart attack or a second nonfatal heart attack than those who did not," says author Lyn Steffen-Batey, Ph.D., who was an assistant professor of epidemiology at the University of Texas School of Public Health at the time of the study.

The results held true regardless of the severity of heart attack and also when gender, ethnicity, high cholesterol, smoking and other risk factors were considered. Steffen-Batey and colleagues investigated the risk of death or occurrence of a second heart attack, and related it to a change in level of physical activity in 406 Mexican-American and non-Hispanic white survivors of a first heart attack admitted to hospitals in the Corpus Christi, Texas, area.

People who had been active and maintained their activity level after a heart attack or who increased their activity had a 79 percent and 89 percent lower risk of death than did patients who remained sedentary, the researchers report. Those who increased their activity had a 78 percent lower risk of repeat heart attack.

In 1992, the American Heart Association classified physical inactivity as a major risk factor for heart disease, and studies have shown that physical activity can help lower blood cholesterol and blood pressure, also risk factors for heart disease. Previous studies showed that cardiac rehabilitation exercise programs helped survival, but these were smaller studies that were designed differently, explains Steffen-Batey.

This is the first such study with significant numbers of Mexican-American participants. The study is also unique because it analyzed leisure time physical activity, measured increases and decreases in activity and was specific about the type of activity performed.

Participants were interviewed about exercise habits before the heart attack and annually for two to seven years after. Activity levels were divided into two categories: sedentary and active. The patients classified as sedentary were further divided into those with no physical activity above the minimum demands of daily living, such as watching TV, desk work and taking elevators; and those who were slightly more active due to activities such as light gardening and light housework.

The active group had three levels: Mildly active (15-30 minutes of calisthenics, lifting weights, heavy gardening and heavy housework daily); moderately active (running, jogging, swimming or bicycling one to three times a week); and vigorously active, (hard or "somewhat hard" exertion at aerobics, roller skating or playing soccer at least three times a week). She notes that those who decreased their activity after heart attack retained some benefit from prior exercise. Those who had been active, but decreased their exercise level still had a 51 percent lower risk of death than did those who were always sedentary, the researchers report. Risk of second heart attack remained approximately the same.

With better medical care, the number of individuals surviving heart attacks is increasing – and thus it’s good to get the word out that exercise can help them. But Steffen-Batey warns: "I would hope that after a heart attack people are not going to go out and try to run a marathon."

Instead, she suggests heart attack patients ask their doctors about what level of exercise they should pursue immediately following a heart attack.

"We encourage people to enroll in cardiac rehabilitation following a heart attack, which is covered by insurance. Afterward, they can continue with their home exercise program under the direction of their physician," she says.

###

Steffen-Batey is now an assistant professor of epidemiology at the University of Minnesota School of Public Health. Co-authors of the study are Milton Z. Nichaman, M.D., Sc.D.; David C. Goff, Jr., M.D., Ph.D.; Ralph F. Frankowski, Ph.D.; Craig L. Hanis, Ph.D.; David J. Ramsey, Ph.D.; and Darwin R. Labarthe, M.D., Ph.D.