DETROIT - People who are fit are more likely to survive their first heart attack, according to a study of nearly 70,000 patients of Henry Ford Hospital in Detroit.
The results of the study by Henry Ford and the Johns Hopkins University School of Medicine will be published online February 1 in Mayo Clinic Proceedings.
"Our data suggests that doctors working with patients with cardiovascular risk factors should be saying, 'Mr. Jones, you need to start an exercise program now to improve your fitness and chance of survival, should you experience a heart attack,'" says Clinton Brawner, PhD., Clinical Exercise Physiologist and Senior Bioscientific Clinical Staff Researcher at Henry Ford Health System. "These findings suggest that higher aerobic fitness before a heart attack is associated with better short-term survival after the first heart attack."
While several prior studies have reported a strong relationship between fitness and long-term risk of death in various patient populations, the study is the first to examine the association of early death following a first heart attack. The analysis is part of the Henry Ford Exercise Testing Project, or FIT Project, a study of nearly 70,000 adults who completed a physician referred exercise stress test at Henry Ford Health System between 1991 and 2009.
In the current analysis of the Henry Ford data, the researchers focused on 2,061 patients who suffered their first heart attack after the stress test, during follow-up. Mean time between the exercise test and the first heart attack was six years.
Patients with a high level of fitness during their initial stress test at a Henry Ford Health System facility were 40% less likely to die within a year following their first heart attack compared to patients with lower fitness, according to the study.
"We knew that fitter people generally live longer, but we now have evidence linking fitness to survival after a first heart attack," says Michael Blaha, M.D., M.P.H., director of clinical research at the Ciccarone Center for the Prevention of Heart Disease and assistant professor of medicine at the Johns Hopkins University School of Medicine. "It makes sense, but we believe this is the first time there is documentation of that association."
Those Henry Ford patients who were more active also reduced their likelihood of dying during the year following their first heart attack by 8 to 10% for each level of increased fitness they had reached during the stress test.
The results suggest that low fitness may represent a risk of death following a heart attack that is similar to traditional risk factors, such as smoking, high blood pressure, or diabetes, says Henry Ford's Dr. Brawner. The findings suggest doctors should include exercise when counseling patients about controlling their risk factors.
"While up to 50% of fitness may be based on genetics, physical activity is the only behavior we have that can improve fitness," Dr. Brawner says.
Follow-up studies are needed to formally establish whether exercise training among individuals with low fitness and increased risk for a heart attack reduces the short-term mortality risk following a first heart attack, Dr. Brawner added. Investigators also intend to look at whether patients with low fitness suffer more damage to their heart during their heart attack.
The primary investigator of the FIT project is Henry Ford cardiologist Mouaz Al-Mallah, M.D.
The lead author of the present analysis was Gabriel Shaya, M.S., of the University of Miami.
Additional investigators include Jonathan Ehrman, Ph.D., and Steven Keteyian, Ph.D., of Henry Ford Hospital; Blaha, Rupert Hung, B.A., Khurram Nasir, M.D., and Roger Blumenthal, M.D., of Johns Hopkins; and Waqas Qureshi, M.D., of Wake Forest University.
EDITORS' NOTE: To interview Dr. Brawner or to receive a video clip, please contact Tammy Battaglia at 248-881-0809 or Tammy.Battaglia@hfhs.org To receive ongoing updates on future studies and findings associated with the Henry Ford FIT Study, email HenryFordFITStudy@hfhs.org.