Six-minute walk test
The method of choice for the measurement of the exercise capacity is the six-minute walk test (6-MWT). The 6-MWT is technically simple, inexpensive, reproducible and well standardised . It correlates well with maximal cardiopulmonary exercise testing and the severity of NYHA functional class. In addition to distance walked, dyspnea on exertion (Borg scale) and finger O₂ saturation are recorded.
Walking distances, 332 m  or 250 m  and O₂ desaturation >10%  indicate impaired prognosis in PAH. With respect to treatment effects, absolute values > 380 m following 3 months of i.v. epoprostenol correlated with improved survival in IPAH patients while the increase from baseline did not .
The increase in 6-MWT distance has remained the primary end-point in most pivotal PAH RCTs. The test is not sufficiently validated in PAH subgroups and is influenced by (but not corrected for) body weight, sex, height, age and patient motivation .
Video on 6-min walk test
Physicians in Switzerland may order a video (on CD/DVD) with detailed information on the 6-min walk test free of charge at: Actelion Switzerland, firstname.lastname@example.org
The video is based on the American Thoracic Society (ATS) guidelines for the 6-min walk test. It has been reviewed by Professor L. Rubin (UCSD) and Professor R. Speich (University Hospital Zürich). We express our thanks and gratitude to the Department of Internal Medicine (University Hospital Zürich) for allowing to film in their facilities. Special thanks to Ursula Treder for her active cooperation.
Original music composed by Carine Perret.