Effects of Preoperative Aerobic Training for Improving Postoperative Functional Mobility in Coronary Artery Bypass Graft Patients

Coronary-Artery Bypass Grafting (CABG) is a surgical operation in which atherosclerotic plaque-blocked arteries are partially or completely bypassed using grafts taken from other arteries or veins. A median sternotomy is frequently used to do surgery [1]. The larger saphenous vein and the left internal mammary artery continue to be the most often used bypass. One of the leading causes of illness and mortality in the world today is cardiovascular disease. The risk factors that can be managed (modified) include high blood pressure, high cholesterol, smoking, diabetes, being overweight or obese, not getting enough exercise, eating poorly, and stress. Some risk factors cannot be changed: Age, gender, ancestry, and race [2]. The most prevalent form of cardiovascular illness, known as Coronary Heart Disease (CHD), is the narrowing or obstruction of the cardiac arteries brought on by atherosclerosis [3]. Functional mobility is the ability of individuals to travel from one location to another in order to engage in daily activities at home, at work, and in the community [4]. Cardiac rehabilitation programs improve physical fitness. Preoperative physical therapy is useful for patients which undergo cardiac surgery. The majority of patients who are scheduled for elective CABG stay at home and get little or no physical therapy or other therapies in the weeks leading up to their procedure. Patients’ functional and psychological status deteriorates during this time before surgery, according to evidence. Aerobic exercise is a kind of endurance activity ranging from low to high intensity and largely dependent on oxygen. Running or jogging for moderate to long distances, swimming, cycling, stair climbing, and walking are some examples of aerobic exercise .The use of aerobic training may activate anti-aging genes that are critical to cardiovascular function [4]. The use of activators may accelerate and improve cardiovascular function in coronary artery bypass graft patients [5].

Aerobic exercise is an essential component of cardiac rehabilitation provided to patients who have had heart surgery. Exercise-based cardiac rehabilitation is practiced in the United States. The goal of the current era is to enhance aerobic and functional endurance, using aerobic-based exercise to increase capacity for instance walking and stationary cycling, provide benefits such as relieving symptoms and a reduction in cardiovascular vulnerability, reduced hospital admissions and illness progression as well as death [6]. The purpose of this study was to evaluate the effect of preoperative aerobic training for improving postoperative functional mobility of Coronary Artery Bypass Graft patients [7].

Patients waiting for coronary artery bypass grafting who were willing to participate in the study and were male or female and between the ages of 40 and 60 were included. Patients with neurological impairment, pulmonary problems, or pacemaker dependent were excluded. Additionally, patients with concurrent valve disease and high blood pressure were also excluded from the study. A total of 38 patients were included in the study and nonrandomly divided into two groups. Group-1 as Aerobic training group and Group-2 as Conventional group. The Modified Healthy Heart Questionnaire was used as a screening tool. The Time Up and Go test and Canadian Cardiovascular society grading tools were used for determined functional mobility and grading the angina pectoris. Group-1 received Aerobic training in the form of Walking on a flat surface, light to moderate pace for 10-15 min and Stepping 8-12 repetitions, once a day, four days in a week for 3 weeks. Warm up and Cool down activity was also included. In Warm up activity, Range of motion exercises (8-12 repetitions) of upper and lower limb included. In Cool down activity, Static stretching exercises (8-12 repetitions) of upper and lower limb included. Group-2 received the Conventional treatment which includes the early mobilization, Deep breathing exercises include Diaphragmatic and pulse lip breathing. Huff and cough technique was also included once in a day, four days in a week for 3 weeks. The outcome measures were evaluated at Baseline, Preoperatively at 3rd week and Postoperatively before discharge. Statistical analysis was performed by using SPSS version 22. The Normality of the data was checked through the Shapiro Wilk test for all dependent variables before conducting inferential statistics. Data was found not normally distributed, then non-parametric tests were applied. Friedman test and Mann-whitney test were conducted for data analysis.

The TUG and CCS readings significantly improved at 3rd week preoperative and postoperative before discharge as compared to the baseline values in both group-1 and group-2 (P=0.00) as shown in (Table 1). There was significant improvement in mean TUG readings at 3rd week preoperative and postoperative before discharge readings in Group-1 with P<0.05. Results showed there was improvement in CCS readings at 3rd week preoperative and postoperative before discharge readings in Group-1 with P<0.05. There was significant reduction in oxygen therapy duration postoperatively in Group-1(P< 0.05) as shown in (Table 2) [8].

Table 1:Comparison of mean change in outcomes measure in Group 1 and 2.

Table 2:Comparison of mean change in outcomes measure in Group 1 and 2.

