Systematic Review of the Use of the 6-Minute Walk Test in Measuring and Improving Prognosis in Patients With Ischemic Heart Disease

Introduction: The 6-minute walk test (6MWT) has been used for over 30 years to assess exercise capacity in patients with respiratory dis-ease, and more recently, in those with heart failure. However, despite being a simple and reproducible test of real-world exercise capacity, its use in patients with ischemic heart disease (IHD) is less well accepted. We sought to review systematically the evidence surrounding the 6MWT in IHD.Methods: We searched the Medline, PubMed, Embase, and Scopus databases for the following key terms: "six minute walk test/6 minute walk test/6MWT" and "angina/coronary artery disease/coronary dis-ease/IHD/ischemic heart disease." We followed Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines to select publications for full-text review and analyzed the collated data.Results: A total of 1228 unique papers were found, of which 71 were chosen for full-text review and 37 for detailed analysis. Most (23) concerned the effect on 6MWT distance (6MWTd) of cardiac rehabilitation, with measurements commenced after an intervention (acute myocardial infarction, n = 4; open heart surgery (OHS), n = 5; percutaneous coronary intervention (PCI), n = 3; or other, n = 11). The effect on 6MWTd of OHS was investigated in 6 studies and of PCI in one study. The 6MWT is a useful measurement of physical capacity; data are limited on its ability to assess benefit following PCI. Conclusions: The 6MWT has been studied inconsistently in IHD. The majority of data are on patients before and after CR. Data are limited concerning the effect on 6MWTd of OHS or PCI. The available data support the 6MWT as a measure of change in performance status following coronary intervention. More work is required to confirm this hypothesis.