For cardiopulmonary exercise testing (CPET), patients exercise on either a stationary bike or a treadmill. Cardiac, respiratory, and metabolic function are measured during warm-up and then during progressively more intensive exercise culminating with exhaustion. As I tell my patients, "if you want to pinpoint and quantify the reasons for your exercise symptoms, this is the best test that medicine has to offer." Several major organizations concur.
CPET is not without its detractors, however, and the test is far from perfect. Interpretation remains challenging for many reasons, one of which is the absence of a good reference set to establish normative values. The 2003 CHEST/ATS guidelines on CPET discuss reference equations and recommend using sets published by Jones or Hansen and colleagues. These are the reference sets programmed into the software that we use at our lab. But both were published in the 1980s and sampled small, rather homogeneous populations. In short, they're helpful but limited.
In a recent CHEST journal issue, investigators from the CanCOLD Collaborative Research Group and the Canadian Respiratory Research Network published new CPET reference equationsThere's a lot to like about their data. Screening for baseline disease and abnormalities was rigorous, data collection was comprehensive, their sample size was relatively large for a CPET study (N = 173), they documented baseline activity levels, and they included a validation cohort to test their derived equations. They also compared their findings with those predicted by Jones and Hansen.
