Effect of High Intensity Exercise on Peak Oxygen Uptake and Endothelial Function in Long-Term Heart Transplant Recipients

Coronary allograft vasculopathy is a well-known long-term complication after cardiac transplantation. Endothelial dysfunction is involved and may be prevented by aerobic exercise. The purpose of this study was to examine whether high intensity aerobic exercise improves peak oxygen uptake (VO2 peak) and endothelial function in heart transplant (HT) recipients. Twenty-seven long-term HT recipients were randomized to either 8-weeks high intensity aerobic exercise or no training. Flow mediated dilation of the brachial artery (FMD) was measured by ultrasound and VO2 peak by the analysis of expired air. Blood pressure and biomarkers were measured before and after 8 weeks. VO2 peak increased significantly in the exercise group (VO2 peak 23.9 +/- 1.79 to 28.3 +/- 1.63 mL/kg/min compared to controls (VO2 peak 24.6 +/- 1.38 to 23.4 +/- 1.58, p < 0.001 exercise vs. control).FMD increased in the exercise group compared to controls (8.3 +/- 1.1% to 11.4 +/- 1.2% vs. 5.6 +/- 1.0% to 5.3 +/- 1.7%, p = 0.024). No increase in nitroglycerin-induced vasodilation was observed. Systolic blood pressure fell in the exercise group (142 +/- 4.2 mmHg to127 +/- 3.4 mmHg, p = 0.01) and was unchanged in controls (141 +/- 4.2 mmHg to 142 +/- 6.4 mmHg, NS). High intensity aerobic exercise reduces systolic blood pressure and improves endothelial function in HT recipients.