6-minute walk test -independant prognostic marker?

In heart failure prognosis is related to the severity of impairment of functional capacity.1 The peak oxygen consumption (VO2) at cardiopulmonary exercise test (CPET) is considered the gold standard for the evaluation of exercise tolerance; nevertheless, its clinical application is limited. The 6-minute walk test (6MWT) has been proposed as a simple, inexpensive, reproducible alternative to the CPET. The 6MWT reproduces the activity of daily life and this is particularly relevant in elderly patients who usually develop symptoms below their theoretical maximal exercise capacity.2 The test showed a good reproducibility and is largely independent from aetiology of heart failure, NYHA class and indices of left ventricular systolic or diastolic function measured at rest.