Exercise-based cardiac rehabilitation improves endothelial function assessed by flow-mediated dilation but not by pulse amplitude tonometry

We aimed to investigate the effect of exercise on endothelium-dependent vasodilator function assessed simultaneously in the brachial artery and in the distal arterial bed by flow-mediated dilation and the pulse amplitude tonometry method, respectively, in coronary artery disease patients. The study included 146 patients with stable coronary artery disease (123 men, mean age 62 +/- 9 years) who participated in the Cardiac Rehabilitation and Genetics of Exercise performance study. All patients completed a 12-week supervised cardiac rehabilitation programme (three sessions per week at an intensity of 80% of the heart rate reserve). At baseline and upon completion of the training, we measured brachial artery diameters by means of ultrasound scanning (linear array transducer of 12MHz) and simultaneously assessed pulse amplitudes in the fingertip using a pulse amplitude tonometry device both at rest and after reactive hyperaemia induced by a 5-min forearm cuff occlusion. Peak oxygen uptake significantly increased (+22%; p<0.0001) and flow-mediated dilation improved from 10.0% to 13.1% (+37%; p<0.0001), whereas the reactive hyperaemia index of the pulse amplitude tonometry method remained unchanged (p=0.47) following exercise-based cardiac rehabilitation. However, the basal digital pulse amplitude (+58%; p<0.001) increased as a result of training, as did the digital pulse amplitude after reactive hyperaemia (+22%; p<0.05). Exercise-based cardiac rehabilitation is associated with an improvement in endothelial function, as can be measured by flow-mediated dilation but not by the reactive hyperaemia index of the pulse amplitude tonometry method.