Effect of cardiac rehabilitation on angiogenic cytokines in postinfarction patients

Objective: To determine whether cardiac rehabilitation influences plasma levels of angiogenic cytokines and their correlation with myocardial blood flow (MBF). Design: Randomised controlled study. Setting: Tertiary cardiac centre. Patients: 39 postinfarction patients randomised to either a 3-month training group (n=20) or a non-training group (n=19), and 19 normal controls. Interventions: Cardiac rehabilitation. Main outcome measures: MBF by cardiac magnetic resonance imaging, and plasma levels of stem cell factor (SCF), stromal-derived factor-1 (SDF-1), and vascular endothelial growth factor (VEGF) measured at enrolment and at 3 months after randomisation. Results: At baseline, when compared with the healthy subjects, postinfarction patients had a lower MBF in the infarcted myocardium during dipyridamole-induced stress (1.65 (0.58) vs 2.77 (0.78) ml/min/g, p<0.001) but higher plasma levels of VEGF (3.65 (0.75) vs 2.77 (0.59) pg/ml, p<0.001 expressed as the natural logarithm) and SDF-1 (2113 (345) vs 1869 (309) pg/ml, p=0.009). Only SDF- 1 was inversely associated with stress MBF in both remote (r=-0.39, p=0.03) and infarcted myocardium (r=-0.62, p<0.001). After 3 months, the training group's stress MBF had increased by 33% in the remote (p<0.001) and 28% in infarcted myocardium (p=0.02), while VEGF decreased by 9% (p=0.01), and SDF-1 decreased by 11% (p=0.02). The change in SDF-1 was inversely correlated with the change in stress MBF in both remote (r=-0.40, p=0.01) and infarcted myocardium (r=-0.50, p=0.001). In the non-training group, MBF and cytokines were unchanged. Conclusion: Cardiac rehabilitation improves stress MBF in postinfarction patients, with an inverse decrease in circulating angiogenic cytokines.