Abstract
Background Aerobic exercise capacity is inversely associated with cardiovascular and all-cause mortality in men and women without coronary artery disease (CAD); however, a higher amount of vigorous exercise is associated with a J-shaped relationship in CAD patients. Therefore, the optimal type and amount of exercise for CAD patients is unclear. Coronary artery calcification (CAC) is associated with increased cardiovascular disease (CVD) events and mortality. Fatty plaque is more likely to rupture and cause coronary events than other types. We examined the association between exercise capacity, fatty plaque, CAC score and CVD events in CAD patients. Methods and Results A total of 270 subjects with stable CAD were divided into tertiles based on metabolic equivalents of task (METs) calculated from exercise treadmill testing. Self-reported exercise was obtained. Coronary computed tomographic angiography measured coronary plaque volume and CAC score. After adjustment, fatty plaque volume was not different among the 3 MET groups. For each 1 MET increase, CAC was 66.2 units lower (P=0.017). Those with CAC >400 and ≥8.2 METs had fewer CVD events over 30 months compared to <8.2 METs (P=0.037). Of moderate intensity exercisers (median, 240 min/wk; 78% walking only), 62.4% achieved ≥8.2 METs and lower CAC scores (P=0.07). Intensity and duration of exercise had no adverse impact on coronary plaque or CVD events. Conclusions Achieving ≥8.2 METs with moderate exercise intensity and volume as walking resulted in lower CAC scores and fewer CVD events. Therefore, vigorous exercise intensity and volume may not be needed for CAD patients to derive benefit. Registration URL: https://www.clinicaltrials.gov; Unique Identifier: NCT01624727.