Effects of Phase II Comprehensive Cardiac Rehabilitation on Coronary Plaque Volume After Acute Coronary Syndrome

The present study aimed to determine the effects of phase II (PII) comprehensive cardiac rehabilitation (CR) on coronary plaque volume in patients after acute coronary syndrome (ACS).We assigned 46 patients with ACS who had undergone standard phase I CR into groups who proceeded with PII-CR (PII-CR; n = 21) and those who did not (non-PII-CR; n = 25). We then measured anthropometric parameters and daily physical activity using a pedometer for up to 60 days. The isokinetic strength of the knee extensor and flexor muscles and exercise tolerance were tested and non-culprit lesions were analyzed using volumetric intravascular ultrasound at baseline and 6 months later.Baseline characteristics did not significantly differ between the two groups and exercise tolerance was significantly improved in both. Waist size and fat weight were significantly decreased, and muscle strength was significantly increased in the PII-CR group but not in the non-PII-CR group. The percent change in plaque volume (primary endpoint) did not differ significantly between the two groups. The percent change in plaque volume was significantly and negatively correlated with daily physical activity.Although risk factors, muscle strength, and exercise tolerance were improved by PII-CR, plaque regression did not differ significantly between the two study groups. A significant correlation between percent change in coronary plaque volume and physical activity was observed. A comprehensive phase II-CR, including frequent supervised exercise sessions and a program encouraging an increase in daily physical activity, may reduce plaque volume in patients after ACS (UMIN000006038).