Metabolic Equivalent of Exercise Stress Test Explained by Six-Minute Walk Test in Post Coronary Artery Bypass Graft and Post Percutaneous Coronary Intervention Patients
Watesinee Khuangsirikul MSc*, Wattana Jalayondeja PhD*, Rungchai Chuanchaiyakul PhD**, Rungroj Krittayaphong MD***, Chunhakasem Chotinaiwattarakul MD***, Pansak Laksanabunsong MD***
Affiliation : * Faculty of Physical Therapy, Mahidol University, Nakhon Pathom, Thailand ** College of Sports Science and Technology (CSST), Mahidol University, Nakhon Pathom, Thailand *** Division of Cardiology, Department of Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand **** Her Majesty Cardiac Center, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand ***** Division of Cardio Thoracic Surgery, Department of Surgery, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
Objective : To investigate the relationship among metabolic equivalents of an exercise stress test (METs of EST), demographic
parameters (age, body weight, height, BMI), peak oxygen consumption (VO2 peak), and six-minute walk distances (6MWD)
determined from a six-minute walk test (6MWT).
Material and Method: Exercise capacity was estimated by a 6MWT and EST at the sixth week post operation in post coronary
artery bypass graft (post CABG, n = 17) and post percutaneous coronary intervention (post PCI, n = 13) patients.
Results : METs of EST showed: high correlation (p<0.01) with VO2 peak of 6MWT (r = 0.94), 6MWD (r = 0.92); muscle
strength (r = 0.78), moderate correlation (p<0.01) with height (r = 0.53); negative correlation with age (r = -0.50). Low
correlation was found (p<0.05) with step length (r = 0.43), and weight (r = 0.38). No correlation was found among METs of
EST and rating perceived exertion (RPE) of EST and 6MWT. The multiple linear regression equation for explaining METs of
EST is as follows: METs of EST = -2.94+0.02 (6MWD), (r = 0.923, R2 = 0.85, p<0.001).
Conclusion : The 6MWT may possibly be used as an alternative choice for estimating energy expenditure to design exercise
programs for these post operation groups.
Keywords : Metabolic equivalents, Peak oxygen consumption, Post coronary artery bypass graft, Post percutaneous coronary intervention, Six-minute walk test
