Relationship between right ventricular ejection fraction and maximum exercise oxygen consumption:: A methodological study in chronic heart failure patients

Background. Peak oxygen consumption at maximum exercise (peak VO2) predicts survival in chronic heart failure (CHF) patients. Right ventricular ejection fraction (RVEF) at rest has been reported to correlate with peak VO2. We evaluated the strength and consistency of the association between peak VO2 and RVEF measured by different radionuclide ventriculography (RNV) techniques in a prospective cohort study. Methods and Results. In 58 consecutive CHF patients (mean age, 53 years; 39 patients with dilated cardiomyopathy; 48 men), upright symptom-limited bicycle ergometry was performed. During exercise, ventilatory and gas exchange data were recorded and peak VO2 was calculated. RVEF was calculated by use of first-pass (FP) RNV with single and dual region of interest (ROI) acquisition and planar multigated acquisition (MUGA). Irrespective of the method used, RVEF showed no relevant correlation with the corresponding peak VO2 value (r = 0.11 for FP single ROI, r = 0.06 for FP dual ROI, r = 0.16 for MUGA). Peak VO2 or changes in peak VO2 after 6 and 12 months of follow-up were not determined by RVEF measurements. Conclusion. In CHF patients no association was found between peak VO2 at maximum exercise and RVEF at rest with different RNV techniques. Changes in exercise capacity are not reliably reflected by changes in RVEF measurements at rest.