About the Study

Despite experiencing a recent life-threatening cardiac event, only 15-40% of persons having cardiac events are exercising 6 months later. This downward trajectory of exercise during the year following a cardiac event has resulted in a large number of cardiac patients who are not exercising at levels needed to achieve and/or retain the health benefits of exercise. In this randomized trial of 250 participants, we evaluated the effectiveness of CHANGE, a lifestyle modification program designed to increase exercise maintenance following a cardiac event (myocardial infarction, coronary artery bypass surgery and/or angioplasty).

The CHANGE intervention consists of five small-group counseling sessions in which participants are taught self-efficacy enhancement, problem-solving skills, and relapse prevention strategies to address their identified exercise maintenance barriers. Participants (155 men, 95 women) had a mean age of 62 y (range 38-86 y) and were Caucasian (81%) or African American (17%). Exercise was measured using portable wristwatch heart rate monitors worn during exercise for one year following completion of a cardiac rehabilitation program.

Cox proportional hazards regression was used to determine differences in exercise maintenance over the study year between the CHANGE group and a comparison group receiving usual care. Results indicated that participants in the usual care group were 76% more likely than those in the CHANGE group to stop exercising during the year following a cardiac rehabilitation program (HR=1.76, 95% CI = [1.08-2.86], p = .02) when adjusting for significant covariates race, gender, co-morbidity, muscle and joint pain, and baseline motivation. It was also found that men were less likely to discontinue exercising than women (HR=0.59, 95% CI º [0.36, 0.95]) and non-Hispanic Caucasians were less likely to discontinue exercising than minorities (HR=0.56, 95% CI º [0.33, 0.95]). Further, those with higher co-morbidity scores (HR=01.18, 95% CI º [1.01-1.38]) and more muscle and joint pain were more likely to discontinue exercising (HR=1.46, 95% CI º [1.14, 1.87]) and those with higher motivation were less likely to discontinue exercise (HR= 0.95, 95% CI º [0.92, 0.99]). No significant differences were found in exercise frequency, amount, and intensity compliance (amount of time subjects exercise in target heart rate zone) over the study year between the CHANGE and Usual Care groups. Additionally, no group-by-race or -gender interactions were found. Measures of self-efficacy, benefits/barriers for exercise, social support, problem solving, and motivation, that were hypothesized as the mechanisms through which the CHANGE intervention would increase exercise, showed little change over the study period and did not differ by study group. We conclude that counseling interventions of sufficient dose that utilize contemporary behavior change strategies can reduce the number of individuals who do not exercise following cardiac events; however, the general trend reveals less than recommended levels of physical activity participation.