Maximal workload and oxygen uptake during exercise after aortic-valve replacement

Context: It is more feasible to assess functional capacity with an exercise test than to measure peak-exercise VO2. Objective: To assess whether maximal workload reliably predicts peak VO2. Patients: Thirty-six patients after aortic-valve replacement during routine follow-up. Design: Incremental symptom-limited cycle exercise test in the upright position with increments of 20 W/min. Setting: Out-clinic patients, university hospital. Main Outcome Measures: Maximal workload, ventilatory threshold, and peak VO2. Results: Maximal workload was 151 +/- 39 W, and peak VO2, 1649 +/- 486 ml/min. The correlation coefficient between maximal workload and peak VO2 was r =.92 (P <.0001). The regression equation for the estimation of peak VO2 was y = 11.7 (maximal workload in watts) - 110.7. Peak VO2 calculated with this equation was 1657 +/- 451 ml/min. Conclusions: Maximal workload during ergometry in the upright position reliably predicted peak VO2.