Study highlights:
• Blood vessel function improves after just four weeks of exercise in heart attack survivors.
• Aerobics and resistance training programs, or a combination, are safe for people who have had a heart attack.
• The positive effect on blood vessels does not last unless patients continue to exercise regularly. People in this study lost the benefit four weeks after stopping exercise.

DALLAS, March 16, 2009 — Aerobic exercise, resistance training and both together safely improved blood vessel (or endothelial) function after heart attack, but quitting training quickly caused the improvements to lapse, according to a study reported in Circulation: Journal of the American Heart Association.

“While it is generally accepted that exercise training for people with coronary artery disease improves vascular function, controversy still exists regarding the right level and right format of exercise,” said Margherita Vona, M.D., lead author of the study and a cardiologist and director of the Cardiac Rehabilitation Center, Clinique Valmont-Genolier in Glion sur Montreux, Switzerland.

Researchers assessed the effect of different types of exercise, as well as the effect of stopping exercise in 209 people who’d had heart attacks. They measured participants’ endothelial function at the start of the study and after four weeks of training. Participants then quit their training for one month and researchers measured blood vessel function again.

The researchers randomly assigned the patients to receive aerobic training, resistance training, aerobic and resistance training combined, or no training:
• The aerobics participants underwent moderate training four times a week for a month. Each session included a 10-minute warm-up, 40 minutes of cycling at an intensity of 75 percent of maximum heart rate and a 10-minute cool-down.
• The resistance training group did four sets of 10 resistance exercises repeated 10–12 times, for a total of 40 exercises four times a week for four weeks — a controlled, moderate-intensity training as recommended by the American Heart Association’s guidelines for resistance training.
• The combined group alternated controlled resistance and controlled aerobic training sessions.

The endothelial function of those in the three exercise groups improved after four weeks of exercise, regardless of the type of exercise, researchers said. The endothelial function on the non-exercising group, however, did not improve significantly.

Researchers used flow-mediated dilation (FMD) to measure blood vessel function.

After one month of training, FMD increased from about 4 percent before the exercise programs, to about 10 percent (which is normal function) in trained patients. Researchers found no significant change in the non-training group (FMD increased from 4.3 percent to 5.1 percent).

However, after one month of detraining, or stopping regular exercise, all the positive effects on endothelial function were lost. Thus, long-term adherence to training programs is necessary to maintain vascular benefits on endothelial function, Vona said.

“This aspect is particularly important in patients with coronary artery disease, in whom the correction of endothelial dysfunction could help to slow the progression of atherosclerosis and probably avoid subsequent heart attacks,” she said. “All the types of exercise were well tolerated and did not cause any complications in our patients.

“This should be an additional reason to encourage patients to carry out several types of physical activity to avoid exercise boredom and promote better long-term adherence to exercise programs.”

The study was funded by Clinique Valmont-Genolier.

Co-authors are: G.M. Codeluppi, M.D.; T. Iannino, M.D.; E. Ferrari M.D.; J. Bogousslavski, M.D.; and L. von Segesser, M.D. Author disclosures are on the manuscript

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Editor’s Note:
MyStart! Online is a free physical activity tracking tool from the American Heart Association. In April new walking programs will be added, so walkers of varying abilities can download a free customized plan. The plans were developed with help from the American Council on Exercise. To use the tool, visit heart.org/start.

To learn more about heart attack risks or how to recover from a heart attack, visit www.hearthub.org/heartattack.   

Statements and conclusions of study authors that are published in American Heart Association scientific journals are solely those of the study authors and do not necessarily reflect the association’s policy or position. The association makes no representation or guarantee as to their accuracy or reliability. The association receives funding primarily from individuals; foundations and corporations (including pharmaceutical, device manufacturers and other companies) also make donations and fund specific association programs and events. The association has strict policies to prevent these relationships from influencing science content. Revenues from pharmaceutical and device corporations are available at www.americanheart.org/corporatefunding.  

NR09 – 1041 (Circ/Vona)