Correlation of the sit-to-stand test, the walk test and waist circumference before cardiac surgery

Abstract

The postoperative period of cardiac surgery interferes with peripheral muscle strength, which can be assessed by a 1-minute sit-to-stand test (STST). Our objective was to correlate STST and preoperative physical-functional variables and secondarily to correlate with gender, clinical and surgical variables, comorbidities, risk factors and postoperative complications. Cross-sectional and analytical study of patients undergoing elective cardiac surgery between 2010 and 2017. On the day before surgery, an evaluation was performed to quantify performance of the STST and the functional physical variables (six-minute walk test - 6MWT, respiratory muscle strength assessed by maximal inspiratory (MIP) and expiratory (MEP) pressure and waist circumference). Clinical and surgical variables (ejection fraction, time on mechanical ventilation, length of stay in the intensive care unit and total length of stay), comorbidities and risk factors (hypertension, diabetes mellitus, chronic obstructive pulmonary disease, acute myocardial infarction, smoking, alcoholism, physical inactivity and stress) and postoperative complications were collected from patient’s medical records. A population of 154 individuals obtained a mean of 17.32±5.02 repetitions in STST. There was a direct correlation with the 6MWT (r= 0.330; p= 0.004), the percentage of MIP (r= 0.115; p= 0.001) and MEP (r= 0.212; p= 0.004) and an inverse correlation with waist circumference (r= -0.238; p= 0.003) and age (r= -0.294; p= 0.001). There was a better performance of STST correlated with males (p= 0.032) and those with lower stress levels (p= 0.012). It is concluded that there is a correlation between the STST and the 6MWT, respiratory muscle strength and waist circumference, as well as male gender and stress.