The importance of an exercise testing protocol for detecting changes of peak oxygen uptake in cardiac rehabilitation

Objective: To assess which exercise testing protocol is most sensitive for assessing peak oxygen uptake (Vo(2)peak) changes as a result of cardiac rehabilitation. Design: Prospective randomized clinical trial. Setting: Outpatient cardiac rehabilitation center. Participants: Forty-two cardiac patients (33 men; mean age, 65.4+/-8.4y). Intervention: All patients were included into a 7-week cardiac rehabilitation program and randomized in 2 subgroups. One group of patients was evaluated by a 1-minute stage (n=21) and another group by a 3-minute stage (n=21) exercise testing protocol. Main Outcome Measures: In both groups, maximal cardiopulmonary exercise tests on a bicycle with analysis of Vo(2)peak, expiratory volume ((V) over dot(E)), respiratory exchange ratio, heart rate, cycling resistance (W), and test duration were performed at the start and end of the program. Results: Subgroups were closely matched, and no changes in beta-blocker treatment occurred during this study. As result of the rehabilitation program, total test duration and Wpeak improved significantly in both groups (P<.05). Nonetheless, Vo(2)peak and VEpeak increased significantly in the 1-minute stage duration group (P<.05) but not in the 3-minute stage duration group (P>.05). In addition, the change of Vo(2)peak, VEpeak, and total test duration was significantly greater in the 1-minute stage duration group compared with the 3-minute stage duration group (P<.05). Conclusions: For detecting changes Of Vo(2)peak as result of cardiac rehabilitation, a 1-minute stage exercise testing protocol is more sensitive when compared with a 3-minute stage exercise testing protocol.