Miozzo et al. [9] conducted the study to analyze the effects of aerobic exercise and high-intensity inspiratory muscle training on a patient’s physical stamina, respiratory muscle strength, and quality of life. Two groups of 24 patients were being randomly assigned. IMT combined with aerobic exercise was given to one group, while only aerobic exercise was given to the other. At the baseline, the 12^th session, the 24^th session, and the 36th session, measurements were taken. The findings demonstrated that there was no discernible difference between the two groups. In this current study 38 patients were allocated non randomly into two groups. One received aerobic exercise and the other group received conventional treatment. Readings were taken at baseline, 3rd week preoperatively and postoperatively before discharge. Above study shows similar results to the current study, they also use aerobic exercise to improve functional capacity, in current study improve functional mobility through aerobic exercise [9]. Prabhu et al. [10] conducted a systematic review to evaluate the functional capacity and level of physical activity by performing aerobic exercises. A sum of 21 studies was considered for this review. The findings indicated that both functional capacity and degree of physical activity had significantly improved. The findings of this study were consistent with current study results because there was improvement in functional capacity [10]. Borges et al. [6] conducted a study to investigate the impact of aerobic exercise following CABG on pulmonary function and functional ability. There were 34 patients total, and they were split into two groups. One group received the standard of care. The intervention group performed additional aerobic exercise with a cycle ergometer in addition to the same routine. Prior to surgery and after hospital discharge, the readings were collected. Both groups’ pulmonary function was significantly reduced.

Functional ability was maintained in the intervention group but considerably declined in the patients in the control group. In this current study functional mobility of the aerobic training group was improved as compared to the conventional group. Functional mobility was measured by time up and go test in this study. Findings of this study were consistent with above study results, that functional capacity is improved by aerobic exercise [6]. Zanini et al. [11] conducted the research. The goal of this study was to assess how different rehabilitation techniques, such as resistance training, affected the patients’ pulmonary function and functional capacity throughout inpatient cardiac rehabilitation. This was a single blinded randomized control trial. 40 patients were randomly assigned into four groups. All groups received chest physiotherapy and exercises. Patients were accessed on postoperative day 6 and post discharge day 30. Above study showed contrary results to the current study because in the above study improved functional capacity and pulmonary function through resistance training, in the current study functional mobility improves through aerobic exercise [11]. Wajeeha et al., conducted a study to compare preoperative respiratory muscle strengthening to standard care. They came to the conclusion that respiratory muscle training significantly increased the length of oxygen therapy. In contrast to the above study, the current investigation demonstrated that aerobic exercise improved the duration of oxygen therapy [12].

It is concluded that all two groups are found effective in improving the functional mobility, Canadian cardiovascular society grading and reduced the postoperative oxygen duration therapy. But the Aerobic training group was found more effective in improving functional mobility, CCS and reduced the postoperative oxygen duration therapy as compared to the conventional group.

1. Alexander JH, Smith PK (2016) Coronary-artery bypass grafting. New England Journal of Medicine 374(20): 1954-1964.
2. Hajar R (2017) Risk factors for coronary artery disease: Historical perspectives. Heart Views: The Official Journal of the Gulf Heart Association 18(3): 109-114.
3. Malakar A, Choudhury D, Halder B, Paul P, Uddin A, et al. (2019) A review on coronary artery disease, its risk factors, and therapeutics. J Cell Physiol 234(10): 16812-16823.
4. Smith J, Taylor B (2022) Inspiratory muscle weakness in cardiovascular diseases: Implications for cardiac rehabilitation. Progress in cardiovascular diseases 70: 49-57.
5. Martins IJ (2016) Anti-aging genes improve appetite regulation and reverse cell senescence and apoptosis in global populations. Advances in Aging Research 5: 9-26.
6. Borges DL, Silva MG, Silva LN, Fortes JV, Costa ET, et al. (2016) Effects of aerobic exercise applied early after coronary artery bypass grafting on pulmonary function, respiratory muscle strength, and functional capacity: A randomized controlled trial. Journal of Physical Activity and Health 13(9): 946-951.
7. Sawatzky JAV, Kehler DS, Ready AE, Lerner N, Boreskie S, et al. (2014) Prehabilitation program for elective coronary artery bypass graft surgery patients: A pilot randomized controlled study. Clinical Rehabilitation 28(7): 648-657.
8. Steinmetz C, Bjarnason-Wehrens B, Baumgarten H, Walther T, Mengden T, et al. (2020) Prehabilitation in patients awaiting elective coronary artery bypass graft surgery–effects on functional capacity and quality of life: A randomized controlled trial. Clin Rehabil 34(10): 1256-1267.
9. Miozzo AP, Stein C, Marcolino MZ, Sisto IR, Hauck M, et al. (2018) Effects of high-intensity inspiratory muscle training associated with aerobic exercise in patients undergoing CABG: Randomized clinical trial. Brazilian Journal of Cardiovascular Surgery 33(4): 376-383.
10. Prabhu N, Maiya A, Prabhu N (2020) Impact of cardiac rehabilitation on functional capacity and physical activity after coronary revascularization: A scientific review. Cardiol Res Pract.
11. Zanini M, Nery R, Lima JD, Buhler R, Silveira AD, et al. (2019) Effects of different rehabilitation protocols in inpatient cardiac rehabilitation after coronary artery bypass graft surgery: A randomized clinical trial. J Cardiopulm Rehabil Prev 39(6): E19-E25.
12. Sahar W, Ajaz N, Haider Z, Jalal A (2020) Effectiveness of pre-operative respiratory muscle training versus conventional treatment for improving post operative pulmonary health after coronary artery bypass grafting. Pak J Med Sci 36(6): 1216-1219.