Optimized Peak VO2 in Predicting Advanced HF

CPET was performed in this HF cohort within one month after being discharged and interpreted as previously described. Patients underwent an upright graded cycle ergometer exercise using a personalized ramp protocol or a motorized treadmill using a modified Bruce or Cornell protocol. Peak VO2 data measured by cycle ergometer were increased by 10% to allow a comparison between the two different procedures. Peak VO2 was defined as the highest 30-second average value obtained during exercise. Submaximal CPET variables such as ventilatory efficiency were calculated by the slope of VE versus VCO2 below the ventilatory compensatory point (VCP). If the slope of VE/VCO2 can't be calculated, we used the nadir of VE/VCO2, or the ratio of VE/VCO2 at the anaerobic threshold (AT) as the variable of ventilatory efficiency. The AT was determined by the V-slope method.