Changes in Circulating Progenitor Cells Are Associated with Functional Capacity in Heart Failure Patients: A Longitudinal Study

PurposeCirculating progenitor cells (CPCs) are involved in the process of endothelial repair and are a prognostic factor in cardiovascular diseases. We aimed to evaluate the association between serial measurements of CPCs and functional capacity in heart failure (HF) patients.Methods and MaterialsWe included 126 consecutive consenting ambulatory HF patients with reduced left ventricular ejection fraction (LVEF<40%). We evaluated CPCs and functional capacity every 6 months for up to 2 years. CPCs were measured as early-outgrowth colony-forming units (EO-CFU) and circulating CD34+, VEGFR2+ and/or CD133+cells. Functional capacity was measured as peak oxygen consumption (peak VO2). We used mixed-effect models to analyze the independent association between CPCs and peak VO2.ResultsThe mean age was 55±12 years; 29 (23%) patients were female. Forty (35%) patients had ischemic cardiomyopathy. During follow up, a decrease in CD34+VEGFR2+cells was independently associated with increased functional capacity; a 10-cell decrease in CD34+VEGFR2+cells was associated with an increase of 0.2 ml/kg/min in peak VO2 (p<0.05). We found an interaction effect (p=0.02) between EO-CFUs and diabetes: in non-diabetics a 10-EO-CFU increase was independently associated with an increase in peak VO2 of 0.28 ml/kg/min (p=0.01), and in diabetics a decrease, rather than an increase in EO-CFUs, was associated with an increased peak VO2 (p<0.05).ConclusionsHigher EO-CFU and lower circulating CD34+VEGFR2+cells are associated with improvements in functional capacity in non-diabetic HF patients. Improved vascular angiogenic capacity could be associated with better functional capacity in HF patients. In diabetics, lower EO-CFUs were associated with improved functional capacity suggesting a differential behaviour.