Impact of exercise testing mode on exercise parameters in patients with chronic heart failure

Aim: To verify the impact of testing mode on maximal, sub-maximal parameters and on cardiopulmonary exercise test (CPET) derived prognostic markers in patients with chronic heart failure (CHF). Method: 55 patients (age 60.3 years +/- 11.1) with CHF (ejection fraction 26 %+/- 8) underwent a maximal CPET on a bicycle and on a treadmill, in a random order, within one week. Maximal, sub-maximal parameters and CPET derived prognostic markers were compared. Results: VO(2)peak and VO(2)peak corrected for lean body mass were significantly higher on treadmill compared to bicycle (+/- 11%, p < 0.0001). This was also the case for the following sub-maximal parameters; heart rate, workload and VO2 at ventilatory anaerobic threshold and VO2 at the respiratory compensation point (RCP). In contrast, both VE/VCO2 slopes (start to RCP and start to end test) were similar. Time to 1/2 VO(2)peak was longer and circulatory power was higher on the treadmill compared to exercise testing on the bicycle. Conclusion: The results of the present study suggest that the mode of exercise testing significantly affects absolute values for VO(2)peak but does not greatly impact the prognostic utility of the VE/VCO2 slope in patients with moderate to severe CHF. Besides the consequences of these findings in terms of prognostication, testing mode should be taken into consideration when exercise prescription is based on VO(2)peak.