Independent predictors and equation of six-minute walk test in post-cardiac surgery

Abstract

Background: The six-minute walk test (6MWT) has been used to evaluate postsurgical recovery in cardiac patients. No previous study has compared the 6MWT at follow-up with a baseline, or evaluated the long-term effects of cardiac surgery on post-discharge 6MWT Objectives: To identify the factors independently associated with 6MWD, and to develop an equation to predict 6MWT at the 4–6-week follow-up after post-cardiac surgery hospital discharge. Methods: Patient data of elective coronary artery bypass graft (CABG) or non-CABG surgery patients were retrospectively collected. The 6MWT was performed at hospital discharge and at the 4–6-week follow-up. Available demographic and clinical data of patients were analyzed to determine the independent factors of 6MWT. An equation to predict 6MWT were generated by forward stepwise multiple linear regression analysis. Results: The data of 275 patients (mean age: 62.20±14.57 years, 64.7% male) were analyzed. The mean 6MWT was 179.14±92.18 m at discharge, and increased to 335.20±115.51 m at the 4–6-week follow-up. The 6MWT at the 4–6-week follow-up was independently correlated with 6MWT at discharge, regular exercise, age, gender, and preoperative New York Heart Association (NYHA) classification. Conclusion: The independent predictors: 6MWT at discharge, regular exercise, age, gender, and NYHA classification were used to generate an equation to predict 6MWT at 4–6 weeks after hospital discharge.