Correlation between CD34+ and exercise capacity, functional class, quality of life and norepinephrine in heart failure patients

Abstract

Background: A previous study associated CD34⁺ levels with NYHA functional class in heart failure patients. The aim of this study was to correlate CD34⁺ levels to exercise capacity, functional class, quality of life and norepinephrine in heart failure patients.
Methods: Twenty three sedentary patients (52 ± 7 years, 78% male) answered the Minnesota Living with Heart Failure Questionnaire and rested for 20 minutes before an investigator collect a blood sample. After this, patients performed a cardiopulmonary exercise test to determine the heart rate at anaerobic and ventilatory threshold and oxygen consumption at peak effort, at anaerobic and ventilatory threshold. One other blood sample was collected during the peak effort to investigate the norepinephrine and CD34⁺ levels.
Results: Rest percentage of CD34⁺ did not show correlation with: left ventricle ejection fraction (r = 0.03, p = 0.888), peakVO₂ (r = 0.32, p = 0.13), VO₂ at anaerobic threshold (VO₂AT) (r = 0.03, p = 0.86), VO₂ at ventilatory threshold (VO₂VT) (r = 0.36, p = 0.08), NYHA functional class (r = –0.2, p = 0.35), quality of life (Minnesota) (r = –0.17, p = 0.42). CD34⁺ did not show correlation, either, with: peakVO₂ (r = 0.38, p = 0.06), VO₂AT (r = 0.09, p = 0.65), VO₂VT (r = 0.43, p = 0.4), NYHA functional class (r = –0.13, p=0.54), quality of life (r = 0.00, p = 0.99).
Conclusions: CD34⁺ levels did not correlate with exercise capacity, functional class, quality of life and norepinephrine. Percentage of CD34⁺ levels did not increase during the cardiopulmonary exercise test in heart failure patients.