Thompson PD, Franklin BA, Balady GJ, Blair SN, Corrado D, Estes NAM III, Fulton JE, Gordon NF, Haskell WL, Link MS, Maron BJ, Mittleman MA, Pelliccia A, Wenger NK, Willich SN, Costa F, In collaboration with the American College of Sports Medicine

Circulation. 2007;115:2358-2368 (AHA Scientific Statement).

Habitual physical activity reduces coronary heart disease events, but vigorous activity can also acutely and transiently increase the risk of sudden cardiac death and acute myocardial infarction in susceptible persons. This scientific statement discusses the potential cardiovascular complications of exercise, their pathological substrate, and their incidence and suggests strategies to reduce these complications. Exercise-associated acute cardiac events generally occur in individuals with structural cardiac disease. Hereditary or congenital cardiovascular abnormalities are predominantly responsible for cardiac events among young individuals, whereas atherosclerotic disease is primarily responsible for these events in adults. The absolute rate of exercise-related sudden cardiac death varies with the prevalence of disease in the study population. The incidence of both acute myocardial infarction and sudden death is greatest in the habitually least physically active individuals. No strategies have been adequately studied to evaluate their ability to reduce exercise-related acute cardiovascular events. Maintaining physical fitness through regular physical activity may help to reduce events because a disproportionate number of events occur in least physically active subjects performing unaccustomed physical activity. Other strategies, such as screening patients before participation in exercise, excluding high-risk patients from certain activities, promptly evaluating possible prodromal symptoms, training fitness personnel for emergencies, and encouraging patients to avoid high-risk activities, appear prudent but have not been systematically evaluated.

Editor's Comment.

This statement published in Circulation is the most recent AHA Scientific Statement addressing exercise. The authors go to great lengths to evaluate the risks versus the benefits of exercise for various populations, including the youth, athletes, and both apparently healthy adults and adults with coronary heart disease. The statement also discusses various strategies to moderate risk. Although there is little doubt that the time period during activity and certainly during vigorous activity increases risk of coronary event and sudden cardiac death, the reasons for this are less well defined. Adults who are less physically active and less fit are at greater risk of event during sudden, vigorous exercise. The authors also accurately state that events and complications during supervised exercise (ie, formal cardiac rehabilitation programs) are rare, probably for several reasons, including appropriate medical screening of patients before entry and staff preparedness for emergency situations, both of which "support the use of supervised exercise-based cardiac rehabilitation programs" after cardiovascular disease and cardiac events. There is much important information to be gleaned from this statement, and it is readily accessible for clinical professionals.

JR