Y Effects Of Low Intensity Resistance Exercise Under Kaatsu Condition On Skeletal Muscle Size And Its Safety Incardiovascular Surgery Patients

Introduction: Surgery for cardiovascular disease is often accompanied by sarcopenia and physical frailty, and improvement of muscle mass, muscle strength, and ADL, is often difficult only with cardiac rehabilitation using aerobic exercise. The resistance training under moderately restricted muscle blood flow, named as KAATSU, induces muscle hypertrophy and strengthens muscle through low intensity exercise. However, it remains uninvestigated whether KAATSU resistance training using low intensity load (KAATSU-RE) increases muscle strength, and induces hypertrophy in patients early after cardiovascular surgery. Hypothesis: To investigate the effects of KAATSU-RE on skeletal muscle strength, hypertrophy and its safety in patients early after cardiovascular surgery. Methods: Nine patients early after cardiac surgery were included in this study (seven males, age 54 ± 18 years, BMI 23.0 ± 3.7 kg/m 2 , AVR 5 cases, MVP 3, Bentall operation 1). The patients performed leg extension exercise (20~30% 1RM) under KAATSU condition two times/week for three months. Training started after 200 m walking early after the operation. Skeletal muscle mass index (SMI) was evaluated using bioelectrical impedance analysis (BIA). The anterior mid-thigh thickness (MTH) was measured using B mode transverse ultrasound images. Physical functions (isometric knee extension peak torque, handgrip strength, and walking speed) were also measured at three points, i.e. baseline (before operation), ~7 days early after operation, and ~3 months after the training. Results: SMI and MTH decreased significantly from 7 ± 1.1, and 2.5 ± 0.4 cm preoperatively to 6.7 ± 1.0, and 2.2 ± 0.3 cm approximately 1 week after surgery. Approximately 3 months after the training, they increased significantly to 7.6 ± 0.8 and 3 ± 0.4 cm. During the rehabilitation period, hemodynamic deterioration and side effects including subcutaneous hemorrhage were not observed, and all the patients completely finished the study. Conclusions: These results suggest that KAATSU training safely increased muscle mass in patients in the early perioperative period of cardiovascular surgery. KAATSU training appears to be a promising and effective method for cardiac rehabilitation in patients with cardiovascular surgery.