Determining the Preferred Percent-Predicted Equation for Peak Oxygen Consumption in Patients With Heart Failure

Abstract

Background-Peak oxygen consumption (VO 2 ) is routinely assessed in patients with heart failure undergoing cardiopulmonary exercise testing. The purpose of the present investigation was to determine the prognostic ability of several established peak VO 2 prediction equations in a large heart failure cohort. Methods and Results-One thousand one hundred sixty-five subjects (70% males; age, 57.0Ϯ13.8 years; ischemic etiology, 43%) diagnosed with heart failure underwent cardiopulmonary exercise testing. Percent-predicted peak VO 2 was calculated according to normative values proposed by Wasserman and Hansen (equation), Jones et al (equation), the Cooper Clinic (below low fitness threshold), a Veteran's Administration male referral data set (4 equations), and the St James Take Heart Project for women (equation). The prognostic significance of percent-predicted VO 2 values derived from the 2 latter, sex-specific equations were assessed collectively. There were 179 major cardiac events (117 deaths, 44 heart transplantations, and 18 left ventricular assist device implantations) during the 2-year tracking period (annual event rate, 10%). Measured peak VO 2 and all percent-predicted peak VO 2 calculations were significant univariate predictors of adverse events (

Determination of Ventilatory Threshold using Heart Rate Variability in Patients with Heart Failure

“…Then Propranolol reduced premature ventricular beats in patients with coronary artery disease and severe ventricular arrhythmias possibly through an improvement of cardiac autonomic regulation. Like V E /VCO 2 slope, drug therapies induced controversial effects on main spectral indexes of HR, but our current observation and the results of recent studies [26,48,39] were in agreement with the results in healthy subjects which concluded that heart rate variability was a none invasive method to estimate VT 1 in individuals with metabolic or cardiac disease.…”

“…b p<0.05: significant difference between values associated at the first ventilatory threshold determined by gas exchange (VT 1 ) and cardiac thresholds determined in time (HRVT-RMSSD) or time-frequency (HRVT-HFp) domains. *Maximal measured data expressed in percentage of aged-predicted peak oxygen uptake and heart rate values according to Arena et al [39] Therefore, target heart rates and workloads used to prescribe tailored exercise training in patients with chronic heart failure based on VT 1 were often open to debate with the result that VO 2 peak became the preferred criterion for aerobic capacity compared to VT 1 in HF patients [11,13,30]. Kemps et al [21] showed that Oxygen Uptake Efficiency Slope (OUES) and the time constant of VO 2 kinetics during recovery from sub maximal constant-load exercise (tau-rec) were determined successfully in all patients in contrast with VT 1 , which could not be determined in 9% of their patients.…”

Exercise Testing and Training in Children With Congenital Heart Disease

“…18 The Wasserman equation, based on ideal body weight, is also widely used 18 (albeit somewhat more cumbersome) and may have superior predictive power. 19 Whichever equations are chosen by a laboratory, the validity of the predictions for the population served by the laboratory should be established by testing a number of normal subjects and confirming that the predicted values agree well with the results of these tests. 18 Measurements of peak V O 2 have been found to possess important clinical implications for patients with CHD.…”

Clinician’s Guide to Cardiopulmonary Exercise Testing in Adults

“…97 Recent data also suggest that reporting peak V O 2 as a percentage of that predicted by the Wasserman equation may have additional prognostic importance. 98 Peak V O 2 is typically corrected for total weight and is reported in mL ⅐ kg Ϫ1 ⅐ min Ϫ1 . Body fat, however, can represent a significant portion of total body weight, but it has little perfusion and consumes minimal oxygen.…”