The intervention group underwent the cardiac rehabilitation program from the first day following surgery regarding the clinical guideline for rehabilitation in patients with cardiovascular disease.17 This rehabilitation exercise program formed of breathing exercises, lower and upper extremity exercises in bed, sitting on the edge of the bed, standing at the bedside, and walking around the bed and for 100 m in the ward. The patient performed three sessions per day, with approximately 20 minutes each time. After the rehabilitation exercise, patients continued with gait practice for up to 500 m and carried out endurance training by using a stationary bike in the rehabilitation center of the hospital.

The sessions continued until they were discharged from the hospital (approximately 5 to 6 days post operative). The intensity of physical activity was limited by clinical conditions and activity tolerance, and monitored and assessed by physical therapists, plus routine clinical care.

The control group did not joined any rehabilitation program and only received routine clinical care during the duration of the hospital stay (approximately 5 to 6 days post operative).

Data collection The investigators assessed all patients on the day before surgery (baseline assessment) and the day of hospital discharge.

The intervention group underwent the cardiac rehabilitation program from the first day following surgery regarding the clinical guideline for rehabilitation in patients with cardiovascular disease.17 This rehabilitation exercise program formed of breathing exercises, lower and upper extremity exercises in bed, sitting on the edge of the bed, standing at the bedside, and walking around the bed and for 100 m in the ward. The patient performed three sessions per day, with approximately 20 minutes each time. After the rehabilitation exercise, patients continued with gait practice for up to 500 m and carried out endurance training by using a stationary bike in the rehabilitation center of the hospital.

The essions continued until they were discharged from the hospital (approximately 5 to 6 days post operative). The intensity of physical activity was limited by clinical conditions and activity tolerance, and monitored and assessed by physical therapists. Plus routine clinical care

Oxygen saturation: (2700 Branshaj, Denemark).

Forced vital capacity (FVC)

forced expiratory volume in the first second (FEV1)

The ratio of FEV1 on FVC.

The 6-Minute Walk Test (6MWT): We performed the 6-minute walking test (6MWT), which involved measurement of the 6-minute walking distance and is a submaximal functional test indicative of performing daily activities.18 The safety and feasibility of this test have led to its use in cardiovascular rehabilitation.