Background. The prognostic value of cardiopulmonary exercise testing (CPET) is known, but the predictive value of 6MWT in patients with heart failure (HF) and patients undergoing coronary artery bypass grafting (CABG) is not established yet. Objective. We conducted a systematic review exploring the prognostic value of 6MWT in HF patients undergoing cardiac surgery. The aim was to find out whether the change in the distance walked during follow-up visits was associated with prognosis. Data Source. We searched “PubMed” from January 1990 to December 2012 for any review articles or experimental studies investigating the prognostic value of 6MWT in HF patients and patients undergoing cardiac surgery. Results. 53 studies were included in the review, and they explored the role of 6MWT in cardiology, cardiac surgery, and rehabilitation. The results did not show the relation between the six-minute walk distance and adverse events after CABG. The predictive power of the distance walked for death in HF patients undergoing cardiac surgery was not found. It is not yet proved if the change in the six-minute walk distance is associated with prognosis. The predictive power of the six-minute walk distance for death in HF patients undergoing cardiac surgery remains unclear. 1. Background 1.1. Definition and History of Implementation of the Six-Minute Walk Test The six-minute walk test is a simple, inexpensive, and reproducible method for the assessment of exercise capacity. Implementation of the test does not require any advanced equipment or training for technicians. During the test, the patient walks the longest possible distance within the time of 6 minutes on the flat surface and can stop or slow down at any time and then resume walking during the test. The main result of the six-minute walk test (6MWT) is the distance covered by the patient in 6 minutes. The 6MWT shows good correlation with the peak VO2 from cardiopulmonary exercise test and is much easier to perform, and it reflects well the daily activities of the patients. However, many variables may influence this test, and, therefore, it should always be performed according to the strict given protocol. The 6MWT was proposed for the first time by Balke in 1963, and since the mid-1980s, it has been used more and more widely in different clinical conditions. This test is most commonly used in pulmonary diseases, but it has been successfully implemented also in patients with cardiovascular diseases, pre- and postsurgical treatment, different neurological disorders, and fibromyalgia or spinal muscular atrophy.
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