P753Exercise has similar beneficial effect in the mobilization of endothelial progenitor cells in patients with chronic heart failure of different severity
Authors: Kourek C , Karatzanos E , Psarra K , Mitsiou G , Delis D , Linardatou V , Dimopoulos S , Pittaras T , Vasileiadis I , Nanas S 
Published: October 2019

Abstract

Introduction
Vascular endothelial dysfunction is an underlying pathophysiological feature of chronic heart failure (CHF). Exercise has been shown to stimulate the mobilization of endothelial progenitor cells (EPC) in healthy populations. EPC contribute to the regeneration of the inflammatory endothelium and promote neovascularization.

Purpose
The purpose of the present study was to investigate the mobilization of EPC between CHF patients with different severity after a 36-session exercise training program.

Methods
Thirty eight consecutive patients (32 ♂, 6 ♀) with stable CHF [mean±SD, age (years): 56±10, EF (%): 32±9, peak VO2 (ml/kg/min): 18.1±4.1] enrolled a 36-session exercise training program. All patients underwent a symptom limited maximal cardiopulmonary exercise testing (CPET) on a cycle ergometer before and after the training program. Venous blood was sampled before and after each CPET. Five endothelial circulating populations were quantified by flow cytometry (Table 1). Patients were divided in severity groups according to the median values of peak VO2, predicted peak VO2, VE/VCO2 slope and EF. EPC values are expressed as “cells/million enucleated cells” in medians (25th, 75th percentiles).

Results
In all patients, rehabilitation showed a statistical significant effect as well as a significant acute effect in all endothelial circulating populations (p<0.001). Although there was statistical significant mobilization of endothelial circulating populations within each severity group (groups separated by peak VO2), no differences were observed between groups (p>0.05, Table 1). Similar results were also shown for the rest of CPET parameters and EF.
Cellular populations in severity groups Endothelial cellular populations Peak VO2 <18 ml/kg/min Peak VO2 ≥18 ml/kg/min Before rehabilitation After rehabilitation Before rehabilitation After rehabilitation Before CPET After CPET Before CPET After CPET Before CPET After CPET Before CPET After CPET CD34+/CD45–/CD133+ 54 (24–74) 90 (40–104)* 96 (54–120) 154 (100–169)* 37 (16–66) 60 (33–93)* 79 (46–106) 122 (96–159)* CD34+/CD45–/CD133+/VEGFR2 1 (1–3) 3 (2–8)* 8 (4–9) 14 (10–19)* 2 (1–3) 4 (3–8)* 5 (4–7) 13 (9–16)* CD34+/CD133+/VEGFR2 13 (8–18) 13 (9–25) 22 (16–31) 27 (14–38) 10 (7–19) 14 (9–20)** 16 (13–37) 22 (15–62)** CD34+/CD45–/CD133– 186 (131–368) 494 (202–640)* 431 (301–564) 738 (590–921)* 214 (150–270) 306 (233–575)* 434 (277–835) 740 (524–1588)* CD34+/CD45–/CD133–/VEGFR2 2 (1–2) 3 (2–5)* 4 (3–5) 10 (9–14)* 1 (1–1) 3 (2–5)* 4 (2–8) 9 (7–12)* Differences within groups *p<0.001, **p<0.05.

Conclusion
A 36-session training program stimulates the long term mobilization of EPC in CHF patients. This mobilization seems to be similar in all patients irrespective of their severity. The clinical relevance of these findings and the potential mechanisms need further investigation.

Acknowledgement/Funding
Greece and the European Union (European Social Fund-ESF) through the Operational Programme “Human Resources Development, Education, Lifelong Learning”