Effects of Exercise Training on Forearm and Calf Vasodilation and Proinflammatory Markers in Recent Heart Transplant Recipients: a Pilot Study

Background: Aerobic exercise training improves vasodilatory capacity of peripheral resistance vasculature and modifies plasma proinflammatory markers in chronic heart failure patients. It is, however, currently unknown whether aerobic exercise has a similar effect in heart transplant recipients (HTR).

Design And Methods: Eight weeks after transplantation, 14 HTR were randomly assigned to 12 weeks of supervised aerobic exercise training (TRAINED; n=8) or attention-time control (CONTROL; n=6) in addition to posttransplantation medical care. Peak forearm blood flow and calf blood flow (CBF) during reactive hyperemia after 5 min of limb ischemia was used as a measure of endothelium-dependent vasodilation of limb resistance arteries. Plasma C-reactive protein, interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha), soluble intercellular adhesion molecule-1 (sICAM-1), and exercise capacity were measured at baseline and again after 12 weeks in both groups.

Results: Peak CBF increased 22% in the TRAINED (25.9+/-5.8-31.6+/-7.9 ml/min/100 ml, P<0.05), but there was no change in peak CBF after 12 weeks in CONTROL. Plasma C-reactive protein, IL-6, TNF-alpha, sICAM-1 did not change in TRAINED, but there was a significant increase in TNF-alpha (1.66+/-1.02 vs. 3.07+/-1.10 pg/ml, P<0.05), and sICAM-1 (205.9+/-59.1 vs. 245.0+/-47.9 ng/ml, P<0.01) in CONTROL after 12 weeks. Furthermore, exercise test duration improved 51.7% (P<0.01) and there was a trend toward an increase in peak VO2 (P=0.05) in TRAINED after 12 weeks but neither changed in CONTROL.

Conclusion: A program of supervised aerobic exercise improves endothelium-dependent vasodilation of the calf, but not forearm resistance arteries, and may attenuate a progressive increase in selected proinflammatory markers in HTR.